Haemocytes control stem cell activity in the Drosophila intestine.

PubMed

Ayyaz, Arshad; Li, Hongjie; Jasper, Heinrich

2015-06-01

Coordination of stem cell activity with inflammatory responses is critical for regeneration and homeostasis of barrier epithelia. The temporal sequence of cell interactions during injury-induced regeneration is only beginning to be understood. Here we show that intestinal stem cells (ISCs) are regulated by macrophage-like haemocytes during the early phase of regenerative responses of the Drosophila intestinal epithelium. On tissue damage, haemocytes are recruited to the intestine and secrete the BMP homologue DPP, inducing ISC proliferation by activating the type I receptor Saxophone and the Smad homologue SMOX. Activated ISCs then switch their response to DPP by inducing expression of Thickveins, a second type I receptor that has previously been shown to re-establish ISC quiescence by activating MAD. The interaction between haemocytes and ISCs promotes infection resistance, but also contributes to the development of intestinal dysplasia in ageing flies. We propose that similar interactions influence pathologies such as inflammatory bowel disease and colorectal cancer in humans.

Innovative application of classic and newer techniques for the characterization of haemocytes in the New Zealand black-footed abalone (Haliotis iris).

PubMed

Grandiosa, Roffi; Mérien, Fabrice; Pillay, Krish; Alfaro, Andrea

2016-01-01

Haemocytes play an important role in innate immune responses within invertebrate organisms. However, identification and quantification of different types of haemocytes can be extremely challenging, and has led to numerous inconsistencies and misinterpretations within the literature. As a step to rectify this issue, we present a comprehensive and detailed approach to characterize haemocytes using a combination of classical (cytochemical and phagocytosis assays with optical microscopy) and novel (flow cytometry with Sysmex XN-1000 and Muse(®) Cell analyser) techniques. The Sysmex XN-1000 is an innovative fluorescent flow cytometric analyser that can effectively detect, identify and count haemocytes, while the Muse(®) Cell analyser provides accurate and rapid haemocyte cell counts and viability. To illustrate this approach, we present the first report on morphological and functional features of New Zealand black-footed abalone (Haliotis iris) haemocyte cells. Two types of haemocytes were identified in this study, including type I (monocyte-like) and type II (lymphocyte-like) cells. Granular cells, which have been reported in other molluscan species, were not detected in H. iris. Cell types were categorized based on shape, size, internal structures and function. The lymphocyte-like haemocytes were the most abundant hemocytes in the haemolymph samples, and they had large nuclei and basic cytoplasms. Monocyte-like cells generally were larger cells compared to lymphocyte-like cells, and had low nucleus-cytoplasm ratios. Monocyte-like cells showed higher phagocytic activity when encountering Zymosan A particles compared to lymphocyte-like cells. The present study provides a comprehensive and accurate new approach to identify and quantify haemocyte cells for future comparative studies on the immune system of abalone and other molluscan species. Copyright © 2015 Elsevier Ltd. All rights reserved.

The pro-apoptotic action of the peptide hormone Neb-colloostatin on insect haemocytes.

PubMed

Czarniewska, E; Mrówczynska, L; Kuczer, M; Rosinski, G

2012-12-15

The gonadoinhibitory peptide hormone Neb-colloostatin was first isolated from ovaries of the flesh fly Neobellieria bullata. This 19-mer peptide is thought to be a cleaved product of a collagen-like precursor molecule that is formed during remodelling of the extracellular matrix. In this study, we report that upon injection of picomolar and nanomolar doses, this peptide exerts a pro-apoptotic action on haemocytes of Tenebrio molitor adults, as visualized by changes in morphology and viability. The F-actin cytoskeleton was found to aggregate into distinctive patches. This may be responsible for the observed inhibition of adhesion of haemocytes and for the stimulation of filopodia formation. However, Neb-colloostatin injection did not induce the formation of autophagic vacuoles. Our results suggest that physiological concentrations of Neb-colloostatin play an important role in controlling the quantity and activity of haemocytes in insect haemolymph. They also suggest that during periods in which Neb-colloostatin is released, this peptide may cause a weakening of the insects' immune system. This is the first report that exposure to a peptide hormone causes apoptosis in insect haemocytes.

Effects of selected synthetic insecticides on the total and differential populations of circulating haemocytes in adults of the red cotton stainer bug Dysdercus koenigii (Fabricius) (Hemiptera: Pyrrhocoridae).

PubMed

Sarwar, Zahid Mahmood; Ijaz, Mamuna; Sabri, Muhammad Altaf; Yousaf, Hasnain; Mohsan, Muhammad

2018-06-01

Red cotton bug, Dysdercus koenigii (Hemiptera: Pyrrhocoridae), has become the major insect pest of various crops, including cotton, and thereby reducing the yield qualitatively and quantitatively and synthetic insecticides belonging to different groups are the major control agents for such insect pests. A laboratory experiment was carried out to evaluate the effect of different conventional insecticides, i.e., imidacloprid, deltamethrin, lambda cyhalothrin, gamma cyhalothrin and cyfluthirn on haemocytes of D. koenigii. The individuals were exposed to insecticides separately and data was recorded after 30 and 60 min of the exposure. The findings of current study depicted chlorpyrifos to be more effective and significant alterations in total haemocyte counts and differential haemocyte counts were observed in the cyfluthirn treated D. koenigii. In addition to this, cell structure was also disrupted as an immune response. Similar studies would also be helpful to understand the defence mechanisms of insects against the xenobiotics which will help to device efficient management tools for D. koenigii.

Candida glabrata: an emerging oral opportunistic pathogen.

PubMed

Li, L; Redding, S; Dongari-Bagtzoglou, A

2007-03-01

Following the widespread use of immunosuppressive therapy and broad-spectrum antimycotic prophylaxis, C. glabrata has emerged as an important opportunistic pathogen in the oral mucosa. In the past, studies on the virulence factors and host-pathogen interactions of this organism were scarce, but continued to rise in recent years. Denture-wearing, immunosuppression, antibiotic therapy, and aging are risk factors for oral colonization or infection with C. glabrata. Compared with C. albicans, C. glabrata exhibits lower oral keratinocyte-adherence capacity, but higher denture-surface-adherence ability. The role of extracellular hydrolase production in the virulence of this organism does not appear to be as important as it is in C. albicans pathogenesis. Although traditionally thought of as a non-transforming yeast organism, both phenotypic switching and pseudohyphal formation have recently been identified in C. glabrata, but their role in pathogenesis is not known. With the exception of granulocyte monocyte colony-stimulating factor, C. glabrata triggers a lower proinflammatory cytokine response in oral epithelial cells than does C. albicans, in a strain-dependent manner. C. glabrata is less susceptible to killing by human beta-defensins than is C. albicans and exhibits various degrees of resistance to the antifungal activity of salivary histatins and mucins. In addition, C. glabrata possesses both innate and acquired resistance against antifungal drugs, due to its ability to modify ergosterol biosynthesis, mitochondrial function, or antifungal efflux. This resistance allows for its relative overgrowth over other susceptible species and may contribute to the recent emergence of C. glabrata infections in chronically immunocompromised populations. Further investigations on the virulence and host-pathogen interactions of C. glabrata are needed to better define the pathogenesis of oral C. glabrata infection in susceptible hosts.

Silver colloidal nanoparticles: antifungal effect against adhered cells and biofilms of Candida albicans and Candida glabrata.

PubMed

Monteiro, D R; Gorup, L F; Silva, S; Negri, M; de Camargo, E R; Oliveira, R; Barbosa, D B; Henriques, M

2011-08-01

The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applied to adhered cells (2 h) or biofilms (48 h) and after 24 h of contact their effect was assessed by enumeration of colony forming units (CFUs) and quantification of total biomass (by crystal violet staining). The MIC results showed that SN were fungicidal against all strains tested at very low concentrations (0.4-3.3 μg ml(-1)). Furthermore, SN were more effective in reducing biofilm biomass when applied to adhered cells (2 h) than to pre-formed biofilms (48 h), with the exception of C. glabrata ATCC, which in both cases showed a reduction ∼90%. Regarding cell viability, SN were highly effective on adhered C. glabrata and respective biofilms. On C. albicans the effect was not so evident but there was also a reduction in the number of viable biofilm cells. In summary, SN may have the potential to be an effective alternative to conventional antifungal agents for future therapies in Candida-associated denture stomatitis.

Synergistic effects of tacrolimus and azole antifungal compounds in fluconazole-susceptible and fluconazole-resistant Candida glabrata isolates.

PubMed

Denardi, Laura Bedin; Mario, Débora Alves Nunes; Loreto, Érico Silva; Santurio, Janio Morais; Alves, Sydney Hartz

2015-03-01

In vitro interaction between tacrolimus (FK506) and four azoles (fluconazole, ketoconazole, itraconazole and voriconazole) against thirty clinical isolates of both fluconazole susceptible and -resistant Candida glabrata were evaluated by the checkerboard microdilution method. Synergistic, indifferent or antagonism interactions were found for combinations of the antifungal agents and FK506. A larger synergistic effect was observed for the combinations of FK506 with itraconazole and voriconazole (43%), followed by that of the combination with ketoconazole (37%), against fluconazole-susceptible isolates. For fluconazole-resistant C. glabrata , a higher synergistic effect was obtained from FK506 combined with ketoconazole (77%), itraconazole (73%), voriconazole (63%) and fluconazole (60%). The synergisms that we observed in vitro , notably against fluconazole-resistant C. glabrata isolates, are promising and warrant further analysis of their applications in experimental in vivo studies.

Probiotic yeast Saccharomyces boulardii (nom. nud.) modulates adhesive properties of Candida glabrata.

PubMed

Tomičić, Zorica; Zupan, Jure; Matos, Tadeja; Raspor, Peter

2016-11-01

Following the widespread use of immunosuppressive therapy together with broad-spectrum antimycotic therapy, the frequency of mucosal and systemic infections caused by the pathogenic yeast Candida glabrata has increased in the past decades. Due to the resistance of C. glabrata to existing azole drugs, it is very important to look for new strategies helping the treatment of such fungal diseases. In this study, we investigated the effect of the probiotic yeast Saccharomyces boulardii (nom. nud.) on C. glabrata adhesion at different temperatures, pH values, and in the presence of fluconazole, itraconazole and amphotericin B. We also studied the adhesion of C. glabrata co-culture with Candida krusei, Saccharomyces cerevisiae, two bacterial probiotics Lactobacillus rhamnosus and Lactobacillus casei The method used to assess adhesion was crystal violet staining. Our results showed that despite the nonadhesiveness of S. boulardii cells, this probiotic significantly affected the adherence ability of C. glabrata This effect was highly dependent on C. glabrata strain and was either antagonistic or synergistic. Regarding the extrinsic factors, temperature did not indicate any significant influence on this S. boulardii modulatory effect, while at high pH and at increased concentrations of antimycotics, S. boulardii did not manage to repress the adhesion of C. glabrata strains. The experiments of C. glabrata co-cultures with other species showed that the adhesiveness of two separate cultures could not be used to predict the adhesiveness of their co-culture. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Developmental changes in haemocyte morphology in response to Staphylococcus aureus and latex beads in the beetle Tenebrio molitor L.

PubMed

Urbański, Arkadiusz; Adamski, Zbigniew; Rosiński, Grzegorz

2018-01-01

The evolutionary success of insects is undoubtedly related to a well-functioning immune system. This is especially apparent during insect development by the adaptation of individuals to the changing risk of infection. In addition, current studies show that the insect immune system is characterized by some specificity in response to natural pathogens (for example, bacteria, viruses or fungi) and artificial challengers (for example, latex beads or nylon filaments). However, developmental changes and the specificity of immune system reactions simultaneously have not been analysed. Thus, the aim of the present research was to determine changes in haemocyte morphology in response to attenuated Staphylococcus aureus and latex beads across each developmental stage of the beetle Tenebrio molitor. The results of the present research clearly showed differences in the morphology of T. molitor haemocytes during development. The haemocytes of larvae and 4-day-old adult males were characterized by the highest adhesion ability, which was expressed as the largest average surface area, filopodia length and number of filopodia. In contrast, the haemocytes of pupae and 30-day-old adult males had a significantly lower value for these morphological parameters, which was probably related to metamorphosis (pupae) and immunosenescence (30-day-old adults). The haemocytes of the tested individuals reacted differently to the presence of S. aureus and latex beads. The presence of S. aureus led to a significant decrease in all previously mentioned morphological parameters in larvae and in both groups of adult individuals. In these groups, incubation of haemocytes with latex beads caused only a slight decrease in surface area and filopodia length and number. This morphological response of haemocytes to biotic and artificial challengers might be related to an increase in the migration abilities of haemocytes during infection. However, the differences in haemocyte reactivity towards S. aureus and

Screening protocol for Torulopsis (Candida) glabrata.

PubMed Central

Land, G; Burke, J; Shelby, C; Rhodes, J; Collett, J; Bennett, I; Johnson, J

1996-01-01

A screening test has been developed for the presumptive identification of Torulopsis (Candida) glabrata from other common clinical isolates of yeast-like fungi. An interlaboratory comparison of a protocol consisting of morphology on cornmeal Tween 80 agar and trehalose fermentation at 42 degrees C was successful in differentiating T. glabrata from other taxa that are frequent or possible clinical isolates. The screening results for 517 clinical yeast isolates, 241 of which were T. glabrata, were compared with their final identification via commercial systems (API20C Yeast Identification System [bioMERIEUX, Hazelwood, Mo.] and Rapid Yeast Identification Panel [Dade Microscan, Sacramento, Calif.]). The trehalose screening test has a sensitivity and a specificity of 97.8 and 95.8%, respectively, and a positive predictive value of 97.4% and a negative predictive value of 96.5%. Overall, the trehalose screen had an efficiency rating of 93.9% for ruling in or out T. glabrata. Since T. glabrata represents a substantial part of the workload in a clinical laboratory, a significant reduction in direct and indirect costs should be realized. PMID:8862605

Assessing the genotoxic effects of two lipid peroxidation products (4-oxo-2-nonenal and 4-hydroxy-hexenal) in haemocytes and midgut cells of Drosophila melanogaster larvae.

PubMed

Demir, Eşref; Marcos, Ricard

2017-07-01

Lipid peroxidation products can induce tissue damage and are implicated in diverse pathological conditions, including aging, atherosclerosis, brain disorders, cancer, lung and various liver disorders. Since in vivo studies produce relevant information, we have selected Drosophila melanogaster as a suitable in vivo model to characterise the potential risks associated to two lipid peroxidation products namely 4-oxo-2-nonenal (4-ONE) and 4-hydroxy-hexenal (4-HHE). Toxicity, intracellular reactive oxygen species production, and genotoxicity were the end-points evaluated. Haemocytes and midgut cells were the evaluated targets. Results showed that both compounds penetrate the intestine of the larvae, affecting midgut cells, and reaching haemocytes. Significant genotoxic effects, as determined by the comet assay, were observed in both selected cell targets in a concentration/time dependent manner. This study highlights the importance of D. melanogaster as a model organism in the study of the different biological effects caused by lipid peroxidation products entering via ingestion. This is the first study reporting genotoxicity data in haemocytes and midgut cells of D. melanogaster larvae for the two selected compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proteomics of drug resistance in Candida glabrata biofilms.

PubMed

Seneviratne, C Jayampath; Wang, Yu; Jin, Lijian; Abiko, Y; Samaranayake, Lakshman P

2010-04-01

Candida glabrata is a fungal pathogen that causes a variety of mucosal and systemic infections among compromised patient populations with higher mortality rates. Previous studies have shown that biofilm mode of the growth of the fungus is highly resistant to antifungal agents compared with the free-floating or planktonic mode of growth. Therefore, in the present study, we used 2-D DIGE to evaluate the differential proteomic profiles of C. glabrata under planktonic and biofilm modes of growth. Candida glabrata biofilms were developed on polystyrene surfaces and age-matched planktonic cultures were obtained in parallel. Initially, biofilm architecture, viability, and antifungal susceptibility were evaluated. Differentially expressed proteins more than 1.5-fold in DIGE analysis were subjected to MS/MS. The transcriptomic regulation of these biomarkers was evaluated by quantitative real-time PCR. Candida glabrata biofilms were highly resistant to the antifungals and biocides compared with the planktonic mode of growth. Candida glabrata biofilm proteome when compared with its planktonic proteome showed upregulation of stress response proteins, while glycolysis enzymes were downregulated. Similar trend could be observed at transcriptomic level. In conclusion, C. glabrata biofilms possess higher amount of stress response proteins, which may potentially contribute to the higher antifungal resistance seen in C. glabrata biofilms.

Dectin-1 plays an important role in host defense against systemic Candida glabrata infection.

PubMed

Chen, Si Min; Shen, Hui; Zhang, Teng; Huang, Xin; Liu, Xiao Qi; Guo, Shi Yu; Zhao, Jing Jun; Wang, Chun Fang; Yan, Lan; Xu, Guo Tong; Jiang, Yuan Ying; An, Mao Mao

2017-11-17

Candida glabrata is the second most common pathogen of severe candidiasis in immunocompromised hosts, following C. albicans. Although C. glabrata and C. albicans belong to the same genus, they are phylogenetically distinct. C-type lectin receptors (CLRs), acting as pattern-recognition receptors (PRRs), play critical roles in host defense against C. albicans infections. However, our understanding of the specific roles of CLRs in host defense against C. glabrata is limited. Here, we explored the potential roles of the C-type lectins Dectin-1 and Dectin-2 in host defense against C. glabrata. We found that both Dectin-1-deficient mice (Dectin-1 -/- ) and Dectin-2-deficient mice (Dectin-2 -/- ) are more susceptible to C. glabrata infection. Dectin-1confers host higher sensitivity for sensing C. glabrata infections, while the effect of Dectin-2 in the host defense against C. glabrata is infection dose dependent. Dectin-1 is required for host myeloid cells recognition, killing of C. glabrata, and development of subsequent Th1 and Th17 cell-mediated adaptive immune response. Significantly impaired inflammatory responses such as inflammatory cells recruitment and cytokines release that were induced by C. glabrata were manifested in Dectin-1-deficient mice. Together, our study demonstrates that Dectin-1 plays an important role in host defense against systemic Candida glabrata infections, indicating a previous unknown control mechanism for this particular type of infection in host. Our study, therefore, provides new insights into the host defense against C. glabrata.

Epithelial GM-CSF induction by Candida glabrata.

PubMed

Li, L; Dongari-Bagtzoglou, A

2009-08-01

The main cytokine induced by the interaction of oral epithelial cells with C. glabrata is granulocyte monocyte colony-stimulating factor (GM-CSF); however, the mechanisms regulating this response are unknown. Based on previously published information on the interactions of C. albicans with oral epithelial cells, we hypothesized that interaction with viable C. glabrata triggers GM-CSF synthesis via NF-kappaB activation. We found that C. glabrata-induced GM-CSF synthesis was adhesion-dependent, enhanced by endocytosis, and required fungal viability. NF-kappaB activation was noted during interaction of epithelial cells with C. glabrata, and pre-treatment with an NF-kappaB inhibitor partly inhibited GM-CSF synthesis. Blocking TLR4 with anti-TLR4 antibody did not inhibit GM-CSF production. In contrast, an anti-CDw17 antibody triggered significant inhibition of NF-kappaB activation and GM-CSF synthesis. beta-glucans did not stimulate GM-CSF synthesis, suggesting that the CDw17/NF-kappaB/GM-CSF pathway may be beta-glucan-independent. This study provides new insights into the mechanism of GM-CSF induction by C. glabrata.

Assimilation of NAD(+) precursors in Candida glabrata.

PubMed

Ma, Biao; Pan, Shih-Jung; Zupancic, Margaret L; Cormack, Brendan P

2007-10-01

The yeast pathogen Candida glabrata is a nicotinamide adenine dinucleotide (NAD(+)) auxotroph and its growth depends on the environmental supply of vitamin precursors of NAD(+). C. glabrata salvage pathways defined in this article allow NAD(+) to be synthesized from three compounds - nicotinic acid (NA), nicotinamide (NAM) and nicotinamide riboside (NR). NA is salvaged through a functional Preiss-Handler pathway. NAM is first converted to NA by nicotinamidase and then salvaged by the Preiss-Handler pathway. Salvage of NR in C. glabrata occurs via two routes. The first, in which NR is phosphorylated by the NR kinase Nrk1, is independent of the Preiss-Handler pathway. The second is a novel pathway in which NR is degraded by the nucleosidases Pnp1 and Urh1, with a minor role for Meu1, and ultimately converted to NAD(+) via the nicotinamidase Pnc1 and the Preiss-Handler pathway. Using C. glabrata mutants whose growth depends exclusively on the external NA or NR supply, we also show that C. glabrata utilizes NR and to a lesser extent NA as NAD(+) sources during disseminated infection.

Structure-Guided Development of Efficacious Antifungal Agents Targeting Candida Glabrata Dihydrofolate Reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J.; Bolstad, D; Smith, A

2008-01-01

Candida glabrata is a lethal fungal pathogen resistant to many antifungal agents and has emerged as a critical target for drug discovery. Over the past several years, we have been developing a class of propargyl-linked antifolates as antimicrobials and hypothesized that these compounds could be effective inhibitors of dihydrofolate reductase (DHFR) from C. glabrata. We initially screened a small collection of these inhibitors and found modest levels of potency. Subsequently, we determined the crystal structure of C. glabrata DHFR bound to a representative inhibitor with data to 1.6 A resolution. Using this structure, we designed and synthesized second-generation inhibitors. Thesemore » inhibitors bind the C. glabrata DHFR enzyme with subnanomolar potency, display greater than 2000-fold levels of selectivity over the human enzyme, and inhibit the growth of C. glabrata at levels observed with clinically employed therapeutics.« less

Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species

PubMed Central

Nagayoshi, Yohsuke; Shimamura, Shintaro; Nakayama, Hironobu; Minematsu, Asuka; Yamauchi, Shunsuke; Takazono, Takahiro; Nakamura, Shigeki; Yanagihara, Katsunori; Kohno, Shigeru; Mukae, Hiroshi; Izumikawa, Koichi

2017-01-01

The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions. PMID:28700656

Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species.

PubMed

Nagayoshi, Yohsuke; Miyazaki, Taiga; Shimamura, Shintaro; Nakayama, Hironobu; Minematsu, Asuka; Yamauchi, Shunsuke; Takazono, Takahiro; Nakamura, Shigeki; Yanagihara, Katsunori; Kohno, Shigeru; Mukae, Hiroshi; Izumikawa, Koichi

2017-01-01

The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions.

Gastropod-derived haemocyte extracellular traps entrap metastrongyloid larval stages of Angiostrongylus vasorum, Aelurostrongylus abstrusus and Troglostrongylus brevior.

PubMed

Lange, Malin K; Penagos-Tabares, Felipe; Muñoz-Caro, Tamara; Gärtner, Ulrich; Mejer, Helena; Schaper, Roland; Hermosilla, Carlos; Taubert, Anja

2017-01-31

Phagocyte-derived extracellular traps (ETs) were recently demonstrated mainly in vertebrate hosts as an important effector mechanism against invading parasites. In the present study we aimed to characterize gastropod-derived invertebrate extracellular phagocyte trap (InEPT) formation in response to larval stages of important canine and feline metastrongyloid lungworms. Gastropod haemocytes were isolated from the slug species Arion lusitanicus and Limax maximus, and the snail Achatina fulica, and exposed to larval stages of Angiostrongylus vasorum, Aelurostrongylus abstrusus and Troglostrongylus brevior and investigated for gastropod-derived InEPT formation. Phase contrast as well as scanning electron microscopy (SEM) analyses of lungworm larvae-exposed haemocytes revealed ET-like structures to be extruded by haemocytes thereby contacting and ensnaring the parasites. Co-localization studies of haemocyte-derived extracellular DNA with histones and myeloperoxidase in larvae-entrapping structures confirmed classical characteristics of ETs. In vivo exposure of slugs to A. vasorum larvae resulted in InEPTs being extruded from haemocytes in the slug mucous extrapallial space emphasizing the pivotal role of this effector mechanism against invasive larvae. Functional larval entrapment assays demonstrated that almost half of the haemocyte-exposed larvae were contacted or even immobilized by released InEPTs. Overall, as reported for mammalian-derived ETs, different types of InEPTs were here observed, i.e. aggregated, spread and diffused InEPTs. To our knowledge, this study represents the first report on metastrongyloid lungworm-triggered ETosis in gastropods thereby providing evidence of early mollusc host innate immune reactions against invading larvae. These findings will contribute to the better understanding on complex parasite-intermediate host interactions since different gastropod species bear different transmitting capacities for metastrongyloid infections.

Effect of Echinostoma friedi (Trematoda: Echinostomatidae) experimental infection on longevity, growth and fecundity of juvenile Radix peregra (Gastropoda: Lymnaeidae) and Biomphalaria glabrata (Gastropoda: Planorbidae) snails.

PubMed

Muñoz-Antoli, Carla; Marín, Antoni; Toledo, Rafael; Esteban, José-Guillermo

2007-11-01

The effect of Echinostoma friedi experimental infection on longevity, growth and fecundity of two susceptible first intermediate host snails, Radix peregra and Biomphalaria glabrata, was studied to contrast the level of compatibility. 120 R. peregra and 150 B. glabrata snails were used exposed to one, three or five miracidia and divided in three categories: INF (snails exposed and infected); ENI (exposed but not infected) and C (control or not miracidial-exposed snails). R. peregra INF snails' death process starts sooner, but in a prolonged extension, while B. glabrata INF snails have a much shorter life span. The infection and the miracidial exposure are able to reduce R. peregra normal development (stunting). B. glabrata INF snails' growth exceeds that of C snails (gigantism). E. friedi produces a total parasitic castration of R. peregra and B. glabrata INF snails. R. peregra would be considered as the required snail host, while B. glabrata only as an adequate snail host.

Endogenous molecules released by haemocytes receiving Sargassum oligocystum extract lead to downstream activation and synergize innate immunity in white shrimp Litopenaeus vannamei.

PubMed

Shi, Yin-Ze; Chen, Jiann-Chu; Chen, Yu-Yuan; Kuo, Yi-Hsuan; Li, Hui-Fang

2018-05-01

White shrimp Litopenaeus vannamei haemocytes receiving immunostimulating Sargassum oligocystum extract (SE) caused necrosis in haemocyte cells, which released endogenous EM-SE molecules. This study examined the immune response of white shrimp L. vannamei receiving SE and EM-SE in vitro and in vivo. Shrimp haemocytes receiving SE exhibited degranulation, changes in cell size and cell viability, necrosis and a release of EM-SE. Shrimp haemocytes receiving SE, EM-SE, and the SE + EM-SE mixture (SE + EM-SE) increased their phenoloxidase (PO) activity which was significantly higher in shrimp haemocytes receiving the SE + EM-SE mixture. Furthermore, shrimp haemocytes receiving EM-SE showed degranulation and changes in cell size and cell viability. Shrimp receiving SE, EM-SE, and SE + EM-SE all increased their immune parameters, phagocytic activity, clearance efficiency and resistance to Vibrio alginolyticus, being significantly higher in shrimp receiving SE + EM-SE. Meanwhile, the recombinant lipopolysaccharide- and β-1,3-glucan binding protein of L. vannamei (rLvLGBP) was bound to SE, EM-SE, and SE + EM-SE. We conclude that in shrimp haemocytes receiving a non-self molecule, SE in dying cells released EM-SE which led to downstream activation and synergization of the immune response. This study demonstrated that the innate immunity of shrimp was elicited and enhanced by a mixture of endogenous molecules and exogenous substances (or immunostimulants). Copyright © 2018 Elsevier Ltd. All rights reserved.

MALDI-TOF typing highlights geographical and fluconazole resistance clusters in Candida glabrata.

PubMed

Dhieb, C; Normand, A C; Al-Yasiri, M; Chaker, E; El Euch, D; Vranckx, K; Hendrickx, M; Sadfi, N; Piarroux, R; Ranque, S

2015-06-01

Utilizing matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra for Candida glabrata typing would be a cost-effective and easy-to-use alternative to classical DNA-based typing methods. This study aimed to use MALDI-TOF for the typing of C. glabrata clinical isolates from various geographical origins and test its capacity to differentiate between fluconazole-sensitive and -resistant strains.Both microsatellite length polymorphism (MLP) and MALDI-TOF mass spectra of 58 C. glabrata isolates originating from Marseilles (France) and Tunis (Tunisia) as well as collection strains from diverse geographic origins were analyzed. The same analysis was conducted on a subset of C. glabrata isolates that were either susceptible (MIC ≤ 8 mg/l) or resistant (MIC ≥ 64 mg/l) to fluconazole.According to the seminal results, both MALDI-TOF and MLP classifications could highlight C. glabrata population structures associated with either geographical dispersal barriers (p < 10(-5)) or the selection of antifungal drug resistance traits (<10(-5)).In conclusion, MALDI-TOF geographical clustering was congruent with MPL genotyping and highlighted a significant population genetic structure according to fluconazole susceptibility in C. glabrata. Furthermore, although MALDI-TOF and MLP resulted in distinct classifications, MALDI-TOF also classified the isolates with respect to their fluconazole susceptibility profile. Further prospective studies are required to evaluate the capacity of MALDI-TOF typing to investigate C. glabrata infection outbreaks and predict the antifungal susceptibility profile of clinical laboratory isolates. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Candida glabrata Binding to Candida albicans Hyphae Enables Its Development in Oropharyngeal Candidiasis.

PubMed

Tati, Swetha; Davidow, Peter; McCall, Andrew; Hwang-Wong, Elizabeth; Rojas, Isolde G; Cormack, Brendan; Edgerton, Mira

2016-03-01

Pathogenic mechanisms of Candida glabrata in oral candidiasis, especially because of its inability to form hyphae, are understudied. Since both Candida albicans and C. glabrata are frequently co-isolated in oropharyngeal candidiasis (OPC), we examined their co-adhesion in vitro and observed adhesion of C. glabrata only to C. albicans hyphae microscopically. Mice were infected sublingually with C. albicans or C. glabrata individually, or with both species concurrently, to study their ability to cause OPC. Infection with C. glabrata alone resulted in negligible infection of tongues; however, colonization by C. glabrata was increased by co-infection or a pre-established infection with C. albicans. Furthermore, C. glabrata required C. albicans for colonization of tongues, since decreasing C. albicans burden with fluconazole also reduced C. glabrata. C. albicans hyphal wall adhesins Als1 and Als3 were important for in vitro adhesion of C. glabrata and to establish OPC. C. glabrata cell wall protein coding genes EPA8, EPA19, AWP2, AWP7, and CAGL0F00181 were implicated in mediating adhesion to C. albicans hyphae and remarkably, their expression was induced by incubation with germinated C. albicans. Thus, we found a near essential requirement for the presence of C. albicans for both initial colonization and establishment of OPC infection by C. glabrata.

Occurrence of killer Candida glabrata clinical isolates

PubMed Central

Arroyo-Helguera, O; Penas Alejandro, De Las; Irene, Castaño

2012-01-01

In this work we characterized the occurrence of killer activity in 64 Candida glabrata clinical isolates under different conditions. We found that only 6.25 % of the clinical isolates tested were positive for killer activity against a Saccharomyces cerevisiae W303 sensitive strain. Sensitivity of killer activity to different values of pH and temperatures was analyzed. We found that the killer activity presented by all isolates was resistant to every pH and temperature tested, although optimal activity was found at a range of pH values from 4 to 7 and at 37°C. We did not observe extrachromosomal genetic elements associated with killer activity in any of the positive C. glabrata isolates. The killer effect was due to a decrease in viability and DNA fragmentation in sensitive yeast. PMID:24031902

Candida glabrata Binding to Candida albicans Hyphae Enables Its Development in Oropharyngeal Candidiasis

PubMed Central

Tati, Swetha; Davidow, Peter; McCall, Andrew; Hwang-Wong, Elizabeth; Rojas, Isolde G.; Cormack, Brendan; Edgerton, Mira

2016-01-01

Pathogenic mechanisms of Candida glabrata in oral candidiasis, especially because of its inability to form hyphae, are understudied. Since both Candida albicans and C. glabrata are frequently co-isolated in oropharyngeal candidiasis (OPC), we examined their co-adhesion in vitro and observed adhesion of C. glabrata only to C. albicans hyphae microscopically. Mice were infected sublingually with C. albicans or C. glabrata individually, or with both species concurrently, to study their ability to cause OPC. Infection with C. glabrata alone resulted in negligible infection of tongues; however, colonization by C. glabrata was increased by co-infection or a pre-established infection with C. albicans. Furthermore, C. glabrata required C. albicans for colonization of tongues, since decreasing C. albicans burden with fluconazole also reduced C. glabrata. C. albicans hyphal wall adhesins Als1 and Als3 were important for in vitro adhesion of C. glabrata and to establish OPC. C. glabrata cell wall protein coding genes EPA8, EPA19, AWP2, AWP7, and CAGL0F00181 were implicated in mediating adhesion to C. albicans hyphae and remarkably, their expression was induced by incubation with germinated C. albicans. Thus, we found a near essential requirement for the presence of C. albicans for both initial colonization and establishment of OPC infection by C. glabrata. PMID:27029023

Selecting a set of housekeeping genes for quantitative real-time PCR in normal and tetraploid haemocytes of soft-shell clams, Mya arenaria.

PubMed

Siah, A; Dohoo, C; McKenna, P; Delaporte, M; Berthe, F C J

2008-09-01

The transcripts involved in the molecular mechanisms of haemic neoplasia in relation to the haemocyte ploidy status of the soft-shell clam, Mya arenaria, have yet to be identified. For this purpose, real-time quantitative RT-PCR constitutes a sensitive and efficient technique, which can help determine the gene expression involved in haemocyte tetraploid status in clams affected by haemic neoplasia. One of the critical steps in comparing transcription profiles is the stability of selected housekeeping genes, as well as an accurate normalization. In this study, we selected five reference genes, S18, L37, EF1, EF2 and actin, generally used as single control genes. Their expression was analyzed by real-time quantitative RT-PCR at different levels of haemocyte ploidy status in order to select the most stable genes. Using the geNorm software, our results showed that L37, EF1 and S18 represent the most stable gene expressions related to various ploidy status ranging from 0 to 78% of tetraploid haemocytes in clams sampled in North River (Prince Edward Island, Canada). However, actin gene expression appeared to be highly regulated. Hence, using it as a housekeeping gene in tetraploid haemocytes can result in inaccurate data. To compare gene expression levels related to haemocyte ploidy status in Mya arenaria, using L37, EF1 and S18 as housekeeping genes for accurate normalization is therefore recommended.

Haemocytes from Crassostrea gigas and OsHV-1: A promising in vitro system to study host/virus interactions.

PubMed

Morga, Benjamin; Faury, Nicole; Guesdon, Stéphane; Chollet, Bruno; Renault, Tristan

2017-11-01

Since 2008, mass mortality outbreaks associated with the detection of particular variants of OsHV-1 have been reported in Crassostrea gigas spat and juveniles in several countries. Recent studies have reported information on viral replication during experimental infection. Viral DNA and RNA were also detected in the haemolymph and haemocytes suggesting that the virus could circulate through the circulatory system. However, it is unknown if the virus is free in the haemolymph, passively associated at the surface of haemocytes, or able to infect and replicate inside these cells inducing (or not) virion production. In the present study, we collected haemocytes from the haemolymphatic sinus of the adductor muscle of healthy C. gigas spat and exposed them in vitro to a viral suspension. Results showed that viral RNAs were detectable one hour after contact and the number of virus transcripts increased over time in association with an increase of viral DNA detection. These results suggested that the virus is able to initiate replication rapidly inside haemocytes maintained in vitro. These in vitro trials were also used to carry out a dual transcriptomic study. We analyzed concomitantly the expression of some host immune genes and 15 viral genes. Results showed an up regulation of oyster genes currently studied during OsHV-1 infection. Additionally, transmission electron microscopy examination was carried out and did not allow the detection of viral particles. Moreover, All the results suggested that the in vitro model using haemocytes can be valuable for providing new perspective on virus-oyster interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of 17α-methyltestosterone on the reproduction of the freshwater snail Biomphalaria glabrata.

PubMed

Rivero-Wendt, C L G; Borges, A C; Oliveira-Filho, E C; Miranda-Vilela, A L; Ferreira, M F N; Grisolia, C K

2014-01-28

17-α-methyltestosterone (MT) is a synthetic hormone used in fish hatcheries to induce male monosex. Snails hold promise as possible test models to assess chemicals acting on the endocrine system. Biomphalaria glabrata is an aquatic gastropod mollusk (Pulmonata, Planorbidae) that can be easily maintained in aquaria, predisposing the species for use in ecotoxicological testing. This study evaluated the reproductive effects of MT on B. glabrata by examining histological changes and its reproductive performance. Ten snails per group were exposed for 4 weeks to different concentrations of MT (0.01, 0.1, and 1.0 mg/L). The total number of laid eggs, egg mass per group, size of type V oocytes, and production of spermatozoids were determined. Reproduction of B. glabrata was affected by MT. At the lowest concentration (0.01 mg/L), MT caused a statistically significant increase in the number of egg mass per snail compared with controls unexposed to MT. Histopathology analyses showed an increase in the sperm production at the higher MT concentrations of 0.1 and 1.0 mg/L. Chromatographic analyses of water samples showed that MT concentrations rapidly declined within a 96-h period. These results highlight the importance of giving more support to regulatory authorities, since MT is not registered for use on fish hatcheries in many countries around the world. Wastewater from fish farms discharged into aquatic ecosystems should be monitored for MT residues, since its presence could compromise the reproduction of other native snail species.

HSP70 expression in Biomphalaria glabrata snails exposed to cadmium.

PubMed

da Silva Cantinha, Rebeca; Borrely, Sueli Ivone; Oguiura, Nancy; de Bragança Pereira, Carlos Alberto; Rigolon, Marcela M; Nakano, Eliana

2017-06-01

In this study, the effects of the heavy metal cadmium on the stress protein HSP70 are investigated in freshwater mollusks Biomphalaria glabrata. Adult snails were exposed for 96h to CdCl 2 at concentrations ranging from 0.09 to 0.7mgL -1 (LC 50/96h =0.34 (0.30-0.37). Time and concentration-dependent increases in the expression of HSP70 were observed at sub-lethal levels in the immunoblotting assay. Further, an increased survival to a lethal heat shock was observed in animals pre-exposed to a nonlethal concentration of cadmium, evidencing the induction of acquired tolerance. The present study demonstrated the inducibility of B. glabrata HSP70 by cadmium, a relevant environmental contaminant, at non-lethal levels, providing evidences that the assessment of HSP70 in B. glabrata can be regarded as a suitable biomarker for ecotoxicological studies. Copyright © 2017 Elsevier Inc. All rights reserved.

The mating type-like loci of Candida glabrata.

PubMed

Yáñez-Carrillo, Patricia; Robledo-Márquez, Karina A; Ramírez-Zavaleta, Candy Y; De Las Peñas, Alejandro; Castaño, Irene

2014-01-01

Candida glabrata, a haploid and opportunistic fungal pathogen that has not known sexual cycle, has conserved the majority of the genes required for mating and cell type identity. The C. glabrata genome contains three mating-type-like loci called MTL1, MTL2 and MTL3. The three loci encode putative transcription factors, a1, α1 and α2 that regulate cell type identity and sexual reproduction in other fungi like the closely related Saccharomyces cerevisiae. MTL1 can contain either a or α information. MTL2, which contains a information and MTL3 with α information, are relatively close to two telomeres. MTL1 and MTL2 are transcriptionally active, while MTL3 is subject to an incomplete silencing nucleated at the telomere that depends on the silencing proteins Sir2, Sir3, Sir4, yKu70/80, Rif1, Rap1 and Sum1. C. glabrata does not seem to maintain cell type identity, as cell type-specific genes are expressed regardless of the type (or even absence) of mating information. These data highlight important differences in the control of mating and cell type identity between the non-pathogenic yeast S. cerevisiae and C. glabrata, which might explain the absence of a sexual cycle in C. glabrata. The fact that C. glabrata has conserved the vast majority of the genes involved in mating might suggest that some of these genes perhaps have been rewired to control other processes important for the survival inside the host as a commensal or as a human pathogen. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Expression Plasmids for Use in Candida glabrata

PubMed Central

Zordan, Rebecca E.; Ren, Yuxia; Pan, Shih-Jung; Rotondo, Giuseppe; Peñas, Alejandro De Las; Iluore, Joseph; Cormack, Brendan P.

2013-01-01

We describe a series of CEN/ARS episomal plasmids containing different Candida glabrata promoters, allowing for a range of constitutive or regulated expression of proteins in C. glabrata. The set of promoters includes three constitutive promoters (EGD2pr, HHT2pr, PDC1pr), two macrophage/phagocytosis-induced promoters (ACO2pr, LYS21pr), and one nutritionally regulated promoter (MET3pr). Each promoter was cloned into two plasmid backbones that differ in their selectable marker, URA3, or the dominant-selectable NAT1 gene, which confers resistance to the drug nourseothricin. Expression from the 12 resulting plasmids was assessed using GFP as a reporter and flow cytometry or quantitative reverse-transcription polymerase chain reaction to assess expression levels. Together this set of plasmids expands the toolkit of expression vectors available for use with C. glabrata. PMID:23934995

Torulopsis glabrata infections in Singapore: a 4-year study.

PubMed

Tan, R J; Lim, E W; Teo, H K

1977-04-01

During the period 1971-4, Torulopsis glabrata formed 42% of yeasts isolated from 5677 clinical specimens from patients with cancers, diabetes mellitus, chronic renal failure, pregnacy or major surgical operations complicated by mycotic infections. The significance of T. glabrata in these patients is discussed.

[Evaluation of a rapid trehalase test for the identification of Candida glabrata].

PubMed

Kirdar, Sevin; Gültekin, Berna; Evcil, Gonca; Ozkütük, Aydan; Sener, Asli Gamze; Aydin, Neriman

2009-04-01

Candida species which cause local infections, may also lead to fatal systemic infections. The increasing incidence of non-albicans Candida, especially fluconazole susceptible or resistant dose-dependent C. glabrata, increased the importance of rapid and accurate species level identification for Candida. Rapid and correct identification of C. glabrata is essential for the initiation of the appropriate antifungal therapy. This study was conducted to evaluate the performance of the rapid trehalase test in the diagnosis of C. glabrata isolates. A total of 173 Candida strains isolated from various clinical specimens and identified according to germ tube test, growth on cornmeal Tween 80 agar and the colony morphologies on Mast-CHROMagar Candida medium (Mast Diagnostics, UK), were included to the study. The identification of non-albicans Candida species were also confirmed by API 20CAUX (BioMerieux, France) system. Accordingly 86 (50%) of the isolates were identified as C. glabrata, 48 (28%) C. albicans, 17 (10%) C. krusei, 13 (8%) C. tropicalis, 5 (3%) C. parapsilosis, 3 (2%) C. kefyr and 1 (1%) Cutilis. In order to detect the presence of trehalase enzyme in Condida strains, all isolates were grown on Sabouraud dextrose agar containing 4% glucose and then one yeast colony was emulsified in 50 microl of citrate buffer containing 4% (wt/vol) trehalose for 3 h at 37 degrees C. Presence of glucose which emerged after the action of trehalase on trehalose, was detected by a commercial "urinary glucose detection dipstick" (Spinreacta, Spain). All C. glabrata strains yielded positive result by trehalase test. None C. glabrata isolates were found negative by trehalase test except for one strain of C. tropicalis. In this study, the trehalase test allowed identification of C. globrata with 100% sensitivity and 98.9% specificity. It was concluded that trehalase test is a rapid, cost-effective and simple test that can be used for the accurate identification of C. glabrata.

Torulopsis glabrata infections in Singapore: a 4-year study.

PubMed Central

Tan, R. J.; Lim, E. W.; Teo, H. K.

1977-01-01

During the period 1971-4, Torulopsis glabrata formed 42% of yeasts isolated from 5677 clinical specimens from patients with cancers, diabetes mellitus, chronic renal failure, pregnacy or major surgical operations complicated by mycotic infections. The significance of T. glabrata in these patients is discussed. PMID:265338

Reversal of fluconazole resistance induced by a synergistic effect with Acca sellowiana in Candida glabrata strains.

PubMed

R M Machado, Gabriella da; Pippi, Bruna; Dalla Lana, Daiane Flores; Amaral, Ana Paula S; Teixeira, Mário Lettieri; Souza, Kellen C B de; Fuentefria, Alexandre M

2016-11-01

The increased incidence of non-albicans Candida (NAC) resistant to fluconazole (FLZ) makes it necessary to use new therapeutic alternatives. Acca sellowiana (O.berg) Burret (Myrtaceae) is a guava with several proven biological activities. The interaction with fluconazole can be a feasible alternative to overcome this resistance. This study evaluates the in vitro antifungal activity of fractions obtained from the lyophilized aqueous extract of the leaves of A. sellowiana against resistant strains of NAC. The antifungal activity of the fractions was evaluated at 500 μg/mL by microdilution method. Checkerboard assay was performed to determine the effect of the combination of the F2 fraction and antifungal at concentrations: MIC/4, MIC/2, MIC, MIC × 2 and MIC × 4. Candida glabrata showed the lowest MIC values (500-3.90 μg/mL) and the F2 active fraction was the most effective. The association of F2 with FLZ showed a strong synergistic effect (FICI ≤ 0.5) against 100% of C. glabrata resistant isolates. Moreover, the F2 active fraction has demonstrated that probably acts in the cell wall of these yeasts. There was no observed acute dermal toxicity of lyophilized aqueous extract of leaves of A. sellowiana on pig ear skin cells. The interaction between substances present in the F2 active fraction is possibly responsible for the antifungal activity presented by this fraction. This study is unprecedented and suggests that the combination of F2 active fraction and FLZ might be used as an alternative treatment for mucocutaneus infections caused by C. glabrata resistant.

Candida Glabrata Esophagitis: new case reports and management

PubMed Central

Macêdo, Danielle Patrícia Cerqueira; da Silva, Vanessa Karina Alves; de Almeida Farias, Aline Mary; de Melo, Luciana Resende Bandeira; Wilheim, Ana Botler; Neves, Rejane Pereira

2008-01-01

Candida esophagitis (CE) is a common opportunistic infection in the immunocompromised host. C. glabrata is rarely cited as agent of CE and has been underestimated due to lack of proper identification. In this study, two cases of C. glabrata esophagitis in AIDS and chagasic patients are reported. Diagnosis of Candida species should be considered an important key for the ideal choice of antifungal therapy against this mycosis. PMID:24031216

Isolated and combined exposure to ammonia and nitrite in giant freshwater pawn (Macrobrachium rosenbergii): effects on the oxidative stress, antioxidant enzymatic activities and apoptosis in haemocytes.

PubMed

Zhang, Yufan; Ye, Chaoxia; Wang, Anli; Zhu, Xuan; Chen, Changhong; Xian, Jianan; Sun, Zhenzhu

2015-10-01

The residual contaminators such as ammonia and nitrite are widely considered as relevant sources of aquatic environmental pollutants, posing a great threat to shrimp survival. To study the toxicological effects of ammonia and nitrite exposure on the innate immune response in invertebrates, we investigated the oxidative stress and apoptosis in haemocytes of freshwater prawn (Macrobrachium rosenbergii) under isolated and combined exposure to ammonia and nitrite in order to provide useful information about adult prawn immune responses. M. rosenbergii (13.44 ± 2.75 g) were exposed to 0, 5, and 25 mg/L total ammonia-N (TAN) and 0, 5, and 20 mg/L nitrite-N for 24 h. All ammonia concentrations were combined with all nitrite concentrations, making a total of nine treatments studied. Following the exposure treatment, antioxidant enzyme activity, reactive oxygen species (ROS) generation, nitric oxide (NO) generation, and apoptotic cell ratio of haemocytes were measured using flow cytometry. Results indicated that ROS generation was sensitive to the combined effect of ammonia and nitrite, which subsequently affected the Cu-Zn SOD activity. In addition, CAT showed the highest activity at 5 mg/L TAN while GPx decreased at 5 mg/L TAN and returned towards baseline at 25 mg/L. NO generation synchronized with the apoptotic cell ratio in haemocytes, indicating that NO production was closely associated with programmed cell death. Both NO production and apoptotic ratios significantly decreased following 25 mg/L TAN, which may be due to the antagonistic regulation of NO and GPx. We hypothesized that the toxicological effect of nitrite exhibited less change in physiological changes compared to that of ammonia, because of the high tolerance to nitrite exposure in mature M. rosenbergii and/or the competitive effects of chloride ions. Taken together, these results showed that ammonia and nitrite caused a series of combined oxidative stress and apoptosis in M. rosenbergi, but further

Growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of Candida glabrata are affected by different glucose concentrations.

PubMed

Ng, Tzu Shan; Desa, Mohd Nasir Mohd; Sandai, Doblin; Chong, Pei Pei; Than, Leslie Thian Lung

2016-06-01

Glucose is an important fuel source to support many living organisms. Its importance in the physiological fitness and pathogenicity of Candida glabrata, an emerging human fungal pathogen has not been extensively studied. The present study aimed to investigate the effects of glucose on the growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of C. glabrata. In addition, its effect on the expression of a putative high affinity glucose sensor gene, SNF3 was also investigated. Glucose concentrations were found to exert effects on the physiological responses of C. glabrata. The growth rate of the species correlated positively to the amount of glucose. In addition, low glucose environments were found to induce C. glabrata to form biofilm and resist amphotericin B. Conversely, high glucose environments promoted oxidative stress resistance of C. glabrata. The expression of CgSNF3 was found to be significantly up-regulated in low glucose environments. The expression of SNF3 gene in clinical isolates was found to be higher compared to ATCC laboratory strains in low glucose concentrations, which may explain the better survivability of clinical isolates in the low glucose environment. These observations demonstrated the impact of glucose in directing the physiology and virulence fitness of C. glabrata through the possible modulation by SNF3 as a glucose sensor, which in turn aids the species to adapt, survive and thrive in hostile host environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Candida glabrata's Genome Plasticity Confers a Unique Pattern of Expressed Cell Wall Proteins.

PubMed

López-Fuentes, Eunice; Gutiérrez-Escobedo, Guadalupe; Timmermans, Bea; Van Dijck, Patrick; De Las Peñas, Alejandro; Castaño, Irene

2018-06-05

Candida glabrata is the second most common cause of candidemia, and its ability to adhere to different host cell types, to microorganisms, and to medical devices are important virulence factors. Here, we consider three characteristics that confer extraordinary advantages to C. glabrata within the host. (1) C. glabrata has a large number of genes encoding for adhesins most of which are localized at subtelomeric regions. The number and sequence of these genes varies substantially depending on the strain, indicating that C. glabrata can tolerate high genomic plasticity; (2) The largest family of CWPs (cell wall proteins) is the EPA (epithelial adhesin) family of adhesins. Epa1 is the major adhesin and mediates adherence to epithelial, endothelial and immune cells. Several layers of regulation like subtelomeric silencing, cis- acting regulatory regions, activators, nutritional signaling, and stress conditions tightly regulate the expression of many adhesin-encoding genes in C. glabrata , while many others are not expressed. Importantly, there is a connection between acquired resistance to xenobiotics and increased adherence; (3) Other subfamilies of adhesins mediate adherence to Candida albicans , allowing C. glabrata to efficiently invade the oral epithelium and form robust biofilms. It is noteworthy that every C. glabrata strain analyzed presents a unique pattern of CWPs at the cell surface.

The oxidative stress response of the opportunistic fungal pathogen Candida glabrata.

PubMed

Briones-Martin-Del-Campo, Marcela; Orta-Zavalza, Emmanuel; Juarez-Cepeda, Jacqueline; Gutierrez-Escobedo, Guadalupe; Cañas-Villamar, Israel; Castaño, Irene; De Las Peñas, Alejandro

2014-01-01

Organisms have evolved different strategies to respond to oxidative stress generated as a by-product of aerobic respiration and thus maintain the redox homeostasis within the cell. In particular, fungal pathogens are exposed to reactive oxygen species (ROS) when they interact with the phagocytic cells of the host which are the first line of defense against fungal infections. These pathogens have co-opted the enzymatic (catalases, superoxide dismutases (SODs), and peroxidases) and non-enzymatic (glutathione) mechanisms used to maintain the redox homeostasis within the cell, to resist oxidative stress and ensure survival within the host. Several virulence factors have been related to the response to oxidative stress in pathogenic fungi. The opportunistic fungal pathogen Candida glabrata (C. glabrata) is the second most common cause of candidiasis after Candida albicans (C. albicans). C. glabrata has a well defined oxidative stress response (OSR), which include both enzymatic and non-enzymatic mechanisms. C. glabrata OSR is controlled by the well-conserved transcription factors Yap1, Skn7, Msn2 and Msn4. In this review, we describe the OSR of C. glabrata, what is known about its core elements, its regulation and how C. glabrata interacts with the host. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Iron-depletion promotes mitophagy to maintain mitochondrial integrity in pathogenic yeast Candida glabrata

PubMed Central

Nagi, Minoru; Tanabe, Koichi; Nakayama, Hironobu; Ueno, Keigo; Yamagoe, Satoshi; Umeyama, Takashi; Ohno, Hideaki; Miyazaki, Yoshitsugu

2016-01-01

ABSTRACT Candida glabrata, a haploid budding yeast, is the cause of severe systemic infections in immune-compromised hosts. The amount of free iron supplied to C. glabrata cells during systemic infections is severely limited by iron-chelating proteins such as transferrin. Thus, the iron-deficiency response in C. glabrata cells is thought to play important roles in their survival inside the host's body. In this study, we found that mitophagy was induced under iron-depleted conditions, and that the disruption of a gene homologous to ATG32, which is responsible for mitophagy in Saccharomyces cerevisiae, blocked mitophagy in C. glabrata. The mitophagic activity in C. glabrata cells was not detected on short-period exposure to nitrogen-starved conditions, which is a mitophagy-inducing condition used in S. cerevisiae. The mitophagy-deficient atg32Δ mutant of C. glabrata also exhibited decreased longevity under iron-deficient conditions. The mitochondrial membrane potential in Cgatg32Δ cells was significantly lower than that in wild-type cells under iron-depleted conditions. In a mouse model of disseminated infection, the Cgatg32Δ strain resulted in significantly decreased kidney and spleen fungal burdens compared with the wild-type strain. These results indicate that mitophagy in C. glabrata occurs in an iron-poor host tissue environment, and it may contribute to the longevity of cells, mitochondrial quality control, and pathogenesis. PMID:27347716

The Effectiveness of Voriconazole in Therapy of Candida glabrata's Biofilms Oral Infections and Its Influence on the Matrix Composition and Gene Expression.

PubMed

Rodrigues, Célia F; Gonçalves, Bruna; Rodrigues, Maria Elisa; Silva, Sónia; Azeredo, Joana; Henriques, Mariana

2017-08-01

Candida glabrata is one of most prevalent yeast in fungal infections, especially in immunocompromised patients. Its azole resistance results in a low therapeutic response, particularly when associated with biofilms. The main goal of this work was to study the effectiveness of voriconazole (Vcz) against C. glabrata biofilms oral pathologies, as esophageal or oropharyngeal candidiasis. Antifungal susceptibilities were determined in pre-formed 24-h-biofilms and ERG genes expression was determined by qRT-PCR. Protein quantification was performed using BCA ® Kit, carbohydrate was estimated according to the Dubois assay and β-1,3 glucans concentration were determined using Glucatell ® kit. Finally, ergosterol, Vcz, and fluconazole (Flu) concentrations within the biofilm matrices were determined by RP-HPLC. Results showed that C. glabrata biofilms were more susceptible to Vcz than to Flu and that ERG genes expression evidenced an overexpression of the three ERG genes in the presence of both azoles. The matrix content presented a remarked decrease in proteins and an increase in carbohydrates, namely β-1,3 glucans. Ergosterol was successfully detected and quantified in the biofilm matrices, with no differences in all the considered conditions. Vcz demonstrated better diffusion through the biofilms and better cell penetration capacities, than Flu, indicating that the structure of the drug molecule fully influences its dissemination through the biofilm matrices. This work showed that Vcz is notably more effective than Flu for the treatment of resistant C. glabrata oral biofilms, which demonstrates a clinical relevance in its future use for the treatment of oropharyngeal/esophageal candidiasis caused by this species.

A Murine Model of Candida glabrata Vaginitis Shows No Evidence of an Inflammatory Immunopathogenic Response.

PubMed

Nash, Evelyn E; Peters, Brian M; Lilly, Elizabeth A; Noverr, Mairi C; Fidel, Paul L

2016-01-01

Candida glabrata is the second most common organism isolated from women with vulvovaginal candidiasis (VVC), particularly in women with uncontrolled diabetes mellitus. However, mechanisms involved in the pathogenesis of C. glabrata-associated VVC are unknown and have not been studied at any depth in animal models. The objective of this study was to evaluate host responses to infection following efforts to optimize a murine model of C. glabrata VVC. For this, various designs were evaluated for consistent experimental vaginal colonization (i.e., type 1 and type 2 diabetic mice, exogenous estrogen, varying inocula, and co-infection with C. albicans). Upon model optimization, vaginal fungal burden and polymorphonuclear neutrophil (PMN) recruitment were assessed longitudinally over 21 days post-inoculation, together with vaginal concentrations of IL-1β, S100A8 alarmin, lactate dehydrogenase (LDH), and in vivo biofilm formation. Consistent and sustained vaginal colonization with C. glabrata was achieved in estrogenized streptozotocin-induced type 1 diabetic mice. Vaginal PMN infiltration was consistently low, with IL-1β, S100A8, and LDH concentrations similar to uninoculated mice. Biofilm formation was not detected in vivo, and co-infection with C. albicans did not induce synergistic immunopathogenic effects. This data suggests that experimental vaginal colonization of C. glabrata is not associated with an inflammatory immunopathogenic response or biofilm formation.

A Murine Model of Candida glabrata Vaginitis Shows No Evidence of an Inflammatory Immunopathogenic Response

PubMed Central

Nash, Evelyn E.; Peters, Brian M.; Lilly, Elizabeth A.; Noverr, Mairi C.; Fidel, Paul L.

2016-01-01

Candida glabrata is the second most common organism isolated from women with vulvovaginal candidiasis (VVC), particularly in women with uncontrolled diabetes mellitus. However, mechanisms involved in the pathogenesis of C. glabrata-associated VVC are unknown and have not been studied at any depth in animal models. The objective of this study was to evaluate host responses to infection following efforts to optimize a murine model of C. glabrata VVC. For this, various designs were evaluated for consistent experimental vaginal colonization (i.e., type 1 and type 2 diabetic mice, exogenous estrogen, varying inocula, and co-infection with C. albicans). Upon model optimization, vaginal fungal burden and polymorphonuclear neutrophil (PMN) recruitment were assessed longitudinally over 21 days post-inoculation, together with vaginal concentrations of IL-1β, S100A8 alarmin, lactate dehydrogenase (LDH), and in vivo biofilm formation. Consistent and sustained vaginal colonization with C. glabrata was achieved in estrogenized streptozotocin-induced type 1 diabetic mice. Vaginal PMN infiltration was consistently low, with IL-1β, S100A8, and LDH concentrations similar to uninoculated mice. Biofilm formation was not detected in vivo, and co-infection with C. albicans did not induce synergistic immunopathogenic effects. This data suggests that experimental vaginal colonization of C. glabrata is not associated with an inflammatory immunopathogenic response or biofilm formation. PMID:26807975

[Agglutination and phagocytosis of foreign abiotic particles by bluebottle Calliphora vicina haemocytes in vivo. II. Influence of the previous septic immune induction on haemocytic activity].

PubMed

Kind, T V

2010-01-01

The rate of Calliphora vicina haemocytic defense reaction to foreign particles injection depends on the larval age and on the previous bacterial immunization. Immunization of crop-empting larvae induces an evident increase in particles phagocytosis by juvenile plasmatocytes in 24 h after injection. Both the hemogram and the pattern of cellular defense reaction change significantly after crop-empting. Immunized larvae start intensive adhesion of foreign particles to plasmatocytes surface and formation of great aggregations of plasmatocytes (morules) no longer than in 34 min after injection. The period of particle-haemocyte adhesion is short-termed and no more than after 30 min cell aggregates dissociate and adhered charcoal particles pass to thrombocydoidal agglutinates. Unimmunized control larvae of the same age have shown no adhesion and morules formation. In immunized wadering and diapausing larvae, formation of capsules consisting of central thrombocydoidal agglutinate filled with alien particles and adherent plasmatocytes I is intensified. In contrast to moru-les, this capsule formation is not accompanied by charcoal particles adhesion to plasmatocytes. Immunization of mature larvae of C. vicina shown no prominent influence on both the rate of phagocytosis and the hyaline cells differentiation. It might be supposed that the receptors system is complex and the immunization both the mechanisms of foreigners recognition (adhesion, morulation and incapsulation) and the far more lately occurring phagocytosis.

Phenoloxidase activity in larval and juvenile homogenates and adult plasma and haemocytes of bivalve molluscs.

PubMed

Luna-González, Antonio; Maeda-Martínez, Alfonso N; Vargas-Albores, Francisco; Ascencio-Valle, Felipe; Robles-Mungaray, Miguel

2003-10-01

Phenoloxidase (PO) activity was studied in larval and juvenile homogenates and in the plasma and haemocytes of adult Crassostrea gigas, Argopecten ventricosus, Nodipecten subnodosus, and Atrina maura. Samples were tested for the presence of PO activity by incubation with the substrate L-3, 4-dihydroxyphenylalanine using trypsin, alpha-chymotrypsin, laminarin, lipopolysaccharides (LPS), and sodium dodecyl sulphate (SDS) to elicit activation of prophenoloxidase (proPO) system. PO activity was not detected in larval homogenate. In juvenile homogenate, PO activity was found only in C. gigas and N. subnodosus. PO activity was present in adult samples and was enhanced by elicitors in the plasma of all species tested, but in haemocyte lysate supernatant (HLS) of only N. subnodosus. Activation of proPO by laminarin was suppressed by a protease inhibitor cocktail (P-2714) in plasma and HLS of all species tested.

Effect of 60Co gamma radiation on Biomphalaria glabrata (Mollusca, Gastropoda) embryos: mortality, malformation and hatching.

PubMed

Okazaki, K; Andrade Júnior, H F; Kawano, T

1996-08-01

A study was carried out on the radiosensitivity of Biomphalaria glabrata embryos submitted to doses of 5, 10, 15, 20 and 25 Gy of 60Co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. Mortality, malformation and hatching were the parameters used to evaluate the damage induced by ionizing radiation. Estimated LD50 values (15 days) showed that the cleavage stage (4.3 Gy) was approximately four times more radiosensitive than the trochophore stage (17.0 Gy). Susceptibility to malformation induction was higher in the blastula, gastrula and young trochophore stages. Several types of morphogenetic malformations were observed, such as head malformations, exogastrulas, shell malformations, and embryos with everted stomodeum, with nonspecific malformations being the most frequent. The types of malformation induced by radiation probably are not radiation-specific and do not depend on the dose applied. The dose of 15 Gy was sufficient to greatly reduce the number of hatching snails regardless of the embryonic stage irradiated. We conclude that the effect of 60Co gamma radiation on B. glabrata embryos presented a specific pattern.

A surprisingly large RNase P RNA in Candida glabrata

PubMed Central

KACHOURI, RYM; STRIBINSKIS, VILIUS; ZHU, YANGLONG; RAMOS, KENNETH S.; WESTHOF, ERIC; LI, YONG

2005-01-01

We have found an extremely large ribonuclease P (RNase P) RNA (RPR1) in the human pathogen Candida glabrata and verified that this molecule is expressed and present in the active enzyme complex of this hemiascomycete yeast. A structural alignment of the C. glabrata sequence with 36 other hemiascomycete RNase P RNAs (abbreviated as P RNAs) allows us to characterize the types of insertions. In addition, 15 P RNA sequences were newly characterized by searching in the recently sequenced genomes Candida albicans, C. glabrata, Debaryomyces hansenii, Eremothecium gossypii, Kluyveromyces lactis, Kluyveromyces waltii, Naumovia castellii, Saccharomyces kudriavzevii, Saccharomyces mikatae, and Yarrowia lipolytica; and by PCR amplification for other Candida species (Candida guilliermondii, Candida krusei, Candida parapsilosis, Candida stellatoidea, and Candida tropicalis). The phylogenetic comparative analysis identifies a hemiascomycete secondary structure consensus that presents a conserved core in all species with variable insertions or deletions. The most significant variability is found in C. glabrata P RNA in which three insertions exceeding in total 700 nt are present in the Specificity domain. This P RNA is more than twice the length of any other homologous P RNAs known in the three domains of life and is eight times the size of the smallest. RNase P RNA, therefore, represents one of the most diversified noncoding RNAs in terms of size variation and structural diversity. PMID:15987816

Ultrastructural study on Biomphalaria alexandrina haemocytes infected with Schistosoma mansoni in Egypt and its correlation with nitric oxide level.

PubMed

Helal, Eman G; El-Dafrawy, Shadia M; Mohamed, Amira H; Abou-El-Nour, Basma M; Ibrahim, Samah

2014-04-01

Some snails of Biomphalaria alexandrina can resist the infection of Schistosoma mansoni so this study aimed to clearly this mechanism by using light and electron microscopy (EM) and determine the role of Nitric oxide in this mechanism. B. alexandrina snails used in this study were exposed individually to S. mansoni infection according to their response they were classified into susceptible group (shed cercariae) and resistant group (failed to shed cercariae). Snails not exposed to infection were included in this study as control group. Nitric oxide (NO) level was assayed directly in the soluble fraction of B. alexandrina haemolymph supernatants collected from each group of B. alexandrina snails were subjected to NO assay by the Greiss reaction. The level of NO in haemolymph of infected snails was significantly increased (p < 0.001) than both control and non infected snails groups, however, in non infected snails group had significantly (p < 0.05) compared to control group. This study when correlated the changes recognized by EM with NO level the pro apoptotic effect of high level of NO on the haemocytes. Characterization and identification of cell shape of haemocytes in both haemolymph and tissue were examined by light and electron microscopy. Examination of B. alexandrina snail's haemocytes revealed three types of different cells classified according to their shape and granular contents. These cells are granulocytes, amoebocytes and hyalineocytes. Electron microscope study also revealed the important role of granulocytes and amoebocytes as defense mechanism against snail infection. NO is considered an important anti parasite molecule; intra-molluscan stages of parasites switch off host NO defense response.

Comparison of Pathogenesis and Host Immune Responses to Candida glabrata and Candida albicans in Systemically Infected Immunocompetent Mice

PubMed Central

Brieland, Joan; Essig, David; Jackson, Craig; Frank, Doyle; Loebenberg, David; Menzel, Fred; Arnold, Brian; DiDomenico, Beth; Hare, Roberta

2001-01-01

Cytokine-mediated host defense against Candida glabrata infection was compared to that against C. albicans, using immunocompetent murine models of systemic candidiasis. The pathogenesis of infection was evaluated morphologically and by culture of target organs, while the kinetics of induction of cytokine mRNAs and corresponding proteins were determined in kidneys by real-time reverse transcription-PCR and cytokine-specific murine enzyme-linked immunosorbent assays, respectively. Systemic infection with C. glabrata resulted in a chronic, nonfatal infection with recovery of organisms from kidneys, while intravenous inoculation with C. albicans resulted in rapid mortality with logarithmic growth of organisms in kidneys and recovery of C. albicans from the spleen, liver, and lungs. Survival of C. glabrata-infected mice was associated with rapid induction of mRNAs and corresponding immunoreactive proteins for the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-12 (IL-12), and gamma interferon (IFN-γ) and the lack of induction of protein for the anti-inflammatory cytokine IL-10. In contrast, mortality in C. albicans-infected mice was associated with induction of mRNA and corresponding protein for IL-10 but delayed (i.e., TNF-α) or absent (i.e., IL-12 and IFN-γ) induction of immunoreactive proinflammatory cytokines. Mice were subsequently treated with cytokine-specific neutralizing monoclonal antibodies (MAbs) to TNF-α, IL-12, or IFN-γ, and the effect on growth of C. glabrata in kidneys was assessed. Neutralization of endogenous TNF-α resulted in a significant increase in C. glabrata organisms compared to similarly infected mice administered an isotype-matched control MAb, while neutralization of endogenous IL-12 or IFN-γ had no significant effect on C. glabrata replication. These results demonstrate that in response to intravenous inoculation of C. glabrata, immunocompetent mice develop chronic nonfatal renal infections which are

Synergistic and antagonistic effects of immunomodulatory drugs on the action of antifungals against Candida glabrata and Saccharomyces cerevisiae.

PubMed

Tome, Miha; Zupan, Jure; Tomičić, Zorica; Matos, Tadeja; Raspor, Peter

2018-01-01

Candidemia and other forms of invasive fungal infections caused by Candida glabrata and to a lesser extent Saccharomyces cerevisiae are a serious health problem, especially if their steadily rising resistance to the limited range of antifungal drugs is taken into consideration. Various drug combinations are an attractive solution to the resistance problem, and some drug combinations are already common in the clinical environment due to the nature of diseases or therapies. We tested a few of the common antifungal-immunomodulatory drug combinations and evaluated their effect on selected strains of C. glabrata and S. cerevisiae . The combinations were performed using the checkerboard microdilution assay and interpreted using the Loewe additivity model and a model based on the Bliss independence criterion. A synergistic interaction was confirmed between calcineurin inhibitors (Fk506 and cyclosporine A) and antifungals (fluconazole, itraconazole, and amphotericin B). A new antagonistic interaction between mycophenolic acid (MPA) and azole antifungals was discovered in non-resistant strains. A possible mechanism that explains this is induction of the Cdr1 efflux pump by MPA in C. glabrata ATCC 2001. The Pdr1 regulatory cascade plays a role in overall resistance to fluconazole, but it is not essential for the antagonistic interaction. This was confirmed by the Cg pdr1 Δ mutant still displaying the antagonistic interaction between the drugs, although at lower concentrations of fluconazole. This antagonism calls into question the use of simultaneous therapy with MPA and azoles in the clinical environment.

Dissection of Ire1 Functions Reveals Stress Response Mechanisms Uniquely Evolved in Candida glabrata

PubMed Central

Miyazaki, Taiga; Nakayama, Hironobu; Nagayoshi, Yohsuke; Kakeya, Hiroshi; Kohno, Shigeru

2013-01-01

Proper protein folding in the endoplasmic reticulum (ER) is vital in all eukaryotes. When misfolded proteins accumulate in the ER lumen, the transmembrane kinase/endoribonuclease Ire1 initiates splicing of HAC1 mRNA to generate the bZIP transcription factor Hac1, which subsequently activates its target genes to increase the protein-folding capacity of the ER. This cellular machinery, called the unfolded protein response (UPR), is believed to be an evolutionarily conserved mechanism in eukaryotes. In this study, we comprehensively characterized mutant phenotypes of IRE1 and other related genes in the human fungal pathogen Candida glabrata. Unexpectedly, Ire1 was required for the ER stress response independently of Hac1 in this fungus. C. glabrata Ire1 did not cleave mRNAs encoding Hac1 and other bZIP transcription factors identified in the C. glabrata genome. Microarray analysis revealed that the transcriptional response to ER stress is not mediated by Ire1, but instead is dependent largely on calcineurin signaling and partially on the Slt2 MAPK pathway. The loss of Ire1 alone did not confer increased antifungal susceptibility in C. glabrata contrary to UPR-defective mutants in other fungi. Taken together, our results suggest that the canonical Ire1-Hac1 UPR is not conserved in C. glabrata. It is known in metazoans that active Ire1 nonspecifically cleaves and degrades a subset of ER-localized mRNAs to reduce the ER load. Intriguingly, this cellular response could occur in an Ire1 nuclease-dependent fashion in C. glabrata. We also uncovered the attenuated virulence of the C. glabrata Δire1 mutant in a mouse model of disseminated candidiasis. This study has unveiled the unique evolution of ER stress response mechanisms in C. glabrata. PMID:23382685

Synergistic anticandidal activity of menthol in combination with itraconazole and nystatin against clinical Candida glabrata and Candida krusei isolates.

PubMed

Sharifzadeh, Aghil; Khosravi, Ali Reza; Shokri, Hojjatollah; Tari, Paria Samadi

2017-06-01

Candida glabrata (C. glabrata) and C. krusei are now emerging as serious hospital acquired infections in immunocompromised patients. Menthol, a terpenic compound, has been reported to have antifungal activity. The aim of this study was to investigate the effect of menthol in combination with itraconazole or nystatin against C. glabrata and C. krusei isolates. The effects of menthol along with itraconazole and nystatin, were evaluated by the Clinical Laboratory Standards Institute (CLSI) M44-A and CLSI M27-A3 methods. The fractional inhibitory concentration index (FICI) was determined for menthol plus itraconazole and nystatin combinations using the checkerboard method. The mean of minimum inhibitory concentration (MIC) values of menthol, nystatin and itraconazole were 53.2, 2.30 and 1.50 μg/ml for C. glabrata isolates and 121, 1.08 and 0.38 μg/ml for C. krusei isolates, respectively. Menthol in combination with itraconazole or nystatin exhibited the synergistic effects against all species of Candida tested. FICI values for menthol plus itraconazole and nystatin combinations ranged from 0.250 to 0.561 and 0.139 to 0.623 for C. glabrata isolates, and 0.182 to 0.750 and 0.188 to 0.760 for C. krusei, respectively. These results support the potential use of menthol as an anticandidal agent, and it can be used complementarily with other conventional antifungal agents. Copyright © 2017. Published by Elsevier Ltd.

A Host-Pathogen Interaction Screen Identifies ada2 as a Mediator of Candida glabrata Defenses Against Reactive Oxygen Species.

PubMed

Kounatidis, Ilias; Ames, Lauren; Mistry, Rupal; Ho, Hsueh-Lui; Haynes, Ken; Ligoxygakis, Petros

2018-05-04

Candida glabrata ( C. glabrata ) forms part of the normal human gut microbiota but can cause life-threatening invasive infections in immune-compromised individuals. C. glabrata displays high resistance to common azole antifungals, which necessitates new treatments. In this investigation, we identified five C. glabrata deletion mutants ( ∆ada2 , ∆bas1 , ∆ hir3, ∆ino2 and ∆met31 ) from a library of 196 transcription factor mutants that were unable to grow and activate an immune response in Drosophila larvae. This highlighted the importance of these transcription factors in C. glabrata infectivity. Further ex vivo investigation into these mutants revealed the requirement of C. glabrata ADA2 for oxidative stress tolerance. We confirmed this observation in vivo whereby growth of the C. glabrata Δada2 strain was permitted only in flies with suppressed production of reactive oxygen species (ROS). Conversely, overexpression of ADA2 promoted C. glabrata replication in infected wild type larvae resulting in larval killing. We propose that ADA2 orchestrates the response of C. glabrata against ROS-mediated immune defenses during infection. With the need to find alternative antifungal treatment for C. glabrata infections, genes required for survival in the host environment, such as ADA2 , provide promising potential targets. Copyright © 2018 Kounatidis et al.

Candida glabrata olecranon bursitis treated with bursectomy and intravenous caspofungin.

PubMed

Skedros, John G; Keenan, Kendra E; Trachtenberg, Joel D

2013-01-01

Orthopedic surgeons are becoming more involved in the care of patients with septic arthritis and bursitis caused by yeast species. This case report involves a middle-aged immunocompromised female who developed a Candida glabrata septic olecranon bursitis that developed after she received a corticosteroid injection in the olecranon bursa for presumed aseptic bursitis. Candida (Torulopsis) glabrata is the second most frequently isolated Candida species from the bloodstream in the United States. Increased use of fluconazole and other azole antifungal agents as a prophylactic treatment for recurrent Candida albicans infections in immunocompromised individuals is one reason why there appears to be increased resistance of C. glabrata and other nonalbicans Candida (NAC) species to fluconazole. In this patient, this infection was treated with surgery (bursectomy) and intravenous caspofungin, an echinocandin. This rare infectious etiology coupled with this intravenous antifungal treatment makes this case novel among cases of olecranon bursitis caused by yeasts.

Relationship between the Antifungal Susceptibility Profile and the Production of Virulence-Related Hydrolytic Enzymes in Brazilian Clinical Strains of Candida glabrata

PubMed Central

de Oliveira, Jean Carlos Almeida

2017-01-01

Candida glabrata is a facultative intracellular opportunistic fungal pathogen in human infections. Several virulence-associated attributes are involved in its pathogenesis, host-pathogen interactions, modulation of host immune defenses, and regulation of antifungal drug resistance. This study evaluated the in vitro antifungal susceptibility profile to five antifungal agents, the production of seven hydrolytic enzymes related to virulence, and the relationship between these phenotypes in 91 clinical strains of C. glabrata. All C. glabrata strains were susceptible to flucytosine. However, some of these strains showed resistance to amphotericin B (9.9%), fluconazole (15.4%), itraconazole (5.5%), or micafungin (15.4%). Overall, C. glabrata strains were good producers of catalase, aspartic protease, esterase, phytase, and hemolysin. However, caseinase and phospholipase in vitro activities were not detected. Statistically significant correlations were identified between micafungin minimum inhibitory concentration (MIC) and esterase production, between fluconazole and micafungin MIC and hemolytic activity, and between amphotericin B MIC and phytase production. These results contribute to clarify some of the C. glabrata mechanisms of pathogenicity. Moreover, the association between some virulence attributes and the regulation of antifungal resistance encourage the development of new therapeutic strategies involving virulence mechanisms as potential targets for effective antifungal drug development for the treatment of C. glabrata infections. PMID:28814823

Convergent Evolution of Calcineurin Pathway Roles in Thermotolerance and Virulence in Candida glabrata

PubMed Central

Chen, Ying-Lien; Konieczka, Jay H.; Springer, Deborah J.; Bowen, Samantha E.; Zhang, Jing; Silao, Fitz Gerald S.; Bungay, Alice Alma C.; Bigol, Ursela G.; Nicolas, Marilou G.; Abraham, Soman N.; Thompson, Dawn A.; Regev, Aviv; Heitman, Joseph

2012-01-01

Candida glabrata is an emerging human fungal pathogen that is frequently drug tolerant, resulting in difficulties in treatment and a higher mortality in immunocompromised patients. The calcium-activated protein phosphatase calcineurin plays critical roles in controlling drug tolerance, hyphal growth, and virulence in diverse fungal pathogens via distinct mechanisms involving survival in serum or growth at host temperature (37° and higher). Here, we comprehensively studied the calcineurin signaling cascade in C. glabrata and found novel and uncharacterized functions of calcineurin and its downstream target Crz1 in governing thermotolerance, intracellular architecture, and pathogenesis in murine ocular, urinary tract, and systemic infections. This represents a second independent origin of a role for calcineurin in thermotolerant growth of a major human fungal pathogen, distinct from that which arose independently in Cryptococcus neoformans. Calcineurin also promotes survival of C. glabrata in serum via mechanisms distinct from C. albicans and thereby enables establishment of tissue colonization in a murine systemic infection model. To understand calcineurin signaling in detail, we performed global transcript profiling analysis and identified calcineurin- and Crz1-dependent genes in C. glabrata involved in cell wall biosynthesis, heat shock responses, and calcineurin function. Regulators of calcineurin (RCN) are a novel family of calcineurin modifiers, and two members of this family were identified in C. glabrata: Rcn1 and Rcn2. Our studies demonstrate that Rcn2 expression is controlled by calcineurin and Crz1 to function as a feedback inhibitor of calcineurin in a circuit required for calcium tolerance in C. glabrata. In contrast, the calcineurin regulator Rcn1 activates calcineurin signaling. Interestingly, neither Rcn1 nor Rcn2 is required for virulence in a murine systemic infection model. Taken together, our findings show that calcineurin signaling plays

Role of FKS Mutations in Candida glabrata: MIC Values, Echinocandin Resistance, and Multidrug Resistance

PubMed Central

Pham, Cau D.; Iqbal, Naureen; Bolden, Carol B.; Kuykendall, Randall J.; Harrison, Lee H.; Farley, Monica M.; Schaffner, William; Beldavs, Zintars G.; Chiller, Tom M.; Park, Benjamin J.; Cleveland, Angela A.

2014-01-01

Candida glabrata is the second leading cause of candidemia in U.S. hospitals. Current guidelines suggest that an echinocandin be used as the primary therapy for the treatment of C. glabrata disease due to the high rate of resistance to fluconazole. Recent case reports indicate that C. glabrata resistance to echinocandins may be increasing. We performed susceptibility testing on 1,380 isolates of C. glabrata collected between 2008 and 2013 from four U.S. cities, Atlanta, Baltimore, Knoxville, and Portland. Our analysis showed that 3.1%, 3.3%, and 3.6% of the isolates were resistant to anidulafungin, caspofungin, and micafungin, respectively. We screened 1,032 of these isolates, including all 77 that had either a resistant or intermediate MIC value with respect to at least one echinocandin, for mutations in the hot spot regions of FKS1 and FKS2, the major mechanism of echinocandin resistance. Fifty-one isolates were identified with hot spot mutations, 16 in FKS1 and 35 in FKS2. All of the isolates with an FKS mutation except one were resistant to at least one echinocandin by susceptibility testing. Of the isolates resistant to at least one echinocandin, 36% were also resistant to fluconazole. Echinocandin resistance among U.S. C. glabrata isolates is a concern, especially in light of the fact that one-third of those isolates may be multidrug resistant. Further monitoring of U.S. C. glabrata isolates for echinocandin resistance is warranted. PMID:24890592

The CgHaa1-Regulon Mediates Response and Tolerance to Acetic Acid Stress in the Human Pathogen Candida glabrata

PubMed Central

Bernardo, Ruben T.; Cunha, Diana V.; Wang, Can; Pereira, Leonel; Silva, Sónia; Salazar, Sara B.; Schröder, Markus S.; Okamoto, Michiyo; Takahashi-Nakaguchi, Azusa; Chibana, Hiroji; Aoyama, Toshihiro; Sá-Correia, Isabel; Azeredo, Joana; Butler, Geraldine; Mira, Nuno Pereira

2016-01-01

To thrive in the acidic vaginal tract, Candida glabrata has to cope with high concentrations of acetic acid. The mechanisms underlying C. glabrata tolerance to acetic acid at low pH remain largely uncharacterized. In this work, the essential role of the CgHaa1 transcription factor (encoded by ORF CAGL0L09339g) in the response and tolerance of C. glabrata to acetic acid is demonstrated. Transcriptomic analysis showed that CgHaa1 regulates, directly or indirectly, the expression of about 75% of the genes activated under acetic acid stress. CgHaa1-activated targets are involved in multiple physiological functions including membrane transport, metabolism of carbohydrates and amino acids, regulation of the activity of the plasma membrane H+-ATPase, and adhesion. Under acetic acid stress, CgHaa1 increased the activity and the expression of the CgPma1 proton pump and contributed to increased colonization of vaginal epithelial cells by C. glabrata. CgHAA1, and two identified CgHaa1-activated targets, CgTPO3 and CgHSP30, are herein demonstrated to be determinants of C. glabrata tolerance to acetic acid. The protective effect of CgTpo3 and of CgHaa1 was linked to a role of these proteins in reducing the accumulation of acetic acid inside C. glabrata cells. In response to acetic acid stress, marked differences were found in the regulons controlled by CgHaa1 and by its S. cerevisiae ScHaa1 ortholog, demonstrating a clear divergent evolution of the two regulatory networks. The results gathered in this study significantly advance the understanding of the molecular mechanisms underlying the success of C. glabrata as a vaginal colonizer. PMID:27815348

Fluconazole affects the alkali-metal-cation homeostasis and susceptibility to cationic toxic compounds of Candida glabrata.

PubMed

Elicharova, Hana; Sychrova, Hana

2014-08-01

Candida glabrata is a salt-tolerant and fluconazole (FLC)-resistant yeast species. Here, we analyse the contribution of plasma-membrane alkali-metal-cation exporters, a cation/proton antiporter and a cation ATPase to cation homeostasis and the maintenance of membrane potential (ΔΨ). Using a series of single and double mutants lacking CNH1 and/or ENA1 genes we show that the inability to export potassium and toxic alkali-metal cations leads to a slight hyperpolarization of the plasma membrane of C. glabrata cells; this hyperpolarization drives more cations into the cells and affects cation homeostasis. Surprisingly, a much higher hyperpolarization of C. glabrata plasma membrane was produced by incubating cells with subinhibitory concentrations of FLC. FLC treatment resulted in a substantially increased sensitivity of cells to various cationic drugs and toxic cations that are driven into the cell by negative-inside plasma-membrane potential. The effect of the combination of FLC plus cationic drug treatment was enhanced by the malfunction of alkali-metal-cation transporters that contribute to the regulation of membrane potential and cation homeostasis. In summary, we show that the combination of subinhibitory concentrations of FLC and cationic drugs strongly affects the growth of C. glabrata cells. © 2014 The Authors.

Susceptibility of Candida glabrata biofilms to echinocandins: alterations in the matrix composition.

PubMed

Rodrigues, Célia F; Rodrigues, Maria Elisa; Henriques, Mariana

2018-05-25

Candidiases are the most recurrent fungal infections, especially among immunosuppressed patients. Although Candida albicans is still the most widespread isolated species, non-Candida albicans Candida species have been increasing. The goal of this work was to determine the susceptibility of C. glabrata biofilms to echinocandins and to evaluate their effect on the biofilm matrix composition, comparing the results with other Candida species. Drug susceptibilities were assessed through the determination of minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and minimum biofilm eradication concentration (MBEC) of caspofungin (Csf) and micafugin (Mcf). The β-1,3 glucans content of the matrices was assessed after contact with the drugs. The data suggest that, generally, after contact with echinocandins, the concentration of β-1,3 glucans increased. These adjustments in the matrix composition of C. glabrata biofilms and the chemical differences between Csf and Mcf, seem responsible and may determine the effectivity of the drug responses.

Role of FKS Mutations in Candida glabrata: MIC values, echinocandin resistance, and multidrug resistance.

PubMed

Pham, Cau D; Iqbal, Naureen; Bolden, Carol B; Kuykendall, Randall J; Harrison, Lee H; Farley, Monica M; Schaffner, William; Beldavs, Zintars G; Chiller, Tom M; Park, Benjamin J; Cleveland, Angela A; Lockhart, Shawn R

2014-08-01

Candida glabrata is the second leading cause of candidemia in U.S. hospitals. Current guidelines suggest that an echinocandin be used as the primary therapy for the treatment of C. glabrata disease due to the high rate of resistance to fluconazole. Recent case reports indicate that C. glabrata resistance to echinocandins may be increasing. We performed susceptibility testing on 1,380 isolates of C. glabrata collected between 2008 and 2013 from four U.S. cities, Atlanta, Baltimore, Knoxville, and Portland. Our analysis showed that 3.1%, 3.3%, and 3.6% of the isolates were resistant to anidulafungin, caspofungin, and micafungin, respectively. We screened 1,032 of these isolates, including all 77 that had either a resistant or intermediate MIC value with respect to at least one echinocandin, for mutations in the hot spot regions of FKS1 and FKS2, the major mechanism of echinocandin resistance. Fifty-one isolates were identified with hot spot mutations, 16 in FKS1 and 35 in FKS2. All of the isolates with an FKS mutation except one were resistant to at least one echinocandin by susceptibility testing. Of the isolates resistant to at least one echinocandin, 36% were also resistant to fluconazole. Echinocandin resistance among U.S. C. glabrata isolates is a concern, especially in light of the fact that one-third of those isolates may be multidrug resistant. Further monitoring of U.S. C. glabrata isolates for echinocandin resistance is warranted. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Quantitative and ultrastructural changes in the haemocytes of Spodoptera littoralis (Boisd.) treated individually or in combination with Spodoptera littoralis multicapsid nucleopolyhedrovirus (SpliMNPV) and azadirachtin.

PubMed

Shaurub, El-Sayed H; Abd El-Meguid, Afaf; Abd El-Aziz, Nahla M

2014-10-01

The total haemocyte count (THC) and the possible ultrastructural alterations induced in the haemocytes of the fourth larval instars of the Egyptian cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), 96 h post-feeding on a semi-synthetic diet, treated with the LC50 of Spodoptera littoralis multicapsid nucleopolyhedrovirus (SpliMNPV) and the LC50 of azadirachtin alone, and the LC25 of SpliMNPV combined with the LC25 of azadirachtin were studied and compared to the control. Single treatment with the virus and azadirachtin or combined treatment significantly decreased the THC compared to the control. There are five types of haemocytes in S. littoralis: prohaemocytes, plasmatocytes, granulocytes, spherulocytes and oenocytoids. The most common symptoms in granulocytes and plasmatocytes, the main affected cell types, due to viral infection were the presence of virogenic stroma, peripheral dispersion of the chromatin and disappearance of the nucleoli. However, the most common symptoms in these two types of haemocytes due to treatment with azadirachtin were the presence of rough endoplasmic reticulum filled with fibrous materials, due to probably apoptosis, in their cisternae and disorganization of mitochondria (looped, vacuolated and swollen). In addition, the cytoplasm of granulocytes was vacuolated with the appearance of autophagic lysosomes, while plasmatocytes showed ruptured cell membrane and folded nuclear envelope. Combined treatment with the NPV and azadirachtin induced the same pathological changes which were recorded from individual treatment with the virus or azadirachtin to the same haemocytes. It can be concluded that the change in the THC and ultrastructure of granulocytes and plasmatocytes may affect the cellular-mediated immune response in S. littoralis. Moreover, it seems likely that mitochondria were the target site of azadirachtin, as they were affected in both granulocytes and plasmatocytes treated with azadirachtin alone or in

Occurrence of the haemocyte parasite Bonamia sp. in flat oysters Ostrea puelchana farmed in San Antonio Bay (Argentina).

PubMed

Kroeck, Marina A; Montes, Jaime

2005-02-28

Culture of native flat oysters Ostrea puelchana d'Orbigny in San Antonio Bay (San Matías Gulf, Argentina) began in 1995. After elevated mortality (33%) occurred in September 1996, 18 mo after immersion, histopathological analysis and evaluation of parasitic prevalence was carried out. In October 1997, after 31 mo of cultivation, cumulative mortality was 80%, and in December of the same year, when individuals reached marketable size, mortality was 95% and culture was discontinued. The present study describes the haemocytic parasitism that affected O. puelchana, and suggests that a Bonamia sp. was the etiological agent. This parasite should be considered as a different species from Bonamia sp. detected in Australia and New Zealand until more studies are made to determine the correct taxonomy. This work constitutes the first record of this haemocyte parasite in flat oysters from the Argentinean coast.

Engineering of carboligase activity reaction in Candida glabrata for acetoin production.

PubMed

Li, Shubo; Xu, Nan; Liu, Liming; Chen, Jian

2014-03-01

Utilization of Candida glabrata overproducing pyruvate is a promising strategy for high-level acetoin production. Based on the known regulatory and metabolic information, acetaldehyde and thiamine were fed to identify the key nodes of carboligase activity reaction (CAR) pathway and provide a direction for engineering C. glabrata. Accordingly, alcohol dehydrogenase, acetaldehyde dehydrogenase, pyruvate decarboxylase, and butanediol dehydrogenase were selected to be manipulated for strengthening the CAR pathway. Following the rational metabolic engineering, the engineered strain exhibited increased acetoin biosynthesis (2.24 g/L). In addition, through in silico simulation and redox balance analysis, NADH was identified as the key factor restricting higher acetoin production. Correspondingly, after introduction of NADH oxidase, the final acetoin production was further increased to 7.33 g/L. By combining the rational metabolic engineering and cofactor engineering, the acetoin-producing C. glabrata was improved stepwise, opening a novel pathway for rational development of microorganisms for bioproduction. Copyright © 2013. Published by Elsevier Inc.

A viral histone H4 encoded by Cotesia plutellae bracovirus inhibits haemocyte-spreading behaviour of the diamondback moth, Plutella xylostella.

PubMed

Gad, Wael; Kim, Yonggyun

2008-04-01

Histone H4 is highly conserved and forms a central-core nucleosome with H3 in eukaryotic chromatin. Its covalent modification at the protruding N-terminal region from the nucleosomal core can change the chromatin conformation in order to regulate gene expression. A viral H4 was found in the genome of Cotesia plutellae bracovirus (CpBV). The obligate host of the virus is an endoparasitoid wasp, C. plutellae, which parasitizes the diamondback moth, Plutella xylostella, and interrupts host development and immune reactions. CpBV has been regarded as a major source for interrupting the physiological processes during parasitization. CpBV H4 shows high sequence identity with the amino acid sequence of P. xylostella H4 except for an extended N-terminal region (38 aa). This extended N-terminal CpBV H4 contains nine lysine residues. CpBV H4 was expressed in P. xylostella parasitized by C. plutellae. Western blot analysis using a wide-spectrum H4 antibody showed two H4s in parasitized P. xylostella. In parasitized haemocytes, CpBV H4 was detected predominantly in the nucleus and was highly acetylated. The effect of CpBV H4 on haemocytes was analysed by transient expression using a eukaryotic expression vector, which was injected into non-parasitized P. xylostella. Expression of CpBV H4 was confirmed in the transfected P. xylostella by RT-PCR and immunofluorescence assays. Haemocytes of the transfected larvae lost their spreading ability on an extracellular matrix. Inhibition of the cellular immune response by transient expression was reversed by RNA interference using dsRNA of CpBV H4. These results suggest that CpBV H4 plays a critical role in suppressing host immune responses during parasitization.

Systematic Phenotyping of a Large-Scale Candida glabrata Deletion Collection Reveals Novel Antifungal Tolerance Genes

PubMed Central

Hiller, Ekkehard; Istel, Fabian; Tscherner, Michael; Brunke, Sascha; Ames, Lauren; Firon, Arnaud; Green, Brian; Cabral, Vitor; Marcet-Houben, Marina; Jacobsen, Ilse D.; Quintin, Jessica; Seider, Katja; Frohner, Ingrid; Glaser, Walter; Jungwirth, Helmut; Bachellier-Bassi, Sophie; Chauvel, Murielle; Zeidler, Ute; Ferrandon, Dominique; Gabaldón, Toni; Hube, Bernhard; d'Enfert, Christophe; Rupp, Steffen; Cormack, Brendan; Haynes, Ken; Kuchler, Karl

2014-01-01

The opportunistic fungal pathogen Candida glabrata is a frequent cause of candidiasis, causing infections ranging from superficial to life-threatening disseminated disease. The inherent tolerance of C. glabrata to azole drugs makes this pathogen a serious clinical threat. To identify novel genes implicated in antifungal drug tolerance, we have constructed a large-scale C. glabrata deletion library consisting of 619 unique, individually bar-coded mutant strains, each lacking one specific gene, all together representing almost 12% of the genome. Functional analysis of this library in a series of phenotypic and fitness assays identified numerous genes required for growth of C. glabrata under normal or specific stress conditions, as well as a number of novel genes involved in tolerance to clinically important antifungal drugs such as azoles and echinocandins. We identified 38 deletion strains displaying strongly increased susceptibility to caspofungin, 28 of which encoding proteins that have not previously been linked to echinocandin tolerance. Our results demonstrate the potential of the C. glabrata mutant collection as a valuable resource in functional genomics studies of this important fungal pathogen of humans, and to facilitate the identification of putative novel antifungal drug target and virulence genes. PMID:24945925

Evaluation of Four Calcium Channel Blockers as Fluconazole Resistance Inhibitors in Candida glabrata.

PubMed

Alnajjar, Lina M; Bulatova, Nailya R; Darwish, Rula M

2018-04-14

In this study we aimed to evaluate the ability of four calcium channel blockers, verapamil, diltiazem, nicardipine and nifedipine to enhance sensitivity of Candida glabrata strains to fluconazole. The synergistic antifungal effect was examined by checkerboard method; fractional inhibitory concentration index (FIC) was determined. Time-kill curve method was used for the most promising combination to further evaluate the synergetic effects. nicardipine showed additive effect with fluconazole against fluconazole-resistant and fluconazole-susceptible-dose-dependent strains (DSY565 and CBS138) known to express efflux pumps but not against fluconazole-sensitive strains. Nifedipine exhibited additive effect with fluconazole in both checkerboard (0.5< FIC <1) and time-kill curve methods (<2 log10 colony-forming units (CFU)/ml decrease in viable count). Additionally, nifedipine had own antifungal effect consistently against most of the strains used in this study with minimum inhibitory concentration of 8μg/ml. nicardipine showed additive effect with fluconazole in fluconazole-resistant strains of Candida glabrata-most probably via efflux pump inhibition as demonstrated selectively in fluconazole-resistant strains with known efflux pumps. Nifedipine displayed promising antifungal effect alone and additive effects with fluconazole. Copyright © 2018. Published by Elsevier Ltd.

Mitochondrial DNA heteroplasmy in Candida glabrata after mitochondrial transformation.

PubMed

Zhou, Jingwen; Liu, Liming; Chen, Jian

2010-05-01

Genetic manipulation of mitochondrial DNA (mtDNA) is the most direct method for investigating mtDNA, but until now, this has been achieved only in the diploid yeast Saccharomyces cerevisiae. In this study, the ATP6 gene on mtDNA of the haploid yeast Candida glabrata (Torulopsis glabrata) was deleted by biolistic transformation of DNA fragments with a recoded ARG8(m) mitochondrial genetic marker, flanked by homologous arms to the ATP6 gene. Transformants were identified by arginine prototrophy. However, in the transformants, the original mtDNA was not lost spontaneously, even under arginine selective pressure. Moreover, the mtDNA transformants selectively lost the transformed mtDNA under aerobic conditions. The mtDNA heteroplasmy in the transformants was characterized by PCR, quantitative PCR, and Southern blotting, showing that the heteroplasmy was relatively stable in the absence of arginine. Aerobic conditions facilitated the loss of the original mtDNA, and anaerobic conditions favored loss of the transformed mtDNA. Moreover, detailed investigations showed that increases in reactive oxygen species in mitochondria lacking ATP6, along with their equal cell division, played important roles in determining the dynamics of heteroplasmy. Based on our analysis of mtDNA heteroplasmy in C. glabrata, we were able to generate homoplasmic Deltaatp6 mtDNA strains.

OVICIDAL EFFECT OF PIPERACEAE SPECIES ON Biomphalaria glabrata, Schistosoma mansoni HOST

PubMed Central

Rapado, Ludmila Nakamura; Lopes, Priscila Orechio de Moraes; Yamaguchi, Lydia Fumiko; Nakano, Eliana

2013-01-01

SUMMARY Schistosomiasis is a neglected disease with public health importance in tropical and subtropical regions. An alternative to the disease control is the use of molluscicides to eliminate or reduce the intermediate host snail population causing a reduction of transmission in endemic regions. In this study nine extracts from eight Piperaceae species were evaluated against Biomphalaria glabrata embryos at blastula stage. The extracts were evaluated in concentrations ranging from 100 to 10 mg/L. Piper crassinervium and Piper tuberculatum extracts were the most active (100% of mortality at 20 mg/L and 30 mg/L respectively). PMID:24213196

Expression of Candida glabrata adhesins following exposure to chemical preservatives

PubMed Central

Mundy, Renee Domergue; Cormack, Brendan

2014-01-01

In Candida glabrata, an opportunistic yeast pathogen, adherence to host cells is mediated in part by the Epa family of adhesins, which are encoded largely at subtelomeric loci where they are subject to transcriptional silencing. In analyzing the regulation of the subtelomeric EPA6 gene, we found that its transcription is highly induced after exposure to methylparaben, propylparaben or sorbate. These weak acid-related chemicals are widely used as antifungal preservatives in many consumer goods, including over-the-counter (OTC) vaginal products. Culture of C. glabrata in a variety of vaginal products induced expression of EPA6, leading to increased adherence to cultured human cells as well as primary human vaginal epithelial cells. We present evidence that paraben/sorbate-induction of EPA6 expression involves both preservative stress and growth under hypoxic conditions. We further show that activation of EPA6 transcription depends on the Flo8 and Mss11 transcription factors and does not require the classical weak acid transcription factors War1 or Msn2/Msn4. We conclude that exposure of C. glabrata to commonly used preservatives can alter expression of virulence-related genes. PMID:19426114

Relationships between Respiration and Susceptibility to Azole Antifungals in Candida glabrata

PubMed Central

Brun, Sophie; Aubry, Christophe; Lima, Osana; Filmon, Robert; Bergès, Thierry; Chabasse, Dominique; Bouchara, Jean-Philippe

2003-01-01

Over the past two decades, the incidence of infections due to Candida glabrata, a yeast with intrinsic low susceptibility to azole antifungals, has increased markedly. Respiratory deficiency due to mutations in mitochondrial DNA (mtDNA) associated with resistance to azoles frequently occurs in vitro in this species. In order to specify the relationships between respiration and azole susceptibility, the effects of respiratory chain inhibitors on a wild-type isolate of C. glabrata were evaluated. Respiration of blastoconidia was immediately blocked after extemporaneous addition of potassium cyanide, whereas a 4-h preincubation was required for sodium azide. Antifungal susceptibility determined by a disk diffusion method on Casitone agar containing sodium azide showed a significant decrease in the susceptibility to azoles. Biweekly subculturing on Casitone agar supplemented with sodium azide was therefore performed. This resulted after 40 passages in the isolation of a respiration-deficient mutant, as suggested by its lack of growth on glycerol-containing agar. This respiratory deficiency was confirmed by flow cytometric analysis of blastoconidia stained with rhodamine 123 and by oxygraphy. Moreover, transmission electron microscopy and restriction endonuclease analysis of the mtDNA of mutant cells demonstrated the mitochondrial origin of the respiratory deficiency. Finally, this mutant exhibited cross-resistance to all the azoles tested. In conclusion, blockage of respiration in C. glabrata induces decreased susceptibility to azoles, culminating in azole resistance due to the deletion of mtDNA. This mechanism could explain the induction of petite mutations by azole antifungals which have been demonstrated to act directly on the mitochondrial respiratory chain. PMID:12604511

In vivo Candida glabrata biofilm development on foreign bodies in a rat subcutaneous model.

PubMed

Kucharíková, Soňa; Neirinck, Bram; Sharma, Nidhi; Vleugels, Jef; Lagrou, Katrien; Van Dijck, Patrick

2015-03-01

Biofilm studies have been mostly dedicated to the major human fungal pathogen Candida albicans, whereas much less is known about this virulence factor in Candida glabrata, certainly under in vivo conditions. This study provides a deeper understanding of the biofilm development of C. glabrata, its architecture and susceptibility profile to fluconazole and echinocandins. In vitro and in vivo C. glabrata biofilms were developed inside serum-coated triple-lumen catheters placed in 24-well polystyrene plates or implanted subcutaneously in the back of a rat, respectively. Scanning electron microscopy and confocal scanning laser microscopy were used to visualize the biofilm architecture. Quantitative real-time PCR was used to demonstrate the expression profile of EPA1, EPA3, EPA6 and AWP1-AWP7 during in vivo biofilm formation. Mature biofilms were observed within the first 48 h and the amount of biofilm reached its maximum by 6 days. Architecturally, mature C. glabrata biofilms consisted of a thick network of yeast cells embedded in an extracellular matrix. Moreover, in vivo biofilms were susceptible to echinocandin drugs, whereas fluconazole remained ineffective. Gene expression profiling revealed that EPA3, EPA6, AWP2, AWP3 and AWP5 were up-regulated in in vivo biofilms compared with in vitro biofilms. C. glabrata is a unique microorganism, which, despite the lack of transition to the hyphal form, formed thick biofilms inside foreign bodies in vivo. To our knowledge, this is the first study that has described in vivo C. glabrata biofilm development and its architectural changes in detail and provides an insight into the susceptibility profile, as well as the gene expression machinery, of biofilm-associated infections. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Candida krusei and Candida glabrata reduce the filamentation of Candida albicans by downregulating expression of HWP1 gene.

PubMed

de Barros, Patrícia Pimentel; Freire, Fernanda; Rossoni, Rodnei Dennis; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso

2017-07-01

Pathogenicity of Candida albicans is associated with its capacity switch from yeast-like to hyphal growth. The hyphal form is capable to penetrate the epithelial surfaces and to damage the host tissues. Therefore, many investigations have focused on mechanisms that control the morphological transitions of C. albicans. Recently, certain studies have showed that non-albicans Candida species can reduce the capacity of C. albicans to form biofilms and to develop candidiasis in animal models. Then, the objective of this study was to evaluate the effects of Candida krusei and Candida glabrata on the morphogenesis of C. albicans. Firstly, the capacity of reference and clinical strains of C. albicans in forming hyphae was tested in vitro. After that, the expression of HWP1 (hyphal wall protein 1) gene was determined by quantitative real-time PCR (polymerase chain reaction) assay. For both reference and clinical strains, a significant inhibition of the hyphae formation was observed when C. albicans was incubated in the presence of C. krusei or C. glabrata compared to the control group composed only by C. albicans. In addition, the culture mixed of C. albicans-C. krusei or C. albicans-C. glabrata reduced significantly the expression of HWP1 gene of C. albicans in relation to single cultures of this specie. In both filamentation and gene expression assays, C. krusei showed the higher inhibitory activity on the morphogenesis of C. albicans compared to C. glabrata. C. krusei and C. glabrata are capable to reduce the filamentation of C. albicans and consequently decrease the expression of the HWP1 gene.

EVALUATION OF THE MOLLUSCICIDAL POTENTIAL OF HYDROALCOHOLIC EXTRACTS OF Jatropha gossypiifolia Linnaeus, 1753 ON Biomphalaria glabrata (Say, 1818)

PubMed Central

Pereira, Adalberto Alves; França, Clícia Rosane Costa; Oliveira, Dorlam's da Silva; Mendes, Renato Juvino de Aragão; Gonçalves, José de Ribamar Santos; Rosa, Ivone Garros

2014-01-01

The action of extracts from the stem, leaves, and fruit of Jatropha gossypiifolia on Biomphalaria glabrata was studied by analyzing survival, feeding capacity and oviposition ability. The extracts were obtained by macerating the plant parts in 92% ethanol, which were then evaporated until a dry residue was obtained and phytochemically studied. The molluscicidal activity on B. glabrata was investigated using the procedures recommended by WHO (1965). The amount of food ingested and oviposition were measured during each experiment. The extract of leaves from J. gossypiifolia was shown to be a strong molluscicidal agent, causing 100% mortality of B. glabrata, even in the lowest concentration tested, of 25 ppm. Regarding the fruit extract, there was variation in the mortality, depending on the concentration used (100, 75, 50 and 25 ppm). The snails that were in contact with the fruit extract had significant reduction in feeding and number of embryos in comparison to the control. The stem extract did not present molluscicidal activity nor had any influence on the feeding and oviposition abilities of B. glabrata, in the concentrations tested. In conclusion, the extracts of leaves and fruits of J. gossypiifolia investigated in this work show molluscicidal effect and may be sources of useful compounds for the schistosomiasis control. PMID:25351545

Candida glabrata Biofilms: How Far Have We Come?

PubMed Central

Rodrigues, Célia F.; Rodrigues, Maria Elisa; Silva, Sónia; Henriques, Mariana

2017-01-01

Infections caused by Candida species have been increasing in the last decades and can result in local or systemic infections, with high morbidity and mortality. After Candida albicans, Candida glabrata is one of the most prevalent pathogenic fungi in humans. In addition to the high antifungal drugs resistance and inability to form hyphae or secret hydrolases, C. glabrata retain many virulence factors that contribute to its extreme aggressiveness and result in a low therapeutic response and serious recurrent candidiasis, particularly biofilm formation ability. For their extraordinary organization, especially regarding the complex structure of the matrix, biofilms are very resistant to antifungal treatments. Thus, new approaches to the treatment of C. glabrata’s biofilms are emerging. In this article, the knowledge available on C. glabrata’s resistance will be highlighted, with a special focus on biofilms, as well as new therapeutic alternatives to control them. PMID:29371530

Development of a Candida glabrata dominant nutritional transformation marker utilizing the Aspergillus nidulans acetamidase gene (amdS).

PubMed

Fu, Jianmin; Blaylock, Morganne; Wickes, Cameron F; Welte, William; Mehrtash, Adrian; Wiederhold, Nathan; Wickes, Brian L

2016-05-01

The gene encoding Aspergillus nidulans acetamidase (amdS) was placed under control of Candida albicans ACT1 promoter and terminator sequences and then cloned into a plasmid containing C. glabrata ARS10,CEN8 or ARS10+CEN8 sequences. All plasmids transformed C. glabrata wild-type cells to acetamide+, with the ARS-only containing plasmid transforming cells at the highest frequencies (>1.0 × 10(4) transformants μg(-1)). Plasmids were rapidly lost under non-selective conditions with the frequency dependent on chromosomal element, thus recycling the acetamide- phenotype. The amdS plasmid was used to transform a set of clinical isolates resistant to a variety of antifungal drugs. All strains were successfully transformed to the acetamide+ phenotype at high frequency, confirming that this plasmid construct could be used as a simple dominant marker on virtually any strain. Gap repair experiments demonstrated that just as in Saccharomyces cerevisiae, gap repair functions efficiently inC. glabrata, suggesting that C. glabrata has numerous similarities toS. cerevisiae with regard to ease of molecular manipulation. The amdS system is inexpensive and efficient, and combined with existing C. glabrata plasmid elements, confers a high transformation frequency for C. glabrata with a phenotype that can be easily recycled. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

DNA damage in haemocytes and midgut gland cells of Steatoda grossa (Theridiidae) spiders exposed to food contaminated with cadmium.

PubMed

Stalmach, Monika; Wilczek, Grażyna; Wilczek, Piotr; Skowronek, Magdalena; Mędrzak, Monika

2015-03-01

The aim of this study was to assess the genotoxic effects of Cd on haemocytes and midgut gland cells of web-building spiders, Steatoda grossa (Theridiidae), exposed to the metal under laboratory conditions. Analyzes were conducted on adult females and males, fed for four weeks with cadmium-contaminated Drosophila hydei flies, grown on a medium suplemented with 0.25 mM CdCl2. The comet assay, providing a quantitative measure of DNA strand breaks, was used to evaluate the DNA damage caused by the metal. Cadmium content was measured in whole spider bodies by the AAS method. Metal body burden was significantly lower in females (0.25 µgg(-1) dry weight) than in males (3.03 µgg(-1) dry weight), suggesting that females may have more effective mechanisms controlling the uptake of metal, via the digestive tract, or its elimination from the body. Irrespectively of sex, spiders fed prey contaminated with cadmium showed significantly higher values of comet parameters: tail DNA (TDNA), tail length (TL) and olive tail moment (OTM), in comparison with the control. In midgut gland cells, the level of DNA damage was higher for males than females, while in haemocytes the genotoxic effect of cadmium was greater in females. The obtained results indicate that in spiders cadmium displays strong genotoxic effects and may cause DNA damage even at low concentrations, however the severity of damage seems to be sex- and internal organ-dependent. The comet assay can be considered a sensitive tool for measuring the deleterious effect of cadmium on DNA integrity in spiders. Copyright © 2014 Elsevier Inc. All rights reserved.

Multifunctional centromere binding factor 1 is essential for chromosome segregation in the human pathogenic yeast Candida glabrata.

PubMed

Stoyan, T; Gloeckner, G; Diekmann, S; Carbon, J

2001-08-01

The CBF1 (centromere binding factor 1) gene of Candida glabrata was cloned by functional complementation of the methionine biosynthesis defect of a Saccharomyces cerevisiae cbf1 deletion mutant. The C. glabrata-coded protein, CgCbf1, contains a basic-helix-loop-helix leucine zipper domain and has features similar to those of other budding yeast Cbf1 proteins. CgCbf1p binds in vitro to the centromere DNA element I (CDEI) sequence GTCACATG with high affinity (0.9 x 10(9) M(-1)). Bandshift experiments revealed a pattern of protein-DNA complexes on CgCEN DNA different from that known for S. cerevisiae. We examined the effect of altering the CDEI binding site on CEN plasmid segregation, using a newly developed colony-sectoring assay. Internal deletion of the CDEI binding site led only to a fivefold increase in rates of plasmid loss, indicating that direct binding of Cbf1p to the centromere DNA is not required for full function. Additional deletion of sequences to the left of CDEI, however, led to a 70-fold increase in plasmid loss rates. Deletion of the CBF1 gene proved to be lethal in C. glabrata. C. glabrata cells containing the CBF1 gene under the influence of a shutdown promoter (tetO-ScHOP) arrested their growth after 5 h of cultivation in the presence of the reactive drug doxycycline. DAPI (4',6'-diamidino-2-phenylindole) staining of the arrested cells revealed a significant increase in the number of large-budded cells with single nuclei, 2C DNA content, and short spindles, indicating a defect in the G(2)/M transition of the cell cycle. Thus, we conclude that Cbf1p is required for chromosome segregation in C. glabrata.

The comprehensive immunomodulation of NeurimmiRs in haemocytes of oyster Crassostrea gigas after acetylcholine and norepinephrine stimulation.

PubMed

Chen, Hao; Wang, Lingling; Zhou, Zhi; Hou, Zhanhui; Liu, Zhaoqun; Wang, Weilin; Gao, Dahai; Gao, Qiang; Wang, Mengqiang; Song, Linsheng

2015-11-14

Neural-endocrine-immune (NEI) system is a major modulation network among the nervous, endocrine and immune system and weights greatly in maintaining homeostasis of organisms during stress and infection. Some microRNAs are found interacting with NEI system (designated NeurimmiRs), addressing swift modulations on immune system. The oyster Crassostrea gigas, as an intertidal bivalve, has evolved a primary NEI system. However, the knowledge about NeurimmiRs in oysters remains largely unknown. Six small RNA libraries from haemocytes of oysters stimulated with acetylcholine (ACh) and norepinephrine (NE) were sequenced to identify neurotransmitter-responsive miRNAs and survey their immunomodulation roles. A total of 331 miRNAs (132 identified in the present study plus 199 identified previously) were subjected to expression analysis, and twenty-one and sixteen of them were found ACh- or NE-responsive, respectively (FDR < 0.05). Meanwhile, 21 miRNAs exhibited different expression pattern after ACh or NE stimulation. Consequently, 355 genes were predicted as putative targets of these neurotransmitter-responsive miRNAs in oyster. Through gene onthology analysis, multiple genes involved in death, immune system process and response to stimulus were annotated to be modulated by NeurimmiRs. Besides, a significant decrease in haemocyte phagocytosis and late-apoptosis or necrosis rate was observed after ACh and NE stimulation (p < 0.05) while early-apoptosis rate remained unchanged. A comprehensive immune-related network involving PRRs, intracellular receptors, signaling transducers and immune effectors was proposed to be modulated by ACh- and NE-responsive NeurimmiRs, which would be indispensable for oyster haemocytes to respond against stress and infection. Characterization of the NeurimmiRs would be an essential step to understand the NEI system of invertebrate and the adaptation mechanism of oyster.

Antiestrogenic constituents of the Thai medicinal plants Capparis flavicans and Vitex glabrata.

PubMed

Luecha, Prathan; Umehara, Kaoru; Miyase, Toshio; Noguchi, Hiroshi

2009-11-01

Antiestrogenic compounds were investigated from Thai indigenous plants for galactogogues since estrogen is reported to suppress lactation in breastfeeding women. The aerial parts of the Thai medicinal plant Capparis flavicans, which has traditionally been used to promote lactation, gave the new compound capparoside A (1), along with 28 known compounds. The leaves of Vitex glabrata belong to the same genus as the chaste tree (Vitex agnus-castus), which is used traditionally to support lactation, and afforded the new compounds khainaoside A (14), khainaoside B (15), and khainaoside C (16), together with six known compounds. The isolates were tested for their biological activity using the estrogen-responsive human breast cancer cell lines MCF-7 and T47D. Syringaresinol (3) and principin (6), from C. flavicans, and khainaoside A (14) showed the most potent inhibitory effects on estrogen-enhanced cell proliferation among all compounds isolated. These results suggest that the lactation-promoting properties of C. flavicans might be related to the inhibitory effect on excess estrogen of women who experience insufficient breastfeeding and highlight the possibility of using V. glabrata leaves for their antiestrogenic properties.

Mutants in the Candida glabrata Glycerol Channels Are Sensitized to Cell Wall Stress

PubMed Central

Beese-Sims, Sara E.; Pan, Shih-Jung; Lee, Jongmin; Hwang-Wong, Elizabeth; Cormack, Brendan P.

2012-01-01

Many fungal species use glycerol as a compatible solute with which to maintain osmotic homeostasis in response to changes in external osmolarity. In Saccharomyces cerevisiae, intracellular glycerol concentrations are regulated largely by the high osmolarity glycerol (HOG) response pathway, both through induction of glycerol biosynthesis and control of its flux through the plasma membrane Fps1 glycerol channel. The channel activity of Fps1 is also controlled by a pair of positive regulators, Rgc1 and Rgc2. In this study, we demonstrate that Candida glabrata, a fungal pathogen that possesses two Fps1 orthologs and two Rgc1/-2 orthologs, accumulates glycerol in response to hyperosmotic stress. We present an initial characterization of mutants with deletions in the C. glabrata FPS1 (CAGL0C03267 [www.candidagenome.org]) and FPS2 (CAGL0E03894) genes and find that a double mutant accumulates glycerol, experiences constitutive cell wall stress, and is hypersensitive to treatment by caspofungin, an antifungal agent that targets the cell wall. This mutant is cleared more efficiently in mouse infections than is wild-type C. glabrata by caspofungin treatment. Finally, we demonstrate that one of the C. glabrata RGC orthologs complements an S. cerevisiae rgc1 rgc2 null mutant, supporting the conclusion that this regulatory assembly is conserved between these species. PMID:23087370

Acquired Flucytosine Resistance during Combination Therapy with Caspofungin and Flucytosine for Candida glabrata Cystitis

PubMed Central

El Sissy, Carine; Bachelier-Bassi, Sophie; Scemla, Anne; Quesne, Gilles; Sitterlé, Emilie; Legendre, Christophe; Lortholary, Olivier; Bougnoux, Marie-Elisabeth

2015-01-01

Treatment of Candida glabrata cystitis remains a therapeutic challenge, and an antifungal combination using flucytosine is one option. We describe two patients with refractory C. glabrata cystitis who failed flucytosine combined with caspofungin with early-acquired high-level resistance to flucytosine due to nonsense mutations in the FUR1 gene. Rapidly acquired flucytosine resistance with microbiological failure should discourage combination of caspofungin and flucytosine during urinary candidiasis. PMID:26525799

Generational distribution of a Candida glabrata population: Resilient old cells prevail, while younger cells dominate in the vulnerable host.

PubMed

Bouklas, Tejas; Alonso-Crisóstomo, Luz; Székely, Tamás; Diago-Navarro, Elizabeth; Orner, Erika P; Smith, Kalie; Munshi, Mansa A; Del Poeta, Maurizio; Balázsi, Gábor; Fries, Bettina C

2017-05-01

Similar to other yeasts, the human pathogen Candida glabrata ages when it undergoes asymmetric, finite cell divisions, which determines its replicative lifespan. We sought to investigate if and how aging changes resilience of C. glabrata populations in the host environment. Our data demonstrate that old C. glabrata are more resistant to hydrogen peroxide and neutrophil killing, whereas young cells adhere better to epithelial cell layers. Consequently, virulence of old compared to younger C. glabrata cells is enhanced in the Galleria mellonella infection model. Electron microscopy images of old C. glabrata cells indicate a marked increase in cell wall thickness. Comparison of transcriptomes of old and young C. glabrata cells reveals differential regulation of ergosterol and Hog pathway associated genes as well as adhesion proteins, and suggests that aging is accompanied by remodeling of the fungal cell wall. Biochemical analysis supports this conclusion as older cells exhibit a qualitatively different lipid composition, leading to the observed increased emergence of fluconazole resistance when grown in the presence of fluconazole selection pressure. Older C. glabrata cells accumulate during murine and human infection, which is statistically unlikely without very strong selection. Therefore, we tested the hypothesis that neutrophils constitute the predominant selection pressure in vivo. When we altered experimentally the selection pressure by antibody-mediated removal of neutrophils, we observed a significantly younger pathogen population in mice. Mathematical modeling confirmed that differential selection of older cells is sufficient to cause the observed demographic shift in the fungal population. Hence our data support the concept that pathogenesis is affected by the generational age distribution of the infecting C. glabrata population in a host. We conclude that replicative aging constitutes an emerging trait, which is selected by the host and may even play an

Identification of Candida glabrata genes involved in pH modulation and modification of the phagosomal environment in macrophages.

PubMed

Kasper, Lydia; Seider, Katja; Gerwien, Franziska; Allert, Stefanie; Brunke, Sascha; Schwarzmüller, Tobias; Ames, Lauren; Zubiria-Barrera, Cristina; Mansour, Michael K; Becken, Ulrike; Barz, Dagmar; Vyas, Jatin M; Reiling, Norbert; Haas, Albert; Haynes, Ken; Kuchler, Karl; Hube, Bernhard

2014-01-01

Candida glabrata currently ranks as the second most frequent cause of invasive candidiasis. Our previous work has shown that C. glabrata is adapted to intracellular survival in macrophages and replicates within non-acidified late endosomal-stage phagosomes. In contrast, heat killed yeasts are found in acidified matured phagosomes. In the present study, we aimed at elucidating the processes leading to inhibition of phagosome acidification and maturation. We show that phagosomes containing viable C. glabrata cells do not fuse with pre-labeled lysosomes and possess low phagosomal hydrolase activity. Inhibition of acidification occurs independent of macrophage type (human/murine), differentiation (M1-/M2-type) or activation status (vitamin D3 stimulation). We observed no differential activation of macrophage MAPK or NFκB signaling cascades downstream of pattern recognition receptors after internalization of viable compared to heat killed yeasts, but Syk activation decayed faster in macrophages containing viable yeasts. Thus, delivery of viable yeasts to non-matured phagosomes is likely not triggered by initial recognition events via MAPK or NFκB signaling, but Syk activation may be involved. Although V-ATPase is abundant in C. glabrata phagosomes, the influence of this proton pump on intracellular survival is low since blocking V-ATPase activity with bafilomycin A1 has no influence on fungal viability. Active pH modulation is one possible fungal strategy to change phagosome pH. In fact, C. glabrata is able to alkalinize its extracellular environment, when growing on amino acids as the sole carbon source in vitro. By screening a C. glabrata mutant library we identified genes important for environmental alkalinization that were further tested for their impact on phagosome pH. We found that the lack of fungal mannosyltransferases resulted in severely reduced alkalinization in vitro and in the delivery of C. glabrata to acidified phagosomes. Therefore, protein

Production of White Colonies on CHROMagar Candida(TM) by Members of the Candida glabrata Clade and Other Species with Overlapping Phenotypic Traits

USDA-ARS?s Scientific Manuscript database

We hypothesized that species of the Candida glabrata clade and species with phenotypic traits overlapping with C. glabrata would produce white colonies on CHROMagar Candida. Of 154 isolates (seven species) tested, C. bracarensis, C. nivariensis, C. norvegensis, C. glabrata, and C. inconspicua produ...

Relative Abundances of Candida albicans and Candida glabrata in In Vitro Coculture Biofilms Impact Biofilm Structure and Formation.

PubMed

Olson, Michelle L; Jayaraman, Arul; Kao, Katy C

2018-04-15

Candida is a member of the normal human microbiota and often resides on mucosal surfaces such as the oral cavity or the gastrointestinal tract. In addition to their commensality, Candida species can opportunistically become pathogenic if the host microbiota is disrupted or if the host immune system becomes compromised. An important factor for Candida pathogenesis is its ability to form biofilm communities. The two most medically important species- Candida albicans and Candida glabrata -are often coisolated from infection sites, suggesting the importance of Candida coculture biofilms. In this work, we report that biofilm formation of the coculture population depends on the relative ratio of starting cell concentrations of C. albicans and C. glabrata When using a starting ratio of C. albicans to C. glabrata of 1:3, ∼6.5- and ∼2.5-fold increases in biofilm biomass were observed relative to those of a C. albicans monoculture and a C. albicans / C. glabrata ratio of 1:1, respectively. Confocal microscopy analysis revealed the heterogeneity and complex structures composed of long C. albicans hyphae and C. glabrata cell clusters in the coculture biofilms, and reverse transcription-quantitative PCR (qRT-PCR) studies showed increases in the relative expression of the HWP1 and ALS3 adhesion genes in the C. albicans / C. glabrata 1:3 biofilm compared to that in the C. albicans monoculture biofilm. Additionally, only the 1:3 C. albicans / C. glabrata biofilm demonstrated an increased resistance to the antifungal drug caspofungin. Overall, the results suggest that interspecific interactions between these two fungal pathogens increase biofilm formation and virulence-related gene expression in a coculture composition-dependent manner. IMPORTANCE Candida albicans and Candida glabrata are often coisolated during infection, and the occurrence of coisolation increases with increasing inflammation, suggesting possible synergistic interactions between the two Candida species in

Ulcerative Vaginitis Due to Torulopsis Glabrata: A Case Report

PubMed Central

Clark, John F. J.; Faggett, Timothy; Peters, Barbara; Sampson, Calvin C.

1978-01-01

A patient with ulcerative vaginitis is presented. The differential diagnosis included malignant ulcer, chancroid, and granuloma venereum. Torulopsis glabrata vaginitis, which was subsequently proven, responded successfully to clotrimazole suppositories. Predisposing and related factors and isolation and identification procedures are discussed. PMID:569709

Glycogen synthase kinase-3 (GSK3) regulates TNF production and haemocyte phagocytosis in the immune response of Chinese mitten crab Eriocheir sinensis.

PubMed

Li, Xiaowei; Jia, Zhihao; Wang, Weilin; Wang, Lingling; Liu, Zhaoqun; Yang, Bin; Jia, Yunke; Song, Xiaorui; Yi, Qilin; Qiu, Limei; Song, Linsheng

2017-08-01

Glycogen synthase kinase-3 (GSK3) is a serine/threonine protein kinase firstly identified as a regulator of glycogen synthesis. Recently, it has been proved to be a key regulator of the immune reaction. In the present study, a GSK3 homolog gene (designated as EsGSK3) was cloned from Chinese mitten crab, Eriocheir sinensis. The open reading frame (ORF) was 1824 bp, which encoded a predicted polypeptide of 607 amino acids. There was a conserved Serine/Threonine Kinase domain and a DNA binding domain found in EsGSK3. Phylogenetic analysis showed that EsGSK3 was firstly clustered with GSK3-β from oriental river prawn Macrobrachium nipponense in the invertebrate branch, while GSK3s from vertebrates formed the other distinct branch. EsGSK3 mRNA transcripts could be detected in all tested tissues of the crab including haepatopancreas, eyestalk, muscle, gonad, haemocytes and haematopoietic tissue with the highest expression level in haepatopancreas. And EsGSK3 protein was mostly detected in the cytoplasm of haemocyte by immunofluorescence analysis. The expression levels of EsGSK3 mRNA increased significantly at 6 h after Aeromonas hydrophila challenge (p < 0.05) in comparison with control group, and then gradually decreased to the initial level at 48 h (p > 0.05). The mRNA expression of lipopolysaccharide-induced tumor necrosis factor (TNF)-α factor (EsLITAF) was also induced by A. hydrophila challenge. However, the mRNA expression of EsLITAF and TNF-α production was significantly suppressed after EsGSK3 was blocked in vivo with specific inhibitor lithium, while the phagocytosis of crab haemocytes was significantly promoted. These results collectively demonstrated that EsGSK3 could regulate the innate immune responses of E. sinensis by promoting TNF-α production and inhibiting haemocyte phagocytosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among Candida glabrata Clinical Strains Associated with In Vivo Persistence.

PubMed

Ben-Ami, Ronen; Zimmerman, Offer; Finn, Talya; Amit, Sharon; Novikov, Anna; Wertheimer, Noa; Lurie-Weinberger, Mor; Berman, Judith

2016-08-02

Candida glabrata causes persistent infections in patients treated with fluconazole and often acquires resistance following exposure to the drug. Here we found that clinical strains of C. glabrata exhibit cell-to-cell variation in drug response (heteroresistance). We used population analysis profiling (PAP) to assess fluconazole heteroresistance (FLC(HR)) and to ask if it is a binary trait or a continuous phenotype. Thirty (57.6%) of 52 fluconazole-sensitive clinical C. glabrata isolates met accepted dichotomous criteria for FLC(HR) However, quantitative grading of FLC(HR) by using the area under the PAP curve (AUC) revealed a continuous distribution across a wide range of values, suggesting that all isolates exhibit some degree of heteroresistance. The AUC correlated with rhodamine 6G efflux and was associated with upregulation of the CDR1 and PDH1 genes, encoding ATP-binding cassette (ABC) transmembrane transporters, implying that HetR populations exhibit higher levels of drug efflux. Highly FLC(HR) C. glabrata was recovered more frequently than nonheteroresistant C. glabrata from hematogenously infected immunocompetent mice following treatment with high-dose fluconazole (45.8% versus 15%, P = 0.029). Phylogenetic analysis revealed some phenotypic clustering but also variations in FLC(HR) within clonal groups, suggesting both genetic and epigenetic determinants of heteroresistance. Collectively, these results establish heteroresistance to fluconazole as a graded phenotype associated with ABC transporter upregulation and fluconazole efflux. Heteroresistance may explain the propensity of C. glabrata for persistent infection and the emergence of breakthrough resistance to fluconazole. Heteroresistance refers to variability in the response to a drug within a clonal cell population. This phenomenon may have crucial importance for the way we look at antimicrobial resistance, as heteroresistant strains are not detected by standard laboratory susceptibility testing

A rare case of fungal endocarditis caused by Candida glabrata after completion of antibiotic therapy for Streptococcus endocarditis.

PubMed

Tsugu, Toshimitsu; Murata, Mitsushige; Iwanaga, Shiro; Kitamura, Yohei; Inoue, Soushin; Fukuda, Keiichi

2015-04-01

We present the rare case of a 76-year-old female with infective endocarditis (IE) caused by Candida glabrata. Immediately before developing the present infection, she developed IE with vegetation on the mitral annular calcification, which was caused by Streptococcus mitis and successfully treated with penicillin-G and gentamicin. However, her fever recurred, and she developed disseminated intravascular coagulation. Blood culture revealed C. glabrata, and echocardiography revealed new vegetation on the mitral valve. After 4 weeks of treatment with micafungin, prosthetic valve replacement was performed, followed by additional administration of micafungin for 4 weeks (total of 8 weeks). No relapse at 9 months after surgery has been observed. C. glabrata endocarditis is extremely rare and difficult to manage. Our case and review of past reported cases suggest that early diagnosis and initiation of treatment contribute to good prognosis of C. glabrata endocarditis.

Acquired Flucytosine Resistance during Combination Therapy with Caspofungin and Flucytosine for Candida glabrata Cystitis.

PubMed

Charlier, Caroline; El Sissy, Carine; Bachelier-Bassi, Sophie; Scemla, Anne; Quesne, Gilles; Sitterlé, Emilie; Legendre, Christophe; Lortholary, Olivier; Bougnoux, Marie-Elisabeth

2016-01-01

Treatment of Candida glabrata cystitis remains a therapeutic challenge, and an antifungal combination using flucytosine is one option. We describe two patients with refractory C. glabrata cystitis who failed flucytosine combined with caspofungin with early-acquired high-level resistance to flucytosine due to nonsense mutations in the FUR1 gene. Rapidly acquired flucytosine resistance with microbiological failure should discourage combination of caspofungin and flucytosine during urinary candidiasis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Haemocytes collected from experimentally infected Pacific oysters, Crassostrea gigas: Detection of ostreid herpesvirus 1 DNA, RNA, and proteins in relation with inhibition of apoptosis.

PubMed

Martenot, Claire; Gervais, Ophélie; Chollet, Bruno; Houssin, Maryline; Renault, Tristan

2017-01-01

Recent transcriptomic approaches focused on anti-viral immunity in molluscs lead to the assumption that the innate immune system, such as apoptosis, plays a crucial role against ostreid herpesvirus type 1 (OsHV-1), infecting Pacific cupped oyster, Crassostrea gigas. Apoptosis constitutes a major mechanism of anti-viral response by limiting viral spread and eliminating infected cells. In this way, an OsHV-1 challenge was performed and oysters were monitored at three times post injection to investigate viral infection and host response: 2h (early after viral injection in the adductor muscle), 24h (intermediate time), and 48h (just before first oyster mortality record). Virus infection, associated with high cumulative mortality rates (74% and 100%), was demonstrated in haemocytes by combining several detection techniques such as real-time PCR, real-time RT PCR, immunofluorescence assay, and transmission electron microscopy examination. High viral DNA amounts ranged from 5.46×104 to 3.68×105 DNA copies ng-1 of total DNA, were detected in dead oysters and an increase of viral transcripts was observed from 2, 24, and 48hpi for the five targeted OsHV-1 genes encoding three putative membrane proteins (ORFs 25, 41, and 72), a putative dUTPase (ORF 75), and a putative apoptosis inhibitor (ORF 87). Apoptosis was studied at molecular and cellular levels with an early marker (phosphatidyl-serine externalisation measured by flow cytometry and epifluorescence microscopy) and a later parameter (DNA fragmentation by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay (TUNEL)). The down-regulation of genes encoding proteins involved in the activation of the apoptotic pathway (TNF and caspase 3) and the up-regulation of genes encoding anti-apoptotic proteins (IAP-2, and Bcl-2) suggested an important anti-apoptosis phenomenon in haemocytes from OsHV-1 infected oysters at 24 and 48hpi. Additionally, more phosphatidyl-serines were externalized and more cells

Morphofunctional study of the haemocytes of the bivalve mollusc Mytilus galloprovincialis with emphasis on the endolysosomal compartment.

PubMed

Cajaraville, M P; Pal, S G

1995-10-01

In the present work the haemocytes of mussels Mytilus galloprovincialis (Mollusca, Bivalvia) have been studied by light and electron microscopy in order to describe their main morphological features and to relate these to their roles in immune defence. The haemocytes belong to two definitive differentiated types, hyalinocytes and granulocytes. The former shows the presence of several fine pseudopodial protrusions, large nucleus with clumps of dense chromatin, scant cytoplasm, a well developed Golgi apparatus, lysosomes, several mitochondria (some with characteristic inclusions), coated pits and peripherally placed membrane-bound endocytic vesicles, considerable amounts of endoplasmic reticulum and ribosomes. The granulocytes generally possess an organelle-free ectoplasmic zone, numerous membrane-delimited dense granules of various types, coated pits and vesicles, endocytic and phagocytic vesicles, multivesicular bodies, several peroxisome-like organelles, mitochondria with inclusions, scant endoplasmic reticulum and small Golgi apparatus. These cells show the presence of few lipid droplets and variable amounts of glycogen particles. Some of the substructural features of the granules are documented here to indicate their probable biogenesis, growth and relationship with the endolysosomal compartment. In addition, in vitro phagocytosis experiments demonstrate that both hyalinocytes and granulocytes uptake latex and zymosan particles, granulocytes being much more active in phagocytosis than hyalinocytes.

Chronic vulvovaginal candidiasis: characteristics of women with Candida albicans, C glabrata and no candida.

PubMed Central

Geiger, A M; Foxman, B; Sobel, J D

1995-01-01

INTRODUCTION--Although as many as 5% of all women complain of chronic vulvovaginitis, little is known about these women. They may often be misdiagnosed and the role of vaginal yeast culture in diagnosing vulvovaginal candidiasis (VVC) among them has not been clearly defined. METHODS--To address these deficiencies, we tabulated initial diagnoses among new patients and conducted a medical record-based, unmatched case-control study among women reporting a history of chronic vulvovaginitis (four or more episodes in the past year) at a vulvovaginitis specialty clinic. Clinical presentation and medical history were compared for women who had a positive vaginal yeast culture for either Candida albicans or C glabrata, or who had a negative culture. RESULTS--One-third of the women had no apparent vulvovaginal disease at their initial visit. All women reported similar symptoms, except for an increased prevalence of painful sexual intercourse in women with C albicans (chi 2 p = 0.014 versus women with C glabrata and p < 0.001 versus women with no candida). Women with C glabrata were more likely to be non-white (chi 2 p = 0.071 compared with women with C albicans) and to report an underlying medical condition (chi 2 p < or = 0.001 versus both women with C albicans and women with no candida). Physical examination was normal only in women with no candida. C albicans cases were more likely to have positive potassium hydroxide microscopy (chi 2 p = 0.016) and a pH < or = 4.5 (chi 2 p = 0.011) than were C glabrata cases. CONCLUSIONS--These results suggest that reliance on symptoms and signs alone will result in significant misdiagnosis of chronic vulvovaginitis. Among women with VVC, subtle differences in clinical presentation do not reliably distinguish women with C albicans from those with C glabrata. Our study also indicates that vaginal yeast cultures, while not necessary for every patient, are valuable in confirming negative diagnoses, detecting microscopy false-negatives, and

Proteomic analysis of hyperadhesive Candida glabrata clinical isolates reveals a core wall proteome and differential incorporation of adhesins.

PubMed

Gómez-Molero, Emilia; de Boer, Albert D; Dekker, Henk L; Moreno-Martínez, Ana; Kraneveld, Eef A; Ichsan; Chauhan, Neeraj; Weig, Michael; de Soet, Johannes J; de Koster, Chris G; Bader, Oliver; de Groot, Piet W J

2015-12-01

Attachment to human host tissues or abiotic medical devices is a key step in the development of infections by Candida glabrata. The genome of this pathogenic yeast codes for a large number of adhesins, but proteomic work using reference strains has shown incorporation of only few adhesins in the cell wall. By making inventories of the wall proteomes of hyperadhesive clinical isolates and reference strain CBS138 using mass spectrometry, we describe the cell wall proteome of C. glabrata and tested the hypothesis that hyperadhesive isolates display differential incorporation of adhesins. Two clinical strains (PEU382 and PEU427) were selected, which both were hyperadhesive to polystyrene and showed high surface hydrophobicity. Cell wall proteome analysis under biofilm-forming conditions identified a core proteome of about 20 proteins present in all C. glabrata strains. In addition, 12 adhesin-like wall proteins were identified in the hyperadherent strains, including six novel adhesins (Awp8-13) of which only Awp12 was also present in CBS138. We conclude that the hyperadhesive capacity of these two clinical C. glabrata isolates is correlated with increased and differential incorporation of cell wall adhesins. Future studies should elucidate the role of the identified proteins in the establishment of C. glabrata infections. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Failed Reverse Total Shoulder Arthroplasty Caused by Recurrent Candida glabrata Infection with Prior Serratia marcescens Coinfection

PubMed Central

Skedros, John G.; Keenan, Kendra E.; Updike, Wanda S.; Oliver, Marquam R.

2014-01-01

This report describes a 58-year-old insulin-dependent diabetic male patient who initially sustained a proximal humerus fracture from a fall. The fracture fixation failed and then was converted to a humeral hemiarthroplasty, which became infected with Candida glabrata and Serratia marcescens. After these infections were believed to be cured with antibacterial and antifungal treatments and two-stage irrigation and debridement, he underwent conversion to a reverse total shoulder arthroplasty. Unfortunately, the C. glabrata infection recurred and, nearly 1.5 years after implantation of the reverse total shoulder, he had a resection arthroplasty (removal of all implants and cement). His surgical and pharmacologic treatment concluded with (1) placement of a tobramycin-impregnated cement spacer also loaded with amphotericin B, with no plan for revision arthroplasty (i.e., the spacer was chronically retained), and (2) chronic use of daily oral fluconazole. We located only three reported cases of Candida species causing infection in shoulder arthroplasties (two C. albicans, one C. parapsilosis). To our knowledge, a total shoulder arthroplasty infected with C. glabrata has not been reported, nor has a case of a C. glabrata and S. marcescens periprosthetic coinfection in any joint. In addition, it is well known that S. marcescens infections are uncommon in periprosthetic joint infections. PMID:25431708

Fluconazole resistance in Candida glabrata.

PubMed Central

Hitchcock, C A; Pye, G W; Troke, P F; Johnson, E M; Warnock, D W

1993-01-01

We report a case of infection with Candida glabrata in which the organism became resistant to fluconazole and in which pre- and posttreatment isolates were available for comparison. The organism was cross-resistant to ketoconazole and itraconazole, in common with other azole-resistant yeasts. Fluconazole was a potent inhibitor of cytochrome P-450-dependent 14 alpha-sterol demethylase (P-450DM) in lysates of cells from both susceptible and resistant cultures (50% inhibitory concentration, 0.2 microM), indicating that resistance was unrelated to changes in P-450DM. Instead, it appeared to arise from a permeability barrier to fluconazole, since resistant cells were unable to take up radiolabelled drug. PMID:8239613

Discriminative power of fatty acid methyl ester (FAME) analysis using the microbial identification system (MIS) for Candida (Torulopsis) glabrata and Saccharomyces cerevisiae.

PubMed

Peltroche-Llacsahuanga, H; Schmidt, S; Lütticken, R; Haase, G

2000-12-01

Candida (Torulopsis) glabrata is frequently isolated in cases of fungal infection and commonly shows acquired or innate fluconazole resistance. Saccharomyces cerevisiae, an emerging opportunistic yeast pathogen, causes serious systemic infections in immunocompromised, and vaginitis and superficial infections in immunocompetent patients. For both species reliable identification in the routine laboratory is mandatory, but species identification of strains, e.g. trehalose-negative C. glabrata, may be difficult. Therefore, gas-liquid chromatography (GLC) of whole cell fatty acid methyl ester (FAME) profiles, that is independent of assimilation profiles of strains and suitable for reliable and rapid identification of clinically important yeasts, was applied. However, frequent misidentification of C. glabrata as S. cerevisiae has been reported when using the Yeast Clinical Database of MIS. Accuracy of MIS identification may be strongly influenced by the amounts of cell mass analyzed. Therefore, the present study compared the MIS results of these two yeasts achieved with different cell masses. Primarily we optimized, especially with respect to cost-effectiveness, the recommended streaking technique yielding a maximal recovery of 90-130 mg of cell mass from one plate, enabling testing of poor growing strains of C. glabrata. For all C. glabrata strains tested (n = 10) the highest identification scores (SI [Similarity Index] range 0.525-0.963, median 0.832) were achieved with 30 to 45 mg of cell mass. Only 5 of 10 S. cerevisiae strains revealed good library comparisons (SI > or = 0.5) when using 30 mg of cell mass, whereas with 45 mg all strains but two revealed this SI-level. For S. cerevisiae a higher amount of cell mass processed (up to 90 mg) was correlated with better identification scores (SI range using 90 mg: 0.464-0.870, median, 0.737). Several passages prior to FAME analysis of C. glabrata strains on recommended media revealed narrowing of SI ranges, but

Occurrence and characterization of Candida nivariensis from a culture collection of Candida glabrata clinical isolates in Malaysia.

PubMed

Tay, Sun Tee; Lotfalikhani, Azadeh; Sabet, Negar Shafiei; Ponnampalavanar, Sasheela; Sulaiman, Sofiah; Na, Shiang Ling; Ng, Kee Peng

2014-10-01

Candida nivariensis and C. bracarensis have been recently identified as emerging yeast pathogens which are phenotypically indistinguishable from C. glabrata. However, there is little data on the prevalence and antifungal susceptibilities of these species. This study investigated the occurrence of C. nivariensis and C. bracarensis in a culture collection of 185 C. glabrata isolates at a Malaysian teaching hospital. C. nivariensis was discriminated from C. glabrata using a PCR assay as described by Enache-Angoulvant et al. (J Clin Microbiol 49:3375-9, 2011). The identity of the isolates was confirmed by sequence analysis of the D1D2 domain and internal transcribed spacer region of the yeasts. The isolates were cultured on Chromogenic CHROMagar Candida (®) agar (Difco, USA), and their biochemical and enzymic profiles were determined. Antifungal susceptibilities of the isolates against amphotericin B, fluconazole, voriconazole and caspofungin were determined using E tests. Clotrimazole MICs were determined using a microbroth dilution method. There was a low prevalence (1.1 %) of C. nivariensis in our culture collection of C. glabrata. C. nivariensis was isolated from a blood culture and vaginal swab of two patients. C. nivariensis grew as white colonies on Chromogenic agar and demonstrated few positive reactions using biochemical tests. Enzymatic profiles of the C. nivariensis isolates were similar to that of C. glabrata. The isolates were susceptible to amphotericin B, fluconazole, voriconazole and caspofungin. Clotrimazole resistance is suspected in one isolate. This study reports for the first time the emergence of C. nivariensis in our clinical setting.

Portrait of Matrix Gene Expression in Candida glabrata Biofilms with Stress Induced by Different Drugs

PubMed Central

2018-01-01

(1) Background: Candida glabrata is one of the most significant Candida species associated with severe cases of candidiasis. Biofilm formation is an important feature, closely associated with antifungal resistance, involving alterations of gene expression or mutations, which can result in the failure of antifungal treatments. Hence, the main goal of this work was to evaluate the role of a set of genes, associated with matrix production, in the resistance of C. glabrata biofilms to antifungal drugs. (2) Methods: the determination of the expression of BGL2, XOG1, FKS1, FKS2, GAS2, KNH1, UGP1, and MNN2 genes in 48-h biofilm’s cells of three C. glabrata strains was performed through quantitative real-time PCR (RT-qPCR), after contact with Fluconazole (Flu), Amphotericin B (AmB), Caspofungin (Csf), or Micafungin (Mcf). (3) Results: Mcf induced a general overexpression of the selected genes. It was verified that the genes related to the production of β-1,3-glucans (BGL2, XOG1, GAS2) had the highest expressions. (4) Conclusion: though β-1,6-glucans and mannans are an essential part of the cell and biofilm matrix, C. glabrata biofilm cells seem to contribute more to the replacement of β-1,3-glucans. Thus, these biopolymers seem to have a greater impact on the biofilm matrix composition and, consequently, a role in the biofilm resistance to antifungal drugs. PMID:29642649

Molluscicidal activity of Manilkara subsericea (Mart.) dubard on Biomphalaria glabrata (Say, 1818).

PubMed

Faria, Robson Xavier; Rocha, Leandro Machado; Souza, Eloísa Portugal Barros Silva Soares; Almeida, Fernanda Borges; Fernandes, Caio Pinho; Santos, José Augusto Albuquerque

2018-02-01

Schistosomiasis is promoted for species from Schistosoma genus affecting over 200 million people worldwide. Molluscicides are an efficient method to control this disease, being able to reduce intermediate host snail Biomphalaria glabrata number. In function of resistance cases using niclosamide, natural products are promisors to discover new drugs. Manilkara subsericea is endemic to Brazilian sandbanks of Rio de Janeiro State and wide ranges of biological activities. However, there is no studies evaluating its effects as molluscicidal agent. We tested crude extract from leaves of M. subsericea molluscicidal action, as well it ethyl-acetate fraction and isolated substances against B. glabrata. M. subsericea leaves crude extract and ethyl acetate fraction induced 80±4.13% and 86.66±4.59% mortality of adult snails at concentrations of 250ppm after 96h, and their LD 50 values were 118.7±1.62 and 23.41±1.15ppm respectively. Isolated substances from M. subsericea were also considered active. Quercetin, myricetin and ursolic acid, at concentration of 100ppm (96h), were able to induce mortality levels of 100%, 80% and 53.33%, respectively. Our results suggest that M. subsericea can be considered promising as a molluscicide agent. Copyright © 2017. Published by Elsevier B.V.

Fluconazole impacts the extracellular matrix of fluconazole-susceptible and -resistant Candida albicans and Candida glabrata biofilms.

PubMed

Panariello, Beatriz Helena Dias; Klein, Marlise I; Mima, Ewerton Garcia De Oliveira; Pavarina, Ana Cláudia

2018-01-01

Background : Fluconazole (FLZ) is a drug commonly used for the treatment of Candida infections. However, β-glucans in the extracellular matrices (ECMs) hinder FLZ penetration into Candida biofilms, while extracellular DNA (eDNA) contributes to the biofilm architecture and resistance. Methods : This study characterized biofilms of FLZ-sensitive (S) and -resistant (R) Candida albicans and Candida glabrata in the presence or absence of FLZ focusing on the ECM traits. Biofilms of C. albicans American Type Culture Collection (ATCC) 90028 (CaS), C. albicans ATCC 96901 (CaR), C. glabrata ATCC 2001 (CgS), and C. glabrata ATCC 200918 (CgR) were grown in RPMI medium with or without FLZ at 5× the minimum inhibitory concentration (37°C/48 h). Biofilms were assessed by colony-forming unit (CFU)/mL, biomass, and ECM components (alkali-soluble polysaccharides [ASP], water-soluble polysaccharides [WSP], eDNA, and proteins). Scanning electron microscopy (SEM) was also performed. Data were analyzed by parametric and nonparametric tests ( α   =  0.05). Results : In biofilms, FLZ reduced the CFU/mL of all strains ( p  < 0.001), except for CaS ( p  = 0.937). However, the ASP quantity in CaS was significantly reduced by FLZ ( p  = 0.034), while the drug had no effect on the ASP levels in other strains ( p  > 0.05). Total biomasses and WSP were significantly reduced by FLZ in the ECM of all yeasts ( p  < 0.001), but levels of eDNA and proteins were unaffected ( p  > 0.05). FLZ affected the cell morphology and biofilm structure by hindering hyphae formation in CaS and CaR biofilms, by decreasing the number of cells in CgS and CgR biofilms, and by yielding sparsely spaced cell agglomerates on the substrate. Conclusion : FLZ impacts biofilms of C. albicans and C. glabrata as evident by reduced biomass. This reduced biomass coincided with lowered cell numbers and quantity of WSPs. Hyphal production by C. albicans was also reduced.

A Drosophila haemocyte-specific protein, hemolectin, similar to human von Willebrand factor.

PubMed Central

Goto, A; Kumagai, T; Kumagai, C; Hirose, J; Narita, H; Mori, H; Kadowaki, T; Beck, K; Kitagawa, Y

2001-01-01

We identified a novel Drosophila protein of approximately 400 kDa, hemolectin (d-Hml), secreted from haemocyte-derived Kc167 cells. Its 11.7 kbp cDNA contains an open reading frame of 3843 amino acid residues, with conserved domains in von Willebrand factor (VWF), coagulation factor V/VIII and complement factors. The d-hml gene is located on the third chromosome (position 70C1-5) and consists of 26 exons. The major part of d-Hml consists of well-known motifs with the organization: CP1-EG1-CP2-EG2-CP3-VD1-VD2-VD'-VD3-VC1-VD"-VD"'-FC1-FC2-VC2-LA1-VD4-VD5-VC3-VB1-VB2-VC4-VC5-CK1 (CP, complement-control protein domain; EG, epidermal-growth-factor-like domain; VB, VC, VD, VWF type B-, C- and D-like domains; VD', VD", VD"', truncated C-terminal VDs; FC, coagulation factor V/VIII type C domain; LA, low-density-lipoprotein-receptor class A domain; CK, cysteine knot domain). The organization of VD1-VD2-VD'-VD3, essential for VWF to be processed by furin, to bind to coagulation factor VIII and to form interchain disulphide linkages, is conserved. The 400 kDa form of d-Hml was sensitive to acidic cleavage near the boundary between VD2 and VD', where the cleavage site of pro-VWF is located. Agarose-gel electrophoresis of metabolically radiolabelled d-Hml suggested that it is secreted from Kc167 cells mainly as dimers. Resembling VWF, 7.9% (305 residues) of cysteine residues on the d-Hml sequence had well-conserved positions in each motif. Coinciding with the development of phagocytic haemocytes, d-hml transcript was detected in late embryos and larvae. Its low-level expression in adult flies was induced by injury at any position on the body. PMID:11563973

New insights into the amphibious life of Biomphalaria glabrata and susceptibility of its egg masses to fungal infection.

PubMed

Duarte, Glennyha F; Rodrigues, Juscelino; Fernandes, Éverton K K; Humber, Richard A; Luz, Christian

2015-02-01

The air-breathing snail Biomphalaria glabrata proliferates in stagnant freshwater, and nothing is known about the survival of eggs in intermittently (rather than perpetually) wet habitats. In the present study their egg masses matured, and juveniles subsequently eclosed and were mobile in a stable water film of transitory habitats simulated by two different simple test devices described here. The viability of eggs maintained in an unstable film however, was diminished. The maturation of egg masses in a water film or in water was significantly prevented by the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae. The efficiency depended on the fungal propagule and test environment. Hyphal bodies were more effective against egg masses than conidia. This appears to be a first report of activity of either entomopathogen against a mollusc. Both devices offer accurate and reproducible conditions to test both biological questions and the effects of substances or pathogens against B. glabrata egg masses in water films. Copyright © 2015 Elsevier Inc. All rights reserved.

Production of White Colonies on CHROMagar Candida Medium by Members of the Candida glabrata Clade and Other Species with Overlapping Phenotypic Traits▿

PubMed Central

Bishop, Justin A.; Chase, Nancy; Lee, Richard; Kurtzman, Cletus P.; Merz, William G.

2008-01-01

We hypothesized that species of the Candida glabrata clade and species with phenotypic traits that overlap those of C. glabrata would produce white colonies on CHROMagar Candida medium. Of 154 isolates (seven species) tested, C. bracarensis, C. nivariensis, C. norvegensis, C. glabrata, and C. inconspicua produced white colonies; the Pichia fermentans group and C. krusei did not. Many of these species are difficult to identify phenotypically; white colonies may signal the need for the use of molecular approaches. PMID:18685009

Segregation and transmission of mitochondrial markers in fusion products of the asporogenous yeast Torulopsis glabrata.

PubMed

Sriprakash, K S; Batum, C

1981-09-01

Using a protoplast fusion technique we have been able to locate to the mitochondrial genome of the asporogenous yeast Torulopsis glabrata mutations conferring resistance to oligomycin, antimycin and diuron. When two strains differing in the size of their mtDNAs were fused the mitochondrial markers from the parent with the larger mtDNA (71-91) were transmitted predominantly among the fusion products. Both genetical and physical evidence support the occurrence of recombination in T. glabrata mitochondrial genome. Segregation of the mitochondrial genome appears to take place before the separation of the first bud from the fusion product.

[Quantitative determination of biogenic amine from Biomphalaria glabrata nervous system by UPLC MS/MS].

PubMed

Tao, Huang; Yun-Hai, Guo; He-Xiang, Liu; Yi, Zhang

2018-04-19

To establish a method for the quantitative determination of serotonin and dopamine in the nervous system of Biomphalaria glabrata by using ultra high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC MS/MS) . The B. glabrata nervous system was broken in the pure methanol solution after obtaining it by dissecting with microscope. Then, the supernatant containing the target substance after twice high speed centrifugation was got. The extraction was separated on an ACQUITY UPLC BEH Amide column with Waters TQ-XS series mass spectrometry detector, with ESI source and positive electrospray ionization mode when the machine testing. The detection limit of serotonin was 0.03 ng/ml and the limit of quantification was 0.1 ng/ml. The detection limit of dopamine was 0.05 ng/ml and the limit of quantification was 0.15 ng/ml. The recoveries of serotonin ranged from 90.68% to 94.72% over the range of 1 to 40 ng/ml. The recoveries of dopamine ranged from 91.68% to 96.12% over the range of 1.0 ng/ml to 40 ng/ml. The established UPLC MS/MS method is simple, stable and reproducible. It can be used for the quantitative analysis of serotonin and dopamine in the nervous system of B. glabrata snails.

Steroid Androgen Exposure during Development Has No Effect on Reproductive Physiology of Biomphalaria glabrata.

PubMed

Kaur, Satwant; Baynes, Alice; Lockyer, Anne E; Routledge, Edwin J; Jones, Catherine S; Noble, Leslie R; Jobling, Susan

2016-01-01

Gastropod mollusks have been proposed as alternative models for male reproductive toxicity testing, due to similarities in their reproductive anatomy compared to mammals, together with evidence that endocrine disrupting chemicals can cause effects in some mollusks analogous to those seen in mammals. To test this hypothesis, we used the freshwater pulmonate snail, Biomphalaria glabrata, for which various genetic tools and a draft genome have recently become available, to investigate the effects of two steroid androgens on the development of mollusk secondary sexual organs. Here we present the results of exposures to two potent androgens, the vertebrate steroid; 5α-dihydrotestosterone (DHT) and the pharmaceutical anabolic steroid; 17α-methyltestosterone (MT), under continuous flow-through conditions throughout embryonic development and up to sexual maturity. Secondary sexual gland morphology, histopathology and differential gene expression analysis were used to determine whether steroid androgens stimulated or inhibited organ development. No significant differences between tissues from control and exposed snails were identified, suggesting that these androgens elicited no biologically detectable response normally associated with exposure to androgens in vertebrate model systems. Identifying no effect of androgens in this mollusk is significant, not only in the context of the suitability of mollusks as alternative model organisms for testing vertebrate androgen receptor agonists but also, if applicable to other similar mollusks, in terms of the likely impacts of androgens and anti-androgenic pollutants present in the aquatic environment.

Competitive Interactions between C. albicans, C. glabrata and C. krusei during Biofilm Formation and Development of Experimental Candidiasis.

PubMed

Rossoni, Rodnei Dennis; Barbosa, Júnia Oliveira; Vilela, Simone Furgeri Godinho; dos Santos, Jéssica Diane; de Barros, Patrícia Pimentel; Prata, Márcia Cristina de Azevedo; Anbinder, Ana Lia; Fuchs, Beth Burgwyn; Jorge, Antonio Olavo Cardoso; Mylonakis, Eleftherios; Junqueira, Juliana Campos

2015-01-01

In this study, we evaluated the interactions between Candida albicans, Candida krusei and Candida glabrata in mixed infections. Initially, these interactions were studied in biofilms formed in vitro. CFU/mL values of C. albicans were lower in mixed biofilms when compared to the single biofilms, verifying 77% and 89% of C. albicans reduction when this species was associated with C. glabrata and C. krusei, respectively. After that, we expanded this study for in vivo host models of experimental candidiasis. G. mellonella larvae were inoculated with monotypic and heterotypic Candida suspensions for analysis of survival rate and quantification of fungal cells in the haemolymph. In the groups with single infections, 100% of the larvae died within 18 h after infection with C. albicans. However, interaction groups achieved 100% mortality after 72 h of infection by C. albicans-C. glabrata and 96 h of infection by C. albicans-C. krusei. C. albicans CFU/mL values from larvae hemolymph were lower in the interacting groups compared with the monoespecies group after 12 h of infection. In addition, immunosuppressed mice were also inoculated with monotypic and heterotypic microbial suspensions to induce oral candidiasis. C. albicans CFU/mL values recovered from oral cavity of mice were higher in the group with single infection by C. albicans than the groups with mixed infections by C. albicans-C. glabrata and C. albicans-C. krusei. Moreover, the group with single infection by C. albicans had a higher degree of hyphae and epithelial changes in the tongue dorsum than the groups with mixed infections. We concluded that single infections by C. albicans were more harmful for animal models than mixed infections with non-albicans species, suggesting that C. albicans establish competitive interactions with C. krusei and C. glabrata during biofilm formation and development of experimental candidiasis.

Competitive Interactions between C. albicans, C. glabrata and C. krusei during Biofilm Formation and Development of Experimental Candidiasis

PubMed Central

Rossoni, Rodnei Dennis; Barbosa, Júnia Oliveira; Vilela, Simone Furgeri Godinho; dos Santos, Jéssica Diane; de Barros, Patrícia Pimentel; Prata, Márcia Cristina de Azevedo; Anbinder, Ana Lia; Fuchs, Beth Burgwyn; Jorge, Antonio Olavo Cardoso; Mylonakis, Eleftherios; Junqueira, Juliana Campos

2015-01-01

In this study, we evaluated the interactions between Candida albicans, Candida krusei and Candida glabrata in mixed infections. Initially, these interactions were studied in biofilms formed in vitro. CFU/mL values of C. albicans were lower in mixed biofilms when compared to the single biofilms, verifying 77% and 89% of C. albicans reduction when this species was associated with C. glabrata and C. krusei, respectively. After that, we expanded this study for in vivo host models of experimental candidiasis. G. mellonella larvae were inoculated with monotypic and heterotypic Candida suspensions for analysis of survival rate and quantification of fungal cells in the haemolymph. In the groups with single infections, 100% of the larvae died within 18 h after infection with C. albicans. However, interaction groups achieved 100% mortality after 72 h of infection by C. albicans-C. glabrata and 96 h of infection by C. albicans-C. krusei. C. albicans CFU/mL values from larvae hemolymph were lower in the interacting groups compared with the monoespecies group after 12 h of infection. In addition, immunosuppressed mice were also inoculated with monotypic and heterotypic microbial suspensions to induce oral candidiasis. C. albicans CFU/mL values recovered from oral cavity of mice were higher in the group with single infection by C. albicans than the groups with mixed infections by C. albicans-C. glabrata and C. albicans-C. krusei. Moreover, the group with single infection by C. albicans had a higher degree of hyphae and epithelial changes in the tongue dorsum than the groups with mixed infections. We concluded that single infections by C. albicans were more harmful for animal models than mixed infections with non-albicans species, suggesting that C. albicans establish competitive interactions with C. krusei and C. glabrata during biofilm formation and development of experimental candidiasis. PMID:26146832

Med15B Regulates Acid Stress Response and Tolerance in Candida glabrata by Altering Membrane Lipid Composition

PubMed Central

Qi, Yanli; Liu, Hui; Yu, Jiayin; Chen, Xiulai

2017-01-01

ABSTRACT Candida glabrata is a promising producer of organic acids. To elucidate the physiological function of the Mediator tail subunit Med15B in the response to low-pH stress, we constructed a deletion strain, C. glabrata med15BΔ, and an overexpression strain, C. glabrata HTUΔ/CgMED15B. Deletion of MED15B caused biomass production, glucose consumption rate, and cell viability to decrease by 28.3%, 31.7%, and 26.5%, respectively, compared with those of the parent (HTUΔ) strain at pH 2.0. Expression of lipid metabolism-related genes was significantly downregulated in the med15BΔ strain, whereas key genes of ergosterol biosynthesis showed abnormal upregulation. This caused the proportion of C18:1 fatty acids, the ratio of unsaturated to saturated fatty acids (UFA/SFA), and the total phospholipid content to decrease by 11.6%, 27.4%, and 37.6%, respectively. Cells failed to synthesize fecosterol and ergosterol, leading to the accumulation and a 60.3-fold increase in the concentration of zymosterol. Additionally, cells showed reductions of 69.2%, 11.6%, and 21.8% in membrane integrity, fluidity, and H+-ATPase activity, respectively. In contrast, overexpression of Med15B increased the C18:1 levels, total phospholipids, ergosterol content, and UFA/SFA by 18.6%, 143.5%, 94.5%, and 18.7%, respectively. Membrane integrity, fluidity, and H+-ATPase activity also increased by 30.2%, 6.9%, and 51.8%, respectively. Furthermore, in the absence of pH buffering, dry weight of cells and pyruvate concentrations were 29.3% and 61.2% higher, respectively, than those of the parent strain. These results indicated that in C. glabrata, Med15B regulates tolerance toward low pH via transcriptional regulation of acid stress response genes and alteration in lipid composition. IMPORTANCE This study explored the role of the Mediator tail subunit Med15B in the metabolism of Candida glabrata under acidic conditions. Overexpression of MED15B enhanced yeast tolerance to low pH and improved

Variability of haemocyte and haemolymph parameters in European flat oyster Ostrea edulis families obtained from brood stocks of different geographical origins and relation with infection by the protozoan Bonamia ostreae.

PubMed

Mirella da Silva, Patricia; Comesaña, Pilar; Fuentes, José; Villalba, Antonio

2008-05-01

A research project to compare productive traits (growth and mortality), disease susceptibility and immune capability between Ostrea edulis stocks was performed. This article reports the results on the immune capability and its relation with infection by the intrahaemocytic protozoan Bonamia ostreae. Four to five oyster spat families were produced from each of four European flat oyster populations (one from Ireland, one from Greece and two from Galicia, Spain) in a hatchery. The spat were transferred to a raft in the Ría de Arousa (Galicia) for on growing for 2 years. Total haemocyte count (THC) and differential haemocyte count (DHC) were estimated monthly through the second year of growing-out. Three types of haemocytes were distinguished: granulocytes (GH), large hyalinocytes (LHH) and small hyalinocytes (SHH). Significant correlations between the mean relative abundance of GH and SHH of the families and the mean prevalence of B. ostreae, the overall incidence of pathological conditions and the cumulative mortality of the families were found; these correlations supported the hypothesis that high %GH and low %SHH would enhance oyster immune ability and, consequently, would contribute to lower susceptibility to disease and longer lifespan. Infection by B. ostreae involved a significant increase of circulating haemocytes, which affected more markedly the LHH type. The higher the infection intensity the higher the %LHH. This illustrates the ability of B. ostreae to modulate the immune responses of the O. edulis to favour its own multiplication. A significant reduction of the phenoloxidase activity in the haemolymph of oysters O. edulis infected by B. ostreae was observed. Nineteen enzymatic activities in the haemolymph of O. edulis and Crassostrea gigas (used as a B. ostreae resistant reference) were measured using the kit api ZYM, Biomerieux. Qualitative and quantitative differences in enzyme activities in both haemocyte and plasma fractions between B. ostreae

Construction of an Ostrea edulis database from genomic and expressed sequence tags (ESTs) obtained from Bonamia ostreae infected haemocytes: Development of an immune-enriched oligo-microarray.

PubMed

Pardo, Belén G; Álvarez-Dios, José Antonio; Cao, Asunción; Ramilo, Andrea; Gómez-Tato, Antonio; Planas, Josep V; Villalba, Antonio; Martínez, Paulino

2016-12-01

The flat oyster, Ostrea edulis, is one of the main farmed oysters, not only in Europe but also in the United States and Canada. Bonamiosis due to the parasite Bonamia ostreae has been associated with high mortality episodes in this species. This parasite is an intracellular protozoan that infects haemocytes, the main cells involved in oyster defence. Due to the economical and ecological importance of flat oyster, genomic data are badly needed for genetic improvement of the species, but they are still very scarce. The objective of this study is to develop a sequence database, OedulisDB, with new genomic and transcriptomic resources, providing new data and convenient tools to improve our knowledge of the oyster's immune mechanisms. Transcriptomic and genomic sequences were obtained using 454 pyrosequencing and compiled into an O. edulis database, OedulisDB, consisting of two sets of 10,318 and 7159 unique sequences that represent the oyster's genome (WG) and de novo haemocyte transcriptome (HT), respectively. The flat oyster transcriptome was obtained from two strains (naïve and tolerant) challenged with B. ostreae, and from their corresponding non-challenged controls. Approximately 78.5% of 5619 HT unique sequences were successfully annotated by Blast search using public databases. A total of 984 sequences were identified as being related to immune response and several key immune genes were identified for the first time in flat oyster. Additionally, transcriptome information was used to design and validate the first oligo-microarray in flat oyster enriched with immune sequences from haemocytes. Our transcriptomic and genomic sequencing and subsequent annotation have largely increased the scarce resources available for this economically important species and have enabled us to develop an OedulisDB database and accompanying tools for gene expression analysis. This study represents the first attempt to characterize in depth the O. edulis haemocyte transcriptome in

Schistosomiasis Control Using Piplartine against Biomphalaria glabrata at Different Developmental Stages

PubMed Central

Rapado, Ludmila Nakamura; Pinheiro, Alessandro de Sá; Lopes, Priscila Orechio de Moraes Victor; Fokoue, Harold Hilarion; Scotti, Marcus Tullius; Marques, Joaquim Vogt; Ohlweiler, Fernanda Pires; Borrely, Sueli Ivone; Pereira, Carlos Alberto de Bragança; Kato, Massuo Jorge; Nakano, Eliana; Yamaguchi, Lydia Fumiko

2013-01-01

Background Schistosomiasis is one of the most significant diseases in tropical countries and affects almost 200 million people worldwide. The application of molluscicides to eliminate the parasite's intermediate host, Biomphalaria glabrata, from infected water supplies is one strategy currently being used to control the disease. Previous studies have shown a potent molluscicidal activity of crude extracts from Piper species, with extracts from Piper tuberculatum being among the most active. Methods and Findings The molluscicidal activity of P. tuberculatum was monitored on methanolic extracts from different organs (roots, leaves, fruit and stems). The compounds responsible for the molluscicidal activity were identified using 1H NMR and ESIMS data and multivariate analyses, including principal component analysis and partial least squares. These results indicated that the high molluscicidal activity displayed by root extracts (LC50 20.28 µg/ml) was due to the presence of piplartine, a well-known biologically-active amide. Piplartine was isolated from P. tuberculatum root extracts, and the molluscicidal activity of this compound on adults and embryos of B. glabrata was determined. The compound displayed potent activity against all developmental stages of B. glabrata. Next, the environmental toxicity of piplartine was evaluated using the microcrustacean Daphnia similis (LC50 7.32 µg/ml) and the fish Danio rerio (1.69 µg/ml). The toxicity to these organisms was less compared with the toxicity of niclosamide, a commercial molluscicide. Conclusions The development of a new, natural molluscicide is highly desirable, particularly because the commercially available molluscicide niclosamide is highly toxic to some organisms in the environment (LC50 0.25 µg/ml to D. similis and 0.12 µg/ml to D. rerio). Thus, piplartine is a potential candidate for a natural molluscicide that has been extracted from a tropical plant species and showed less toxic to environment. PMID

Ionotropic Receptors Identified within the Tentacle of the Freshwater Snail Biomphalaria glabrata, an Intermediate Host of Schistosoma mansoni

PubMed Central

Liang, Di; Wang, Tianfang; Rotgans, Bronwyn A.; McManus, Donald P.; Cummins, Scott F.

2016-01-01

Biomphalaria glabrata (B. glabrata) is an air-breathing aquatic mollusc found in freshwater habitats across the Western Hemisphere. It is most well-known for its recognized capacity to act as a major intermediate host for Schistosoma mansoni, the human blood fluke parasite. Ionotropic receptors (IRs), a variant family of the ionotropic glutamate receptors (iGluR), have an evolutionary ancient function in detecting odors to initiate chemosensory signaling. In this study, we applied an array of methods towards the goal of identifying IR-like family members in B. glabrata, ultimately revealing two types, the iGluR and IR. Sequence alignment showed that three ligand-binding residues are conserved in most Biomphalaria iGluR sequences, while the IRs did exhibit a variable pattern, lacking some or all known glutamate-interactingresidues, supporting their distinct classification from the iGluRs. We show that B. glabrata contains 7 putative IRs, some of which are expressed within its chemosensory organs. To further investigate a role for the more ancient IR25a type in chemoreception, we tested its spatial distribution pattern within the snail cephalic tentacle by in situ hybridization. The presence of IR25a within presumptive sensory neurons supports a role for this receptor in olfactory processing, contributing to our understanding of the molecular pathways that are involved in Biomphalaria olfactory processing. PMID:27253696

Ionotropic Receptors Identified within the Tentacle of the Freshwater Snail Biomphalaria glabrata, an Intermediate Host of Schistosoma mansoni.

PubMed

Liang, Di; Wang, Tianfang; Rotgans, Bronwyn A; McManus, Donald P; Cummins, Scott F

2016-01-01

Biomphalaria glabrata (B. glabrata) is an air-breathing aquatic mollusc found in freshwater habitats across the Western Hemisphere. It is most well-known for its recognized capacity to act as a major intermediate host for Schistosoma mansoni, the human blood fluke parasite. Ionotropic receptors (IRs), a variant family of the ionotropic glutamate receptors (iGluR), have an evolutionary ancient function in detecting odors to initiate chemosensory signaling. In this study, we applied an array of methods towards the goal of identifying IR-like family members in B. glabrata, ultimately revealing two types, the iGluR and IR. Sequence alignment showed that three ligand-binding residues are conserved in most Biomphalaria iGluR sequences, while the IRs did exhibit a variable pattern, lacking some or all known glutamate-interactingresidues, supporting their distinct classification from the iGluRs. We show that B. glabrata contains 7 putative IRs, some of which are expressed within its chemosensory organs. To further investigate a role for the more ancient IR25a type in chemoreception, we tested its spatial distribution pattern within the snail cephalic tentacle by in situ hybridization. The presence of IR25a within presumptive sensory neurons supports a role for this receptor in olfactory processing, contributing to our understanding of the molecular pathways that are involved in Biomphalaria olfactory processing.

Long-term affected flat oyster (Ostrea edulis) haemocytes show differential gene expression profiles from naïve oysters in response to Bonamia ostreae.

PubMed

Ronza, P; Cao, A; Robledo, D; Gómez-Tato, A; Álvarez-Dios, J A; Hasanuzzaman, A F M; Quiroga, M I; Villalba, A; Pardo, B G; Martínez, P

2018-04-18

European flat oyster (Ostrea edulis) production has suffered a severe decline due to bonamiosis. The responsible parasite enters in oyster haemocytes, causing an acute inflammatory response frequently leading to death. We used an immune-enriched oligo-microarray to understand the haemocyte response to Bonamia ostreae by comparing expression profiles between naïve (NS) and long-term affected (AS) populations along a time series (1 d, 30 d, 90 d). AS showed a much higher response just after challenge, which might be indicative of selection for resistance. No regulated genes were detected at 30 d in both populations while a notable reactivation was observed at 90 d, suggesting parasite latency during infection. Genes related to extracellular matrix and protease inhibitors, up-regulated in AS, and those related to histones, down-regulated in NS, might play an important role along the infection. Twenty-four candidate genes related to resistance should be further validated for selection programs aimed to control bonamiosis. Copyright © 2018 Elsevier Inc. All rights reserved.

Aspartyl proteases in Candida glabrata are required for suppression of the host innate immune response.

PubMed

Rasheed, Mubashshir; Battu, Anamika; Kaur, Rupinder

2018-04-27

A family of 11 cell surface-associated aspartyl proteases (CgYps1-11), also referred as yapsins, is a key virulence factor in the pathogenic yeast Candida glabrata However, the mechanism by which CgYapsins modulate immune response and facilitate survival in the mammalian host remains to be identified. Here, using RNA-Seq analysis, we report that genes involved in cell wall metabolism are differentially regulated in the Cgyps1-11 Δ mutant. Consistently, the mutant contained lower β-glucan and mannan levels and exhibited increased chitin content in the cell wall. As cell wall components are known to regulate the innate immune response, we next determined the macrophage transcriptional response to C. glabrata infection and observed differential expression of genes implicated in inflammation, chemotaxis, ion transport, and the tumor necrosis factor signaling cascade. Importantly, the Cgyps1-11 Δ mutant evoked a different immune response, resulting in an enhanced release of the pro-inflammatory cytokine IL-1β in THP-1 macrophages. Further, Cgyps1-11 Δ-induced IL-1β production adversely affected intracellular proliferation of co-infected WT cells and depended on activation of spleen tyrosine kinase (Syk) signaling in the host cells. Accordingly, the Syk inhibitor R406 augmented intracellular survival of the Cgyps1-11 Δ mutant. Finally, we demonstrate that C. glabrata infection triggers elevated IL-1β production in mouse organs and that the CgYPS genes are required for organ colonization and dissemination in the murine model of systemic infection. Altogether, our results uncover the basis for macrophage-mediated killing of Cgyps1-11 Δ cells and provide the first evidence that aspartyl proteases in C. glabrata are required for suppression of IL-1β production in macrophages. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Aspartyl proteases in Candida glabrata are required for suppression of the host innate immune response

PubMed Central

Rasheed, Mubashshir; Battu, Anamika; Kaur, Rupinder

2018-01-01

A family of 11 cell surface-associated aspartyl proteases (CgYps1–11), also referred as yapsins, is a key virulence factor in the pathogenic yeast Candida glabrata. However, the mechanism by which CgYapsins modulate immune response and facilitate survival in the mammalian host remains to be identified. Here, using RNA-Seq analysis, we report that genes involved in cell wall metabolism are differentially regulated in the Cgyps1–11Δ mutant. Consistently, the mutant contained lower β-glucan and mannan levels and exhibited increased chitin content in the cell wall. As cell wall components are known to regulate the innate immune response, we next determined the macrophage transcriptional response to C. glabrata infection and observed differential expression of genes implicated in inflammation, chemotaxis, ion transport, and the tumor necrosis factor signaling cascade. Importantly, the Cgyps1–11Δ mutant evoked a different immune response, resulting in an enhanced release of the pro-inflammatory cytokine IL-1β in THP-1 macrophages. Further, Cgyps1–11Δ–induced IL-1β production adversely affected intracellular proliferation of co-infected WT cells and depended on activation of spleen tyrosine kinase (Syk) signaling in the host cells. Accordingly, the Syk inhibitor R406 augmented intracellular survival of the Cgyps1–11Δ mutant. Finally, we demonstrate that C. glabrata infection triggers elevated IL-1β production in mouse organs and that the CgYPS genes are required for organ colonization and dissemination in the murine model of systemic infection. Altogether, our results uncover the basis for macrophage-mediated killing of Cgyps1–11Δ cells and provide the first evidence that aspartyl proteases in C. glabrata are required for suppression of IL-1β production in macrophages. PMID:29491142

Reversing the Resistance Phenotype of the Biomphalaria glabrata Snail Host Schistosoma mansoni Infection by Temperature Modulation

PubMed Central

Ittiprasert, Wannaporn; Knight, Matty

2012-01-01

Biomphalaria glabrata snails that display either resistant or susceptible phenotypes to the parasitic trematode, Schistosoma mansoni provide an invaluable resource towards elucidating the molecular basis of the snail-host/schistosome relationship. Previously, we showed that induction of stress genes either after heat-shock or parasite infection was a major feature distinguishing juvenile susceptible snails from their resistant counterparts. In order to examine this apparent association between heat stress and snail susceptibility, we investigated the effect of temperature modulation in the resistant snail stock, BS-90. Here, we show that, incubated for up to 4 hrs at 32°C prior to infection, these resistant snails became susceptible to infection, i.e. shedding cercariae at 5 weeks post exposure (PE) while unstressed resistant snails, as expected, remained resistant. This suggests that susceptibility to infection by this resistant snail phenotype is temperature-sensitive (ts). Additionally, resistant snails treated with the Hsp 90 specific inhibitor, geldanamycin (GA) after heat stress, were no longer susceptible to infection, retaining their resistant phenotype. Consistently, susceptible snail phenotypes treated with 100 mM GA before parasite exposure also remained uninfected. These results provide direct evidence for the induction of stress genes (heat shock proteins; Hsp 70, Hsp 90 and the reverse transcriptase [RT] domain of the nimbus non-LTR retrotransposon) in B. glabrata susceptibility to S. mansoni infection and characterize the resistant BS-90 snails as a temperature-sensitive phenotype. This study of reversing snail susceptibility phenotypes to S. mansoni provides an opportunity to directly track molecular pathway(s) that underlie the B. glabrata snail's ability to either sustain or destroy the S. mansoni parasite. PMID:22577362

Reversing the resistance phenotype of the Biomphalaria glabrata snail host Schistosoma mansoni infection by temperature modulation.

PubMed

Ittiprasert, Wannaporn; Knight, Matty

2012-01-01

Biomphalaria glabrata snails that display either resistant or susceptible phenotypes to the parasitic trematode, Schistosoma mansoni provide an invaluable resource towards elucidating the molecular basis of the snail-host/schistosome relationship. Previously, we showed that induction of stress genes either after heat-shock or parasite infection was a major feature distinguishing juvenile susceptible snails from their resistant counterparts. In order to examine this apparent association between heat stress and snail susceptibility, we investigated the effect of temperature modulation in the resistant snail stock, BS-90. Here, we show that, incubated for up to 4 hrs at 32°C prior to infection, these resistant snails became susceptible to infection, i.e. shedding cercariae at 5 weeks post exposure (PE) while unstressed resistant snails, as expected, remained resistant. This suggests that susceptibility to infection by this resistant snail phenotype is temperature-sensitive (ts). Additionally, resistant snails treated with the Hsp 90 specific inhibitor, geldanamycin (GA) after heat stress, were no longer susceptible to infection, retaining their resistant phenotype. Consistently, susceptible snail phenotypes treated with 100 mM GA before parasite exposure also remained uninfected. These results provide direct evidence for the induction of stress genes (heat shock proteins; Hsp 70, Hsp 90 and the reverse transcriptase [RT] domain of the nimbus non-LTR retrotransposon) in B. glabrata susceptibility to S. mansoni infection and characterize the resistant BS-90 snails as a temperature-sensitive phenotype. This study of reversing snail susceptibility phenotypes to S. mansoni provides an opportunity to directly track molecular pathway(s) that underlie the B. glabrata snail's ability to either sustain or destroy the S. mansoni parasite.

A galectin from Eriocheir sinensis functions as pattern recognition receptor enhancing microbe agglutination and haemocytes encapsulation.

PubMed

Wang, Mengqiang; Wang, Lingling; Huang, Mengmeng; Yi, Qilin; Guo, Ying; Gai, Yunchao; Wang, Hao; Zhang, Huan; Song, Linsheng

2016-08-01

Galectins are a family of β-galactoside binding lectins that function as pattern recognition receptors (PRRs) in innate immune system of both vertebrates and invertebrates. The cDNA of Chinese mitten crab Eriocheir sinensis galectin (designated as EsGal) was cloned via rapid amplification of cDNA ends (RACE) technique based on expressed sequence tags (ESTs) analysis. The full-length cDNA of EsGal was 999 bp. Its open reading frame encoded a polypeptide of 218 amino acids containing a GLECT/Gal-bind_lectin domain and a proline/glycine rich low complexity region. The deduced amino acid sequence and domain organization of EsGal were highly similar to those of crustacean galectins. The mRNA transcripts of EsGal were found to be constitutively expressed in a wide range of tissues and mainly in hepatopancreas, gill and haemocytes. The mRNA expression level of EsGal increased rapidly and significantly after crabs were stimulated by different microbes. The recombinant EsGal (rEsGal) could bind various pathogen-associated molecular patterns (PAMPs), including lipopolysaccharide (LPS), peptidoglycan (PGN) and glucan (GLU), and exhibited strong activity to agglutinate Escherichia coli, Vibrio anguillarum, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus and Pichia pastoris, and such agglutinating activity could be inhibited by both d-galactose and α-lactose. The in vitro encapsulation assay revealed that rEsGal could enhance the encapsulation of haemocytes towards agarose beads. These results collectively suggested that EsGal played crucial roles in the immune recognition and elimination of pathogens and contributed to the innate immune response against various microbes in crabs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Steroid Androgen Exposure during Development Has No Effect on Reproductive Physiology of Biomphalaria glabrata

PubMed Central

Lockyer, Anne E.; Routledge, Edwin J.; Jones, Catherine S.; Noble, Leslie R.; Jobling, Susan

2016-01-01

Gastropod mollusks have been proposed as alternative models for male reproductive toxicity testing, due to similarities in their reproductive anatomy compared to mammals, together with evidence that endocrine disrupting chemicals can cause effects in some mollusks analogous to those seen in mammals. To test this hypothesis, we used the freshwater pulmonate snail, Biomphalaria glabrata, for which various genetic tools and a draft genome have recently become available, to investigate the effects of two steroid androgens on the development of mollusk secondary sexual organs. Here we present the results of exposures to two potent androgens, the vertebrate steroid; 5α-dihydrotestosterone (DHT) and the pharmaceutical anabolic steroid; 17α-methyltestosterone (MT), under continuous flow-through conditions throughout embryonic development and up to sexual maturity. Secondary sexual gland morphology, histopathology and differential gene expression analysis were used to determine whether steroid androgens stimulated or inhibited organ development. No significant differences between tissues from control and exposed snails were identified, suggesting that these androgens elicited no biologically detectable response normally associated with exposure to androgens in vertebrate model systems. Identifying no effect of androgens in this mollusk is significant, not only in the context of the suitability of mollusks as alternative model organisms for testing vertebrate androgen receptor agonists but also, if applicable to other similar mollusks, in terms of the likely impacts of androgens and anti-androgenic pollutants present in the aquatic environment. PMID:27448327

Regulation of the CgPdr1 Transcription Factor from the Pathogen Candida glabrata ▿

PubMed Central

Paul, Sanjoy; Schmidt, Jennifer A.; Moye-Rowley, W. Scott

2011-01-01

Candida glabrata is an opportunistic human pathogen that is increasingly associated with candidemia, owing in part to the intrinsic and acquired high tolerance the organism exhibits for the important clinical antifungal drug fluconazole. This elevated fluconazole resistance often develops through gain-of-function mutations in the zinc cluster-containing transcriptional regulator C. glabrata Pdr1 (CgPdr1). CgPdr1 induces the expression of an ATP-binding cassette (ABC) transporter-encoding gene, CgCDR1. Saccharomyces cerevisiae has two CgPdr1 homologues called ScPdr1 and ScPdr3. These factors control the expression of an ABC transporter-encoding gene called ScPDR5, which encodes a homologue of CgCDR1. Loss of the mitochondrial genome (ρ0 cell) or overexpression of the mitochondrial enzyme ScPsd1 induces ScPDR5 expression in a strictly ScPdr3-dependent fashion. ScPdr3 requires the presence of a transcriptional Mediator subunit called Gal11 (Med15) to fully induce ScPDR5 transcription in response to ρ0 signaling. ScPdr1 does not respond to either ρ0 signals or ScPsd1 overproduction. In this study, we employed transcriptional fusions between CgPdr1 target promoters, like CgCDR1, to demonstrate that CgPdr1 stimulates gene expression via binding to elements called pleiotropic drug response elements (PDREs). Deletion mapping and electrophoretic mobility shift assays demonstrated that a single PDRE in the CgCDR1 promoter was capable of supporting ρ0-induced gene expression. Removal of one of the two ScGal11 homologues from C. glabrata caused a major defect in drug-induced expression of CgCDR1 but had a quantitatively minor effect on ρ0-stimulated transcription. These data demonstrate that CgPdr1 appears to combine features of ScPdr1 and ScPdr3 to produce a transcription factor with chimeric regulatory properties. PMID:21131438

Interactions between Candida albicans and Candida glabrata in biofilms: Influence of the strain type, culture medium and glucose supplementation.

PubMed

Hosida, Thayse Yumi; Cavazana, Thamires Priscila; Henriques, Mariana; Pessan, Juliano Pelim; Delbem, Alberto Carlos Botazzo; Monteiro, Douglas Roberto

2018-04-01

The relationship among Candida species may be influenced by several factors. Thus, this study evaluated the interactions between Candida albicans and Candida glabrata in biofilms, varying the strain type, culture medium and glucose supplementation. Biofilms were formed for 48 hours in Sabouraud dextrose broth (SDB) or RPMI 1640, supplemented with 0%, 1% or 5% glucose. Each strain of C. albicans was combined with two strains of C. glabrata, generating four biofilm associations, which were quantified by colony-forming units (CFUs), total biomass and metabolic activity. Data were analysed by ANOVA and Tukey's HSD test (α = 0.05). For CFUs, all associations were classified as indifferent for biofilms formed in RPMI 1640, while for SDB the interactions were antagonistic for C. albicans and indifferent for C. glabrata. The association of reference strains resulted in a dual-species biofilm with biomass significantly higher than that observed for each single biofilm developed in SDB. The metabolic activity of dual-species biofilms did not significantly differ from that found for single ones, except for co-culture of the reference strains. Glucose supplementation and culture media had a significant influence on all parameters. In conclusion, the strain type, culture medium and glucose supplementation influenced the interactions between C. albicans and C. glabrata. © 2017 Blackwell Verlag GmbH.

SNF3 as High Affinity Glucose Sensor and Its Function in Supporting the Viability of Candida glabrata under Glucose-Limited Environment.

PubMed

Ng, Tzu Shan; Chew, Shu Yih; Rangasamy, Premmala; Mohd Desa, Mohd N; Sandai, Doblin; Chong, Pei Pei; Than, Leslie Thian Lung

2015-01-01

Candida glabrata is an emerging human fungal pathogen that has efficacious nutrient sensing and responsiveness ability. It can be seen through its ability to thrive in diverse range of nutrient limited-human anatomical sites. Therefore, nutrient sensing particularly glucose sensing is thought to be crucial in contributing to the development and fitness of the pathogen. This study aimed to elucidate the role of SNF3 (Sucrose Non Fermenting 3) as a glucose sensor and its possible role in contributing to the fitness and survivability of C. glabrata in glucose-limited environment. The SNF3 knockout strain was constructed and subjected to different glucose concentrations to evaluate its growth, biofilm formation, amphotericin B susceptibility, ex vivo survivability and effects on the transcriptional profiling of the sugar receptor repressor (SRR) pathway-related genes. The CgSNF3Δ strain showed a retarded growth in low glucose environments (0.01 and 0.1%) in both fermentation and respiration-preferred conditions but grew well in high glucose concentration environments (1 and 2%). It was also found to be more susceptible to amphotericin B in low glucose environment (0.1%) and macrophage engulfment but showed no difference in the biofilm formation capability. The deletion of SNF3 also resulted in the down-regulation of about half of hexose transporters genes (four out of nine). Overall, the deletion of SNF3 causes significant reduction in the ability of C. glabrata to sense limited surrounding glucose and consequently disrupts its competency to transport and perform the uptake of this critical nutrient. This study highlighted the role of SNF3 as a high affinity glucose sensor and its role in aiding the survivability of C. glabrata particularly in glucose limited environment.

Developmental toxicity, acute toxicity and mutagenicity testing in freshwater snails Biomphalaria glabrata (Mollusca: Gastropoda) exposed to chromium and water samples.

PubMed

Tallarico, Lenita de Freitas; Borrely, Sueli Ivone; Hamada, Natália; Grazeffe, Vanessa Siqueira; Ohlweiler, Fernanda Pires; Okazaki, Kayo; Granatelli, Amanda Tosatte; Pereira, Ivana Wuo; Pereira, Carlos Alberto de Bragança; Nakano, Eliana

2014-12-01

A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies. Copyright © 2014 Elsevier Inc. All rights reserved.

Demographic responses to multi-generation cadmium exposure in two strains of the freshwater gastropod, Biomphalaria glabrata.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salice, Christopher J.; Miller, Thomas J.; Roesijadi, Guritno

2008-08-20

A life table response experiment (LTRE) was used to quantify the population-level effects of continuous, multi-generation cadmium exposure on two strains of the freshwater gastropod, Biomphalaria glabrata; the parasite resistant BS90 and parasite susceptible NMRI strains. Snails were exposed to waterborne cadmium for three consecutive generations. Survival, growth and reproduction were measured empirically and incorporated into a stage-based, deterministic population model. Cadmium significantly affected hatching success, time to maturity and juvenile and adult survival in both strains. There were significant effects of generation on fecundity, hatching success time to maturity and juvenile survival in NMRI and time to maturity andmore » adult survival in BS90. Cadmium significantly affected the population growth rate, lambda (λ), in BS90. Cadmium, generation and the cadmium x generation interaction had significant effects on λ in NMRI. At the high cadmium exposure, λ for NMRI showed a decrease from generation 1 to generation 2 followed by and increase from generation 2 to 3. Lambda in high cadmium BS90 steadily decreased over the three generations while NMRI at this same concentration was similar to the controls. The results indicated that strain-specific differences in response to multi-generation cadmium exposure are evident in B. glabrata. Moreover, effects seen in the first generation are not necessarily indicative of effects in subsequent generations. Changes in λ over the course of the three-generation exposure suggest that acclimation and/or adaptation to cadmium may have occurred, particularly in NMRI at the high cadmium exposure level.« less

Differential transcriptomic responses of Biomphalaria glabrata (Gastropoda, Mollusca) to bacteria and metazoan parasites, Schistosoma mansoni and Echinostoma paraensei (Digenea, Platyhelminthes)

PubMed Central

Adema, Coen M; Hanington, Patrick C.; Lun, Cheng-Man; Rosenberg, George H.; Aragon, Anthony D; Stout, Barbara A; Richard, Mara L. Lennard; Gross, Paul S.; Loker, Eric S

2009-01-01

A 70-mer oligonucleotide-based microarray (1152 features) that emphasizes stress and immune responses factors was constructed to study transcriptomic responses of the snail Biomphalaria glabrata to different immune challenges. In addition to sequences with relevant putative ID and Gene Ontology (GO) annotation, the array features non-immune factors and unknown B. glabrata ESTs for functional gene discovery. The transcription profiles of B. glabrata (3 biological replicates, each a pool of 5 snails) were recorded at 12 hours post wounding, exposure to Gram negative or Gram positive bacteria (Escherichia coli and Micrococcus luteus, respectively), or infection with compatible trematode parasites (S. mansoni or E. paraensei, 20 miracidia/snail), relative to controls, using universal reference RNA. The data were subjected to Significance Analysis for Microarrays (SAM), with a false positive rate (FPR) ≤10%. Wounding yielded a modest differential expression profile (27 up/21 down) with affected features mostly dissimilar from other treatments. Partially overlapping, yet distinct expression profiles were recorded from snails challenged with E. coli (83 up/20 down) or M. luteus (120 up/42 down), mostly showing up-regulation of defense and stress-related features. Significantly altered expression of selected immune features indicates that B. glabrata detects and responds differently to compatible trematodes. Echinostoma paraensei infection was associated mostly with down regulation of many (immune-) transcripts (42 up/68 down), whereas S. mansoni exposure yielded a preponderance of up-regulated features (140 up/23 down), with only few known immune genes affected. These observations may reflect the divergent strategies developed by trematodes during their evolution as specialized pathogens of snails to negate host defense responses. Clearly, the immune defenses of B. glabrata distinguish and respond differently to various immune challenges. PMID:19962194

Differentiation of Candida albicans, Candida glabrata, and Candida krusei by FT-IR and chemometrics by CHROMagar™ Candida.

PubMed

Wohlmeister, Denise; Vianna, Débora Renz Barreto; Helfer, Virginia Etges; Calil, Luciane Noal; Buffon, Andréia; Fuentefria, Alexandre Meneghello; Corbellini, Valeriano Antonio; Pilger, Diogo André

2017-10-01

Pathogenic Candida species are detected in clinical infections. CHROMagar™ is a phenotypical method used to identify Candida species, although it has limitations, which indicates the need for more sensitive and specific techniques. Infrared Spectroscopy (FT-IR) is an analytical vibrational technique used to identify patterns of metabolic fingerprint of biological matrixes, particularly whole microbial cell systems as Candida sp. in association of classificatory chemometrics algorithms. On the other hand, Soft Independent Modeling by Class Analogy (SIMCA) is one of the typical algorithms still little employed in microbiological classification. This study demonstrates the applicability of the FT-IR-technique by specular reflectance associated with SIMCA to discriminate Candida species isolated from vaginal discharges and grown on CHROMagar™. The differences in spectra of C. albicans, C. glabrata and C. krusei were suitable for use in the discrimination of these species, which was observed by PCA. Then, a SIMCA model was constructed with standard samples of three species and using the spectral region of 1792-1561cm -1 . All samples (n=48) were properly classified based on the chromogenic method using CHROMagar™ Candida. In total, 93.4% (n=45) of the samples were correctly and unambiguously classified (Class I). Two samples of C. albicans were classified correctly, though these could have been C. glabrata (Class II). Also, one C. glabrata sample could have been classified as C. krusei (Class II). Concerning these three samples, one triplicate of each was included in Class II and two in Class I. Therefore, FT-IR associated with SIMCA can be used to identify samples of C. albicans, C. glabrata, and C. krusei grown in CHROMagar™ Candida aiming to improve clinical applications of this technique. Copyright © 2017 Elsevier B.V. All rights reserved.

Molluscicidal and ovicidal activities of plant extracts of the Piperaceae on Biomphalaria glabrata (Say, 1818).

PubMed

Rapado, L N; Nakano, E; Ohlweiler, F P; Kato, M J; Yamaguchi, L F; Pereira, C A B; Kawano, T

2011-03-01

Schistosomiasis is a tropical disease caused by Schistosoma and occurs in 54 countries, mainly in South America, the Caribbean region, Africa and the eastern Mediterranean. Currently, 5 to 6 million Brazilian people are infected and 30,000 are under infection risk. Typical of poor regions, this disease is associated with the lack of basic sanitation and very frequently to the use of contaminated water in agriculture, housework and leisure. One of the most efficient methods of controlling the disease is application of molluscicides to eliminate or to reduce the population of the intermediate host snail Biomphalaria glabrata. Studies on molluscicidal activity of plant extracts have been stimulated by issues such as environmental preservation, high cost and recurrent resistance of snails to synthetic molluscicides. The aim of this study was to determine the molluscicide action of extracts from Piperaceae species on adult and embryonic stages of B. glabrata. Fifteen extracts from 13 Piperaceae species were obtained from stems, leaves and roots. Toxicity of extracts was evaluated against snails at two different concentrations (500 and 100 ppm) and those causing 100% mortality at 100 ppm concentration were selected to obtain the LC₉₀ (lethal concentration of 90% mortality). Piper aduncum, P. crassinervium, P. cuyabanum, P. diospyrifolium and P. hostmannianum gave 100% mortality of adult snails at concentrations ranging from 10 to 60 ppm. These extracts were also assayed on embryonic stages of B. glabrata and those from P. cuyabanum and P. hostmannianum showed 100% ovicidal action at 20 ppm.

Candida species isolated from different body sites and their antifungal susceptibility pattern: Cross-analysis of Candida albicans and Candida glabrata biofilms.

PubMed

Cataldi, Valentina; Di Campli, Emanuela; Fazii, Paolo; Traini, Tonino; Cellini, Luigina; Di Giulio, Mara

2017-08-01

Candida species are regular commensal in humans, but-especially in immunocompromised patients-they represent opportunistic pathogens giving rise to systemic infection. The aim of the present work was to isolate and characterize for their antifungal profile Candida species from different body sites and to analyze the biofilms produced by C. albicans and C. glabrata isolates. Eighty-one strains of Candida species from 77 patients were identified. Epidemiological study showed that the most isolated species were C. albicans (44), C. glabrata (13) and C. parapsilosis (13) mainly from Hematology, Infectious Diseases, Medicine, Neonatology and Oncology Divisions, the majority of the biological samples were swabs (44) and blood cultures (16). The analysis of the biofilm formation was performed at 24 and 48-hours comparing resistant and susceptible strains of C. albicans to resistant and susceptible strains of C. glabrata. Candida albicans has a greater ability to form biofilm compared to C. glabrata, both in the susceptible and resistant strains reaching maturity after 24 hours with a complex structure composed of blastospores, pseudohyphae, and hyphae embedded in a matrix. On the contrary, C. glabrata biofilm was composed exclusively of blastospores that in the resistant strain, after 24 hours, were organized in a compact multilayer different to the discontinuous structure observed in the susceptible analyzed strains. In conclusion, the increasing of the incidence of Candida species infection together with their emerging drug resistance also related to the biofilm forming capability underline the need to monitor their distribution and susceptibility patterns for improving the surveillance and for a correct management of the infection. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

ER stress response mechanisms in the pathogenic yeast Candida glabrata and their roles in virulence

PubMed Central

Miyazaki, Taiga; Kohno, Shigeru

2014-01-01

The maintenance of endoplasmic reticulum (ER) homeostasis is critical for numerous aspects of cell physiology. Eukaryotic cells respond to the accumulation of misfolded proteins in the ER (ER stress) by activating the unfolded protein response (UPR), an intracellular signaling pathway that adjusts the folding capacity of the ER. Recent studies of several pathogenic fungi have revealed that the UPR is important for antifungal resistance and virulence; therefore, the pathway has attracted much attention as a potential therapeutic target. While the UPR is highly conserved among eukaryotes, our group recently discovered that the pathogenic yeast Candida glabrata lacks the typical fungal UPR, but possesses alternative mechanisms to cope with ER stress. This review summarizes how C. glabrata responds to ER stress and discusses the impacts of ER quality control systems on antifungal resistance and virulence. PMID:24335436

Candida glabrata species complex prevalence and antifungal susceptibility testing in a culture collection: First description of Candida nivariensis in Argentina.

PubMed

Morales-López, Soraya Eugenia; Taverna, Constanza G; Bosco-Borgeat, María Eugenia; Maldonado, Ivana; Vivot, Walter; Szusz, Wanda; Garcia-Effron, Guillermo; Córdoba, Susana B

2016-12-01

The presence of the cryptic species belonging to the Candida glabrata complex has not been studied in Argentina. We analyzed a collection of 117 clinical isolates of C. glabrata complex belonging to a National Culture Collection of Instituto Nacional de Microbiología "Dr. Carlos G. Malbrán" from Argentina (40 isolates from blood samples, 18 from other normally sterile sites, 20 from vagina, 14 from urine, 7 from oral cavity, 3 from catheter, 1 from a stool sample and 14 isolates whose clinical origin was not recorded). The aims of this work were to determine the prevalence of the cryptic species Candida nivariensis and Candida bracarensis and to evaluate the susceptibility profile of isolates against nine antifungal drugs. Identification was carried out by using classical phenotypic tests, CHROMagar™ Candida, PCR and MALDI-TOF. The minimal inhibitory concentrations of amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, voriconazole, ketoconazole, posaconazole, caspofungin and anidulafungin were determined according to the EDef 7.3 (EUCAST) reference document. Of the 117 isolates, 114 were identified as C. glabrata and three as C. nivariensis by using PCR and MALDI-TOF. There were no major differences between C. nivariensis and C. glabrata susceptibility profiles. No resistant strains were found to echinocandins. We have found that the percentage of C. nivariensis in our culture collection was 2.56. This is the first description of C. nivariensis in Argentina, and data obtained could contribute to the knowledge of the epidemiology of this cryptic species.

The Compatibility Between Biomphalaria glabrata Snails and Schistosoma mansoni: An Increasingly Complex Puzzle.

PubMed

Mitta, G; Gourbal, B; Grunau, C; Knight, M; Bridger, J M; Théron, A

2017-01-01

This review reexamines the results obtained in recent decades regarding the compatibility polymorphism between the snail, Biomphalaria glabrata, and the pathogen, Schistosoma mansoni, which is one of the agents responsible for human schistosomiasis. Some results point to the snail's resistance as explaining the incompatibility, while others support a "matching hypothesis" between the snail's immune receptors and the schistosome's antigens. We propose here that the two hypotheses are not exclusive, and that the compatible/incompatible status of a particular host/parasite couple probably reflects the balance of multiple molecular determinants that support one hypothesis or the other. Because these genes are involved in a coevolutionary arms race, we also propose that the underlying mechanisms can vary. Finally, some recent results show that environmental factors could influence compatibility. Together, these results make the compatibility between B. glabrata and S. mansoni an increasingly complex puzzle. We need to develop more integrative approaches in order to find targets that could potentially be manipulated to control the transmission of schistosomiasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Opportunistic pathogen Candida glabrata and the mechanisms of its resistance to antifungal drugs].

PubMed

Berila, N; Subík, J

2010-04-01

Treatment of not only bacterial but also fungal infections is currently a growing concern. A major reason is the acquisition of multidrug resistance in both prokaryotic and human cells. The multidrug resistance phenotype is a cellular response to the presence of cytotoxic substances in the environment. The basic mechanism of multidrug resistance is overexpression of the membrane proteins involved in the extrusion of toxic substances outside the cell. The resistance mechanism based on the efflux of inhibitors as a result of the overproduction of transport proteins was also observed in some plant and animal pathogens and human tumour cells. The phenomenon of multidrug resistance associated with an excessive and long-term use of antifungals, in particular of azole derivatives, was also confirmed in the yeast Candida glabrata which is becoming a growing concern for health care professionals. Reduced susceptibility to azole derivatives in particular, a high potential for adapting to stressors, and multiple mechanisms of resistance to structurally and functionally unrelated antifungal drugs make the species C. glabrata a potential threat to hospital patients.

In Vitro Fungicidal Activities of Anidulafungin, Caspofungin, and Micafungin against Candida glabrata, Candida bracarensis, and Candida nivariensis Evaluated by Time-Kill Studies

PubMed Central

Gil-Alonso, Sandra; Jauregizar, Nerea; Cantón, Emilia; Eraso, Elena

2015-01-01

Anidulafungin, caspofungin, and micafungin killing activities against Candida glabrata, Candida bracarensis, and Candida nivariensis were evaluated by the time-kill methodology. The concentrations assayed were 0.06, 0.125, and 0.5 μg/ml, which are achieved in serum. Anidulafungin and micafungin required between 13 and 26 h to reach the fungicidal endpoint (99.9% killing) against C. glabrata and C. bracarensis. All echinocandins were less active against C. nivariensis. PMID:25801575

Identification of a polysaccharide produced by the pyruvate overproducer Candida glabrata CCTCC M202019.

PubMed

Luo, Zhengshan; Liu, Song; Du, Guocheng; Zhou, Jingwen; Chen, Jian

2017-06-01

Candida glabrata has great potential for the accumulation of pyruvate as a preferred strain in pyruvate production by fermentation. However, its substrate conversion rate is relatively low. In this study, a novel polysaccharide containing α-1,4-glucosidic bonds was observed accidentally in screening a high-titer pyruvate strain by atmospheric and room temperature plasma mutagenesis of C. glabrata. Chemical analysis of the partially purified polysaccharide S 4-C10 showed the main components were 1.2% (w/w) protein and 94.2% (w/w) total sugar. Fourier transform infrared and molecular mass distribution analysis indicated that the main component (PSG-2) of S 4-C10 was a small molecular homogeneous protein-bound polysaccharide. Monosaccharide analysis of PSG-2 showed it consisted of glucose, mannose, and fructose. By optimizing the vitamin mix content, 77.6 g L -1 S 4-C10 polysaccharide could be obtained after 72 h fermentation at 30 °C in 500-mL flasks. RT-qPCR analysis showed that transcriptional level of some key genes related to polysaccharide biosynthesis was upregulated compared to that of wild-type strain. By knocking out two most significantly upregulated genes, CAGL0H02695g and CAGL0K10626g, in the wild-type strain, the pyruvate consumption rate was significantly reduced in late pyruvate fermentation phase, while the titer of polysaccharides was reduced by 18.0%. Besides the potential applications of the novel identified polysaccharide, this study provided clues for increasing the conversion ratio of glucose to pyruvate in C. glabrata by further decreasing the accumulation of polysaccharides.

cDNA cloning, characterization and expression analysis of a novel antimicrobial peptide gene penaeidin-3 (Fi-Pen3) from the haemocytes of Indian white shrimp Fenneropenaeus indicus.

PubMed

Shanthi, S; Vaseeharan, B

2012-03-20

A new member of antimicrobial peptide genes of the penaeidin family, penaeidin 3, was cloned from the haemocytes of Indian white shrimp Fenneropeneaus indicus (F. indicus), by reverse transcription PCR (RT-PCR) and rapid amplification of cDNA end (RACE-PCR) methods. The complete nucleotide sequence of cDNA clone of Indian white shrimp F. indicus Penaeidin 3 (Fi-Pen3) was 243bp long and has an open reading frame which encodes 80 amino acid peptide. The homology analysis of Fi-Pen3 sequence with other Penaeidins 3 shows higher similarity with Penaeus monodon (92%). The theoretical 3D structure generated through ab initio modelling indicated the presence of two-disulphide bridges in the alpha-helix. The signal peptide sequence of Fi-Pen3 is almost entirely homologous to that of other Penaeidin 3 of crustaceans, while differing relatively in the N-terminal domain of the mature peptide. The mature peptide has a predicted molecular weight of 84.9kDa, and a theoretical pI of 9.38. Phylogenetic analysis of Fi-Pen3 shows high resemblance with other Pen-3 from P. monodon, Litopenaeus stylirostris, Litopenaeus vannamei and Litopenaeus setiferus. Fi-Pen3 found to be expressed in haemocytes, heart, hepatopancreas, muscles, gills, intestine, and eyestalk with higher expression in haemocytes. Microbial challenge resulted in mRNA up-regulation, up to 6h post injection of Vibrio parahemolyticus. The Fi-Pen3 mRNA expression of F. indicus in the premolt stage (D(01) and D(02)) was significantly up-regulated than the postmolt (A and B) and intermolt stages (C). The findings of the present paper underline the involvement of Fi-Pen3 in innate immune system of F. indicus. Copyright © 2011 Elsevier GmbH. All rights reserved.

Evaluation of the mitochondrial system in the gonad-digestive gland complex of Biomphalaria glabrata (Mollusca, Gastropoda) after infection by Echinostoma paraensei (Trematoda, Echinostomatidae).

PubMed

Tunholi, Victor Menezes; Tunholi-Alves, Vinícius Menezes; Santos, Anderson Teixeira; Garcia, Juberlan da Silva; Maldonado, Arnaldo; da-Silva, Wagner Seixas; Rodrigues, Maria de Lurdes de Azevedo; Pinheiro, Jairo

2016-05-01

The effect of infection by Echinostoma paraensei on the mitochondrial physiology of Biomphalaria glabrata was investigated after exposure to 50 miracidia. The snails were dissected one, two, three and four weeks after infection for collection and mechanical permeabilization of the gonad-digestive gland (DGG) complex. The results obtained indicate that prepatent infection by this echinostomatid fluke significantly suppresses the phosphorylation state (respiratory state 3) and basal oxygen consumption of B. glabrata, demonstrating that the infection reduces the ability of the intermediate host to carry out aerobic oxidative reactions. Additionally, relevant variations related to the uncoupled mitochondrial (state 3u) of B. glabrata infected by E. paraensei were observed. Four weeks after exposure, a significant reduction in mitochondrial oxygen consumption after addition of ADP (3.68±0.26pmol O2/mg proteins) was observed in the infected snails in comparison with the respective control group (5.14±0.25). In the uncoupled state, the infected snails consumed about 62% less oxygen than the infected snails (7.87±0.84pmol O2/mg proteins) in the same period. These results demonstrate a reduction in oxidative decarboxylation rate of the tricarboxylic acid cycle and faster anaerobic degradation of carbohydrates in the infected snails. The possible mechanisms that explain this new metabolic condition in the infected organisms are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Drug susceptibility profile of Candida glabrata clinical isolates from Iran and genetic resistant mechanisms to caspofungin.

PubMed

Amanloo, Saeid; Shams-Ghahfarokhi, Masoomeh; Ghahri, Mohammad; Razzaghi-Abyaneh, Mehdi

2018-04-20

Candida glabrata is a yeast that can cause hazardous fungal infections with high mortality and drug resistance. The aim of this study was to determine the profile of drug susceptibility in clinical isolates of C. glabrata and review the resistance mechanisms to caspofungin. A total of 50 C. glabrata clinical isolates from Iran were tested for in vitro susceptibilities to amphotericin B, caspofungin, fluconazole and voriconazole. To investigate the mechanism of resistance to caspofungin, hotspot areas of FKS1 and FKS2 genes were sequenced and gene expression profile was evaluated. All the isolates were susceptible to amphotericin B and caspofungin. Fluconazole resistance was exhibited in four isolates. In addition, only one isolate was resistant to voriconazole. FKS2 with 12 point mutations showed more mutations compared to FKS1 that had only two mutations. All substitutions were synonymous. FKS genes were expressed at comparable levels (no statistical significance) in caspofungin-treated and non-treated cultures. The silent mutations in the hotspot areas of FKS genes and inconsiderable changes in gene expression were not associated with increased MIC (0.25μg/ml). Other mechanisms of resistance which include mutations outside the hotspot area of FKS genes could be involved in a slight increase of MIC, and they should be identified through complete FKS gene sequencing. Copyright © 2018 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Time to Positivity and Detection of Growth in Anaerobic Blood Culture Vials Predict the Presence of Candida glabrata in Candidemia: a Two-Center European Cohort Study

PubMed Central

Kaasch, Achim J.; Soriano, Alex; Torres, Jorge-Luis; Vergara, Andrea; Morata, Laura; Zboromyrska, Yuliya; De La Calle, Cristina; Alejo, Izaskun; Hernández, Cristina; Cardozo, Celia; Marco, Franscesc; Del Río, Ana; Almela, Manel; Mensa, Josep; Martínez, José Antonio

2014-01-01

This study shows the accuracy of exclusive or earlier growth in anaerobic vials to predict Candida glabrata in a large series of candidemic patients from two European hospitals using the Bactec 9240 system. Alternatively, C. glabrata can be predicted by a time to positivity cutoff value, which should be determined for each setting. PMID:24899027

Effects of antifungal agents alone and in combination against Candida glabrata strains susceptible or resistant to fluconazole.

PubMed

Alves, Izabel Almeida; Bandeira, Laíssa Arévalo; Mario, Débora Alves Nunes; Denardi, Laura Bedin; Neves, Louise Vignoles; Santurio, Janio Morais; Alves, Sydney Hartz

2012-09-01

The rise of Candida spp. resistant to classic triazole antifungal agents has led to a search for new therapeutic options. Here, we evaluated combinations of antifungals in a checkerboard assay against two groups of Candida glabrata strains: one containing fluconazole-susceptible clinical isolates (FS) and another containing fluconazole-resistant laboratory derivative (FR). The most synergistic combination observed was amphotericin B + flucytosine (synergistic for 61.77 % of FS strains and 76.47 % of FR strains). The most antagonistic combination observed was ketoconazole + flucytosine (FS 61.77 % and FR 55.88 %). Surprisingly, most combinations evidenced indifferent interactions, and the best synergism appeared when amphotericin B and flucytosine were combined against both groups of isolates.

Comparative Study of the Effects of Fluconazole and Voriconazole on Candida glabrata, Candida parapsilosis and Candida rugosa Biofilms.

PubMed

Madhavan, Priya; Jamal, Farida; Pei, Chong Pei; Othman, Fauziah; Karunanidhi, Arunkumar; Ng, Kee Peng

2018-06-01

Infections by non-albicans Candida species are a life-threatening condition, and formation of biofilms can lead to treatment failure in a clinical setting. This study was aimed to demonstrate the in vitro antibiofilm activity of fluconazole (FLU) and voriconazole (VOR) against C. glabrata, C. parapsilosis and C. rugosa with diverse antifungal susceptibilities to FLU and VOR. The antibiofilm activities of FLU and VOR in the form of suspension as well as pre-coatings were assessed by XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay. Morphological and intracellular changes exerted by the antifungal drugs on Candida cells were examined by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of the antibiofilm activities showed that FLU drug suspension was capable of killing C. parapsilosis and C. rugosa at minimum inhibitory concentrations (MICs) of 4× MIC FLU and 256× MIC FLU, respectively. While VOR MICs ranging from 2× to 32× were capable of killing the biofilms of all Candida spp tested. The antibiofilm activities of pre-coated FLU were able to kill the biofilms at ¼× MIC FLU and ½× MIC FLU for C. parapsilosis and C. rugosa strains, respectively. While pre-coated VOR was able to kill the biofilms, all three Candida sp at ½× MIC VOR. SEM and TEM examinations showed that FLU and VOR treatments exerted significant impact on Candida cell with various degrees of morphological changes. In conclusion, a fourfold reduction in MIC 50 of FLU and VOR towards ATCC strains of C. glabrata, C. rugosa and C. rugosa clinical strain was observed in this study.

Fungal CYP51 Inhibitors VT-1161 and VT-1129 Exhibit Strong In Vitro Activity against Candida glabrata and C. krusei Isolates Clinically Resistant to Azole and Echinocandin Antifungal Compounds.

PubMed

Schell, W A; Jones, A M; Garvey, E P; Hoekstra, W J; Schotzinger, R J; Alexander, B D

2017-03-01

The in vitro activities of fungal CYP51 inhibitors VT-1161 and VT-1129 were determined for Candida glabrata ( n = 34) and C. krusei ( n = 50). C. glabrata isolates were screened for FKS gene mutations. All isolates were resistant clinically and/or in vitro to at least one standard antifungal compound. VT-1161 and VT-1129 MICs for all isolates were at least 5-fold below achievable human plasma levels for VT-1161. VT-1161 and VT-1129 are promising for the treatment of resistant C. glabrata and C. krusei infections. Copyright © 2017 American Society for Microbiology.

Time to positivity and detection of growth in anaerobic blood culture vials predict the presence of Candida glabrata in candidemia: a two-center European cohort study.

PubMed

Cobos-Trigueros, Nazaret; Kaasch, Achim J; Soriano, Alex; Torres, Jorge-Luis; Vergara, Andrea; Morata, Laura; Zboromyrska, Yuliya; De La Calle, Cristina; Alejo, Izaskun; Hernández, Cristina; Cardozo, Celia; Marco, Franscesc; Del Río, Ana; Almela, Manel; Mensa, Josep; Martínez, José Antonio

2014-08-01

This study shows the accuracy of exclusive or earlier growth in anaerobic vials to predict Candida glabrata in a large series of candidemic patients from two European hospitals using the Bactec 9240 system. Alternatively, C. glabrata can be predicted by a time to positivity cutoff value, which should be determined for each setting. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Probing the Active Site of Candida Glabrata Dihydrofolate Reductase with High Resolution Crystal Structures and the Synthesis of New Inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J.; Bolstad, D; Smith, A

2009-01-01

Candida glabrata, a fungal strain resistant to many commonly administered antifungal agents, has become an emerging threat to human health. In previous work, we validated that the essential enzyme, dihydrofolate reductase, is a drug target in C. glabrata. Using a crystal structure of dihydrofolate reductase from C. glabrata bound to an initial lead compound, we designed a class of biphenyl antifolates that potently and selectively inhibit both the enzyme and the growth of the fungal culture. In this work, we explore the structure-activity relationships of this class of antifolates with four new high resolution crystal structures of enzyme:inhibitor complexes andmore » the synthesis of four new inhibitors. The designed inhibitors are intended to probe key hydrophobic pockets visible in the crystal structure. The crystal structures and an evaluation of the new compounds reveal that methyl groups at the meta and para positions of the distal phenyl ring achieve the greatest number of interactions with the pathogenic enzyme and the greatest degree of selectivity over the human enzyme. Additionally, antifungal activity can be tuned with substitution patterns at the propargyl and para-phenyl positions.« less

Effects of hypoxia on dopamine concentration and the immune response of White Shrimp ( Litopenaeus vannamei)

NASA Astrophysics Data System (ADS)

Hu, Fawen; Pan, Luqing; Jing, Futao

2009-03-01

Effects of hypoxia on the dopamine concentration and the immune response of White Shrimp Litopenaeus vannamei were studied. The results showed that hypoxia had significant effects on the concentration of dopamine (DA) in the haemolymph, haemocyte count, phenoloxidase activity, phagocytic activity of haemocytes and bacteriolytic and antibacterial activity in the haemolymph ( P<0.05). The concentration of the dopamine in haemolymph reached its maximum in the 3.0 and 1.5 mg L-1 DO groups at 12 h and 6 h, and then returned to normal after 24 h and 12 h, respectively. All immune parameters decreased with the reduction of dissolved oxygen. Total haemocyte count (THC), the hyaline cells and semi-granular cells in the 3.0 mg L-1 DO group became stable after 12 h, while granular cells did so after 24 h. The THC and different haemocyte count (DHC) in the 1.5 mg L-1 DO group became stable after 24 h. Phenoloxidase activity and bacteriolytic activity in the 3.0 and 1.5 mg L-1 DO groups reached their stable levels after 24 h and 12 h respectively, while phagocytic activity and antibacterial activity became stable after 24 and 12, and 36 and 24 h, respectively. It was also indicated that the changes of dopamine concentrations in haemolymph, haemocyte count and phenoloxidase activity were obviously related to the exposure time under hypoxic conditions.

Female biased sex-ratio in Schistosoma mansoni after exposure to an allopatric intermediate host strain of Biomphalaria glabrata.

PubMed

Lepesant, Julie M J; Boissier, Jérôme; Climent, Déborah; Cosseau, Céline; Grunau, Christoph

2013-10-01

For parasites that require multiple hosts to complete their development, the interaction with the intermediate host may have an impact on parasite transmission and development in the definitive host. The human parasite Schistosoma mansoni needs two different hosts to complete its life cycle: the freshwater snail Biomphalaria glabrata (in South America) as intermediate host and a human or rodents as final host. To investigate the influence of the host environment on life history traits in the absence of selection, we performed experimental infections of two B. glabrata strains of different geographic origin with the same clonal population of S. mansoni. One B. glabrata strain is the sympatric host and the other one the allopatric host. We measured prevalence in the snail, the cercarial infectivity, sex-ratio, immunopathology in the final host and microsatellite frequencies of individual larvae in three successive generations. We show that, even if the parasite population is clonal based on neutral markers, S. mansoni keeps the capacity of generating phenotypic plasticity and/or variability for different life history traits when confront to an unusual environment, in this study the intermediate host. The most dramatic change was observed in sex-ratio: in average 1.7 times more female cercariae were produced when the parasite developed in an allopatric intermediate host. Copyright © 2013 Elsevier Inc. All rights reserved.

[Evaluation of a trial to control Biomphalaria glabrata in Guadeloupe by using a sterilizing trematode (author's transl)].

PubMed

Nassi, H; Pointier, J P; Golvan, Y J

1979-01-01

A trial of biological control of Biomphalaria glabrata was carried out in Guadeloupe by using Ribeiroia marini guadeloupensis Nassi, 1978, an autochtonal Trematode which sterilizes the snail vector of Schistosoma mansoni. The trial took place in a pond in which the population of B. glabrata presents an annual demographic cycle related to the alternation of dry and rainy seasons. About 8 millions eggs of R. marini were introduced in 15 months into the biotope. Despite the low yield of these introductions, due particularly to the high turbidity of the water, this trial gave positive results in the disappearance of almost all the snails. The analysis of the results concerning the evolution of the levels of the snails and of the prevalence shows that a comparable efficiency could be obtained by massive introductions of eggs during short periods.

Candida glabrata prosthetic joint infection, successfully treated with anidulafungin: A case report and review of the literature.

PubMed

Koutserimpas, Christos; Samonis, George; Velivassakis, Emmanouil; Iliopoulou-Kosmadaki, Stylliani; Kontakis, Georgios; Kofteridis, Diamantis P

2018-04-01

Non-albicans Candida prosthetic joint infection (PJI) is extremely rare. A case of a Candida glabrata knee PJI is a 68-year-old splenectomised female smoker, suffering from chronic obstructive pulmonary disease (COPD) and alcoholism is reported. The patient presented with a peri-prosthetic fracture, 15 years after total knee replacement surgery. Cultures of the intraoperative peri-prosthetic tissue and materials yielded C. glabrata, as well as a methicillin-resistant S. epidermitis. The patient was treated with anidulafungin and vancomycin. The knee prosthetic joint was removed and cement-spacer with vancomycin and gentamycin was placed. Additionally, an external fixation was performed. A second stage revision surgery was planned, after completion of the antimicrobial and antifungal treatment. The patient is followed up for 4 months without signs, symptoms or findings of infection. PJI Candida infections require a high clinical suspicion index. It is of utmost importance to report these cases, since there is no consensus yet of the proper antifungal treatment. Furthermore, a literature review regarding treatment of those cases is provided. First-line treatment with an echinocandin seems most proper, due to their fungicidal properties, their effectiveness against biofilm, as well as their minimal toxicity, making them ideal for long-term use. Further experience is needed, for better understanding the disease's pathogenesis and optimal treatment. © 2017 Blackwell Verlag GmbH.

Enhanced oxidative killing of azole-resistant Candida glabrata strains with ERG11 deletion.

PubMed Central

Kan, V L; Geber, A; Bennett, J E

1996-01-01

The susceptibility of genetically defined Candida glabrata strains to killing by H2O2 and neutrophils was assessed. Fluconazole-susceptible L5L and L5D strains demonstrated survival rates higher than those of two fluconazole-resistant strains lacking the ERG11 gene coding for 14 alpha-demethylase. Fluconazole resistance can occur by mechanisms which increase fungal susceptibility to oxidative killing by H2O2 and neutrophils. PMID:8807069

An oyster species-specific miRNA scaffold42648_5080 modulates haemocyte migration by targeting integrin pathway.

PubMed

Chen, Hao; Wang, Hao; Jiang, Shuai; Xu, Jiachao; Wang, Lingling; Qiu, Limei; Song, Linsheng

2016-10-01

miRNAs are important gene regulators at post-transcriptional level and can modulate diverse biological processes, including immune response. Dozens of species-specific miRNAs have been identified in oyster Crassostrea gigas while their functions remain largely unknown. In the present study, an oyster species-specific miRNA scaffold42648_5080 was found responsive to LPS stimulation and might target a total of 31 oyster genes possibly involved in cell communication, cellular localization and cellular response to stimulus. Besides, in gain-of-function assay of scaffold42648_5080 in vivo, the phagocytosis (30.90% in miRNA group verse 23.20% in miRNA control group), apoptosis (3.10% in miRNA group verse 5.30% in miRNA control group) and migration rate (13.88% in miRNA group verse 21.03% in miRNA control group) of oyster haemocytes were found significantly altered after the injection of scaffold42648_5080 mimics. Among the target genes, integrin-linked kinase (CgILK) was considered crucial in cell migration and its interaction with scaffold42648_5080 was then verified both in vitro and in vivo. Consequently, a significant decrease of relative luciferase ratio was observed in CgILK 3'-UTR luciferase reporter assay after transfection of scaffold42648_5080 mimics (0.70-fold of that in blank group, p < 0.01). Meanwhile, when scaffold42648_5080 was overexpressed in vivo (5.41-fold of miRNA control group, p < 0.01), the expression of CgILK declined significantly to 0.25-fold of miRNA control group (p < 0.01). Comparatively, a significant decrease of the haemocyte migration rate (19.76% verse 34.82% in siEGFP control group, p < 0.01) was observed after knock-down of CgILK in vivo. The present study, as far as we know, for the first time revealed the immunomodulation role of an oyster species-specific miRNA, which might provide new insights into miRNA-mediated adaptation mechanism of oysters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced pyruvate production in Candida glabrata by carrier engineering.

PubMed

Luo, Zhengshan; Liu, Song; Du, Guocheng; Xu, Sha; Zhou, Jingwen; Chen, Jian

2018-02-01

Pyruvate is an important organic acid that plays a key role in the central metabolic pathway. Manipulating transporters is an efficient strategy to enhance production of target organic acids and a means to understand the effects of altered intracellular pyruvate content on global metabolic networks. Efforts have been made to manipulate mitochondrial pyruvate carrier (MPC) to transport pyruvate into different subcellular compartments in Candida glabrata to demonstrate the effects of the subcellular distribution of pyruvate on central carbon metabolism. By increasing the mitochondrial pyruvate content through enhancing the rate of pyruvate transport into mitochondria, a high central carbon metabolism rate, specific growth rate and specific pyruvate production rate were obtained. Comparing the intracellular pyruvate content of engineered and control strains showed that higher intracellular pyruvate levels were not conducive to improving pyruvate productivity or central carbon metabolism. Plasma membrane expression of MPCs significantly increased the expression levels of key rate-limiting glycolytic enzymes. Moreover, pyruvate production of CGΔura3-Sp-MPC1, CGΔura3-Sp-MPC2, and CGΔura3-Sp-MPC1-Sp-MPC2 increased 134.4%, 120.3%, and 30.0%, respectively. In conclusion, lower intracellular pyruvate content enhanced central carbon metabolism and provided useful clues for improving the production of other organic acids in microorganisms. © 2017 Wiley Periodicals, Inc.

Silver colloidal nanoparticles: effect on matrix composition and structure of Candida albicans and Candida glabrata biofilms.

PubMed

Monteiro, D R; Silva, S; Negri, M; Gorup, L F; de Camargo, E R; Oliveira, R; Barbosa, D B; Henriques, M

2013-04-01

The aim of this study was to assess the effect of different silver nanoparticles (SN) concentrations on the matrix composition and structure of Candida albicans and Candida glabrata biofilms. Candida biofilms were developed in 6-well microtiter plates during 48 h. After, these biofilms were exposed to 13.5 or 54 μg SN ml(-1) for 24 h. Then, extracellular matrices were extracted from biofilms and analysed chemically in terms of proteins, carbohydrates and DNA. To investigate the biofilm structure, scanning electron microscopy (SEM) and epifluorescence microscopy were used. SN interfered with the matrix composition of Candida biofilms tested in terms of protein, carbohydrate and DNA, except for the protein content of C. albicans biofilm. By SEM, Candida biofilms treated with SN revealed structural differences, when compared with the control groups. Further, SN showed a trend of agglomeration within the biofilms. Epifluorescence microscopy images suggest that SN induced damage on cell walls of the Candida isolates tested. In general, irrespective of concentration, SN affected the matrix composition and structure of Candida biofilms and these findings may be related to the mechanisms of biocide action of SN. This study reveals new insights about the behaviour of SN when in contact with Candida biofilms. SN may contribute to the development of therapies to prevent or control Candida infections. © 2012 The Society for Applied Microbiology.

Fluconazole Resistance Associated with Drug Efflux and Increased Transcription of a Drug Transporter Gene, PDH1, in Candida glabrata

PubMed Central

Miyazaki, Haruko; Miyazaki, Yoshitsugu; Geber, Antonia; Parkinson, Tanya; Hitchcock, Christopher; Falconer, Derek J.; Ward, Douglas J.; Marsden, Katherine; Bennett, John E.

1998-01-01

Sequential Candida glabrata isolates were obtained from the mouth of a patient infected with human immunodeficiency virus type 1 who was receiving high doses of fluconazole for oropharyngeal thrush. Fluconazole-susceptible colonies were replaced by resistant colonies that exhibited both increased fluconazole efflux and increased transcripts of a gene which codes for a protein with 72.5% identity to Pdr5p, an ABC multidrug transporter in Saccharomyces cerevisiae. The deduced protein had a molecular mass of 175 kDa and was composed of two homologous halves, each with six putative transmembrane domains and highly conserved sequences of ATP-binding domains. When the earliest and most azole-susceptible isolate of C. glabrata from this patient was exposed to fluconazole, increased transcripts of the PDR5 homolog appeared, linking azole exposure to regulation of this gene. PMID:9661006

[Comparison of microdilution and disk diffusion methods for the detection of fluconazole and voriconazole susceptibility against clinical Candida glabrata isolates and determination of changing susceptibility with new CLSI breakpoints].

PubMed

Hazırolan, Gülşen; Sarıbaş, Zeynep; Arıkan Akdağlı, Sevtap

2016-07-01

Candida albicans is the most frequently isolated species as the causative agent of Candida infections. However, in recent years, the isolation rate of non-albicans Candida species have increased. In many centers, Candida glabrata is one of the commonly isolated non-albicans species of C.glabrata infections which are difficult-to-treat due to decreased susceptibility to fluconazole and cross-resistance to other azoles. The aims of this study were to determine the in vitro susceptibility profiles of clinical C.glabrata isolates against fluconazole and voriconazole by microdilution and disk diffusion methods and to evaluate the results with both the previous (CLSI) and current species-specific CLSI (Clinical and Laboratory Standards Institute) clinical breakpoints. A total of 70 C.glabrata strains isolated from clinical samples were included in the study. The identification of the isolates was performed by morphologic examination on cornmeal Tween 80 agar and assimilation profiles obtained by using ID32C (BioMérieux, France). Broth microdilution and disk diffusion methods were performed according to CLSI M27-A3 and CLSI M44-A2 documents, respectively. The results were evaluated according to CLSI M27-A3 and M44-A2 documents and new vs. species-specific CLSI breakpoints. By using both previous and new CLSI breakpoints, broth microdilution test results showed that voriconazole has greater in vitro activity than fluconazole against C.glabrata isolates. For the two drugs tested, very major error was not observed with disk diffusion method when microdilution method was considered as the reference method. Since "susceptible" category no more exists for fluconazole vs. C.glabrata, the isolates that were interpreted as susceptible by previous breakpoints were evaluated as susceptible-dose dependent by current CLSI breakpoints. Since species-specific breakpoints remain yet undetermined for voriconazole, comparative analysis was not possible for this agent. The results obtained

Antifungal susceptibilities of Candida glabrata species complex, Candida krusei, Candida parapsilosis species complex and Candida tropicalis causing invasive candidiasis in China: 3 year national surveillance.

PubMed

Xiao, Meng; Fan, Xin; Chen, Sharon C-A; Wang, He; Sun, Zi-Yong; Liao, Kang; Chen, Shu-Lan; Yan, Yan; Kang, Mei; Hu, Zhi-Dong; Chu, Yun-Zhuo; Hu, Tie-Shi; Ni, Yu-Xing; Zou, Gui-Ling; Kong, Fanrong; Xu, Ying-Chun

2015-03-01

To define the antifungal susceptibility patterns of the most common non-albicans Candida spp. in China. We evaluated the susceptibilities to nine antifungal drugs of Candida parapsilosis species complex, Candida tropicalis, Candida glabrata species complex and Candida krusei isolates from patients with invasive candidiasis at 11 hospitals over 3 years. Isolates were identified by MALDI-TOF MS supplemented by DNA sequencing. MICs were determined by Sensititre YeastOne(TM) using current clinical breakpoints/epidemiological cut-off values to assign susceptibility (or WT), and by CLSI M44-A2 disc diffusion for fluconazole and voriconazole. Of 1072 isolates, 392 (36.6%) were C. parapsilosis species complex. C. tropicalis, C. glabrata species complex and C. krusei comprised 35.4%, 24.3% and 3.7% of the isolates, respectively. Over 99.3% of the isolates were of WT phenotype to amphotericin B and 5-flucytosine. Susceptibility/WT rates to azoles among C. parapsilosis species complex were ≥97.5%. However, 11.6% and 9.5% of C. tropicalis isolates were non-susceptible to fluconazole and voriconazole, respectively (7.1% were resistant to both). Approximately 14.3% of C. glabrata sensu stricto isolates (n = 258) were fluconazole resistant, and 11.6% of C. glabrata sensu stricto isolates were cross-resistant to fluconazole and voriconazole. All C. krusei isolates were susceptible/WT to voriconazole, posaconazole and itraconazole. Overall, 97.7%-100% of isolates were susceptible to caspofungin, micafungin and anidulafungin, but 2.3% of C. glabrata were non-susceptible to anidulafungin. There was no azole/echinocandin co-resistance. Disc diffusion and Sensititre YeastOne(TM) methods showed >95% categorical agreement for fluconazole and voriconazole. In summary, reduced azole susceptibility was seen among C. tropicalis. Resistance to echinocandins was uncommon. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial

New insights into the amphibious life of Biomphalaria glabrata and susceptibility of its egg masses to fungal infection

USDA-ARS?s Scientific Manuscript database

Egg masses of an aquatic snail, Biomphalaria glabrata, matured, and juveniles subsequently eclosed and were mobile in a stable water film of transitory habitats simulated by two different simple test devices described here. The viability of eggs maintained in an unstable film due to low ambient mois...

Accuracy of Sensititre YeastOne Echinocandins Epidemiological Cut-off Values for Identification of FKS mutant Candida albicans and Candida glabrata: A Ten Year National Survey of the Fungal Infection Network of Switzerland (FUNGINOS).

PubMed

Kritikos, A; Neofytos, D; Khanna, N; Schreiber, P W; Boggian, K; Bille, J; Schrenzel, J; Mühlethaler, K; Zbinden, R; Bruderer, T; Goldenberger, D; Pfyffer, G; Conen, A; Van Delden, C; Zimmerli, S; Sanglard, D; Bachmann, D; Marchetti, O; Lamoth, F

2018-06-14

Echinocandins represent the first-line treatment of candidemia. Acquired echinocandin resistance is mainly observed among Candida albicans and glabrata and is associated with FKS hotspot mutations. The commercial Sensititre YeastOne TM (SYO) kit is widely used for antifungal susceptibility testing, but interpretive clinical breakpoints are not well defined. We determined echinocandins epidemiological cut-off values (ECV) for C. albicans/glabrata tested by SYO and assessed their ability to identify FKS mutants in a national survey of candidemia. Bloodstream isolates of C. albicans and C. glabrata were collected in 25 Swiss hospitals from 2004 to 2013 and tested by SYO. FKS hotspot sequencing was performed for isolates with a minimal inhibitory concentration (MIC) ≥ECV for any echinocandin. 1277 C. albicans and 347 C. glabrata were included. ECV 97.5% [μg/ml] of caspofungin, anidulafungin and micafungin were 0.12, 0.06, 0.03 for C. albicans, and 0.25, 0.12, 0.03 for C. glabrata. FKS hotspot sequencing was performed for 70 isolates. No mutation was found in the 52 "limit wild-type" isolates (MIC=ECV for ≥1 echinocandin). Among the 18 "non wild-type" isolates (MIC>ECV for ≥1 echinocandin), FKS mutations were recovered in the only two isolates with MIC>ECV for all 3 echinocandins, but not in those exhibiting a "non wild-type" phenotype for only one or two echinocandins. This 10-year nationwide survey showed that the rate of echinocandin resistance among C. albicans and C. glabrata remains low in Switzerland despite increased echinocandin use. SYO-ECV could discriminate FKS mutants from wild-type isolates tested by SYO in this population. Copyright © 2018. Published by Elsevier Ltd.

Inactivation of Candida glabrata by a humid DC argon discharge afterglow: dominant contributions of short-lived aqueous active species

NASA Astrophysics Data System (ADS)

Xiong, Qing; Liu, Hongbin; Lu, Weiping; Chen, Qiang; Xu, Le; Wang, Xia; Zhu, Qunlin; Zeng, Xue; Yi, Ping

2017-05-01

Plasma medicine applications are currently attracting significant interest all over the world. Bactericidal treatments of Candida glabrata cultured in saline suspension are performed in this study by a room-temperature reactive afterglow of a DC-driven argon discharge. Water vapor was added to the discharge to study the inactivation contributions of reactive hydrolytic species including OH and H2O2 transporting along the gas flow to the treated solutions. The inactivation results indicate that the dominant roles in the bactericidal treatments are played by the short-lived aqueous active species, but not the stable species like H2O2aq (aq indicates an aqueous species). Further analysis shows that the ·OHaq radicals play an important role in the inactivation process. The ·OHaq radicals in the suspension are mostly produced from the direct dissolution of the OH species in the reactive afterglow. With the increase of added water vapor content, the ·OHaq production increases and enhances the inactivation efficiency of C. glabrata. Furthermore, it is found that the ambient air diffusion shows essential effects on the bactericidal activity of the remote humid argon discharge. Higher bactericidal effects can be obtained in open-space treatments compared to in a controlled Ar + H2O gas atmosphere. Key active air-byproduct species are believed to be generated in the suspension during the treatments and contributing to the inactivation process. Based on chemical analysis, the peroxynitrous acid ONOOHaq is considered as the key antimicrobial air-byproduct species. These results indicate the important dependence of plasma biomedical effects on the processing environment, which finally relates to the critical contributions of the key reactive species formed therein.

The Phosphoinositide 3-Kinase Regulates Retrograde Trafficking of the Iron Permease CgFtr1 and Iron Homeostasis in Candida glabrata*

PubMed Central

Sharma, Vandana; Purushotham, Rajaram; Kaur, Rupinder

2016-01-01

The phosphoinositide 3-kinase (PI3K), which phosphorylates phosphatidylinositol and produces PI3P, has been implicated in protein trafficking, intracellular survival, and virulence in the pathogenic yeast Candida glabrata. Here, we demonstrate PI3-kinase (CgVps34) to be essential for maintenance of cellular iron homeostasis. We examine how CgVps34 regulates the fundamental process of iron acquisition, and underscore its function in vesicular trafficking as a central determinant. RNA sequencing analysis revealed iron homeostasis genes to be differentially expressed upon CgVps34 disruption. Consistently, the Cgvps34Δ mutant displayed growth attenuation in low- and high-iron media, increased intracellular iron content, elevated mitochondrial aconitase activity, impaired biofilm formation, and extenuated mouse organ colonization potential. Furthermore, we demonstrate for the first time that C. glabrata cells respond to iron limitation by expressing the iron permease CgFtr1 primarily on the cell membrane, and to iron excess via internalization of the plasma membrane-localized CgFtr1 to the vacuole. Our data show that CgVps34 is essential for the latter process. We also report that macrophage-internalized C. glabrata cells express CgFtr1 on the cell membrane indicative of an iron-restricted macrophage internal milieu, and Cgvps34Δ cells display better survival in iron-enriched medium-cultured macrophages. Overall, our data reveal the centrality of PI3K signaling in iron metabolism and host colonization. PMID:27729452

The role of light and gravity in the experimental transmission of Echinostoma caproni (Digenea: Echinostomatidae) cercariae to the second intermediate host, Biomphalaria glabrata (Gastropoda: Pulmonata).

PubMed

Platt, Thomas R; Burnside, Lindsay; Bush, Elizabeth

2009-06-01

Trematode cercariae inhabit predictable environments and respond to trigger cues with genetically fixed releaser responses when foraging for the upstream host. The effect of light and gravity on the transmission of Echinostoma caproni cercariae to Biomphalaria glabrata was investigated experimentally. Transmission chambers were constructed of clear polyvinyl chloride pipe. Snails were constrained within the chamber to prevent movement, while permitting the cercariae to swim freely. A trial consisted of 2 infected B. glabrata shedding E. caproni cercariae placed at the center of the chamber, with 5 uninfected B. glabrata placed 10 cm on either side (or above and below) of the shedding snails as sentinels. There was no significant difference in the prevalence of infection sentinel snails in either experiment (light vs. dark or top vs. bottom); however, mean intensity was significantly higher in sentinel snails in the dark portion of the chamber (42.5 vs. 10.4; P = 0.001) and the top of the transmission chamber (66.1 vs. 38.0; P = 0.0003). There was a high correlation between the number of metacercariae collected from sentinel snails and the total number of infective units (metacercariae + unsuccessful cercariae): r = 0.992 (light vs. dark) and r = 0.957 (top vs. bottom), respectively, at cercariae densities estimated from 22 to 3,304/L. The results suggest that cercariae of E. caproni exhibit negative photo- and geotaxis in searching for a second intermediate host. Stereotypical releaser responses to environmental trigger cues (light and gravity) allow E. caproni cercariae to exploit flexible strategies for completing the life cycle consistent with the broad range second intermediate and definitive hosts used by E. caproni cercariae and adults, respectively.

Evaluation of a linear spectral mixture model and vegetation indices (NDVI and EVI) in a study of schistosomiasis mansoni and Biomphalaria glabrata distribution in the state of Minas Gerais, Brazil.

PubMed

Guimarães, Ricardo J P S; Freitas, Corina C; Dutra, Luciano V; Scholte, Ronaldo G C; Amaral, Ronaldo S; Drummond, Sandra C; Shimabukuro, Yosio E; Oliveira, Guilherme C; Carvalho, Omar S

2010-07-01

This paper analyses the associations between Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) on the prevalence of schistosomiasis and the presence of Biomphalaria glabrata in the state of Minas Gerais (MG), Brazil. Additionally, vegetation, soil and shade fraction images were created using a Linear Spectral Mixture Model (LSMM) from the blue, red and infrared channels of the Moderate Resolution Imaging Spectroradiometer spaceborne sensor and the relationship between these images and the prevalence of schistosomiasis and the presence of B. glabrata was analysed. First, we found a high correlation between the vegetation fraction image and EVI and second, a high correlation between soil fraction image and NDVI. The results also indicate that there was a positive correlation between prevalence and the vegetation fraction image (July 2002), a negative correlation between prevalence and the soil fraction image (July 2002) and a positive correlation between B. glabrata and the shade fraction image (July 2002). This paper demonstrates that the LSMM variables can be used as a substitute for the standard vegetation indices (EVI and NDVI) to determine and delimit risk areas for B. glabrata and schistosomiasis in MG, which can be used to improve the allocation of resources for disease control.

Techniques for investigation of an apparent outbreak of infections with Candida glabrata.

PubMed Central

Arif, S; Barkham, T; Power, E G; Howell, S A

1996-01-01

A cluster of Candida glabrata isolates recovered from seven patients in an intensive care unit over a 10-week period were compared with a collection of isolates from six epidemiologically distinct outpatients and a reference strain by several DNA typing methods. Restriction enzyme analysis with HinII distinguished 13 strains from the 14 sources and was the method of choice. Pulsed-field gel electrophoresis and random amplification of polymorphic DNA both detected nine types from the 14 sources; however, the results of these two methods did not always correlate. These methods demonstrated that five of the seven patients had distinguishable strains and that cross-infection was unlikely. PMID:8862586

The interaction of light and gravity on the transmission of Echinostoma caproni (Digenea: Echinostomatidae) cercariae to the second intermediate host, Biomphalaria glabrata (Gastropoda: Pulmonata).

PubMed

Platt, Thomas R; Greenlee, Hali; Zelmer, Derek A

2010-04-01

The current experiments were designed to assess the interaction of light and gravity on the transmission of Echinostoma caproni cercariae to the second intermediate host, Biomphalaria glabrata. Transmission chambers were constructed of clear polyvinyl chloride pipe covered with a black sleeve to exclude light. Snails were constrained within the chamber to prevent movement, while permitting the cercariae to swim freely. A trial consisted of 2 infected B. glabrata shedding E. caproni cercariae placed at the center of the chamber with 5 uninfected B. glabrata placed 10 cm above and below the shedding snails as sentinels. Three experiments, consisting of 12 trials each, were conducted under the following lighting conditions, i.e., above and below the transmission chamber, and in complete darkness. In all 3 experiments, the proportion of metacercariae was significantly higher in snails at the top of the chamber. The results suggest that a negative geotaxis is the primary factor in the initial dispersal of E. caproni cercariae. Coupling negative geotaxis and positive phototaxis (light from above) resulted in a significantly higher proportion of metacercariae in sentinel snails at the top of the transmission chamber when corrected for cercarial density. There was no significant difference in the proportion of metacercariae in snails at the top or bottom of the transmission chamber with light at the bottom of the chamber or in complete darkness. Cercariae of E. caproni only respond to light in context, i.e., from above, and ignore the light stimulus when it comes from an unexpected location (bottom of the water column). Significantly greater numbers of cercariae were released from shedding snails when light was present, suggesting that emergence of cercariae from B. glabrata is dependent on light regardless of the position of the light source.

Perennial peanut (Arachis glabrata Benth.) leaves contain hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase activity and accumulate hydroxycinnamoyl-tartaric acid esters

USDA-ARS?s Scientific Manuscript database

Many plants accumulate hydroxycinnamoyl esters to protect against abiotic and biotic stresses. Caffeoyl esters, in particular, can be substrates for endogenous polyphenol oxidases (PPOs). Recently, we showed that perennial peanut (Arachis glabrata Benth.) leaves contain PPO and identified one PPO su...

Chemical Composition of the Essential Oils from Leaves of Edible (Arachis hypogaea L.) and Perennial (Arachis glabrata Benth.) Peanut Plants

USDA-ARS?s Scientific Manuscript database

Peanuts or groundnuts (Arachis hypogaea L.) are a valuable oilseed crop, but other than the seed, the rest of the plant is of minimal value. Plant material including the leaves is used as mulch or as animal feed. Perennial peanut (Arachis glabrata Benth) known as forage or rhizoma peanut produces...

Susceptibility of Torulopsis glabrata in the presence of six antifungal agents determined by comparison of growth at several pHs.

PubMed

Darbord, J C; Vincent, F; Boutron, L; Goury, V; Guyomard, S

1987-03-01

We describe a method using an automated system whereby fungistatic activities can be determined in several conditions. The process was adapted to Torulopsis glabrata, and it showed that benzalkonium chloride, chlorhexidine gluconate, and thimerosal preserve fungistatic activities in acidic medium, whereas acidification reduces the activity of povidone iodine and poloxamer.

Simultaneous infection of Schistosoma mansoni and S. rodhaini in Biomphalaria glabrata: impact on chronobiology and cercarial behaviour

PubMed Central

Norton, Alice; Rollinson, David; Richards, Louisa; Webster, Joanne

2008-01-01

Background The chances of a schistosome cercaria encountering a suitable definitive host may be enhanced by emergence from the molluscan intermediate host with maximal glycogen stores and by an appropriate chronobiological rhythm. This study aimed to identify and characterize the effects of potential competitive interactions in the snail host Biomphalaria glabrata, between the closely-related Schistosoma mansoni and S. rodhaini, on phenotypic behavioural traits. It was predicted that inter-specific competition would affect chronobiological emergence rhythms and reduce the activity of schistosome swimming behavioural traits. Biomphalaria glabrata snails (120) were exposed to either S. mansoni or S. rodhaini single infections, or a mixed infection of both species simultaneously and the resulting cercarial phenotypic traits were characterised. Cercariae were identified from co-exposed snails by amplification and sequencing of the mitochondrial cytochrome oxidase subunit 1 (CO1). Results S. mansoni and S. rodhaini largely maintained their distinct chronobiological rhythms after mixed exposures and infections. However, inter-specific competition appeared to result in a restriction of the shedding pattern of S. rodhaini and slight shift in the shedding pattern of S. mansoni. Inter-specific competition also significantly lowered hourly cercarial production for both parasite species in comparison to single exposures and infections and reduced cercarial swimming activity. Conclusion Inter-specific competition was shown to influence cercarial production, chronobiology and activity and should therefore be investigated further in field situations to determine the effects of these changes on parasite fitness (incorporating both host finding and infectivity) where these two species overlap. Importantly this competition did not result in a large change in chronobiological emergence of cercariae for either species indicating that it would not have a large influence on the species

A Targeted Capture Linkage Map Anchors the Genome of the Schistosomiasis Vector Snail, Biomphalaria glabrata.

PubMed

Tennessen, Jacob A; Bollmann, Stephanie R; Blouin, Michael S

2017-07-05

The aquatic planorbid snail Biomphalaria glabrata is one of the most intensively-studied mollusks due to its role in the transmission of schistosomiasis. Its 916 Mb genome has recently been sequenced and annotated, but it remains poorly assembled. Here, we used targeted capture markers to map over 10,000 B. glabrata scaffolds in a linkage cross of 94 F1 offspring, generating 24 linkage groups (LGs). We added additional scaffolds to these LGs based on linkage disequilibrium (LD) analysis of targeted capture and whole-genome sequences of 96 unrelated snails. Our final linkage map consists of 18,613 scaffolds comprising 515 Mb, representing 56% of the genome and 75% of genic and nonrepetitive regions. There are 18 large (> 10 Mb) LGs, likely representing the expected 18 haploid chromosomes, and > 50% of the genome has been assigned to LGs of at least 17 Mb. Comparisons with other gastropod genomes reveal patterns of synteny and chromosomal rearrangements. Linkage relationships of key immune-relevant genes may help clarify snail-schistosome interactions. By focusing on linkage among genic and nonrepetitive regions, we have generated a useful resource for associating snail phenotypes with causal genes, even in the absence of a complete genome assembly. A similar approach could potentially improve numerous poorly-assembled genomes in other taxa. This map will facilitate future work on this host of a serious human parasite. Copyright © 2017 Tennessen et al.

Biochemical profile of Biomphalaria glabrata (Mollusca: Gastropoda) after infection by Echinostoma paraensei (Trematoda: Echinostomatidae).

PubMed

Tunholi, Victor M; Lustrino, Danilo; Tunholi-Alves, Vinícius M; Mello-Silva, Clélia C C; Maldonado, Arnaldo; Pinheiro, Jairo; Rodrigues, Maria de Lurdes de A

2011-09-01

The effect of infection by Echinostoma paraensei on the activity of the enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the concentration of total proteins, uric acid and urea in the hemolymph of Biomphalaria glabrata were investigated after exposure to five or 50 miracidia. The biochemical concentrations were measured weekly until the end of the fourth week after exposure. There was a significant decrease in the concentrations of total proteins in the snails exposed both to five and 50 miracidia, as well as an increase in the nitrogenous products of excretion, ALT and AST activities. The higher ALT activity in the hemolymph of the snails after infection with 50 miracidia suggests highest energetic requirement in these snails in relation to snails exposed to five miracidia. The results also suggest an increase in the use of total proteins, since there was increased formation of nitrogenous catabolites, in conformity with an increase in the aminotransferase activities, frequently associated with tissue damages. This can be explained by damage due to penetration by the miracidia and subsequent development of intramolluscan sporocysts and rediae.

[Influence of trematode invasion and zinc ions on the histometric peculiarities of haemocytes and some hematological indices of Planorbarius purpura (Gastropoda: Pulmonata: Bulinidae)].

PubMed

Kirichuk, G E; Stadnichenko, A P

2010-01-01

Cellular components of the Planorbarius purpura hemolymph are represented by three phyla of haemocytes (prohemocytes, eosinophilis microgranulocytes, and basophilis granulocytes) and vesicular cells. As a result of the invasions of P. purpura with the trematode Echinoparyphium aconiatum, changes of the linear dimensions of granular hemocytes and their nuclei took place. Moreover, an increase of the hemocytes' number per l mm3 of hemolymph and change of the percentages of different hemocyte types were recorded. Under the influence of zinc ions, linear dimensions of prohemocytes and their nuclei (at 10 MPCns of the toxicant) were changed. In granular hemocytes and abnormalities of all histometrical and hematological parameters were observed. All cytometrical, karyometrical, and hematological alterations were expressed more clearly in infested mollusks than in non-infested ones, and occurred usually under lower concentrations of zinc ions.

KRE5 Suppression Induces Cell Wall Stress and Alternative ER Stress Response Required for Maintaining Cell Wall Integrity in Candida glabrata

PubMed Central

Sasaki, Masato; Ito, Fumie; Aoyama, Toshio; Sato-Okamoto, Michiyo; Takahashi-Nakaguchi, Azusa; Chibana, Hiroji; Shibata, Nobuyuki

2016-01-01

The maintenance of cell wall integrity in fungi is required for normal cell growth, division, hyphae formation, and antifungal tolerance. We observed that endoplasmic reticulum stress regulated cell wall integrity in Candida glabrata, which possesses uniquely evolved mechanisms for unfolded protein response mechanisms. Tetracycline-mediated suppression of KRE5, which encodes a predicted UDP-glucose:glycoprotein glucosyltransferase localized in the endoplasmic reticulum, significantly increased cell wall chitin content and decreased cell wall β-1,6-glucan content. KRE5 repression induced endoplasmic reticulum stress-related gene expression and MAP kinase pathway activation, including Slt2p and Hog1p phosphorylation, through the cell wall integrity signaling pathway. Moreover, the calcineurin pathway negatively regulated cell wall integrity, but not the reduction of β-1,6-glucan content. These results indicate that KRE5 is required for maintaining both endoplasmic reticulum homeostasis and cell wall integrity, and that the calcineurin pathway acts as a regulator of chitin-glucan balance in the cell wall and as an alternative mediator of endoplasmic reticulum stress in C. glabrata. PMID:27548283

Deletion of the Candida glabrata ERG3 and ERG11 genes: effect on cell viability, cell growth, sterol composition, and antifungal susceptibility.

PubMed Central

Geber, A; Hitchcock, C A; Swartz, J E; Pullen, F S; Marsden, K E; Kwon-Chung, K J; Bennett, J E

1995-01-01

We have cloned and sequenced the structural genes encoding the delta 5,6 sterol desaturase (ERG3 gene) and the 14 alpha-methyl sterol demethylase (ERG11 gene) from Candida glabrata L5 (leu2). Single and double mutants of these genes were created by gene deletion. The phenotypes of these mutants, including sterol profiles, aerobic viabilities, antifungal susceptibilities, and generation times, were studied. Strain L5D (erg3 delta::LEU2) accumulated mainly ergosta-7,22-dien-3 beta-ol, was aerobically viable, and remained susceptible to antifungal agents but had a slower generation time than its parent strain. L5LUD (LEU2 erg11 delta::URA3) strains required medium supplemented with ergosterol and an anaerobic environment for growth. A spontaneous aerobically viable mutant, L5LUD40R (LEU erg11 delta::URA3), obtained from L5LUD (LEU2 erg11 delta::URA3), was found to accumulate lanosterol and obtusifoliol, was resistant to azole antifungal agents, demonstrated some increase in resistance to amphotericin B, and exhibited a 1.86-fold increase in generation time in comparison with L5 (leu2). The double-deletion mutant L5DUD61 (erg3 delta::LEU2 erg11 delta::URA3) was aerobically viable, produced mainly 14 alpha-methyl fecosterol, and had the same antifungal susceptibility pattern as L5LUD40R (LEU2 erg11 delta::URA3), and its generation time was threefold greater than that of L5 (leu2). Northern (RNA) analysis revealed that the single-deletion mutants had a marked increase in message for the undeleted ERG3 and ERG11 genes. These results indicate that differences in antifungal susceptibilities and the restoration of aerobic viability exist between the C. glabrata ergosterol mutants created in this study and those sterol mutants with similar genetic lesions previously reported for Saccharomyces cerevisiae. PMID:8593007

Carboxymethylated ɩ-carrageenan conjugated amphotericin B loaded gelatin nanoparticles for treating intracellular Candida glabrata infections.

PubMed

Aparna, V; Melge, Anu Rohit; Rajan, V K; Biswas, Raja; Jayakumar, R; Gopi Mohan, C

2018-04-15

Intercellular Candida glabrata infections are difficult to treat due to poor penetration of drugs into the fungal niche. Delivering amphotericin B (Amp B) into the macrophages where the pathogen inhabits is an effective solution. We are studying the macrophage targeting proficiency of ɩ-carrageenan for the delivery of Amp B using gelatin A nanoparticles (GNPs). The choice of gelatin A was the outcome of in silico inspections where the amino functionalized polymer having the best docking score with Amp B was selected. We prepared a sustained release formulation of amp B loaded carboxymethyl ɩ-carrageenan conjugated gelatin nanoparticles (CMC-Amp B-GNPs) with size 343±12nm and -25±5.3mV zeta potential. The formulations were found to be stable, biocompatible and non-haemolytic. Flow cytometry analysis showed 3 fold higher uptake of CMC-GNPs compared to the GNPs by RAW 264.7 cells. CMC-Amp B-GNPs showed enhanced antifungal activity than bare Amp B and Amp B-GNPs. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar-Perkinsus marinus.

PubMed

Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; Hégaret, Hélène; Sassi, Roberto; Farias, Natanael Dantas; Santana, Lucas Nunes; da Silva, Patricia Mirella

2017-06-01

Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4h) and long (48h and 7days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of cyanobacteria; while neither the WCs nor the ECPs modified phagocytosis of the biological particles, zymosan and P. marinus. Our results suggest a negative effect of cyanobacteria from the Synechocystis genus on host immune cells, in contrast to a more beneficial effect on the parasite cell, which

Comparison of genome engineering using the CRISPR-Cas9 system in C. glabrata wild-type and lig4 strains.

PubMed

Cen, Yuke; Timmermans, Bea; Souffriau, Ben; Thevelein, Johan M; Van Dijck, Patrick

2017-10-01

Candida glabrata is reported as the second most prevalent human opportunistic fungal pathogen in North America and is threatening patients all over the world. Its incidence is rising, while it has developed resistance to the most widely used antifungal drugs, necessitating new approaches based on better insight into the biology of the organism. Despite its close phylogenetic relationship with Saccharomyces cerevisiae, generating precise genomic alterations in this species is problematic. Previously we have shown that deletion of LIG4, which encodes an enzyme involved in Non-Homologous End Joining (NHEJ), strongly enhances the probability of obtaining correctly modified transformants. In this work we used the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR associated protein 9 (Cas9) system to genetically engineer the C. glabrata genome, targeting the genes ADE2, MET15 and SOK2, located on different chromosomes. We used the CRISPR-Cas9 technology to replace the open reading frame (ORF) by the SAT1 selective marker or introduced a premature stop codon in ADE2 and MET15, as they are easily scored by their adenine or methionine auxotrophy, respectively. The SOK2 gene was modified by insertion of a triple HA-tag sequence and the transformants were verified in a western blot. The CRISPR-Cas9 mediated targeting efficiency varies depending on the gene targeted and the genetic modification performed. We show that CRISPR-Cas9 mediated genome editing is more efficient than the conventional method in the wild-type strain, moreover it has the big advantage being marker-free. In previous work, we showed that the targeting efficiency is highly increased in the lig4Δ strain using the conventional way to delete genes in C. glabrata. Using the CRISPR-Cas9 system in this strain, the percentage of correct transformants is consistently higher compared to the wild-type strain. This indicates that using the lig4 mutant as such is already a strong

A paralogue of the phosphomutase-like gene family in Candida glabrata, CgPmu2, gained broad-range phosphatase activity due to a small number of clustered substitutions.

PubMed

Orlando, Kelly A; Iosue, Christine L; Leone, Sarah G; Davies, Danielle L; Wykoff, Dennis D

2015-10-15

Inorganic phosphate is required for a range of cellular processes, such as DNA/RNA synthesis and intracellular signalling. The phosphate starvation-inducible phosphatase activity of Candida glabrata is encoded by the gene CgPMU2 (C. glabrata phosphomutase-like protein). CgPMU2 is part of a three-gene family (∼75% identical) created through gene duplication in the C. glabrata clade; only CgPmu2 is a PHO-regulated broad range acid phosphatase. We identified amino acids that confer broad range phosphatase activity on CgPmu2 by creating fusions of sections of CgPMU2 with CgPMU1, a paralogue with little broad range phosphatase activity. We used site-directed mutagenesis on various fusions to sequentially convert CgPmu1 to CgPmu2. Based on molecular modelling of the Pmu proteins on to a histidine phosphatase crystal structure, clusters of amino acids were found in two distinct regions that were able to confer phosphatase activity. Substitutions in these two regions together conferred broad phosphatase activity on CgPmu1. Interestingly, one change is a histidine adjacent to the active site histidine of CgPmu2 and it exhibits a novel ability to partially replace the conserved active site histidine in CgPmu2. Additionally, a second amino acid change was able to confer nt phosphatase activity to CgPmu1, suggesting single amino acid changes neofunctionalize CgPmu2. © 2015 Authors; published by Portland Press Limited.

Controlled Chaos of Polymorphic Mucins in a Metazoan Parasite (Schistosoma mansoni) Interacting with Its Invertebrate Host (Biomphalaria glabrata)

PubMed Central

Roger, Emmanuel; Grunau, Christoph; Pierce, Raymond J.; Hirai, Hirohisa; Gourbal, Benjamin; Galinier, Richard; Emans, Rémi; Cesari, Italo M.; Cosseau, Céline; Mitta, Guillaume

2008-01-01

Invertebrates were long thought to possess only a simple, effective and hence non-adaptive defence system against microbial and parasitic attacks. However, recent studies have shown that invertebrate immunity also relies on immune receptors that diversify (e.g. in echinoderms, insects and mollusks (Biomphalaria glabrata)). Apparently, individual or population-based polymorphism-generating mechanisms exists that permit the survival of invertebrate species exposed to parasites. Consequently, the generally accepted arms race hypothesis predicts that molecular diversity and polymorphism also exist in parasites of invertebrates. We investigated the diversity and polymorphism of parasite molecules (Schistosoma mansoni Polymorphic Mucins, SmPoMucs) that are key factors for the compatibility of schistosomes interacting with their host, the mollusc Biomphalaria glabrata. We have elucidated the complex cascade of mechanisms acting both at the genomic level and during expression that confer polymorphism to SmPoMuc. We show that SmPoMuc is coded by a multi-gene family whose members frequently recombine. We show that these genes are transcribed in an individual-specific manner, and that for each gene, multiple splice variants exist. Finally, we reveal the impact of this polymorphism on the SmPoMuc glycosylation status. Our data support the view that S. mansoni has evolved a complex hierarchical system that efficiently generates a high degree of polymorphism—a “controlled chaos”—based on a relatively low number of genes. This contrasts with protozoan parasites that generate antigenic variation from large sets of genes such as Trypanosoma cruzi, Trypanosoma brucei and Plasmodium falciparum. Our data support the view that the interaction between parasites and their invertebrate hosts are far more complex than previously thought. While most studies in this matter have focused on invertebrate host diversification, we clearly show that diversifying mechanisms also exist on

Comparative assessment of cardiac activity and DNA damage in haemocytes of the Mediterranean mussel Mytilus galloprovincialis in exposure to tributyltin chloride.

PubMed

Martinović, Rajko; Kolarević, Stoimir; Kračun-Kolarević, Margareta; Kostić, Jovana; Jokanović, Sandra; Gačić, Zoran; Joksimović, Danijela; Đurović, Mirko; Kljajić, Zoran; Vuković-Gačić, Branka

2016-10-01

This study gives an insight in sensitivity of heart rate (Hr) of Mytilus galloprovincialis as a physiological biomarker. Impact of tributyltin chloride (TBT-Cl) on Hr was studied in parallel with evaluation of mutagenic, genotoxic and cytotoxic potential of TBT-Cl (10, 100 and 1000μg/L) within 96h treatment in static conditions. Mutagenic potential was assessed by SOS/umuC assay while genotoxicity was assessed in haemocytes of M. galloprovincialis by using the comet assay and the micronucleus test. Benzo(a)pyrene (B(a)P) was used as a positive control. Hr variations detected in TBT-Cl treatments can be linked to data obtained in the genotoxicological assays indicating that Hr can be considered and used as a reliable physiological biomarker for detecting the presence of organotin compounds. However despite the observed genotoxic potential of B(a)P, a noteworthy Hr response was not observed which further questions the potential of Hr in the detection of different types of pollutants. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular characterization of the silencing complex SIR in Candida glabrata hyperadherent clinical isolates.

PubMed

Leiva-Peláez, Osney; Gutiérrez-Escobedo, Guadalupe; López-Fuentes, Eunice; Cruz-Mora, José; De Las Peñas, Alejandro; Castaño, Irene

2018-05-29

An important virulence factor for the fungal pathogen Candida glabrata is the ability to adhere to the host cells, which is mediated by the expression of adhesins. Epa1 is responsible for ∼95% of the in vitro adherence to epithelial cells and is the founding member of the Epa family of adhesins. The majority of EPA genes are localized close to different telomeres, which causes transcriptional repression due to subtelomeric silencing. In C. glabrata there are three Sir proteins (Sir2, Sir3 and Sir4) that are essential for subtelomeric silencing. Among a collection of 79 clinical isolates, some display a hyperadherent phenotype to epithelial cells compared to our standard laboratory strain, BG14. These isolates also express several subtelomeric EPA genes simultaneously. We cloned the SIR2, SIR3 and SIR4 genes from the hyperadherent isolates and from the BG14 and the sequenced strain CBS138 in a replicative vector to complement null mutants in each of these genes in the BG14 background. All the SIR2 and SIR4 alleles tested from selected hyper-adherent isolates were functional and efficient to silence a URA3 reporter gene inserted in a subtelomeric region. The SIR3 alleles from these isolates were also functional, except the allele from isolate MC2 (sir3-MC2), which was not functional to silence the reporter and did not complement the hyperadherent phenotype of the BG14 sir3Δ. Consistently, sir3-MC2 allele is recessive to the SIR3 allele from BG14. Sir3 and Sir4 alleles from the hyperadherent isolates contain several polymorphisms and two of them are present in all the hyperadherent isolates analyzed. Instead, the Sir3 and Sir4 alleles from the BG14 and another non-adherent isolate do not display these polymorphisms and are identical to each other. The particular combination of polymorphisms in sir3-MC2 and in SIR4-MC2 could explain in part the hyperadherent phenotype displayed by this isolate. Copyright © 2018 Elsevier Inc. All rights reserved.

Global Analysis of the Evolution and Mechanism of Echinocandin Resistance in Candida glabrata

PubMed Central

Singh-Babak, Sheena D.; Babak, Tomas; Diezmann, Stephanie; Hill, Jessica A.; Xie, Jinglin Lucy; Chen, Ying-Lien; Poutanen, Susan M.; Rennie, Robert P.; Heitman, Joseph; Cowen, Leah E.

2012-01-01

The evolution of drug resistance has a profound impact on human health. Candida glabrata is a leading human fungal pathogen that can rapidly evolve resistance to echinocandins, which target cell wall biosynthesis and are front-line therapeutics for Candida infections. Here, we provide the first global analysis of mutations accompanying the evolution of fungal drug resistance in a human host utilizing a series of C. glabrata isolates that evolved echinocandin resistance in a patient treated with the echinocandin caspofungin for recurring bloodstream candidemia. Whole genome sequencing identified a mutation in the drug target, FKS2, accompanying a major resistance increase, and 8 additional non-synonymous mutations. The FKS2-T1987C mutation was sufficient for echinocandin resistance, and associated with a fitness cost that was mitigated with further evolution, observed in vitro and in a murine model of systemic candidemia. A CDC6-A511G(K171E) mutation acquired before FKS2-T1987C(S663P), conferred a small resistance increase. Elevated dosage of CDC55, which acquired a C463T(P155S) mutation after FKS2-T1987C(S663P), ameliorated fitness. To discover strategies to abrogate echinocandin resistance, we focused on the molecular chaperone Hsp90 and downstream effector calcineurin. Genetic or pharmacological compromise of Hsp90 or calcineurin function reduced basal tolerance and resistance. Hsp90 and calcineurin were required for caspofungin-dependent FKS2 induction, providing a mechanism governing echinocandin resistance. A mitochondrial respiration-defective petite mutant in the series revealed that the petite phenotype does not confer echinocandin resistance, but renders strains refractory to synergy between echinocandins and Hsp90 or calcineurin inhibitors. The kidneys of mice infected with the petite mutant were sterile, while those infected with the HSP90-repressible strain had reduced fungal burden. We provide the first global view of mutations accompanying the

Detection of early effects of a single herbicide (diuron) and a mix of herbicides and pharmaceuticals (diuron, isoproturon, ibuprofen) on immunological parameters of Pacific oyster (Crassostrea gigas) spat.

PubMed

Luna-Acosta, A; Renault, T; Thomas-Guyon, H; Faury, N; Saulnier, D; Budzinski, H; Le Menach, K; Pardon, P; Fruitier-Arnaudin, I; Bustamante, P

2012-06-01

In the context of massive summer mortality events of the Pacific oyster Crassostrea gigas, the aim of this study was to investigate the early effects on genes, enzymes and haemocyte parameters implicated in immune defence mechanisms in C. gigas oysters exposed to a potentially hostile environment, i.e. to an herbicide alone or within a mixture. Following 2 h of exposure to the herbicide diuron at 1 μg L(-1), the repression of different genes implicated in immune defence mechanisms in the haemocytes and the inhibition of enzyme activities, such as laccase-type phenoloxidase (PO) in the plasma, were observed. The inhibition of superoxide dismutase (SOD) activity in the plasma was also observed after 6 and 24 h of exposure. In the mixture with the herbicides diuron and isoproturon, and the pharmaceutical ibuprofen, catecholase-type PO activity in the plasma and the percentage of phagocytosis in the haemocytes were reduced after 6 h of exposure. Our results showed that early effects on molecular, biochemical and cellular parameters can be detected in the presence of diuron alone or within a mixture, giving an insight of its potential effect in situations that can be found in natural environments, i.e. relatively high concentrations for short periods of time. Copyright © 2012 Elsevier Ltd. All rights reserved.

Haematopoiesis in molluscs: a review of haemocyte development and function in gastropods, cephalopods and bivalves

PubMed Central

Pila, EA; Sullivan, JT; Wu, XZ; Fang, J; Rudko, SP; Gordy, MA; Hanington, PC

2015-01-01

Haematopoiesis is a process that is responsible for generating sufficient numbers of blood cells in the circulation and in tissues. It is central to maintenance of homeostasis within an animal, and is critical for defense against infection. While haematopoiesis is common to all animals possessing a circulatory system, the specific mechanisms and ultimate products of haematopoietic events vary greatly. Our understanding of this process in non-vertebrate organisms is primarily derived from those species that serve as developmental and immunological models, with sparse investigations having been carried out in other organisms spanning the metazoa. As research into the regulation of immune and blood cell development advances, we have begun to gain insight into haematopoietic events in a wider array of animals, including the molluscs. What began in the early 1900’s as observational studies on the morphological characteristics of circulating immune cells has now advanced to mechanistic investigations of the cytokines, growth factors, receptors, signalling pathways, and patterns of gene expression that regulate molluscan haemocyte development. Emerging is a picture of an incredible diversity of developmental processes and outcomes that parallels the biological diversity observed within the different classes of the phylum Mollusca. However, our understanding of haematopoiesis in molluscs stems primarily from the three most-studied classes, the Gastropoda, Cephalopoda and Bivalvia. While these represent perhaps the molluscs of greatest economic and medical importance, the fact that our information is limited to only 3 of the 9 extant classes in the phylum highlights the need for further investigation in this area. In this review, we summarize the existing literature that defines haematopoiesis and its products in gastropods, cephalopods and bivalves. PMID:26592965

Haematopoiesis in molluscs: A review of haemocyte development and function in gastropods, cephalopods and bivalves.

PubMed

Pila, E A; Sullivan, J T; Wu, X Z; Fang, J; Rudko, S P; Gordy, M A; Hanington, P C

2016-05-01

Haematopoiesis is a process that is responsible for generating sufficient numbers of blood cells in the circulation and in tissues. It is central to maintenance of homeostasis within an animal, and is critical for defense against infection. While haematopoiesis is common to all animals possessing a circulatory system, the specific mechanisms and ultimate products of haematopoietic events vary greatly. Our understanding of this process in non-vertebrate organisms is primarily derived from those species that serve as developmental and immunological models, with sparse investigations having been carried out in other organisms spanning the metazoa. As research into the regulation of immune and blood cell development advances, we have begun to gain insight into haematopoietic events in a wider array of animals, including the molluscs. What began in the early 1900's as observational studies on the morphological characteristics of circulating immune cells has now advanced to mechanistic investigations of the cytokines, growth factors, receptors, signalling pathways, and patterns of gene expression that regulate molluscan haemocyte development. Emerging is a picture of an incredible diversity of developmental processes and outcomes that parallels the biological diversity observed within the different classes of the phylum Mollusca. However, our understanding of haematopoiesis in molluscs stems primarily from the three most-studied classes, the Gastropoda, Cephalopoda and Bivalvia. While these represent perhaps the molluscs of greatest economic and medical importance, the fact that our information is limited to only 3 of the 9 extant classes in the phylum highlights the need for further investigation in this area. In this review, we summarize the existing literature that defines haematopoiesis and its products in gastropods, cephalopods and bivalves. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of synergistic anticandidal and apoptotic effects of ferulic acid and caspofungin against Candida albicans.

PubMed

Canturk, Zerrin

2018-01-01

This study aimed to investigate the synergy between anticandidal and apoptotic effects of ferulic acid and caspofungin against Candida albicans and Candida glabrata, with the help of a quantitative checkerboard microdilution assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) as a viability dye. Apoptotic effects of caspofungin and ferulic acid concentrations (alone and combined) were analyzed for C. albicans and C. glabrata based on annexin V-propidium iodide binding capacities using flow cytometric analysis. C. albicans showed a synergistic effect, represented by a fractional inhibitory concentration index of < 0.5, but C. glabrata showed no synergistic effect (fractional inhibitory concentration index > 0.5). Early and late apoptotic effects of caspofungin and ferulic acid concentrations (1 μg/mL and 1000 μg/mL) were calculated as 55.7% and 18.3%, respectively, while their necrotic effects were determined as 5.8% and 51.6%, respectively, using flow cytometric analyses. The apoptotic effects of the combination of caspofungin and ferulic acid at concentrations of 1 μg/mL and 1000 μg/mL on C. albicans and C. glabrata were 73.0% and 48.7%, respectively. Ferulic acid also demonstrated a synergistic effect in combination with caspofungin against C. albicans. Another possibility is to combine the existing anticandidal drug with phytochemicals to enhance the efficacy of anticandidal drug. Copyright © 2017. Published by Elsevier B.V.

Circulating Biomphalaria glabrata hemocyte subpopulations possess shared schistosome glycans and receptors capable of binding larval glycoconjugates

PubMed Central

Yoshino, Timothy P.; Wu, Xiao-Jun; Gonzalez, Laura A.; Hokke, Cornelis H.

2013-01-01

Host lectin-like recognition molecules may play an important role in innate resistance in Biomphalaria glabrata snails to larval schistosome infection, thus implicating parasite-expressed glycans as putative ligands for these lectin receptors. While host lectins may utilize specific glycan structures for parasite recognition, it also has been hypothesized that the parasite may use this system to evade immune detection by mimicking naturally-expressed host glycans, resulting in reduced immunorecognition capacity. By employing immunocytochemical (ICC) and Western blot assays using schistosome glycan-specific monoclonal antibodies (mABs) we sought to identify specific glycan epitopes (glycotopes) shared in common between larval S. mansoni and B. glabrata hemocytes, the primary immune effector cells in snails. Results confirmed the presence of selected larval glycotopes on subpopulations of hemocytes by ICC and association with numerous hemocyte proteins by Western blot analyses, including a trimannosyl core N-glycan (TriMan), and two fucosylated lacdiNAc (LDN) variants, F-LDN and F-LDN-F. Snail strain differences were seen in the prevalence of constitutively expressed F-LDN on hemocytes, and in the patterns of protein immunoreactivity with these mABs. In contrast, there was little to no hemocyte reactivity with mABs for Lewis X (LeX), LDN, LDN-F or LDN-DF. When intact hemocytes were exposed to larval transformation products (LTPs), distinct cell subpopulations displayed weak (LeX, LDN-DF) to moderate (LDN, LDN-F) glycotope reactivity by ICC, including snail strain differences in the prevalence of LDN-reactive cellular subsets. Far-Western blot analyses of the hemocytes following exposure to larval transformation proteins (LTPs) also revealed multiple mAB-reactive hemocyte protein bands for LeX, LDN, LDN-F, and LDN-DF. These results demonstrate the existence of complex patterns of shared larval glycan constitutively expressed on hemocytes and their proteins, as well as

Overcoming the heterologous bias: An in vivo functional analysis of multidrug efflux transporter, CgCdr1p in matched pair clinical isolates of Candida glabrata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puri, Nidhi; Manoharlal, Raman; Sharma, Monika

2011-01-07

Research highlights: {yields} First report to demonstrate an in vivo expression system of an ABC multidrug transporter CgCdr1p of C. glabrata. {yields} First report on the structure and functional characterization of CgCdr1p. {yields} Functional conservation of divergent but typical residues of CgCdr1p. {yields} CgCdr1p elicits promiscuity towards substrates and has a large drug binding pocket with overlapping specificities. -- Abstract: We have taken advantage of the natural milieu of matched pair of azole sensitive (AS) and azole resistant (AR) clinical isolates of Candida glabrata for expressing its major ABC multidrug transporter, CgCdr1p for structure and functional analysis. This was accomplishedmore » by tagging a green fluorescent protein (GFP) downstream of ORF of CgCDR1 and integrating the resultant fusion protein at its native chromosomal locus in AS and AR backgrounds. The characterization confirmed that in comparison to AS isolate, CgCdr1p-GFP was over-expressed in AR isolates due to its hyperactive native promoter and the GFP tag did not affect its functionality in either construct. We observed that in addition to Rhodamine 6 G (R6G) and Fluconazole (FLC), a recently identified fluorescent substrate of multidrug transporters Nile Red (NR) could also be expelled by CgCdr1p. Competition assays with these substrates revealed the presence of overlapping multiple drug binding sites in CgCdr1p. Point mutations employing site directed mutagenesis confirmed that the role played by unique amino acid residues critical to ATP catalysis and localization of ABC drug transporter proteins are well conserved in C. glabrata as in other yeasts. This study demonstrates a first in vivo novel system where over-expression of GFP tagged MDR transporter protein can be driven by its own hyperactive promoter of AR isolates. Taken together, this in vivo system can be exploited for the structure and functional analysis of CgCdr1p and similar proteins wherein the arte

Facultative Sterol Uptake in an Ergosterol-Deficient Clinical Isolate of Candida glabrata Harboring a Missense Mutation in ERG11 and Exhibiting Cross-Resistance to Azoles and Amphotericin B

PubMed Central

Hull, Claire M.; Parker, Josie E.; Bader, Oliver; Weig, Michael; Gross, Uwe; Warrilow, Andrew G. S.; Kelly, Diane E.

2012-01-01

We identified a clinical isolate of Candida glabrata (CG156) exhibiting flocculent growth and cross-resistance to fluconazole (FLC), voriconazole (VRC), and amphotericin B (AMB), with MICs of >256, >256, and 32 μg ml−1, respectively. Sterol analysis using gas chromatography-mass spectrometry (GC-MS) revealed that CG156 was a sterol 14α-demethylase (Erg11p) mutant, wherein 14α-methylated intermediates (lanosterol was >80% of the total) were the only detectable sterols. ERG11 sequencing indicated that CG156 harbored a single-amino-acid substitution (G315D) which nullified the function of native Erg11p. In heterologous expression studies using a doxycycline-regulatable Saccharomyces cerevisiae erg11 strain, wild-type C. glabrata Erg11p fully complemented the function of S. cerevisiae sterol 14α-demethylase, restoring growth and ergosterol synthesis in recombinant yeast; mutated CG156 Erg11p did not. CG156 was culturable using sterol-free, glucose-containing yeast minimal medium (glcYM). However, when grown on sterol-supplemented glcYM (with ergosta 7,22-dienol, ergosterol, cholestanol, cholesterol, Δ7-cholestenol, or desmosterol), CG156 cultures exhibited shorter lag phases, reached higher cell densities, and showed alterations in cellular sterol composition. Unlike comparator isolates (harboring wild-type ERG11) that became less sensitive to FLC and VRC when cultured on sterol-supplemented glcYM, facultative sterol uptake by CG156 did not affect its azole-resistant phenotype. Conversely, CG156 grown using glcYM with ergosterol (or with ergosta 7,22-dienol) showed increased sensitivity to AMB; CG156 grown using glcYM with cholesterol (or with cholestanol) became more resistant (MICs of 2 and >64 μg AMB ml−1, respectively). Our results provide insights into the consequences of sterol uptake and metabolism on growth and antifungal resistance in C. glabrata. PMID:22615281

Lab-scale preparations of Candida albicans and dual Candida albicans-Candida glabrata biofilms on the surface of medical-grade polyvinyl chloride (PVC) perfusion tube using a modified gravity-supported free-flow biofilm incubator (GS-FFBI).

PubMed

Shao, Jing; Lu, KeQiao; Tian, Ge; Cui, YanYan; Yan, YuanYuan; Wang, TianMing; Zhang, XinLong; Wang, ChangZhong

2015-02-01

The assembly of a man-made gravity-supported free-flow biofilm incubator (GS-FFBI) was described, which was composed of a gas cushion injector and four incubators. The GS-FFBI had the characteristics of (i) a bottom-up flow direction, and (ii) lab-scale biofilm preparation without the use of a multichannel pump. Two opportunistic fungal strains, namely Candida albicans and Candida glabrata, were employed to incubate C. albicans and dual C. albicans-C. glabrata biofilms on the surface of medical-grade polyvinyl chloride perfusion tube. In terms of the results from {2, 3-bis (2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide} (XTT) assay, dry weight measurement, colony-forming unit counting, susceptibility test, and scanning electron microscopy, it was demonstrated that GS-FFBI could form both stable single and dual Candida biofilms with no significant variations among the four incubators or the three daily incubations within 21h, and could operate for at least 96h smoothly with no contamination of stock medium. The results also indicated, for the first time, that C. albicans and C. glabrata might be co-existent competitively and symbiotically in the dual biofilms with flowing media. GS-FFBI would be a useful device to study in vitro morphological and physiological features of microbial biofilms in the medical settings. Copyright © 2014 Elsevier B.V. All rights reserved.

Redistribution of carbon flux in Torulopsis glabrata by altering vitamin and calcium level.

PubMed

Liu, Liming; Li, Yin; Zhu, Yang; Du, Guocheng; Chen, Jian

2007-01-01

Manipulation of cofactor (thiamine, biotin and Ca(2+)) levels as a potential tool to redistribute carbon flux was studied in Torulopsis glabrata. With sub-optimization of vitamin in fermentation medium, the carbon flux was blocked at the key node of pyruvate, and 69 g/L pyruvate was accumulated. Increasing the concentrations of thiamine and biotin could selectively open the valve of carbon flux from pyruvate to pyruvate dehydrogenase complex, the pyruvate carboxylase (PC) pathway and the channel into the TCA cycle, leading to the over-production of alpha-ketoglutarate. In addition, the activity of PC was enhanced with Ca(2+) present in fermentation medium. By combining high concentration's vitamins and CaCO(3) as the pH buffer, a batch culture was conducted in a 7-L fermentor, with the pyruvate concentration decreased to 21.8 g/L while alpha-ketoglutarate concentration increased to 43.7 g/L. Our study indicated that the metabolic flux could be redistributed to overproduce desired metabolites with manipulating the cofactor levels. Furthermore, the manipulation of vitamin level provided an alternative tool to realize metabolic engineering goals.

Altered Gene Expression in the Schistosome-Transmitting Snail Biomphalaria glabrata following Exposure to Niclosamide, the Active Ingredient in the Widely Used Molluscicide Bayluscide

PubMed Central

Zhang, Si-Ming; Buddenborg, Sarah K.; Adema, Coen M.; Sullivan, John T.; Loker, Eric S.

2015-01-01

In view of the call by the World Health Organization (WHO) for elimination of schistosomiasis as a public health problem by 2025, use of molluscicides in snail control to supplement chemotherapy–based control efforts is likely to increase in the coming years. The mechanisms of action of niclosamide, the active ingredient in the most widely used molluscicides, remain largely unknown. A better understanding of its toxicology at the molecular level will both improve our knowledge of snail biology and may offer valuable insights into the development of better chemical control methods for snails. We used a recently developed Biomphalaria glabrata oligonucleotide microarray (31K features) to investigate the effect of sublethal exposure to niclosamide on the transcriptional responses of the snail B. glabrata relative to untreated snails. Most of the genes highly upregulated following exposure of snails to niclosamide are involved in biotransformation of xenobiotics, including genes encoding cytochrome P450s (CYP), glutathione S-transferases (GST), and drug transporters, notably multi-drug resistance protein (efflux transporter) and solute linked carrier (influx transporter). Niclosamide also induced stress responses. Specifically, six heat shock protein (HSP) genes from three super-families (HSP20, HSP40 and HSP70) were upregulated. Genes encoding ADP-ribosylation factor (ARF), cAMP response element-binding protein (CREB) and coatomer, all of which are involved in vesicle trafficking in the Golgi of mammalian cells, were also upregulated. Lastly, a hemoglobin gene was downregulated, suggesting niclosamide may affect oxygen transport. Our results show that snails mount substantial responses to sublethal concentrations of niclosamide, at least some of which appear to be protective. The topic of how niclosamide’s lethality at higher concentrations is determined requires further study. Given that niclosamide has also been used as an anthelmintic drug for decades and has

Altered Gene Expression in the Schistosome-Transmitting Snail Biomphalaria glabrata following Exposure to Niclosamide, the Active Ingredient in the Widely Used Molluscicide Bayluscide.

PubMed

Zhang, Si-Ming; Buddenborg, Sarah K; Adema, Coen M; Sullivan, John T; Loker, Eric S

2015-01-01

In view of the call by the World Health Organization (WHO) for elimination of schistosomiasis as a public health problem by 2025, use of molluscicides in snail control to supplement chemotherapy-based control efforts is likely to increase in the coming years. The mechanisms of action of niclosamide, the active ingredient in the most widely used molluscicides, remain largely unknown. A better understanding of its toxicology at the molecular level will both improve our knowledge of snail biology and may offer valuable insights into the development of better chemical control methods for snails. We used a recently developed Biomphalaria glabrata oligonucleotide microarray (31K features) to investigate the effect of sublethal exposure to niclosamide on the transcriptional responses of the snail B. glabrata relative to untreated snails. Most of the genes highly upregulated following exposure of snails to niclosamide are involved in biotransformation of xenobiotics, including genes encoding cytochrome P450s (CYP), glutathione S-transferases (GST), and drug transporters, notably multi-drug resistance protein (efflux transporter) and solute linked carrier (influx transporter). Niclosamide also induced stress responses. Specifically, six heat shock protein (HSP) genes from three super-families (HSP20, HSP40 and HSP70) were upregulated. Genes encoding ADP-ribosylation factor (ARF), cAMP response element-binding protein (CREB) and coatomer, all of which are involved in vesicle trafficking in the Golgi of mammalian cells, were also upregulated. Lastly, a hemoglobin gene was downregulated, suggesting niclosamide may affect oxygen transport. Our results show that snails mount substantial responses to sublethal concentrations of niclosamide, at least some of which appear to be protective. The topic of how niclosamide's lethality at higher concentrations is determined requires further study. Given that niclosamide has also been used as an anthelmintic drug for decades and has been

Schistosoma mansoni infection of juvenile Biomphalaria glabrata induces a differential stress response between resistant and susceptible snails.

PubMed

Ittiprasert, Wannaporn; Nene, Rahul; Miller, André; Raghavan, Nithya; Lewis, Fred; Hodgson, Jacob; Knight, Matty

2009-11-01

Schistosomes develop successfully in susceptible snails but are encapsulated and killed in resistant ones. Mechanism(s) shaping these outcomes involves the parasites ability to evade the snail's defenses. RNA analysis from resistant (BS-90), non-susceptible (LAC2) and susceptible (NMRI) juvenile Biomphalaria glabrata to Schistosoma mansoni revealed that stress-related genes, heat shock protein 70 (Hsp 70) and reverse transcriptase (RT), were dramatically co-induced early in susceptible snails, but not in resistant/non-susceptible ones. These transcripts were, however, down regulated upon exposure to irradiated parasites although penetration behavior of irradiated vs. normal parasites were the same, indicating that Hsp 70 and RT regulation was elicited by infection and not injury. Understanding molecular events involved in stress response transcriptional regulation of Hsp 70 in juvenile snails could pave a way towards the identification of genes involved in schistosome/snail interactions.

Reduction in transmission of Schistosoma mansoni by a four-year focal mollusciciding programme against Biomphalaria glabrata in Saint Lucia.

PubMed

Prentice, M A; Jordan, P; Bartholomew, R K; Grist, E

1981-01-01

The effect of transmission of Schistosoma mansoni of a focal snail control programme was investigated over four years amongst approximately 1250 people living in five communities in the steep-sided Soufriere river valley, St. Lucia, West Indies. Bayer 6076 was applied from constant flow drip cans to 12 stream sections at a target dose of 8 mg/litre clonitralide every four weeks. Only proven and potential transmission sites were treated; marsh habitats, where Biomphalaria glabrata were widespread, were ignored. In the stream snail numbers were reduced by 94% in the first year and by 100% thereafter. Incidence of new S. mansoni infections amongst children fell from 18% in the last year before control to 6% and 9% after three and four years respectively. Amongst children and adults in the four years of control the conversion/reversion ratio declined leading to a lowering of the over-all prevalence from 40% to 22%. Parasitologically the results were similar to those of a previously evaluated area-wide mollusciciding programme. The mean annual cost per person protected was US $2.60. This figure is atypically high because the topography of the area severely limited the population size.

Endoscopic Endonasal Transsphenoidal Drainage of a Spontaneous Candida glabrata Pituitary Abscess.

PubMed

Strickland, Ben A; Pham, Martin; Bakhsheshian, Joshua; Carmichael, John; Weiss, Martin; Zada, Gabriel

2018-01-01

Noniatrogenic pituitary abscess remains a rare clinical entity, and is the indication for surgery in <1% of transsphenoidal approaches. Correct diagnosis of this rare entity is often delayed. Without timely treatment, morbidity and mortality are high. Of the 200 cases reported to date, less than one-half have identified a causative organism. We report the second case of a pituitary abscess caused by Candida species, and also provide an intraoperative video showing the endoscopic management of this pathology. A 33-year-old woman presented with headache, hypopituitarism, and vision loss in the setting of diabetic ketoacidosis, and was found to have multiple abscesses in the liver, lung, kidney, and uterus. Brain magnetic resonance imaging revealed a 15-mm cystic sellar mass with restricted diffusion. The patient underwent urgent evacuation of the abscess via an endoscopic endonasal transsphenoidal route, with obvious purulent material filling the sella, later identified as Candida glabrata. Antimicrobial therapy was refined appropriately, and she exhibited significant improvement in neurologic function, although endocrinopathy has persisted. With timely management, including a combination of surgical drainage and appropriate antimicrobial therapy, neurologic outcomes are good in most cases of pituitary abscess; however, endocrinopathy often does not improve. Although most reported cases with identified causative organisms speciate bacteria, some cases are of fungal etiology and require different antimicrobial agents. This further underscores the importance of identifying the causative agent. Copyright © 2017 Elsevier Inc. All rights reserved.

Schistosoma mansoni miracidia transformed by particle bombardment infect Biomphalaria glabrata snails and develop into transgenic sporocysts.

PubMed

Heyers, Oliver; Walduck, Anna K; Brindley, Paul J; Bleiss, Wilfrid; Lucius, Richard; Dorbic, Tomislav; Wittig, Burghardt; Kalinna, Bernd H

2003-10-01

Miracidia (and adults) of Schistosoma mansoni which had been subjected to particle bombardment with a plasmid DNA encoding enhanced green fluorescent protein (EGFP) under control of the S. mansoni heat shock protein 70 (HSP70) promoter and termination elements were shown to express the reporter gene. Bombarded miracidia were able to penetrate and establish in Biomphalaria glabrata the intermediate host snail. Gold particles could be detected in the germ balls of parasites in paraffin-sections of snail tissue. The bombarded miracidia were able to develop normally and to transform into mother sporocysts. Reporter gene activity could be determined at 10 days post-infection by RT-PCR in snail tissues, but not by microscopy or Western blot which probably reflected sub-optimal expression levels of constructs. Our findings indicated that it is feasible to return transgenic miracidia to the life cycle, a crucial step for the establishment of a transgenesis system for schistosomes.

Effect of Lactobacillus rhamnosus on the response of Galleria mellonella against Staphylococcus aureus and Escherichia coli infections.

PubMed

Jorjão, Adeline Lacerda; de Oliveira, Felipe Eduardo; Leão, Mariella Vieira Pereira; Jorge, Antonio Olavo Cardoso; de Oliveira, Luciane Dias

2018-04-01

This study evaluated the prophylactic effects of the live or heat-killed probiotic strain Lactobacillus rhamnosus ATCC 7469 in Galleria mellonella, inoculated with Staphylococcus aureus or Escherichia coli. L. rhamnosus suspension was prepared and a part of it was autoclaved to obtain heat-killed lactobacilli. The larvae were inoculated of these suspensions and pathogenic. The survival of the larvae was observed during 7 days and after 24 h of inoculation haemocytes counted, melanization and nitric oxide production were analyzed. Larvae survival rate increased in the group inoculated with heat-killed L. rhamnosus, however, with no statistical difference. There was a significant increase in total haemocyte counts in all test groups. Haemolymph melanization and nitric oxide production were higher in the group inoculated with L. rhamnosus and infected with S. aureus. It was concluded that, in this model of infection, heat-killed L. rhamnosus ATCC 7469 promoted greater protection in Galleria mellonella infected with S. aureus or E. coli.

Characterization of immune genes from the schistosome host snail Biomphalaria glabrata that encode peptidoglycan recognition proteins and gram-negative bacteria binding protein

PubMed Central

Zeng, Yong; Loker, Eric S.

2013-01-01

Peptidoglycan (PGN) recognition proteins (PGRPs) and gram-negative bacteria binding proteins (GNBPs) play an essential role in Toll/Imd signaling pathways in arthropods. The existence of homologous pathways involving PGRPs and GNBPs in other major invertebrate phyla such as the Mollusca remains unclear. In this paper, we report four full-length PGRP cDNAs and one full-length GNBP cDNA cloned from the snail Biomphalaria glabrata, the intermediate host of the human blood fluke Schistosoma mansoni, designated as BgPGRPs and BgGNBP, respectively. Three transcripts are generated from a long form PGRP gene (BgPGRP-LA) by alternative splicing and one from a short form PGRP gene (BgPGRP-SA). BgGNBP encodes a putative secreted protein. Northern blots demonstrated that expression of BgPGRP-SA and BgGNBP was down-regulated in B. glabrata at 6 h after exposure to three types of microbes. No significant changes in expression were observed in snails at 2 days post-exposure (dpe) to the trematodes Echinostoma paraensei or S. mansoni. However, up-regulation of BgPGRP-SA in M line snails at later time points of infection with E. paraensei (i.e., 12 and 17 dpe) was observed. Our study revealed that exposure to either microbes or trematodes did not alter the expression levels of BgPGRP-LAs, which were consistently low. This study provides new insights into the potential pathogen recognition capabilities of molluscs, indicates that further studies of the Toll/Imd pathways in this phylum are in order, and provides additional ways to judge the importance of this pathway in the evolution of internal defense across the animal phyla. PMID:17805526

[Effects of non-saccharomyces albicans metabolic products on the proliferation of human umbilical vein endothelial cell ECV304].

PubMed

Chen, Bin; Che, Tuanjie; Bai, Decheng; He, Xiangyi

2013-04-01

To evaluate the effects of non-Saccharomyces albicans metabolic products on the cell cycle distribution and proliferation of human umbilical vein endothelial cell ECV304 cells in vitro. The parallel dilution supernatant of Saccharomyces tropicalis, Saccharomyces krusei and Saccharomyces glabrata were prepared, and 1, 4, 16-fold(s) diluted concentration and control group were set up. The line of human umbilical vein endothelial cell ECV304 was cultured in vitro and treated by non-Saccharomyces albicans supernatant. The proliferous effect of ECV304 induced by non-Saccharomyces albicans supernatant after 24, 48, 72 h was detected by the methods of MTT, and the changes of cell density and cycle after 48 h were investigated by inverted microscope and flow cytometry. At the 24th hour, all of the higher concentration (1-fold) of non-Saccharomyces albicans supernatant and the 4-folds diluted Saccharomyces krusei could promote ECV304 proliferation(P < 0.05). After adding various non-Saccharomyces albicans supernatant at 48h and 72th hour, Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant significantly increased proliferation rate of ECV304, while Saccharomyces tropicalis supernatant group showed no significant change no matter which concentration was tested. At 48th hour after adding the non-Saccharomyces albicans supernatant, the ECV304 cells density treated by Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant were significantly higher under the inverted microscope. The G0/G1 population of ECV304 cells decreased while cell proliferation index (PI) increased after incubated with Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant for 48 hours (P < 0.05). Saccharomyces tropicalis group showed no significant change (P > 0.05). The metabolic products of Sacharoymces krusei and Saccharomyces glabrata could induce proliferation of ECV304 cell, which suggests non-Saccharomyces albicans should be undergone more

Schistosoma mansoni: resistant specific infection-induced gene expression in Biomphalaria glabrata identified by fluorescent-based differential display.

PubMed

Lockyer, Anne E; Noble, Leslie R; Rollinson, David; Jones, Catherine S

2004-01-01

The freshwater tropical snail Biomphalaria glabrata is an intermediate host for Schistosoma mansoni, the causative agent of human intestinal schistosomiasis, and strains differ in their susceptibility to parasite infection. Changes in gene expression in response to parasite infection have been simultaneously examined in a susceptible strain (NHM1742) and a resistant strain (NHM1981) using a newly developed fluorescent-based differential display method. Such RNA profiling techniques allow the examination of changes in gene expression in response to parasite infection, without requiring previous sequence knowledge, or selecting candidate genes that may be involved in the complex neuroendocrine or defence systems of the snail. Thus, novel genes may be identified. Ten transcripts were initially identified, present only in the profiles derived from snails of the resistant strain when exposed to infection. The differential expression of five of these genes, including HSP70 and several novel transcripts with one containing at least two globin-like domains, has been confirmed by semi-quantitative RT-PCR.

Impact of cold on the immune system of burying beetle, Nicrophorus vespilloides (Coleoptera: Silphidae).

PubMed

Urbański, Arkadiusz; Czarniewska, Elżbieta; Baraniak, Edward; Rosiński, Grzegorz

2017-06-01

Insect overwintering is one of the most astonishing phases of the insect life cycle. Despite vast amounts of knowledge available about the physiological mechanisms of this phenomenon, the impact of stress factors on insect immune system functioning during the winter is still unknown. The aim of this study is to analyze how low temperatures influence the immune system of the beetle Nicrophorus vespilloides. The results show that the beetle's immune system is differently modulated by cold induced in laboratory settings than that which occurs in natural conditions. Among beetles cultured in conditions similar to summer, low temperatures, did not influence the number of circulating haemocytes, phenoloxidase activity, haemocytes morphology, and percentage ratio of haemocyte types. In these beetles, differences were noted only in the ability of haemocytes to perform phagocytosis. Individuals acclimated in natural conditions in autumn had a higher level of humoral response and a different percentage ratio of haemocyte types. During the winter period, the number of haemocytes in the beetles decreased, but the percentage ratio of phagocytic haemocytes increased. Furthermore, we noted an increase of phenoloxidase activity. Our study also showed mitotic divisions of haemocytes in haemolymph collected from burying beetles after cold exposure and from burying beetles collected from natural conditions during autumn and winter. Differences in response to low temperatures in laboratory conditions and the natural environment suggest that the simultaneous presence of other stress factors during winter such as desiccation and starvation have a significant influence on the activity of burying beetle's immune system. © 2016 Institute of Zoology, Chinese Academy of Sciences.

A norepinephrine-responsive miRNA directly promotes CgHSP90AA1 expression in oyster haemocytes during desiccation.

PubMed

Chen, Hao; Xin, Lusheng; Song, Xiaorui; Wang, Lin; Wang, Weilin; Liu, Zhaoqun; Zhang, Huan; Wang, Lingling; Zhou, Zhi; Qiu, Limei; Song, Linsheng

2017-05-01

Oyster Crassostrea gigas is one model mollusc inhabiting in the intertidal zone and is frequently stressed by desiccation. The adaptation mechanism of oyster to environmental stress involves multiple levels, and miRNA is one of the most important regulators in post-transcriptional level. In the present study, an oyster norepinephrine-responsive miRNA cgi-miR-365 was proved to contribute to the host adaptation against desiccation by directly promoting the expression of CgHSP90AA1. Briefly, a significant increase of cgi-miR-365 was observed from the first day after aerial exposure and the up-regulation was vigorously repressed when oysters were injected with adrenoceptors antagonists. A total of 15 genes involved in biological regulation, metabolic process and response to stimulus were predicted to be modulated by cgi-miR-365. Among these genes, CgHSP90AA1 was up-regulated significantly during desiccation and could be down-regulated after simultaneous injection of adrenoceptors antagonists. The interaction between cgi-miR-365 and CgHSP90AA1 was subsequently verified in vitro, and a significant promotion of CgHSP90AA1 transcripts was observed after overexpressing cgi-miR-365 in either in vitro luciferase reporter assay or primarily cultured haemocytes. Meanwhile, CgHSP90AA1 transcripts decreased in vivo when cgi-miR-365 was repressed by its inhibitor during desiccation. Collectively, it was suggested that cgi-miR-365 could be induced by norepinephrine during desiccation and promote CgHSP90AA1 expression directly after binding to its 3'-UTR, which would provide new evidence in miRNA-mediated adaptation mechanism in oysters against intertidal stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of the Statocyst in the Freshwater Snail Biomphalaria Glabrata (Pulmonata, Basommatophora)

NASA Technical Reports Server (NTRS)

Gao, Wenyuan; Wiederhold, Michael; Hejl, Robert

1997-01-01

The development of the statocyst of the freshwater snail Biomphalaria glabrata has been examined from embryo to adult. Special emphasis was put on the growth of the statoconia in the statocysts. In the statocysts of embryonic snails (90-120 h after oviposition) there is not a single statolith but an average of 40-50 statoconia per statocyst. The number of statoconia increases to 385-400 when the snails reach a shell diameter of 4 mm and remains relatively constant thereafter, irrespective of shell size. Small statoconia are found in supporting cells, which suggests that the statoconia are produced within these cells. The average diameter of statoconia and the total mass of statoconia increase with increasing shell diameter. The average number of large statoconia (diameter greater than 7 micrometers) per statocyst continues to increase from 2 to 10 mm animals while the number of small ones (diameter less than 4 micrometers) initially rises and then decreases after 4 mm. These results demonstrate continuous growth of the statoconia in the cyst lumen of Biomphalaria. The single statoconia vibrate in a regular pattern in vivo, indicating beating of the statocyst cilia. The statoconia sink under the influence of gravity to load and stimulate receptor cells which are at the bottom. The length of cilia and the size of statocyst gradually increase as the animal grows. However, the increase in the volume of the statocyst is relatively small compared with the increase in body weight during normal development.

Green synthesis and characterization of gold and silver nanoparticles using Mussaenda glabrata leaf extract and their environmental applications to dye degradation.

PubMed

Francis, Sijo; Joseph, Siby; Koshy, Ebey P; Mathew, Beena

2017-07-01

Plant-derived nanomaterials opened a green approach in solving the current environment issues. Present study focused on rapid microwave-assisted synthesis and applications of gold and silver nanoparticles mediated by aqueous leaf extract of Mussaenda glabrata. The synthesized nanoparticles were characterized by UV-vis, FT-IR, powder XRD, energy-dispersive X-ray spectroscopy (EDX), transmission electron (TEM), and atomic force microscopic techniques (AFM). FCC crystal structure of both nanoparticles was confirmed by peaks corresponding to (111), (200), (220), and (311) planes in XRD spectra and bright circular spots in SAED pattern. IC 50 values shown by gold and silver nanoparticles (44.1 ± 0.82 and 57.92 ± 1.33 μg/mL) reflected their high free radical scavenging potential. The synthesized gold and silver nanoparticles revealed their potency to inhibit pathogenic microorganisms Bacillus pumilus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Aspergillus niger, and Penicillium chrysogenum. Anthropogenic pollutants rhodamine B and methyl orange were effectively degraded from aquatic environment and waste water sewages of dye industries using the prepared nanocatalysts. The catalytic capacities of the synthesized nanoparticles were also exploited in the reduction of 4-nitrophenol. Graphical abstract.

Transfection and heat-inducible expression of molluscan promoter-luciferase reporter gene constructs in the Biomphalaria glabrata embryonic snail cell line.

PubMed

Yoshino, T P; Wu, X J; Liu, H D

1998-09-01

Studies were initiated to begin developing a genetic transformation system for cells derived from the freshwater gastropod, Biomphalaria glabrata, an intermediate host of the human blood fluke Schistosoma mansoni. Using a 70-kD heat-shock protein (HSP70) cDNA probe obtained from the B. glabrata embryonic (Bge) cell line, we cloned from Bge cells a complete HSP70 gene including a 1-kb genomic DNA fragment in its 5'-flanking region containing sequences indicative of a HSP promoter. Identified in the 5'-half (416 nucleotides) of this genomic fragment were TATA and CAAT boxes, two putative transcription initiation sites, and a series of palindromic DNA repeats with shared homology to the heat-shock element consensus sequence (Bge HSP70(0.5k) promoter). The 3'-half of this upstream flanking region was comprised of a 508-base intron located immediately 5' of the ATG start codon. To determine the functionality of the putative snail promoter sequence, Bge HSP promoter/luciferase (Luc) reporter gene constructs were introduced into Bge cells by N-(1-(2,3-dioleoyloxy) propyl)-N,N,N-trimethylammonium methylsulfate (DOTAP)-mediated transfection methods, and assayed for Luc activity 48 hr following a 1.5-hr heat-shock treatment (40 degrees C). Compared with control vectors or the Bge HSP70(0.5k/1.0k) promoter constructs at 26 degrees C, a 10- to 300-fold increase in Luc expression was obtained only in the Bge HSP70 promoter/Luc-transfected cells following heat-shock. Results of transfection experiments demonstrate that the Bge HSP70(0.5k) DNA segment contains appropriate promoter sequences for driving temperature-inducible gene expression in the Bge snail cell line. This report represents the first isolation and functional characterization of an inducible promoter from a freshwater gastropod mollusc. Successful transient expression of a foreign reporter gene in Bge cells using a homologous, inducible promoter sequence now paves the way for development of methods for stable

Perennial peanut (Arachis glabrata Benth.) contains polyphenol oxidase (PPO) and PPO substrates that can reduce post-harvest proteolysis.

PubMed

Sullivan, Michael L; Foster, Jamie L

2013-08-15

Studies of perennial peanut (Arachis glabrata Benth.) suggest its hay and haylage have greater levels of rumen undegraded protein (RUP) than other legume forages such as alfalfa (Medicago sativa L.). Greater RUP can result in more efficient nitrogen utilization by ruminant animals with positive economic and environmental effects. We sought to determine whether, like red clover (Trifolium pretense L.), perennial peanut contains polyphenol oxidase (PPO) and PPO substrates that might be responsible for increased RUP. Perennial peanut extracts contain immunologically detectible PPO protein and high levels of PPO activity (>100 nkatal mg(-1) protein). Addition of caffeic acid (PPO substrate) to perennial peanut extracts depleted of endogenous substrates reduced proteolysis by 90%. Addition of phenolics prepared from perennial peanut leaves to extracts of either transgenic PPO-expressing or control (non-expressing) alfalfa showed peanut phenolics could reduce proteolysis >70% in a PPO-dependent manner. Two abundant likely PPO substrates are present in perennial peanut leaves including caftaric acid. Perennial peanut contains PPO and PPO substrates that together are capable of inhibiting post-harvest proteolysis, suggesting a possible mechanism for increased RUP in this forage. Research related to optimizing the PPO system in other forage crops will likely be applicable to perennial peanut. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Drosophila as a model to study the role of blood cells in inflammation, innate immunity and cancer

PubMed Central

Wang, Lihui; Kounatidis, Ilias; Ligoxygakis, Petros

2014-01-01

Drosophila has a primitive yet effective blood system with three types of haemocytes which function throughout different developmental stages and environmental stimuli. Haemocytes play essential roles in tissue modeling during embryogenesis and morphogenesis, and also in innate immunity. The open circulatory system of Drosophila makes haemocytes ideal signal mediators to cells and tissues in response to events such as infection and wounding. The application of recently developed and sophisticated genetic tools to the relatively simple genome of Drosophila has made the fly a popular system for modeling human tumorigensis and metastasis. Drosophila is now used for screening and investigation of genes implicated in human leukemia and also in modeling development of solid tumors. This second line of research offers promising opportunities to determine the seemingly conflicting roles of blood cells in tumor progression and invasion. This review provides an overview of the signaling pathways conserved in Drosophila during haematopoiesis, haemostasis, innate immunity, wound healing and inflammation. We also review the most recent progress in the use of Drosophila as a cancer research model with an emphasis on the roles haemocytes can play in various cancer models and in the links between inflammation and cancer. PMID:24409421

Drosophila as a model to study the role of blood cells in inflammation, innate immunity and cancer.

PubMed

Wang, Lihui; Kounatidis, Ilias; Ligoxygakis, Petros

2014-01-09

Drosophila has a primitive yet effective blood system with three types of haemocytes which function throughout different developmental stages and environmental stimuli. Haemocytes play essential roles in tissue modeling during embryogenesis and morphogenesis, and also in innate immunity. The open circulatory system of Drosophila makes haemocytes ideal signal mediators to cells and tissues in response to events such as infection and wounding. The application of recently developed and sophisticated genetic tools to the relatively simple genome of Drosophila has made the fly a popular system for modeling human tumorigensis and metastasis. Drosophila is now used for screening and investigation of genes implicated in human leukemia and also in modeling development of solid tumors. This second line of research offers promising opportunities to determine the seemingly conflicting roles of blood cells in tumor progression and invasion. This review provides an overview of the signaling pathways conserved in Drosophila during haematopoiesis, haemostasis, innate immunity, wound healing and inflammation. We also review the most recent progress in the use of Drosophila as a cancer research model with an emphasis on the roles haemocytes can play in various cancer models and in the links between inflammation and cancer.

Epigenetic modulation, stress and plasticity in susceptibility of the snail host, Biomphalaria glabrata, to Schistosoma mansoni infection.

PubMed

Knight, Matty; Ittiprasert, Wannaporn; Arican-Goktas, Halime D; Bridger, Joanna M

2016-06-01

Blood flukes are the causative agent of schistosomiasis - a major neglected tropical disease that remains endemic in numerous countries of the tropics and sub-tropics. During the past decade, a concerted effort has been made to control the spread of schistosomiasis, using a drug intervention program aimed at curtailing transmission. These efforts notwithstanding, schistosomiasis has re-emerged in southern Europe, raising concerns that global warming could contribute to the spread of this disease to higher latitude countries where transmission presently does not take place. Vaccines against schistosomiasis are not currently available and reducing transmission by drug intervention programs alone does not prevent reinfection in treated populations. These challenges have spurred awareness that new interventions to control schistosomiasis are needed, especially since the World Health Organization hopes to eradicate the disease by 2025. For one of the major species of human schistosomes, Schistosoma mansoni, the causative agent of hepatointestinal schistosomiasis in Africa and the Western Hemisphere, freshwater snails of the genus Biomphalaria serve as the obligate intermediate host of this parasite. To determine mechanisms that underlie parasitism by S. mansoni of Biomphalaria glabrata, which might be manipulated to block the development of intramolluscan larval stages of the parasite, we focused effort on the impact of schistosome infection on the epigenome of the snail. Results to date reveal a complex relationship, manifested by the ability of the schistosome to manipulate the snail genome, including the expression of specific genes. Notably, the parasite subverts the stress response of the host to ensure productive parasitism. Indeed, in isolates of B. glabrata native to central and South America, susceptible to infection with S. mansoni, the heat shock protein 70 (Bg-HSP70) gene of this snail is rapidly relocated in the nucleus and transcribed to express HSP70

[CaCO3 stimulates alpha-ketoglutarate accumulation during pyruvate fermentation by Torulopsis glabrata].

PubMed

Liu, Li-Ming; Li, Yin; Du, Guo-Cheng; Chen, Jian

2003-11-01

A large amount of alpha-ketoglutarate (alpha-KG) (6.8 g/L) was accumulated in flask culture when CaCO3 was used as a buffering agent in the production of pyruvate by multi-vitamin auxotrophic yeast Torulopsis glabrata CCTCC M202019. In a 5 L jar-fermentor, less alpha-KG (1.3 g/L) was produced when NaOH was used to adjust the pH, while more alpha-KG (11.5 g/L) detected when CaCO3 was used as the buffer. In the latter case, the molar carbon ratio of pyruvate to alpha-KG (C(PYR)/ CalphaKG) was similar to that obtained in flask culture, suggesting the accumulation of alpha-ketoglutarate was related to the addition of CaCO3. Furthermore, it was found that: (1) delaying the addition time of CaCO3 decreased the a-ketoglutarate formation but increased C(PYR)/ C(alphaKG); and (2) under vitamin limitation conditions increasing the concentration of CaCO3 led to an increased a-KG accumulation at the expenses of pyruvate. To study which ions in CaCO3 was responsible for the accumulation of alpha-KG, the effects of different pH buffers on the a-KG accumulation were studied. The level of alpha-KG was found to correlate with the levels of both Ca2+ and CO3(2-), with Ca2+ played a dominant role and CO3(2-) played a minor role. To find out which pathway was responsible for the accumulation of alpha-KG, the effects of biotin and thiamine on alpha-KG accumulation was investigated. The increase in biotin concentration led to an increase in alpha-KG accumulation and a decrease in C(PYR)/ C(alpha-KG), while the levels of alpha-KG and C(PYR)/C(alphaKG) were not affected by thiamine concentration. The activity of pyruvate carboxylase was increased as much as 40% when the medium was supplemented with Ca2+ . On the other hand, the activity of the pyruvate dehydrogenase complex was unaffected by the presence of Ca2+. To conclude, the higher level of a-KG was caused by higher activity of pyruvate carboxylase stimulated by Ca2+, with CO3(2-) served as the substrate of the reaction.

A novel membrane-integrated fermentation reactor system: application to pyruvic acid production in continuous culture by Torulopsis glabrata.

PubMed

Sawai, Hideki; Mimitsuka, Takashi; Minegishi, Shin-Ichi; Henmi, Masahiro; Yamada, Katsushige; Shimizu, Sakayu; Yonehara, Tetsu

2011-08-01

This paper describes the performance of a novel bio-reactor system, the membrane-integrated fermentation reactor (MFR), for efficient continuous fermentation. The MFR, equipped with an autoclavable polyvinylidene difluoride membrane, has normally been used for biological wastewater treatment. The productivity of the MFR system, applied to the continuous production of pyruvic acid by the yeast Torulopsis glabrata, was remarkably high. The volumetric productivity of pyruvic acid increased up to 4.2 g/l/h, about four times higher than that of batch fermentation. Moreover, the membrane was able to filter fermentation broth for more than 300 h without fouling even though the cell density of the fermentation broth reached 600 as OD(660). Transmembrane pressure, used as an indicator of membrane fouling, remained below 5 kPa throughout the continuous fermentation. These results clearly indicate that the MFR system is a simple and highly efficient system that is applicable to the fermentative production of a range of biochemicals.

Candida glabrata binds to glycosylated and lectinic receptors on the coronary endothelial luminal membrane and inhibits flow sense and cardiac responses to agonists.

PubMed

Torres-Tirado, David; Knabb, Maureen; Castaño, Irene; Patrón-Soberano, Araceli; De Las Peñas, Alejandro; Rubio, Rafael

2016-01-01

Candida glabrata (CG) is an opportunistic fungal pathogen that initiates infection by binding to host cells via specific lectin-like adhesin proteins. We have previously shown the importance of lectin-oligosaccharide binding in cardiac responses to flow and agonists. Because of the lectinic-oligosaccharide nature of CG binding, we tested the ability of CG to alter the agonist- and flow-induced changes in cardiac function in isolated perfused guinea pig hearts. Both transmission and scanning electron microscopy showed strong attachment of CG to the coronary endothelium, even after extensive washing. CG shifted the coronary flow vs. auricular-ventricular (AV) delay relationship upward, indicating that greater flow was required to achieve the same AV delay. This effect was completely reversed with mannose, partially reversed with galactose and N-acetylgalactosamine, but hyaluronan had no effect. Western blot analysis was used to determine binding of CG to isolated coronary endothelial luminal membrane (CELM) receptors, and the results indicate that flow-sensitive CELM receptors, ANG II type I, α-adrenergic 1A receptor, endothelin-2, and VCAM-1 bind to CG. In addition, CG inhibited agonist-induced effects of bradykinin, angiotensin, and phenylephrine on AV delay, coronary perfusion pressure, and left ventricular pressure. Mannose reversed the inhibitory effects of CG on the agonist responses. These results suggest that CG directly binds to flow-sensitive CELM receptors via lectinic-oligosaccharide interactions with mannose and disrupts the lectin-oligosaccharide binding necessary for flow-induced cardiac responses. Copyright © 2016 the American Physiological Society.

Overcoming the heterologous bias: an in vivo functional analysis of multidrug efflux transporter, CgCdr1p in matched pair clinical isolates of Candida glabrata.

PubMed

Puri, Nidhi; Manoharlal, Raman; Sharma, Monika; Sanglard, Dominique; Prasad, Rajendra

2011-01-07

We have taken advantage of the natural milieu of matched pair of azole sensitive (AS) and azole resistant (AR) clinical isolates of Candida glabrata for expressing its major ABC multidrug transporter, CgCdr1p for structure and functional analysis. This was accomplished by tagging a green fluorescent protein (GFP) downstream of ORF of CgCDR1 and integrating the resultant fusion protein at its native chromosomal locus in AS and AR backgrounds. The characterization confirmed that in comparison to AS isolate, CgCdr1p-GFP was over-expressed in AR isolates due to its hyperactive native promoter and the GFP tag did not affect its functionality in either construct. We observed that in addition to Rhodamine 6 G (R6G) and Fluconazole (FLC), a recently identified fluorescent substrate of multidrug transporters Nile Red (NR) could also be expelled by CgCdr1p. Competition assays with these substrates revealed the presence of overlapping multiple drug binding sites in CgCdr1p. Point mutations employing site directed mutagenesis confirmed that the role played by unique amino acid residues critical to ATP catalysis and localization of ABC drug transporter proteins are well conserved in C. glabrata as in other yeasts. This study demonstrates a first in vivo novel system where over-expression of GFP tagged MDR transporter protein can be driven by its own hyperactive promoter of AR isolates. Taken together, this in vivo system can be exploited for the structure and functional analysis of CgCdr1p and similar proteins wherein the artefactual concerns encountered in using heterologous systems are totally excluded. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of traditional medical herbs "minor bupleurum decoction" on the non-specific immune responses of white shrimp (Litopenaeus vannamei).

PubMed

Wu, Yu-Sheng; Lee, Meng-Chou; Huang, Cheng-Ting; Kung, Tzu-Chi; Huang, Chih-Yang; Nan, Fan-Hua

2017-05-01

This study is investigating the effect of minor bupleurum decoction (Xiao-Chai-Hu decoction) on the non-specific immune response of white shrimp (Litopenaeus vannamei). To determine prophenoloxidase activity (proPO), reactive oxygen species production (ROS), superoxide anion production (O 2 - ), nitric oxide production (NO), phagocytic rate (PR), phagocytic index (PI), superoxide dismutase activity (SOD), total haemocyte count (THC) and differential haemocyte count (DHC). In this experiment, treating with different dosages (0, 0.25, 0.5 and, 1%) of minor bupleurum decoction to detect immune parameters on day 0, 1, 2, 4, 7, 14, 21 and 28. Result is shown that 0.25% treatment significantly enhanced the superoxide dismutase (SOD) activity and, 0.25 and 1% treatment significantly increased the ROS production, nitric oxide (NO) production and phagocytic rate (PR) moreover, 0.5 and 1% treatment induced the proPO activity and superoxide anion (O 2 - ) production. Evidence exactly indicated that minor bupleurum decoction is able to enhance the non-specific immunity responses of white shrimp via in vivo examination. Copyright © 2017 Elsevier Ltd. All rights reserved.

Drosophila haematopoiesis.

PubMed

Crozatier, Michèle; Meister, Marie

2007-05-01

Like in vertebrates, Drosophila haematopoiesis occurs in two waves. It gives rise to three types of haemocytes: plasmatocytes (phagocytosis), crystal cells (melanization) and lamellocytes (encapsulation of parasites). A first population of haemocytes, specified during embryogenesis, gives rise to an invariant number of plasmatocytes and crystal cells. A second population of haemocytes is specified during larval development in a specialized haematopoietic organ, the lymph gland. All three types of haemocytes can be specified in this organ, but lamellocytes only differentiate in response to parasitism. Thus, larval in contrast to embryonic haematopoiesis can be modulated by physiological constraints. Molecular cascades controlling embryonic haematopoiesis are relatively well established and require transactivators such as GATA, FOG and Runx factors, which are also co-opted in mammalian haematopoiesis. Mechanisms involved during larval haematopoiesis are less well understood although a number of chromatin remodelling factors and signalling pathways (JAK/STAT, Toll, Hedgehog, Notch) are required. In healthy larvae a pool of progenitors is maintained within the lymph gland, under the control of a signalling centre which expresses Collier, Serrate, Antennapedia and Hedgehog, and controls haemocyte homeostasis. Its key role in haemocyte homeostasis is reminiscent of interactions described in vertebrates between haematopoietic stem cells and their microenvironment (niche).

Variation of parasite load and immune parameters in two species of New Zealand shore crabs.

PubMed

Dittmer, Jessica; Koehler, Anson V; Richard, Freddie-Jeanne; Poulin, Robert; Sicard, Mathieu

2011-09-01

While parasites are likely to encounter several potential intermediate hosts in natural communities, a parasite's actual range of compatible hosts is limited by numerous biological factors ranging from behaviour to immunology. In crustaceans, two major components of immunity are haemocytes and the prophenoloxidase system involved in the melanisation of foreign particles. Here, we analysed metazoan parasite prevalence and loads in the two sympatric crab species Hemigrapsus crenulatus and Macrophthalmus hirtipes at two sites. In parallel, we analysed the variation in haemocyte concentration and amount of circulating phenoloxidase (PO) in the haemolymph of the same individuals in an attempt to (a) explain differences in parasite prevalence and loads in the two species at two sites and (b) assess the impact of parasites on these immune parameters. M. hirtipes harboured more parasites but also exhibited higher haemocyte concentrations than H. crenulatus independent of the study site. Thus, higher investment in haemocyte production for M. hirtipes does not seem to result in higher resistance to parasites. Analyses of variation in immune parameters for the two crab species between the two sites that differed in parasite prevalence showed common trends. (a) In general, haemocyte concentrations were higher at the site experiencing higher parasitic pressure while circulating PO activity was lower and (b) haemocyte concentrations were influenced by microphallid trematode metacercariae in individuals from the site with higher parasitic pressure. We suggest that the higher haemocyte concentrations observed in both crab species exposed to higher parasitic pressure may represent an adaptive response to the impact of parasites on this immune parameter.

Seasonal and gender-related differences in morphometric features and cellular and biochemical parameters of Carcinus aestuarii from the Lagoon of Venice.

PubMed

Matozzo, Valerio; Boscolo, Alice; Marin, Maria Gabriella

2013-08-01

In this study, the seasonal variations in the morphometric features and in the cellular and biochemical parameters of the haemolymph were investigated in both male and female crabs (Carcinus aestuarii). Crabs were seasonally (November 2010-August 2011) collected from the Lagoon of Venice, and the moult stage, weight, width and length of the carapace, and width and length of the bigger chela were evaluated. In addition, the total haemocyte count (THC), haemocyte diameter and volume, haemolymph glucose and total protein levels, and haemolymph phenoloxidase (PO) and N-acetyl-β-glucosaminidase (NAG) activities were measured. The results demonstrated that the collected crabs were all in the intermoult stage and that the males were bigger than the females. A two-way ANOVA revealed a significant effect of season on the THC and the haemocyte volume and a significant influence of gender on the haemocyte diameter. Season and gender significantly affected the haemolymph glucose concentration, whereas haemolymph protein levels were dependent only on the season. In addition, both season and gender significantly influenced the PO and NAG activities in the haemolymph. Overall, the results demonstrated that crab morphometric features as well as haemolymph cellular and biochemical parameters varied markedly as a function of both season and gender. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synergistic mutual potentiation of antifungal activity of Zuccagnia punctata Cav. and Larrea nitida Cav. extracts in clinical isolates of Candida albicans and Candida glabrata.

PubMed

Butassi, Estefanía; Svetaz, Laura A; Ivancovich, Juan J; Feresin, Gabriela E; Tapia, Alejandro; Zacchino, Susana A

2015-06-01

Zuccagnia punctata Cav. (Fabaceae) and Larrea nitida Cav. (Zygophyllaceae) are indistinctly or jointly used in traditional medicine for the treatment of fungal-related infections. Although their dichloromethane (DCM) extract have demonstrated moderate antifungal activities when tested on their own, antifungal properties of combinations of both plants have not been assessed previously. The aim of this study was to establish with statistical rigor whether Z. punctata (ZpE) and L. nitida DCM extract (LnE) interact synergistically against the clinically important fungi Candida albicans and Candida glabrata and to characterize the most synergistic combinations. For synergism assessment, the statistical-based Boik's design was applied. Eight ZpE-LnE fixed-ratio mixtures were prepared from four different months of 1 year and tested against Candida strains. Lϕ (Loewe index) of each mixture at different fractions affected (ϕ) allowed for the finding of the most synergistic combinations, which were characterized by HPLC fingerprint and by the quantitation of the selected marker compounds. Lϕ and confidence intervals were determined in vitro with the MixLow method, once the estimated parameters from the dose-response curves of independent extracts and mixtures, were obtained. Markers (four flavonoids for ZpE and three lignans for LnE) were quantified in each extract and their combinations, with a valid HPLC-UV method. The 3D-HPLC profiles of the most synergistic mixtures were obtained by HPLC-DAD. Three over four IC50ZpE/IC50LnE fixed-ratio mixtures displayed synergistic interactions at effect levels ϕ > 0.5 against C. albicans. The dosis of the most synergistic (Lϕ = 0.62) mixture was 65.96 µg/ml (ZpE = 28%; LnE = 72%) containing 8 and 36% of flavonoids and lignans respectively. On the other hand, one over four IC50ZpE/IC50LnE mixtures displays synergistic interactions at ϕ > 0.5 against C. glabrata. The dosis of the most synergistic (Lϕ = 0.67) mixture was 168

A Shift from Cellular to Humoral Responses Contributes to Innate Immune Memory in the Vector Snail Biomphalaria glabrata

PubMed Central

Pinaud, Silvain; Portela, Julien; Duval, David; Nowacki, Fanny C.; Olive, Marie-Aude; Allienne, Jean-François; Galinier, Richard; Dheilly, Nolwenn M.; Kieffer-Jaquinod, Sylvie; Mitta, Guillaume; Théron, André; Gourbal, Benjamin

2016-01-01

Discoveries made over the past ten years have provided evidence that invertebrate antiparasitic responses may be primed in a sustainable manner, leading to the failure of a secondary encounter with the same pathogen. This phenomenon called “immune priming” or "innate immune memory" was mainly phenomenological. The demonstration of this process remains to be obtained and the underlying mechanisms remain to be discovered and exhaustively tested with rigorous functional and molecular methods, to eliminate all alternative explanations. In order to achieve this ambitious aim, the present study focuses on the Lophotrochozoan snail, Biomphalaria glabrata, in which innate immune memory was recently reported. We provide herein the first evidence that a shift from a cellular immune response (encapsulation) to a humoral immune response (biomphalysin) occurs during the development of innate memory. The molecular characterisation of this process in Biomphalaria/Schistosoma system was undertaken to reconcile mechanisms with phenomena, opening the way to a better comprehension of innate immune memory in invertebrates. This prompted us to revisit the artificial dichotomy between innate and memory immunity in invertebrate systems. PMID:26735307

Analysis of the acute response of Galleria mellonella larvae to potassium nitrate.

PubMed

Maguire, Ronan; Kunc, Martin; Hyrsl, Pavel; Kavanagh, Kevin

2017-05-01

Potassium nitrate (E252) is widely used as a food preservative and has applications in the treatment of high blood pressure however high doses are carcinogenic. Larvae of Galleria mellonella were administered potassium nitrate to establish whether the acute effects in larvae correlated with those evident in mammals. Intra-haemocoel injection of potassium nitrate resulted in a significant increase in the density of circulating haemocytes and a small change in the relative proportions of haemocytes but haemocytes showed a reduced fungicidal ability. Potassium nitrate administration resulted in increased superoxide dismutase activity and in the abundance of a range of proteins associated with mitochondrial function (e.g. mitochondrial aldehyde dehydrogenase, putative mitochondrial Mn superoxide dismutase), metabolism (e.g. triosephosphate isomerase, glyceraldehyde 3 phosphate dehydrogenase) and nitrate metabolism (e.g. aliphatic nitrilase, glutathione S-transferase). A strong correlation exists between the toxicity of a range of food preservatives when tested in G. mellonella larvae and rats. In this work a correlation between the effect of potassium nitrate in larvae and mammals is shown and opens the way to the utilization of insects for studying the in vivo acute and chronic toxicity of xenobiotics. Copyright © 2017 Elsevier Inc. All rights reserved.

The Structure of the Statocyst of the Freshwater Snail Biomphalaria Glabrata (Pulmonata, Basommatophora)

NASA Technical Reports Server (NTRS)

Gao, Wenyuan; Wiederhold, Michael L.

1997-01-01

The structure of the statocyst of the freshwater snail Biomphalaria glabrata has been examined by light and electron microscopy. The two statocysts are located on the dorsal-lateral side of the left and right pedal ganglion. The statocysts are spherical, fluid-filled capsules with a diameter of approximately 60 microns for young and 110 microns for adult snails. The wall of the cyst is composed of large receptor cells and many smaller supporting cells. The receptor cells bear cilia which are evenly distributed on the apical surface. The cilia have the typical 9+2 internal tubule configuration. Striate rootlets originate from the base of the basal body and run downward into the cytoplasm. Side-roots arise from one side of the basal body and a basal foot from the other. For each receptor cell, the basal foot always points to the periphery of the surface, indicating that the receptor cell is non-polarized. The receptor cells contain cytoplasmic organelles such as mitochondria, ribosomes, rough and smooth endoplasmic reticulum, compact Golgi bodies and multivesicular bodies. Supporting cells bearing microvilli are interposed between the receptor cells. The junction complex between the supporting cells and the receptor cells is composed of adherens and septate junctions, while between supporting cells only the adherens junctions are present. The static nerve arises from the lateral side of the cyst and contains axons in which parallel neurotubules and mitochondria are found. The axons arise directly from the base of the receptor cells without synapse. In the cyst lumen there are unattached statoconia. The statoconia have a plate-like or concentric membranous ring structure. Based on the morphology, the function of the statocyst in Biomphalaria is discussed.

Challenging the Metallothionein (MT) Gene of Biomphalaria glabrata: Unexpected Response Patterns Due to Cadmium Exposure and Temperature Stress.

PubMed

Niederwanger, Michael; Dvorak, Martin; Schnegg, Raimund; Pedrini-Martha, Veronika; Bacher, Katharina; Bidoli, Massimo; Dallinger, Reinhard

2017-08-11

Metallothioneins (MTs) are low-molecular-mass, cysteine-rich, metal binding proteins. In most animal species, they are involved in metal homeostasis and detoxification, and provide protection from oxidative stress. Gastropod MTs are highly diversified, exhibiting unique features and adaptations like metal specificity and multiplications of their metal binding domains. Here, we show that the MT gene of Biomphalaria glabrata , one of the largest MT genes identified so far, is composed in a unique way. The encoding for an MT protein has a three-domain structure and a C-terminal, Cys-rich extension. Using a bioinformatic approach involving structural and in silico analysis of putative transcription factor binding sites (TFBs), we found that this MT gene consists of five exons and four introns. It exhibits a regulatory promoter region containing three metal-responsive elements (MREs) and several TFBs with putative involvement in environmental stress response, and regulation of gene expression. Quantitative real-time polymerase chain reaction (qRT-PCR) data indicate that the MT gene is not inducible by cadmium (Cd) nor by temperature challenges (heat and cold), despite significant Cd uptake within the midgut gland and the high Cd tolerance of metal-exposed snails.

Challenging the Metallothionein (MT) Gene of Biomphalaria glabrata: Unexpected Response Patterns Due to Cadmium Exposure and Temperature Stress

PubMed Central

Dvorak, Martin; Schnegg, Raimund; Pedrini-Martha, Veronika; Bacher, Katharina; Bidoli, Massimo; Dallinger, Reinhard

2017-01-01

Metallothioneins (MTs) are low-molecular-mass, cysteine-rich, metal binding proteins. In most animal species, they are involved in metal homeostasis and detoxification, and provide protection from oxidative stress. Gastropod MTs are highly diversified, exhibiting unique features and adaptations like metal specificity and multiplications of their metal binding domains. Here, we show that the MT gene of Biomphalaria glabrata, one of the largest MT genes identified so far, is composed in a unique way. The encoding for an MT protein has a three-domain structure and a C-terminal, Cys-rich extension. Using a bioinformatic approach involving structural and in silico analysis of putative transcription factor binding sites (TFBs), we found that this MT gene consists of five exons and four introns. It exhibits a regulatory promoter region containing three metal-responsive elements (MREs) and several TFBs with putative involvement in environmental stress response, and regulation of gene expression. Quantitative real-time polymerase chain reaction (qRT-PCR) data indicate that the MT gene is not inducible by cadmium (Cd) nor by temperature challenges (heat and cold), despite significant Cd uptake within the midgut gland and the high Cd tolerance of metal-exposed snails. PMID:28800079

Methodology for the Absolute Configuration Determination of Epoxythymols Using the Constituents of Ageratina glabrata.

PubMed

Arreaga-González, Héctor M; Pardo-Novoa, Julio C; Del Río, Rosa E; Rodríguez-García, Gabriela; Torres-Valencia, J Martín; Manríquez-Torres, J Jesús; Cerda-García-Rojas, Carlos M; Joseph-Nathan, Pedro; Gómez-Hurtado, Mario A

2018-01-26

A methodology to determine the enantiomeric excess and the absolute configuration (AC) of natural epoxythymols was developed and tested using five constituents of Ageratina glabrata. The methodology is based on enantiomeric purity determination employing 1,1'-bi-2-naphthol (BINOL) as a chiral solvating agent combined with vibrational circular dichroism (VCD) measurements and calculations. The conformational searching included an extensive Monte Carlo protocol that considered the rotational barriers to cover the whole conformational spaces. (+)-(8S)-10-Benzoyloxy-6-hydroxy-8,9-epoxythymol isobutyrate (1), (+)-(8S)-10-acetoxy-6-methoxy-8,9-epoxythymol isobutyrate (4), and (+)-(8S)-10-benzoyloxy-6-methoxy-8,9-epoxythymol isobutyrate (5) were isolated as enantiomerically pure constituents, while 10-isobutyryloxy-8,9-epoxythymol isobutyrate (2) was obtained as a 75:25 (8S)/(8R) scalemic mixture. In the case of 10-benzoyloxy-8,9-epoxythymol isobutyrate (3), the BINOL methodology revealed a 56:44 scalemic mixture and the VCD measurement was beyond the limit of sensitivity since the enantiomeric excess is only 12%. The racemization process of epoxythymol derivatives was studied using compound 1 and allowed the clarification of some stereochemical aspects of epoxythymol derivatives since their ACs have been scarcely analyzed and a particular behavior in their specific rotations was detected. In more than 30 oxygenated thymol derivatives, including some epoxythymols, the reported specific rotation values fluctuate from -1.6 to +1.4 passing through zero, suggesting the presence of scalemic and close to racemic mixtures, since enantiomerically pure natural constituents showed positive or negative specific rotations greater than 10 units.

Interactions between environmental variables determine immunity in the Indian meal moth Plodia interpunctella.

PubMed

Triggs, Alison; Knell, Robert J

2012-03-01

1. Animals raised in good environmental conditions are expected to have more resources to invest in immunity than those raised in poor conditions. Variation in immune activity and parasite resistance in response to changes in environmental temperature, population density and food quality have been shown in many invertebrate species. 2. Almost all studies to date have examined the effects of individual variables in isolation. The aim of this study was to address whether environmental factors interact to produce synergistic effects on phenoloxidase (PO) activity and haemocyte count, both indicators of immune system activity. Temperature, food quality and density were varied in a fully factorial design for a total of eight treatment combinations. 3. Strong interactions between the three environmental variables led to the magnitude and in some cases the direction of the effect of most variables changing as the other environmental factors were altered. Overall, food quality had the most important and consistent influence, larvae raised on a good-quality diet having substantially higher PO activity in every case and substantially higher haemocyte counts in all treatments except unheated/low density. 4. When food quality was good, the larvae showed 'density-dependent prophylaxis': raising their investment in immunity when population density is high. When food quality was poor and the temperature low, however, those larvae raised at high densities invested less in immunity. 5. Increased temperature is often thought to lead to increased immune reactivity in ectotherms, but we found that the effect of temperature was strongly dependent on the values of other environmental variables. PO activity increased with temperature when larvae were raised on good food or when density was high, but when food was poor and density low, a higher temperature led to reduced PO activity. A higher temperature led to higher haemocyte counts when density was high and food quality was poor, but

Production a monoclonal antibody specific to granulocytes of swimming crab (Portunus trituberculatus) and its cross reactivity with other crustaceans.

PubMed

Cheng, Shun-Feng; Wu, Xiao-Chun; Zhang, Min

2016-10-01

In this study, a monoclonal antibody (mAb) 3F4 specific to granulocytes of swimming crab, Portunus trituberculatus, was obtained by immunizing mice with whole haemocytes. mAb 3F4 showed strong immunofluorescent reaction with granulocytes, but no reaction with hyalinocytes. The positive cell percentage of granulocytes was 86.3% detected by Flow cytometry (FCM). A special antigen with molecular weight of about 26kDa was further recognized by mAb 3F4 in haemocytes of P. trituberculatus. mAb 3F4 also showed strong cross-reactivity with haemocytes of Eriocheir sinensis and Petalomera japonica, but no reaction with other crustaceans tested. In E. sinensis, the positive cell percentage was 73.4% for granulocytes and 59.8% for hyalinocytes; while in P. japonica, the positive cell percentage was 81.2% for granulocytes and 7.1% for hyalinocytes. There was also a special antigen with molecular weight of about 31kDa identified by mAb 3F4 in haemocytes of E.sinensis, but no corresponding protein band in P. japonica haemocytes. These results demonstrated that mAb 3F4 can be used as a marker for granulocytes of crabs. Copyright © 2016 Elsevier B.V. All rights reserved.

Bioactivity Evaluation of Plant Extracts Used in Indigenous Medicine against the Snail, Biomphalaria glabrata, and the Larvae of Aedes aegypti.

PubMed

Dos Santos, Edilson Alves; de Carvalho, Cenira M; Costa, Ana L S; Conceição, Adilva S; Moura, Flávia de B Prado; Santana, Antônio Euzébio Goulart

2012-01-01

This investigation examined the molluscicidal and larvicidal activity of eight plants that are used in the traditional medicine of the Pankararé indigenous people in the Raso da Catarina region, Bahia state, Brazil. The tested plants were chosen based on the results of previous studies. Only those plants that were used either as insect repellents or to treat intestinal parasitic infections were included in the study. Crude extracts (CEs) of these plants were tested for their larvicidal activity (against Aedes aegypti larvae in the fourth instar) and molluscicidal activity (against the snail Biomphalaria glabrata). The plant species Scoparia dulcis and Helicteres velutina exhibited the best larvicidal activities (LC(50) 83.426 mg/L and LC(50) 138.896 mg/L, resp.), and Poincianella pyramidalis, Chenopodium ambrosoides, and Mimosa tenuiflora presented the best molluscicidal activities (LC(50) 0.94 mg/L, LC(50) 13.51 mg/L, and LC(50) 20.22 mg/L, resp.). As we used crude extracts as the tested materials, further study is warranted to isolate and purify the most active compounds.

Bioactivity Evaluation of Plant Extracts Used in Indigenous Medicine against the Snail, Biomphalaria glabrata, and the Larvae of Aedes aegypti

PubMed Central

dos Santos, Edilson Alves; de Carvalho, Cenira M.; Costa, Ana L. S.; Conceição, Adilva S.; Moura, Flávia de B. Prado; Santana, Antônio Euzébio Goulart

2012-01-01

This investigation examined the molluscicidal and larvicidal activity of eight plants that are used in the traditional medicine of the Pankararé indigenous people in the Raso da Catarina region, Bahia state, Brazil. The tested plants were chosen based on the results of previous studies. Only those plants that were used either as insect repellents or to treat intestinal parasitic infections were included in the study. Crude extracts (CEs) of these plants were tested for their larvicidal activity (against Aedes aegypti larvae in the fourth instar) and molluscicidal activity (against the snail Biomphalaria glabrata). The plant species Scoparia dulcis and Helicteres velutina exhibited the best larvicidal activities (LC50 83.426 mg/L and LC50 138.896 mg/L, resp.), and Poincianella pyramidalis, Chenopodium ambrosoides, and Mimosa tenuiflora presented the best molluscicidal activities (LC50 0.94 mg/L, LC50 13.51 mg/L, and LC50 20.22 mg/L, resp.). As we used crude extracts as the tested materials, further study is warranted to isolate and purify the most active compounds. PMID:22194773

Atomic structure of the nuclear pore complex targeting domain of a Nup116 homologue from the yeast, Candida glabrata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sampathkumar, Parthasarathy; Kim, Seung Joong; Manglicmot, Danalyn

2012-10-23

The nuclear pore complex (NPC), embedded in the nuclear envelope, is a large, dynamic molecular assembly that facilitates exchange of macromolecules between the nucleus and the cytoplasm. The yeast NPC is an eightfold symmetric annular structure composed of {approx}456 polypeptide chains contributed by {approx}30 distinct proteins termed nucleoporins. Nup116, identified only in fungi, plays a central role in both protein import and mRNA export through the NPC. Nup116 is a modular protein with N-terminal 'FG' repeats containing a Gle2p-binding sequence motif and a NPC targeting domain at its C-terminus. We report the crystal structure of the NPC targeting domain ofmore » Candida glabrata Nup116, consisting of residues 882-1034 [CgNup116(882-1034)], at 1.94 {angstrom} resolution. The X-ray structure of CgNup116(882-1034) is consistent with the molecular envelope determined in solution by small-angle X-ray scattering. Structural similarities of CgNup116(882-1034) with homologous domains from Saccharomyces cerevisiae Nup116, S. cerevisiae Nup145N, and human Nup98 are discussed.« less

Roles of dopamine receptors in mediating acute modulation of immunological responses in Macrobrachium rosenbergii.

PubMed

Chang, Zhong-Wen; Ke, Zhi-Han; Chang, Chin-Chyuan

2016-02-01

Dopamine (DA) was found to influence the immunological responses and resistance to pathogen infection in invertebrates. To clarify the possible modulation of DA through dopamine receptors (DAR) against acute environmental stress, the levels of DA, glucose and lactate in the haemolymph of Macrobrachium rosenbergii under hypo- and hyperthermal stresses were measured. The changes in immune parameters such as total haemocyte count (THC), differential haemocyte count (DHC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and phagocytic activity (PA) were evaluated in prawns which received DAR antagonists (SCH23390, SCH, D1 antagonist; domperidone, DOM, D2 antagonist; chlorpromazine, CH, D1+2 antagonist) followed by hypo- (15 °C) and hyperthermal (34 °C) stresses. In addition, pharmacological analysis of the effect DA modulation was studied in haemocytes incubated with DA and DAR antagonists. The results revealed a significant increase in haemolymph DA accompanied with upregulated levels of glucose and lactate in prawns exposed to both hypo- and hyperthermal stresses in 2 h. In addition, a significant decrease in RBs per haemocyte was noted in prawns which received DAR antagonists when they exposed to hyperthermal stress for 30 min. In in vitro test, antagonism on RBs, SOD and GPx activity of haemocytes were further evidenced through D1, D1, D1+D2 DARs, respectively, in the meantime, no significant difference in PO activity and PA was observed among the treatment groups. These results suggest that the upregulation of DA, glucose and lactate in haemolymph might be the response to acute thermal stress for the demand of energy, and the DAR occupied by its antagonistic action impart no effect on immunological responses except RBs in vivo even though the modulation mediated through D1 DAR was further evidenced in RBs, SOD and GPx activities in vitro. It is therefore concluded that thermal

Purification, Reconstitution, and Inhibition of Cytochrome P-450 Sterol Δ22-Desaturase from the Pathogenic Fungus Candida glabrata

PubMed Central

Lamb, David C.; Maspahy, Segula; Kelly, Diane E.; Manning, Nigel J.; Geber, Antonia; Bennett, John E.; Kelly, Steven L.

1999-01-01

Sterol Δ22-desaturase has been purified from a strain of Candida glabrata with a disruption in the gene encoding sterol 14α-demethylase (cytochrome P-45051; CYP51). The purified cytochrome P-450 exhibited sterol Δ22-desaturase activity in a reconstituted system with NADPH–cytochrome P-450 reductase in dilaurylphosphatidylcholine, with the enzyme kinetic studies revealing a Km for ergosta-5,7-dienol of 12.5 μM and a Vmax of 0.59 nmol of this substrate metabolized/min/nmol of P-450. This enzyme is encoded by CYP61 (ERG5) in Saccharomyces cerevisiae, and homologues have been shown in the Candida albicans and Schizosaccharomyces pombe genome projects. Ketoconazole, itraconazole, and fluconazole formed low-spin complexes with the ferric cytochrome and exhibited type II spectra, which are indicative of an interaction between the azole moiety and the cytochrome heme. The azole antifungal compounds inhibited reconstituted sterol Δ22-desaturase activity by binding to the cytochrome with a one-to-one stoichiometry, with total inhibition of enzyme activity occurring when equimolar amounts of azole and cytochrome P-450 were added. These results reveal the potential for sterol Δ22-desaturase to be an antifungal target and to contribute to the binding of drugs within the fungal cell. PMID:10390230

Introducing fluorescence resonance energy transfer-based biosensors for the analysis of cAMP-PKA signalling in the fungal pathogen Candida glabrata.

PubMed

Demuyser, Liesbeth; Van Genechten, Wouter; Mizuno, Hideaki; Colombo, Sonia; Van Dijck, Patrick

2018-05-29

The cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway is central to signal transduction in many organisms. In pathogenic fungi such as Candida albicans, this signalling cascade has proven to be involved in several processes, such as virulence, indicating its potential importance in antifungal drug discovery. Candida glabrata is an upcoming pathogen of the same species, yet information regarding the role of cAMP-PKA signalling in virulence is largely lacking. To enable efficient monitoring of cAMP-PKA activity in this pathogen, we here present the usage of two FRET-based biosensors. Both variations in the activity of PKA and the quantity of cAMP can be detected in a time-resolved manner, as we exemplify by glucose-induced activation of the pathway. We also present information on how to adequately process and analyse the data in a mathematically correct and physiologically relevant manner. These sensors will be of great benefit for scientists interested in linking the cAMP-PKA signalling cascade to downstream processes, such as virulence, possibly in a host environment. © 2018 John Wiley & Sons Ltd.

Cloning and characterization of tyrosine hydroxylase (TH) from the pacific white leg shrimp Litopenaeus vannamei, and its expression following pathogen challenge and hypothermal stress.

PubMed

Mapanao, Ratchaneegorn; Cheng, Winton

2016-09-01

Tyrosine hydroxylase (TH) belongs to the biopterin-dependent aromatic amino acid hydroxylase enzyme family, and it represents the first and rate-limiting step in the synthesis of catecholamines that are required for physiological and immune process in invertebrates and vertebrates. Cloned Litopenaeus vannamei TH (LvTH), containing a short alpha helix domain, a catalytic core, a regulatory domain, a phosphorylation site and two potential N-linked glycosylation sites as presented in vertebrate and insect THs without acidic region and signal peptide cleavage sites at the amino-terminal, exhibited a similarity of 60.0-61.2% and 45.0-47.0% to that of invertebrate and vertebrate THs, respectively. Further, LvTH expression was abundant in gill and haemocytes determined by quantitative real-time PCR. L. vannamei challenged with Vibrio alginolyticus at 10(5) cfu shrimp(-1) revealed significant increase of LvTH mRNA expression in haemocytes within 30-120 min and in brain within 15-30 min followed with recuperation. In addition, shrimps exposed to hypothermal stress at 18 °C significantly increased LvTH expression in haemocytes and brain within 30-60 and 15-60 min, respectively. The TH activity and haemolymph glucose level (haemocytes-free) significantly increased in pathogen challenged shrimp at 120 min and 60 min, and in hypothermal stressed shrimp at 30-60 and 30 min, respectively. These results affirm that stress response initiates in the brain while haemocytes display later response. Further, the significant elevation of TH activity in haemolymph is likely to confer by TH that released from haemocytes. In conclusion, the cloned LvTH in our current study is a neural TH enzyme appears to be involved in the physiological and immune responses of whiteleg shrimp, L. vannamei suffering stressful stimulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The cytochemical and ultrastructural characteristics of phagocytes in the Pacific oyster Crassostrea gigas.

PubMed

Jiang, Shuai; Jia, Zhihao; Xin, Lusheng; Sun, Ying; Zhang, Ran; Wang, Weilin; Wang, Lingling; Song, Linsheng

2016-08-01

Phagocytes have been proved to play vital roles in the innate immune response. However, the cellular characteristics of phagocytes in invertebrates, especially in molluscs, remain largely unknown. In the present study, fluorescence activated cell sorting (FACS) was employed to sort the phagocytes from the non-phagocytic haemocytes of the Pacific oyster Crassostrea gigas. The cytochemical staining analysis revealed that phagocytes were positive staining for α-naphthyl acetate esterase and myeloperoxidase, while negative staining for toluidine blue and periodic acid-Schiff. The non-phagocytic haemocytes exhibited positive staining for periodic acid-Schiff, weak positive staining for toluidine blue, but negative staining for α-naphthyl acetate esterase and myeloperoxidase. In addition, phagocytes exhibited ultrastructural cellular features similar to those of macrophages, with large cell diameter, rough cell membrane and extended pseudopodia revealed by the scanning electron microscopy, while the non-phagocytic haemocytes exhibited small cell diameter, smooth cell surface and round spherical shape. Transmission electron microscopy further demonstrated that phagocytes were abundant of cytoplasmic bodies and mitochondria, while non-phagocytic haemocytes were characterized as the comparatively large cell nucleus with contorted and condensed heterochromatin adherent to the nuclear envelope. Moreover, compared with non-phagocytic haemocytes, phagocytes exhibited significantly higher levels of intracellular cytokines, including tumor necrosis factor, interferon-like protein and interleukin-17, and significantly higher abundance of lysosome and reactive oxygen species, which were of great importance to the activation of immune response and pathogen clearance. Taken together, these findings revealed the different cytochemical and ultrastructural features between phagocytes and non-phagocytic haemocytes in C. gigas, which would provide an important clue to investigate the

The simple neuroendocrine-immune regulatory network in oyster Crassostrea gigas mediates complex functions.

PubMed

Liu, Zhaoqun; Wang, Lingling; Zhou, Zhi; Sun, Ying; Wang, Mengqiang; Wang, Hao; Hou, Zhanhui; Gao, Dahai; Gao, Qiang; Song, Linsheng

2016-05-19

The neuroendocrine-immune (NEI) regulatory network is a complex system, which plays an indispensable role in the immunity of the host. In the present study, the bioinformatical analysis of the transcriptomic data from oyster Crassostrea gigas and further biological validation revealed that oyster TNF (CgTNF-1 CGI_10018786) could activate the transcription factors NF-κB and HSF (heat shock transcription factor) through MAPK signaling pathway, and then regulate apoptosis, redox reaction, neuro-regulation and protein folding in oyster haemocytes. The activated immune cells then released neurotransmitters including acetylcholine, norepinephrine and [Met(5)]-enkephalin to regulate the immune response by arising the expression of three TNF (CGI_10005109, CGI_10005110 and CGI_10006440) and translocating two NF-κB (Cgp65, CGI_10018142 and CgRel, CGI_10021567) between the cytoplasm and nuclei of haemocytes. Neurotransmitters exhibited the immunomodulation effects by influencing apoptosis and phagocytosis of oyster haemocytes. Acetylcholine and norepinephrine could down-regulate the immune response, while [Met(5)]-enkephalin up-regulate the immune response. These results suggested that the simple neuroendocrine-immune regulatory network in oyster might be activated by oyster TNF and then regulate the immune response by virtue of neurotransmitters, cytokines and transcription factors.

The simple neuroendocrine-immune regulatory network in oyster Crassostrea gigas mediates complex functions

NASA Astrophysics Data System (ADS)

Liu, Zhaoqun; Wang, Lingling; Zhou, Zhi; Sun, Ying; Wang, Mengqiang; Wang, Hao; Hou, Zhanhui; Gao, Dahai; Gao, Qiang; Song, Linsheng

2016-05-01

The neuroendocrine-immune (NEI) regulatory network is a complex system, which plays an indispensable role in the immunity of the host. In the present study, the bioinformatical analysis of the transcriptomic data from oyster Crassostrea gigas and further biological validation revealed that oyster TNF (CgTNF-1 CGI_10018786) could activate the transcription factors NF-κB and HSF (heat shock transcription factor) through MAPK signaling pathway, and then regulate apoptosis, redox reaction, neuro-regulation and protein folding in oyster haemocytes. The activated immune cells then released neurotransmitters including acetylcholine, norepinephrine and [Met5]-enkephalin to regulate the immune response by arising the expression of three TNF (CGI_10005109, CGI_10005110 and CGI_10006440) and translocating two NF-κB (Cgp65, CGI_10018142 and CgRel, CGI_10021567) between the cytoplasm and nuclei of haemocytes. Neurotransmitters exhibited the immunomodulation effects by influencing apoptosis and phagocytosis of oyster haemocytes. Acetylcholine and norepinephrine could down-regulate the immune response, while [Met5]-enkephalin up-regulate the immune response. These results suggested that the simple neuroendocrine-immune regulatory network in oyster might be activated by oyster TNF and then regulate the immune response by virtue of neurotransmitters, cytokines and transcription factors.

A Dopa Decarboxylase Modulating the Immune Response of Scallop Chlamys farreri

PubMed Central

Zhou, Zhi; Yang, Jialong; Wang, Lingling; Zhang, Huan; Gao, Yang; Shi, Xiaowei; Wang, Mengqiang; Kong, Pengfei; Qiu, Limei; Song, Linsheng

2011-01-01

Background Dopa decarboxylase (DDC) is a pyridoxal 5-phosphate (PLP)-dependent enzyme that catalyzes the decarboxylation of L-Dopa to dopamine, and involved in complex neuroendocrine-immune regulatory network. The function for DDC in the immunomodulation remains unclear in invertebrate. Methodology The full-length cDNA encoding DDC (designated CfDDC) was cloned from mollusc scallop Chlamys farreri. It contained an open reading frame encoding a polypeptide of 560 amino acids. The CfDDC mRNA transcripts could be detected in all the tested tissues, including the immune tissues haemocytes and hepatopancreas. After scallops were treated with LPS stimulation, the mRNA expression level of CfDDC in haemocytes increased significantly (5.5-fold, P<0.05) at 3 h and reached the peak at 12 h (9.8-fold, P<0.05), and then recovered to the baseline level. The recombinant protein of CfDDC (rCfDDC) was expressed in Escherichia coli BL21 (DE3)-Transetta, and 1 mg rCfDDC could catalyze the production of 1.651±0.22 ng dopamine within 1 h in vitro. When the haemocytes were incubated with rCfDDC-coated agarose beads, the haemocyte encapsulation to the beads was increased significantly from 70% at 6 h to 93% at 24 h in vitro in comparison with that in the control (23% at 6 h to 25% at 24 h), and the increased haemocyte encapsulation was repressed by the addition of rCfDDC antibody (which is acquired via immunization 6-week old rats with rCfDDC). After the injection of DDC inhibitor methyldopa, the ROS level in haemocytes of scallops was decreased significantly to 0.41-fold (P<0.05) of blank group at 12 h and 0.47-fold (P<0.05) at 24 h, respectively. Conclusions These results collectively suggested that CfDDC, as a homologue of DDC in scallop, modulated the immune responses such as haemocytes encapsulation as well as the ROS level through its catalytic activity, functioning as an indispensable immunomodulating enzyme in the neuroendocrine-immune regulatory network of mollusc. PMID

Recovery of primary sporocysts in vivo in the Schistosoma mansoni/Biomphalaria glabrata model using a simple fixation method suitable for extraction of genomic DNA and RNA.

PubMed

Allienne, Jean-François; Théron, André; Gourbal, Benjamin

2011-09-01

Detailed studies of host/parasite interactions are currently limited because in situ gene sequencing or monitoring of parasite gene expression is so far limited to genes presenting a high loci copy number in the Schistosome genome or a high level of expression. Indeed, how to investigate the host parasite molecular interplay when parasites are not directly accessible in vivo? Here we describe a method to circumvent this problem and to analyze DNA and RNA of Schistosoma mansoni during the interaction with its intermediate snail host Biomphalaria glabrata. We propose a technique for improved DNA and RNA extraction from the intra-molluscan stage of the parasite recovered after fixation of infected snails in Raillet-Henry solution. The extractions can be used for genetic analysis, transcription studies and microsatellite genotyping. Copyright © 2011 Elsevier Inc. All rights reserved.

Antifungal activity of silver nanoparticles in combination with nystatin and chlorhexidine digluconate against Candida albicans and Candida glabrata biofilms.

PubMed

Monteiro, Douglas R; Silva, Sónia; Negri, Melyssa; Gorup, Luiz F; de Camargo, Emerson R; Oliveira, Rosário; Barbosa, Debora B; Henriques, Mariana

2013-11-01

Although silver nanoparticles (SN) have been investigated as an alternative to conventional antifungal drugs in the control of Candida-associated denture stomatitis, the antifungal activity of SN in combination with antifungal drugs against Candida biofilms remains unknown. Therefore, the aim of this study was to evaluate the antifungal efficacy of SN in combination with nystatin (NYT) or chlorhexidine digluconate (CHG) against Candida albicans and Candida glabrata biofilms. The drugs alone or combined with SN were applied on mature Candida biofilms (48 h), and after 24 h of treatment their antibiofilm activities were assessed by total biomass quantification (by crystal violet staining) and colony forming units enumeration. The structure of Candida biofilms was analysed by scanning electron microscopy (SEM) images. The data indicated that SN combined with either NYT or CHG demonstrated synergistic antibiofilm activity, and this activity was dependent on the species and on the drug concentrations used. SEM images showed that some drug combinations were able to disrupt Candida biofilms. The results of this study suggest that the combination of SN with NYT or CHG may have clinical implications in the treatment of denture stomatitis. However, further studies are needed before recommending the use of these drugs safely in clinical situations. © 2013 Blackwell Verlag GmbH.

Biompha-LAMP: A New Rapid Loop-Mediated Isothermal Amplification Assay for Detecting Schistosoma mansoni in Biomphalaria glabrata Snail Host.

PubMed

Gandasegui, Javier; Fernández-Soto, Pedro; Hernández-Goenaga, Juan; López-Abán, Julio; Vicente, Belén; Muro, Antonio

2016-12-01

Schistosomiasis remains one of the most common endemic parasitic diseases affecting over 230 million people worlwide. Schistosoma mansoni is the main species causing intestinal and hepatic schistosomiasis and the fresh water pulmonate snails of the genus Biomphalaria are best known for their role as intermediate hosts of the parasite. The development of new molecular monitoring assays for large-scale screening of snails from transmission sites to detect the presence of schistosomes is an important point to consider for snail control interventions related to schistosomiasis elimination. Our work was focussed on developing and evaluating a new LAMP assay combined with a simple DNA extraction method to detect S. mansoni in experimentally infected snails as a diagnostic tool for field conditions. A LAMP assay using a set of six primers targeting a sequence of S. mansoni ribosomal intergenic spacer 28S-18S rRNA was designed. The detection limit of the LAMP assay was 0.1 fg of S. mansoni DNA at 63°C for 50 minutes. LAMP was evaluated by examining S. mansoni DNA in B. glabrata snails experimentally exposed to miracidia at different times post-exposure: early prepatent period (before cercarial shedding), light infections (snails exposed to a low number of miracidia) and detection of infected snails in pooled samples (within a group of uninfected snails). DNA for LAMP assays was obtained by using a commercial DNA extraction kit or a simple heat NaOH extraction method. We detected S. mansoni DNA in all groups of snails by using no complicated requirement procedure for DNA obtaining. Our LAMP assay, named Biompha-LAMP, is specific, sensitive, rapid and potentially adaptable as a cost-effective method for screening of intermediate hosts infected with S. mansoni in both individual snails and pooled samples. The assay could be suitable for large-scale field surveys for schistosomes control campaigns in endemic areas.

Gα73B is a downstream effector of JAK/STAT signalling and a regulator of Rho1 in Drosophila haematopoiesis.

PubMed

Bausek, Nina; Zeidler, Martin P

2014-01-01

JAK/STAT signalling regulates many essential developmental processes including cell proliferation and haematopoiesis, whereas its inappropriate activation is associated with the majority of myeloproliferative neoplasias and numerous cancers. Furthermore, high levels of JAK/STAT pathway signalling have also been associated with enhanced metastatic invasion by cancerous cells. Strikingly, gain-of-function mutations in the single Drosophila JAK homologue, Hopscotch, result in haemocyte neoplasia, inappropriate differentiation and the formation of melanised haemocyte-derived 'tumour' masses; phenotypes that are partly orthologous to human gain-of-function JAK2-associated pathologies. Here we show that Gα73B, a novel JAK/STAT pathway target gene, is necessary for JAK/STAT-mediated tumour formation in flies. In addition, although Gα73B does not affect haemocyte differentiation, it does regulate haemocyte morphology and motility under non-pathological conditions. We show that Gα73B is required for constitutive, but not injury-induced, activation of Rho1 and for the localisation of Rho1 into filopodia upon haemocyte activation. Consistent with these results, we also show that Rho1 interacts genetically with JAK/STAT signalling, and that wild-type levels of Rho1 are necessary for tumour formation. Our findings link JAK/STAT transcriptional outputs, Gα73B activity and Rho1-dependent cytoskeletal rearrangements and cell motility, therefore connecting a pathway associated with cancer with a marker indicative of invasiveness. As such, we suggest a mechanism by which JAK/STAT pathway signalling may promote metastasis.

Treatment of a critically ill child with disseminated Candida glabrata with a recombinant human antibody specific for fungal heat shock protein 90 and liposomal amphotericin B, caspofungin, and voriconazole.

PubMed

Sutherland, Adam; Ellis, David

2008-07-01

To report a case of fungal sepsis treated prospectively with liposomal amphotericin, caspofungin, and a novel monoclonal antibody specific for candidal heat shock protein 90 (Mycograb, Neutec Pharma, Manchester, UK). Case report. Pediatric intensive care unit in a tertiary care children's hospital. A 7-yr-old male with a history of global developmental delay, epilepsy, and gastroesophageal reflux, who presented to the emergency department with a transdiaphragmatic herniation of bowel and subsequent Candida glabrata infection. Efungumab 1 mg/kg twice daily for 5 days. C-reactive protein fell from 225 mg/L to 99 mg/L, and physiological monitoring parameters improved when Mycograb was used in conjunction with high-dose antifungals. Mycograb therapy was well tolerated, but further experience with this therapy in children is needed.

Flooding modifies the genotoxic effects of pollution on a worm, a mussel and two fish species from the Sava River.

PubMed

Aborgiba, Mustafa; Kostić, Jovana; Kolarević, Stoimir; Kračun-Kolarević, Margareta; Elbahi, Samia; Knežević-Vukčević, Jelena; Lenhardt, Mirjana; Paunović, Momir; Gačić, Zoran; Vuković-Gačić, Branka

2016-01-01

Extreme hydrological events, such as water scarcity and flooding, can modify the effect of other stressors present in aquatic environment, which could result in the significant changes in the ecosystem functioning. Presence and interaction of various stressors (genotoxic pollutants) in the environment can influence the integrity of DNA molecules in aquatic organisms which can be negatively reflected on the individual, population and community levels. Therefore, in this study we have investigated the impact of flooding, in terms of genotoxicity, on organisms belonging to different trophic levels. The study was carried out on the site situated in the lower stretch of the Sava River which faced devastating effects of severe flooding in May 2014. The flooding occurred during our field experiment and this event provided a unique opportunity to assess its influence to the environment. The in situ effects of this specific situation were monitored by measuring physical, chemical and microbiological parameters of water, and by comparing the level of DNA damage in coelomocytes and haemocytes of freshwater worms Branchiura sowerbyi, haemocytes of freshwater mussels Unio tumidus and blood cells of freshwater fish Abramis bjoerkna/Abramis sapa, by means of the comet assay. Our study indicated that the flooding had a significant impact on water quality by decreasing the amount and discharge rate of urban wastewaters but simultaneously introducing contaminants from the nearby fly ash disposal field into river by runoff, which had diverse effects on the level of DNA damage in the studied organisms. This indicates that the assessment of genotoxic pollution in situ is strongly affected by the choice of the bioindicator organism. Copyright © 2015 Elsevier B.V. All rights reserved.

Effective immunosuppression with dexamethasone phosphate in the Galleria mellonella larva infection model resulting in enhanced virulence of Escherichia coli and Klebsiella pneumoniae.

PubMed

Torres, Miquel Perez; Entwistle, Frances; Coote, Peter J

2016-08-01

The aim was to evaluate whether immunosuppression with dexamethasone 21-phosphate could be applied to the Galleria mellonella in vivo infection model. Characterised clinical isolates of Escherichia coli or Klebsiella pneumoniae were employed, and G. mellonella larvae were infected with increasing doses of each strain to investigate virulence in vivo. Virulence was then compared with larvae exposed to increasing doses of dexamethasone 21-phosphate. The effect of dexamethasone 21-phosphate on larval haemocyte phagocytosis in vitro was determined via fluorescence microscopy and a burden assay measured the growth of infecting bacteria inside the larvae. Finally, the effect of dexamethasone 21-phosphate treatment on the efficacy of ceftazidime after infection was also noted. The pathogenicity of K. pneumoniae or E. coli in G. mellonella larvae was dependent on high inoculum numbers such that virulence could not be attributed specifically to infection by live bacteria but also to factors associated with dead cells. Thus, for these strains, G. mellonella larvae do not constitute an ideal infection model. Treatment of larvae with dexamethasone 21-phosphate enhanced the lethality induced by infection with E. coli or K. pneumoniae in a dose- and inoculum size-dependent manner. This correlated with proliferation of bacteria in the larvae that could be attributed to dexamethasone inhibiting haemocyte phagocytosis and acting as an immunosuppressant. Notably, prior exposure to dexamethasone 21-phosphate reduced the efficacy of ceftazidime in vivo. In conclusion, demonstration of an effective immunosuppressant regimen can improve the specificity and broaden the applications of the G. mellonella model to address key questions regarding infection.

Studies on a haemolymph lectin isolated from Rhodnius prolixus and its interaction with Trypanosoma rangeli.

PubMed

Mello, C B; Nigam, Y; Garcia, E S; Azambuja, P; Newton, R P; Ratcliffe, N A

1999-04-01

We demonstrated that in Rhodnius prolixus haemocyte monolayers, both Trypanosoma cruzi and Trypanosoma rangeli are capable of inducing haemocyte/parasite clump formation. We also purified, by one-step affinity chromatography, a haemolymph galactoside-binding lectin from R. prolixus which we believe could play an important role in the development of T. rangeli in the haemocoel of the insect vector. This lectin markedly enhanced the activation of clump formation by T. rangeli in R. prolixus haemocyte monolayers, with an increase in clump size and haemocyte aggregation. The haemolymph lectin also significantly affected the motilitity and survival of T. rangeli culture short forms, but not the long forms, when they were incubated in vitro. This molecule is also one of the few described in insects with agglutination activity independent of calcium ions. The partial N-terminal amino acid sequence of this lectin demonstrated similarity to a bacterial xylulose kinase and in preliminary experiments the purified haemolymph lectin phosphorylated a tyrosine kinase substrate in a dose-dependent manner. The possible role of this haemolymph lectin in the life cycle of T. rangeli is discussed. Copyright 1999 Academic Press.

Genotoxicity testing of two lead-compounds in somatic cells of Drosophila melanogaster.

PubMed

Carmona, Erico R; Creus, Amadeu; Marcos, Ricard

2011-09-18

The in vivo genotoxic activity of two inorganic lead compounds was studied in Drosophila melanogaster by measurement of two different genetic endpoints. We used the wing-spot test and the comet assay. The comet assay was conducted with larval haemocytes. The results from the wing-spot test showed that neither lead chloride, PbCl(2), nor lead nitrate, Pb(NO(3))(2), were able to induce significant increases in the frequency of mutant spots. In addition, the combined treatments with gamma-radiation and PbCl(2) or Pb(NO(3))(2) did not show significant variations in the frequency of the three categories of mutant spots recorded, compared with the frequency induced by gamma-radiation alone. This seems to indicate that the lead compounds tested do not interact with the repair of the genetic damage induced by ionizing radiation. When the lead compounds were evaluated in the in vivo comet assay with haemocytes, Pb(NO(3))(2) was effective in inducing significant increases of DNA damage with a direct dose-response pattern. These results confirm the usefulness of the comet assay with haemocytes as an in vivo model and support the assumption that there is a genotoxic risk associated with lead exposure. Copyright © 2011 Elsevier B.V. All rights reserved.

Domain Organization in Candida glabrata THI6, a Bifunctional Enzyme Required for Thiamin Biosynthesis in Eukaryotes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, Debamita; Chatterjee, Abhishek; Begley, Tadhg P.

2010-11-15

THI6 is a bifunctional enzyme found in the thiamin biosynthetic pathway in eukaryotes. The N-terminal domain of THI6 catalyzes the ligation of the thiamin thiazole and pyrimidine moieties to form thiamin phosphate, and the C-terminal domain catalyzes the phosphorylation of 4-methyl-5-hydroxyethylthiazole in a salvage pathway. In prokaryotes, thiamin phosphate synthase and 4-methyl-5-hydroxyethylthiazole kinase are separate gene products. Here we report the first crystal structure of a eukaryotic THI6 along with several complexes that characterize the active sites responsible for the two chemical reactions. THI6 from Candida glabrata is a homohexamer in which the six protomers form a cage-like structure. Eachmore » protomer is composed of two domains, which are structurally homologous to their monofunctional bacterial counterparts. Two loop regions not found in the bacterial enzymes provide interactions between the two domains. The structures of different protein-ligand complexes define the thiazole and ATP binding sites of the 4-methyl-5-hydroxyethylthiazole kinase domain and the thiazole phosphate and 4-amino-5-hydroxymethyl-2-methylpyrimidine pyrophosphate binding sites of the thiamin phosphate synthase domain. Our structural studies reveal that the active sites of the two domains are 40 {angstrom} apart and are not connected by an obvious channel. Biochemical studies show 4-methyl-5-hydroxyethylthiazole phosphate is a substrate for THI6; however, adenosine diphospho-5{beta}-ethyl-4-methylthiazole-2-carboxylic acid, the product of THI4, is not a substrate for THI6. This suggests that an unidentified enzyme is necessary to produce the substrate for THI6 from the THI4 product.« less

Acetylcholine-Binding Protein in the Hemolymph of the Planorbid Snail Biomphalaria glabrata Is a Pentagonal Dodecahedron (60 Subunits)

PubMed Central

Kapetanopoulos, Katharina; Braukmann, Sandra; Gebauer, Wolfgang; Tenzer, Stefan; Markl, Jürgen

2012-01-01

Nicotinic acetylcholine receptors (nAChR) play important neurophysiological roles and are of considerable medical relevance. They have been studied extensively, greatly facilitated by the gastropod acetylcholine-binding proteins (AChBP) which represent soluble structural and functional homologues of the ligand-binding domain of nAChR. All these proteins are ring-like pentamers. Here we report that AChBP exists in the hemolymph of the planorbid snail Biomphalaria glabrata (vector of the schistosomiasis parasite) as a regular pentagonal dodecahedron, 22 nm in diameter (12 pentamers, 60 active sites). We sequenced and recombinantly expressed two ∼25 kDa polypeptides (BgAChBP1 and BgAChBP2) with a specific active site, N-glycan site and disulfide bridge variation. We also provide the exon/intron structures. Recombinant BgAChBP1 formed pentamers and dodecahedra, recombinant BgAChBP2 formed pentamers and probably disulfide-bridged di-pentamers, but not dodecahedra. Three-dimensional electron cryo-microscopy (3D-EM) yielded a 3D reconstruction of the dodecahedron with a resolution of 6 Å. Homology models of the pentamers docked to the 6 Å structure revealed opportunities for chemical bonding at the inter-pentamer interfaces. Definition of the ligand-binding pocket and the gating C-loop in the 6 Å structure suggests that 3D-EM might lead to the identification of functional states in the BgAChBP dodecahedron. PMID:22916297

Biompha-LAMP: A New Rapid Loop-Mediated Isothermal Amplification Assay for Detecting Schistosoma mansoni in Biomphalaria glabrata Snail Host

PubMed Central

Hernández-Goenaga, Juan; López-Abán, Julio; Vicente, Belén; Muro, Antonio

2016-01-01

Background Schistosomiasis remains one of the most common endemic parasitic diseases affecting over 230 million people worlwide. Schistosoma mansoni is the main species causing intestinal and hepatic schistosomiasis and the fresh water pulmonate snails of the genus Biomphalaria are best known for their role as intermediate hosts of the parasite. The development of new molecular monitoring assays for large-scale screening of snails from transmission sites to detect the presence of schistosomes is an important point to consider for snail control interventions related to schistosomiasis elimination. Our work was focussed on developing and evaluating a new LAMP assay combined with a simple DNA extraction method to detect S. mansoni in experimentally infected snails as a diagnostic tool for field conditions. Methodology/Principal findings A LAMP assay using a set of six primers targeting a sequence of S. mansoni ribosomal intergenic spacer 28S-18S rRNA was designed. The detection limit of the LAMP assay was 0.1 fg of S. mansoni DNA at 63°C for 50 minutes. LAMP was evaluated by examining S. mansoni DNA in B. glabrata snails experimentally exposed to miracidia at different times post-exposure: early prepatent period (before cercarial shedding), light infections (snails exposed to a low number of miracidia) and detection of infected snails in pooled samples (within a group of uninfected snails). DNA for LAMP assays was obtained by using a commercial DNA extraction kit or a simple heat NaOH extraction method. We detected S. mansoni DNA in all groups of snails by using no complicated requirement procedure for DNA obtaining. Conclusions/Significance Our LAMP assay, named Biompha-LAMP, is specific, sensitive, rapid and potentially adaptable as a cost-effective method for screening of intermediate hosts infected with S. mansoni in both individual snails and pooled samples. The assay could be suitable for large-scale field surveys for schistosomes control campaigns in endemic

A Novel Hybrid Iron Regulation Network Combines Features from Pathogenic and Nonpathogenic Yeasts.

PubMed

Gerwien, Franziska; Safyan, Abu; Wisgott, Stephanie; Hille, Fabrice; Kaemmer, Philipp; Linde, Jörg; Brunke, Sascha; Kasper, Lydia; Hube, Bernhard

2016-10-18

Iron is an essential micronutrient for both pathogens and their hosts, which restrict iron availability during infections in an effort to prevent microbial growth. Successful human pathogens like the yeast Candida glabrata have thus developed effective iron acquisition strategies. Their regulation has been investigated well for some pathogenic fungi and in the model organism Saccharomyces cerevisiae, which employs an evolutionarily derived system. Here, we show that C. glabrata uses a regulation network largely consisting of components of the S. cerevisiae regulon but also of elements of other pathogenic fungi. Specifically, similarly to baker's yeast, Aft1 is the main positive regulator under iron starvation conditions, while Cth2 degrades mRNAs encoding iron-requiring enzymes. However, unlike the case with S. cerevisiae, a Sef1 ortholog is required for full growth under iron limitation conditions, making C. glabrata an evolutionary intermediate to SEF1-dependent fungal pathogens. Therefore, C. glabrata has evolved an iron homeostasis system which seems to be unique within the pathogenic fungi. The fungus Candida glabrata represents an evolutionarily close relative of the well-studied and benign baker's yeast and model organism Saccharomyces cerevisiae On the other hand, C. glabrata is an important opportunistic human pathogen causing both superficial and systemic infections. The ability to acquire trace metals, in particular, iron, and to tightly regulate this process during infection is considered an important virulence attribute of a variety of pathogens. Importantly, S. cerevisiae uses a highly derivative regulatory system distinct from those of other fungi. Until now, the regulatory mechanism of iron homeostasis in C. glabrata has been mostly unknown. Our study revealed a hybrid iron regulation network that is unique to C. glabrata and is placed at an evolutionary midpoint between those of S. cerevisiae and related fungal pathogens. We thereby

The Drosophila cell adhesion molecule Neuroglian regulates Lissencephaly-1 localisation in circulating immunosurveillance cells.

PubMed

Williams, Michael J

2009-03-25

When the parasitoid wasp Leptopilina boulardi lays its eggs in Drosophila larvae phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. This requires these circulating immunosurveillance cells (haemocytes) to change from a non-adhesive to an adhesive state enabling them to bind to the invader. Interestingly, attachment of leukocytes, platelets, and insect haemocytes requires the same adhesion complexes as epithelial and neuronal cells. Here evidence is presented showing that the Drosophila L1-type cell adhesion molecule Neuroglian (Nrg) is required for haemocytes to encapsulate L. boulardi wasp eggs. The amino acid sequence FIGQY containing a conserved phosphorylated tyrosine is found in the intracellular domain of all L1-type cell adhesion molecules. This conserved tyrosine is phosphorylated at the cell periphery of plasmatocytes and lamellocytes prior to parasitisation, but dephosphorylated after immune activation. Intriguingly, another pool of Nrg located near the nucleus of plasmatocytes remains phosphorylated after parasitisation. In mammalian neuronal cells phosphorylated neurofascin, another L1-type cell adhesion molecule interacts with a nucleokinesis complex containing the microtubule binding protein lissencephaly-1 (Lis1) 1. Interestingly in plasmatocytes from Nrg mutants the nucleokinesis regulating protein Lissencephaly-1 (Lis1) fails to localise properly around the nucleus and is instead found diffuse throughout the cytoplasm and at unidentified perinuclear structures. After attaching to the wasp egg control plasmatocytes extend filopodia laterally from their cell periphery; as well as extending lateral filopodia plasmatocytes from Nrg mutants also extend many filopodia from their apical surface. The Drosophila cellular adhesion molecule Neuroglian is expressed in haemocytes and its activity is required for the encapsulation of L. boularli eggs. At the cell periphery of haemocytes Neuroglian may be

The Drosophila cell adhesion molecule Neuroglian regulates Lissencephaly-1 localisation in circulating immunosurveillance cells

PubMed Central

Williams, Michael J

2009-01-01

Background When the parasitoid wasp Leptopilina boulardi lays its eggs in Drosophila larvae phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. This requires these circulating immunosurveillance cells (haemocytes) to change from a non-adhesive to an adhesive state enabling them to bind to the invader. Interestingly, attachment of leukocytes, platelets, and insect haemocytes requires the same adhesion complexes as epithelial and neuronal cells. Results Here evidence is presented showing that the Drosophila L1-type cell adhesion molecule Neuroglian (Nrg) is required for haemocytes to encapsulate L. boulardi wasp eggs. The amino acid sequence FIGQY containing a conserved phosphorylated tyrosine is found in the intracellular domain of all L1-type cell adhesion molecules. This conserved tyrosine is phosphorylated at the cell periphery of plasmatocytes and lamellocytes prior to parasitisation, but dephosphorylated after immune activation. Intriguingly, another pool of Nrg located near the nucleus of plasmatocytes remains phosphorylated after parasitisation. In mammalian neuronal cells phosphorylated neurofascin, another L1-type cell adhesion molecule interacts with a nucleokinesis complex containing the microtubule binding protein lissencephaly-1 (Lis1) [1]. Interestingly in plasmatocytes from Nrg mutants the nucleokinesis regulating protein Lissencephaly-1 (Lis1) fails to localise properly around the nucleus and is instead found diffuse throughout the cytoplasm and at unidentified perinuclear structures. After attaching to the wasp egg control plasmatocytes extend filopodia laterally from their cell periphery; as well as extending lateral filopodia plasmatocytes from Nrg mutants also extend many filopodia from their apical surface. Conclusion The Drosophila cellular adhesion molecule Neuroglian is expressed in haemocytes and its activity is required for the encapsulation of L. boularli eggs. At the cell periphery of

Behavioural and immunological responses to an immune challenge in Octopus vulgaris.

PubMed

Locatello, Lisa; Fiorito, Graziano; Finos, Livio; Rasotto, Maria B

2013-10-02

Behavioural and immunological changes consequent to stress and infection are largely unexplored in cephalopods, despite the wide employment of species such as Octopus vulgaris in studies that require their manipulation and prolonged maintenance in captivity. Here we explore O. vulgaris behavioural and immunological (i.e. haemocyte number and serum lysozyme activity) responses to an in vivo immune challenge with Escherichia coli lipopolysaccharides (LPS). Behavioural changes of immune-treated and sham-injected animals were observed in both sight-allowed and isolated conditions, i.e. visually interacting or not with a conspecific. Immune stimulation primarily caused a significant increase in the number of circulating haemocytes 4h after the treatment, while serum lysozyme activity showed a less clear response. However, the effect of LPS on the circulating haemocytes begins to vanish 24h after injection. Our observations indicate a significant change in behaviour consequent to LPS administration, with treated octopuses exhibiting a decrease of general activity pattern when kept in the isolated condition. A similar decrease was not observed in the sight-allowed condition, where we noticed a specific significant reduction only in the time spent to visually interact with the conspecific. Overall, significant, but lower, behavioural and immunological effects of injection were detected also in sham-injected animals, suggesting a non-trivial susceptibility to manipulation and haemolymph sampling. Our results gain importance in light of changes of the regulations for the use of cephalopods in scientific procedures that call for the prompt development of guidelines, covering many aspects of cephalopod provision, maintenance and welfare. © 2013.

Milbemycins: More than Efflux Inhibitors for Fungal Pathogens

PubMed Central

Silva, Luis Vale; Sanguinetti, Maurizio; Vandeputte, Patrick; Torelli, Riccardo; Rochat, Bertrand

2013-01-01

Existing antifungal agents are still confronted to activities limited to specific fungal species and to the development of resistance. Several improvements are possible either by tackling and overcoming resistance or exacerbating the activity of existing antifungal agents. In Candida glabrata, azole resistance is almost exclusively mediated by ABC transporters (including C. glabrata CDR1 [CgCDR1] and CgCDR2) via gain-of-function mutations in the transcriptional activator CgPDR1 or by mitochondrial dysfunctions. We also observed that azole resistance was correlating with increasing virulence and fitness of C. glabrata in animal models of infection. This observation motivated the re-exploitation of ABC transporter inhibitors as a possible therapeutic intervention to decrease not only the development of azole resistance but also to interfere with the virulence of C. glabrata. Milbemycins are known ABC transporter inhibitors, and here we used commercially available milbemycin A3/A4 oxim derivatives to verify this effect. As expected, the derivatives were inhibiting C. glabrata efflux with the highest activity for A3 oxim below 1 μg/ml. More surprising was that oxim derivatives had intrinsic fungicidal activity above 3.2 μg/ml, thus highlighting effects additional to the efflux inhibition. Similar values were obtained with C. albicans. Our data show that the fungicidal activity could be related to reactive oxygen species formation in these species. Transcriptional analysis performed both in C. glabrata and C. albicans exposed to A3 oxim highlighted a core of commonly regulated genes involved in stress responses, including genes involved in oxidoreductive processes, protein ubiquitination, and vesicle trafficking, as well as mitogen-activated protein kinases. However, the transcript profiles contained also species-specific signatures. Following these observations, experimental treatments of invasive infections were performed in mice treated with the commercial A3/A4

The effect of the combination of two biological control agents, Mirabilis jalapa and Bacillus thuringiensis, to Spodoptera litura's immune response and their mortality

NASA Astrophysics Data System (ADS)

Maulina, Dina; Anggraeni, Tjandra

2014-03-01

Biological control provides a safer alternative to reduce the population of agricultural pest. Mirabilis jalapa is one of many promising biopesticides which contains chemical substances that have a feeding deterrent property against insects. This biopesticide may not kill insect directly but will weaken their overall physiological condition. In this study, we investigated the immune response of common pestSpodoptera litura after exposure of M. jalapa extract. We also used Bacillus thuringiensis (Bt) delta endotoxin (LC50) on 3 hours after exposure of M. jalapa extract to see the synergism properties of both biopesticide agents. Microscopic observation revealed that at least 5 types of haemocyte were found in S. litura. In control group, plasmatocyte were found at 59.98%, prohaemocyte 20.73%, granullar cell 12.74%, oenocytoid 3.33% and spherule cell 3.20%. These proportion was differ significantly in the treatment group. Exposure to 0.1% and 0.2%(w/v) of M. jalapa extract increased the total number of haemocytes as much as 38.08% and 64.15% respectively. In contrast, exposure to 0.4% and 0.8%(w/v) reduced the number of haemocytes to 37.02% and 51.04% respectively. In term of phagocytic activity, the proportion of phagocytosing cells were 47.62% in control group, and in 0.1% and 0.2% (w/v) M. jalapa treatment group the proportion decreased to 28% and 26.88% respectively. In the concentration of 0.4% and 0.8%, phagocytic activity did not occur. Addition of biological agents Bt (LC50 concentration) to see mortality 3 hours after M. jalapa application did not show significant differences. S. litura mortality rate were found only 50%; this suggests that the combination of M. jalapa and Bt biopesticides in 3-hour intervals within 24 hours showed no increase in mortality.

A Novel Hybrid Iron Regulation Network Combines Features from Pathogenic and Nonpathogenic Yeasts

PubMed Central

Gerwien, Franziska; Safyan, Abu; Wisgott, Stephanie; Hille, Fabrice; Kaemmer, Philipp; Linde, Jörg; Brunke, Sascha; Kasper, Lydia

2016-01-01

ABSTRACT Iron is an essential micronutrient for both pathogens and their hosts, which restrict iron availability during infections in an effort to prevent microbial growth. Successful human pathogens like the yeast Candida glabrata have thus developed effective iron acquisition strategies. Their regulation has been investigated well for some pathogenic fungi and in the model organism Saccharomyces cerevisiae, which employs an evolutionarily derived system. Here, we show that C. glabrata uses a regulation network largely consisting of components of the S. cerevisiae regulon but also of elements of other pathogenic fungi. Specifically, similarly to baker’s yeast, Aft1 is the main positive regulator under iron starvation conditions, while Cth2 degrades mRNAs encoding iron-requiring enzymes. However, unlike the case with S. cerevisiae, a Sef1 ortholog is required for full growth under iron limitation conditions, making C. glabrata an evolutionary intermediate to SEF1-dependent fungal pathogens. Therefore, C. glabrata has evolved an iron homeostasis system which seems to be unique within the pathogenic fungi. PMID:27795405

Inhibitory effect of alpha-mangostin on Candida biofilms.

PubMed

Kaomongkolgit, Ruchadaporn; Jamdee, Kusuma

2017-04-01

The objective of this study was to determine the inhibitory effect of alpha-mangostin on Candida biofilms. Candida species including Candida albicans, Candida krusei, Candida tropicalis, and Candida glabrata were tested. Candida biofilms were formed in flat-bottomed 96-well microtiter plates. The metabolic activity of cells within biofilms was quantified using the XTT assay. The results demonstrated that alpha-mangostin showed a significant anti-biofilm effect on both developing biofilms and preformed biofilms of Candida species. It may be concluded that alpha-mangostin could be an anti-biofilm agent against Candida species. Further in vivo investigations are needed to uncover the therapeutic values of this medicinal plant.

Pathology Associated with White Spot Virus (WSV) Infection in Wild Broodstock of Tiger Prawns (Penaeus monodon)

PubMed Central

Kua, Beng Chu; Rashid, Noraziah Mat

2012-01-01

A total of six wild broodstocks of tiger prawns, Penaeus monodon, were found positive for White Spot Virus (WSV) with an IQ2000 detection kit. Using histopathology, the intranuclear inclusion of haemocyte due to WSV infection was observed in the epithelium cells of the antennal gland, stomach and gills. This result confirmed that the wild broodstocks were positive with WSV without showing any white spot. Additionally, histopathological examination also revealed an accumulation of haemocytes around the hepatopancreatic tubules resulting from bacterial infection. Encapsulation and nodule formation, as well as related necrosis, were also observed around the hepatopancreatic tubules infected with a metazoan parasite. Encysted tylocephalum larval cestodes were observed in the hepatopancreas, with haemocytic aggregation being observed around the infected tubules. These findings showed some bacterial and parasitic infections which, in addition to the viral infection itself, could contribute to the 80% mortality rate in wild broodstocks infected with WSV. PMID:24575228

Sex versus parthenogenesis; immune function in a facultatively parthenogenetic phasmatid (Extatosoma tiaratum).

PubMed

Alavi, Yasaman; Elgar, Mark Adrian; Jones, Therésa Melanie

2017-07-01

Facultative parthenogenetic species, in which females can alternate between sex and parthenogenesis, are useful models to investigate the costs and benefits of sex and parthenogenesis, an ongoing issue in biology. The necessary empirical studies comparing the outcomes of alternative reproductive modes on life history traits are rare and focus mainly on traits directly associated with reproductive fitness. Immune function determines the ability of individuals to defend themselves against injury and disease and is therefore likely to have a significant impact on fitness. Here, we used the facultatively parthenogenetic Australian phasmatid, Extatosoma tiaratum, to investigate the effect of both maternal and offspring mode of conception (sexual or parthenogenetic) on offspring immune function (haemocyte concentration, lytic activity and phenoloxidase activity). We show that when parthenogenesis persists beyond one generation, it has negative effects on immune response in terms of haemocyte concentration and lytic activity. Phenoloxidase activity positively correlates with the level of microsatellite heterozygosity. Moreover, immune response decreases across consecutive sampling weeks, suggesting there are physiological constraints with respect to mounting immune responses in close time intervals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Localization of Tyrosine Hydroxylase-like Immunoreactivity in the Nervous Systems of Biomphalaria glabrata and Biomphalaria alexandrina, Intermediate Hosts for Schistosomiasis

PubMed Central

Vallejo, Deborah; Habib, Mohammed R.; Delgado, Nadia; Vaasjo, Lee O.; Croll, Roger P.; Miller, Mark W.

2014-01-01

Planorbid snails of the genus Biomphalaria are major intermediate hosts for the digenetic trematode parasite Schistosoma mansoni. Evidence suggests that levels of the neurotransmitter dopamine (DA) are reduced during the course of S. mansoni multiplication and transformation within the snail. This investigation used immunohistochemical methods to localize tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of catecholamines, in the nervous system of Biomphalaria. The two species examined, Biomphalaria glabrata and Biomphalaria alexandrina, are the major intermediate hosts for S. mansoni in sub-Saharan Africa, where more than 90% of global cases of human intestinal schistosomiasis occur. TH-like immunoreactive (THli) neurons were distributed throughout the central nervous system (CNS) and labeled fibers were present in all commissures, connectives, and nerves. Some asymmetries were observed, including a large distinctive neuron (LPeD1) in the pedal ganglion described previously in several pulmonates. The majority of TH-like immunoreactive neurons were detected in the peripheral nervous system (PNS), especially in lip and foot regions of the anterior integument. Independent observations supporting the dopaminergic phenotype of THli neurons included 1) block of LPeD1 synaptic signaling by the D2/3 antagonist sulpiride, and 2) the similar localization of aqueous aldehyde (FaGlu) induced fluorescence. The distribution of THli neurons indicates that, as in other gastropods, dopamine functions as a sensory neurotransmitter and in the regulation of feeding and reproductive behaviors in Biomphalaria. It is hypothesized that infection could stimulate transmitter release from dopaminergic sensory neurons and that dopaminergic signaling could contribute to modifications of both host and parasite behavior. PMID:24477836

The synthesis, antifungal and apoptotic effects of triazole-oxadiazoles against Candida species.

PubMed

Çavuşoğlu, Betül Kaya; Yurttaş, Leyla; Cantürk, Zerrin

2018-01-20

In search of potent and safe antifungal agents, herein, we report the synthesis, characterization and biological activities of triazole-oxadiazole compounds. The structural verification of the molecules was carried out by 1 H NMR, 13 C NMR and mass spectral data. The in vitro antifungal and apoptotic activity were investigated against C. albicans, C. parapsilosis, C. krusei and C. glabrata. The compounds namely N-(4-nitrophenyl)-2-[(5-(2-((4-methyl-4H-1,2,4-triazol-3-yl)thio)ethyl)-1,3,4-oxadiazol-2-yl)thio]acetamide (4e) and N-(6-fluorobenzothiazol-2-yl)-2-[(5-(2-((4-methyl-4H-1,2,4-triazol-3-yl)thio)ethyl)-1,3,4-oxadiazol-2-yl)thio]acetamide (4i) were detected as the most potent compounds against C. albicans and C. glabrata (MIC 90  = 62.5 μg/mL). According to studies on their mechanism of action, it was confirmed that compound 4i has apoptotic effect on four Candida via Annexin V-PI with flow cytometry. The MTT assay revealed that all compounds were determined to be non-toxic against healthy cells in the tested concentrations. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

[Susceptibility to azoles and amphotericin B of isolates of Candida spp. Experience of a university health network, between 2004 and 2010].

PubMed

Porte, Lorena; León, Pilar; Gárate, Cynthia; Guzmán, Ana María; Labarca, Jaime; García, Patricia

2012-04-01

To describe antifungal susceptibility testing surveillance (December 2004-September 2010) in Candida spp., for amphotericin B, fluconazole and voriconazole, at the Laboratorio de Microbiología, Pontificia Universidad Católica de Chile. The study was performed utilizing E test and included yeasts from invasive origin and isolates in which antifungal susceptibility testing was asked for by the patient's physician. The yeasts were mainly recovered from urine samples (n: 64), blood cultures (n: 51) and secretions (n: 24). Two hundred ninety three isolates were studied: C. albicans (38%), C. glabrata (30%), C. tropicalis (11%), C. parapsilosis (10%), C. krusei (4%) and others (7%). All Candida species were 100% susceptible to amphotericin B, except C. krusei (1/12). Fluconazole's global susceptibility in C. albicans was 91.8%, but 100% in isolates from blood cultures versus 76% in isolates from urine. C. tropicalis was 93.9% susceptible to fluconazole, C. parapsilosis, 90% and C. glabrata 30.3%. C. krusei had no susceptible isolates to fluconazole. Voriconazole resistance was mainly present in C. glabrata (11.5%). We recommend the study of antifungal susceptibility in isolates from invasive origin, selected urine strains and C. glabrata. Fluconazole remains effective in C. albicans from blood.

L-arginine enhances immunity to parasitoids in Drosophila melanogaster and increases NO production in lamellocytes.

PubMed

Kraaijeveld, Alex R; Elrayes, Naji P; Schuppe, Hansjürgen; Newland, Philip L

2011-08-01

Drosophila melanogaster was used as a model system to explore the link between nutrition and immunity, and to investigate the role of nitric oxide (NO) in enhancing immunity following dietary enhancement with L-arginine. First, we show that adding L-arginine to the food medium increases the ability of D. melanogaster larvae to encapsulate the eggs of the parasitoid Asobara tabida. Secondly, we show that the increase in immunity is specific to L-arginine, and not to an enhanced calorific content, and that immunity decreases when larvae are fed food with added L-NAME, an inhibitor of nitric oxide synthase. Finally, we show that parasitised larvae fed L-arginine have increased haemocyte numbers, and that the lamellocytes (haemocytes which play a key role in encapsulation) show evidence of an increased production of NO. These results suggest that NO plays a key role in immunity and that the effect of NO is mostly targeted via the lamellocytes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Host ploidy, parasitism and immune defence in a coevolutionary snail-trematode system.

PubMed

Osnas, E E; Lively, C M

2006-01-01

We studied the role of host ploidy and parasite exposure on immune defence allocation in a snail-trematode system (Potamopyrgus antipodarum-Microphallus sp.). In the field, haemocyte (the defence cell) concentration was lowest in deep-water habitats where infection is relatively low and highest in shallow-water habitats where infection is common. Because the frequency of asexual triploid snails is positively correlated with depth, we also experimentally studied the role of ploidy by exposing both diploid sexual and triploid asexual snails to Microphallus eggs. We found that triploid snails had lower haemocyte concentrations than did diploids in both parasite-addition and parasite-free treatments. We also found that both triploids and diploids increased their numbers of large granular haemocytes at similar rates after parasite exposure. Because triploid P. antipodarum have been shown to be more resistant to allopatric parasites than diploids, the current results suggest that the increased resistance of triploids is because of intrinsic genetic properties rather than to greater allocation to defence cells. This finding is consistent with recent theory on the advantages of increased ploidy for hosts combating coevolving parasites.

Melatonin: a possible link between the presence of artificial light at night and reductions in biological fitness

PubMed Central

Jones, Therésa M.; Durrant, Joanna; Michaelides, Ellie B.; Green, Mark P.

2015-01-01

The mechanisms underpinning the ecological impacts of the presence of artificial night lighting remain elusive. One suspected underlying cause is that the presence of light at night (LAN) supresses nocturnal production of melatonin, a key driver of biological rhythm and a potent antioxidant with a proposed role in immune function. Here, we briefly review the evidence for melatonin as the link between LAN and changes in behaviour and physiology. We then present preliminary data supporting the potential for melatonin to act as a recovery agent mitigating the negative effects of LAN in an invertebrate. Adult crickets (Teleogryllus commodus), exposed to constant illumination, were provided with dietary melatonin (concentrations: 0, 10 or 100 µg ml−1) in their drinking water. We then compared survival, lifetime fecundity and, over a 4-week period, immune function (haemocyte concentration, lysozyme-like and phenoloxidase (PO) activity). Melatonin supplementation was able only partially to mitigate the detrimental effects of LAN: it did not improve survival or fecundity or PO activity, but it had a largely dose-dependent positive effect on haemocyte concentration and lysozyme-like activity. We discuss the implications of these relationships, as well as the usefulness of invertebrates as model species for future studies that explore the effects of LAN. PMID:25780235

Antioxidant and antigenotoxic properties of CeO2 NPs and cerium sulphate: Studies with Drosophila melanogaster as a promising in vivo model.

PubMed

Alaraby, Mohamed; Hernández, Alba; Annangi, Balasubramanyam; Demir, Esref; Bach, Jordi; Rubio, Laura; Creus, Amadeu; Marcos, Ricard

2015-01-01

Although in vitro approaches are the most used for testing the potential harmful effects of nanomaterials, in vivo studies produce relevant information complementing in vitro data. In this context, we promote the use of Drosophila melanogaster as a suitable in vivo model to characterise the potential risks associated to nanomaterials exposure. The main aim of this study was to evaluate different biological effects associated to cerium oxide nanoparticles (Ce-NPs) and cerium (IV) sulphate exposure. The end-points evaluated were egg-to-adult viability, particles uptake through the intestinal barrier, gene expression and intracellular reactive oxygen species (ROS) production by haemocytes, genotoxicity and antigenotoxicity. Transmission electron microscopy images showed internalisation of Ce-NPs by the intestinal barrier and haemocytes, and significant expression of Hsp genes was detected. In spite of these findings, neither toxicity nor genotoxicity related to both forms of cerium were observed. Interestingly, Ce-NPs significantly reduced the genotoxic effect of potassium dichromate and the intracellular ROS production. No morphological malformations were detected after larvae treatment. This study highlights the importance of D. melanogaster as animal model in the study of the different biological effects caused by nanoparticulated materials, at the time that shows its usefulness to study the role of the intestinal barrier in the transposition of nanomaterials entering via ingestion.

Inhibiting fungal multidrug resistance by disrupting an activator-Mediator interaction.

PubMed

Nishikawa, Joy L; Boeszoermenyi, Andras; Vale-Silva, Luis A; Torelli, Riccardo; Posteraro, Brunella; Sohn, Yoo-Jin; Ji, Fei; Gelev, Vladimir; Sanglard, Dominique; Sanguinetti, Maurizio; Sadreyev, Ruslan I; Mukherjee, Goutam; Bhyravabhotla, Jayaram; Buhrlage, Sara J; Gray, Nathanael S; Wagner, Gerhard; Näär, Anders M; Arthanari, Haribabu

2016-02-25

Eukaryotic transcription activators stimulate the expression of specific sets of target genes through recruitment of co-activators such as the RNA polymerase II-interacting Mediator complex. Aberrant function of transcription activators has been implicated in several diseases. However, therapeutic targeting efforts have been hampered by a lack of detailed molecular knowledge of the mechanisms of gene activation by disease-associated transcription activators. We previously identified an activator-targeted three-helix bundle KIX domain in the human MED15 Mediator subunit that is structurally conserved in Gal11/Med15 Mediator subunits in fungi. The Gal11/Med15 KIX domain engages pleiotropic drug resistance transcription factor (Pdr1) orthologues, which are key regulators of the multidrug resistance pathway in Saccharomyces cerevisiae and in the clinically important human pathogen Candida glabrata. The prevalence of C. glabrata is rising, partly owing to its low intrinsic susceptibility to azoles, the most widely used antifungal agent. Drug-resistant clinical isolates of C. glabrata most commonly contain point mutations in Pdr1 that render it constitutively active, suggesting that this transcriptional activation pathway represents a linchpin in C. glabrata multidrug resistance. Here we perform sequential biochemical and in vivo high-throughput screens to identify small-molecule inhibitors of the interaction of the C. glabrata Pdr1 activation domain with the C. glabrata Gal11A KIX domain. The lead compound (iKIX1) inhibits Pdr1-dependent gene activation and re-sensitizes drug-resistant C. glabrata to azole antifungals in vitro and in animal models for disseminated and urinary tract C. glabrata infection. Determining the NMR structure of the C. glabrata Gal11A KIX domain provides a detailed understanding of the molecular mechanism of Pdr1 gene activation and multidrug resistance inhibition by iKIX1. We have demonstrated the feasibility of small-molecule targeting of a

Effectivity of immunostimulant from Zoothamnium penaei protein membrane for decreasing the mortality rate of white shrimp (Litopenaeus vannamei) in traditional plus pond

NASA Astrophysics Data System (ADS)

Mahasri, G.; Kusdarwati, R.; Kismiyati; Rozi; Gustrifandi, H.

2018-04-01

The purpose of this research was to analys immunogenic membrane protein as immunostimulant development material to control the mortality of white shrimp in traditional plus pond. This research was designed to use explorative experiment and experimental laboratory methods which used completed random sampling design. Collected data was analyzed with analysis of variance for examination of survival rate (SR), total haemocyte count (THC) and differensial haemocyte Count (DHC). The research divided into 2 part of riset: (1) Identification, cultivation Zoothamnium penaei, analysed of membrane protein by SDS-PAGE, (2) Field test protein membran on Survival Rate level, immune response (THC and/or DHC level) and infestation of Zoothamnium penaei in traditional plus pond. The result showed that there were seven bands membrane protein of Zoothamnium penaei with molecular weight 38 kDa, 48 kDa, 67 kDa, 71 kDa, 77 kDa, 98 kDa dan 104 kDa by using SDS-PAGE. Immunogenicity tested decrease by using ELISA and western blotting there are only found three bands with molecular weight 38 kDa, 48 kDa dan 67 kDa. The membrane protein could increase the immun respons and decrease the mortality, by subsequenly, it could increase the survival rate from 17% until 68% and pressured the parasite infestation of white shrimp.

Ocean acidification stimulates alkali signal pathway: A bicarbonate sensing soluble adenylyl cyclase from oyster Crassostrea gigas mediates physiological changes induced by CO2 exposure.

PubMed

Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Wang, Hao; Jiang, Shuai; Chen, Hao; Wang, Lingling; Song, Linsheng

2016-12-01

Ocean acidification (OA) has been demonstrated to have severe effects on marine organisms, especially marine calcifiers. However, the impacts of OA on the physiology of marine calcifiers and the underlying mechanisms remain unclear. Soluble adenylyl cyclase (sAC) is an acid-base sensor in response to [HCO 3 - ] and an intracellular source of cyclic AMP (cAMP). In the present study, an ortholog of sAC was identified from pacific oyster Crassostrea gigas (designated as CgsAC) and the catalytic region of CgsAC was cloned and expressed. Similar to the native CgsAC from gill tissues, the recombinant CgsAC protein (rCgsAC) exhibited [HCO 3 - ] mediated cAMP-forming activity, which could be inhibited by a small molecule KH7. After 16days of CO 2 exposure (pH=7.50), the mRNA transcripts of CgsAC increased in muscle, mantle, hepatopancreas, gill, male gonad and haemocytes, and two truncated CgsAC forms of 45kD and 20kD were produced. Cytosolic CgsAC could be translocated from the cytoplasm and nuclei to the membrane in response to CO 2 exposure. Besides, CO 2 exposure could increase the production of cAMP and intracellular pH of haemocytes, which was regulated by CgsAC (p<0.05), suggesting the existence of a [HCO 3 - ]/CgsAC/cAMP signal pathway in oyster. The elevated CO 2 could induce an increase of ROS level (p<0.05) and a decrease of phagocytic rate of haemocytes (p<0.05), which could be inhibited by KH7. The results collectively suggest that CgsAC is an important acid-base sensor in oyster and the [HCO 3 - ]/CgsAC/cAMP signal pathway might be responsible for intracellular alkalization effects on oxidative phosphorylation and innate immunity under CO 2 exposure. The changes of intracellular pH, ROS, and phagocytosis mediated by CgsAC might help us to further understand the effects of ocean acidification on marine calcifiers. Copyright © 2016 Elsevier B.V. All rights reserved.

Time series analysis of the transcriptional responses of Biomphalaria glabrata throughout the course of intramolluscan development of Schistosoma mansoni and Echinostoma paraensei

PubMed Central

Hanington, Patrick C.; Lun, Cheng-Man; Adema, Coen M; Loker, Eric S

2010-01-01

Successful colonization of a compatible snail host by a digenetic trematode miracidium initiates a complex, proliferative development program requiring weeks to reach culmination in the form of production of cercariae which, once started, may persist for the remainder of the life span of the infected snail. How are such proliferative and invasive parasites able to circumvent host defenses and establish chronic infections? Using a microarray designed to monitor the internal defense and stress-related responses of the freshwater snail Biomphalaria glabrata, we have undertaken a time course study to monitor snail responses following exposure to two different trematode species to which the snail is susceptible: the medically important Schistosoma mansoni, exemplifying sporocyst production in its larval development, or Echinostoma paraensei, representing an emphasis on rediae production in its larval development. We sampled eight time points (0.5, 1, 2, 4, 8, 16 and 32 days p.i.) that cover the period required for cercariae to be produced. Following exposure to S. mansoni, there was a preponderance of up-regulated over down-regulated array features through 2 days p.i. but by 4 days p.i. and thereafter, this pattern was strongly reversed. For E. paraensei, there was a preponderance of down-regulated array features over up-regulated features at even 0.5 days p.i., a pattern that persists throughout the course of infection except for 1 day p.i., when up-regulated array features slightly outnumbered down-regulated features. Examination of particular array features revealed several that were up-regulated by both parasites early in the course of infection and one, fibrinogen related protein 4 (FREP 4), that remained significantly elevated throughout the course of infection with either parasite, effectively serving as a marker of infection. Many defense-related transcripts were persistently down-regulated, including several fibrinogen-containing lectins and homologs of

Responses of prophenoloxidase system and related defence parameters of Litopenaeus vannamei to low salinity

NASA Astrophysics Data System (ADS)

Pan, Luqing; Xie, Peng; Hu, Fawen

2010-09-01

In this study, we investigated the effects of low salinity (26 and 21) on the prophenoloxidase (proPO) system and related defence parameters in the shrimp Litopenaeus vannamei. The results showed that low salinity induced a significant increase of dopamine (DA) concentration in haemolymph at 6 h of the experiment; on the other hand, total haemocyte count (THC), differential haemocyte count (DHC) and PO activity decreased over time to the lowest level at 24 h and remained low thereafter. Serine Protease (SP) and Proteinase Inhibitor (PI) activity in the two lower salinity treatments decreased to the lowest level at 12 and 24 h, respectively, and both recovered to the control level at 72 h. In contrast, α2- macroglobulin (α2M) activity in the two lower salinity treatments peaked at 24 h and then decreased to the control level at 72 h. Therefore, it may be concluded that stress-induced DA plays an important temporary role in neurotransmission and causes immune response in L. vannamei in adapting to salinity changes.

Antifungal susceptibilities of Candida species isolated from the patients with vaginal candidiasis.

PubMed

Nagashima, Masahito; Yamagishi, Yuka; Mikamo, Hiroshige

2016-02-01

There have been the current Japanese data on susceptibility testing for Candida isolates from vaginal candidiasis. The in vitro activities of therapeutic antifungal drugs for vulvovaginal candidiasis (VVC); miconazole (MCZ), itraconazole (ITCZ), fluconazole (FLCZ), clotrimazole (CTZ), oxiconazole (OCZ), isoconazole (ICZ) and bifonazole (BFZ) against vaginal isolates. Fifty-four strains Candida albicans and 19 strains of Candida glabrata were evaluated using a broth microdilution method specified by Clinical Laboratories Standard Institute (CLSI) document M27-A3. The MIC90 of each drug, MCZ, ITCZ, FLCZ, CTZ, OCZ, ICZ and BFZ, against C. albicans and C. glabrata isolates were 0.25, 0.12, 1, 0.06, 0.12, 0.12 and 1 μg/ml and 1, 1, 8, 0.5, 0.25, 0.5 and 1 μg/ml respectively. The activities of these drugs, except for BFZ, against C. glabrata were lower than that of C. albicans. There was one azole-resistant isolate in C. glabrata of which MIC of FLCZ is > 64 μg/ml and this isolate had cross resistance to other antifungal drugs tested. These results suggest that antifungal drugs for treatment of VVC continues to have potent antifungal activities against C. albicans and C. glabrata isolates from vaginitis. CTZ, OCZ and ICZ susceptibility of FLCZ low susceptibility C. glabrata are relatively higher than MCZ, ITCZ and FLCZ. Copyright © 2015. Published by Elsevier Ltd.

Resistance to Schistosoma mansoni by transplantation of APO Biomphalaria tenagophila.

PubMed

Barbosa, L; Caldeira, R L; Carvalho, O S; Vidigal, T H D A; Jannotti-Passos, L K; Coelho, P M Z

2006-05-01

Transplantation of the haematopoietic organ from Biomphalaria tenagophila (Taim strain, RS, Brazil), resistant to Schistosoma mansoni, to a highly susceptible strain (Cabo Frio, RJ, Brazil) of the same species, showed in the recipient snails resistance against the trematode, when a successful transplant occurred. The success of transplantation could be confirmed by a typical molecular marker of the Taim strain in haemocytes of the recipients (350 bp detected by PCR-RFLP). The recipient snails which did not present the donor marker in haemocytes (unsuccessful transplantation) were infected with the parasite. The use of an atoxic modelling clay for closing the hole in the transplantation site reduced significantly the mortality caused by bleeding after transplantation procedures.

Cost Effectiveness of Candida Polymerase Chain Reaction Detection and Empirical Antifungal Treatment among Patients with Suspected Fungal Peritonitis in the Intensive Care Unit.

PubMed

Pagès, Arnaud; Iriart, Xavier; Molinier, Laurent; Georges, Bernard; Berry, Antoine; Massip, Patrice; Juillard-Condat, Blandine

2017-12-01

Mortality from intra-abdominal candidiasis in intensive care units (ICUs) is high. It takes many days for peritoneal-fluid fungal culture to become positive, and the recommended empirical antifungal therapy involves excessive costs. Polymerase chain reaction (PCR) should produce results more rapidly than fungal culture. To perform a cost-effectiveness analysis of the combination of several diagnostic and therapeutic strategies to manage Candida peritonitis in non-neutropenic adult patients in ICUs. We constructed a decision tree model to evaluate the cost effectiveness. Cost and effectiveness were taken into account in a 1-year time horizon and from the French National Health Insurance perspective. Six strategies were compared: fluconazole or echinocandin as an empirical therapy, plus diagnosis by fungal culture or detection by PCR of all Candida species, or use of PCR to detect most fluconazole-resistant Candida species (i.e., Candida krusei and Candida glabrata). The use of fluconazole empirical treatment and PCR to detect all Candida species is more cost effective than using fluconazole empirical treatment without PCR (incremental cost-effectiveness ratio of €40,055/quality-adjusted life-year). Empirical treatment with echinocandin plus PCR to detect C. krusei and C. glabrata is the most effective strategy, but has an incremental cost-effectiveness ratio of €93,776/quality-adjusted life-year. If the cost of echinocandin decreases, then strategies involving PCR plus empirical echinocandin become more cost-effective. Detection by PCR of all Candida species and of most fluconazole-resistant Candida species could improve the cost-effectiveness of fluconazole and echinocandin given to non-neutropenic patients with suspected peritoneal candidiasis in ICUs. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

The known two types of transglutaminases regulate immune and stress responses in white shrimp, Litopenaeus vannamei.

PubMed

Chang, Chin-Chyuan; Chang, Hao-Che; Liu, Kuan-Fu; Cheng, Winton

2016-06-01

Transglutaminases (TGs) play critical roles in blood coagulation, immune responses, and other biochemical functions, which undergo post-translational remodeling such as acetylation, phosphorylation and fatty acylation. Two types of TG have been identified in white shrimp, Litopenaeus vannamei, and further investigation on their potential function was conducted by gene silencing in the present study. Total haemocyte count (THC), differential haemocyte count (DHC), phenoloxidase activity, respiratory bursts (release of superoxide anion), superoxide dismutase activity, transglutaminase (TG) activity, haemolymph clotting time, and phagocytic activity and clearance efficiency to the pathogen Vibrio alginolyticus were measured when shrimps were individually injected with diethyl pyrocarbonate-water (DEPC-H2O) or TG dsRNAs. In addition, haemolymph glucose and lactate, and haemocytes crustin, lysozyme, crustacean hyperglycemic hormone (CHH), transglutaminaseI (TGI), transglutaminaseII (TGII) and clotting protein (CP) mRNA expression were determined in the dsRNA injected shrimp under hypothermal stress. Results showed that TG activity, phagocytic activity and clearance efficiency were significantly decreased, but THC, hyaline cells (HCs) and haemolymph clotting time were significantly increased in the shrimp which received LvTGI dsRNA and LvTGI + LvTGII dsRNA after 3 days. However, respiratory burst per haemocyte was significantly decreased in only LvTGI + LvTGII silenced shrimp. In hypothermal stress studies, elevation of haemolymph glucose and lactate was observed in all treated groups, and were advanced in LvTGI and LvTGI + LvTGII silenced shrimp following exposure to 22 °C. LvCHH mRNA expression was significantly up-regulated, but crustin and lysozyme mRNA expressions were significantly down-regulated in LvTGI and LvTGI + LvTGII silenced shrimp; moreover, LvTGII was significantly increased, but LvTGI was significantly decreased in LvTGI silenced shrimp

The Candida Pathogenic Species Complex

PubMed Central

Turner, Siobhán A.; Butler, Geraldine

2014-01-01

Candida species are the most common causes of fungal infection. Approximately 90% of infections are caused by five species: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Three (C. albicans, C. tropicalis, and C. parapsilosis) belong to the CTG clade, in which the CTG codon is translated as serine and not leucine. C. albicans remains the most commonly isolated but is decreasing relative to the other species. The increasing incidence of C. glabrata is related to its reduced susceptibility to azole drugs. Genome analysis suggests that virulence in the CTG clade is associated with expansion of gene families, particularly of cell wall genes. Similar independent processes took place in the C. glabrata species group. Gene loss and expansion in an ancestor of C. glabrata may have resulted in preadaptations that enabled pathogenicity. PMID:25183855

Molecular Identification and Antifungal Susceptibility Pattern of Non-albicans Candida Species Isolated from Vulvovaginal Candidiasis

PubMed Central

Nejat, Ziba Abbasi; Farahyar, Shirin; Falahati, Mehraban; Khozani, Mahtab Ashrafi; Hosseini, Aga Fateme; Faiazy, Azamsadat; Ekhtiari, Masoome; Hashemi-Hafshenjani, Saeideh

2018-01-01

Background: Vulvovaginal candidiasis (VVC) is an important health problem caused by Candida spp. The aim of this study was molecular identification, phylogenetic analysis, and evaluation of antifungal susceptibility of non-albicans Candida isolates from VVC. Methods: Vaginal secretion samples were collected from 550 vaginitis patients at Sayyad Shirazi Medical and Educational Center of Gorgan (Golestan Province, Iran) from May to October 2015. Samples were analyzed using conventional mycological and molecular approaches. Clinical isolates were analyzed with specific PCR using CGL primers, and the internal transcribed spacer region and the D1-D2 domain of the large-subunit rRNA gene were amplified and sequenced. Susceptibility to amphotericin B, fluconazole, itraconazole, and clotrimazole was determined by the guidelines of the Clinical and Laboratory Standard Institute. Results: In total, 35 non-albicans Candida isolates were identified from VVC patients. The isolates included 27 strains of Candida glabrata (77.1%), 5 Candida krusei (Pichia kudriavzevii; 14.3%), 2 Candida kefyr (Kluyveromyces marxianus; 5.7%), and 1 Candida lusitaniae (Clavispora lusitaniae; 2.9%). The fungicides itraconazole and amphotericin B were effective against all species. One isolate of C. glabrata showed resistance to fluconazole and clotrimazole, and 26 isolates of C. glabrata indicated dose-dependent susceptibility to fluconazole. C. lusitaniae was susceptible in a dose-dependent manner to fluconazole and resistant to clotrimazole. Conclusions: Non-albicans Candida spp. are common agents of vulvovaginitis, and C. glabrata is the most common species in the tested patients. PMID:28688376

Drosophila blood cells and their role in immune responses.

PubMed

Vlisidou, Isabella; Wood, Will

2015-04-01

Drosophila melanogaster has been extensively used to study the humoral arm of innate immunity because of the developmental and functional parallels with mammalian innate immunity. However, the fly cellular response to infection is far less understood. Investigative work on Drosophila haemocytes, the immunosurveillance cells of the insect, has revealed that they fulfil roles similar to mammalian monocytes and macrophages. They respond to wound signals and orchestrate the coagulation response. In addition, they phagocytose and encapsulate invading pathogens, and clear up apoptotic bodies controlling inflammation. This review briefly describes the Drosophila haematopoietic system and discusses what is currently known about the contribution of haemocytes to the immune response upon infection and wounding, during all stages of development. © 2015 FEBS.

The modulation role of serotonin in Pacific oyster Crassostrea gigas in response to air exposure.

PubMed

Dong, Wenjing; Liu, Zhaoqun; Qiu, Limei; Wang, Weilin; Song, Xiaorui; Wang, Xiudan; Li, Yiqun; Xin, Lusheng; Wang, Lingling; Song, Linsheng

2017-03-01

Serotonin, also known as 5-hydroxytryptamine (5-HT), is a critical neurotransmitter in the neuroendocrine-immune regulatory network and involved in regulation of the stress response in vertebrates and invertebrates. In the present study, serotonin was found to be widely distributed in the tissues of Pacific oyster Crassostrea gigas, including haemolymph, gonad, visceral ganglion, mantle, gill, labial palps and hepatopancreas, and its concentration increased significantly in haemolymph and mantle after the oysters were exposed to air for 1 d. The apoptosis rate of haemocytes was significantly declined after the oysters received an injection of extra serotonin, while the activity of superoxide dismutase (SOD) in haemolymph increased significantly. After the stimulation of serotonin during air exposure, the apoptosis rate of oyster haemocytes and the concentration of H 2 O 2 in haemolymph were significantly decreased, while the SOD activity was significantly elevated. Furthermore, the survival rate of oysters from 4 th to 6 th d after injection of serotonin was higher than that of FSSW group and air exposure group. The results clearly indicated that serotonin could modulate apoptotic effect and redox during air exposure to protect oysters from stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predation of schistosomiasis vector snails by ostracoda (crustacea)

USGS Publications Warehouse

Sohn, I.G.; Kornicker, L.S.

1972-01-01

An ostracod species of Cypretta is an effective predator in laboratory experiments on 1- to 3-day-old Biomphalaria glabrata, a vector snail of the blood fluke that causes the tropical and subtropical disease schistosomiasis.

Use of Candida-specific chicken egg yolk antibodies to inhibit the adhering of Candida to denture base materials: prevention of denture stomatitis.

PubMed

Kamikawa, Yoshiaki; Fujisaki, Junichi; Nagayama, Tomohiro; Kawasaki, Kiyotsugu; Hirabayashi, Daisuke; Hamada, Tomofumi; Sakamoto, Ryoich; Mukai, Hiroshi; Sugihara, Kazumasa

2016-09-01

Polyclonal anti-Candida chicken egg yolk antibodies (anti-IgY) were used to investigate the prevention of adherence of Candida species to denture base material in vitro. Candida is a potential virulence factor that can cause systemic infection and even death in immunocompromised individuals. Because long-term antifungal treatment may lead to the emergence of drug-resistant strains, it is necessary to develop novel preventive measures and treatments for candidiasis. Three types of chicken egg yolk antibodies were used in this study: non-specific antibody (control IgY), Candida albicans-specific antibody (anti-C.a.IgY) and Candida glabrata-specific antibody (anti-C.g.IgY). A mixture of different dilutions of each antibody with a suspension of Candida species and denture base material was incubated for 3 h, and then the colony-forming units of Candida on the denture base material were counted. Compared with control IgY, anti-C.a.IgY and anti-C.g.IgY significantly inhibited the adherence of C. albicans, but anti-C.a.IgY tended to be more potent than anti-C.g.IgY. The adherence of C. glabrata was also inhibited significantly by anti-C.a.IgY and anti-C.g.IgY with almost equivalent potency, indicating that their actions against C. glabrata were comparable. This study revealed the inhibitory effects of anti-C.a.IgY and anti-C.g.IgY against the adherence of C. albicans and C. glabrata to denture base material. This finding indicates the possibility of a beneficial effect of IgYs for the prevention of denture stomatitis and candidiasis in clinical settings. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Branchial lesions associated with abundant apoptotic cells in oysters Ostrea edulis of Galicia (NW Spain).

PubMed

Mirella da Silva, P; Villalba, Antonio; Sunila, Inke

2006-06-12

An experiment to evaluate differences in growth, mortality and disease susceptibility among Ostrea edulis stocks was performed. Five families were produced from each of 4 oyster populations (Irish, Greek and 2 Galician). The spat were transferred to a raft in the Ria de Arousa (Galicia, Spain) for grow-out. Monthly samples of each family were histologically processed from 2001 to 2003. One of the pathological conditions discovered by this study was the occurrence of extensive branchial lesions characterized by haemocytic infiltration and loss of branchial architecture. Furthermore, abundant atypical cells occurred among the haemocytes in the lesions in the branchial connective and epithelial tissues, but rarely in the mantle. These cells were contracted in size with nuclei showing chromatin condensation and fragmentation. Some nuclear chromatin aggregated under the nuclear membranes into crescent shapes, whereas others were uniformly dense. Those characteristics suggested that the cells were apoptotic haemocytes, which was confirmed by transmission electron microscopy (TEM) and by a terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labelling (TUNEL) assay using the Apoptag Kit on paraffin sections. A low prevalence of gill lesions was detected in some, but not all, families of every origin peaking in July 2002 and April 2003. No etiologic agent was identified by either histology or TEM; thus, the cause of the abundance of apoptotic cells remains unclear.

Can ecological history influence immunomarker responses and antioxidant enzyme activities in bivalves that have been experimentally exposed to contaminants? A new subject for discussion in "eco-immunology" studies.

PubMed

Matozzo, Valerio; Giacomazzo, Matteo; Finos, Livio; Marin, Maria Gabriella; Bargelloni, Luca; Milan, Massimo

2013-07-01

Numerous studies have demonstrated that environmental parameters affect bivalve immunomarkers. In the present study, we tested the hypothesis that clams (Venerupis philippinarum) collected in sites with different environmental conditions respond differently to experimental contaminant exposure. Clams were collected at two sites within the Lagoon of Venice that are influenced differently by both anthropogenic impact and natural conditions: Marghera, which is characterised by relatively high contamination levels and restricted clam fishing, and Chioggia, which is inside a licensed clam culture area that is characterised by lower contamination levels. Total haemocyte count, haemocyte diameter and volume, lysozyme activity in both haemocyte lysate and cell-free haemolymph, superoxide dismutase and catalase activities in gills and digestive glands were measured at time 0 (clam sampling time), after 7 days of acclimation in the laboratory and after 1, 3 and 7 days of copper exposure. Interestingly, statistical analyses (three-way ANOVA and Canonical Correlation Analysis) revealed persistent differences in the biological responses of clams from the two sampling sites before and after copper exposure. Conversely, the influence of copper on cellular and biochemical parameters was negligible. Overall, the results obtained indicated that animals with a different ecological history respond differently to experimental contaminant exposure. In addition, this study suggested that immunomarkers and other biomarkers might be used to determine the origin of fishing products. Copyright © 2013 Elsevier Ltd. All rights reserved.

Histological and three dimensional organizations of lymphoid tubules in normal lymphoid organ of Penaeus monodon.

PubMed

Duangsuwan, Pornsawan; Phoungpetchara, Ittipon; Tinikul, Yotsawan; Poljaroen, Jaruwan; Wanichanon, Chaitip; Sobhon, Prasert

2008-04-01

The normal lymphoid organ of Penaeus monodon (which tested negative for WSSV and YHV) was composed of two parts: lymphoid tubules and interstitial spaces, which were permeated with haemal sinuses filled with large numbers of haemocytes. There were three permanent types of cells present in the wall of lymphoid tubules: endothelial, stromal and capsular cells. Haemocytes penetrated the endothelium of the lymphoid tubule's wall to reside among the fixed cells. The outermost layer of the lymphoid tubule was covered by a network of fibers embedded in a PAS-positive extracellular matrix, which corresponded to a basket-like network that covered all the lymphoid tubules as visualized by a scanning electron microscope (SEM). Argyrophilic reticular fibers surrounded haemal sinuses and lymphoid tubules. Together they formed the scaffold that supported the lymphoid tubule. Using vascular cast and SEM, the three dimensional structure of the subgastric artery that supplies each lobe of the lymphoid organ was reconstructed. This artery branched into highly convoluted and blind-ending terminal capillaries, each forming the lumen of a lymphoid tubule around which haemocytes and other cells aggregated to form a cuff-like wall. Stromal cells which form part of the tubular scaffold were immunostained for vimentin. Examination of the whole-mounted lymphoid organ, immunostained for vimentin, by confocal microscopy exhibited the highly branching and convoluted lymphoid tubules matching the pattern of the vascular cast observed in SEM.

Non-albicans Candida Vulvovaginitis: Treatment Experience at a Tertiary Care Vaginitis Center.

PubMed

Powell, Anna M; Gracely, Edward; Nyirjesy, Paul

2016-01-01

The aims of this study are to analyze a cohort of women with vulvovaginal symptoms and positive cultures for non-albicans Candida (NAC) to determine whether yeast was responsible for their symptoms and to evaluate the mycological effectiveness of various regimens. This observational study was performed from retrospective chart review of patients with positive NAC cultures between April 1, 2008, and January 31, 2011, at a tertiary care vaginitis center. Patient intake demographics were entered into a database. Follow-up visits were analyzed for data about patient treatments and outcomes. Patients were considered a clinical cure if their symptoms were significantly improved and mycologic cure (MC) if later yeast cultures were negative. If clinical symptoms improved at the same time as MC, the isolate was considered the proximate cause for the symptoms. One hundred eight patients meeting entry criteria were analyzed. Boric acid was effective at obtaining MC in 32 (78%) of 41 patients with C. glabrata, 3 of 3 patients with C. tropicalis, and 3 of 3 patients with C. lusitaniae. Fluconazole was effective as initial treatment for 3 (60%) of 5 patients with C. glabrata and 13 (81%) of 16 patients with C. parapsilosis. In 52.7% of C. glabrata, 66.7% of C. parapsilosis, and 57.1% of C. tropicalis cases, effective antifungal therapy led to symptom improvement. In a tertiary care vaginitis center, NAC, when isolated on culture, caused clinically significant infections in approximately half of symptomatic patients. A majority of infections can be effectively treated with boric acid or fluconazole regardless of the non-albicans Candida species.

Yeasts from skin colonization are able to cross the acellular dermal matrix.

PubMed

Jarros, Isabele Carrilho; Okuno, Érika; Costa, Maiara Ignacio; Veiga, Flávia Franco; de Souza Bonfim-Mendonça, Patricia; Negri, Melyssa Fernanda Norman; Svidzinski, Terezinha Inez Estivalet

2018-04-01

In recent decades, the prognosis for burn patients has improved considerably with the development of specialized care. The acellular dermal matrix (ADM) is a totally artificial acellular device that functions to control water loss, prevent penetration by bacteria and allow migration of endothelial cells and fibroblasts from patient tissues. However, little is known about its effectiveness against yeasts. The present study evaluated the capacity of colonization and migration of some human commensal yeasts. Three clinical isolates from skin scales, identified as Candida parapsilosis, Candida glabrata and Rhodotorula mucilaginosa, were used. Their ability to cross the ADM was evaluated. After three days, all isolates had crossed the ADM. C. parapsilosis showed the lowest growth, while R. mucilaginosa showed intermediate and C. glabrata the highest growth. In the plates incubated for seven days, the growth of C. parapsilosis and C. glabrata increased by 1 log over the third day. All isolates have the capacity to colonize and migrate through the matrix, increasing the potential risk to burn patients, who can develop severe and even fatal infections by invasive fungi. Copyright © 2018 Elsevier Ltd. All rights reserved.

Species identification and antifungal susceptibility testing of Candida bloodstream isolates from population-based surveillance studies in two U.S. cities from 2008 to 2011.

PubMed

Lockhart, Shawn R; Iqbal, Naureen; Cleveland, Angela A; Farley, Monica M; Harrison, Lee H; Bolden, Carol B; Baughman, Wendy; Stein, Betsy; Hollick, Rosemary; Park, Benjamin J; Chiller, Tom

2012-11-01

Between 2008 and 2011, population-based candidemia surveillance was conducted in Atlanta, GA, and Baltimore, MD. Surveillance had been previously performed in Atlanta in 1992 to 1993 and in Baltimore in 1998 to 2000, making this the first population-based candidemia surveillance conducted over multiple time points in the United States. From 2,675 identified cases of candidemia in the current surveillance, 2,329 Candida isolates were collected. Candida albicans no longer comprised the majority of isolates but remained the most frequently isolated species (38%), followed by Candida glabrata (29%), Candida parapsilosis (17%), and Candida tropicalis (10%). The species distribution has changed over time; in both Atlanta and Baltimore the proportion of C. albicans isolates decreased, and the proportion of C. glabrata isolates increased, while the proportion of C. parapsilosis isolates increased in Baltimore only. There were 98 multispecies episodes, with C. albicans and C. glabrata the most frequently encountered combination. The new species-specific CLSI Candida MIC breakpoints were applied to these data. With the exception of C. glabrata (11.9% resistant), resistance to fluconazole was very low (2.3% of isolates for C. albicans, 6.2% for C. tropicalis, and 4.1% for C. parapsilosis). There was no change in the proportion of fluconazole resistance between surveillance periods. Overall echinocandin resistance was low (1% of isolates) but was higher for C. glabrata isolates, ranging from 2.1% isolates resistant to caspofungin in Baltimore to 3.1% isolates resistant to anidulafungin in Atlanta. Given the increase at both sites and the higher echinocandin resistance, C. glabrata should be closely monitored in future surveillance.

Species Identification and Antifungal Susceptibility Testing of Candida Bloodstream Isolates from Population-Based Surveillance Studies in Two U.S. Cities from 2008 to 2011

PubMed Central

Iqbal, Naureen; Cleveland, Angela A.; Farley, Monica M.; Harrison, Lee H.; Bolden, Carol B.; Baughman, Wendy; Stein, Betsy; Hollick, Rosemary; Park, Benjamin J.; Chiller, Tom

2012-01-01

Between 2008 and 2011, population-based candidemia surveillance was conducted in Atlanta, GA, and Baltimore, MD. Surveillance had been previously performed in Atlanta in 1992 to 1993 and in Baltimore in 1998 to 2000, making this the first population-based candidemia surveillance conducted over multiple time points in the United States. From 2,675 identified cases of candidemia in the current surveillance, 2,329 Candida isolates were collected. Candida albicans no longer comprised the majority of isolates but remained the most frequently isolated species (38%), followed by Candida glabrata (29%), Candida parapsilosis (17%), and Candida tropicalis (10%). The species distribution has changed over time; in both Atlanta and Baltimore the proportion of C. albicans isolates decreased, and the proportion of C. glabrata isolates increased, while the proportion of C. parapsilosis isolates increased in Baltimore only. There were 98 multispecies episodes, with C. albicans and C. glabrata the most frequently encountered combination. The new species-specific CLSI Candida MIC breakpoints were applied to these data. With the exception of C. glabrata (11.9% resistant), resistance to fluconazole was very low (2.3% of isolates for C. albicans, 6.2% for C. tropicalis, and 4.1% for C. parapsilosis). There was no change in the proportion of fluconazole resistance between surveillance periods. Overall echinocandin resistance was low (1% of isolates) but was higher for C. glabrata isolates, ranging from 2.1% isolates resistant to caspofungin in Baltimore to 3.1% isolates resistant to anidulafungin in Atlanta. Given the increase at both sites and the higher echinocandin resistance, C. glabrata should be closely monitored in future surveillance. PMID:22875889

Towards New Antifolates Targeting Eukaryotic Opportunistic Infections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J.; Bolstad, D; Bolstad, E

2009-01-01

Trimethoprim, an antifolate commonly prescribed in combination with sulfamethoxazole, potently inhibits several prokaryotic species of dihydrofolate reductase (DHFR). However, several eukaryotic pathogenic organisms are resistant to trimethoprim, preventing its effective use as a therapeutic for those infections. We have been building a program to reengineer trimethoprim to more potently and selectively inhibit eukaryotic species of DHFR as a viable strategy for new drug discovery targeting several opportunistic pathogens. We have developed a series of compounds that exhibit potent and selective inhibition of DHFR from the parasitic protozoa Cryptosporidium and Toxoplasma as well as the fungus Candida glabrata. A comparison ofmore » the structures of DHFR from the fungal species Candida glabrata and Pneumocystis suggests that the compounds may also potently inhibit Pneumocystis DHFR.« less

Effect of Mobile Phone Radiation on Cardiovascular Development of Chick Embryo.

PubMed

Ye, W; Wang, F; Zhang, W; Fang, N; Zhao, W; Wang, J

2016-06-01

The biological effects on cardiovascular development of chicken embryos were examined after radiation exposure using mobile phone (900 MHz; specific absorption rate˜1.07 W/kg) intermittently 3 h per day during incubation. Samples were selected by morphological and histological methods. The results showed the rate of embryonic mortality and cardiac deformity increased significantly in exposed group (P < 0.05). No any histological pathological changes were observed on Day 5-7 (D5-D7) of incubation. A higher distribution of lipid droplets was unexpectedly present in myocardial tissue from the exposure groups on D10-D13. Soon afterwards, myofilament disruption, atrioventricular valve focal necrosis, mitochondria vacuolization and atrial natriuretic peptide (ANP) decrease appeared on D15-D21 of incubation. Comet assay data showed the haemocyte mean tail in the exposed group was significantly larger than that of the control (P < 0.01). The arterial vascular wall of exposed group was thicker (P < 0.05) than that of the control on D13, which was reversed to normal in later stages. Our findings suggest that long-term exposure of MPR may induce myocardium pathological changes, DNA damage and increased mortality; however, there was little effect on vascular development. © 2015 Blackwell Verlag GmbH.

Impact of ocean acidification on antimicrobial activity in gills of the blue mussel (Mytilus edulis).

PubMed

Hernroth, B; Baden, S; Tassidis, H; Hörnaeus, K; Guillemant, J; Bergström Lind, S; Bergquist, J

2016-08-01

Here, we aimed to investigate potential effects of ocean acidification on antimicrobial peptide (AMP) activity in the gills of Mytilus edulis, as gills are directly facing seawater and the changing pH (predicted to be reduced from ∼8.1 to ∼7.7 by 2100). The AMP activity of gill and haemocyte extracts was compared at pH 6.0, 7.7 and 8.1, with a radial diffusion assay against Escherichia coli. The activity of the gill extracts was not affected by pH, while it was significantly reduced with increasing pH in the haemocyte extracts. Gill extracts were also tested against different species of Vibrio (V. parahaemolyticus, V. tubiashii, V. splendidus, V. alginolyticus) at pH 7.7 and 8.1. The metabolic activity of the bacteria decreased by ∼65-90%, depending on species of bacteria, but was, as in the radial diffusion assay, not affected by pH. The results indicated that AMPs from gills are efficient in a broad pH-range. However, when mussels were pre-exposed for pH 7.7 for four month the gill extracts presented significantly lower inhibit of bacterial growth. A full in-depth proteome investigation of gill extracts, using LC-Orbitrap MS/MS technique, showed that among previously described AMPs from haemocytes of Mytilus, myticin A was found up-regulated in response to lipopolysaccharide, 3 h post injection. Sporadic occurrence of other immune related peptides/proteins also pointed to a rapid response (0.5-3 h p.i.). Altogether, our results indicate that the gills of blue mussels constitute an important first line defence adapted to act at the pH of seawater. The antimicrobial activity of the gills is however modulated when mussels are under the pressure of ocean acidification, which may give future advantages for invading pathogens. Copyright © 2016. Published by Elsevier Ltd.

Combinatorial stresses kill pathogenic Candida species

PubMed Central

Kaloriti, Despoina; Tillmann, Anna; Cook, Emily; Jacobsen, Mette; You, Tao; Lenardon, Megan; Ames, Lauren; Barahona, Mauricio; Chandrasekaran, Komelapriya; Coghill, George; Goodman, Daniel; Gow, Neil A. R.; Grebogi, Celso; Ho, Hsueh-Lui; Ingram, Piers; McDonagh, Andrew; De Moura, Alessandro P. S.; Pang, Wei; Puttnam, Melanie; Radmaneshfar, Elahe; Romano, Maria Carmen; Silk, Daniel; Stark, Jaroslav; Stumpf, Michael; Thiel, Marco; Thorne, Thomas; Usher, Jane; Yin, Zhikang; Haynes, Ken; Brown, Alistair J. P.

2012-01-01

Pathogenic microbes exist in dynamic niches and have evolved robust adaptive responses to promote survival in their hosts. The major fungal pathogens of humans, Candida albicans and Candida glabrata, are exposed to a range of environmental stresses in their hosts including osmotic, oxidative and nitrosative stresses. Significant efforts have been devoted to the characterization of the adaptive responses to each of these stresses. In the wild, cells are frequently exposed simultaneously to combinations of these stresses and yet the effects of such combinatorial stresses have not been explored. We have developed a common experimental platform to facilitate the comparison of combinatorial stress responses in C. glabrata and C. albicans. This platform is based on the growth of cells in buffered rich medium at 30°C, and was used to define relatively low, medium and high doses of osmotic (NaCl), oxidative (H 2O2) and nitrosative stresses (e.g., dipropylenetriamine (DPTA)-NONOate). The effects of combinatorial stresses were compared with the corresponding individual stresses under these growth conditions. We show for the first time that certain combinations of combinatorial stress are especially potent in terms of their ability to kill C. albicans and C. glabrata and/or inhibit their growth. This was the case for combinations of osmotic plus oxidative stress and for oxidative plus nitrosative stress. We predict that combinatorial stresses may be highly signif cant in host defences against these pathogenic yeasts. PMID:22463109

Sublethal effect of copper toxicity against histopathological changes in the spiny lobster, Panulirus homarus (Linnaeus, 1758).

PubMed

Maharajan, A; Rajalakshmi, S; Vijayakumaran, M; Kumarasamy, P

2012-02-01

The tissue damage induced by various organic pollutants in aquatic animals is well documented, but there is a dearth of information relating to the histological alterations induced by copper in the spiny lobster. In the present study, intermoult juveniles of the spiny lobster Panulirus homarus (average weight 150-200 g) were exposed to two sublethal concentrations of the copper (9.55 and 19.1 μg/l) for a period of 28 days. The muscle, hepatopancreas, midgut, gills, thoracic ganglion and heart of the lobsters were then dissected out and processed for light microscopic studies. Exposure to copper was found to result in several alterations in the histoarchitecture of the muscle, hepatopancreas, midgut, gills, thoracic ganglion and heart of P. homarus. The alterations included disruption and congestion of muscle bundle in muscle tissue; blackened haemocytes; distended lumen and F cell; necrosis of the tubules of the hepatopancreas; disarrangement of circular muscle of the midgut; accumulation of haemocytes in the haemocoelic space; swelling and fusion of lamellae; abnormal gill tips; hyperplastic, necrotic, and blackened secondary gill lamellae of the gills; damaged neurosecretory cell and sensory and motor fibre; necrotic of the thoracic ganglion; dispersedly arranged muscle bands; clumped satellite cells and nucleus of the heart. The results obtained suggest that the muscle, hepatopancreas, midgut, gills, thoracic ganglion and heart of lobsters exposed to copper were structurally altered. Such alterations could affect vital physiological functions, such as absorption, storage and secretion of the hepatopancreas, digestion of gut and respiration, osmotic and ionic regulations of the gills, which in turn could ultimately affect the survival and growth of P. homarus. Thus, all possible remedial measures should be adopted to prevent the occurrence of copper contamination in the aquatic environment.

Cytometric analysis, genetic manipulation and antibiotic selection of the snail embryonic cell line Bge from Biomphalaria glabrata, the intermediate host of Schistosoma mansoni.

PubMed

Rinaldi, Gabriel; Yan, Hongbin; Nacif-Pimenta, Rafael; Matchimakul, Pitchaya; Bridger, Joanna; Mann, Victoria H; Smout, Michael J; Brindley, Paul J; Knight, Matty

2015-07-01

The invertebrate cell line, Bge, from embryos of the snail Biomphalaria glabrata, remains to date the only established cell line from any species of the Phylum Mollusca. Since its establishment in 1976 by Eder Hansen, few studies have focused on profiling its cytometrics, growth characteristics or sensitivity to xenobiotics. Bge cells are reputed to be challenging to propagate and maintain. Therefore, even though this cell line is a noteworthy resource, it has not been studied widely. With growing interest in functional genomics, including genetic transformation, to elucidate molecular aspects of the snail intermediate hosts responsible for transmission of schistosomiasis, and aiming to enhance the convenience of maintenance of this molluscan cell line, we deployed the xCELLigene real time approach to study Bge cells. Doubling times for three isolates of Bge, termed CB, SL and UK, were longer than for mammalian cell lines - longer than 40 h in complete Bge medium supplemented with 7% fetal bovine serum at 25°C, ranging from ∼42 h to ∼157 h when 40,000 cells were seeded. To assess the potential of the cells for genetic transformation, antibiotic selection was explored. Bge cells were sensitive to the aminonucleoside antibiotic puromycin (from Streptomyces alboniger) from 5 μg/ml to 200 ng/ml, displaying a half maximal inhibitory concentration (IC50) of ∼1.91 μg/ml. Sensitivity to puromycin, and a relatively quick kill time (<48 h in 5 μg/ml) facilitated use of this antibiotic, together with the cognate resistance gene (puromycin N-acetyl-transferase) for selection of Bge cells transformed with the PAC gene (puroR). Bge cells transfected with a plasmid encoding puroR were partially rescued when cultured in the presence of 5 μg/ml of puromycin. These findings pave the way for the development of functional genomic tools applied to the host-parasite interaction during schistosomiasis and neglected tropical trematodiases at large. Copyright © 2015 Australian

Ocean acidification and host-pathogen interactions: blue mussels, Mytilus edulis, encountering Vibrio tubiashii.

PubMed

Asplund, Maria E; Baden, Susanne P; Russ, Sarah; Ellis, Robert P; Gong, Ningping; Hernroth, Bodil E

2014-04-01

Ocean acidification (OA) can shift the ecological balance between interacting organisms. In this study, we have used a model system to illustrate the interaction between a calcifying host organism, the blue mussel Mytilus edulis and a common bivalve bacterial pathogen, Vibrio tubiashii, with organisms being exposed to a level of acidification projected to occur by the end of the 21st century. OA exposures of the mussels were carried out in relative long-term (4 months) and short-term (4 days) experiments. We found no effect of OA on the culturability of V. tubiashii, in broth or in seawater. OA inhibited mussel shell growth and impaired crystalline shell structures but did not appear to affect mussel immune parameters (i.e haemocyte counts and phagocytotic capacity). Despite no evident impact on host immunity or growth and virulence of the pathogen, V. tubiashii was clearly more successful in infecting mussels exposed to long-term OA compared to those maintained under ambient conditions. Moreover, OA exposed V. tubiashii increased their viability when exposed to haemocytes of OA-treated mussel. Our findings suggest that even though host organisms may have the capacity to cope with periods of OA, these conditions may alter the outcome of host-pathogen interactions, favouring the success of the latter. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

A first insight into temperature stress-induced neuroendocrine and immunological changes in giant freshwater prawn, Macrobrachium rosenbergii.

PubMed

Chang, Chin-Chyuan; Jiang, Jia-Rong; Cheng, Winton

2015-11-01

Haemolymph norepinephrine (NE); total haemocyte count (THC); respiratory bursts (RBs); superoxide dismutase (SOD), phenoloxidase (PO), and phagocytic activity; and prophenoloxidase (proPO)-system-related genes (lipopolysaccharide- and β-1,3-glucan-binding protein: LGBP, proPO, peroxinectin: PE, and α2-macroglobulin: α2-M) in haemocytes of Macrobrachium rosenbergii were investigated after transferring them from 28 °C to 22 °C, 28 °C, and 34 °C respectively. The results revealed that haemolymph NE, hyaline cells (HCs), and PO activity per granulocyte increased from 30 to 120 min of exposure, and however, RBs and phagocytic activity significantly decreased from 30 to 120 min of exposure as well as granular cells (GCs), semigranular cells (SGCs), and SOD activity decreased from 60 to 120 min of exposure for the prawns subjected to temperature stress. The proPO-system-related gene expression markedly increased with 60-120 min of exposure for the prawns transferred from 28 °C to 22 °C and 34 °C, except α2M at 120 min. These results provide a first insight into the effects of temperature stress on haemolymph NE level and immune functions in prawns and suggest that temperature-stress-induced acute modulation in immunity is associated with the release of haemolymph NE in M. rosenbergii. Copyright © 2015 Elsevier Ltd. All rights reserved.

Echinocandin resistance among Candida isolates at an academic medical centre 2005-15: analysis of trends and outcomes.

PubMed

McCarty, Todd P; Lockhart, Shawn R; Moser, Stephen A; Whiddon, Jennifer; Zurko, Joanna; Pham, Cau D; Pappas, Peter G

2018-02-28

To identify the frequency of micafungin resistance among clinically significant isolates of Candida stored at our institution from 2005 to 2015. Chart review of patients with resistant isolates then informed the clinical setting and outcomes associated with these infections. Clinical Candida isolates had been stored at -80°C in Brucella broth with 20% glycerol from 2005. Isolates were tested using broth microdilution to determine micafungin MICs. All Candida glabrata isolates and all isolates demonstrating decreased susceptibility to micafungin were screened for FKS mutations using a Luminex assay. In total, 3876 Candida isolates were tested for micafungin resistance, including 832 C. glabrata isolates. Of those, 33 isolates from 31 patients were found to have either decreased susceptibility to micafungin and/or an FKS mutation. C. glabrata accounted for the majority of these isolates. While bloodstream infections were found to have a very high mortality rate, isolates from other sites were uncommonly associated with 30-day mortality. Overall resistance rates were very low. Echinocandin resistance in C. glabrata has been increasingly reported but rates at our institution remain very low. We hypothesize that a focus on antifungal stewardship may have led to these observations. Knowledge of local resistance patterns is key to appropriate empirical treatment strategies.

Comparison of In Vitro Susceptibility Characteristics of Candida Species from Cases of Invasive Candidiasis in Solid Organ and Stem Cell Transplant Recipients: Transplant-Associated Infections Surveillance Network (TRANSNET), 2001 to 2006▿

PubMed Central

Lockhart, Shawn R.; Wagner, Debra; Iqbal, Naureen; Pappas, Peter G.; Andes, David R.; Kauffman, Carol A.; Brumble, Lisa M.; Hadley, Susan; Walker, Randall; Ito, James I.; Baddley, John W.; Chiller, Tom; Park, Benjamin J.

2011-01-01

Invasive fungal infections (IFI) are a major cause of morbidity and mortality among both solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients. Candida is the most common cause of IFI in SOT recipients and the second most common cause of IFI in HSCT recipients. We determined susceptibilities to fluconazole, voriconazole, itraconazole, posaconazole, amphotericin B, and caspofungin for 383 invasive Candida sp. isolates from SOT and HSCT recipients enrolled in the Transplant-Associated Infection Surveillance Network and correlated these results to clinical data. Fluconazole resistance in C. albicans, C. tropicalis, and C. parapsilosis isolates was low (1%), but the high percentage of C. glabrata and C. krusei isolates within this group of patients increased the overall percentage of fluconazole resistance to 16%. Voriconazole resistance was 3% overall but was 8% among C. glabrata isolates. On multivariable analysis, among HSCT recipients fluconazole nonsusceptibility was independently associated with C. glabrata, non-Hodgkin's lymphoma, cytomegalovirus (CMV) antigenemia, diabetes active at the time of the IFI, and any prior amphotericin B use; among SOT recipients, fluconazole nonsusceptibility was independently associated with any fluconazole use in the 3 months prior to the IFI, C. glabrata, ganciclovir use in the 3 months prior to the IFI, diabetes acquired since the transplant, and gender. PMID:21562099

Assessing the health status of farmed mussels (Mytilus galloprovincialis) through histological, microbiological and biomarker analyses.

PubMed

Matozzo, Valerio; Ercolini, Carlo; Serracca, Laura; Battistini, Roberta; Rossini, Irene; Granato, Giulia; Quaglieri, Elisabetta; Perolo, Alberto; Finos, Livio; Arcangeli, Giuseppe; Bertotto, Daniela; Radaelli, Giuseppe; Chollet, Bruno; Arzul, Isabelle; Quaglio, Francesco

2018-03-01

The Gulf of La Spezia (northern Tyrrhenian Sea, Italy) is a commercially important area both as a shipping port and for mussel farming. Recently, there has been increased concern over environmental disturbances caused by anthropogenic activities such as ship traffic and dredging and the effects they have on the health of farmed mussels. This paper reports the results of microbiological and histological analyses, as well as of measurement of several biomarkers which were performed to assess the health status of mussels (Mytilus galloprovincialis) from four rearing sites in the Gulf of La Spezia. Mussels were collected between October 2015 and September 2016 and histological analyses (including gonadal maturation stage), as well as the presence of pathogenic bacteria (Vibrio splendidus clade, V. aestuarianus and V. harveyi), viruses (Herpes virus and ostreid Herpes virus 1) and protozoa (Marteilia spp., in the summer season only) were carried out on a monthly basis. Conversely, biomarker responses in haemocyte/haemolymph (total haemocyte count, haemocyte diameter and volume, lysozyme and lactate dehydrogenase activities in cell-free haemolymph, and micronuclei frequency) and in gills and digestive gland (cortisol-like steroids and lipid peroxidation levels), were evaluated bimonthly. Microbiological data indicated that mussels contain a reservoir of potentially pathogenic bacteria, viruses and protozoa that in certain environmental conditions may cause a weakening of the immune system of animals leading to mortality episodes. The percentage of parasites detected in the mussels was generally low (9.6% for Steinhausia mytilovum, that is 17 samples out of 177 examined females; 3.4% for Proctoeces maculatus; 0.9% for Mytilicola intestinalis and 2% for ciliated protozoa), while symbiont loads were higher (31% for Eugymnanthea inquilina and Urastoma cyprinae). Interestingly, a previously undescribed haplosporidian was detected in a single mussel sample (0.2%) and was

[Molecular epidemiology and antifungal susceptibility of Candida species isolated from urine samples of patients in intensive care unit].

PubMed

Yüksekkaya, Serife; Fındık, Duygu; Arslan, Uğur

2011-01-01

The aims of this study were to analyse the amphotericin B and fluconazole susceptibility and molecular epidemiology of Candida strains (Candida albicans, Candida tropicalis and Candida glabrata) isolated from the urine samples of patients hospitalized in the intensive care unit. Identification of the isolates was done according to microscopic morphology (chlamydospor, blastospor, pseudohyphae and true hyphae) on cornmeal agar, germ tube formation and carbohydrate assimilation patterns (API ID 32C bioMérieux, France). Antifungal susceptibilities of the isolates were determined by in vitro broth microdilution method recommended by Clinical and Laboratory Standards Institute (CLSI). To investigate the clonal relationship of the isolates, randomly amplified polymorphic DNA (RAPD) analysis was performed by using Cnd3 primer. Of the 56 Candida isolates minimum inhibitory concentration (MIC) ranges, MIC50 and MIC90 values for amphotericin B were 0.125-1 µg/ml, 0.125 and 0.5 µg/ml for C.albicans, 0.125-1 µg/ml, 0.25 and 1 µg/ml for C.tropicalis and 0.125-1 µg/ml, 0.25 and 1 µg/ml for C.glabrata, respectively. Fluconazole MIC ranges, MIC50 and MIC90 values were 0.25-4 µg/ml, 0.25 and 0.5 µg/ml for C.albicans, 0.25-16 µg/ml, 0.5 and 1 µg/ml for C.tropicalis and 0.5-64 µg/ml, 8 and 16 µg/ml for C.glabrata, respectively. For amphotericin B, none of the isolates had high MIC values (MIC > 1 µg/ml). While one of the C.glabrata isolates was resistant to fluconazole (MIC ≥ 64 µg/ml), one C.tropicalis and two C.glabrata isolates were dose-dependent susceptible (MIC: 16-32 µg/ml). The results of RAPD analysis indicated an exogenous spread from two clones for C.albicans, one clone for C.glabrata and one clone for C.tropicalis. This study underlines the importance of molecular epidemiological analysis of clinical samples together with hospital environmental samples in terms of Candida spp. To determine the exogenous origin for the related strains and to prevent

Dynamics of Mixed- Candida Species Biofilms in Response to Antifungals.

PubMed

Vipulanandan, G; Herrera, M; Wiederhold, N P; Li, X; Mintz, J; Wickes, B L; Kadosh, D

2018-01-01

Oral infections caused by Candida species, the most commonly isolated human fungal pathogen, are frequently associated with biofilms. Although Candida albicans is the predominant organism found in patients with oral thrush, a biofilm infection, there is an increasing incidence of oral colonization and infections caused by non- albicans Candida species, including C. glabrata, C. dubliniensis, and C. tropicalis, which are frequently more resistant to antifungal treatment. While single-species Candida biofilms have been well studied, considerably less is known about the dynamics of mixed- Candida species biofilms and how these dynamics are altered by antifungal treatment. To address these questions, we developed a quantitative polymerase chain reaction-based approach to determine the precise species composition of mixed- Candida species biofilms formed by clinical isolates and laboratory strains in the presence and absence of clinically relevant concentrations of 3 commonly used antifungals: fluconazole, caspofungin, and amphotericin B. In monospecies biofilms, fluconazole exposure favored growth of C. glabrata and C. tropicalis, while caspofungin generally favored significant growth of all species to a varying degree. Fluconazole was not effective against preformed mixed- Candida species biofilms while amphotericin B was potent. As a general trend, in mixed- Candida species biofilms, C. albicans lost dominance in the presence of antifungals. Interestingly, presence in mixed versus monospecies biofilms reduced susceptibility to amphotericin B for C. tropicalis and C. glabrata. Overall, our data suggest that antifungal treatment favors the growth of specific non- albicans Candida species in mixed- Candida species biofilms.

The effect of banana (Musa acuminata) peels hot-water extract on the immunity and resistance of giant freshwater prawn, Macrobrachium rosenbergii via dietary administration for a long term: Activity and gene transcription.

PubMed

Rattanavichai, Wutti; Chen, Ying-Nan; Chang, Chin-Chyuan; Cheng, Winton

2015-10-01

The non-specific immune parameters, disease resistance and immune genes expressions in Macrobrachium rosenbergii were evaluated at 120 days of post feeding the diets containing the extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). Results showed that prawns fed with a diet containing BPE at the level of 1.0, 3.0 and 6.0 g kg(-1) for 120 days had a significantly higher survival rate (30.0%, 40.0% and 56.7%, respectively) than those fed with the control diet after challenge with Lactococcus garvieae for 144 h, and the respective relative survival percentages were 22.2%, 33.3%, and 51.9%, respectively. Dietary BPE supplementation at 3.0 and/or 6.0 g kg(-1) for 120 days showed a significant increase total haemocyte count (THC), granular cell (GC), superoxide dismutase (SOD) activity, phenoloxidase (PO) activity, transglutaminase (TG) activity, and phagocytic activity and clearance efficiency to L. garvieae infection, and meanwhile, the significant decrease in haemolymph clotting times and respiratory bursts (RBs) per haemocyte of prawns were revealed. Furthermore, the mRNA expressions of prophenoloxidase (proPO), lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PE), transglutaminase (TG), and crustin (CT) were significantly increased. We therefore recommend that BPE can be used as an immunomodulator for prawns through dietary administration at 6.0 g kg(-1) for a long term (over 120 days) to modify immune responses and genes expression following the enhanced resistance against pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dataset on usnic acid from Cladonia substellata Vainio (Lichen) schistosomiasis mansoni's vector control and environmental toxicity.

PubMed

Andrade de Araújo, Hallysson Douglas; Dos Santos Silva, Luanna Ribeiro; de Siqueira, Williams Nascimento; Martins da Fonseca, Caíque Silveira; da Silva, Nicácio Henrique; de Albuquerque Melo, Ana Maria Mendonça; Barroso Martins, Mônica Cristina; de Menezes Lima, Vera Lúcia

2018-04-01

This text presents complementary data corresponding to schistosomiasis mansoni's vector control and enviromental toxicity using usnic acid. These informations support our research article "Toxicity of Usnic Acid from Cladonia substellata (Lichen) to embryos and adults of Biomphalaria glabrata " by Araújo et al. [1], and focuses on the analysis of the detailed data regarding the different concentrations of Usnic Acid and their efficiency to B. glabrata mortality and non-viability, as also to environmental toxicity, evaluated by A. salina mortality.

Cryptococcus neoformans Capsular Enlargement and Cellular Gigantism during Galleria mellonella Infection

PubMed Central

García-Rodas, Rocío; Casadevall, Arturo; Rodríguez-Tudela, Juan Luís; Cuenca-Estrella, Manuel; Zaragoza, Oscar

2011-01-01

We have studied infection of Cryptococcus neoformans in the non-vertebrate host Galleria mellonella with particular interest in the morphological response of the yeast. Inoculation of C. neoformans in caterpillars induced a capsule-independent increase in haemocyte density 2 h after infection. C. neoformans manifested a significant increase in capsule size after inoculation into the caterpillar. The magnitude of capsule increase depended on the temperature, being more pronounced at 37°C than at 30°C, which correlated with an increased virulence of the fungus and reduced phagocytosis at 37°C. Capsule enlargement impaired phagocytosis by haemocytes. Incubation of the yeast in G. mellonella extracts also resulted in capsule enlargement, with the polar lipidic fraction having a prominent role in this effect. During infection, the capsule decreased in permeability. A low proportion of the cells (<5%) recovered from caterpillars measured more than 30 µm and were considered giant cells. Giant cells recovered from mice were able to kill the caterpillars in a manner similar to regular cells obtained from in vivo or grown in vitro, establishing their capacity to cause disease. Our results indicate that the morphological transitions exhibited by C. neoformans in mammals also occur in a non-vertebrate host system. The similarities in morphological transitions observed in different animal hosts and in their triggers are consistent with the hypothesis that the cell body and capsular responses represent an adaptation of environmental survival strategies to pathogenesis. PMID:21915338

CgA1AR-1 acts as an alpha-1 adrenergic receptor in oyster Crassostrea gigas mediating both cellular and humoral immune response.

PubMed

Liu, Zhaoqun; Zhou, Zhi; Wang, Lingling; Qiu, Limei; Zhang, Huan; Wang, Hao; Song, Linsheng

2016-11-01

We have now cloned an alpha-1 adrenergic receptor (A1AR) from the cDNA library of oyster Crassostrea gigas, designating as CgA1AR-1. The full length of CgA1AR-1 was 1149 bp and it encodes a protein of 382 amino acids containing a 7 transmembrane domain, whose putative topology was similar to the A1ARs in higher organisms and shared similarity of 19% with mammalian A1ARs according to the phylogenic analysis. After cell transfection of CgA1AR-1 into HEK293T cells and the incubation with its specific agonist norepinephrine (NE), the concentration of second messenger Ca 2+ increased significantly (p < 0.05). But, this increasing of Ca 2+ could be inhibited by adding A1AR antagonist DOX. Tissue distribution assays using qRT-PCR suggested that CgA1AR-1 mRNA was ubiquitously expressed in all the major tissues of oyster. LPS stimulation could induce the up-regulation of CgA1AR-1 mRNA in haemocytes from 12 h to 24 h post stimulation. Moreover, the blocking of CgA1AR-1 by DOX before LPS stimulation affected the mRNA expression of oyster TNF (CGI_10005109 and CGI_10006440) in haemocytes, resulting in the rise of haemocyte phagocytic rate and apoptosis index. In addition to cellular immunity, CgA1AR-1 was also involved in humoral immunity of oyster. Inhibition of CgA1AR-1 with DOX could repress the up-regulation of LZY and SOD activities caused by LPS stimulation. These results suggested that CgA1AR-1 acted as an α-1 adrenergic receptor in cetacholaminergic neuroendocrine-immune network mediating both cellular and humoral immune response. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biomarker responses and PAH uptake in Mya truncata following exposure to oil-contaminated sediment in an Arctic fjord (Svalbard).

PubMed

Camus, L; Birkely, S R; Jones, M B; Børseth, J F; Grøsvik, B E; Gulliksen, B; Lønne, O J; Regoli, F; Depledge, M H

2003-06-01

Expanding industrial activity (notably oil and gas exploration) in the Arctic requires assessment of the potential impact of chemicals on marine organisms living in seawater at low temperature. The bivalve Mya truncata is common in Svalbard fjord (Norway) where it experiences low temperature throughout the year. To measure the impact of polycyclic aromatic hydrocarbons (PAH) on M. truncata, the responses of three biomarkers [total oxyradical scavenging capacity-assay (TOSC), plasma membrane stability of haemocytes and respiration rates] were investigated from bivalves exposed to sediment contaminated with a PAH mixture (crude oil). After two weeks of exposure to the contaminated sediment, TOSC showed no change. The high TOSC value (4010+/-1339 unit mg(-1) protein) of Mya truncata (control group) is thought to protect biomolecules with a low turnover rate efficiently in a low food availability environment. In the exposed bivalves, the haemocyte cellular membranes were significantly destabilised compared with controls (P<0.05). Respiration rate of control and PAH-exposed individuals (0.055+/-0.020 mg O(2) dw(-1) h(-1)) was similar and relatively low as is typical for polar bivalves, reflecting a strategy to minimise energy expenditure to cope with 9 months of starvation. Bioaccumulation of PAH by M. truncata was also low, due probably to a combination of low metabolic rate and reduced solubility of the oil compounds at low temperature. Data indicated an uptake of mainly low molecular weight compounds (two and three ring molecules). A good correlation of logBAF(lipid) (bioaccumulation factor) and logK(ow) (octanol/water partitioning coefficient) was shown (r(2)=0.87). Tissue sensitivity and/or functional differences (digestive gland vs. haemocytes), PAH uptake route (dietary vs. gills), the low metabolic rate of M. truncata and the low environmental temperature (reducing the bioavailability of PAH) are factors that help explain these findings.

Leucopenia associated with abalone viral ganglioneuritis.

PubMed

Hooper, C; Slocombe, R; Day, R; Crawford, S

2012-01-01

To compare microscopic lesion severity with circulating total haemocyte counts (THC) in abalone affected by abalone viral ganglioneuritis (AVG). A herpes-like virus led to severe mortality in a number of Australian abalone farms in 2006. The infection was associated with severe necrotising ganglioneuritis. The microscopic lesions were well demarcated, affecting the neural tissue almost exclusively and were characterised by necrosis and increased cellularity in affected ganglia and nerves. On two farms, the presence or absence of typical AVG pathology was compared with THC. Those abalone with microscopic lesions of AVG had significantly lower haemocyte counts. The mean THC in abalone with no evidence of AVG from both farms was 4.6 × 10(6)/mL (±0.3 SE). The THC in AVG-affected abalone in farm 1 was 2.8 × 10(6)/mL (±0.5 SE) and farm 2 was 0.98 × 10(6)/mL (±0.4 SE). Severe AVG is associated with leucopenia in affected abalone. © 2012 The Authors. Australian Veterinary Journal © 2012 Australian Veterinary Association.

Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), Inhibits Candida Biofilms: A Metabolomic Approach.

PubMed

Bhardwaj, Anuja; Gupta, Payal; Kumar, Navin; Mishra, Jigni; Kumar, Ajai; Rakhee, Rajput; Misra, Kshipra

2017-01-01

This article presents a comparative gas chromatography (GC)-mass spectrometry (MS)-based metabolomic analysis of mycelia and fruiting bodies of the medicinal mushroom Ganoderma lucidum. Three aqueous extracts-mycelia, fruiting bodies, and a mixture of them-and their sequential fractions (methanolic and ethyl acetate), prepared using an accelerated solvent extractor, were characterized by GC-MS to determine volatile organic compounds and by high-performance thin-layer chromatography to quantify ascorbic acid, a potent antioxidant. In addition, these extracts and fractions were assessed against Candida albicans and C. glabrata biofilms via the XTT reduction assay, and their antioxidant potential was evaluated. Application of chemometrics (hierarchical cluster analysis and principal component analysis) to GC data revealed variability in volatile organic compound profiles among G. lucidum extracts and fractions. The mycelial aqueous extract demonstrated higher anti-Candida activity and ascorbic acid content among all the extracts and fractions. Thus, this study illustrates the preventive effect of G. lucidum against C. albicans and C. glabrata biofilms along with its nutritional value.

An Effective Big Data Supervised Imbalanced Classification Approach for Ortholog Detection in Related Yeast Species.

PubMed

Galpert, Deborah; Del Río, Sara; Herrera, Francisco; Ancede-Gallardo, Evys; Antunes, Agostinho; Agüero-Chapin, Guillermin

2015-01-01

Orthology detection requires more effective scaling algorithms. In this paper, a set of gene pair features based on similarity measures (alignment scores, sequence length, gene membership to conserved regions, and physicochemical profiles) are combined in a supervised pairwise ortholog detection approach to improve effectiveness considering low ortholog ratios in relation to the possible pairwise comparison between two genomes. In this scenario, big data supervised classifiers managing imbalance between ortholog and nonortholog pair classes allow for an effective scaling solution built from two genomes and extended to other genome pairs. The supervised approach was compared with RBH, RSD, and OMA algorithms by using the following yeast genome pairs: Saccharomyces cerevisiae-Kluyveromyces lactis, Saccharomyces cerevisiae-Candida glabrata, and Saccharomyces cerevisiae-Schizosaccharomyces pombe as benchmark datasets. Because of the large amount of imbalanced data, the building and testing of the supervised model were only possible by using big data supervised classifiers managing imbalance. Evaluation metrics taking low ortholog ratios into account were applied. From the effectiveness perspective, MapReduce Random Oversampling combined with Spark SVM outperformed RBH, RSD, and OMA, probably because of the consideration of gene pair features beyond alignment similarities combined with the advances in big data supervised classification.

Effect of Meloidogyne arenaria and Mulch Type on Okra in Microplot Experiments.

PubMed

Ritzinger, C H; McSorley, R; Gallaher, R N

1998-12-01

The effects of perennial peanut (Arachis glabrata) hay, an aged yard-waste compost (mainly woodchips), and a control treatment without amendment were determined on two population levels of root-knot (Melaidogyne arenaria) nematode over three consecutive years in field microplots. Okra (Hibiscus esculentus, susceptible to the root-knot nematode) and a rye (Secale cereale) cover crop (poor nematode host) were used in the summer and winter seasons, respectively. The organic amendment treatments affected plant growth parameters. In the first year, okra yields were greatest in peanut-amended plots. Yield differences with amendment treatment diminished in the second and third years. Okra plant height, total fruit weight, and fruit number were greater with the lower population level of the root-knot nematode. Residual levels of nutrients in soil were greater where root-knot nematode levels and damage were higher and plant growth was poor. Nutrient levels affected the growth of a subsequent rye cover crop.

Presumptive identification of Candida species other than C. albicans, C. krusei, and C. tropicalis with the chromogenic medium CHROMagar Candida

PubMed Central

Hospenthal, Duane R; Beckius, Miriam L; Floyd, Karon L; Horvath, Lynn L; Murray, Clinton K

2006-01-01

Background CHROMagar Candida (CaC) is increasingly being reported as a medium used to differentiate Candida albicans from non-albicans Candida (NAC) species. Rapid identification of NAC can assist the clinician in selecting appropriate antifungal therapy. CaC is a differential chromogenic medium designed to identify C. albicans, C. krusei, and C. tropicalis based on colony color and morphology. Some reports have proposed that CaC can also reliably identify C. dubliniensis and C. glabrata. Methods We evaluated the usefulness of CaC in the identification of C. dubliniensis, C. famata, C. firmetaria, C. glabrata, C. guilliermondii, C. inconspicua, C. kefyr, C. lipolytica, C. lusitaniae, C. norvegensis, C. parapsilosis, and C. rugosa. Results Most NAC produced colonies that were shades of pink, lavender, or ivory. Several isolates of C. firmetaria and all C. inconspicua produced colonies difficult to differentiate from C. krusei. Most C. rugosa isolates produced unique colonies with morphology like C. krusei except in a light blue-green color. C. glabrata isolates produced small dark violet colonies that could be differentiated from the pink and lavender colors produced by other species. All seventeen isolates of C. dubliniensis produced green colonies similar to those produced by C. albicans. Conclusion C. glabrata and C. rugosa appear distinguishable from other species using CaC. Some NAC, including C. firmetaria and C. inconspicua, could be confused with C. krusei using this medium. PMID:16390552

Multi-drug resistant oral Candida species isolated from HIV-positive patients in South Africa and Cameroon.

PubMed

Dos Santos Abrantes, Pedro Miguel; McArthur, Carole P; Africa, Charlene Wilma Joyce

2014-06-01

Candida species are a common cause of infection in immune-compromised HIV-positive individuals, who are usually treated with the antifungal drug, fluconazole, in public hospitals in Africa. However, information about the prevalence of drug resistance to fluconazole and other antifungal agents on Candida species is very limited. This study examined 128 Candida isolates from South Africa and 126 Cameroonian Candida isolates for determination of species prevalence and antifungal drug susceptibility. The isolates were characterized by growth on chromogenic and selective media and by their susceptibility to 9 antifungal drugs tested using the TREK™ YeastOne9 drug panel (Thermo Scientific, USA). Eighty-three percent (82.8%) of South African isolates were Candida albicans (106 isolates), 9.4% were Candida glabrata (12 isolates), and 7.8% were Candida dubliniensis (10 isolates). Of the Cameroonian isolates, 73.02% were C. albicans (92 isolates); 19.05% C. glabrata (24 isolates); 3.2% Candida tropicalis (4 isolates); 2.4% Candida krusei (3 isolates); 1.59% either Candida kefyr, Candida parapsilopsis, or Candida lusitaneae (2 isolates); and 0.79% C. dubliniensis (1 isolate). Widespread C. albicans resistance to azoles was detected phenotypically in both populations. Differences in drug resistance were seen within C. glabrata found in both populations. Echinocandin drugs were more effective on isolates obtained from the Cameroon than in South Africa. A multiple-drug resistant C. dubliniensis strain isolated from the South African samples was inhibited only by 5-flucytosine in vitro on the YO9 panel. Drug resistance among oral Candida species is common among African HIV patients in these 2 countries. Regional surveillance of Candida species drug susceptibility should be undertaken to ensure effective treatment for HIV-positive patients. Copyright © 2014 Elsevier Inc. All rights reserved.

Antifungal susceptibility patterns of colonized Candida species isolates from immunocompromised pediatric patients in five university hospitals.

PubMed

Badiee, Parisa; Choopanizadeh, Maral; Moghadam, Abdolkarim Ghadimi; Nasab, Ali Hossaini; Jafarian, Hadis; Shamsizadeh, Ahmad; Soltani, Jafar

2017-12-01

Colonization of Candida species is common in pediatric patients admitted to hematology-oncology wards. The aim of this study was to identify colonized Candida species and their susceptibility patterns in hematologic pediatric patients. Samples were collected from mouth, nose, urine and stool of the patients admitted to five university hospitals and cultured on sabouraud dextrose agar. The isolates were identified by API 20 C AUX system and their susceptibility patterns were evaluated by CLSI M27-A3 and S4. From 650 patients, 320 (49.2%) were colonized with 387 Candida species. Candida albicans was the most prevalent isolated species, followed by Candida glabrata, Candida tropicalis, Candida famata, Candida kefyr and Candida kuresi . The epidemiological cut off value (ECV) for all Candida species to amphotericin B was ≤0.25 μg except C. krusei (4 μg). The resistance rate to fluconazole in this study in C. albicans was 4.9% with ECV 8 μg/ml, followed by C. tropicalis 8.8% with ECV 0.5 μg/ml. Voriconazole and posaconazole were effective antifungal agents for all Candida isolates. The ECV of C. albicans, Candida parapsilosis, C. tropicalis, C. glabrata and C. krusei for itraconazole were 0.5, 0.25, 0.5, 1 and 2 μg, respectively. The resistant and intermediate rates of Candida species to caspofungin in this study were 2.9%, 5.9%, 18.8%, 47.9%, 0.0% and 16.7% in C. tropicalis, C. glabrata and C. parapsilosis respectively. C. albicans was the most prevalent species in pediatric colonized patients. New azole agents like voriconazole and posaconazole are effective against non-albicans Candida species. Increase in intermediate species is alarming to future emerging resistant species.

[Development of cysticercoid larva of Hymenolepis nana var. fraterna in Tenebrio molitor and Leucophaea maderae haemoceles (author's transl)].

PubMed

Pesson, B; Leger, N; Bouchet, P

1978-01-01

When embryos of Hymenolepis nana var. fraterna are injected abdominally, they are able to reach the cysticercoid stage in the haemocele of Leucophaea maderae which naturally resist to infection by ingestion of the eggs. The haemocytic defence reaction of the cockroach and the structure of the surface of larvae are examined and compared with development in a natural host Tenebrio molitor.

Effect of starvation and refeeding on the hepatopancreas of whiteleg shrimp Penaeus vannamei (Boone) using computer-assisted image analysis.

PubMed

Cervellione, F; McGurk, C; Berger Eriksen, T; Van den Broeck, W

2017-11-01

Under normal farming conditions, shrimp can experience starvation periods attributable to disease outbreaks or adverse environmental conditions. Starvation leads to significant morphological changes in the hepatopancreas (HP), being the main organ for absorption and storage of nutrients. In the literature, limited research has described the effect on the HP of periods of starvation followed by refeeding and none in whiteleg shrimp (Penaeus vannamei) using computer-assisted image analysis (CAIA). This study describes the effect of starvation and starvation followed by refeeding on the HP of whiteleg shrimp using CAIA. Visiopharm ® software was used to quantify the following morphological parameters, measured as ratio to the total tissue area (TLA): total lumen area (TLA:TTA), haemocytic infiltration area in the intertubular spaces (HIA:TTA), B-cell vacuole area (VBA:TTA), lipid droplet area within R cells (LDA:TTA) and F-cell area (FCA:TTA). Significant changes were measured for HIA:TTA and LDA:TTA during starvation (increase in HIA:TTA associated with decrease in LDA:TTA) and starvation followed by refeeding (decrease in HIA:TTA associated with increase in LDA:TTA). In the future, HIA:TTA and LDA:TTA have the potential to be used in a pre-emptive manner to monitor the health of the HP, facilitate early diagnosis of diseases and study the pathophysiology of the organ. © 2017 John Wiley & Sons Ltd.

Prevalence of Candida bracarensis and Candida nivariensis in a Spanish collection of yeasts: comparison of results from a reference centre and from a population-based surveillance study of candidemia.

PubMed

Cuenca-Estrella, M; Gomez-Lopez, A; Isla, G; Rodriguez, D; Almirante, B; Pahissa, A; Rodriguez-Tudela, J L

2011-07-01

Two new species related to Candida glabrata, i.e., Candida nivariensis and Candida bracarensis, have been proposed. The occurrence of these species among isolates collected in a Spanish mycology reference laboratory in 2008-2009 was reviewed. In addition, strains recovered as part of an active population-based surveillance of candidemia conducted in Barcelona between 2002 and 2003 were also analyzed. Among 143 clinical isolates received in 2008-2009, three (2%) were identified as C. bracarensis and none as C. nivariensis through sequencing of their ribosomal DNA. Of the 31 strains initially identified as C. glabrata in the 2002-2003 population-based study (0.38 cases/100,000 population), none were found to belong to these related new species. Results from in vitro susceptibility studies of C. bracarensis isolates were comparable to those found with C. glabrata. Since new and cryptic species have been described, periodic surveillance including the use of molecular identification methods seems to be necessary in order to determine their frequency, geographical distribution and susceptibility profile.

[Prevalence of vaginal candidiasis in pregnant women. Identification of yeasts and susceptibility to antifungal agents].

PubMed

García Heredia, M; García, S D; Copolillo, E F; Cora Eliseth, M; Barata, A D; Vay, C A; de Torres, R A; Tiraboschi, N; Famiglietti, A M R

2006-01-01

Pregnant women are more susceptible to both vaginal colonization and infection by yeast. Our objectives were to determine the prevalence in pregnant women of yeasts isolated from vaginal exudates and their susceptibility to current antifungal drugs. A total of 493 patients was studied between December 1998 and February 2000. The prevalence of Candida spp. was 28% (Candida albicans 90.4%; Candida glabrata 6.3%; Candida parapsilosis 1.1%, Candida kefyr 1.1 %; unidentified species 1.1 %). The diffusion test in Shadomy agar was employed to determine the susceptibility to fluconazole, ketoconazole, itraconazole and nistatine. All C. albicans, C. kefyr and C. parapsilosis isolates were susceptible in vitro to the antifungal agents tested, while 1 in 6 C. glabrata isolates showed resistance to azole drugs; all strains were susceptible to nistatine. In pregnant women, C. albicans was the yeast most frequently isolated from vaginal exudates; it continues to be highly susceptible to antifungal drugs. Azole resistance was detected only among C. glabrata isolates. Identification to the species level is recommended, specially in cases of treatment failure and recurrent or chronic infection.

Endogenous growth factor stimulation of hemocyte proliferation induces resistance to Schistosoma mansoni challenge in the snail host.

PubMed

Pila, Emmanuel A; Gordy, Michelle A; Phillips, Valerie K; Kabore, Alethe L; Rudko, Sydney P; Hanington, Patrick C

2016-05-10

Digenean trematodes are a large, complex group of parasitic flatworms that infect an incredible diversity of organisms, including humans. Larval development of most digeneans takes place within a snail (Gastropoda). Compatibility between snails and digeneans is often very specific, such that suitable snail hosts define the geographical ranges of diseases caused by these worms. The immune cells (hemocytes) of a snail are sentinels that act as a crucial barrier to infection by larval digeneans. Hemocytes coordinate a robust and specific immunological response, participating directly in parasite killing by encapsulating and clearing the infection. Hemocyte proliferation and differentiation are influenced by unknown digenean-specific exogenous factors. However, we know nothing about the endogenous control of hemocyte development in any gastropod model. Here, we identify and functionally characterize a progranulin [Biomphalaria glabrata granulin (BgGRN)] from the snail B. glabrata, a natural host for the human blood fluke Schistosoma mansoni Granulins are growth factors that drive proliferation of immune cells in organisms, spanning the animal kingdom. We demonstrate that BgGRN induces proliferation of B. glabrata hemocytes, and specifically drives the production of an adherent hemocyte subset that participates centrally in the anti-digenean defense response. Additionally, we demonstrate that susceptible B. glabrata snails can be made resistant to infection with S. mansoni by first inducing hemocyte proliferation with BgGRN. This marks the functional characterization of an endogenous growth factor of a gastropod mollusc, and provides direct evidence of gain of resistance in a snail-digenean infection model using a defined factor to induce snail resistance to infection.

Immune response and parasitic infestation on Pacific white shrimp (Lithopenaeus vannamei) in immuno-probio circulation system (SI-PBR) in ponds

NASA Astrophysics Data System (ADS)

Mahasri, G.; Sari, P. D. W.; Prayogo

2018-04-01

The main causes of death of pacific white shrimp in aquaculture are diseases. One effort to control deseases by improving the defense ability of shrimp body against disesases and optimizing water quality during farming through the application of a new aquaculture technology called Immuno-Probiocirculation System (SI-PBR). This research aimed to analyze immune response on Total Haemocyte Count (THC) and Differential Haemocyte Count (DHC), parasitic infestation on pacific white shrimp in many ages, survival rate of pacific white shrimp during farming period for 90 days in SI-PBR. The results of this research showed that the lowest parasitic infestation (Zoothamnium penaei) is 12.46 % that happened on 90-days-old shrimp in SI-PBR pond, while the highest infestasion is on the shrimp not given SI-PBR, reaching 54.65 %. In addition, the immune response (THC and DHC) also increased. The highest survival rate discovered in 90 days shrimp farming is 80% using SI-PBR. This is higher than the pond without SI-PBR, which is 22 %. Therefore, SI-PBR in shrimp farming in tradisional ponds is able to increase immune response, survival rate, and is also able to decrease parasitic infestation during 90 days of farming.

Physical stress primes the immune response of Galleria mellonella larvae to infection by Candida albicans.

PubMed

Mowlds, Peter; Barron, Aoife; Kavanagh, Kevin

2008-05-01

Larvae of the greater wax moth (Galleria mellonella) that had been subjected to physical stress by shaking in cupped hands for 2 min showed reduced susceptibility to infection by Candida albicans when infected 24 h after the stress event. Physically stressed larvae demonstrated an increase in haemocyte density and elevated mRNA levels of galiomicin and an inducible metalloproteinase inhibitor (IMPI) but not transferrin or gallerimycin. In contrast, previous work has demonstrated that microbial priming of larvae resulted in the induction of all four genes. Examination of the expression of proteins in the insect haemolymph using 2D electrophoresis and MALDI TOF analysis revealed an increase in the intensity of a number of peptides showing some similarities with proteins associated with the insect immune response to infection. This study demonstrates that non-lethal physical stress primes the immune response of G. mellonella and this is mediated by elevated haemocyte numbers, increased mRNA levels of genes coding for two antimicrobial peptides and the appearance of novel peptides in the haemolymph. This work demonstrates that physical priming increases the insect immune response but the mechanism of this priming is different to that induced by low level exposure to microbial pathogens.

CHROMagar Candida Medium for Direct Susceptibility Testing of Yeast from Blood Cultures

PubMed Central

Tan, Grace L.; Peterson, Ellena M.

2005-01-01

An evaluation was performed on 95 blood cultures positive for Candida spp. to determine the correlation of direct susceptibility testing of fluconazole versus both standardized disk diffusion and MIC methods. For direct testing, an aliquot taken from BD BACTEC Plus and/or BD BACTEC Lytic/10 bottles (Becton Dickinson [BD], Sparks, MD) positive by gram stain for yeast was subcultured to CHROMagar Candida (BD), and a 25-μg fluconazole disk (BD) was placed on the plate. The area of growth inhibition surrounding the disk was measured at 24 and 48 h. In addition, a subculture of the isolate was tested by a microdilution MIC using YeastOne (TREK Diagnostics Systems Inc., OH) and disk diffusion (NCCLS M44-A) using a standardized inoculum plated onto CHROMagar Candida as well as Mueller-Hinton agar to which 2% glucose and 0.5 μg/ml methylene blue dye was added (MH-GMB). The categorical interpretation derived from the MIC was used as the reference to which the disk diffusion results were compared. There were a total of 41 Candida albicans, 23 Candida glabrata, 20 Candida parapsilosis, 9 Candida tropicalis, and 1 each of Candida krusei and Candida lusitaniae tested. At 24 h there was full agreement among the methods for all C. albicans, C. tropicalis, C. lusitaniae, and C. krusei isolates. For the C. parapsilosis isolates at 24 h there was one very major discrepancy using the direct CHROMagar and one major error with the standardized MH-GMB. The majority of the errors were seen at 24 h with the C. glabrata isolates. Of the 23 C. glabrata isolates at 24 h by direct CHROMagar, there were 10 minor and 1 very major error; by MH-GMB there were 12 minor and 2 very major errors; and by standardized CHROMagar Candida there were 13 minor and 2 major errors. There were no very major errors with C. glabrata when all plates were read at 48 h. At 24 h by the direct and standardized CHROMagar the majority of C. glabrata isolates were more resistant, whereas by MH-GMB they were more

Indirect effects of climate changes on cadmium bioavailability and biological effects in the Mediterranean mussel Mytilus galloprovincialis.

PubMed

Nardi, Alessandro; Mincarelli, Luana Fiorella; Benedetti, Maura; Fattorini, Daniele; d'Errico, Giuseppe; Regoli, Francesco

2017-02-01

Despite the great interest in the consequences of climate change on the physiological functioning of marine organisms, indirect and interactive effects of rising temperature and pCO 2 on bioaccumulation and responsiveness to environmental pollutants are still poorly explored, particularly in terms of cellular mechanisms. According to future projections of temperature and pH/pCO 2 , this study investigated the main cellular pathways involved in metal detoxification and oxidative homeostasis in Mediterranean mussels, Mytilus galloprovincialis, exposed for 4 weeks to various combinations of two levels of pH/pCO 2 (8.2/∼400 μatm and 7.4/∼3000 μatm), temperature (20 and 25 °C), and cadmium addition (0 and 20 μg/L). Bioaccumulation was increased in metal exposed organisms but it was not further modulated by different temperature and pH/pCO 2 combinations. However, interactions between temperature, pH and cadmium had significant effects on induction of metallothioneins, responses of the antioxidant system and the onset of oxidative damages, which was tissue dependent. Multiple stressors increased metallothioneins concentrations in the digestive gland revealing different oxidative effects: while temperature and cadmium enhanced glutathione-dependent antioxidant protection and capability to neutralize peroxyl radicals, the metal increased the accumulation of lipid peroxidation products under acidified conditions. Gills did not reveal specific effects for different combinations of factors, but a general stress condition was observed in this tissue after various treatments. Significant variations of immune system were mainly caused by increased temperature and low pH, while co-exposure to acidification and cadmium enhanced metal genotoxicity and the onset of permanent DNA damage in haemocytes. Elaboration of the whole biomarker data in a cellular hazard index, corroborated the synergistic effects of temperature and acidification which increased the toxicological

Use of Molecular Methods for the Rapid Mass Detection of Schistosoma mansoni (Platyhelminthes: Trematoda) in Biomphalaria spp. (Gastropoda: Planorbidae)

PubMed Central

Jannotti-Passos, Liana Konovaloffi; Dos Santos Carvalho, Omar

2017-01-01

The low stringency-polymerase chain reaction (LS-PCR) and loop-mediated isothermal amplification (LAMP) assays were used to detect the presence of S. mansoni DNA in (1) Brazilian intermediate hosts (Biomphalaria glabrata, B. straminea, and B. tenagophila) with patent S. mansoni infections, (2) B. glabrata snails with prepatent S. mansoni infections, (3) various mixtures of infected and noninfected snails; and (4) snails infected with other trematode species. The assays showed high sensitivity and specificity and could detect S. mansoni DNA when one positive snail was included in a pool of 1,000 negative specimens of Biomphalaria. These molecular approaches can provide a low-cost, effective, and rapid method for detecting the presence of S. mansoni in pooled samples of field-collected Biomphalaria. These assays should aid mapping of transmission sites in endemic areas, especially in low prevalence regions and improve schistosomiasis surveillance. It will be a useful tool to monitor low infection rates of snails in areas where control interventions are leading towards the elimination of schistosomiasis. PMID:28246533

An Effective Big Data Supervised Imbalanced Classification Approach for Ortholog Detection in Related Yeast Species

PubMed Central

Galpert, Deborah; del Río, Sara; Herrera, Francisco; Ancede-Gallardo, Evys; Antunes, Agostinho; Agüero-Chapin, Guillermin

2015-01-01

Orthology detection requires more effective scaling algorithms. In this paper, a set of gene pair features based on similarity measures (alignment scores, sequence length, gene membership to conserved regions, and physicochemical profiles) are combined in a supervised pairwise ortholog detection approach to improve effectiveness considering low ortholog ratios in relation to the possible pairwise comparison between two genomes. In this scenario, big data supervised classifiers managing imbalance between ortholog and nonortholog pair classes allow for an effective scaling solution built from two genomes and extended to other genome pairs. The supervised approach was compared with RBH, RSD, and OMA algorithms by using the following yeast genome pairs: Saccharomyces cerevisiae-Kluyveromyces lactis, Saccharomyces cerevisiae-Candida glabrata, and Saccharomyces cerevisiae-Schizosaccharomyces pombe as benchmark datasets. Because of the large amount of imbalanced data, the building and testing of the supervised model were only possible by using big data supervised classifiers managing imbalance. Evaluation metrics taking low ortholog ratios into account were applied. From the effectiveness perspective, MapReduce Random Oversampling combined with Spark SVM outperformed RBH, RSD, and OMA, probably because of the consideration of gene pair features beyond alignment similarities combined with the advances in big data supervised classification. PMID:26605337

PI3K-AKT signaling pathway is involved in hypoxia/thermal-induced immunosuppression of small abalone Haliotis diversicolor.

PubMed

Sun, Yulong; Zhang, Xin; Wang, Guodong; Lin, Shi; Zeng, Xinyang; Wang, Yilei; Zhang, Ziping

2016-12-01

The PI3K-AKT signal pathway has been found to be involved in many important physiological and pathological processes of the innate immune system of vertebrates and invertebrates. In this study, the AKT (HdAKT) and PI3K (HdPI3K) gene of small abalone Haliotis diversicolor were cloned and characterized for the important status of PI3K and AKT protein in PI3K-AKT signaling pathway. The full length cDNAs of HdAKT and HdPI3K are 2126 bp and 6052 bp respectively, encoding proteins of 479 amino acids and 1097 amino acids, respectively. The mRNA expression level of fourteen genes in the PI3K-AKT signaling pathway were detected by quantitative real-time PCR. The results showed that all these fourteen genes were ubiquitously expressed in seven selected tissues. Meanwhile, HdAKT was expressed in haemocytes with the highest expression level (p < 0.05) next in hepatopancreas (p < 0.05). On the other hand, the expression level of HdPI3K in haemocytes was higher than other tissues. Under normal condition, the gene expression level of HdAKT, HdPI3K, and other PI3K-AKT signaling pathway members were significantly up-regulated by Vibrio parahaemolyticus infection which demonstrated that HdAKT, HdPI3K, and other PI3K-AKT signaling pathway members play a role in the innate immune system of abalone. The mRNA expression of these genes in gills, haemocytes and hepatopancreas was significantly down-regulated after the Vibrio parahaemolyticus stimulation with environment stimulation (thermal, hypoxia and thermal & hypoxia). These results indicate that the dual/multiple stresses defeat the immune system and lead to immunosuppression in abalone. PI3K-AKT signaling pathway may be involved in hypoxia/thermal-induced immunosuppression of small abalone Haliotis diversicolor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of white shrimp Litopenaeus vannamei integrin β and its role in immunomodulation by dsRNA-mediated gene silencing.

PubMed

Lin, Yong-Chin; Chen, Jiann-Chu; Chen, Yu-Yuan; Liu, Chun-Hung; Cheng, Winton; Hsu, Chih-Hung; Tsui, Wen-Ching

2013-06-01

The full sequence of white shrimp Litopenaeus vannamei integrin β (LV-B) is 2879bp which encodes 787 amino acids (aa) of the open reading frame (ORF). The mature protein (764 aa) contains (1) an extracellular domain (ED) of 692 aa, (2) a transmembrane domain (TD) of 23 aa, and (3) a cytoplasmic domain (CD) of 49 aa. The cloned LV-B grouped together with crayfish Pacifastacus leniusculus integrin β (PL-B1), but was far away from vertebrate integrin β1, β3, β5, β6, β7, and β8, and another L. vannamei integrin β (LV). A Southern blot analysis indicated that the cloned LV-B was a single copy of genomic DNA. LV-B mRNA was expressed in all tissues, and was highly expressed in haemocytes. LV-B was downregulated in shrimp 24 and 96h after having received white spot syndrome virus (WSSV). LV-B expression by haemocytes of shrimp was higher in the postmoult (A and B) stage, and lower in the premoult (D2/D3) stage. LV-B expression was significantly higher by shrimp reared in 2.5‰ and 5‰ salinities. Shrimp injected with integrin β dsRNA showed gene silencing of integrin β after 36h. LV-B-silenced shrimp showed decreased hyaline cells (HCs), granular cells (GCs, including semi-granular cells), the total haemocyte count (THC), respiratory bursts (RBs), and lysozyme activity, but showed increased RB/HC, superoxide dismutase (SOD) activity/HC, and the phenoloxidase (PO) activity/GC. LV-B-silenced shrimp showed upregulated expressions of lipopolysaccharide- and β-glucan-binding protein (LGBP), peroxinectin (PX), prophenoloxidase I (proPO I), proPO II, proPO-activating enzyme (ppA), α2-macroglobulin (α2-M), cytMnSOD, mtMnSOD, and heat shock protein 70 (HSP70). It was concluded that integrin β plays important roles in proPO activation, phagocytosis, and the antioxidant system for immunomodulation in shrimp. Copyright © 2013 Elsevier Ltd. All rights reserved.

Antifungal Activity of Lactic Acid Bacteria Strains Isolated from Natural Honey against Pathogenic Candida Species

PubMed Central

Bulgasem, Bulgasem Y.; Lani, Mohd Nizam; Wan Yusoff, Wan Mohtar; Fnaish, Sumaya G.

2016-01-01

The role of lactic acid bacteria (LAB) in honey as antifungal activity has received little attention and their mechanism of inhibitory of fungi is not fully understood. In this study, LAB were isolated from honey samples from Malaysia, Libya, Saudi Arabia, and Yemen. Twenty-five isolates were confirmed LAB by catalase test and Gram staining, and were screened for antifungal activity. Four LAB showed inhibitory activity against Candida spp. using the dual agar overlay method. And they were identified as Lactobacillus plantarum HS isolated from Al-Seder honey, Lactobacillus curvatus HH isolated from Al-Hanon honey, Pediococcus acidilactici HC isolated from Tualang honey and Pediococcus pentosaceus HM isolated from Al-Maray honey by the 16S rDNA sequence. The growth of Candida glabrata ATCC 2001 was strongly inhibited (>15.0 mm) and (10~15 mm) by the isolates of L. curvatus HH and P. pentosaceus HM, respectively. The antifungal activity of the crude supernatant (cell free supernatant, CFS) was evaluated using well diffusion method. The CFS showed high antifungal activity against Candida spp. especially The CFS of L. curvatus HH was significantly (p < 0.05) inhibited growth of C. glabrata ATCC 2001, C. parapsilosis ATCC 2201, and C. tropicalis ATCC 750 with inhibitory zone 22.0, 15.6, and 14.7 mm, respectively. While CFS of P. pentosaceus HM was significantly (p < 0.05) effective against C. krusei, C. glabrata, and C. albicans with inhibition zone 17.2, 16.0, and 13.3 mm, respectively. The results indicated that LAB isolated from honey produced compounds which can be used to inhibit the growth of the pathogenic Candida species. PMID:28154488

Antifungal Activity of Lactic Acid Bacteria Strains Isolated from Natural Honey against Pathogenic Candida Species.

PubMed

Bulgasem, Bulgasem Y; Lani, Mohd Nizam; Hassan, Zaiton; Wan Yusoff, Wan Mohtar; Fnaish, Sumaya G

2016-12-01

The role of lactic acid bacteria (LAB) in honey as antifungal activity has received little attention and their mechanism of inhibitory of fungi is not fully understood. In this study, LAB were isolated from honey samples from Malaysia, Libya, Saudi Arabia, and Yemen. Twenty-five isolates were confirmed LAB by catalase test and Gram staining, and were screened for antifungal activity. Four LAB showed inhibitory activity against Candida spp. using the dual agar overlay method. And they were identified as Lactobacillus plantarum HS isolated from Al-Seder honey, Lactobacillus curvatus HH isolated from Al-Hanon honey, Pediococcus acidilactici HC isolated from Tualang honey and Pediococcus pentosaceus HM isolated from Al-Maray honey by the 16S rDNA sequence. The growth of Candida glabrata ATCC 2001 was strongly inhibited (>15.0 mm) and (10~15 mm) by the isolates of L. curvatus HH and P. pentosaceus HM, respectively. The antifungal activity of the crude supernatant (cell free supernatant, CFS) was evaluated using well diffusion method. The CFS showed high antifungal activity against Candida spp. especially The CFS of L. curvatus HH was significantly ( p < 0.05) inhibited growth of C. glabrata ATCC 2001, C. parapsilosis ATCC 2201, and C. tropicalis ATCC 750 with inhibitory zone 22.0, 15.6, and 14.7 mm, respectively. While CFS of P. pentosaceus HM was significantly ( p < 0.05) effective against C. krusei , C. glabrata , and C. albicans with inhibition zone 17.2, 16.0, and 13.3 mm, respectively. The results indicated that LAB isolated from honey produced compounds which can be used to inhibit the growth of the pathogenic Candida species.

Comparison of broth macrodilution, broth microdilution, and E test antifungal susceptibility tests for fluconazole.

PubMed Central

Sewell, D L; Pfaller, M A; Barry, A L

1994-01-01

A comparison of the E test, the broth microdilution test, and the reference broth macrodilution susceptibility test of the National Committee for Clinical Laboratory Standards for fluconazole susceptibility testing was performed with 238 clinical isolates of Candida species and Torulopsis (Candida) glabrata. An 80% inhibition endpoint MIC was determined by the reference broth macrodilution method after 48 h of incubation. The MICs obtained by the two study methods were read after 24 and 48 h of incubation. Overall, excellent agreement within 2 doubling dilutions was obtained between the broth microdilution and the broth macrodilution methods for the combined results for all species at both 24 h (93%) and 48 h (94%). The correlation of 24-h MIC endpoints between the E test and the broth macrodilution methods was 37% for T. glabrata, 56% for Candida tropicalis, 93% for Candida albicans, and 90% for other Candida species. The percent agreement at 48 h ranged from 34% for T. glabrata to 97% for Candida species other than C. albicans and C. tropicalis. These initial results support the further evaluation of the E test as an alternative method for fluconazole susceptibility testing of Candida species. PMID:7814531

Epidemiology of echinocandin resistance in Candida

PubMed Central

Grossman, Nina T.; Chiller, Tom M.; Lockhart, Shawn R.

2018-01-01

Echinocandins are the newest antifungal agents approved for use in treating Candida infections in the US. They act by interfering with 1,3-β-D-glucan synthase and therefore disrupt cell wall production and lead to Candida cell death. There is no intrinsic resistance to echinocandins among Candida species, and isolates from historic collections archived before the release of the echinocandins show no resistance. Resistance to the echinocandins remains low among most Candida species and ranges overall from 0–1%. Among isolates of Candida glabrata, the proportion of resistant isolates is higher and has been reported to be as high as 13.5% in at least one hospital. Antifungal resistance is due to specific amino acid mutations in the Fksp subunit(s) of the 1,3-β-D-glucan synthase protein which are localized to one of two hotspots. These mutations are being recognized in isolates from patients who have failed echinocandin therapy, and often lead to a poor outcome. While the future looks bright for the echinocandins against most Candida species, C. glabrata remains a species of concern and resistance rates of C. glabrata to the echinocandins should be monitored closely. PMID:29780439

Epidemiology of echinocandin resistance in Candida.

PubMed

Grossman, Nina T; Chiller, Tom M; Lockhart, Shawn R

2014-12-01

Echinocandins are the newest antifungal agents approved for use in treating Candida infections in the US. They act by interfering with 1,3-β-D-glucan synthase and therefore disrupt cell wall production and lead to Candida cell death. There is no intrinsic resistance to echinocandins among Candida species, and isolates from historic collections archived before the release of the echinocandins show no resistance. Resistance to the echinocandins remains low among most Candida species and ranges overall from 0-1%. Among isolates of Candida glabrata , the proportion of resistant isolates is higher and has been reported to be as high as 13.5% in at least one hospital. Antifungal resistance is due to specific amino acid mutations in the Fksp subunit(s) of the 1,3-β-D-glucan synthase protein which are localized to one of two hotspots. These mutations are being recognized in isolates from patients who have failed echinocandin therapy, and often lead to a poor outcome. While the future looks bright for the echinocandins against most Candida species, C. glabrata remains a species of concern and resistance rates of C. glabrata to the echinocandins should be monitored closely.

The upregulation of immune responses in tyrosine hydroxylase (TH) silenced Litopenaeus vannamei.

PubMed

Mapanao, Ratchaneegorn; Chang, Chin-Chyuan; Cheng, Winton

2017-02-01

Catecholamines (CAs) play a crucial role in maintaining physiological and immune homeostasis in invertebrates and vertebrates under stressful conditions. Tyrosine hydroxylase (TH) is the first and rate-limiting enzyme in CA synthesis. To develop an effective CA-related immunological defense system against stress and pathogen infection, various criteria, were evaluated in TH double-stranded (ds) RNA-injected white shrimp, Litopenaeus vannamei. Specifically, the relative transcript quantification of TH, dopamine β-hydroxylase (DBH), crustacean hyperglycemic hormone (CHH), and other immune-related genes; TH activity in the haemolymph; and the estimation of l-dihydroxyphenylalanine (l-DOPA), glucose, and lactate levels in the haemolymph were examined. TH depletion revealed a significant increase in the total haemocyte count; granular cells; semigranular cells; respiratory bursts (RBs, release of superoxide anion); superoxide dismutase (SOD) activity; phagocytic activity and clearance efficiency; and the expression of lipopolysaccharide and β-1,3-glucan-binding protein and peroxinectin, SOD, crustin, and lysozyme genes. In addition, the reduction of TH gene expression and activity was accompanied by a decline of phenoloxidase (PO) activity per granulocyte, lower glucose and lactate levels, and significantly low expression of DBH and CHH genes. However, the number of hyaline cells, activity of PO, RBs per haemocyte, and expression of POI and POII genes were not significantly different in the LvTH-silenced shrimp. Notably, the survival ratio of LvTH-silenced shrimp was significantly higher than that of shrimp injected with diethyl pyrocarbonate-water and nontargeting dsRNA when challenged with Vibrio alginolyticus. Therefore, the depletion of TH can enhance disease resistance in shrimp by upregulating specific immune parameters but downregulating the levels of carbohydrate metabolites. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of hot-water extract of banana (Musa acuminata) fruit's peel on the antibacterial activity, and anti-hypothermal stress, immune responses and disease resistance of the giant freshwater prawn, Macrobrachium rosenbegii.

PubMed

Rattanavichai, Wutti; Cheng, Winton

2014-08-01

The hot-extracts isolated from fruit's peel of banana, Musa acuminata, was evaluated on the antibacterial activity to pathogens from aquatic animals, and immunostimulating potential, disease resistance and anti-hypothermal stress in giant freshwater prawn, Macrobrachium rosenbergii through injection administration. The banana peel extract (BPE) showed good activity against 1 Gram-positive and 3 Gram-negative pathogens, including Lactococcus garvieae, Photobacteria damsella, Vibrio alginolyticus and Vibrio parahemolyticus especially in prawn pathogen of L. garvieae strain, which were carried out by a disk diffusion method. Prawn received BPE via injection administration at 1-6 μg (g prawn)(-1) significantly increased total haemocyte count (THC), hyaline cell (HC), granular cell (GC), phenoloxidase (PO) activity and phagocytic activity against L. garvieae from 3 to 6 days, and significantly increased clearance efficiency against L. garvieae and a significantly decreased coagulation time of prawn from 1 to 6 days. Prawn injected with BPE at 6.0 μg (g prawn)(-1) for 6 days showed significantly increased superoxide dismutase (SOD) activity, but significantly decreased respiratory bursts (RBs) of per haemocyte. Survival rates of M. rosenbergii injected with BPE at concentrations of 1, 3 and 6 μg (g prawn)(-1) were significantly higher than those injected with saline control after challenge with L. garvieae for 4-6 days, and the respective relative survival percentages of prawn were 28.6%, 38.1%, and 47.8%, respectively at 6 days. The sublethal time of prawns that had received saline and BPE at 1, 3 and 6 μg (g prawn)(-1) for 6 days and then were transferred from 28 °C to 14 °C were 69.4, 79.8, 83.6, and 90.2 h, respectively. It was concluded that the BPE can be used as the bacteriostat, and immunostimulant and physiological regulator for prawn through injection administration to enhance immunity, physiological responses, and resistance against L. garvieae

Limiting immunopathology: Interaction between carotenoids and enzymatic antioxidant defences.

PubMed

Babin, A; Saciat, C; Teixeira, M; Troussard, J-P; Motreuil, S; Moreau, J; Moret, Y

2015-04-01

The release of reactive oxygen and nitrogen species (ROS and RNS) during the inflammatory response generates damages to host tissues, referred to as immunopathology, and is an important factor in ecological immunology. The integrated antioxidant system, comprising endogenous antioxidant enzymes (e.g. superoxide dismutase SOD, and catalase CAT) and dietary antioxidants (e.g. carotenoids), helps to cope with immune-mediated oxidative stress. Crustaceans store large amounts of dietary carotenoids for yet unclear reasons. While being immunostimulants and antioxidants, the interaction of these pigments with antioxidant enzymes remains unclear. Here, we tested the interaction between dietary supplementation with carotenoids and immune challenge on immune defences and the activity of the antioxidant enzymes SOD and CAT, in the amphipod crustacean Gammarus pulex. Dietary supplementation increased the concentrations of circulating carotenoids and haemocytes in the haemolymph, while the immune response induced the consumption of circulating carotenoids and a drop of haemocyte density. Interestingly, supplemented gammarids exhibited down-regulated SOD activity but high CAT activity compared to control ones. Our study reveals specific interactions of dietary carotenoids with endogenous antioxidant enzymes, and further underlines the potential importance of carotenoids in the evolution of immunity and/or of antioxidant mechanisms in crustaceans. Copyright © 2014 Elsevier Ltd. All rights reserved.

Antifungal Susceptibilities of Candida Species Causing Vulvovaginitis and Epidemiology of Recurrent Cases

PubMed Central

Richter, Sandra S.; Galask, Rudolph P.; Messer, Shawn A.; Hollis, Richard J.; Diekema, Daniel J.; Pfaller, Michael A.

2005-01-01

There are limited data regarding the antifungal susceptibility of yeast causing vulvovaginal candidiasis, since cultures are rarely performed. Susceptibility testing was performed on vaginal yeast isolates collected from January 1998 to March 2001 from 429 patients with suspected vulvovaginal candidiasis. The charts of 84 patients with multiple positive cultures were reviewed. The 593 yeast isolates were Candida albicans (n = 420), Candida glabrata (n = 112), Candida parapsilosis (n = 30), Candida krusei (n = 12), Saccharomyces cerevisiae ( n = 9), Candida tropicalis (n = 8), Candida lusitaniae (n = 1), and Trichosporon sp. (n = 1). Multiple species suggesting mixed infection were isolated from 27 cultures. Resistance to fluconazole and flucytosine was observed infrequently (3.7% and 3.0%); 16.2% of isolates were resistant to itraconazole (MIC ≥ 1 μg/ml). The four imidazoles (econazole, clotrimazole, miconazole, and ketoconazole) were active: 94.3 to 98.5% were susceptible at ≤1 μg/ml. Among different species, elevated fluconazole MICs (≥16 μg/ml) were only observed in C. glabrata (15.2% resistant [R], 51.8% susceptible-dose dependent [S-DD]), C. parapsilosis (3.3% S-DD), S. cerevisiae (11.1% S-DD), and C. krusei (50% S-DD, 41.7% R, considered intrinsically fluconazole resistant). Resistance to itraconazole was observed among C. glabrata (74.1%), C. krusei (58.3%), S. cerevisiae (55.6%), and C. parapsilosis (3.4%). Among 84 patients with recurrent episodes, non-albicans species were more common (42% versus 20%). A ≥4-fold rise in fluconazole MIC was observed in only one patient with C. parapsilosis. These results support the use of azoles for empirical therapy of uncomplicated candidal vulvovaginitis. Recurrent episodes are more often caused by non-albicans species, for which azole agents are less likely to be effective. PMID:15872235

Antimicrobial and antioxidant activities of plants from northeast of Mexico.

PubMed

Salazar-Aranda, Ricardo; Pérez-López, Luis Alejandro; López-Arroyo, Joel; Alanís-Garza, Blanca Alicia; Waksman de Torres, Noemí

2011-01-01

Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 μg ml(-1). We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125 μg ml(-1)), C. glabrata (MICs 31.25 μg ml(-1)) and C. parapsilosis (MICs between 31.25 and 125 μg ml(-1)); Chrysanctinia mexicana against C. glabrata (MICs 31.25 μg ml(-1)); Colubrina greggii against E. faecalis (MICs 250 μg ml(-1)) and Cordia boissieri against C. glabrata (MIC 125 μg ml(-1)). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri.

Antimicrobial and Antioxidant Activities of Plants from Northeast of Mexico

PubMed Central

Salazar-Aranda, Ricardo; Pérez-López, Luis Alejandro; López-Arroyo, Joel; Alanís-Garza, Blanca Alicia; Waksman de Torres, Noemí

2011-01-01

Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 μg ml−1. We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125 μg ml−1), C. glabrata (MICs 31.25 μg ml−1) and C. parapsilosis (MICs between 31.25 and 125 μg ml−1); Chrysanctinia mexicana against C. glabrata (MICs 31.25 μg ml−1); Colubrina greggii against E. faecalis (MICs 250 μg ml−1) and Cordia boissieri against C. glabrata (MIC 125 μg ml−1). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri. PMID:19770266

Clinical efficacy and health implications of inconsistency in different production batches of antimycotic drugs in a developing country.

PubMed

Ogunshe, Adenike A O; Adepoju, Adedayo A; Oladimeji, Modupe E

2011-01-01

This study aimed at evaluating the in vitro efficacy and health implications of inconsistencies in different production batches of antimycotic drugs. in vitro susceptibility profiles of 36 Candida spp. - C. albicans (19.4%), C. glabrata (30.6%), C. tropicalis (33.3%), and C. pseudotropicalis (16.7%) - obtained from human endocervical and high vaginal swabs (ECS/HVS) to two different batches (B1 and B2) of six antimycotic drugs (clotrimazole, doxycycline, iconazole, itraconazole, metronidazole and nystatin) was determined using modified agar well-diffusion method. None of the Candida strains had entirely the same (100%) susceptibility / resistance profiles in both batches of corresponding antimycotic drugs; while, different multiple antifungal susceptibility (MAS) rates were also recorded in batches 1 and 2 for corresponding antifungals. Only 14.3%, 27.3%, 16.7-33.3%, and 8.3-25.0% of C. albicans, C. glabrata, C. pseudotropicalis, and C. tropicalis strains, respectively, had similar susceptibility/resistance profiles toward coressponding antifungal agents in both batches; while up to 57.1% of C. albicans, 45.5% of C. glabrata, 66.7% of C. pseudotropicalis, and 50.0% of C. tropicalis strains were susceptible to one batch of antifungals but resistant to corresponding antifungals in the second batch. As high as 71.4% (C. albicans), 73.0% (C. glabrata), 50.0% (C. pseudotropicalis), and 66.74% (C. tropicalis) strains had differences of ≥ 10.0 mm among corresponding antimycotic agents. Candida strains exhibited different in vitro susceptibility / resistance patterns toward two batches of corresponding antimycotic agents, which has clinical implications on the efficacy of the drugs and treatment of patients. The findings of the present study will be of benefit in providing additional information in support of submission of drugs for registration to appropriate regulatory agencies.

Clinical efficacy and health implications of inconsistency in different production batches of antimycotic drugs in a developing country

PubMed Central

Ogunshe, Adenike A. O.; Adepoju, Adedayo A.; Oladimeji, Modupe E.

2011-01-01

Objective: This study aimed at evaluating the in vitro efficacy and health implications of inconsistencies in different production batches of antimycotic drugs. Materials and Methods: in vitro susceptibility profiles of 36 Candida spp. – C. albicans (19.4%), C. glabrata (30.6%), C. tropicalis (33.3%), and C. pseudotropicalis (16.7%) – obtained from human endocervical and high vaginal swabs (ECS/HVS) to two different batches (B1 and B2) of six antimycotic drugs (clotrimazole, doxycycline, iconazole, itraconazole, metronidazole and nystatin) was determined using modified agar well-diffusion method. Results: None of the Candida strains had entirely the same (100%) susceptibility / resistance profiles in both batches of corresponding antimycotic drugs; while, different multiple antifungal susceptibility (MAS) rates were also recorded in batches 1 and 2 for corresponding antifungals. Only 14.3%, 27.3%, 16.7-33.3%, and 8.3-25.0% of C. albicans, C. glabrata, C. pseudotropicalis, and C. tropicalis strains, respectively, had similar susceptibility/resistance profiles toward coressponding antifungal agents in both batches; while up to 57.1% of C. albicans, 45.5% of C. glabrata, 66.7% of C. pseudotropicalis, and 50.0% of C. tropicalis strains were susceptible to one batch of antifungals but resistant to corresponding antifungals in the second batch. As high as 71.4% (C. albicans), 73.0% (C. glabrata), 50.0% (C. pseudotropicalis), and 66.74% (C. tropicalis) strains had differences of ≥ 10.0 mm among corresponding antimycotic agents. Conclusions: Candida strains exhibited different in vitro susceptibility / resistance patterns toward two batches of corresponding antimycotic agents, which has clinical implications on the efficacy of the drugs and treatment of patients. The findings of the present study will be of benefit in providing additional information in support of submission of drugs for registration to appropriate regulatory agencies. PMID:21430967

Limitations of the Current Microbial Identification System for Identification of Clinical Yeast Isolates

PubMed Central

Kellogg, James A.; Bankert, David A.; Chaturvedi, Vishnu

1998-01-01

The ability of the rapid, computerized Microbial Identification System (MIS; Microbial ID, Inc.) to identify a variety of clinical isolates of yeast species was compared to the abilities of a combination of tests including the Yeast Biochemical Card (bioMerieux Vitek), determination of microscopic morphology on cornmeal agar with Tween 80, and when necessary, conventional biochemical tests and/or the API 20C Aux system (bioMerieux Vitek) to identify the same yeast isolates. The MIS chromatographically analyzes cellular fatty acids and compares the results with the fatty acid profiles in its database. Yeast isolates were subcultured onto Sabouraud dextrose agar and were incubated at 28°C for 24 h. The resulting colonies were saponified, methylated, extracted, and chromatographically analyzed (by version 3.8 of the MIS YSTCLN database) according to the manufacturer’s instructions. Of 477 isolates of 23 species tested, 448 (94%) were given species names by the MIS and 29 (6%) were unidentified (specified as “no match” by the MIS). Of the 448 isolates given names by the MIS, only 335 (75%) of the identifications were correct to the species level. While the MIS correctly identified only 102 (82%) of 124 isolates of Candida glabrata, the predictive value of an MIS identification of unknown isolates as C. glabrata was 100% (102 of 102) because no isolates of other species were misidentified as C. glabrata. In contrast, while the MIS correctly identified 100% (15 of 15) of the isolates of Saccharomyces cerevisiae, the predictive value of an MIS identification of unknown isolates as S. cerevisiae was only 47% (15 of 32), because 17 isolates of C. glabrata were misidentified as S. cerevisiae. The low predictive values for accuracy associated with MIS identifications for most of the remaining yeast species indicate that the procedure and/or database for the system need to be improved. PMID:9574676

Whole genome analysis of a schistosomiasis-transmitting freshwater snail

PubMed Central

Adema, Coen M.; Hillier, LaDeana W.; Jones, Catherine S.; Loker, Eric S.; Knight, Matty; Minx, Patrick; Oliveira, Guilherme; Raghavan, Nithya; Shedlock, Andrew; do Amaral, Laurence Rodrigues; Arican-Goktas, Halime D.; Assis, Juliana G.; Baba, Elio Hideo; Baron, Olga L.; Bayne, Christopher J.; Bickham-Wright, Utibe; Biggar, Kyle K.; Blouin, Michael; Bonning, Bryony C.; Botka, Chris; Bridger, Joanna M.; Buckley, Katherine M.; Buddenborg, Sarah K.; Lima Caldeira, Roberta; Carleton, Julia; Carvalho, Omar S.; Castillo, Maria G.; Chalmers, Iain W.; Christensens, Mikkel; Clifton, Sandra; Cosseau, Celine; Coustau, Christine; Cripps, Richard M.; Cuesta-Astroz, Yesid; Cummins, Scott F.; di Stefano, Leon; Dinguirard, Nathalie; Duval, David; Emrich, Scott; Feschotte, Cédric; Feyereisen, Rene; FitzGerald, Peter; Fronick, Catrina; Fulton, Lucinda; Galinier, Richard; Gava, Sandra G.; Geusz, Michael; Geyer, Kathrin K.; Giraldo-Calderón, Gloria I.; de Souza Gomes, Matheus; Gordy, Michelle A.; Gourbal, Benjamin; Grunau, Christoph; Hanington, Patrick C.; Hoffmann, Karl F.; Hughes, Daniel; Humphries, Judith; Jackson, Daniel J.; Jannotti-Passos, Liana K.; de Jesus Jeremias, Wander; Jobling, Susan; Kamel, Bishoy; Kapusta, Aurélie; Kaur, Satwant; Koene, Joris M.; Kohn, Andrea B.; Lawson, Dan; Lawton, Scott P; Liang, Di; Limpanont, Yanin; Liu, Sijun; Lockyer, Anne E.; Lovato, TyAnna L.; Ludolf, Fernanda; Magrini, Vince; McManus, Donald P.; Medina, Monica; Misra, Milind; Mitta, Guillaume; Mkoji, Gerald M.; Montague, Michael J.; Montelongo, Cesar; Moroz, Leonid L.; Munoz-Torres, Monica C.; Niazi, Umar; Noble, Leslie R.; Oliveira, Francislon S.; Pais, Fabiano S.; Papenfuss, Anthony T.; Peace, Rob; Pena, Janeth J.; Pila, Emmanuel A.; Quelais, Titouan; Raney, Brian J.; Rast, Jonathan P.; Rollinson, David; Rosse, Izinara C.; Rotgans, Bronwyn; Routledge, Edwin J.; Ryan, Kathryn M.; Scholte, Larissa L. S.; Storey, Kenneth B.; Swain, Martin; Tennessen, Jacob A.; Tomlinson, Chad; Trujillo, Damian L.; Volpi, Emanuela V.; Walker, Anthony J.; Wang, Tianfang; Wannaporn, Ittiprasert; Warren, Wesley C.; Wu, Xiao-Jun; Yoshino, Timothy P.; Yusuf, Mohammed; Zhang, Si-Ming; Zhao, Min; Wilson, Richard K.

2017-01-01

Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis. PMID:28508897

Epidemiological investigation of Candida species causing bloodstream infection in paediatric small bowel transplant recipients.

PubMed

Suhr, Mallory J; Gomes-Neto, João Carlos; Banjara, Nabaraj; Florescu, Diana F; Mercer, David F; Iwen, Peter C; Hallen-Adams, Heather E

2017-06-01

Small bowel transplantation (SBT) can be a life-saving medical procedure. However, these recipients experience high risk of bloodstream infections caused by Candida. This research aims to characterise the SBT recipient gut microbiota over time following transplantation and investigate the epidemiology of candidaemia in seven paediatric patients. Candida species from the recipients' ileum and bloodstream were identified by internal transcribed spacer sequence and distinguished to strain by multilocus sequence typing and randomly amplified polymorphic DNA. Antifungal susceptibility of bloodstream isolates was determined against nine antifungals. Twenty-two ileostomy samples harboured at least one Candida species. Fungaemia were caused by Candida parapsilosis, Candida albicans, Candida glabrata, Candida orthopsilosis and Candida pelliculosa. All but three bloodstream isolates showed susceptibility to all the antifungals tested. One C. glabrata isolate showed multidrug resistance to itraconazole, amphotericin B and posaconazole and intermediate resistance to caspofungin. Results are congruent with both endogenous (C. albicans, C. glabrata) and exogenous (C. parapsilosis) infections; results also suggest two patients were infected by the same strain of C. parapsilosis. Continuing to work towards a better understanding of sources of infection-particularly the exogenous sources-would lead to targeted prevention strategies. © 2017 Blackwell Verlag GmbH.

Promising results of cranberry in the prevention of oral Candida biofilms.

PubMed

Girardot, Marion; Guerineau, Amandine; Boudesocque, Leslie; Costa, Damien; Bazinet, Laurent; Enguehard-Gueiffier, Cécile; Imbert, Christine

2014-04-01

In the context of dental caries prevention by natural foodstuff sources, antifungal and antibiofilm activities of dry commercial extracts of cranberry fruit (Vaccinium macrocarpon Aiton) and two other red fruits (Vaccinium myrtillus L. and Malpighia punicifolia L.) were assessed on Candida albicans and Candida glabrata yeasts. When added to the culture medium, the cranberry extract displayed a significant anti-adhesion activity against Candida spp. when used at low concentrations. In addition, the pretreatment of surfaces with this extract induced an anti-adhesion activity mainly against C. glabrata yeasts and an antibiofilm activity against C. albicans. This activity was dependent on concentration, species, and strain. A phytochemical investigation bioguided by anti-adhesion tests against the two Candida species was carried out on crude cranberry juice to determine the active fractions. Three subfractions enriched in proanthocyanidins showed an anti-adhesion activity at low concentrations. This study investigated for the first time the interest of crude extracts of cranberry and cranberry juice fractions to prevent biofilms of C. glabrata. It highlighted the potency of consuming this fruit and using it as a source of anti-adhesion agents. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Serum albumin promotes ATP-binding cassette transporter-dependent sterol uptake in yeast.

PubMed

Marek, Magdalena; Silvestro, Daniele; Fredslund, Maria D; Andersen, Tonni G; Pomorski, Thomas G

2014-12-01

Sterol uptake in fungi is a multistep process that involves interaction between external sterols and the cell wall, incorporation of sterol molecules into the plasma membrane, and subsequent integration into intracellular membranes for turnover. ATP-binding cassette (ABC) transporters have been implicated in sterol uptake, but key features of their activity remain to be elucidated. Here, we apply fluorescent cholesterol (NBD-cholesterol) to monitor sterol uptake under anaerobic and aerobic conditions in two fungal species, Candida glabrata (Cg) and Saccharomyces cerevisiae (Sc). We found that in both fungal species, ABC transporter-dependent uptake of cholesterol under anaerobic conditions and in mutants lacking HEM1 gene is promoted in the presence of the serum protein albumin that is able to bind the sterol molecule. Furthermore, the C. glabrata ABC transporter CgAus1p expressed in S. cerevisiae requires the presence of serum or albumin for efficient cholesterol uptake. These results suggest that albumin can serve as sterol donor in ABC transporter-dependent sterol uptake, a process potentially important for growth of C. glabrata inside infected humans. © 2014 The Authors. FEMS Yeast Research published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

Prevalence, virulence factors and antifungal susceptibility of Candida spp. isolated from bloodstream infections in a tertiary care hospital in Brazil.

PubMed

Canela, Heliara Maria Spina; Cardoso, Bárbara; Vitali, Lucia Helena; Coelho, Harnoldo Colares; Martinez, Roberto; Ferreira, Márcia Eliana da Silva

2018-01-01

Candida spp. are responsible for 80% of all systemic fungal infections and are associated with high mortality rates. This study characterised 79 bloodstream isolates of C. albicans, C. glabrata, C. orthopsilosis, C. parapsilosis and C. tropicalis from patients in a Brazilian hospital. The susceptibility to amphotericin B, caspofungin, fluconazole and voriconazole was determined; virulence factor production was assessed based on haemolysin, phospholipase and proteinase activities, and the patients' clinical characteristics were analysed. C. albicans was the predominant species (44%), followed by C. glabrata (19%), C. tropicalis (19%), C. parapsilosis (14%) and C. orthopsilosis (4%). The candidemia incidence was 1.52 per 1000 admissions, and the crude mortality rate was 52%. One C. albicans isolate was resistant to fluconazole and voriconazole. Moreover, 20.2%, 2.5% and 3.8% of the isolates exhibited dose-dependent susceptibility to fluconazole, voriconazole and caspofungin, respectively. In conclusion, although the C. glabrata incidence was higher than that usually described in Brazil, its increase was previously observed in studies conducted worldwide. Furthermore, the azole resistance of the C. albicans isolate could be due to previous exposure to these antifungals. These results highlight the importance of epidemiological studies and will facilitate an improved understanding of candidemia in the studied hospital. © 2017 Blackwell Verlag GmbH.

International Surveillance of Bloodstream Infections Due to Candida Species: Frequency of Occurrence and In Vitro Susceptibilities to Fluconazole, Ravuconazole, and Voriconazole of Isolates Collected from 1997 through 1999 in the SENTRY Antimicrobial Surveillance Program

PubMed Central

Pfaller, M. A.; Diekema, D. J.; Jones, R. N.; Sader, H. S.; Fluit, A. C.; Hollis, R. J.; Messer, S. A.

2001-01-01

A surveillance program (SENTRY) of bloodstream infections (BSI) in the United States, Canada, Latin America, and Europe from 1997 through 1999 detected 1,184 episodes of candidemia in 71 medical centers (32 in the United States, 23 in Europe, 9 in Latin America, and 7 in Canada). Overall, 55% of the yeast BSIs were due to Candida albicans, followed by Candida glabrata and Candida parapsilosis (15%), Candida tropicalis (9%), and miscellaneous Candida spp. (6%). In the United States, 45% of candidemias were due to non-C. albicans species. C. glabrata (21%) was the most common non-C. albicans species in the United States, and the proportion of non-C. albicans BSIs was highest in Latin America (55%). C. albicans accounted for 60% of BSI in Canada and 58% in Europe. C. parapsilosis was the most common non-C. albicans species in Latin America (25%), Canada (16%), and Europe (17%). Isolates of C. albicans, C. parapsilosis, and C. tropicalis were all highly susceptible to fluconazole (97 to 100% at ≤8 μg/ml). Likewise, 97 to 100% of these species were inhibited by ≤1 μg/ml of ravuconazole (concentration at which 50% were inhibited [MIC50], 0.007 to 0.03 μg/ml) or voriconazole (MIC50, 0.007 to 0.06 μg/ml). Both ravuconazole and voriconazole were significantly more active than fluconazole against C. glabrata (MIC90s of 0.5 to 1.0 μg/ml versus 16 to 32 μg/ml, respectively). A trend of increased susceptibility of C. glabrata to fluconazole was noted over the three-year period. The percentage of C. glabrata isolates susceptible to fluconazole increased from 48% in 1997 to 84% in 1999, and MIC50s decreased from 16 to 4 μg/ml. A similar trend was documented in both the Americas (57 to 84% susceptible) and Europe (22 to 80% susceptible). Some geographic differences in susceptibility to triazole were observed with Canadian isolates generally more susceptible than isolates from the United States and Europe. These observations suggest susceptibility patterns and trends

An ecotoxicological approach to evaluate the effects of tourism impacts in the Marine Protected Area of La Maddalena (Sardinia, Italy).

PubMed

Moschino, V; Schintu, M; Marrucci, A; Marras, B; Nesto, N; Da Ros, L

2017-09-15

In the Marine Protected Area of La Maddalena Archipelago, environmental protection rules and safeguard measures for nautical activities have helped in reducing anthropogenic pressure; however, tourism related activities remain particularly significant in summer. With the aim of evaluating their impacts, the biomarker approach using transplanted Mytilus galloprovincialis as sentinel organisms coupled with POCIS deployment was applied. Mussels, translocated to four marine areas differently impacted by tourism activities, were sampled before, during and after the tourist season. Moreover, endocrine disruptors in passive samplers POCIS and the cellular toxicity of whole POCIS extracts on mussel haemocytes were evaluated to integrate ecotoxicological information. Lysosomal biomarkers, condition index and mortality rate, as well as metals in tissues suggested an alteration of the health status of mussels transplanted to the most impacted sites. The cellular toxicity of POCIS extracts was pointed out, notwithstanding the concentrations of the examined compounds were always below the detection limits. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigation of the Antifungal Activity and Mode of Action of Thymus vulgaris, Citrus limonum, Pelargonium graveolens, Cinnamomum cassia, Ocimum basilicum, and Eugenia caryophyllus Essential Oils.

PubMed

Gucwa, Katarzyna; Milewski, Sławomir; Dymerski, Tomasz; Szweda, Piotr

2018-05-08

The antimicrobial activity of plant oils and extracts has been recognized for many years. In this study the activity of Thymus vulgaris , Citrus limonum , Pelargonium graveolens , Cinnamomum cassia , Ocimum basilicum , and Eugenia caryophyllus essential oils (EOs) distributed by Pollena Aroma (Nowy Dwór Mazowiecki, Poland) was investigated against a group of 183 clinical isolates of C. albicans and 76 isolates of C. glabrata . All of the oils exhibited both fungistatic and fungicidal activity toward C. albicans and C. glabrata isolates. The highest activity was observed for cinnamon oil, with MIC (Minimum Inhibitory Concentration) values in the range 0.002⁻0.125% ( v / v ). The MIC values of the rest of the oils were in the range 0.005% (or less) to 2.5% ( v / v ). In most cases MFC (Minimum Fungicidal Concentration) values were equal to MIC or twice as high. Additionally, we examined the mode of action of selected EOs. The effect on cell wall components could not be clearly proved. Three of the tested EOs (thyme, lemon, and clove) affected cell membranes. At the same time, thyme, cinnamon, and clove oil influenced potassium ion efflux, which was not seen in the case of lemon oil. All of the tested oils demonstrated the ability to inhibit the transition of yeast to mycelium form, but the effect was the lowest in the case of cinnamon oil.

In Vitro Assessment of the Antimicrobial Efficacy of Optimized Nitroglycerin-Citrate-Ethanol as a Nonantibiotic, Antimicrobial Catheter Lock Solution for Prevention of Central Line-Associated Bloodstream Infections

PubMed Central

Reitzel, Ruth A.; Hirsh-Ginsberg, Cheryl; Murray, Kimberly; Chaftari, Anne-Marie; Hachem, Ray; Raad, Issam

2016-01-01

The rapid, broad-spectrum, biofilm-eradicating activity of the combination of 0.01% nitroglycerin, 7% citrate, and 20% ethanol and its potential as a nonantibiotic, antimicrobial catheter lock solution (ACLS) were previously reported. Here, a nitroglycerin-citrate-ethanol (NiCE) ACLS optimized for clinical assessment was developed by reducing the nitroglycerin and citrate concentrations and increasing the ethanol concentration. Biofilm-eradicating activity was sustained when the ethanol concentration was increased from 20 to 22% which fully compensated for reducing the citrate concentration from 7% to 4% as well as the nitroglycerin concentration from 0.01% to 0.0015% or 0.003%. The optimized formulations demonstrated complete and rapid (2 h) eradication of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate Staphylococcus aureus (VISA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant enterococci (VRE), multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Klebsiella pneumoniae, MDR Enterobacter cloacae, MDR Acinetobacter baumannii, MDR Escherichia coli, MDR Stenotrophomonas maltophilia, Candida albicans, and Candida glabrata biofilms. The optimized NiCE lock solutions demonstrated anticoagulant activities comparable to those of heparin lock solutions. NiCE lock solution was significantly more effective than taurolidine-citrate-heparin lock solution in eradicating biofilms of Staphylococcus aureus and Candida glabrata. The optimized, nonantibiotic, heparin-free NiCE lock solution demonstrates rapid broad-spectrum biofilm eradication as well as effective anticoagulant activity, making NiCE a high-quality ACLS candidate for clinical assessment. PMID:27297475

Cryopreservation of Schistosome Larvae.

DTIC Science & Technology

1980-10-02

anacardic acid, obtained by fractionation of an extract from the cashew nut shell, were tested for toxicity to B. glabrata. The triene form was most toxic...attacked and destroyed muscle cells of the atrium, a reaction against self; 6# 5) Molluscicidal effect of cashew nut shell extract for D. abgata was...Passive unsuliibll !Nd& bl. gjabn phawed amebocytes attacking and destroying mul" ea- Y ad~t effct f cshe nut shell extract for 9, a~ was shown to be due

Fine structure of Mytella falcata (Bivalvia) gill filaments.

PubMed

de Oliveira David, José Augusto; Salaroli, Renato B; Fontanetti, Carmem S

2008-01-01

Bivalve filter feeders are sessile animals that live in constant contact with water and its pollutants. Their gill is an organ highly exposed to these conditions due to its large surface and its involvement in gas exchanges and feeding. The bivalve Mytella falcata is found in estuaries of Latin America, on the Atlantic as well as the Pacific Coast. It is commonly consumed, and sometimes is the only source of protein of low-income communities. In this study, gill filaments of M. falcata were characterized using histology, histochemistry and transmission electron microscopy for future comparative studies among animals exposed to environmental pollutants. Gill filaments may be divided into abfrontal, intermediate and frontal zones. Filaments are interconnected by ciliary discs. In the center of filaments, haemocytes circulate through a haemolymph vessel internally lined by an endothelium and supported by an acellular connective tissue rich in polysaccharides and collagen. The abfrontal zone contains cuboidal cells, while the intermediate zone consists of a simple squamous epithelium. The frontal zone is composed of five columnar cell types: one absorptive, mainly characterized by the presence of pinocytic vesicles in the apical region of the cell; one secretory, rarely observed; and three ciliated with abundant mitochondria. All cells lining the filament exhibit numerous microvilli and seem to absorb substances from the environment. PAS staining was observed in mucous cells in the frontal and abfrontal zones. Bromophenol blue allowed the distinction of haemocytes and detection of a glycoprotein secretion in the secretory cells of the frontal region. The characteristics of M. falcata gill filaments observed in this study were very similar to those of other bivalves, especially other Mytilidae, and are suitable for histopathological studies on the effect of water-soluble pollutants.

Effects of inbreeding and temperature stress on life history and immune function in a butterfly.

PubMed

Franke, K; Fischer, K

2013-03-01

Theory predicts that inbreeding depression should be more pronounced under environmental stress due to an increase in the expression of recessive deleterious alleles. If so, inbred populations may be especially vulnerable to environmental change. Against this background, we here investigate effects of inbreeding, temperature stress and its interactions with inbreeding in the tropical butterfly Bicyclus anynana. We use a full-factorial design with three levels of inbreeding (F = 0/0.25/0.38) and three temperature treatments (2 h exposure to 1, 27 or 39 °C). Despite using relatively low levels of inbreeding significant inbreeding depression was found in pupal mass, pupal time, thorax mass, abdomen fat content, egg hatching success and fecundity. However, stress resistance traits (heat tolerance, immune function) were not affected by inbreeding and interactions with temperature treatments were virtually absent. We thus found no support for an increased sensitivity of inbred individuals to environmental stress, and suspect that such patterns are restricted to harsher conditions. Our temperature treatments evidently imposed stress, significantly reducing longevity, fecundity, egg hatching success and haemocyte numbers, while fat content, protein content and lysozyme activity remained unaffected. Males and females differed in all traits measured except pupal time, protein content and phenoloxidase (PO) activity. Correlation analyses revealed, among others, a trade-off between PO and lysozyme activity, and negative correlations between fat content and several other traits. We stress that more data are needed on the effects of inbreeding, temperature variation and sexual differences on insect immune function before more general conclusions can be drawn. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

Superparasitism, immune response and optimum progeny yield in the gregarious parasitoid Palmistichus elaeisis.

PubMed

de S Pereira, Kleber; Guedes, Nelsa Maria P; Serrão, José E; Zanuncio, José C; Guedes, Raul Narciso C

2017-06-01

The subsequent deposition of an egg clutch by a female parasitoid into a host already parasitised either by itself or a conspecific (i.e. superparasitism) is a counterintuitive adaptive strategy, particularly considering the female parasitoid's ability to recognise the parasitised hosts. Such a scenario suggests that the adaptive value of superparasitism depends on the number of clutches laid in the same host, with consequences for parasitoid progeny yield. Here, we tested whether such is the case for the gregarious parasitoid Palmistichus elaeisis and explored its underlying basis. Allowing female parasitoids to lay multiple egg clutches in a single melonworm host pupa, parasitoid progeny and fitness exhibited a peak or optimum at three egg clutches laid per host pupa. In addition, haemocyte count, encapsulation and melanisation decreased with the number of egg clutches laid per host pupa. An optimum number of three clutches laid per host pupa was detected for P. elaeisis. As immune response via haemocyte production, encapsulation and melanisation decreased with the number of clutches laid per host, the higher parasitoid yield and fitness observed is the likely consequence of a compromised immune response coupled with an accommodative (i.e. scramble) larval competitive strategy allowing enough resources for optimum balance of parasitoid number and quality produced. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Molecular detection of candida species from hospitalized patient’s specimens.

PubMed

Camacho-Cardoso, José Luis; Martínez-Rivera, María Ángeles; Manzano-Gayosso, Patricia; Méndez-Tovar, Luis Javier; López-Martínez, Rubén; Hernández-Hernández, Francisca

To identify the most frequent Candida species in specimens from patients hospitalized in different medical centers of Mexico City, with suspected fungal infection. Specimens were grown on Sabouraud dextrose agar at 28°C for 72 h. In addition, DNA was extracted. Isolates were grown on CHROMagar Candida™, at 37°C for 48 h. The molecular identification was performed by polymerase chain reaction (PCR) using primers specific for four species. Eighty one specimens were processed and included: bronchial lavage, pleural, cerebrospinal, peritoneal, ascites and bile fluids; blood, sputum, bone marrow, oro-tracheal cannula and ganglion. By culture, 30 samples (37%) were positive, and by PCR, 41 (50.6%). By PCR, the frequency of species was: Candida albicans 82.9%, Candida tropicalis 31.7%, Candida glabrata 24.4%, and Candida parapsilosis 4.9%. In 34.1% of specimens a species mixture was detected suggesting a co-infection: Two species in five specimens (C. albicans-C tropicalis and C. albicans-C glabrata), and three species in three specimens (C. albicans-C. glabrata-C. tropicalis). The PCR is an useful tool for detection the most common Candida species causing infection in hospitalized patients, it avoids the requirement of culture weather we start from clinical specimen and it favors the early diagnosis of invasive candidiasis. Copyright: © 2017 SecretarÍa de Salud

Molecular characterization of Candida isolates from intensive care unit patients, Krakow, Poland.

PubMed

Małek, Marianna; Paluchowska, Paulina; Bogusz, Bożena; Budak, Alicja

Over the last decades, Candida species have emerged as important pathogens in immunocompromised patients. Nosocomial infections are mainly of endogenous origin. Nevertheless, some cases of exogenous candidiasis have also been reported. The aim of this study was to evaluate the genetic relatedness between Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei and Candida kefyr isolates recovered from intensive care unit (ICU) patients. A total of 132 Candida clinical isolates (62 C. albicans, 40 C. glabrata, 13 C. tropicalis, 11 C. krusei, 6 C. kefyr), obtained from specimens of endotracheal aspirate, urine and blood taken from patients of a tertiary hospital in Poland, were included in the study. Species identification was performed by PCR method and genetic relatedness was assessed by randomly amplified polymorphic DNA assay (RAPD) with five primers. The RAPD analysis revealed high genetic diversity among the studied Candida isolates, indicating that most of the strains were from endogenous sources. Only two clonal strains of C. glabrata isolated from different patients were observed, suggesting a possible cross-transmission of these pathogens. Our study confirmed the high discriminatory power of the RAPD assay. This genotyping method can be applied to local epidemiological studies of Candida species. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Rapid identification of drug resistant Candida species causing recurrent vulvovaginal candidiasis.

PubMed

Diba, Kambiz; Namaki, Atefeh; Ayatolahi, Haleh; Hanifian, Haleh

2012-01-01

Some yeast agents including Candida albicans, Candida tropicalis and Candida glabrata have a role in recurrent vulvovaginal candidiasis. We studied the frequency of both common and recurrent vulvovaginal candidiasis in symptomatic cases which were referred to Urmia Medical Sciences University related gynecology clinics using morphologic and molecular methods. The aim of this study was the identification of Candida species isolated from recurrent vulvovaginal candidiasis cases using a rapid and reliable molecular method. Vaginal swabs obtained from each case, were cultured on differential media including cornmeal agar and CHROM agar Candida. After 48 hours at 37℃, the cultures were studied for growth characteristics and color production respectively. All isolates were identified using the molecular method of PCR - restriction fragment length polymorphism. Among all clinical specimens, we detected 19 ( 16 % ) non fungal agents, 87 ( 82.1 % ) yeasts and 2 ( 1.9 % ) multiple infections. The yeast isolates identified morphologically included Candida albicans ( n = 62 ), Candida glabrata ( n = 9 ), Candida tropicalis ( n = 8 ), Candida parapsilosis ( n = 8 ) and Candida guilliermondii and Candida krusei ( n = 1 each ). We also obtained very similar results for Candida albicans, Candida glabrata and Candida tropicalis as the most common clinical isolates, by using PCR - Restriction Fragment Length Polymorphism. Use of two differential methods, morphologic and molecular, enabled us to identify most medically important Candida species which particularly cause recurrent vulvovaginal candidiasis.

Epidemiology and antifungal susceptibilities of yeasts causing vulvovaginitis in a teaching hospital.

PubMed

Gamarra, Soledad; Morano, Susana; Dudiuk, Catiana; Mancilla, Estefanía; Nardin, María Elena; de Los Angeles Méndez, Emilce; Garcia-Effron, Guillermo

2014-10-01

Vulvovaginal candidiasis is one of the most common mycosis. However, the information about antifungal susceptibilities of the yeasts causing this infection is scant. We studied 121 yeasts isolated from 118 patients with vulvovaginal candidiasis. The isolates were identified by phenotypic and molecular methods, including four phenotypic methods described to differentiate Candida albicans from C. dubliniensis. Antifungal susceptibility testing was performed according to CLSI documents M27A3 and M27S4 using the drugs available as treatment option in the hospital. Diabetes, any antibacterial and amoxicillin treatment were statistically linked with vulvovaginal candidiasis, while oral contraceptives were not considered a risk factor. Previous azole-based over-the-counter antifungal treatment was statistically associated with non-C.albicans yeasts infections. The most common isolated yeast species was C. albicans (85.2 %) followed by C. glabrata (5 %), Saccharomyces cerevisiae (3.3 %), and C. dubliniensis (2.5 %). Fluconazole- and itraconazole-reduced susceptibility was observed in ten and in only one C. albicans strains, respectively. All the C. glabrata isolates showed low fluconazole MICs. Clotrimazole showed excellent potency against all but seven isolates (three C. glabrata, two S. cerevisiae, one C. albicans and one Picchia anomala). Any of the strains showed nystatin reduced susceptibility. On the other hand, terbinafine was the less potent drug. Antifungal resistance is still a rare phenomenon supporting the use of azole antifungals as empirical treatment of vulvovaginal candidiasis.

Prevalence and Antifungal Susceptibility of 442 Candida Isolates from Blood and Other Normally Sterile Sites: Results of a 2-Year (1996 to 1998) Multicenter Surveillance Study in Quebec, Canada

PubMed Central

St-Germain, G.; Laverdière, M.; Pelletier, R.; Bourgault, A.-M.; Libman, M.; Lemieux, C.; Noël, G.

2001-01-01

During a 2-year surveillance program (1996 to 1998) in Quebec, Canada, 442 strains of Candida species were isolated from 415 patients in 51 hospitals. The distribution of species was as follows: Candida albicans, 54%; C. glabrata, 15%; C. parapsilosis, 12%; C. tropicalis, 9%; C. lusitaniae, 3%; C. krusei, 3%; and Candida spp., 3%. These data, compared to those of a 1985 survey, indicate variations in species distribution, with the proportions of C. glabrata and C. parapsilosis increasing by 9 and 4%, respectively, and those of C. albicans and C. tropicalis decreasing by 10 and 7%, respectively. However, these differences are statistically significant for C. glabrata and C. tropicalis only. MICs of amphotericin B were ≥4 μg/ml for 3% of isolates, all of which were non-C. albicans species. Three percent of C. albicans isolates were resistant to flucytosine (≥32 μg/ml). Resistance to itraconazole (≥1 μg/ml) and fluconazole (≥64 μg/ml) was observed, respectively, in 1 and 1% of C. albicans, 14 and 9% of C. glabrata, 5 and 0% of C. tropicalis, and 0% of C. parapsilosis and C. lusitaniae isolates. Clinical data were obtained for 343 patients. The overall crude mortality rate was 38%, reflecting the multiple serious underlying illnesses found in these patients. Bloodstream infections were documented for 249 patients (73%). Overall, systemic triazoles had been administered to 10% of patients before the onset of candidiasis. The frequency of isolation of non-C. albicans species was significantly higher in this group of patients. Overall, only two C. albicans isolates were found to be resistant to fluconazole. These were obtained from an AIDS patient and a leukemia patient, both of whom had a history of previous exposure to fluconazole. At present, it appears that resistance to fluconazole in Quebec is rare and is restricted to patients with prior prolonged azole treatment. PMID:11230409

Comparative Analysis between Ecotoxicity of Nitrogen-, Phosphorus-, and Potassium-Based Fertilizers and Their Active Ingredients

PubMed Central

Simplício, Nathan de Castro Soares; Muniz, Daphne Heloísa de Freitas; Rocha, Fernanda Regina Moreira; Martins, Denis Cavalcanti; Dias, Zélia Malena Barreira; Farias, Bruno Pereira da Costa; Oliveira-Filho, Eduardo Cyrino

2016-01-01

This study aimed to analyze the ecotoxicity of nitrogen-, phosphorus-, and potassium-based compounds to organisms of two different trophic levels in order to compare the toxic effect between high-purity substances and these substances as components of fertilizers. Dilutions were made with the fertilizers’ potassium chloride, potassium nitrate, superphosphate, urea, and their equivalent reagents, to conduct assays to establish the acute lethal concentration for half of the population (LC50). Ten individuals of the benthic snail Biomphalaria glabrata and the fish Danio rerio were exposed to each concentration of tested compounds. As a result, the toxicity levels of potassium chloride, potassium nitrate, and urea were obtained for B. glabrata and D. rerio, with the fish being more susceptible to potassium chloride in the fertilizer and the snail to potassium nitrate and urea, in both commercial and reagent forms. Regarding superphosphate, no significant toxicity was found. This study concluded that among the tested substances, KNO3 and KCl were the most toxic substances and urea the least toxic. It was not possible to establish the most sensitive species since, for KCl, the fish were more susceptible to the fertilizer and the snail to the reagent, while for KNO3 the opposite was observed. PMID:29051434

[Comparison of methods for the identification of the most common yeasts in the clinical microbiology laboratory].

PubMed

Guelfand, L; Grisolía, P; Bozzano, C; Kaufman, S

2003-01-01

We evaluated different methods for the routine identification of medically important yeasts. A total of 150 clinical isolates: 25 C. albicans, 25 C. tropicalis, 25 C. glabrata, 25 C. parapsilosis, 8 C. guilliermondii, 11 C. krusei and 31 Cryptococcus neoformans were tested by Yeast Biochemical Card bioMerieux Vitek (YBC), CHROMagar Candida (CHR). The addition of yeast morphology in Corn Meal agar-Tween 80 (AM) to YBC and CHR was also evaluated. The reference methods used were: API 20C, germ tube formation, AM, Christensen urea and Birdseed agar. YBC identified 135 yeasts with an overall accuracy of 90%. Sensitivity (S) and specificity (E) were: 92-98% for C. albicans and C. tropicalis; 84-99% for C. papapsilosis; 100-99% for C. glabrata; 91-100% for C. krusei; 63-98% for C. guilliermondii and 90-99% for Cryptococcus neoformans, respectively. CHR identified correctly 100% for C. albicans, 92% for C. tropicalis and 91% for C. krusei. Both methods combined with AM provided 100% S and E. We found that YBC system was appropriate for identification of yeasts isolated from human sources. CHR was effective and easy to use for identification of C. albicans, C. tropicalis and C. krusei. The routine use of AM with both methods is recommended.

Transcriptome analysis of Schistosoma mansoni larval development using serial analysis of gene expression (SAGE).

PubMed

Taft, A S; Vermeire, J J; Bernier, J; Birkeland, S R; Cipriano, M J; Papa, A R; McArthur, A G; Yoshino, T P

2009-04-01

Infection of the snail, Biomphalaria glabrata, by the free-swimming miracidial stage of the human blood fluke, Schistosoma mansoni, and its subsequent development to the parasitic sporocyst stage is critical to establishment of viable infections and continued human transmission. We performed a genome-wide expression analysis of the S. mansoni miracidia and developing sporocyst using Long Serial Analysis of Gene Expression (LongSAGE). Five cDNA libraries were constructed from miracidia and in vitro cultured 6- and 20-day-old sporocysts maintained in sporocyst medium (SM) or in SM conditioned by previous cultivation with cells of the B. glabrata embryonic (Bge) cell line. We generated 21 440 SAGE tags and mapped 13 381 to the S. mansoni gene predictions (v4.0e) either by estimating theoretical 3' UTR lengths or using existing 3' EST sequence data. Overall, 432 transcripts were found to be differentially expressed amongst all 5 libraries. In total, 172 tags were differentially expressed between miracidia and 6-day conditioned sporocysts and 152 were differentially expressed between miracidia and 6-day unconditioned sporocysts. In addition, 53 and 45 tags, respectively, were differentially expressed in 6-day and 20-day cultured sporocysts, due to the effects of exposure to Bge cell-conditioned medium.

Spatial distribution and seasonality of Biomphalaria spp. in São Luís (Maranhão, Brazil).

PubMed

David, Nathalia Ferreira; Cantanhede, Selma Patrícia Diniz; Monroe, Natanael Bezerra; Pereira, Luciana Patrícia Lima Alves; Silva-Souza, Nêuton; Abreu-Silva, Ana Lúcia; de Oliveira, Verônica Maria; Tchaicka, Ligia

2018-05-01

Two of the three vector species of Schistosoma mansoni Sambon, 1907 in Brazil occur in the state of Maranhão: Biomphalaria glabrata (Say, 1818) and Biomphalaria straminea (Dunker, 1848). For the implementation of effective measures to combat schistosomiasis, it is necessary to identify the spatial and seasonal dynamics of these snails. Therefore, this work brought together information from malacological survey carried out in São Luís (Maranhão, Brazil) to identify the spatial and seasonal distribution patterns of Biomphalaria spp. snails. We used data from malacological surveys of the Municipal Health Secretary of São Luís, conducted between 2006 and 2013 in 23 neighborhoods. We also used data from the mollusk surveys that we conducted for 2 years (2012-2014) in four of these neighborhoods. During the 8-year period (2006-2013), 15,990 specimens of Biomphalaria spp. were collected. There was a positive association between precipitation and the abundance of mollusks of the genus Biomphalaria. During 2012-2014, a total of 2487 snail specimens were obtained (B. glabrata: 1046 specimens; B. straminea: 1426 specimens). There was a positive correlation between precipitation and B. straminea abundance. High density of human occupation and high precipitation are two factors that affect the distribution and density of Biomphalaria spp.

Epidemiology and antifungal susceptibilities of yeast isolates causing invasive infections across urban Beijing, China.

PubMed

Guo, Li-Na; Xiao, Meng; Cao, Bin; Qu, Fen; Zhan, Yu-Liang; Hu, Yun-Jian; Wang, Xin-Ru; Liang, Guo-Wei; Gu, Hai-Tong; Qi, Jun; Yuan, Hui; Min, Rong; Wang, Fei-Yan; Liu, Lin-Juan; Wang, Hai-Bin; Jiang, Wei; Duan, Xue-Guang; Xu, Wen-Jian; Yu, Yan-Hua; Su, Jian-Rong; Zhang, Jian-Zhong; Nong, Jin-Qing; Liu, Shu-Mei; Li, Jun; Liu, Jun-Ting; Yue, Zhi-Gang; Yang, Duo; Guo, Jie; Zhao, Rui; Zhang, Ya-Nan; Yang, Xi-Ming; Liu, Xiao-Qing; Hsueh, Po-Ren; Xu, Ying-Chun

2017-09-01

To investigate the species distribution and antifungal susceptibility profiles of yeast isolates causing invasive infections across Beijing. A total of 1201 yeast isolates recovered from blood and other sterile body fluids were correctly identified by matrix-assisted laser desorption/ionization TOF MS supplemented by DNA sequencing. Antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute broth microdilution method. Candida (95.5%) remained the most common yeast species isolated; Candida albicans (38.8%) and Candida parapsilosis (22.6%) were the leading species of candidemia. Azole resistances were mainly observed in Candida glabrata and Candida tropicalis isolates. This study outlined the epidemiologic data of invasive yeast infections and highlighted the need for continuous monitoring of azole resistances among C. glabrata and C. tropicalis isolates in Beijing.

Antifungal activity of Malaysian honey and propolis extracts against pathogens implicated in denture stomatitis

NASA Astrophysics Data System (ADS)

Yusoff, Nik Yusliyana Nik; Mohamad, Suharni; Abdullah, Haswati@Nurhayati; Rahman, Nurhayu Ab

2016-12-01

Malaysian honey and propolis extracts were investigated for their antifungal properties against pathogens implicated in denture stomatitis. Each of the honey and aqueous extracts propolis at net preparation, 1:1 and 1:2 dilutions was evaluated by using agar well diffusion assay and further investigated by minimum inhibitory concentration (MIC) within the range of 500 mg/mL to 62.5 mg/mL against oral fungi. The findings indicated that there was no effect of propolis on Candida spp for both types of propolis based on no inhibition zones was recorded. Meanwhile, for antifungal activity of honey, only honey from Trigona spp has shown activity at net preparation against C. albicans (10.47 ± 0.23 mm), C. tropicalis (12.29 ± 0.23 mm) and C. glabrata (8.69 ± 0.53 mm). For minimum inhibitory concentration, the data indicates that both propolis have shown inhibitory effect at 500 mg/mL. As for honey, Trigona spp was the effective honey that give MIC value at 250 mg/mL against Candida spp. Apis dorsata honey has shown MIC value at 500 mg/mL while Apis mellifera honey had inhibited C.albicans and C.glabrata at 500 mg/mL except for C.tropicalis at 250 mg/mL. It can be concluded that both propolis has shown weaker antifungal activity against oral fungi while only honey produced from Trigona spp had strong antifungal activity compare to other honey against oral fungi implicated in denture stomatitis.

Influence of Culture Media on Biofilm Formation by Candida Species and Response of Sessile Cells to Antifungals and Oxidative Stress

PubMed Central

Serrano-Fujarte, Isela; Reyna-López, Georgina Elena; Martínez-Gámez, Ma. Alejandrina; Vega-González, Arturo; Cuéllar-Cruz, Mayra

2015-01-01

The aims of the study were to evaluate the influence of culture media on biofilm formation by C. albicans, C. glabrata, C. krusei, and C. parapsilosis and to investigate the responses of sessile cells to antifungals and reactive oxygen species (ROS) as compared to planktonic cells. For biofilm formation, the Candida species were grown at different periods of time in YP or YNB media supplemented or not with 0.2 or 2% glucose. Sessile and planktonic cells were exposed to increasing concentrations of antifungals, H2O2, menadione or silver nanoparticles (AgNPs). Biofilms were observed by scanning electron microscopy (SEM) and quantified by the XTT assay. C. albicans formed biofilms preferentially in YPD containing 2% glucose (YPD/2%), C. glabrata in glucose-free YNB or supplemented with 0.2% glucose (YNB/0.2%), while C. krusei and C. parapsilosis preferred YP, YPD/0.2%, and YPD/2%. Interestingly, only C. albicans produced an exopolymeric matrix. This is the first report dealing with the in vitro effect of the culture medium and glucose on the formation of biofilms in four Candida species as well as the resistance of sessile cells to antifungals, AgNPs, and ROS. Our results suggest that candidiasis in vivo is a multifactorial and complex process where the nutritional conditions, the human immune system, and the adaptability of the pathogen should be considered altogether to provide an effective treatment of the patient. PMID:25705688

In Vitro Assessment of the Antimicrobial Efficacy of Optimized Nitroglycerin-Citrate-Ethanol as a Nonantibiotic, Antimicrobial Catheter Lock Solution for Prevention of Central Line-Associated Bloodstream Infections.

PubMed

Reitzel, Ruth A; Rosenblatt, Joel; Hirsh-Ginsberg, Cheryl; Murray, Kimberly; Chaftari, Anne-Marie; Hachem, Ray; Raad, Issam

2016-09-01

The rapid, broad-spectrum, biofilm-eradicating activity of the combination of 0.01% nitroglycerin, 7% citrate, and 20% ethanol and its potential as a nonantibiotic, antimicrobial catheter lock solution (ACLS) were previously reported. Here, a nitroglycerin-citrate-ethanol (NiCE) ACLS optimized for clinical assessment was developed by reducing the nitroglycerin and citrate concentrations and increasing the ethanol concentration. Biofilm-eradicating activity was sustained when the ethanol concentration was increased from 20 to 22% which fully compensated for reducing the citrate concentration from 7% to 4% as well as the nitroglycerin concentration from 0.01% to 0.0015% or 0.003%. The optimized formulations demonstrated complete and rapid (2 h) eradication of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate Staphylococcus aureus (VISA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant enterococci (VRE), multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Klebsiella pneumoniae, MDR Enterobacter cloacae, MDR Acinetobacter baumannii, MDR Escherichia coli, MDR Stenotrophomonas maltophilia, Candida albicans, and Candida glabrata biofilms. The optimized NiCE lock solutions demonstrated anticoagulant activities comparable to those of heparin lock solutions. NiCE lock solution was significantly more effective than taurolidine-citrate-heparin lock solution in eradicating biofilms of Staphylococcus aureus and Candida glabrata The optimized, nonantibiotic, heparin-free NiCE lock solution demonstrates rapid broad-spectrum biofilm eradication as well as effective anticoagulant activity, making NiCE a high-quality ACLS candidate for clinical assessment. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Influence of culture media on biofilm formation by Candida species and response of sessile cells to antifungals and oxidative stress.

PubMed

Serrano-Fujarte, Isela; López-Romero, Everardo; Reyna-López, Georgina Elena; Martínez-Gámez, Ma Alejandrina; Vega-González, Arturo; Cuéllar-Cruz, Mayra

2015-01-01

The aims of the study were to evaluate the influence of culture media on biofilm formation by C. albicans, C. glabrata, C. krusei, and C. parapsilosis and to investigate the responses of sessile cells to antifungals and reactive oxygen species (ROS) as compared to planktonic cells. For biofilm formation, the Candida species were grown at different periods of time in YP or YNB media supplemented or not with 0.2 or 2% glucose. Sessile and planktonic cells were exposed to increasing concentrations of antifungals, H2O2, menadione or silver nanoparticles (AgNPs). Biofilms were observed by scanning electron microscopy (SEM) and quantified by the XTT assay. C. albicans formed biofilms preferentially in YPD containing 2% glucose (YPD/2%), C. glabrata in glucose-free YNB or supplemented with 0.2% glucose (YNB/0.2%), while C. krusei and C. parapsilosis preferred YP, YPD/0.2%, and YPD/2%. Interestingly, only C. albicans produced an exopolymeric matrix. This is the first report dealing with the in vitro effect of the culture medium and glucose on the formation of biofilms in four Candida species as well as the resistance of sessile cells to antifungals, AgNPs, and ROS. Our results suggest that candidiasis in vivo is a multifactorial and complex process where the nutritional conditions, the human immune system, and the adaptability of the pathogen should be considered altogether to provide an effective treatment of the patient.

Evaluation of chromogenic media and seminested PCR in the identification of Candida species

PubMed Central

Daef, Enas; Moharram, Ahmed; Eldin, Salwa Seif; Elsherbiny, Nahla; Mohammed, Mona

2014-01-01

Identification of Candida cultured from various clinical specimens to the species level is increasingly necessary for clinical laboratories. Although sn PCR identifies the species within hours but its cost-effectiveness is to be considered. So there is always a need for media which help in the isolation and identification at the species level. The study aimed to evaluate the performance of different chromogenic media and to compare the effectiveness of the traditional phenotypic methods vs. seminested polymerase chain reaction (sn PCR) for identification of Candida species. One hundred and twenty seven Candida strains isolated from various clinical specimens were identified by conventional methods, four different chromogenic media and sn PCR. HiCrome Candida Differential and CHROMagar Candida media showed comparably high sensitivities and specificities in the identification of C. albicans, C. tropicalis, C. glabrata and C. krusei. CHROMagar Candida had an extra advantage of identifying all C. parapsilosis isolates. CHROMagar-Pal’s medium identified C. albicans, C. tropicalis and C. krusei with high sensitivities and specificities, but couldn’t identify C. glabrata or C. parapsilosis. It was the only medium that identified C. dubliniensis with a sensitivity and specificity of 100%. Biggy agar showed the least sensitivities and specificities. The overall concordance of the snPCR compared to the conventional tests including CHROMAgar Candida in the identification of Candida species was 97.5%. The use of CHROMAgar Candida medium is an easy and accurate method for presumptive identification of the most commonly encountered Candida spp. PMID:24948942

Antifungal Susceptibility Testing in HIV/AIDS Patients: a Comparison Between Automated Machine and Manual Method.

PubMed

Nelwan, Erni J; Indrasanti, Evi; Sinto, Robert; Nurchaida, Farida; Sosrosumihardjo, Rustadi

2016-01-01

to evaluate the performance of Vitek2 compact machine (Biomerieux Inc. ver 04.02, France) in reference to manual methods for susceptibility test for Candida resistance among HIV/AIDS patients. a comparison study to evaluate Vitek2 compact machine (Biomerieux Inc. ver 04.02, France) in reference to manual methods for susceptibility test for Candida resistance among HIV/AIDS patient was done. Categorical agreement between manual disc diffusion and Vitek2 machine was calculated using predefined criteria. Time to susceptibility result for automated and manual methods were measured. there were 137 Candida isolates comprising eight Candida species with C.albicans and C. glabrata as the first (56.2%) and second (15.3%) most common species, respectively. For fluconazole drug, among the C. albicans, 2.6% was found resistant on manual disc diffusion methods and no resistant was determined by Vitek2 machine; whereas 100% C. krusei was identified as resistant on both methods. Resistant patterns for C. glabrata to fluconazole, voriconazole and amphotericin B were 52.4%, 23.8%, 23.8% vs. 9.5%, 9.5%, 4.8% respectively between manual diffusion disc methods and Vitek2 machine. Time to susceptibility result for automated methods compared to Vitex2 machine was shorter for all Candida species. there is a good categorical agreement between manual disc diffusion and Vitek2 machine, except for C. glabrata for measuring the antifungal resistant. Time to susceptibility result for automated methods is shorter for all Candida species.

Warthin tumor presenting as a fungal abscess in an immunocompetent host: case report and review of the literature.

PubMed

Leibowitz, Jason M; Montone, Kathleen T; Basu, Devraj

2010-01-01

Fungal abscesses of the parotid gland are rare, and cases arising within parotid neoplasms have not been described previously. This report conveys our experience managing such an entity, which is further distinguished by its occurrence in an immunocompetent host. A 59-year-old man experienced multiple recurrences of a parotid fungal abscess requiring repeated drainage procedures. Definitive excision ultimately demonstrated Candida glabrata infecting a Warthin tumor. This case is the first report of a parotid neoplasm presenting as a fungal abscess. It contributes to the scant literature on fungal abscesses of the parotid, which previously has only been described in debilitated hosts and without an associated neoplasm. The case also expands the spectrum of disease associated with C. glabrata. Warthin tumor may be an occult etiology for a parotid fungal abscess, and definitive diagnosis and therapy may require parotidectomy.

Integrated multi-omic analyses in Biomphalaria-Schistosoma dialogue reveal the immunobiological significance of FREP-SmPoMuc interaction.

PubMed

Portet, Anaïs; Pinaud, Silvain; Tetreau, Guillaume; Galinier, Richard; Cosseau, Céline; Duval, David; Grunau, Christoph; Mitta, Guillaume; Gourbal, Benjamin

2017-10-01

The fresh water snail Biomphalaria glabrata is one of the vectors of the trematode pathogen Schistosoma mansoni, which is one of the agents responsible of human schistosomiasis. In this host-parasite interaction, co-evolutionary dynamic results into an infectivity mosaic known as compatibility polymorphism. Integrative approaches including large scale molecular approaches have been conducted in recent years to improve our understanding of the mechanisms underlying compatibility. This review presents the combination of integrated Multi-Omic approaches leading to the discovery of two repertoires of polymorphic and/or diversified interacting molecules: the parasite antigens S. mansoni polymorphic mucins (SmPoMucs) and the B. glabrata immune receptors fibrinogen-related proteins (FREPs). We argue that their interactions may be major components for defining the compatible/incompatible status of a specific snail/schistosome combination. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isoterchebulin and 4,6-O-isoterchebuloyl-D-glucose, novel hydrolyzable tannins from Terminalia macroptera.

PubMed

Conrad, J; Vogler, B; Reeb, S; Klaiber, I; Papajewski, S; Roos, G; Vasquez, E; Setzer, M C; Kraus, W

2001-03-01

Two new hydrolyzable tannins, isoterchebulin (1) and 4,6-O-isoterchebuloyl-D-glucose (2), together with six known tannins, 3-8, were isolated from the bark of Terminalia macroptera. Their structures were elucidated by extensive 1D and 2D NMR studies, MS, and chemical transformations. Biological activities of all compounds were evaluated against the snail Biomphalaria glabrata, the bacteria Bacillus subtilis and Pseudomonas fluorescens, the nematode Caenorhabditis elegans, and four cancer cell lines (Hep G2, MCF-7/S, MDA-MB-231, and 5637 cells). All compounds except 3 showed antimicrobial activities against B. subtilis (MIC 8-64 microg/mL), whereas only 1 was active against C. elegans (100 microg/mL) and B. glabrata(LC(100) = 60 microg/mL). 3 and 8 were toxic against 5637 cells with LC(50) = 84.66 and 41.40 microM, respectively.

Hichrom candida agar for identification of Candida species.

PubMed

Baradkar, V P; Mathur, M; Kumar, S

2010-01-01

Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore formation on tobacco agar and sugar assimilation tests. The sensitivity and specificity results were: C. albicans (96.55 and 96.42%); C. parapsilosis (80 and 98.03%), C. glabrata (90.90 and 88.23%), C. tropicalis (100 and 100%) and C. dubliniensis (60 and 96.55%) respectively. HiChrom Candida agaris medium has been useful and capable of presumptive, rapid identification of Candida species within 48 hours.

Quantitative genetics of immunity and life history under different photoperiods.

PubMed

Hammerschmidt, K; Deines, P; Wilson, A J; Rolff, J

2012-05-01

Insects with complex life-cycles should optimize age and size at maturity during larval development. When inhabiting seasonal environments, organisms have limited reproductive periods and face fundamental decisions: individuals that reach maturity late in season have to either reproduce at a small size or increase their growth rates. Increasing growth rates is costly in insects because of higher juvenile mortality, decreased adult survival or increased susceptibility to parasitism by bacteria and viruses via compromised immune function. Environmental changes such as seasonality can also alter the quantitative genetic architecture. Here, we explore the quantitative genetics of life history and immunity traits under two experimentally induced seasonal environments in the cricket Gryllus bimaculatus. Seasonality affected the life history but not the immune phenotypes. Individuals under decreasing day length developed slower and grew to a bigger size. We found ample additive genetic variance and heritability for components of immunity (haemocyte densities, proPhenoloxidase activity, resistance against Serratia marcescens), and for the life history traits, age and size at maturity. Despite genetic covariance among traits, the structure of G was inconsistent with genetically based trade-off between life history and immune traits (for example, a strong positive genetic correlation between growth rate and haemocyte density was estimated). However, conditional evolvabilities support the idea that genetic covariance structure limits the capacity of individual traits to evolve independently. We found no evidence for G × E interactions arising from the experimentally induced seasonality.

EVALUATION OF A RAPID, QUANTITATIVE REAL-TIME PCR METHOD FOR ENUMERATION OF PATHOGENIC CANDIDA CELLS IN WATER

EPA Science Inventory

Quantitative Real-Time PCR (QRT-PCR) technology, incorporating fluorigenic 5' nuclease (TaqMan?) chemistry, was developed for the specific detection and quantification of six pathogenic species of Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis, C. glabrata and C....

Comparison of enzymatic activities in different Candida species isolated from women with vulvovaginitis.

PubMed

Fatahinia, M; Halvaeezadeh, M; Rezaei-Matehkolaei, A

2017-06-01

Comparing the activities of secreted enzymes in different fungal species can improve our understanding of their pathogenic role. Secretion of various enzymes by Candida species has been considered for determination of their virulence in different Candida infections including vulvovaginitis. The aim of this study was to determine and compare the activity of secreted enzymes in Candidia strains isolated from women suspected to vulvovaginal candidiasis (VVC) and referred to some health centers in Khuzestan, Southwestern Iran. The vaginal secretion samples were taken by swap from 250 suspected women with symptoms of vulvovaginal candidiasis and cultured on CHROMagar Candida medium. Identification of the isolated Candida from culture positive samples performed by the color of colonies and some standard mycological procedures. Activities of phospholipase, hemolysin-α, hemolysin-β, esterase and proteinase were measured in vitro by standard laboratory protocols. The enzymatic activity index (EAI) was calculated for each enzyme in accordance to relevant protocols. Totally in eighty cases (32%), a Candida strain was isolated which found to be as 52 (65%) Candida albicans; 12 (15%) C. glabrata; 10 (12.5%) C. dubliniensis; 4 (5%) C. krusei, C. tropicalis and C. parapsilosis species (each=1; 1.3%). Among C. albicans strains, 89.1% produced all studied enzymes, while 86% of C. glabrata strains failed to produce proteinase and phospholipase. The EAIs in decreasing order were as hemolysin-β=0.2895, hemolysin-α=0.5420, esterase=0.5753, proteinase=0.7413, and phospholipase=0.7446, respectively. Activity of phospholipase, esterase and proteinase secreted by C. albicans and C. dubliniensis were significantly more than those released by C. glabrata and C. krusei, while 86% of C. glabrata strains did not show esterase activity. On the other hand, the activity rates of hemolysin α and β among all studied isolates were almost similar. In the present study, the prevalence

Fungal Profile of Vulvovaginal Candidiasis in a Tertiary Care Hospital.

PubMed

Kalaiarasan, Krishnapriya; Singh, Rakesh; Chaturvedula, Latha

2017-03-01

Vulvovaginal Candidiasis (VVC) is a common medical health problem of adult women. It is most commonly caused by Candida albicans . But there is a change in fungal profile. Sabouraud's Dextrose Agar (SDA) is the most common culture medium used where mixed fungal infection may be missed. It can be detected easily by using chromogenic culture medium. To know the fungal profile of vulvovaginal candidiasis using Candida CHROMagar and antifungal susceptibility pattern in patients attending tertiary care hospital. Culture confirmed cases of VVC presented at Department of Obstetrics and Gynaecology of Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India, from July 2015 to December 2015 were included in the cross-sectional study. Two high vaginal swabs were collected and inoculated on SDA and Candida CHROMagar (Hi-Media, Mumbai, India). After overnight incubation the colonies were counted and colour of the colonies were recorded from Candida CHROMagar. Candida spp. were identified by sugar fermentation and assimilation tests and other conventional tests. Antifungal susceptibility tests were performed by the disc diffusion method using fluconazole (25 μg) and voriconazole (1μg) as per the Clinical and Laboratory Standards Institute (CLSI - M44-A2) guidelines. A total of 50 culture confirmed (23.7%) cases were detected from 211 clinically suspected VVC cases. Candida glabrata (45.1%) was the most common isolate, followed by Candida tropicalis (23.5%) , Candida albicans (17.6%) , Candida krusei (9.8%) and Candida parapsilosis (3.9%) . One mixed infection of C. glabrata and C. albicans was identified on Candida CHROMagar. Mixed fungal infection was observed in 2% of positive culture and 0.5% of VVC cases. The antifungal susceptibility testing revealed that 15.7% and 9.8% isolates of Candida spp. were resistant and Susceptible Dose Dependent (S-DD) respectively to fluconazole. The increase resistant against fluconazole was because of

Mixtures of tritiated water, zinc and dissolved organic carbon: Assessing interactive bioaccumulation and genotoxic effects in marine mussels, Mytilus galloprovincialis.

PubMed

Pearson, Holly B C; Dallas, Lorna J; Comber, Sean D W; Braungardt, Charlotte B; Worsfold, Paul J; Jha, Awadhesh N

2018-07-01

Release of tritium ( 3 H) in the marine environment is of concern with respect to its potential bioaccumulation and detrimental impact on the biota. Previous studies have investigated the uptake and toxicity of this radionuclide in marine mussels, and the interaction of 3 H with dissolved organic ligands and elevated temperature. However, despite the well-established view that toxicity is partly governed by chemical speciation, and that toxic effects of mixture of contaminants are not always additive, there have been no studies linking the prevailing chemistry of exposure waters with observed biological effects and tissue specific accumulation of 3 H in combination with other constituents commonly found in natural waters. This study exposed the marine mussel Mytilus galloprovincialis for 14 days to mixtures of 3 H (as tritiated water, HTO) and zinc (Zn) at 5 Mbq L -1 , and 383, 1913 and 3825 nM Zn, respectively, to investigate (a) 3 H and Zn partitioning in soft tissues of mussels, and (b) DNA damage in haemocytes, determined using the single cell gel electrophoresis or the comet assay. Additionally, the extent of association of 3 H with dissolved organic carbon (DOC, added as humic acid) over the exposure period was investigated in order to aid the interpretation of biological uptake and effects. Results concluded a clear antagonistic effect of Zn on 3 H-induced DNA damage at all Zn concentrations used, likely explained by the importance of Zn in DNA repair enzymes. The interaction of DOC with 3 H was variable, with strong 3 H-DOC associations observed in the first 3 d of the experiment. The secretion of 3 H-binding ligands by the mussels is suggested as a possible mechanism for early biological control of 3 H toxicity. The results suggest risk assessments for radionuclides in the environment require consideration of potential mixture effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Debaryomyces hansenii: A Model System for Marine Molecular Biology

DTIC Science & Technology

1991-12-31

Gajadhar et al. 1991), Plasmodium berghei (Gunderson et al. 1986), Oytricha nova (Elwood et al. 1985), Paramecium terraurelia (Sogin and Elwood, 1986...berg J𔃾 Paramecium tenaurelia Dyctelioniiw discoideum 0.1 II -ifTorzdospra delbrueckii 52 Can&&d glabrata Saccharomyces cerevisiae 98 Kluyveromyces

In vitro synergism between berberine and miconazole against planktonic and biofilm Candida cultures.

PubMed

Wei, Guo-Xian; Xu, Xin; Wu, Christine D

2011-06-01

To investigate the antimycotic activity of the plant alkaloid berberine (BBR), alone and in combination with antifungal azoles, against planktonic and biofilm Candida cultures. The minimum inhibitory concentrations (MICs) of BBR, miconazole (MCZ), and fluconazole (FLC) towards Candida albicans, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis, and Candida tropicalis were determined by a microdilution method. For C. albicans, the synergistic effects of BBR combined with MCZ or FLC were examined in a paper disc agar diffusion assay and checkerboard microdilution assay. The effect of the BBR/MCZ combination was further investigated in a C. albicans biofilm formation model with a dual-chamber flow cell. The effect on metabolic activity of biofilm cells was established using 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)/menadione. Berberine inhibited the growth of various Candida species (MICs 0.98-31.25mg/L) in the following order of susceptibility: C. krusei > C. kefyr > C. glabrata > C. tropicalis > C. parapsilosis and C. albicans. Synergism between BBR and MCZ or FLC was observed in the disc diffusion assay as well as in suspension showing an FIC index <0.5 (∑FIC=0.19). Whilst neither BBR (16 mg/L) nor MCZ (0.8 mg/L) alone significantly inhibited biofilm formation of C. albicans, their combination reduced biofilm formation by >91% after 24 h, as established from the reduction in surface area coverage (P<0.01). The BBR/MCZ combination also exhibited synergy against the metabolic activity of pre-formed C. albicans biofilms in polystyrene microtiter plates (∑FIC=0.25). Berberine exhibits synergistic effects with commonly used antimycotic drugs against C. albicans, either in planktonic or in biofilm growth phases. Published by Elsevier Ltd.

[National Trends in the Distribution of Candida Species Causing Candidemia in Japan from 2003 to 2014].

PubMed

Kakeya, Hiroshi; Yamada, Koichi; Kaneko, Yukihiro; Yanagihara, Katsunori; Tateda, Kazuhiro; Maesaki, Shigefumi; Takesue, Yoshio; Tomono, Kazunori; Kadota, Jun-Ichi; Kaku, Mitsuo; Miyazaki, Yoshitsugu; Kamei, Katsuhiko; Shibuya, Kazutoshi; Niki, Yoshitiho; Yoshida, Minoru; Sei, Yoshihiro

2018-01-01

The Epidemiological Investigation Committee for Human Mycoses in Japan performed a retrospective epidemiological survey of candidemia and causative Candida species. Data from 2003 to 2014 were collected from 10 Japanese university hospitals. A total of 328,318 blood cultures were included. The prevalence of fungi in all cultures and in positive cultures were 0.58±0.09% and 4.46±0.66%, respectively. Among the results that were positive for Candida species (N=1,921), Candida albicans was the most common species (39.5%) and was followed by Candida parapsilosis (23.3%), Candida glabrata (13.2%), Candida tropicalis (7.1%), Candida krusei (3.2%), and others (13.7%). During the last 6 years, the frequency of C. albicans has significantly decreased in Japan, while that of C. glabrata has increased. Additional surveys are needed to continuously monitor the trends in the distribution of candidemia.

Evolutionary relationships among pathogenic Candida species and relatives.

PubMed Central

Barns, S M; Lane, D J; Sogin, M L; Bibeau, C; Weisburg, W G

1991-01-01

Small subunit rRNA sequences have been determined for 10 of the most clinically important pathogenic species of the yeast genus Candida (including Torulopsis [Candida] glabrata and Yarrowia [Candida] lipolytica) and for Hansenula polymorpha. Phylogenetic analyses of these sequences and those of Saccharomyces cerevisiae, Kluyveromyces marxianus var. lactis, and Aspergillus fumigatus indicate that Candida albicans, C. tropicalis, C. parapsilosis, and C. viswanathii form a subgroup within the genus. The remaining significant pathogen, T. glabrata, falls into a second, distinct subgroup and is specifically related to S. cerevisiae and more distantly related to C. kefyr (psuedotropicalis) and K. marxianus var. lactis. The 18S rRNA sequence of Y. lipolytica has evolved rapidly in relation to the other Candida sequences examined and appears to be only distantly related to them. As anticipated, species of several other genera appear to bear specific relationships to members of the genus Candida. PMID:2007550

Liquid and vapour-phase antifungal activities of essential oils against Candida albicans and non-albicans Candida.

PubMed

Mandras, Narcisa; Nostro, Antonia; Roana, Janira; Scalas, Daniela; Banche, Giuliana; Ghisetti, Valeria; Del Re, Simonetta; Fucale, Giacomo; Cuffini, Anna Maria; Tullio, Vivian

2016-08-30

The management of Candida infections faces many problems, such as a limited number of antifungal drugs, toxicity, resistance of Candida to commonly antifungal drugs, relapse of Candida infections, and the high cost of antifungal drugs. Though azole antifungal agents and derivatives continue to dominate as drugs of choice against Candida infections, there are many available data referring to the anticandidal activity of essential oils. Since we have previous observed a good antimicrobial activity of some essential oils against filamentous fungi, the aim of this study was to extend the research to evaluate the activity of the same oils on Candida albicans, C.glabrata and C.tropicalis clinical strains, as well as the effects of related components. Essential oils selection was based both on ethnomedicinal use and on proved antibacterial and/or antifungal activity of some of these oils. Fluconazole and voriconazole were used as reference drugs. The minimum inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) of essential oils (thyme red, fennel, clove, pine, sage, lemon balm, and lavender) and their major components were investigated by the broth microdilution method (BM) and the vapour contact assay (VC). Using BM, pine oil showed the best activity against all strains tested, though C.albicans was more susceptible than C.glabrata and C.tropicalis (MIC50-MIC90 = 0.06 %, v/v). On the contrary, sage oil displayed a weak activity (MIC50-MIC90 = 1 %, v/v). Thyme red oil (MIC50-MIC90 ≤ 0.0038 %, v/v for C.albicans and C.tropicalis, and 0.0078- < 0.015 %, v/v for C.glabrata), followed by lemon balm, lavender and sage were the most effective by VC. Carvacrol and thymol showed the highest activity, whereas linalyl acetate showed the lowest activity both by two methods. α-pinene displayed a better activity by BM than VC. Results show a good activity of essential oils, mainly thymus red and pine oils, and their components carvacrol

Identification of an anti-lipopolysacchride factor possessing both antiviral and antibacterial activity from the red claw crayfish Cherax quadricarinatus.

PubMed

Lin, Feng-Yu; Gao, Yan; Wang, Hao; Zhang, Qiu-Xia; Zeng, Chang-Lin; Liu, Hai-Peng

2016-10-01

It is well-known that anti-lipopolysacchride factors (ALFs) are involved in the recognition and elimination of invading pathogens. In this study, the full-length ALF cDNA sequence of the red claw crayfish Cherax quadricarinatus (termed CqALF) was cloned from a suppression subtractive hybridization library constructed using red claw crayfish hematopoietic tissue cell (Hpt cell) cultures following challenge with white spot syndrome virus (WSSV). The full-length cDNA sequence of CqALF was 863 bp, and the open reading frame encoded 123 amino acids with a signal peptide in the N-terminus and a conserved LPS-binding domain. Unlike most ALFs, which are highly expressed in haemocytes, high expression levels of CqALF were detected in epithelium, the stomach and eyestalks, while lower expression was detected in Hpt, nerves, the heart, muscle tissue, gonads, haemocytes, intestines, gills and the hepatopancreas. To further explore the biological activities of CqALF, mature recombinant CqALF protein (rCqALF) was expressed and purified using a eukaryotic expression system, and an antimicrobial activity test was carried out. rCqALF clearly exerted antiviral activity, as evidenced by the severe disruption of the envelope of intact WSSV virions following co-incubation of virions with rCqALF. Additionally, pre-incubation of WSSV with rCqALF resulted in both a significant reduction in WSSV replication in red claw crayfish Hpt cell cultures and an increased survival rate among animals. Furthermore, rCqALF was effective against both Gram-negative bacteria and Gram-positive bacteria, particularly Shigella flexneri and Staphylococcus aureus. A membrane integrity assay suggested that rCqALF was unlikely to disrupt bacterial membrane integrity compared to cecropin P1. Taken together, these data suggest that CqALF may play an important role in immune defence in the crustacean C. quadricarinatus. Copyright © 2016 Elsevier Ltd. All rights reserved.

Candida uthaithanina sp. nov., an anamorphic yeast species in Nakaseomyces clade isolated in Thailand.

PubMed

Limtong, Savitree; Jindamorakot, Sasitorn; Am-In, Somjit; Kaewwichian, Rungluk; Nitiyon, Sukanya; Yongmanitchai, Wichien; Nakase, Takashi

2011-05-01

Three yeast stains were isolated from two unknown fruits (strains DD2-22-1(T) and SK44) and moss (strain ST-449) in Thailand. Analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene sequences of the three strains revealed that they belonged to the same species. In terms of pairwise sequence similarity, Candida cf. glabrata UWO(PS) 98-110.4 and Candida nivariensis were the closest undescribed and recognized taxa, but the levels of nucleotide substitutions were 1.7-1.9% and 2.0-2.2%, respectively. The levels of nucleotide substitutions were sufficient to justify the description of a separate species of Candida. In the phylogenetic tree based on the D1/D2 domain of the LSU rRNA gene the three strains were placed in a separate branch in the Nakaseomyces clade with C. cf. glabrata UWO(PS)98-110.4, C. nivariensis, Candida glabrata, Candida bracarensis, Candida kungkrabaensis and Nakaseomyces delphensis. Phenotypic characteristics of the three strains were similar which included proliferation by multilateral budding, absence of ascospores, arthrospores or ballistospores; negative for Diazonium blue B and urease tests. The major ubiquinone was Q-6. On the basis of the above findings, the three strains were assigned to a single novel species of Candida, for which the name Candida uthaithanina sp. nov is proposed. The type strain is DD2-22-1(T) (= BCC 29899(T) = NBRC 104876(T) = CBS 10932(T)).

Antifungal susceptibilities of Candida, Cryptococcus neoformans and Aspergillus fumigatus from the Asia and Western Pacific region: data from the SENTRY antifungal surveillance program (2010-2012).

PubMed

Pfaller, Michael A; Messer, Shawn A; Jones, Ronald N; Castanheira, Mariana

2015-09-01

The SENTRY Antifungal Surveillance Program monitors global susceptibility rates of newer and established antifungal agents. We report the in vitro activity of seven antifungal agents against 496 contemporary clinical isolates of yeasts and molds. The isolates were obtained from 20 laboratories in the Asia-Western Pacific (APAC) region during 2010 through 2012. Anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole and voriconazole were susceptibility tested using CLSI methods and species-specific interpretive criteria. Sequencing of fks hot spots was performed for echinocandin-resistant strains. Isolates included 13 species of Candida (n=460), 5 species of non-Candida yeasts (21), 5 species of Aspergillus (11) and 4 other molds. Echinocandin resistance was uncommon among eight species of Candida and was only detected in three isolates of Candida glabrata, two from Australia harboring mutations in fks1 (F625S) and fks2 (S663P). Resistance to the azoles was much more common and was observed among all species with the exception of Candida dubliniensis. Fluconazole resistance rates observed with C. glabrata (6.8%) was comparable to that seen with Candida parapsilosis (5.7%) and Candida tropicalis (3.6%). Cross resistance among the triazoles was seen with each of these three species. The mold-active azoles and the echinocandins were all active against isolates of Aspergillus fumigatus. Azole resistance was not detected among the isolates of Cryptococcus neoformans. Antifungal resistance is uncommon among isolates of fungi causing invasive fungal infections in the APAC region. As in other regions of the world, emerging resistance to the echinocandins among invasive isolates of C. glabrata bears close monitoring.

Soaps and germicides as adjunct topical antimycotic agents on candida species implicated in vulvovaginal candidasis.

PubMed

Ogunshe, Adenike A O; Omotoso, Oluwatoyin A; Akindele, Titilayo M

2011-06-01

The study aims at evaluating the potentials of soaps and germicides/disinfectants as adjunct topical anti-vulvovaginal candidasis agents. In vitro inhibitory activities of the test agents, prepared according to the manufacturer's specification for toilet and midwifery purposes were determined using modified agar well-diffusion method. Varied susceptibility patterns were exhibited by Candida albicans (26.5%), C. glabrata (18.4%), C. pseudotropicalis (14.3%) and C. tropicalis (40.8%) implicated in vulvovaginal candidasis, indicating Crusader oil (100%), Meriko (95%), Tetmosol (84.7%) and Aloe (68.4%) as the most inhibitory soaps against the Candida strains. The in vitro inhibitory activities of the germicides and disinfectants ranged between (Dettol; 34.6% and Purit; 84.6%) for C. albicans; (Roberts; 33.3% and Purit; 83.3%) for C. glabrata; (Roberts; 21.4% and Purit; 92.9%) for C. pseudotropicalis; (Dettol; 35.0% and Purit; 87.5%) for C. tropicalis respectively. All the Candida strains were totally inhibited by the germicides and disinfectants at the second lower dilutions, except in Morigad towards C. albicans (69.2%]) C. glabrata (72.2%), C. pseudotropicalis (92.9%) and C. tropicalis (82.5%) but none of the vaginal Lactobacillus strains was inhibited by the soaps, germicides or disinfectant. About 90% of a control group indicated relief after pubic cleansing with soaps, germicides and disinfectants. Results indicatied the safety of soaps, germicides and disinfectants as potential adjunct topical cleansing-agents in cases of vaginal itching and candidasis, a common mucosal infection caused by opportunistic yeasts of the Candida genus.

Atmospheric pressure cold plasma as an antifungal therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun Peng; Wu Haiyan; Sun Yi

2011-01-10

A microhollow cathode based, direct-current, atmospheric pressure, He/O{sub 2} (2%) cold plasma microjet was used to inactive antifungal resistants Candida albicans, Candida krusei, and Candida glabrata in air and in water. Effective inactivation (>90%) was achieved in 10 min in air and 1 min in water. Antifungal susceptibility tests showed drastic reduction of the minimum inhibitory concentration after plasma treatment. The inactivation was attributed to the reactive oxygen species generated in plasma or in water. Hydroxyl and singlet molecular oxygen radicals were detected in plasma-water system by electron spin resonance spectroscopy. This approach proposed a promising clinical dermatology therapy.

Effect of Statin Use on Outcomes of Adults with Candidemia

PubMed Central

Cuervo, Guillermo; Garcia-Vidal, Carolina; Nucci, Marcio; Puchades, Francesc; Fernández-Ruiz, Mario; Mykietiuk, Analía; Manzur, Adriana; Gudiol, Carlota; Pemán, Javier; Viasus, Diego; Ayats, Josefina; Carratalà, Jordi

2013-01-01

Background Statins have immunomodulatory properties and hinder Candida growth. However, it is unknown whether they may improve prognosis in patients with candidemia. We sought to determine the effect of prior statin use on the clinical outcomes of patients suffering candidemia. Methods and Findings Multicenter cohort study of hospitalized adults with candidemia between 2005 and 2011 in six hospitals in Spain, Brazil and Argentina. Of 326 candidemias, 44 (13.5%) occurred in statin users and 282 (86.5%) in statin non-users. The median value of APACHE II at candidemia diagnosis was similar between groups (18 vs. 16; p=.36). Candida albicans was the most commonly isolated species, followed by C. parapsilosis, C. tropicalis, C. glabrata, and C. krusei. There were no differences regarding appropriate empirical antifungal treatment. Statin users had a lower early (5 d) case-fatality rate than non-users (4.5 vs. 17%; p=.031). This effect was not observed with other cardiovascular drugs (aspirin, beta blockers and ACE inhibitors). Independent factor related to early case-fatality rate was APACHE II score (AOR, 1.08; 95% CI, 1.03–1.14; p=.002). An appropriate empirical antifungal therapy (AOR, 0.11; 95% CI, 0.04–0.26; p=<.001) and prior statin use were independently associated with lower early case-fatality (AOR, 0.17; 95% CI, 0.03–0.93; p=.041). Fourteen days (14d) and overall (30d) case-fatality rates were similar between groups (27% vs. 29%; p=0.77 and 40% vs. 44%; p=.66). Conclusions The use of statins might have a beneficial effect on outcomes of patients with candidemia. This hypothesis deserves further evaluation in randomized trials. PMID:24155941

A Drosophila model of myeloproliferative neoplasm reveals a feed-forward loop in the JAK pathway mediated by p38 MAPK signalling

PubMed Central

Pérez, Lidia; Bray, Sarah J.

2017-01-01

ABSTRACT Myeloproliferative neoplasms (MPNs) of the Philadelphia-negative class comprise polycythaemia vera, essential thrombocythaemia and primary myelofibrosis (PMF). They are associated with aberrant numbers of myeloid lineage cells in the blood, and in the case of overt PMF, with development of myelofibrosis in the bone marrow and failure to produce normal blood cells. These diseases are usually caused by gain-of-function mutations in the kinase JAK2. Here, we use Drosophila to investigate the consequences of activation of the JAK2 orthologue in haematopoiesis. We have identified maturing haemocytes in the lymph gland, the major haematopoietic organ in the fly, as the cell population susceptible to induce hypertrophy upon targeted overexpression of JAK. We show that JAK activates a feed-forward loop, including the cytokine-like ligand Upd3 and its receptor, Domeless, which are required to induce lymph gland hypertrophy. Moreover, we present evidence that p38 MAPK signalling plays a key role in this process by inducing expression of the ligand Upd3. Interestingly, we also show that forced activation of the p38 MAPK pathway in maturing haemocytes suffices to generate hypertrophic organs and the appearance of melanotic tumours. Our results illustrate a novel pro-tumourigenic crosstalk between the p38 MAPK pathway and JAK signalling in a Drosophila model of MPNs. Based on the shared molecular mechanisms underlying MPNs in flies and humans, the interplay between Drosophila JAK and p38 signalling pathways unravelled in this work might have translational relevance for human MPNs. PMID:28237966

The Galleria mellonella larvae as an in vivo model for evaluation of Shigella virulence.

PubMed

Barnoy, Shoshana; Gancz, Hanan; Zhu, Yuewei; Honnold, Cary L; Zurawski, Daniel V; Venkatesan, Malabi M

2017-07-04

Shigella spp. causing bacterial diarrhea and dysentery are human enteroinvasive bacterial pathogens that are orally transmitted through contaminated food and water and cause bacillary dysentery. Although natural Shigella infections are restricted to humans and primates, several smaller animal models are used to analyze individual steps in pathogenesis. No animal model fully duplicates the human response and sustaining the models requires expensive animals, costly maintenance of animal facilities, veterinary services and approved animal protocols. This study proposes the development of the caterpillar larvae of Galleria mellonella as a simple, inexpensive, informative, and rapid in-vivo model for evaluating virulence and the interaction of Shigella with cells of the insect innate immunity. Virulent Shigella injected through the forelegs causes larvae death. The mortality rates were dependent on the Shigella strain, the infectious dose, and the presence of the virulence plasmid. Wild-type S. flexneri 2a, persisted and replicated within the larvae, resulting in haemocyte cell death, whereas plasmid-cured mutants were rapidly cleared. Histology of the infected larvae in conjunction with fluorescence, immunofluorescence, and transmission electron microscopy indicate that S. flexneri reside within a vacuole of the insect haemocytes that ultrastructurally resembles vacuoles described in studies with mouse and human macrophage cell lines. Some of these bacteria-laden vacuoles had double-membranes characteristic of autophagosomes. These results suggest that G. mellonella larvae can be used as an easy-to-use animal model to understand Shigella pathogenesis that requires none of the time and labor-consuming procedures typical of other systems.

The Galleria mellonella larvae as an in vivo model for evaluation of Shigella virulence

PubMed Central

Barnoy, Shoshana; Gancz, Hanan; Zhu, Yuewei; Honnold, Cary L.; Venkatesan, Malabi M.

2017-01-01

ABSTRACT Shigella spp. causing bacterial diarrhea and dysentery are human enteroinvasive bacterial pathogens that are orally transmitted through contaminated food and water and cause bacillary dysentery. Although natural Shigella infections are restricted to humans and primates, several smaller animal models are used to analyze individual steps in pathogenesis. No animal model fully duplicates the human response and sustaining the models requires expensive animals, costly maintenance of animal facilities, veterinary services and approved animal protocols. This study proposes the development of the caterpillar larvae of Galleria mellonella as a simple, inexpensive, informative, and rapid in-vivo model for evaluating virulence and the interaction of Shigella with cells of the insect innate immunity. Virulent Shigella injected through the forelegs causes larvae death. The mortality rates were dependent on the Shigella strain, the infectious dose, and the presence of the virulence plasmid. Wild-type S. flexneri 2a, persisted and replicated within the larvae, resulting in haemocyte cell death, whereas plasmid-cured mutants were rapidly cleared. Histology of the infected larvae in conjunction with fluorescence, immunofluorescence, and transmission electron microscopy indicate that S. flexneri reside within a vacuole of the insect haemocytes that ultrastructurally resembles vacuoles described in studies with mouse and human macrophage cell lines. Some of these bacteria-laden vacuoles had double-membranes characteristic of autophagosomes. These results suggest that G. mellonella larvae can be used as an easy-to-use animal model to understand Shigella pathogenesis that requires none of the time and labor-consuming procedures typical of other systems. PMID:28277944

The epidemiology of Candida species associated with vulvovaginal candidiasis in an Iranian patient population.

PubMed

Mahmoudi Rad, M; Zafarghandi, S; Abbasabadi, B; Tavallaee, M

2011-04-01

and those who had orogenital sex were more likely to suffer recurrent vulvovaginal candidiasis. Candida albicans was the most common cause of recurrent and non-recurrent vulvovaginitis. The second most common species was Candida glabrata. This study suggests CHROMagar method as a convenient and cost effective yet reliable method to isolate the species of Candida especially in cases where more than one species is present. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Is empiric therapy with fluconazole appropriate for esophageal candidiasis?

PubMed

Sajith, Kattiparambil Gangadharan; Dutta, Amit Kumar; Sahni, Rani Diana; Esakimuthu, Saritha; Chacko, Ashok

2014-03-01

We studied the prevalence of fluconazole resistance in esophageal candidiasis. Patients with suspected esophageal candidiasis during gastroscopy underwent culture of white plaques. Minimum inhibitory concentration (MIC) >64 μg/mL of fluconazole for Candida was indicative of resistance. Sensitivity of itraconazole was tested in a subset of resistant strains. Sixty-five patients were included. Mean (SD) age was 50.03 (13.5) years and 67.7 % were males. Predisposing factors for candidiasis were found in 42 (64.6 %) patients. C. albicans was identified in 64 (97.4 %) patients and C. glabrata in one patient. Fluconazole resistance was seen in 38 (59.4 %) patients with C. albicans and also in the one patient with C. glabrata. All the fluconazole resistant isolates of C. albicans had MIC >128 μg/mL suggesting very high resistance. Twelve patients with fluconazole resistance had itraconazole resistance as well. The study shows a high rate of fluconazole resistance in patients with esophageal candidiasis.

Saccharomyces cerevisiae show low levels of traversal across human endothelial barrier in vitro.

PubMed

Pérez-Torrado, Roberto; Querol, Amparo

2017-01-01

Background :   Saccharomyces cerevisiae is generally considered safe, and is involved in the production of many types of foods and dietary supplements. However, some isolates, which are genetically related to strains used in brewing and baking, have shown virulent traits, being able to produce infections in humans, mainly in immunodeficient patients. This can lead to systemic infections in humans. Methods : In this work, we studied S. cerevisiae isolates in an in vitro human endothelial barrier model, comparing their behaviour with that of several strains of the related pathogens Candida glabrata and Candida albicans . Results : The results showed that this food related yeast is able to cross the endothelial barrier in vitro . However, in contrast to C. glabrata and C. albicans , S. cerevisiae showed very low levels of traversal. Conclusions : We conclude that using an in vitro human endothelial barrier model with S. cerevisiae can be useful to evaluate the safety of S. cerevisiae strains isolated from foods.

Clinical Saccharomyces cerevisiae isolates cannot cross the epithelial barrier in vitro.

PubMed

Pérez-Torrado, Roberto; Llopis, Silvia; Jespersen, Lene; Fernández-Espinar, Teresa; Querol, Amparo

2012-06-15

Saccharomyces cerevisiae is generally considered to be a safe organism and is essential to produce many different kinds of foods as well as being widely used as a dietary supplement. However, several isolates, which are genetically related to brewing and baking yeasts, have shown virulent traits, being able to produce human infections in immunodeficient patients. Previously it has been shown that the administration of S. cerevisiae clinical isolates can lead to systemic infections, reaching several organs in murine systems. In this work, we studied S. cerevisiae clinical isolates in an in vitro intestinal epithelial barrier model, comparing their behaviour with that of several strains of the related pathogens Candida glabrata and Candida albicans. The results showed that, in contrast to C. glabrata and C. albicans, S. cerevisiae was not able to cross the intestinal barrier. We concluded that S. cerevisiae can only perform opportunistic or passive crossings when epithelial barrier integrity is previously compromised. Copyright © 2012 Elsevier B.V. All rights reserved.

[Fungal diseases of vulva and vagina caused by Candida species].

PubMed

Stock, Ingo

2010-09-01

Fungal diseases of vulva and vagina attributed to Candida species (vulvovaginal candidosis) are the most frequent mycoses of women. They show acute or chronic courses and different disease patterns which can strongly affect the quality of life of the women who are concerned. In general, the most common cause of acute vulvovaginal candidosis is Candida albicans, followed by C. glabrata. In chronic recurrent vulvovaginal candidosis, C. albicans and C. glabrata are often equally distributed. In several cases, treatment requires an antimycotic therapy which refers to the severity and main form of disease as well as to the aetiological agent. Most vulvovaginal candidoses are accessible to the treatment with local and systemic antimycotic agents. Generally, in Germany azoles such as clotrimazole, fluconazole and itraconazole, the polyens nystatin and Amphotericin B and the hydroxypyridone derivative ciclopirox are available for antimycotic therapy of vulvovaginal candidoses. Significance of non-conventional and adjuvant therapeutic approaches is considered to be generally low.

Assessment of schistosomiasis in the Dominican Republic.

PubMed Central

Schneider, C R; Hiatt, R A; Malek, E A; Ruiz-Tiben, E

1985-01-01

Active transmission of intestinal schistosomiasis is currently limited to the southeastern part of the Dominican Republic. A population-based stool survey in 1980 detected 4 asymptomatic individuals among 114 selected at random in 2 towns and a rural community in El Seibo Province. The distribution of the transmitting snail, Biomphalaria glabrata, considerably exceeds that of Schistosoma mansoni, extending to the National District and capital city of Santo Domingo and well into certain central valley provinces. There is evidence that transmission sites have shifted during the past three decades because of urban development, molluscicidal activities and, perhaps, introduction of competing mollusks. In spite of intermittent control activities, the combination of domestic and recreational use of streams with consequent fecal contamination, and the extended distribution of B. glabrata indicates that the potential for new transmission foci is as great today as it was 10 years ago. This potential transmission of S. mansoni is a continuing threat to public health in the Dominican Republic. PMID:3931167

The transcriptional response of the Pacific oyster Crassostrea gigas against acute heat stress.

PubMed

Yang, Chuanyan; Gao, Qiang; Liu, Chang; Wang, Lingling; Zhou, Zhi; Gong, Changhao; Zhang, Anguo; Zhang, Huan; Qiu, Limei; Song, Linsheng

2017-09-01

The Pacific oyster, Crassostrea gigas, has evolved sophisticated mechanisms to adapt the changing ambient conditions, and protect themselves from stress-induced injuries. In the present study, the expression profiles of mRNA transcripts in the haemocytes of oysters under heat stress were examined to reveal the possible mechanism of heat stress response. There were 23,315, 23,904, 23,123 and 23,672 transcripts identified in the haemocytes of oysters cultured at 25 °C for 0, 6, 12, and 24 h (designed as B, H6, H12, H24), respectively. And 22,330 differentially expressed transcripts (DTs) were yielded in the pairwise comparisons between the above four samples, which corresponded to 8074 genes. There were 9, 12 and 22 Gene Ontology (GO) terms identified in the DT pairwise comparison groups of H6_B, H12_H6 and H24_H12, respectively, and the richest GO terms in biological process category were cellular catabolic process, translational initiation and apoptotic process, respectively. There were 108, 102 and 102 KEGG pathways successfully retrieved from DTs comparison groups DTH6_B, DTH12_H6 and DTH24_H12, respectively, among which 93 pathways were shared by all three comparison groups, and most of them were related to metabolism of protein, carbohydrate and fat. The expression patterns of 12 representative heat stress response-relevant genes detected by quantitative real-time PCR (qRT-PCR) were similar to those obtained from transcriptome analysis. By flow cytometric analysis, the apoptosis rate of haemocytes increased significantly after oysters were treated at 25 °C for 24 h and recovered at 4 °C for 12 h (p < 0.05) and 36 h (p < 0.01), and it also increased significantly when the heat treatment lasted to 60 h (p < 0.01). The present results indicated that, when oysters encountered short term heat stress, the expression of genes related to energy metabolism, as well as unfolded protein response (UPR) and anti-apoptotic system, were firstly regulated to

Survey of the Antibiofilm and Antimicrobial Effects of Zingiber officinale (in Vitro Study)

PubMed Central

Aghazadeh, Marzieh; Zahedi Bialvaei, Abed; Aghazadeh, Mohammad; Kabiri, Fahimeh; Saliani, Negar; Yousefi, Mehdi; Eslami, Hosein; Samadi Kafil, Hossein

2016-01-01

Background: Candidiasis is one of the most prevalent and important opportunistic fungal infections of the oral cavity caused by Candida yeast species like Candida albicans, C. glabrata, and C. krusei. In addition, several bacteria can cause oral infections. The inhibition of microbial biofilm is the best way to prevent oral infections. Objectives: The aim of the present study is to evaluate the antifungal, antimicrobial, and anti-biofilm properties of ginger (Zingiber officinale) extract against Candida species and some bacterial pathogens and the extract’s effects on biofilm formation. Materials and Methods: Ginger ethanolic extract as a potential mouthwash was used to evaluate its effect against fungi and bacteria using the microdilution method, and biofilm was evaluated using the crystal violet staining method and dead/alive staining. MTT assay was used to evaluate the possible cytotoxicity effects of the extract. Results: The minimum inhibitory concentrations (MICs) of ginger extract for evaluated strains were 40, 40, 20, 20, 20, 20, 10, and 5 mg/mL for Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus cereus, Acinetobacter baumannii, C. albicans, and C. krusei, respectively. Ginger extract successfully inhibited biofilm formation by A. baumannii, B. cereus, C. krusei, and C. albicans. MTT assay revealed no significant reduction in cell viability after 24 hours. The minimum inhibitory biofilm concentrations (MIBCs) of ginger extract for fungi strains (C. krusei and C. albicans) were greater than those of fluconazole and nystatin (P = 0.000). Conclusions: The findings of the present study indicate that ginger extract has good antifungal and antibiofilm formation by fungi against C. albicans and C. Krusei. Concentrations between 0.625 mg/mL and 5 mg/mL had the highest antibiofilm and antifungal effects. Perhaps, the use of herbal extracts such as ginger represents a new era for antimicrobial therapy after

Survey of the Antibiofilm and Antimicrobial Effects of Zingiber officinale (in Vitro Study).

PubMed

Aghazadeh, Marzieh; Zahedi Bialvaei, Abed; Aghazadeh, Mohammad; Kabiri, Fahimeh; Saliani, Negar; Yousefi, Mehdi; Eslami, Hosein; Samadi Kafil, Hossein

2016-02-01

Candidiasis is one of the most prevalent and important opportunistic fungal infections of the oral cavity caused by Candida yeast species like Candida albicans, C. glabrata, and C. krusei. In addition, several bacteria can cause oral infections. The inhibition of microbial biofilm is the best way to prevent oral infections. The aim of the present study is to evaluate the antifungal, antimicrobial, and anti-biofilm properties of ginger (Zingiber officinale) extract against Candida species and some bacterial pathogens and the extract's effects on biofilm formation. Ginger ethanolic extract as a potential mouthwash was used to evaluate its effect against fungi and bacteria using the microdilution method, and biofilm was evaluated using the crystal violet staining method and dead/alive staining. MTT assay was used to evaluate the possible cytotoxicity effects of the extract. The minimum inhibitory concentrations (MICs) of ginger extract for evaluated strains were 40, 40, 20, 20, 20, 20, 10, and 5 mg/mL for Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus cereus, Acinetobacter baumannii, C. albicans, and C. krusei, respectively. Ginger extract successfully inhibited biofilm formation by A. baumannii, B. cereus, C. krusei, and C. albicans. MTT assay revealed no significant reduction in cell viability after 24 hours. The minimum inhibitory biofilm concentrations (MIBCs) of ginger extract for fungi strains (C. krusei and C. albicans) were greater than those of fluconazole and nystatin (P = 0.000). The findings of the present study indicate that ginger extract has good antifungal and antibiofilm formation by fungi against C. albicans and C. Krusei. Concentrations between 0.625 mg/mL and 5 mg/mL had the highest antibiofilm and antifungal effects. Perhaps, the use of herbal extracts such as ginger represents a new era for antimicrobial therapy after developing antibiotic resistance in microbes.

CHROMagar Candida as the Sole Primary Medium for Isolation of Yeasts and as a Source Medium for the Rapid-Assimilation-of-Trehalose Test

PubMed Central

Murray, Melissa P.; Zinchuk, Riva; Larone, Davise H.

2005-01-01

The chromogenic medium BBL CHROMagar Candida (CAC) was evaluated as a sole primary medium for the isolation of yeasts from clinical specimens in which yeasts are the primary concern. Additionally, the reliability of the rapid-assimilation-of-trehalose (RAT) test in yielding correct results with isolates taken from CAC was assessed. A total of 270 throat, urine, and genital (TUG) specimens were streaked onto CAC, Sabouraud dextrose agar (SDA), inhibitory mold agar (IMA), and Mycosel (MYC). A total of 69 blood culture broths that were smear positive for yeast were streaked onto CAC and SDA. A 1-h RAT test (NCCLS M35-A) was performed simultaneously on isolates from CAC and SDA. A total of 112 TUG specimens yielded yeast colonies (CAC, 111 colonies; IMA, 105; SDA, 103; MYC, 91). The 69 blood culture yeasts grew on both CAC and SDA. Mixed cultures of yeasts were detected on 11 CAC plates but were unrecognized on other media. Colonies suspected of being C. glabrata on 32 CAC plates were all RAT test positive and confirmed to be C. glabrata; of 59 colonies with various characteristics of color and morphology on CAC, none were RAT positive, and all were conventionally identified as yeasts other than C. glabrata (sensitivity and specificity, 100%). The same isolates from SDA tested for RAT produced six false negatives and no false positives (sensitivity, 81%; specificity, 100%). The results show that CAC can be used as the sole primary medium for recovery of yeasts from clinical specimens. Additionally, isolates grown on CAC yield excellent results with the RAT test utilized in this study. PMID:15750085

Five-year National Surveillance of Invasive Candidiasis: Species Distribution and Azole Susceptibility from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) Study.

PubMed

Xiao, Meng; Sun, Zi-Yong; Kang, Mei; Guo, Da-Wen; Liao, Kang; Chen, Sharon C-A; Kong, Fanrong; Fan, Xin; Cheng, Jing-Wei; Hou, Xin; Zhou, Meng-Lan; Li, Ying; Yu, Shu-Ying; Huang, Jing-Jing; Wang, He; Xu, Ying-Chun

2018-05-09

Data on the epidemiology of invasive candidiasis (IC) and antifungal susceptibility of Candida isolates in China are still limited. Here we report surveillance for IC from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) Study. Sixty-five tertiary hospitals collected 8,829 Candida isolates from August 1, 2009 to July 31, 2014. Matrix-assisted laser desorption/ionization -time of flight mass spectrometry supplemented by rDNA sequencing was used to define species, and fluconazole and voriconazole susceptibilities determined by the Clinical and Laboratory Standards Institute disk diffusion method. A total of 32 Candida species were identified. C. albicans was the most common species (44.9%) followed by C. parapsilosis complex (20.0%), C. tropicalis (17.2%) and C. glabrata complex (10.8%), with other species comprising <3%. However, in candidemia, the proportion of cases caused by C. albicans was only 32.3%. C. albicans and C. parapsilosis complex isolates were susceptible to fluconazole and voriconazole (<6% resistance), while fluconazole- and azole cross-resistant rates were high in C. tropicalis (13.3% and 12.9%), C. glabrata complex (18.7% and 14%) and uncommon Candida species (44.1% and 10.3%) isolates. Moreover, from year 1 to 5 of the study, there was a significant increase in resistant rates amongst C. glabrata complex isolates to fluconazole (12.2% to 24.0%), and amongst C. tropicalis isolates to both fluconazole (5.7% to 21.0%) and voriconazole (5.7% to 21.4%) (all P<0.01). Geographic variations in causative species and susceptibilities were noted. Our findings indicated that antifungal resistance have become noteworthy in China, and enhanced surveillance is warranted. Copyright © 2018 American Society for Microbiology.

[Determination of in vitro susceptibility of Candida species to amphotericin B by E-test and previously proposed MIC breakpoints on two different media].

PubMed

Alp, Sehnaz; Sancak, Banu; Arikan, Sevtap

2008-04-01

Although much work has concentrated on defining a reliable and reproducible method for determining in vitro susceptibility of Candida species to amphotericin B, there still has been limitations of the proposed techniques. In this study, amphotericin B minimal inhibitory concentrations (MIC) and susceptibility categories of 212 Candida strains (57 C. glabrata, 53 C. lusitaniae, 51 C. krusei and 51 C. tropicalis) were determined by E-test on RPMI agar (RPG) and antibiotic medium 3 agar (AM3) both supplemented with 2% glucose. The results were interpreted according to the proposed MIC breakpoints (> or = 0.38 microg/ml on RPG, >1 microg/ml on AM3) and discrepancies between susceptibility categories were investigated. While all Candida strains included in the study were determined to be susceptible on AM3 by amphotericin B E-test at 48h, 36.3% of the isolates were classified as resistant on RPG at 48 hours. On RPG, C. krusei strains showed the highest resistance rate (94.1% at 48 h), followed by C. tropicalis (35.3% at 48 h) and C. glabrata (17.5% at 48h). At 48h of incubation, 98.1% of C. lusitaniae isolates were found to be susceptible on RPG. The categorical agreement rates between the results obtained on two media and for C. lusitaniae and C. glabrata were 98.1% and 82.5% at 48 hours. For C. tropicalis and C. krusei, the rates of agreement were 64.7% and 5.9% at 48 hours. Conclusively, according to the previously proposed MIC breakpoints for amphotericin B E-test on RPG and AM3, discrepancies between susceptibility categories of Candida species were of remarkable significance.

CHROMagar Candida as the sole primary medium for isolation of yeasts and as a source medium for the rapid-assimilation-of-trehalose test.

PubMed

Murray, Melissa P; Zinchuk, Riva; Larone, Davise H

2005-03-01

The chromogenic medium BBL CHROMagar Candida (CAC) was evaluated as a sole primary medium for the isolation of yeasts from clinical specimens in which yeasts are the primary concern. Additionally, the reliability of the rapid-assimilation-of-trehalose (RAT) test in yielding correct results with isolates taken from CAC was assessed. A total of 270 throat, urine, and genital (TUG) specimens were streaked onto CAC, Sabouraud dextrose agar (SDA), inhibitory mold agar (IMA), and Mycosel (MYC). A total of 69 blood culture broths that were smear positive for yeast were streaked onto CAC and SDA. A 1-h RAT test (NCCLS M35-A) was performed simultaneously on isolates from CAC and SDA. A total of 112 TUG specimens yielded yeast colonies (CAC, 111 colonies; IMA, 105; SDA, 103; MYC, 91). The 69 blood culture yeasts grew on both CAC and SDA. Mixed cultures of yeasts were detected on 11 CAC plates but were unrecognized on other media. Colonies suspected of being C. glabrata on 32 CAC plates were all RAT test positive and confirmed to be C. glabrata; of 59 colonies with various characteristics of color and morphology on CAC, none were RAT positive, and all were conventionally identified as yeasts other than C. glabrata (sensitivity and specificity, 100%). The same isolates from SDA tested for RAT produced six false negatives and no false positives (sensitivity, 81%; specificity, 100%). The results show that CAC can be used as the sole primary medium for recovery of yeasts from clinical specimens. Additionally, isolates grown on CAC yield excellent results with the RAT test utilized in this study.

Site-specific mesenchymal control of inflammatory pain to yeast challenge in vulvodynia afflicted and pain-free women

PubMed Central

Foster, David C.; Falsetta, Megan L.; Woeller, Collynn F.; Pollock, Stephen J.; Song, Kunchang; Bonham, Adrienne; Haidaris, Constantine G.; Stodgell, Chris J.; Messing, Susan P.; Iadarola, Michael; Phipps, Richard P.

2015-01-01

Fibroblast strains were derived from two regions of the lower genital tract of localized provoked vulvodynia (LPV) cases and pain-free controls. Sixteen strains were derived from four cases and four controls, age and race matched, following pre-sampling mechanical pain threshold assessments. Strains were challenged with six separate stimuli: live yeast species (C. albicans, C. glabrata, C. tropicalis, and S. cerevisiae), yeast extract (zymosan), or inactive vehicle. Production of prostaglandin E2 (PGE2) and interleukin-6 (IL-6) were pro-inflammatory response measures. Highest IL-6 and PGE2 occurred with vestibular strains following C. albicans, C. glabrata, and zymosan challenges, resulting in the ability to significantly predict IL-6 and PGE2 production by genital tract location. Following C. albicans and C. glabrata challenge of all sixteen fibroblast strains, adjusting for dual sampling of subjects, PGE2 and IL-6 production significantly predicted the pre-sampling pain threshold from the genital tract site of sampling. At the same location of pain assessment and fibroblast sampling, in situ immunohistochemical (IHC)(+) fibroblasts for IL-6 and Cox-2 were quantified microscopically. The correlation between IL-6 production and IL-6 IHC(+) was statistically significant yet biological significance is unknown because of the small number of IHC(+) IL-6 fibroblasts identified. A low fibroblast IL-6 IHC(+) count may result from most IL-6 produced by fibroblasts existing in a secreted, extracellular state. Enhanced, site-specific, innate immune responsiveness to yeast pathogens by fibroblasts may be an early step in LPV pathogenesis. Fibroblast strain testing may offer an attractive/objective marker of LPV pathology in women with vulvodynia of inflammatory origin. PMID:25679469

Invasive candidiasis in intensive care units in China: in vitro antifungal susceptibility in the China-SCAN study.

PubMed

Liu, Wei; Tan, Jingwen; Sun, Jimei; Xu, Zhijiang; Li, Min; Yang, Qing; Shao, Haifeng; Zhang, Liyan; Liu, Weixia; Wan, Zhe; Cui, Wei; Zang, Bin; Jiang, Dongpo; Fang, Qiang; Qin, Bingyu; Qin, Tiehe; Li, Weiqin; Guo, Fengmei; Liu, Dawei; Guan, Xiandong; Yu, Kaijiang; Qiu, Haibo; Li, Ruoyu

2014-01-01

The objectives of this study were to determine species distribution and in vitro antifungal susceptibility of Candida isolates identified in the multicentre China-SCAN study of invasive Candida infection (ICI) in intensive care units (ICUs) across China. Candida isolates from patients in the China-SCAN study with documented ICI were evaluated by a central laboratory. Species were identified using chromogenic culture media or the API 20C AUX kit. Susceptibility to fluconazole, voriconazole, itraconazole, caspofungin and amphotericin B was determined using the CLSI broth microdilution method (M27-A3) and updated clinical breakpoints or epidemiological cut-off values. A total of 389 isolates from 244 patients were analysed. Species identified most frequently were Candida albicans (40.1%), Candida parapsilosis (21.3%), Candida tropicalis (17.2%) and Candida glabrata (12.9%). Rarer species such as Lodderomyces elongisporus and Candida ernobii were also identified. Fluconazole susceptibility was evident in 85.9% (134/156) of C. albicans, 62.7% (42/67) of C. tropicalis and 48.2% (40/83) of C. parapsilosis isolates. Susceptibility to voriconazole was ≥ 90% among all species. All isolates were susceptible to amphotericin B and caspofungin except C. glabrata [86.0% (43/50) susceptible to caspofungin]. Cross-resistance between fluconazole and voriconazole was observed for C. parapsilosis and C. glabrata. Although C. albicans was the predominant single species, non-albicans species constituted >50% of isolates. Fluconazole susceptibility was lower in most non-albicans species, indicating that fluconazole resistance should be closely monitored. Susceptibility to voriconazole, amphotericin B and caspofungin is encouraging. Differences between these data and those from other regions emphasize the importance of assessing regional variations.

Etiologic agents of cervicovaginitis in Turkish women.

PubMed

Ozturk, Cihadiye E; Ozdemir, Ismail; Yavuz, Tevfik; Kaya, Demet; Behcet, Mustafa

2006-10-01

To investigate the distribution of microbiologic agents causing cervicovaginitis. We conducted the study between October 2002 and December 2004 in Abant Izzet Baysal University, Duzce School of Medicine Hospital, Turkey. The samples were obtained from the posterior vaginal fornix and cervix by swabs in 828 patients. Direct microscopic examination, culture and enzyme immune assay (EIA) methods were performed in all patients for diagnosis of microbiologic agents. Gardnerella vaginalis (G. vaginalis) were diagnosed in 254 (30.7%) patients, Candida albicans (C. albicans) in 152 (18.4%), Candida glabrata (C. glabrata) in 36 (4.3%), Candida species in 52 (6.3%), Staphylococcus aureus (S. aureus) in 62 (7.5%), Streptococcus group B in 28 (3.4%), Escherichia coli (E. coli) in 42 (5.1%), Klebsiella species in 24 (2.9%), and Streptococcus group D in 8 (1%) patients in culture. Less frequent enterobacteria in 30 (3.6%) were: Pseudomonas species, Proteus species Enterobacter species, Hafnia alvei and Nonfermenter species. Neisseria gonorrheae (N. gonorrheae) was detected in one patient (0.1%) in culture. The Chlamydia trachomatis (C. trachomatis) antigen was detected by EIA methods in 130 (15.7%) patients and Trichomonas vaginalis (T. vaginalis) was observed in 8 (1%) patients by direct microscopic examination. Performing the etiologic diagnosis of cervicovaginitis is necessary in order to take appropriate therapeutic and preventive measures. Therefore, we recommend G. vaginalis, C. albicans and C. trachomatis should be investigated in patients having a diagnosis of cervicovaginitis in our population, since these were detected in a considerable number of cases. Additionally, C. glabrata and T. vaginalis should be kept in mind as possible pathogens.

Prevalence of Candida co-infection in patients with pulmonary tuberculosis.

PubMed

Kali, Arunava; Charles, Mv Pravin; Noyal, Mariya Joseph; Sivaraman, Umadevi; Kumar, Shailesh; Easow, Joshy M

2013-01-01

Candida species are emerging as a potentially pathogenic fungus in patients with broncho-pulmonary diseases. The synergistic growth promoting association of Candida and Mycobacterium tuberculosis has raised increased concern for studying the various Candida spp . and its significance in pulmonary tuberculosis patients during current years. This study was undertaken with the objective of discovering the prevalence of co-infection caused by different Candida species in patients with pulmonary tuberculosis. A total of 75 patients with pulmonary tuberculosis diagnosed by sputum Ziehl-Neelsen staining were included in the study. Candida co-infection was confirmed using the Kahanpaa et al. criteria. Candida species were identified using gram stain morphology, germ tube formation, morphology on cornmeal agar with Tween-80, sugar fermentation tests and HiCrome Candida Agar. Candida co-infection was observed in 30 (40%) of patients with pulmonary tuberculosis. Candida albicans was the most common isolate observed in 50% of the patients with co-infection, followed by C. tropicalis (20%) and C. glabrata (20%). Candida co-infection was found in 62.5% of female patients, while it was observed in only 29.4% of the male patients (P value 0.0133). Mean ± SD age of the patients with C. glabrata infection was 65.83 ± 3.19, while the mean ± SD age of the patients with other Candida infections was 43.25 ± 20.44 (P value 0.0138). Many patients with pulmonary tuberculosis have co-infection with Candida spp. The prevalence of non-albicans Candida species is increasing and may be associated with inadequate response to anti-tubercular drugs. C. glabrata infection has a strong association with old age.

Evaluation of esterase and hemolysin activities of different Candida species isolated from vulvovaginitis cases in Lorestan Province, Iran.

PubMed

Noori, Maryam; Dakhili, Mohammad; Sepahvand, Asghar; Davari, Nader

2017-12-01

Annually affecting millions of women, vulvovaginal candidiasis (VVC) is commonly described by signs and symptoms of vulvovaginal inflammation in the presence of  Candida  species. Today, the detection of the virulence factors plays a major role in the understanding of pathogenesis of candidiasis and helps produce new anticandidial drugs to improve its treatment efficiency. Herein, we aimed to evaluate the esterase and hemolysin activities of the vaginal isolates of Candida and their relationship with the presence of VVC. One-hundred vaginal clinical specimens were randomly collected during September-December 2016. The target population consisted of married women suspected of VVC who presented to health centers in Lorestan Province, Iran. In this study, the esterase activity and hemolysin production of Candida clinical isolates were evaluated using the Tween 80 opacity test and the plate assay, respectively. The most frequent Candida species was C. albicans (66; 66%), followed by C. glabrata (11; 11%) and C. tropicalis (11; 11%). The highest esterase activity was found in C. krusei (75%), followed by C. albicans (68.2%) and C. glabrata (54.5%). The greater part of the positive esterase isolates had Pz 4+ scores. Among the Candida species, C. albicans (22.7 % ), C. glabrata (63.6%), and C. krusei (50%) were found to have the highest rates of alpha, beta, and gamma hemolysin production, respectively. The level of hemolytic activity in 51% of the Candida species was Pz 4+ scores. According to our results, the higher expression rates of both enzymes in C. albicans species relative to those of non-albicans Candidate species can partly reflect the role of the virulence factors involved in C. albicans pathogenicity.

Commonly used oncology drugs decrease antifungal effectiveness against Candida and Aspergillus species.

PubMed

Butts, Arielle; Reitler, Parker; Ge, Wenbo; Fortwendel, Jarrod R; Palmer, Glen E

2018-04-30

The incidence of invasive fungal infections has risen significantly in recent decades as medical interventions have become increasingly aggressive. These infections are extremely difficult to treat due to the extremely limited repertoire of systemic antifungals, the development of drug resistance, and the extent of to which the patient's immune function is compromised. Even when the appropriate antifungal therapies are administered in a timely fashion, treatment failure is common, frequently even in the absence of in vitro microbial resistance. In this study, we screened a small collection of FDA approved oncolytic agents for compounds that impact the efficacy of the two most widely used classes of system antifungals against Candida albicans, Candida glabrata , and Aspergillus fumigatus We have identified several drugs that enhance fungal growth in the presence of the azole antifungals and examine the potential that these drugs directly affect fungal fitness, specifically antifungal susceptibility, and may be contributing to clinical treatment failure. Copyright © 2018 American Society for Microbiology.

Antifungal Activity of Propolis Against Yeasts Isolated From Blood Culture: In Vitro Evaluation.

PubMed

Mutlu Sariguzel, Fatma; Berk, Elife; Koc, Ayes Nedret; Sav, Hafize; Demir, Gonca

2016-09-01

Due to the failure of available antifungal agents in the treatment of candidemia and the toxic activities of these drugs, a lot of researches are being conducted to develop new nontoxic and effective antifungal agents for optimal control of fungal pathogens. The aim of this study is to evaluate the in vitro antifungal activity of propolis against yeasts isolated from the blood cultures of intensive care unit patients. Seventy-six strains were included in this study. The in vitro antifungal activity of propolis, fluconazole (FLU), and itraconazole (ITR) was investigated by the microdilution broth methods (CLSI guidelines M27-A3 for yeast). The propolis sample was collected from Kayseri, Turkey. Of the 76 isolates, 33 were identified as Candida albicans while 37 were C. parapsilosis, three were C. tropicalis, and three were identified as C. glabrata. The geometric mean range for MIC (μg/ml) with regard to all isolates was 0.077 to 3 μg/ml for FLU and ITR, and 0.375 to 0.70 μg/ml for propolis. It was shown that propolis had significant antifungal activity against all Candida strains and the MIC range of propolis was determined as 0185 to 3 μg/ml. This study demonstrated that propolis had significant antifungal activity against yeasts isolated from blood culture compared with FLU and ITR. The propolis MIC in azole-resistant strains such as C. glabrata was found lower than the FLU MIC. © 2015 Wiley Periodicals, Inc.

Antifungal susceptibilities of Candida species isolated from urine culture.

PubMed

Toka Özer, Türkan; Durmaz, Süleyman; Yula, Erkan

2016-09-01

Candida spp. are the most common opportunistic mycosis worldwide. Although Candida albicans is the most common cause of urinary tract infections, the frequency of non-albicans Candida species is increasing with common use of antifungal in the prophylaxis and treatment. This may lead to difficulties in treatment. Antifungal tests should be applied with identification of species for effective treatment. In this study, identification of Candida species isolated from urine culture and investigation of susceptibility of these strains to amphotericin B, flucytosine, fluconazole, voriconazole was aimed. In this study, 58 Candida strains isolated from urine cultures at Osmaniye State Hospital between January 2012 and April 2013 were included. Urine culture and antifungal susceptibility tests were applied. Incidence rate of Candida spp. was determined as C. albicans (56.9%), Candida glabrata (20.6%), Candida tropicalis (10.3%), Candida parapsilosis (7%), Candida krusei (3.4%), Candida kefyr (1.8%). Most of the isolates were susceptible to amphotericin B, flucytosine, fluconazole, voriconazole. Twenty three (39.7%) Candida strains were isolated from internal medical branches and Intensive Care Unit and 12 (20.6%) from the Surgical Medical Branches. C. albicans and C. glabrata species were isolated most frequently as a candiduria factor in this hospital between January 2012 and April 2013. The analysis of antifungal susceptibility profile shows no significant resistance to antifungals. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Yeast Colonization and Drug Susceptibility Pattern in the Pediatric Patients With Neutropenia

PubMed Central

Haddadi, Pedram; Zareifar, Soheila; Badiee, Parisa; Alborzi, Abdolvahab; Mokhtari, Maral; Zomorodian, Kamiar; Pakshir, Keyvan; Jafarian, Hadis

2014-01-01

Background: Pediatric patients with neutropenia are vulnerable to invasive Candida infections. Candida is the primary cause of fungal infections, particularly in immunosuppressed patients. Candida albicans has been the most common etiologic agent of these infections, affecting 48% of patients Objectives: The aim of this study was to identify Candida spp. isolated from children with neutropenia and determine the antifungal susceptibility pattern of the isolated yeasts. Patients and Methods: In this study 188 children with neutropenia were recruited, fungal surveillance cultures were carried out on nose, oropharynx, stool, and urine samples. Identification of Candida strains was performed using germ tube and chlamydospore production tests on an API 20 C AUX system. Susceptibility testing on seven antifungal agents was performed using the agar-based E-test method. Results: A total of 229 yeasts were isolated. Among those, C. albicans was the most common species followed by C. krusei, C. parapsilosis, C. glabrata, C. tropicalis, C. famata, C. dubliniensis, C. kefyr, and other Candida species. C. glabrata was the most resistant isolated yeasts, which was 70% resistant to fluconazole and 50% to itraconazole, 7.5% to amphotericin B and 14% to ketoconazole. All the tested species were mostly sensitive to caspofungin. Conclusions: Knowledge about the susceptibility patterns of colonized Candida spp. can be helpful for clinicians to manage pediatric patients with neutropenia. In this study, caspofungin was the most effective antifungal agent against the colonized Candida spp. followed by conventional amphotericin B. PMID:25485060

Tissue-specific assimilation, depuration and toxicity of nickel in Mytilus edulis.

PubMed

Millward, Geoffrey E; Kadam, Sandeep; Jha, Awadhesh N

2012-03-01

The tissue-specific accumulation and time-dependent depuration of radioactive (63)Ni by the byssus, gut, foot, gills, kidney, adductor muscle and faeces of Mytilus edulis has been investigated using a pulse-chase technique. The rate and extent of depuration of (63)Ni varied between tissues and, after 168 h, the concentration factors and assimilation efficiencies ranged from 1 to 35 L kg(-1) and 5%-13%, respectively. Mussels were also exposed to a range of environmentally-realistic concentrations of dissolved Ni, prior to the analysis of biological endpoints. The clearance rate was concentration-dependent and at the highest concentration decreased by 30%. Neutral red retention (NRR) assays indicated a cytotoxic response and DNA strand breaks were observed in the haemocytes. The association of DNA damage with that of physiological and cytotoxic effects suggests that Ni exerts a significant impact on Mytilus edulis at cellular and genetic levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Genotoxic potential and heart rate disorders in the Mediterranean mussel Mytilus galloprovincialis exposed to Superdispersant-25 and dispersed diesel oil.

PubMed

Martinović, Rajko; Kolarević, Stoimir; Kračun-Kolarević, Margareta; Kostić, Jovana; Marković, Sandra; Gačić, Zoran; Kljajić, Zoran; Vuković-Gačić, Branka

2015-07-01

The effects of ex situ exposure of Mytilus galloprovincialis to Superdispersant-25 (S-25), diesel oil and dispersed diesel oil mixtures were studied by the impact on level of DNA damage in haemocytes (comet assay) and the cardiac activity patterns of mussels. Specimens were exposed for 72 h in a static system to diesel oil (100 μL/L and 1 mL/L), S-25 (5 and 50 μL/L), and dispersed diesel oil mixtures M1 (diesel oil 100 μL/L + S-25 5 μL/L) and M2 (diesel oil 1 mL/L + S-25 50 μL/L). For positive control 40 μM CdCl2 was used. The comet assay results indicated genotoxic potential of S-25 while the effects of diesel oil alone were not observed. The highest response was detected for M1 while the effects of M2 were not detected. The heart rate disorders were recorded for the diesel oil (1 mL/L), S-25 (50 μL/L) and both dispersed diesel oil mixtures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of 1,3-1,6 β-Glucan on Natural and Experimental Deformed Wing Virus Infection in Newly Emerged Honeybees (Apis mellifera ligustica)

PubMed Central

Sagona, Simona; Carrozza, Maria Luisa; Forzan, Mario; Pizzurro, Federica; Bibbiani, Carlo; Miragliotta, Vincenzo; Abramo, Francesca; Millanta, Francesca; Bagliacca, Marco; Poli, Alessandro; Felicioli, Antonio

2016-01-01

The Western Honeybee is a key pollinator for natural as well as agricultural ecosystems. In the last decade massive honeybee colony losses have been observed worldwide, the result of a complex syndrome triggered by multiple stress factors, with the RNA virus Deformed Wing Virus (DWV) and the mite Varroa destructor playing crucial roles. The mite supports replication of DWV to high titers, which exert an immunosuppressive action and correlate with the onset of the disease. The aim of this study was to investigate the effect of 1,3–1,6 β-glucan, a natural innate immune system modulator, on honeybee response to low-titer natural and high-titer experimental DWV infection. As the effects exerted by ß-glucans can be remarkably different, depending on the target organism and the dose administered, two parallel experiments were performed, where 1,3–1,6 ß-glucan at a concentration of 0.5% and 2% respectively, was added to the diet of three cohorts of newly emerged honeybees, which were sampled from a Varroa-free apiary and harboured a low endogenous DWV viral titer. Each cohort was subjected to one of the following experimental treatments: no injection, injection of a high-copy number DWV suspension into the haemocel (experimental DWV infection) or injection of PBS into the haemocoel (physical injury). Control bees fed a ß-glucan-free diet were subjected to the same treatments. Viral load, survival rate, haemocyte populations and phenoloxidase activity of each experimental group were measured and compared. The results indicated that oral administration of 0.5% ß-glucan to naturally infected honeybees was associated with a significantly decrease of the number of infected bees and viral load they carried, and with a significant increase of the survival rate, suggesting that this natural immune modulator molecule might contribute to increase honeybee resistance to viral infection. PMID:27829027

Effectiveness of Photodynamic Therapy for the Inactivation of Candida spp. on Dentures: In Vitro Study

PubMed Central

Mima, Ewerton Garcia de Oliveira; Ribeiro, Daniela Garcia; Dovigo, Livia Nordi; Vergani, Carlos Eduardo; Bagnato, Vanderlei Salvador

2011-01-01

Abstract Objective: This in vitro study evaluated the effectiveness of photodynamic therapy (PDT) for the inactivation of different species of Candida on maxillary complete dentures. Background data: The treatment of denture stomatitis requires the inactivation of Candida spp. on dentures. PDT has been reported as an effective method for Candida inactivation. Methods: Reference strains of C. albicans, C. glabrata, C. tropicalis, C. dubliniensis and C. krusei were tested. Thirty-four dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated with one of the strains and incubated at 37°C for 24 h. Dentures submitted to PDT (P+L+) were individually sprayed with 50 mg/L of Photogem® (PS) and, after 30 min, illuminated by LED light for 26 min (37.5 J/cm2). Additional dentures were treated only with PS (P+L-) or light (P-L+) or neither (P-L-). Samples of serial dilutions were spread on Sabouraud dextrose agar and incubated at 37°C for 48 h. The colonies were counted and the values of log (cfu/mL) were analyzed by Kruskall-Wallis and Dunn tests (p<0.05). Results: For all species of Candida, PDT resulted in significant reduction (p<0.05) of cfu/mL values from dentures when compared with P-L- (reductions from 1.73 to 3.99 log10). Significant differences (p<0.05), but lower reductions, were also observed for P+L- and P-L+when compared with P-L- for some species of Candida. Conclusions: PDT was an effective method for reducing Candida spp. on dentures. PMID:21916614

An in vitro study on the anti-adherence effect of Brucea javanica and Piper betle extracts towards oral Candida.

PubMed

Nordin, Mohd-Al-Faisal; Wan Harun, Wan Himratul Aznita; Abdul Razak, Fathilah

2013-10-01

The adherence of Candida to mucosal surfaces is the initial step for successful invasive process of the oral cavity. The study aimed to investigate the effect of two plant extracts on the non-specific and specific bindings of oral candida. In the former, adsorption to hexadecane was used to measure the hydrophobic interaction of the candida cells. In the later, glass beads coated with saliva represented the experimental pellicles in specific adhesion of oral candida to hard tissue surface. Candida krusei, Candida dubliniensis and Candida tropicalis showed the highest adsorption to hexadecane at 30.23%, 26.19% and 19.70%, respectively, while the others within the range of 7-10%. All candidal species were significantly affected by the extracts (P<0.05) with Brucea javanica exhibited more than 60% reduction of CSH than Piper betle. Candida parapsilosis showed the highest affinity in specific-bindings to pellicle with 18.72±0.71×10(5)CFU/ml. Exposing to P. betle-treated pellicle has drastically reduced the adherence of C. tropicalis, Candida albicans and C. krusei by 86.01%, 61.41% and 56.34%, respectively. B. javanica exhibited similar effect on C. tropicalis (89.86%), Candida lusitaniae (88.95%), C. albicans (79.74%), Candida glabrata (76.85%) and C. krusei (67.61%). The extracts demonstrated anti-adherence activities by modifying the CSH and the characteristics of the experimental pellicle. Copyright © 2013 Elsevier Ltd. All rights reserved.

Next-generation sequencing offers new insights into the resistance of Candida spp. to echinocandins and azoles.

PubMed

Garnaud, Cécile; Botterel, Françoise; Sertour, Natacha; Bougnoux, Marie-Elisabeth; Dannaoui, Eric; Larrat, Sylvie; Hennequin, Christophe; Guinea, Jesus; Cornet, Muriel; Maubon, Danièle

2015-09-01

MDR Candida strains are emerging. Next-generation sequencing (NGS), which enables extensive and deep genome analysis, was used to investigate echinocandin and azole resistance in clinical Candida isolates. Six genes commonly involved in antifungal resistance (ERG11, ERG3, TAC1, CgPDR1, FKS1 and FKS2) were analysed using NGS in 40 Candida isolates (18 Candida albicans, 15 Candida glabrata and 7 Candida parapsilosis). The strategy was validated using strains with known sequences. Then, 8 clinical strains displaying antifungal resistance and 23 sequential isolates collected from 10 patients receiving antifungal therapy were analysed. A total of 391 SNPs were detected, among which 6 coding SNPs were reported for the first time. Novel genetic alterations were detected in both azole and echinocandin resistance genes. A C. glabrata strain, which was resistant to echinocandins but highly susceptible to azoles, harboured an FKS2 S663P mutation plus a novel presumed loss-of-function CgPDR1 mutation. This isolate was from a patient with deep-seated and urinary candidiasis. Another C. glabrata isolate, with an MDR phenotype, carried a new FKS2 S663A mutation and a new putative gain-of-function CgPDR1 mutation (T370I); this isolate showed mutated (80%) and WT (20%) populations and was collected after 75 days of exposure to caspofungin from a patient who underwent complicated abdominal surgery. This study shows that NGS can be used for extensive assessment of genetic mutations involved in antifungal resistance. This type of wide genome approach will become very valuable for detecting mechanisms of resistance in clinical strains subjected to multidrug pressure. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Genetic variability and molecular identification of Brazilian Biomphalaria species (Mollusca: Planorbidae).

PubMed

Carvalho, S; Caldeira, R L; Simpson, A J; Vidigal, T H

2001-01-01

Freshwater snails belonging to the genus Biomphalaria are intermediate hosts of the trematode Schistosoma mansoni in the Neotropical region and Africa. In Brazil, one subspecies and ten species of Biomphalaria have been identified: B. glabrata, B. tenagophila, B. straminea, B. occidentalis, B. peregrina, B. kuhniana, B. schrammi, B. amazonica, B. oligoza, B. intermedia and B.t. guaibensis. However, only the first three species are found naturally infected with S. mansoni. The classical identification of these planorbids is based on comparison of morphological characteristics of the shell and male and female reproductive organs, which is greatly complicated by the extensive intra-specific variation. Several molecular techniques have been used in studies on the identification, genetic structure as well as phylogenetic relationships between these groups of organisms. Using the randomly amplified polymorphic DNAs (RAPD) analysis we demonstrated that B. glabrata exhibits a remarkable degree of intra-specific polymorphism. Thus, the genetics of the snail host may be more important to the epidemiology of schistosomiasis than those of the parasite itself. Using the simple sequence repeat anchored polymerase chain reaction (SSR-PCR) in intra-populational and intra-specific studies we have demonstrated that snails belonging to the B. straminea complex (B. straminea, B. kuhniana and B. intermedia) clearly presented higher heterogeneity. Using the low stringency polymerase chain reaction (LS-PCR) technique we were able to separate B. glabrata from B. tenagophila and B. tenagophila from B. occidentalis. To separate all Brazilian Biomphalaria species we used the restriction fragment length polymorphism (PCR-RFLP) of the internal transcribed spacer region (ITS) of the DNA gene. The method also proved to be efficient for the specific identification of DNA extracted from snail eggs. Recently we have sequenced the ITS2 region for phylogenetic studies of all Biomphalaria snails from

Species distribution and susceptibility profile to fluconazole, voriconazole and MXP-4509 of 551 clinical yeast isolates from a Romanian multi-centre study.

PubMed

Minea, B; Nastasa, V; Moraru, R F; Kolecka, A; Flonta, M M; Marincu, I; Man, A; Toma, F; Lupse, M; Doroftei, B; Marangoci, N; Pinteala, M; Boekhout, T; Mares, M

2015-02-01

This is the first multi-centre study regarding yeast infections in Romania. The aim was to determine the aetiological spectrum and susceptibility pattern to fluconazole, voriconazole and the novel compound MXP-4509. The 551 isolates were identified using routine laboratory methods, matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and DNA sequence analysis. Susceptibility testing was performed using the European Committee for Antimicrobial Susceptibility Testing (EUCAST) method and breakpoints. The yeasts originated from superficial infections (SUP, 51.5 %), bloodstream infections (BSI, 31.6 %) and deep-seated infections (DEEP, 16.9 %), from patients of all ages. Nine genera and 30 species were identified. The 20 Candida species accounted for 94.6 % of all isolates. C. albicans was the overall leading pathogen (50.5 %). Lodderomyces elongisporus is reported for the first time as a fungaemia cause in Europe. C. glabrata and Saccharomyces cerevisiae, as well as the non-Candida spp. and non-albicans Candida spp. groups, showed decreased fluconazole susceptibility (<75 %). The overall fluconazole resistance was 10.2 %. C. krusei accounted for 27 of the 56 fluconazole-resistant isolates. The overall voriconazole resistance was 2.5 % and was due mainly to C. glabrata and C. tropicalis isolates. Fluconazole resistance rates for the three categories of infection were similar to the overall value; voriconazole resistance rates differed: 4 % for BSI, 3.2 % for DEEP and 1.4 % for SUP. The antifungal activity of MXP-4509 was superior to voriconazole against C. glabrata and many fluconazole-resistant isolates. There was a large percentage of non-albicans Candida isolates. A large part of the high fluconazole resistance was not acquired but intrinsic, resulting from the high percentage of C. krusei.

Evaluation of esterase and hemolysin activities of different Candida species isolated from vulvovaginitis cases in Lorestan Province, Iran

PubMed Central

Noori, Maryam; Dakhili, Mohammad; Sepahvand, Asghar; Davari, Nader

2017-01-01

Background and Purpose: Annually affecting millions of women, vulvovaginal candidiasis (VVC) is commonly described by signs and symptoms of vulvovaginal inflammation in the presence of Candida species. Today, the detection of the virulence factors plays a major role in the understanding of pathogenesis of candidiasis and helps produce new anticandidial drugs to improve its treatment efficiency. Herein, we aimed to evaluate the esterase and hemolysin activities of the vaginal isolates of Candida and their relationship with the presence of VVC. Materials and Methods: One-hundred vaginal clinical specimens were randomly collected during September-December 2016. The target population consisted of married women suspected of VVC who presented to health centers in Lorestan Province, Iran. In this study, the esterase activity and hemolysin production of Candida clinical isolates were evaluated using the Tween 80 opacity test and the plate assay, respectively. Results: The most frequent Candida species was C. albicans (66; 66%), followed by C. glabrata (11; 11%) and C. tropicalis (11; 11%). The highest esterase activity was found in C. krusei (75%), followed by C. albicans (68.2%) and C. glabrata (54.5%). The greater part of the positive esterase isolates had Pz 4+ scores. Among the Candida species, C. albicans (22.7%), C. glabrata (63.6%), and C. krusei (50%) were found to have the highest rates of alpha, beta, and gamma hemolysin production, respectively. The level of hemolytic activity in 51% of the Candida species was Pz 4+ scores. Conclusion: According to our results, the higher expression rates of both enzymes in C. albicans species relative to those of non-albicans Candidate species can partly reflect the role of the virulence factors involved in C. albicans pathogenicity. PMID:29707672

Cloning and characterisation of cDNA sequences encoding for anti-lipopolysaccharide factors (ALFs) in Brazilian palaemonid and penaeid shrimps.

PubMed

Rosa, Rafael Diego; Stoco, Patricia Hermes; Barracco, Margherita Anna

2008-11-01

Anti-lipopolysaccharide factors (ALFs) are antimicrobial peptides found in limulids and crustaceans that have a potent and broad range of antimicrobial activity. We report here the identification and molecular characterisation of new sequences encoding for ALFs in the haemocytes of the freshwater prawn Macrobrachium olfersi and also in two Brazilian penaeid species, Farfantepenaeus paulensis and Litopenaeus schmitti. All obtained sequences encoded for highly cationic peptides containing two conserved cysteine residues flanking a putative LPS-binding domain. They exhibited a significant amino acid similarity with crustacean and limulid ALF sequences, especially with those of penaeid shrimps. This is the first identification of ALF in a freshwater prawn.

Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay.

PubMed

Praveen Kumar, M K; Shyama, S K; Sonaye, B S; Naik, U Roshini; Kadam, S B; Bipin, P D; D'costa, A; Chaubey, R C

2014-05-01

Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of 'Comet assay' for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in both bivalve species. This showed a dose-dependent increase of genetic damage induced in bivalves by EMS as well as gamma radiation. Further, the highest DNA damage was observed at 24h. The damage gradually decreased with time, i.e. was smaller at 48 and 72 h than at 24h post irradiation in both species of bivalves. This may indicate repair of the damaged DNA and/or loss of heavily damaged cells as the post irradiation time advanced. The present study

Normal yeast flora of the upper digestive tract of some wild columbids

USGS Publications Warehouse

Kocan, R.M.; Hasenclever, H.F.

1972-01-01

Seven species of pigeons and doves were cultured for yeasts in the upper digestive tract. The following list gives the isolation rate for each columbid species and the yeasts cultured from them: feral pigeon Columba Livia (Gmelin) 95% -Candida albicans (Robin) Berkhout, C. tropicalis (Castellani) Berkhout, C. krusei (Cast.) Berkhout, C. guilliermondii (Cast.) Langeron et Guerra, Torulopsis glabrata (Anderson) Lodder et De Vries, Saccharomyces telluris Van der Walt, and Geotrichum sp.; white-crowned pigeon (C. leucocephala Linnaeus) 56% -- S. telluris; mourning dove (Zenaidura rnacroura Linnaeus) 24% -- C. albicans, C. tropicalis, C. guilliermondii, and Geotrichurn sp.; passerine ground dove (Collumbigallina passerina Linnaeus) 20% -- C. parapsilosis (Ashford) Langeron et Talice, Kloeckera apiculata (Reess Emend. Klocker) Janke; zenaida dove (Zenaida aurita Temminck) 16% -- C. albicans, C. guilliermondii, and T. glabrata; one moustasche dove (Geotrygon mystacea Gosse) -- C. guillierrnondii; ringed turtle dove (Streptopelia rizoria Linnaeus) 14% -- C. albicans and Geotrichurn sp. No signs of disease could be seen in the 139 birds that were examined, and it was concluded that these yeasts comprise a part of the columbid's normal microbial flora.

Return to Glacier Bay

USGS Publications Warehouse

Bodkin, James L.

2003-01-01

Seven species of pigeons and doves were cultured for yeasts in the upper digestive tract. The following list gives the isolation rate for each columbid species and the yeasts cultured from them: feral pigeon Columba Livia (Gmelin) 95% -Candida albicans (Robin) Berkhout, C. tropicalis (Castellani) Berkhout, C. krusei (Cast.) Berkhout, C. guilliermondii (Cast.) Langeron et Guerra, Torulopsis glabrata (Anderson) Lodder et De Vries, Saccharomyces telluris Van der Walt, and Geotrichum sp.; white-crowned pigeon (C. leucocephala Linnaeus) 56% -- S. telluris; mourning dove (Zenaidura rnacroura Linnaeus) 24% -- C. albicans, C. tropicalis, C. guilliermondii, and Geotrichurn sp.; passerine ground dove (Collumbigallina passerina Linnaeus) 20% -- C. parapsilosis (Ashford) Langeron et Talice, Kloeckera apiculata (Reess Emend. Klocker) Janke; zenaida dove (Zenaida aurita Temminck) 16% -- C. albicans, C. guilliermondii, and T. glabrata; one moustasche dove (Geotrygon mystacea Gosse) -- C. guillierrnondii; ringed turtle dove (Streptopelia rizoria Linnaeus) 14% -- C. albicans and Geotrichurn sp. No signs of disease could be seen in the 139 birds that were examined, and it was concluded that these yeasts comprise a part of the columbid's normal microbial flora.

Structure and Mechanism of a Eukaryotic FMN Adenylyltransferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huerta, Carlos; Borek, Dominika; Machius, Mischa

2009-12-01

Flavin mononucleotide adenylyltransferase (FMNAT) catalyzes the formation of the essential flavocoenzyme flavin adenine dinucleotide (FAD) and plays an important role in flavocoenzyme homeostasis regulation. By sequence comparison, bacterial and eukaryotic FMNAT enzymes belong to two different protein superfamilies and apparently utilize different sets of active-site residues to accomplish the same chemistry. Here we report the first structural characterization of a eukaryotic FMNAT from the pathogenic yeast Candida glabrata. Four crystal structures of C. glabrata FMNAT in different complexed forms were determined at 1.20-1.95 A resolutions, capturing the enzyme active-site states prior to and after catalysis. These structures reveal a novelmore » flavin-binding mode and a unique enzyme-bound FAD conformation. Comparison of the bacterial and eukaryotic FMNATs provides a structural basis for understanding the convergent evolution of the same FMNAT activity from different protein ancestors. Structure-based investigation of the kinetic properties of FMNAT should offer insights into the regulatory mechanisms of FAD homeostasis by FMNAT in eukaryotic organisms.« less

Rapid Identification of Candida Species by Using Nuclear Magnetic Resonance Spectroscopy and a Statistical Classification Strategy

PubMed Central

Himmelreich, Uwe; Somorjai, Ray L.; Dolenko, Brion; Lee, Ok Cha; Daniel, Heide-Marie; Murray, Ronan; Mountford, Carolyn E.; Sorrell, Tania C.

2003-01-01

Nuclear magnetic resonance (NMR) spectra were acquired from suspensions of clinically important yeast species of the genus Candida to characterize the relationship between metabolite profiles and species identification. Major metabolites were identified by using two-dimensional correlation NMR spectroscopy. One-dimensional proton NMR spectra were analyzed by using a staged statistical classification strategy. Analysis of NMR spectra from 442 isolates of Candida albicans, C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis resulted in rapid, accurate identification when compared with conventional and DNA-based identification. Spectral regions used for the classification of the five yeast species revealed species-specific differences in relative amounts of lipids, trehalose, polyols, and other metabolites. Isolates of C. parapsilosis and C. glabrata with unusual PCR fingerprinting patterns also generated atypical NMR spectra, suggesting the possibility of intraspecies discontinuity. We conclude that NMR spectroscopy combined with a statistical classification strategy is a rapid, nondestructive, and potentially valuable method for identification and chemotaxonomic characterization that may be broadly applicable to fungi and other microorganisms. PMID:12902244

Vaginal nystatin versus oral fluconazole for the treatment for recurrent vulvovaginal candidiasis.

PubMed

Fan, Shangrong; Liu, Xiaoping; Wu, Cong; Xu, Lixuan; Li, Jianling

2015-02-01

Recurrent vulvovaginal candidiasis (RVVC) is a common condition that can physically and psychologically impact patients. We compared the efficacy and safety of vaginal nystatin suppositories for 14 days each month versus standard oral fluconazole regimens for the treatment for RVVC. Patients (n = 293) were enrolled in the study from April 2010 to September 2013. After the initial therapy, the mycological cure rates were 78.3% (119/152) and 73.8% (104/141) in the nystatin group and fluconazole group, respectively (95% CI, 0.749-2.197, p > 0.05). The mycological cure rates at the end of maintenance therapy were 80.7% (96/119) and 72.7% (72/99) in the two groups, respectively (95% CI, 0.954-3.293, p > 0.05).The mycological cure rates at the end without treatment for 6 months were 81.25% (78/96) and 82.19% (60/73) in the two groups, respectively (95% CI, 0.427-2.066, p > 0.05). The mycological cure rates of RVVC caused by C. albicans were 84.0% (89/106) and 81.8% (99/121) in the two groups, respectively. The mycological cure rates of RVVC caused by C. glabrata were 64.3% (27/42) and 12.5% (2/16) in the two groups, respectively. The initial and 6-month maintenance therapy were successful in five of the nine patients in the nystatin group with RVVC caused by fluconazole-resistant Candida, whereas in the fluconazole group, initial therapy failed in all patients with RVVC caused by fluconazole-resistant Candida (n = 7). We conclude that both fluconazole and nystatin therapies are effective in treating RVVC. Nystatin may also be effective for the treatment for RVVC caused by C. glabrata or fluconazole-resistant Candida.

Nicotinic acid, nicotinamide, and nicotinamide riboside: a molecular evaluation of NAD+ precursor vitamins in human nutrition.

PubMed

Bogan, Katrina L; Brenner, Charles

2008-01-01

Although baseline requirements for nicotinamide adenine dinucleotide (NAD+) synthesis can be met either with dietary tryptophan or with less than 20 mg of daily niacin, which consists of nicotinic acid and/or nicotinamide, there is growing evidence that substantially greater rates of NAD+ synthesis may be beneficial to protect against neurological degeneration, Candida glabrata infection, and possibly to enhance reverse cholesterol transport. The distinct and tissue-specific biosynthetic and/or ligand activities of tryptophan, nicotinic acid, nicotinamide, and the newly identified NAD+ precursor, nicotinamide riboside, reviewed herein, are responsible for vitamin-specific effects and side effects. Because current data suggest that nicotinamide riboside may be the only vitamin precursor that supports neuronal NAD+ synthesis, we present prospects for human nicotinamide riboside supplementation and propose areas for future research.

Effects of ashes from a Brazilian savanna wildfire on water, soil and biota: An ecotoxicological approach.

PubMed

Oliveira-Filho, Eduardo C; Brito, Darlan Q; Dias, Zelia M B; Guarieiro, Mayara S; Carvalho, Esther L; Fascineli, Maria L; Niva, Cintia C; Grisolia, Cesar K

2018-03-15

Wildfire is very common in Brazilian savannas, and its effects on water, soil and aquatic/soil organisms are poorly understood. In this study, we observed the effects of fire, especially of ashes, on surface soil and subsurface water in a typical Brazilian savanna (Cerrado sensu strictu) for one year. Soil analyses (pH, organic matter content, potential acidity, K, Ca, Mg and P) and subsurface water analyses (NO 3- , PO 4 3- Mg 2+ , Ca 2+ and K + ) were assessed. We evaluated the ecotoxicological effects of ashes on three different endpoints and species, in fish Danio rerio (embryonic development), aquatic snail Biomphalaria glabrata (reproduction) and a soil species Enchytraeus sp. (reproduction). We found a higher amount of exchangeable cations and organic matter content in short-term fire effects on soil, but the higher availability of nutrients did not affect the soil pH in field plots. The effects of ashes on soil and subsurface water did not persist for one-year post-fire, except for organic matter content in burned areas. No toxic effects were observed on hatching success and incidences of developmental abnormalities in D. rerio embryos. However, ash input had adverse effects on reproduction in snails and enchytraeids. We reported a statistically significant decrease in snail eggs exposed to the 50g.L -1 and 100g.L -1 of ashes after four weeks (p<0.05, Dunnett's test and Tukey test). Enchytraeus sp. reproduction was negatively influenced by the natural soil, which presents high acidity, and also when exposed directly to the ashes from burned area, suggesting that pH and other ash compounds may limit the growth of enchytraeids. More studies in burned areas are strongly encouraged, addressing the potential important routes of exposure to ashes in order to understand the impact of intense fires on soil and aquatic biota in tropical savannas. Copyright © 2017 Elsevier B.V. All rights reserved.

[In vitro synergistic effect of moxifloxacin and amphotericin B combination against Candida strains].

PubMed

Yalçin, Burçe; Kalkanci, Ayşe; Gürelik, Feryal; Fidan, Işil; Kustimur, Semra; Ozdek, Sengül

2010-01-01

Contradictory results such as synergy or indifferent effect, have been reported about the interactions between quinolones and antifungal drugs in different studies. The aim of this study was to investigate the in vitro susceptibilities of Candida spp. to moxifloxacin (MOX) alone and MOX + amphotericin B (AmB) combination. A total of 20 strains were included to the study, of which 19 were clinical isolates (10 Candida albicans, 4 Candida glabrata, 2 Candida parapsilosis, 1 Candida tropicalis, 1 Candida pelliculosa ve 1 Candida sake) and 1 was a standard strain (C. albicans ATCC 90028). In vitro susceptibilities of the strains to MOX with AmB were investigated by broth microdilution method according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI), and in vitro interaction of these drugs were determined by a chequerboard titration method. Minimal inhibitory concentration (MIC) values of Candida spp. for MOX were found > or = 400 microg/ml indicating that MOX, by itself has no antifungal activity. AmB MIC values were found 1 microg/ml in 11 of the clinical isolates, and < or = 0.5 microg/ml in the other 8 clinical isolates and 1 standard strain. The inhibitor activity of AmB was slightly enhanced when combined with MOX, there being a decrease of 1-4 fold dilutions in the AmB MICs against all isolates tested. Synergistic effect between MOX and AmB, defined as a fractional inhibitory concentration (FIC) index as < or = 0.5, was observed in 90% (18/20; all were clinical isolates) of the strains, whereas indifferent effect (FIC = 1) was detected in 10% (2/20; 1 was clinical and 1 was standard strain) of the strains. Antagonistic effect was not observed for this combination even at 48th hours. It was concluded that these preliminary results should be confirmed by large-scaled in vitro and in vivo studies to evaluate MOX + AmB combination as a therapeutic option for the treatment of Candida infections.

Long-term consequences of a short-term hypergravity load in a snail model

NASA Astrophysics Data System (ADS)

Martynova, Marina G.; Shabelnikov, Sergej V.; Bystrova, Olga A.

2015-07-01

Here we focused on the dynamic processes in the snail at different time after short-term hypergravity load (STHL) by monitoring the state of neuroendocrine and immune systems, the nucleic acid synthesis levels in the atrial cells, and the behaviour of the atrial granular cells (GCs). We observed that immediately after centrifugation (14 g for 15 min) in the snail haemolymph concentration of dopamine and noradrenaline (measured by high-performance liquid chromatography) and the number of circulating haemocytes and their proliferative activity (estimated by the direct cell counting and [3H]thymidine incorporation, respectively) increased significantly, whereas the concentration of adrenaline decreased. Twenty-four hours after STHL, the levels of catecholamines and haemocytes returned to their control values. In the atrial epicardial and endothelial cells, a notable drop of transcription activity (evaluated by [3H]uridine autoradiography) from the baseline in the immediate post-STHL period was followed by its gradual increase reaching a maximum at the day 5 and subsequent decrease to control value by the day 10. In endothelial cells, DNA-synthesizing activity (evaluated by [3H]thymidine autoradiography) equal to zero before and just after STHL, increased significantly at the day 5, and decreased by the day 10. The atrial GCs underwent total degranulation. Formed as a result small ungranulated cells exhibited DNA synthesis. Afterwards, most probably, the GCs divided and regranulated. One month after STHL the GC population had been restored. Overall, STHL has triggered an immediate reaction of the neuroendocrine and immune systems and initiated long-lasting processes at a cellular level, which included alterations in activity of nucleic acid syntheses in the epicardial and endothelial cells and remodelling of the GC population in the atrium.

The efficacy of Poly-β-Hydroxy Butyrate (PHB)/biosurfactant derived from Staphylococcus hominis against White Spot Syndrome Virus (WSSV) in Penaeus monodon.

PubMed

Monica, M; Priyanka, T; Akshaya, Murugesan; Rajeswari, V; Sivakumar, Lingappa; Somasundaram, S T; Shenbhagarathai, R

2017-12-01

White Spot Syndrome Virus (WSSV) is one of the most important causative agents of Penaeid shrimps diseases that incur heavy losses to the shrimp aquaculture. It has severe impact on the sustainability and the production of Penaeus monodon. Hence, the present study focussed on the investigation of Poly-β-hydroxybutyrate/biosurfactant as immunostimulants against WSSV infected shrimps. Infection of WSSV was periodically checked in all the experimental shrimps using PCR diagnostic kit. After ensuring all shrimps were free of viral infection, experiments were carried out to analyze the nonspecific immune responses (prophenol oxidase, nitro blue tetrazolium reduction assay and total haemocyte count) both in control and experimental group. Further, gills and muscles of Penaeus monodon were subjected to proteome analysis after treated it with PHB/biosurfactant independently in the concentration of 2% and 5% each. Increase in the level of haemocytes was observed in both PHB (26 ± 2 × 10⁴ cells)/biosurfactant (28 ± 2 × 10 4  cells) treated shrimps, when compared with control (17 ± 2 × 10⁴ cells). proPhenolOxidase (proPO) activity was also enhanced in treated groups compared to WSSV infected shrimps. Less production of superoxide anion was observed in control and treated groups. Differences in the protein expression was analyzed in muscle tissue of control, WSSV infected and PHB/biosurfactant treated shrimps. Our finding suggested that partial substitution of feed with 2% PHB and biosurfactant showed increased rate on the survival of WSSV infected P. monodon which might be due to either the over expression/down regulation of proteins that play a vital role in enhancing the immune system/the progression of the disease respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

The role of pilin protein of Xenorhabdus nematophila against immune defense reactions of insects.

PubMed

Darsouei, Reyhaneh; Karimi, Javad; Dunphy, Gary B

2017-08-01

Xenorhabdus nematophila is a symbiotic bacterium of the entomopathogenic nematode Steinernema carpocapsae (Weiser). It produces several toxic proteins which interfere with the immune system of insects. The current study shows that purified pilin protein could be a virulence trait of X. nematophila. The fifth instar larvae of Spodoptera exigua (Hübner) was injected with purified pilin. Changes in the cellular defenses in terms of total haemocyte counts and granulocyte percentage and humoral factors including total protease, phospholipase A 2 , and phenoloxidase activities (humoral defense) as well as the expression of the three main antimicrobial peptides attacin, cecropin, and spodoptericin were measured at specific times. The level of THC and granulocytes in larvae with different concentrations of pilin protein were less than the negative control. Also agglutination of haemocytes was observed 8-16h post-injection. The pilin protein activated phenoloxidase in the initial hour post-injection, by 2hpi, activity was stable. The activities of phospholipase A2 and protease activities reached maximum levels at 12 and 4hpi, respectively, and then decreased. The expressions of attacin, cecropin, and spodoptericin in larvae treated with pilin protein were up-regulated above that of the normal sample. The overexpression of cecropin was greater than the other antimicrobial protein mRNA transcripts. The spodoptericin expression had an irregular trend while expressions of attacin and cecropin reached maximum levels at 4hpi and then decreased. Generally, after the injection of pilin protein, the cellular and humoral immune system of S. exigua is activated but this toxin was able to inhibit them. This is the first report of the role of pilin protein when the bacterial symbiont of S. carpocapsae encounters the humoral defense of an insect. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

White shrimp Litopenaeus vannamei that have received fucoidan exhibit a defense against Vibrio alginolyticus and WSSV despite their recovery of immune parameters to background levels.

PubMed

Chen, Yu-Yuan; Kitikiew, Suwaree; Yeh, Su-Tuen; Chen, Jiann-Chu

2016-12-01

White shrimp Litopenaeus vannamei receiving fucoidan at 2, 6, and 10 μg g -1 after 0-144 h or 0-120 h were examined for immune parameters (haemograms, phenoloxidase activity, respiratory burst, and superoxide dismutase activity), proliferation of haemocyte in the haematopoietic tissue (HPT), gene expression, and phagocytic activity and clearance efficiency to Vibrio alginolyticus. Immune parameters and mitotic index of HPT increased after 3-24 h, reached their maxima after 48-72 h, and returned to background values after 144 h. Transcripts of lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PX), prophenoloxidase (proPO) I, proPO II, astakine, and haemocyte homeostasis-associated protein (HHAP) were up-regulated to a maximum after 48-72 h and returned to background values after 144 h. Phagocytic activity and clearance efficiency to V. alginolyticus increased after 12 h, reached its maximum after 48 h, and continued to remain higher after 120 h. In another experiment, shrimp receiving fucoidan after 48 h and 144 h were respectively challenged with V. alinolyticus at 6 × 10 6  colony-forming units (cfu) shrimp -1 or challenged with WSSV at 1.2 × 10 5  copies shrimp -1 and then placed in seawater. The survival rate of shrimp receiving fucoidan was significantly higher than in controls. In conclusion, shrimp receiving fucoidan showed a proliferation of HPT, increased immune parameters, and up-regulated transcripts of LGBP, PX, proPO I, proPO II, astakine, and HHAP after 48 h. Shrimp receiving fucoidan exhibited a defense against V. alginolyticus and WSSV, even after immune parameters recovered to background levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Evaluation of PNA-FISH method for direct identification of Candida species in blood culture samples and its potential impact on guidance of antifungal therapy].

PubMed

Doğan, Özlem; İnkaya, Ahmet Çağkan; Gülmez, Dolunay; Uzun, Ömrüm; Akova, Murat; Arıkan Akdağlı, Sevtap

2016-10-01

Early antifungal therapy has a major influence on survival in candidemia. Rapid identification of the species has importance for the treatment, prediction of the species-specific primary resistance and variable antifungal susceptibility. Recently, molecular-based methods attempt to reduce the time between the positive signal of a blood culture and identification of the fungus. PNA-FISH (Peptide nucleic acid fluorescence in situ hybridization) assay distinguishes a number of frequently isolated Candida species in groups following the growth in blood culture. The aim of this study was to investigate the correlation of the species identified by PNA-FISH with conventional identification methods in yeast positive blood cultures and its influence on the selection of antifungal therapy. Specimens of adult patients diagnosed as yeast with Gram stain in signal-positive blood cultures between August to December 2013, were included in the study. The strains were concomitantly cultivated by subculturing from the blood culture bottles onto solid media and identified by conventional methods (germ tube test, ID32C and morphology on cornmeal Tween 80 agar). Rapid species identification was performed by Yeast Traffic Light PNA-FISH, which generates green flourescence for Candida albicans and Candida parapsilosis, yellow for Candida tropicalis, and red for Candida krusei and Candida glabrata. C.tropicalis was identified as a single species whereas the others were identified in pairs. The time points when the yeast positive blood culture bottle was received by the mycology laboratory and reporting of the species identification results by PNA-FISH and the conventional methods were recorded. Seven C.albicans, six C.glabrata, three C.parapsilosis, one C.tropicalis, one C.krusei, one Cryptococcus neoformans, one Saprochaete capitata (Blastoschizomyces capitatus), one C.albicans and Candida dubliniensis, one C.krusei and C.dubliniensis, and one C.glabrata and C.parapsilosis were

Facilitation of trace metal uptake in cells by inulin coating of metallic nanoparticles

NASA Astrophysics Data System (ADS)

Santillán-Urquiza, Esmeralda; Arteaga-Cardona, Fernando; Torres-Duarte, Cristina; Cole, Bryan; Wu, Bing; Méndez-Rojas, Miguel A.; Cherr, Gary N.

2017-09-01

Trace elements such as zinc and iron are essential for the proper function of biochemical processes, and their uptake and bioavailability are dependent on their chemical form. Supplementation of trace metals through nanostructured materials is a new field, but its application raises concerns regarding their toxicity. Here, we compared the intracellular zinc uptake of different sources of zinc: zinc sulfate, and ZnO and core-shell α-Fe2O3@ZnO nanoparticles, coated or uncoated with inulin, an edible and biocompatible polysaccharide. Using mussel haemocytes, a well-known model system to assess nanomaterial toxicity, we simultaneously assessed zinc accumulation and multiple cellular response endpoints. We found that intracellular zinc uptake was strongly enhanced by inulin coating, in comparison to the uncoated nanoparticles, while no significant effects on cell death, cell viability, mitochondrial membrane integrity, production of reactive oxygen species or lysosome abundance were observed at concentrations up to 20 ppm. Since no significant increments in toxicity were observed, the coated nanomaterials may be useful to increase in vivo zinc uptake for nutritional applications.

Laccase 1 gene from Plutella xylostella (PxLac1) and its functions in humoral immune response.

PubMed

Wang, Ze-Hua; Hu, Rong-Min; Ye, Xi-Qian; Huang, Jian-Hua; Chen, Xue-Xin; Shi, Min

Laccase (EC 1.10.3.2) is a phenoloxidase found in many insect species. The Laccase 1 gene from Plutella xylostella (PxLac1) was cloned, and its expression patterns and functions were determined using qPCR and RNAi methods. The results showed that the expression levels of PxLac1 were consistently high in all larval stages, and the most abundant was in the midgut during the 4th instar stage. Moreover, the expression of PxLac1 was up-regulated in response to bacterial infection, and decreased 24 h after being parasitized by Cotesia vestalis. Further analyses indicated that the effect of parasitization on PxLac1 was induced by active C. vestalis Bracovirus (CvBV). Haemocyte-free hemolymph phenoloxidase (PO) activity was suppressed when PxLac1 was treated with RNAi. Our results provide evidence for a connection between the Laccase 1 gene and insect immunity, and revealed that parasitoid polydnavirus suppresses host PO activity via PxLac1 regulation. Copyright © 2018. Published by Elsevier Ltd.

[In vitro antifungal resistance in Candida albicans from HIV-infected patients with and without oral candidosis.].

PubMed

Ceballos Salobreña, A; Gaitán Cepeda, L A; Orihuela Cañada, F; Olea Barrionuevo, D; Ceballos García, L; Quindós, G

1999-12-01

The main purpose of this study has been to determine the in vitro antifungal susceptibility of clinical isolates from HIV-infected or AIDS patients, depending on the presence of oral candidosis. The oral cavity of 307 HIV-infected or AIDS patients was examined and an oral swab was cultured on Sabouraud glucose agar and studied by conventional mycological methods. In vitro antifungal susceptibility to amphotericin B, nystatin, fluconazole, itraconazole and ketoconazole was tested by disk diffusion with Neo-Sensitabs tablets (Rosco Diagnostica, Dinamarca). One hundred and thirty five Candida albicans isolates (91 serotype A, 38 serotype B, three C. albicans variety stellatoidea and three untyped isolates), three Candida krusei and two Candida glabrata were obtained. All the isolates were susceptible to nystatin and amphotericin B. However, 7.9% isolates were resistant to fluconazole and 2.9% isolates were resistant to ketoconazole or itraconazole. Nearly all C. krusei and C. glabrata isolates, 31% patients with candidosis and 20% Candida-colonized patients showed decreased susceptibility to azoles. This study shows that polyenes had a great in vitro efficacy against clinical isolates from HIV-infected patients and that in vitro resistance to azoles is not as high as observed in other countries.

Peptides of the Constant Region of Antibodies Display Fungicidal Activity

PubMed Central

Polonelli, Luciano; Ciociola, Tecla; Magliani, Walter; Zanello, Pier Paolo; D'Adda, Tiziana; Galati, Serena; De Bernardis, Flavia; Arancia, Silvia; Gabrielli, Elena; Pericolini, Eva; Vecchiarelli, Anna; Arruda, Denise C.; Pinto, Marcia R.; Travassos, Luiz R.; Pertinhez, Thelma A.; Spisni, Alberto; Conti, Stefania

2012-01-01

Synthetic peptides with sequences identical to fragments of the constant region of different classes (IgG, IgM, IgA) of antibodies (Fc-peptides) exerted a fungicidal activity in vitro against pathogenic yeasts, such as Candida albicans, Candida glabrata, Cryptococcus neoformans, and Malassezia furfur, including caspofungin and triazole resistant strains. Alanine-substituted derivatives of fungicidal Fc-peptides, tested to evaluate the critical role of each residue, displayed unaltered, increased or decreased candidacidal activity in vitro. An Fc-peptide, included in all human IgGs, displayed a therapeutic effect against experimental mucosal and systemic candidiasis in mouse models. It is intriguing to hypothesize that some Fc-peptides may influence the antifungal immune response and constitute the basis for devising new antifungal agents. PMID:22470523

Anti-Candida activity of Mentha arvensis and Turnera ulmifolia.

PubMed

Santos, Karla K A; Matias, Edinardo F F; Souza, Celestina E S; Tintino, Saulo R; Braga, Maria F B M; Guedes, Glaucia M M; Nogueira, Lavouisier F B; Morais, Edson C; Costa, José G M; Menezes, Irwin R A; Coutinho, Henrique D M

2012-03-01

Candidiasis is the most frequent infection by opportunistic fungi, frequently caused by Candida albicans, Candida tropicalis, Candida parapsilosis, Candida glabrata, and Candida krusei. Mentha arvensis L. is a herbaceous plant that occurs throughout South America and is used as a tea and in the folk medicine. Turnera ulmifolia L. is already known to be of medicinal value. Ethanol extracts from M. arvensis and T. ulmifolia were assayed for antifungal activity against strains of C. albicans, C. tropicalis, and C. krusei. No clinically relevant antifungal activity was demonstrated by the extracts; however, a potentiation effect was observed when the extracts were applied with metronidazole against C. tropicalis. M. arvensis and T. ulmifolia could represent a source of natural products with modifying antifungal activity.

Oral Candida albicans isolates from HIV-positive individuals have similar in vitro biofilm-forming ability and pathogenicity as invasive Candida isolates

PubMed Central

2011-01-01

Background Candida can cause mucocutaneous and/or systemic infections in hospitalized and immunosuppressed patients. Most individuals are colonized by Candida spp. as part of the oral flora and the intestinal tract. We compared oral and systemic isolates for the capacity to form biofilm in an in vitro biofilm model and pathogenicity in the Galleria mellonella infection model. The oral Candida strains were isolated from the HIV patients and included species of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. krusei, C. norvegensis, and C. dubliniensis. The systemic strains were isolated from patients with invasive candidiasis and included species of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. lusitaniae, and C. kefyr. For each of the acquired strains, biofilm formation was evaluated on standardized samples of silicone pads and acrylic resin. We assessed the pathogenicity of the strains by infecting G. mellonella animals with Candida strains and observing survival. Results The biofilm formation and pathogenicity in Galleria was similar between oral and systemic isolates. The quantity of biofilm formed and the virulence in G. mellonella were different for each of the species studied. On silicone pads, C. albicans and C. dubliniensis produced more biofilm (1.12 to 6.61 mg) than the other species (0.25 to 3.66 mg). However, all Candida species produced a similar biofilm on acrylic resin, material used in dental prostheses. C. albicans, C. dubliniensis, C. tropicalis, and C. parapsilosis were the most virulent species in G. mellonella with 100% of mortality, followed by C. lusitaniae (87%), C. novergensis (37%), C. krusei (25%), C. glabrata (20%), and C. kefyr (12%). Conclusions We found that on silicone pads as well as in the Galleria model, biofilm formation and virulence depends on the Candida species. Importantly, for C. albicans the pathogenicity of oral Candida isolates was similar to systemic Candida isolates, suggesting that Candida

Species-specific prevalence of vaginal candidiasis among patients with diabetes mellitus and its relation to their glycaemic status.

PubMed

Goswami, R; Dadhwal, V; Tejaswi, S; Datta, K; Paul, A; Haricharan, R N; Banerjee, U; Kochupillai, N P

2000-09-01

Non- C. albicans Candida species are increasingly being recognized as the cause of vulvo-vaginal candidiasis. These species are often less susceptible to antifungal agents. Patients with diabetes mellitus are at risk for vulvo-vaginal candidasis. We assessed the species-specific prevalence rate and risk of candidiasis in patients with diabetes mellitus and healthy controls. Genital tract examination, direct microscopy and fungal cultures of discharge collected by high vaginal swab were undertaken among 78 consecutive patients with diabetes mellitus (mean (+/-sd) age 32+/-12 years and body mass index (BMI) 22.3+/-5.5kg/m(2)) and 88 age- and BMI-matched healthy females. Glycaemic control in the diabetic cohort was assessed by measuring total glycosylated haemoglobin. Candida species were isolated in 36 of 78 (46%) subjects with diabetes mellitus and in 21 of 88 (23%) healthy subjects (Chi-squared 9.11, P=0.0025). The predominant Candida species isolated in diabetics with vulvo-vaginal candidiasis were Candida glabrata (39%), C. albicans (26%) and C. tropicalis (17%). In contrast, in the control group, C. albicans, C. glabrata and C. hemulonii comprised 30% each, with none having C. tropicalis infection (for C. tropicalis: diabetic vs. control; 17% vs. nil, P=0. 05). Among the diabetic group, subjects with vulvo-vaginal candidiasis had significantly higher mean HbA1 when compared to those who had no such infection (12.8+/-2.6% vs. 9.7+/-1.7% respectively, P=0.001). The overall accuracy of direct microscopy and clinical examination for predicting vulvo-vaginal candidiasis was only 77% and 51%, respectively, in the diabetic group, and 83% and 65% in the control group. Patients with diabetes mellitus had a high prevalence rate (46%) of vulvo-vaginal candidiasis with relative risk of 2.45. The non- C. albicans species such as C. glabrata and C. tropicalis were the predominant species isolated among them. There seems to be a significant link between hyperglycaemia and

Role of tyrosol on Candida albicans, Candida glabrata and Streptococcus mutans biofilms developed on different surfaces.

PubMed

Monteiro, Douglas Roberto; Arias, Laís Salomão; Fernandes, Renan Aparecido; Straioto, Fabiana Gouveia; Barros Barbosa, Débora; Pessan, Juliano Pelim; Delbem, Alberto Carlos Botazzo

2017-02-01

To assess the effect of tyrosol on the production of hydrolytic enzymes (by Candida biofilm cells) and acid (by Streptococcus mutans biofilms), as well as to quantify single and mixed biofilms of these species formed on acrylic resin (AR) and hydroxyapatite (HA). Candida and S. mutans biofilms were formed on AR and HA in the presence of tyrosol during 48 hours. Next, acid proteinase, phospholipase and hemolytic activities of Candida biofilm cells were determined, while acid production by S. mutans biofilms was assessed by pH determination. The effect of tyrosol on mature biofilms (96 hours) was evaluated through quantification of total biomass, metabolic activity, number of colony-forming units and composition of biofilms' extracellular matrix. Data were analyzed by one- and two-way ANOVA, followed by Tukey's and Holm-Sidak's tests (α = 0.05). Treatments with tyrosol were not able to significantly reduce hydrolytic enzymes and acid production by Candida and S. mutans. Tyrosol only significantly reduced the metabolic activity of single biofilms of Candida species. Tyrosol on its own had a limited efficacy against single and mixed-species oral biofilms. Its use as an alternative antimicrobial for topical therapies still demands more investigation.

Influence of hyaluronic acid on bacterial and fungal species, including clinically relevant opportunistic pathogens.

PubMed

Ardizzoni, Andrea; Neglia, Rachele G; Baschieri, Maria C; Cermelli, Claudio; Caratozzolo, Manuela; Righi, Elena; Palmieri, Beniamino; Blasi, Elisabetta

2011-10-01

Hyaluronic acid (HA) has several clinical applications (aesthetic surgery, dermatology, orthopaedics and ophtalmology). Following recent evidence, suggesting antimicrobial and antiviral properties for HA, we investigated its effects on 15 ATCC strains, representative of clinically relevant bacterial and fungal species. The in vitro system employed allowed to assess optical density of broth cultures as a measure of microbial load in a time-dependent manner. The results showed that different microbial species and, sometimes, different strains belonging to the same species, are differently affected by HA. In particular, staphylococci, enterococci, Streptococcus mutans, two Escherichia coli strains, Pseudomonas aeruginosa, Candida glabrata and C. parapsilosis displayed a HA dose-dependent growth inhibition; no HA effects were detected in E. coli ATCC 13768 and C. albicans; S. sanguinis was favoured by the highest HA dose. Therefore, the influence of HA on bacteria and fungi warrants further studies aimed at better establishing its relevance in clinical applications.

Aquatic ecotoxicity of ashes from Brazilian savanna wildfires.

PubMed

Brito, Darlan Q; Passos, Carlos José S; Muniz, Daphne H F; Oliveira-Filho, Eduardo C

2017-08-01

In a global scenario of climate change, several studies have predicted an increase in fires in different parts of the world. With the occurrence of rains following the fires in the Brazilian savanna (Cerrado biome), the compounds present in ashes may enter aquatic environments and cause adverse effects to these ecosystems. In this context, this study evaluated the potential toxicity of ashes from two areas of Cerrado and an area of pasture, through ecotoxicological bioassays and using three aquatic species from distinct trophic levels, which were exposed to different dilutions of ashes: the microcrustacean Ceriodaphnia dubia, the fish Danio rerio and the mollusc Biomphalaria glabrata. The ashes from the three sampled areas showed higher concentrations of some elements in relation to the soil samples (B, Ca, K, Mg, Mn, P, S, Si, Sr, Zn), but only a small quantity of these compounds was solubilised. Our data showed that all ash samples caused acute toxicity to C. dubia (48hs-LC 50  = 13.4 g L -1 ; 48hs-LC 50  = 6.33 g L -1 ; 48hs-LC 50  = 9.73 g L -1 respectively for transition area, pasture, typical cerrado areas), while in relation to D. rerio and B. glabrata, no acute toxicity was observed when they were exposed to ashes from native Cerrado vegetation and pasture areas. Ashes from a transition area showed toxicity for D. rerio (48hs-LC 50  = 25.0 g L -1 ); possibly, this was due to the combination of multiple preponderant inorganic elements of ashes with other organic compounds not analysed, such as polycyclic aromatic hydrocarbons (PAHs). In summary, these results suggest that wildfires may pose risks to zooplankton communities and emphasize the need for more studies to better understand the complexity of the ecological effects of fire on aquatic ecosystems.

Oxidative and interactive challenge of cadmium and ocean acidification on the smooth scallop Flexopecten glaber.

PubMed

Nardi, Alessandro; Benedetti, Maura; Fattorini, Daniele; Regoli, Francesco

2018-03-01

Ocean acidification (OA) may affect sensitivity of marine organisms to metal pollution modulating chemical bioavailability, bioaccumulation and biological responsiveness of several cellular pathways. In this study, the smooth scallop Flexopecten glaber was exposed to various combinations of reduced pH (pH/pCO 2 7.4/∼3000 μatm) and Cd (20 μg/L). The analyses on cadmium uptake were integrated with those of a wide battery of biomarkers including metallothioneins, single antioxidant defenses and total oxyradical scavenging capacity in digestive gland and gills, lysosomal membrane stability and onset of genotoxic damage in haemocytes. Reduced pH slightly increased concentration of Cd in scallop tissues, but no effects were measured in terms of metallothioneins. Induction of some antioxidants by Cd and/or low pH in the digestive gland was not reflected in variations of the total oxyradical scavenging capacity, while the investigated stressors caused a certain inhibition of antioxidants and reduction of the scavenging capacity toward peroxyl radical in the gills. Lysosomal membrane stability and onset of genotoxic damages showed high sensitivity with possible synergistic effects of the investigated factors. The overall results suggest that indirect effects of ocean acidification on metal accumulation and toxicity are tissue-specific and modulate oxidative balance through different mechanisms. Copyright © 2018 Elsevier B.V. All rights reserved.

[Comparison between conventional methods, ChromAgar Candida® and PCR method for the identification of Candida species in clinical isolates].

PubMed

Estrada-Barraza, Deyanira; Dávalos Martínez, Arturo; Flores-Padilla, Luis; Mendoza-De Elias, Roberto; Sánchez-Vargas, Luis Octavio

2011-01-01

The increase in the incidence of yeast species causing fungemia in susceptible immunocompromised patients in the last two decades and the low sensitivity of conventional blood culture has led to the need to develop alternative approaches for the early detection and identification of causative species. The aim of this study was to compare the usefulness of molecular testing by the polymerase chain reaction (PCR) and conventional methods to identify clinical isolates of different species, using the ID32C ATB system (bioMérieux, France), chromogenic culture Chromagar Candida® (CHROMagar, France) and morphogenesis in corn meal agar. We studied 79 isolates, in which the most prevalent species using the system ID32C and PCR was C. albicans, followed by C. tropicalis, C. glabrata and C .krusei. PCR patterns obtained for the identification of clinical isolates were stable and consistent in the various independent studies and showed good reproducibility, concluding that PCR with species-specific primers that amplify genes ITS1 and ITS2 for rRNA or topoisomerase II primers is a very specific and sensitive method for the identification of C. glabrata, C. krusei, C. albicans, and with less specificity for C. tropicalis. Copyright © 2010 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Analysis of Polyphenolic Compounds in Extracts from Leaves of Some Malus domestica Cultivars: Antiradical and Antimicrobial Analysis of These Extracts

PubMed Central

Sowa, Alina; Zgórka, Grażyna; Szykuła, Aleksandra; Franiczek, Roman; Żbikowska, Beata; Gamian, Andrzej

2016-01-01

In this study, methanol, ethyl acetate, water extracts, and precipitate were obtained from leaves of Malus domestica cultivars: Golden delicious, Jonagold, Elstar, Ligol, and Mutsu. Antiradical activity of these extracts was measured using the ABTS+∙ radical, and antimicrobial activity was measured with the disk-diffusion method. Phenolic compounds were measured with the colorimetric method and identified with high performance liquid chromatography (HPLC). The highest antiradical activity was observed for the Jonagold variety, and in particular strong activity was noted for ethyl acetate extracts. Antimicrobial activity was observed against strains of Staphylococcus aureus, Enterococcus faecalis, and the fungus Candida glabrata. Particularly susceptible to the extracts activity appeared to be Staphylococcus aureus, but the growth of Candida glabrata was inhibited in the presence of ethyl acetate extracts. With the HPLC method we identified a high amount of phloridzin (above 500 mg per g of ethyl acetate extracts), lower amounts of hyperoside, isoquercitrin, and quercitrin, and traces of p-hydroxybenzoic and chlorogenic acids. The contribution of phloridzin to antiradical activity of methanol and ethyl acetate extracts was very high (above 90%). In water extract the contribution of phloridzin was between 38.9 and 55.2%, chlorogenic acid 22.7 and 36.1%, and hyperoside 12.2 and 13.3%. PMID:28097143

Analysis of Polyphenolic Compounds in Extracts from Leaves of Some Malus domestica Cultivars: Antiradical and Antimicrobial Analysis of These Extracts.

PubMed

Sowa, Alina; Zgórka, Grażyna; Szykuła, Aleksandra; Franiczek, Roman; Żbikowska, Beata; Gamian, Andrzej; Sroka, Zbigniew

2016-01-01

In this study, methanol, ethyl acetate, water extracts, and precipitate were obtained from leaves of Malus domestica cultivars: Golden delicious, Jonagold, Elstar, Ligol, and Mutsu. Antiradical activity of these extracts was measured using the ABTS +∙ radical, and antimicrobial activity was measured with the disk-diffusion method. Phenolic compounds were measured with the colorimetric method and identified with high performance liquid chromatography (HPLC). The highest antiradical activity was observed for the Jonagold variety, and in particular strong activity was noted for ethyl acetate extracts. Antimicrobial activity was observed against strains of Staphylococcus aureus , Enterococcus faecalis , and the fungus Candida glabrata . Particularly susceptible to the extracts activity appeared to be Staphylococcus aureus , but the growth of Candida glabrata was inhibited in the presence of ethyl acetate extracts. With the HPLC method we identified a high amount of phloridzin (above 500 mg per g of ethyl acetate extracts), lower amounts of hyperoside, isoquercitrin, and quercitrin, and traces of p -hydroxybenzoic and chlorogenic acids. The contribution of phloridzin to antiradical activity of methanol and ethyl acetate extracts was very high (above 90%). In water extract the contribution of phloridzin was between 38.9 and 55.2%, chlorogenic acid 22.7 and 36.1%, and hyperoside 12.2 and 13.3%.

Mitochondrial Cochaperone Mge1 Is Involved in Regulating Susceptibility to Fluconazole in Saccharomyces cerevisiae and Candida Species.

PubMed

Demuyser, Liesbeth; Swinnen, Erwin; Fiori, Alessandro; Herrera-Malaver, Beatriz; Vestrepen, Kevin; Van Dijck, Patrick

2017-07-18

MGE1 encodes a yeast chaperone involved in Fe-S cluster metabolism and protein import into the mitochondria. In this study, we identified MGE1 as a multicopy suppressor of susceptibility to the antifungal fluconazole in the model yeast Saccharomyces cerevisiae We demonstrate that this phenomenon is not exclusively dependent on the integrity of the mitochondrial DNA or on the presence of the drug efflux pump Pdr5. Instead, we show that the increased dosage of Mge1 plays a protective role by retaining increased amounts of ergosterol upon fluconazole treatment. Iron metabolism and, more particularly, Fe-S cluster formation are involved in regulating this process, since the responsible Hsp70 chaperone, Ssq1, is required. Additionally, we show the necessity but, by itself, insufficiency of activating the iron regulon in establishing the Mge1-related effect on drug susceptibility. Finally, we confirm a similar role for Mge1 in fluconazole susceptibility in the pathogenic fungi Candida glabrata and Candida albicans IMPORTANCE Although they are mostly neglected compared to bacterial infections, fungal infections pose a serious threat to the human population. While some of them remain relatively harmless, infections that reach the bloodstream often become lethal. Only a few therapies are available, and resistance of the pathogen to these drugs is a frequently encountered problem. It is thus essential that more research is performed on how these pathogens cope with the treatment and cause recurrent infections. Baker's yeast is often used as a model to study pathogenic fungi. We show here, by using this model, that iron metabolism and the formation of the important iron-sulfur clusters are involved in regulating susceptibility to fluconazole, the most commonly used antifungal drug. We show that the same process likely also occurs in two of the most regularly isolated pathogenic fungi, Candida glabrata and Candida albicans . Copyright © 2017 Demuyser et al.

VT-1161 protects mice against oropharyngeal candidiasis caused by fluconazole-susceptible and -resistant Candida albicans

PubMed Central

Break, Timothy J; Desai, Jigar V; Ferre, Elise M N; Henderson, Christina; Zelazny, Adrian M; Siebenlist, Ulrich; Hoekstra, William J; Schotzinger, Robert J; Garvey, Edward P; Lionakis, Michail S

2018-01-01

Abstract Background Candida albicans, the most common human fungal pathogen, causes chronic mucosal infections in patients with inborn errors of IL-17 immunity that rely heavily on chronic, often lifelong, azole antifungal agents for treatment. However, a rise in azole resistance has predicated a need for developing new antifungal drugs. Objectives To test the in vitro and in vivo efficacy of VT-1161 and VT-1129 in the treatment of oropharyngeal candidiasis with azole-susceptible or -resistant C. albicans strains. Methods MICs of VT-1161, VT-1129 and nine licensed antifungal drugs were determined for 31 Candida clinical isolates. The drug concentrations in mouse serum and tongues were measured following oral administration. IL-17-signalling-deficient Act1−/− mice were infected with fluconazole-susceptible or fluconazole-resistant C. albicans strains, and the amount of mucosal fungal burden was determined after fluconazole or VT-1161 treatment. Results Fourteen isolates (45%) were not fluconazole susceptible (MIC ≥4 mg/L). VT-1161 and VT-1129 showed significant in vitro activity against the majority of the 31 mucosal clinical isolates (MIC50 0.03 and 0.06 mg/L, respectively), including Candida glabrata (MIC50, 0.125 and 0.25 mg/L, respectively). After oral doses, VT-1161 and VT-1129 concentrations in mouse serum and tongues were well above their MIC50 values. VT-1161 was highly effective as treatment of both fluconazole-susceptible and -resistant oropharyngeal candidiasis in Act1−/− mice. Conclusions VT-1129 and VT-1161 exhibit significant in vitro activity against Candida strains, including fluconazole-resistant C. albicans and C. glabrata. VT-1161 administration in mice results in significant mucosal drug accumulation and eradicates infection caused by fluconazole-susceptible and -resistant Candida strains. PMID:29040636

In Vitro Anti-Candida Activity of Lidocaine and Nitroglycerin: Alone and Combined

PubMed Central

Palmeira-de-Oliveira, Ana; Ramos, Ana Rita; Gaspar, Carlos; Palmeira-de-Oliveira, Rita; Gouveia, Paula; Martinez-de-Oliveira, José

2012-01-01

The aim of this work was to study the anti-Candida activity of lidocaine and nitroglycerin alone and in combination. Ten Candida strains were included, corresponding to 1 collection type strain (ATCC 10231) and 9 clinical isolates: 4 C. albicans, 2 C. glabrata, 1 C. tropicalis, 1 C. krusei, and 1 C. parapsilosis. The CLSI reference M27-A3 micromethod was used to determine the anti-Candida activity of the drugs alone; minimal inhibitory and lethal concentrations were determined. The classic checkboard technique was used to determine the activity of combined drugs. Lidocaine fungicidal effect was dosedependent. Nitroglycerin exhibited a higher effect. The drugs combination resulted in a reduction of the inhibitory concentration, corresponding to an additive effect. In conclusion, both drugs exhibited an interesting anti-Candida activity. The combination of lidocaine with nitroglycerin was shown to have an additive effect against Candida spp., predicting the interest to include, in the future, these drugs in a new delivery system for the treatment of mucocutaneous candidosis. PMID:22675243

Dietary supplement of banana (Musa acuminata) peels hot-water extract to enhance the growth, anti-hypothermal stress, immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii.

PubMed

Rattanavichai, Wutti; Cheng, Winton

2015-04-01

In the present study, Macrobrachium rosenbergii were fed with diets containing extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). The non-specific immune parameters, disease resistance and anti-hypothermal stress were evaluated at 2, 4, 8, 16 and 32 days of post feeding. Also, we demonstrated the percent weight gain (PWG), percent length gain (PLG), feeding efficiency (FE), and survival rate of giant freshwater prawn at 30, 60, 90, and 120 days of post feeding. The PWG, PLG, FE and survival rate of prawns fed at 0, 1.0, 3.0 and 6.0 g kg(-1) BPE-containing diets after 120 days were 69.5%, 75.4%, 77.8% and 83.3%; 21.8%, 23.6%, 27.8% and 33.9%; 0.60, 0.72, 0.75 and 0.90; and 55.4%, 62.2%, 62.3% and 75.3%, respectively. After 32 days of post feeding, a significant increase in total haemocyte count (THC), different haemocyte count (DHC), respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, phenoloxidase (PO) activity and transglutaminase (TG) activity, and meanwhile, a decreased haemolymph coagulation time was observed. Furthermore, phagocytic activity and clearance efficiency of prawns against Lactococcus garvieae infection were significantly increased. Prawns challenged with L. garvieae after 32 days of feeding at 1.0, 3.0 and 6.0 g kg(-1) had a significantly higher survival rate (33.3%, 40.0% and 56.7%) than those fed with the control diet. Subsequently, hypothermal (14 °C) stress was 43.4%, 50.0% and 50.0%, respectively. Altogether, we therefore recommend the dietary BPE administration at 6.0 g kg(-1) promotes growth, anti-hypothermal stress, and enhance immunity and resistance against L. garvieae in M. rosenbergii. Copyright © 2015 Elsevier Ltd. All rights reserved.

Two novel LRR-only proteins in Chlamys farreri: Similar in structure, yet different in expression profile and pattern recognition.

PubMed

Wang, Mengqiang; Wang, Lingling; Xin, Lusheng; Wang, Xiudan; Wang, Lin; Xu, Jianchao; Jia, Zhihao; Yue, Feng; Wang, Hao; Song, Linsheng

2016-06-01

Leucine-rich repeat (LRR)-only proteins could mediate protein-ligand and protein-protein interactions and be involved in the immune response. In the present study, two novel LRR-only proteins, CfLRRop-2 and CfLRRop-3, were identified and characterized from scallop Chlamys farreri. They both contained nine LRR motifs with the consensus signature sequence LxxLxLxxNxL and formed typical horseshoe structure. The CfLRRop-2 and CfLRRop-3 mRNA transcripts were constitutively expressed in haemocytes, muscle, mantle, gill, haepatopancreas and gonad, with the highest expression level in haepatopancreas and gill, respectively. During the ontogenesis of scallop, the mRNA transcripts of CfLRRop-2 were kept at a high level in oocytes and embryos, while those of CfLRRop-3 were expressed at a rather low level from oocytes to blastula. Their mRNA transcripts were significantly increased after the stimulation of lipopolysaccharide (LPS), peptidoglycan (PGN), glucan (GLU) and polyinosinic-polycytidylic acid (poly I:C), and the mRNA expression of CfLRRop-2 rose more intensely than that of CfLRRop-3. After the suppression of CfTLR (previously identified Toll-like receptor in C. farreri) via RNA interference (RNAi), CfLRRop-3 mRNA transcripts increased more intensely and lastingly than those of CfLRRop-2. The rCfLRRop-3 protein could bind LPS, PGN, GLU and poly I:C, while rCfLRRop-2 exhibited no significant binding activity to them. Additionally, rCfLRRop-2 could significantly induce the release of TNF-α from the mixed primary cultured scallop haemocytes, but rCfLRRop-3 failed. These results collectively indicated that CfLRRop-2 might act as an immune effector or pro-inflammatory factor, while CfLRRop-3 would function as a pattern recognition receptor (PRR), suggesting the function of LRR-only protein family has differentiated in scallop. Copyright © 2016 Elsevier Ltd. All rights reserved.

Probiotic Lactobacillus reuteri has antifungal effects on oral Candida species in vitro

PubMed Central

Jørgensen, Mette Rose; Kragelund, Camilla; Jensen, Peter Østrup; Keller, Mette Kirstine; Twetman, Svante

2017-01-01

ABSTRACT Background: An alternative approach for managing Candida infections in the oral cavity by modulating the oral microbiota with probiotic bacteria has been proposed. Objective: The aim was to investigate the antifungal potential of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) against six oral Candida species (C. albicans, C. glabrata, C. krusei, C. tropicalis, C. dubliniensis, and C. parapsilosis). Design: The lactobacilli were tested for their ability to co-aggregate with and inhibit the growth of the yeasts assessed by spectrophotometry and the agar overlay inhibition assay. Additionally, the pH was evaluated with microsensors, and the production of hydrogen peroxide (H2O2) by the lactobacilli was verified. Results: Both L. reuteri strains showed co-aggregation abilities with the yeasts. The lactobacilli almost completely inhibited the growth of C. albicans and C. parapsilosis, but did not affect C. krusei. Statistically significant differences in co-aggregation and growth inhibition capacities between the two L. reuteri strains were observed (p<0.001). The pH measurements suggested that C. krusei can resist the acids produced by the lactobacilli. Conclusions: L. reuteri exhibited antifungal properties against five of the six most common oral Candida species. Further, the results reconfirms that the probiotic capacity of L. reuteri is strain specific. PMID:28326154

Predictive Virtual Infection Modeling of Fungal Immune Evasion in Human Whole Blood.

PubMed

Prauße, Maria T E; Lehnert, Teresa; Timme, Sandra; Hünniger, Kerstin; Leonhardt, Ines; Kurzai, Oliver; Figge, Marc Thilo

2018-01-01

Bloodstream infections by the human-pathogenic fungi Candida albicans and Candida glabrata increasingly occur in hospitalized patients and are associated with high mortality rates. The early immune response against these fungi in human blood comprises a concerted action of humoral and cellular components of the innate immune system. Upon entering the blood, the majority of fungal cells will be eliminated by innate immune cells, i.e., neutrophils and monocytes. However, recent studies identified a population of fungal cells that can evade the immune response and thereby may disseminate and cause organ dissemination, which is frequently observed during candidemia. In this study, we investigate the so far unresolved mechanism of fungal immune evasion in human whole blood by testing hypotheses with the help of mathematical modeling. We use a previously established state-based virtual infection model for whole-blood infection with C. albicans to quantify the immune response and identified the fungal immune-evasion mechanism. While this process was assumed to be spontaneous in the previous model, we now hypothesize that the immune-evasion process is mediated by host factors and incorporate such a mechanism in the model. In particular, we propose, based on previous studies that the fungal immune-evasion mechanism could possibly arise through modification of the fungal surface by as of yet unknown proteins that are assumed to be secreted by activated neutrophils. To validate or reject any of the immune-evasion mechanisms, we compared the simulation of both immune-evasion models for different infection scenarios, i.e., infection of whole blood with either C. albicans or C. glabrata under non-neutropenic and neutropenic conditions. We found that under non-neutropenic conditions, both immune-evasion models fit the experimental data from whole-blood infection with C. albicans and C. glabrata . However, differences between the immune-evasion models could be observed for the

Predictive Virtual Infection Modeling of Fungal Immune Evasion in Human Whole Blood

PubMed Central

Prauße, Maria T. E.; Lehnert, Teresa; Timme, Sandra; Hünniger, Kerstin; Leonhardt, Ines; Kurzai, Oliver; Figge, Marc Thilo

2018-01-01

Bloodstream infections by the human-pathogenic fungi Candida albicans and Candida glabrata increasingly occur in hospitalized patients and are associated with high mortality rates. The early immune response against these fungi in human blood comprises a concerted action of humoral and cellular components of the innate immune system. Upon entering the blood, the majority of fungal cells will be eliminated by innate immune cells, i.e., neutrophils and monocytes. However, recent studies identified a population of fungal cells that can evade the immune response and thereby may disseminate and cause organ dissemination, which is frequently observed during candidemia. In this study, we investigate the so far unresolved mechanism of fungal immune evasion in human whole blood by testing hypotheses with the help of mathematical modeling. We use a previously established state-based virtual infection model for whole-blood infection with C. albicans to quantify the immune response and identified the fungal immune-evasion mechanism. While this process was assumed to be spontaneous in the previous model, we now hypothesize that the immune-evasion process is mediated by host factors and incorporate such a mechanism in the model. In particular, we propose, based on previous studies that the fungal immune-evasion mechanism could possibly arise through modification of the fungal surface by as of yet unknown proteins that are assumed to be secreted by activated neutrophils. To validate or reject any of the immune-evasion mechanisms, we compared the simulation of both immune-evasion models for different infection scenarios, i.e., infection of whole blood with either C. albicans or C. glabrata under non-neutropenic and neutropenic conditions. We found that under non-neutropenic conditions, both immune-evasion models fit the experimental data from whole-blood infection with C. albicans and C. glabrata. However, differences between the immune-evasion models could be observed for the

Effect of molecular weight and concentration of legume condensed tannins on in vitro larval migration inhibition of Haemonchus contortus.

PubMed

Naumann, H D; Armstrong, S A; Lambert, B D; Muir, J P; Tedeschi, L O; Kothmann, M M

2014-01-17

The effect of molecular weight of condensed tannins (CT) from a variety of warm-season perennial legumes commonly consumed by sheep and goats on anthelmintic activity has not been previously explored. The objectives of this study were to determine if molecular weight of CT from warm-season perennial legumes could predict the biological activity of CT relative to anthelmintic activity against ivermectin resistant L3 stage Haemonchus contortus (HC) using a larval migration inhibition (LMI) assay. A second objective was to determine if CT from warm-season perennial legumes possess anthelmintic properties against L3 stage (HC). Lespedeza stuevei had the greatest concentration of total condensed tannin (TCT; 11.7%), whereas, with the exception of Arachis glabrata, a CT-free negative control, Leucaena retusa had the least TCT (3.3%). Weight-average molecular weight of CT ranged from 552 Da for L. stuevei to 1483 Da for Lespedeza cuneata. The treatments demonstrating the greatest percent LMI were L. retusa, L. stuevei and Acacia angustissima var. hirta (65.4%, 63.1% and 42.2%, respectively). The ivermectin treatment had the smallest percent LMI (12.5%) against ivermectin resistant L3 HC. There was a weak correlation (R(2)=0.34; P=0.05) between CT MW and percent LMI, suggesting that molecular weight of CT is a weak contributing factor to CT biological activity as it relates to LMI of L3 stage HC. L. stuevei, L. retusa and A. angustissima var. hirta STP5 warrant further evaluation of anthelmintic properties in vivo. Copyright © 2013 Elsevier B.V. All rights reserved.

Oral Administration of the Broad-Spectrum Antibiofilm Compound Toremifene Inhibits Candida albicans and Staphylococcus aureus Biofilm Formation In Vivo

PubMed Central

De Cremer, Kaat; Delattin, Nicolas; De Brucker, Katrijn; Peeters, Annelies; Kucharíková, Soña; Gerits, Evelien; Verstraeten, Natalie; Michiels, Jan; Van Dijck, Patrick; Thevissen, Karin

2014-01-01

We here report on the in vitro activity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, including Candida albicans, Candida glabrata, Candida dubliniensis, Candida krusei, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We validated the in vivo efficacy of orally administered toremifene against C. albicans and S. aureus biofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound. PMID:25288093

A water snail catches a ride on STS-90 as part of Neurolab

NASA Technical Reports Server (NTRS)

1998-01-01

A water snail (Biomphalaria glabrata), like those that are part of the Neurolab payload on Space Shuttle Mission STS-90, is held up for inspection in the Operations and Checkout Building. The snails will fly in the Closed Equilibrated Biological Aquatic System (CEBAS) Minimodule, a middeck locker-sized fresh water habitat, designed to allow the controlled incubation of aquatic species in a self-stabilizing, artifical ecosystem for up to three weeks under space conditions. Investigations during the Neurolab mission will focus on the effects of microgravity on the nervous system. The crew of STS-90, slated for launch April 16 at 2:19 p.m. EDT, includes Commander Richard Searfoss, Pilot Scott Altman, Mission Specialists Richard Linnehan, D.V.M., Dafydd (Dave) Williams, M.D., and Kathryn (Kay) Hire, and Payload Specialists Jay Buckey, M.D., and James Pawelczyk, Ph.D.

[The role of the symptomatic and asymptomatic sexual partners in the recurrent vulvovaginitis].

PubMed

Boatto, Humberto Fabio; Girão, Manoel João Batista Castello; de Moraes, Maria Sayonara; Francisco, Elaine Cristina; Gompertz, Olga Fischman

2015-07-01

To identify the predominant species and the role of sexual partners in the maintenance of recurrent vulvovaginitis by Candida spp. A prospective study of 830 patients aged 18 to 65 years with yeast vaginitis was performed between August 2007 and March 2012. Patients with diabetes mellitus, AIDS or taking corticosteroids, antibiotics or hormone therapy and immunosuppressed patients, patients using vaginal douches, spermicides or intrauterine devices were excluded from the study. Candida species were identified by phenotypic and genotypic methods. The chi-square test was used to correlate the presence of Candida spp. in male partners with the recurrence of vaginitis. The fungal agent was isolated from a total of 40 women, 24 with recurrent vaginitis and from 15 of their sexual partners, 10 of whom were asymptomatic while 5 were symptomatic. There was agreement of the species found in the couple in 100% of recurrences. C. albicans (62.4 and 60%), C. glabrata (29.1 and 33.3%) and C. guilliermondii species were identified. Candida tropicalis (4.1%) was isolated from only one patient. Candida albicans was isolated from the remaining 16 women who had uncomplicated vaginitis. C. glabrata was isolated from only two of the asymptomatic partners. There was a predominance of C. albicans and symptomatic or asymptomatic partners can play an important role as a reservoir and source of transmission of yeast, especially in cases of recurrent vulvovaginitis.

Phenotypic Detection of Genitourinary Candidiasis among Sexually Transmitted Disease Clinic Attendees in Ladoke Akintola University Teaching Hospital, Osogbo, Nigeria

PubMed Central

Obisesan, Oluranti J.; Olowe, Olugbenga A.; Taiwo, Samuel S.

2015-01-01

The management of genitourinary candidiasis (GC) is fraught with challenges, especially, in an era of increasing antifungal resistance. This descriptive cross-sectional study conducted between May 2013 and January 2014 determined the prevalence and characteristics of GC and the species of Candida among 369 attendees of a Sexually Transmitted Disease (STD) clinic of Ladoke Akintola University Teaching Hospital, Osogbo, Nigeria. Appropriate urogenital specimen collected from each attendee was examined by microscopy and culture for Candida, with preliminary species identification by CHROMAgar Candida and confirmation by Analytical Profile Index (API) 20C AUX. The age range of attendees was 1-80 years, mean age was 36.32 ± 11.34 years, and male to female ratio was 1 to 3. The prevalence of genitourinary candidiasis was 47.4%, with 4.9% in males and 42.5% in females (p < 0.0001). The age groups 31–45 and 16–30 have the highest prevalence of 23.3% and 16.8%, respectively. The species of Candida recovered include Candida glabrata 46.9%, Candida albicans 33.7%, Candida dubliniensis 9.7%, Candida tropicalis 5.7%, Candida krusei 1.7%, Candida lusitaniae 1.7%, and Candida utilis 0.6%. This study reported non-C. albicans Candida, especially C. glabrata, as the most frequently isolated species in GC, contrary to previous studies in this environment and elsewhere. PMID:26064140

[Aetiology of candidiasis in paediatric patients: Comparative analysis with adult patients].

PubMed

Gil-Tomás, Jesús J; Colomina-Rodríguez, Javier

2016-01-01

Candida spp. represents a group of commensal yeasts that can act as pathogens and cause candidiasis in different anatomical locations. The aim of this study was to perform an epidemiological and comparative analysis between the isolates of Candida spp. in clinical specimens during a three year-period (2010-2012) from children (0-14 years) and adults (15-99 years) in the Valencian Community (RedMIVA). The microbiological surveillance network of Valencian Community was used as the information source. Candida was isolated in 52,436 patients (1,604 [3.1%] children and 50,832 [96.9%] adults). Candida albicans was significantly (p<0.05) the predominant species in both age groups, and in almost every type of clinical specimen. The distribution of other species varied depending on the sample type and age group. In blood specimens, Candida parapsilosis followed by C. albicans, Candida famata and Candida lusitaniae were the main species found in children, whereas C. albicans followed by C. parapsilosis, Candida glabrata and Candida tropicalis were the predominant species in adults. In sterile fluids, urine and lower respiratory tract samples, C. parapsilosis was the second most prevalent species in the children group, while C. glabrata and C. tropicalis were the main second species in adults. Copyright © 2015 Asociación Española de Micología. Published by Elsevier Espana. All rights reserved.

Identification of proteins involved in the adhesionof Candida species to different medical devices.

PubMed

Núñez-Beltrán, Arianna; López-Romero, Everardo; Cuéllar-Cruz, Mayra

2017-06-01

Adhesion is the first step for Candida species to form biofilms on medical devices implanted in the human host. Both the physicochemical nature of the biomaterial and cell wall proteins (CWP) of the pathogen play a determinant role in the process. While it is true that some CWP have been identified in vitro, little is known about the CWP of pathogenic species of Candida involved in adhesion. On this background, we considered it important to investigate the potential role of CWP of C. albicans, C. glabrata, C. krusei and C. parapsilosis in adhesion to different medical devices. Our results indicate that the four species strongly adher to polyvinyl chloride (PVC) devices, followed by polyurethane and finally by silicone. It was interesting to identify fructose-bisphosphate aldolase (Fba1) and enolase 1 (Eno1) as the CWP involved in adhesion of C. albicans, C. glabrata and C. krusei to PVC devices whereas phosphoglycerate kinase (Pgk) and Eno1 allow C. parapsilosis to adher to silicone-made implants. Results presented here suggest that these CWP participate in the initial event of adhesion and are probably followed by other proteins that covalently bind to the biomaterial thus providing conditions for biofilm formation and eventually the onset of infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multidrug-Resistant Candida: Epidemiology, Molecular Mechanisms, and Treatment.

PubMed

Arendrup, Maiken Cavling; Patterson, Thomas F

2017-08-15

Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients. Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites of infection/colonization, drug sequestration in the biofilm matrix, and, in the setting of outbreaks, suboptimal infection control. Moreover, recent research suggests that DNA mismatch repair gene mutations may facilitate acquisition of resistance mutations in C. glabrata specifically. Diagnosis of antifungal-resistant Candida infections is critical to the successful management of patients with these infections. Reduction of unnecessary use of antifungals via antifungal stewardship is critical to limit multidrug resistance emergence. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Synthesis, Molecular Docking, and Antimycotic Evaluation of Some 3-Acyl Imidazo[1,2-a]pyrimidines.

PubMed

Gómez-García, Omar; Andrade-Pavón, Dulce; Campos-Aldrete, Elena; Ballinas-Indilí, Ricardo; Méndez-Tenorio, Alfonso; Villa-Tanaca, Lourdes; Álvarez-Toledano, Cecilio

2018-03-07

A series of 3-benzoyl imidazo[1,2- a ]pyrimidines, obtained from N -heteroarylformamidines in good yields, was tested in silico and in vitro for binding and inhibition of seven Candida species ( Candida albicans (ATCC 10231), Candida dubliniensis (CD36), Candida glabrata (CBS138), Candida guilliermondii (ATCC 6260), Candida kefyr , Candida krusei (ATCC 6358) and Candida tropicalis (MYA-3404)). To predict binding mode and energy, each compound was docked in the active site of the lanosterol 14α-demethylase enzyme (CYP51), essential for fungal growth of Candida species. Antimycotic activity was evaluated as the 50% minimum inhibitory concentration (MIC50) for the test compounds and two reference drugs, ketoconazole and fluconazole. All test compounds had a better binding energy (range: -6.11 to -9.43 kcal/mol) than that found for the reference drugs (range: 48.93 to -6.16 kcal/mol). In general, the test compounds showed greater inhibitory activity of yeast growth than the reference drugs. Compounds 4j and 4f were the most active, indicating an important role in biological activity for the benzene ring with electron-withdrawing substituents. These compounds show the best MIC50 against C. guilliermondii and C. glabrata, respectively. The current findings suggest that the 3-benzoyl imidazo[1,2- a ]pyrimidine derivatives, herein synthesized by an accessible methodology, are potential antifungal drugs.

Phenotypic Detection of Genitourinary Candidiasis among Sexually Transmitted Disease Clinic Attendees in Ladoke Akintola University Teaching Hospital, Osogbo, Nigeria.

PubMed

Obisesan, Oluranti J; Olowe, Olugbenga A; Taiwo, Samuel S

2015-01-01

The management of genitourinary candidiasis (GC) is fraught with challenges, especially, in an era of increasing antifungal resistance. This descriptive cross-sectional study conducted between May 2013 and January 2014 determined the prevalence and characteristics of GC and the species of Candida among 369 attendees of a Sexually Transmitted Disease (STD) clinic of Ladoke Akintola University Teaching Hospital, Osogbo, Nigeria. Appropriate urogenital specimen collected from each attendee was examined by microscopy and culture for Candida, with preliminary species identification by CHROMAgar Candida and confirmation by Analytical Profile Index (API) 20C AUX. The age range of attendees was 1-80 years, mean age was 36.32 ± 11.34 years, and male to female ratio was 1 to 3. The prevalence of genitourinary candidiasis was 47.4%, with 4.9% in males and 42.5% in females (p < 0.0001). The age groups 31-45 and 16-30 have the highest prevalence of 23.3% and 16.8%, respectively. The species of Candida recovered include Candida glabrata 46.9%, Candida albicans 33.7%, Candida dubliniensis 9.7%, Candida tropicalis 5.7%, Candida krusei 1.7%, Candida lusitaniae 1.7%, and Candida utilis 0.6%. This study reported non-C. albicans Candida, especially C. glabrata, as the most frequently isolated species in GC, contrary to previous studies in this environment and elsewhere.

Evaluation of the Microbial Identification System for identification of clinically isolated yeasts.

PubMed Central

Crist, A E; Johnson, L M; Burke, P J

1996-01-01

The Microbial Identification System (MIS; Microbial ID, Inc., Newark, Del.) was evaluated for the identification of 550 clinically isolated yeasts. The organisms evaluated were fresh clinical isolates identified by methods routinely used in our laboratory (API 20C and conventional methods) and included Candida albicans (n = 294), C. glabrata (n = 145), C. tropicalis (n = 58), C. parapsilosis (n = 33), and other yeasts (n = 20). In preparation for fatty acid analysis, yeasts were inoculated onto Sabouraud dextrose agar and incubated at 28 degrees C for 24 h. Yeasts were harvested, saponified, derivatized, and extracted, and fatty acid analysis was performed according to the manufacturer's instructions. Fatty acid profiles were analyzed, and computer identifications were made with the Yeast Clinical Library (database version 3.8). Of the 550 isolates tested, 374 (68.0%) were correctly identified to the species level, with 87 (15.8%) being incorrectly identified and 89 (16.2%) giving no identification. Repeat testing of isolates giving no identification resulted in an additional 18 isolates being correctly identified. This gave the MIS an overall identification rate of 71.3%. The most frequently misidentified yeast was C. glabrata, which was identified as Saccharomyces cerevisiae 32.4% of the time. On the basis of these results, the MIS, with its current database, does not appear suitable for the routine identification of clinically important yeasts. PMID:8880489

Critical analysis of molluscicide application in schistosomiasis control programs in Brazil.

PubMed

Coelho, Pmz; Caldeira, R L

2016-07-04

In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are naturally infected by the trematode Schistosoma mansoni, the causative agent of schistosomiasis. Despite decades of governmental efforts through official control programs, schistosomiasis remains an important public health problem in the country: thousands of people are infected with the trematode each year and millions live in endemic areas. The World Health Organization recommends using a combination of molluscicide (niclosamide) and mass chemotherapy to control the transmission of schistosomiasis, with this treatment successfully reducing the morbidity of the disease. In the past, niclosamide has been used in official schistosomiasis control programs in Brazil. However, as B. glabrata recolonizes even after molluscicide application, the use of molluscicides has gradually decreased in the country until they were discontinued in 2002, mainly due to the rising global pressure to preserve the environment and the difficulties of obtaining licenses from the Brazilian Ministry of Environment to use toxic substances in aquatic ecosystems. Therefore, the discovery of new molluscicides, which could be more selective to Biomphalaria species and less harmful to the aquatic ecosystem, is necessary. In addition, political efforts to sensitize funders to provide grants for this field of research are required. In this context, this article aims to make a critical analysis of molluscicide application in schistosomiasis control programs in Brazil.

Roles of Calcineurin and Crz1 in Antifungal Susceptibility and Virulence of Candida glabrata▿

PubMed Central

Miyazaki, Taiga; Yamauchi, Shunsuke; Inamine, Tatsuo; Nagayoshi, Yosuke; Saijo, Tomomi; Izumikawa, Koichi; Seki, Masafumi; Kakeya, Hiroshi; Yamamoto, Yoshihiro; Yanagihara, Katsunori; Miyazaki, Yoshitsugu; Kohno, Shigeru

2010-01-01

A Candida glabrata calcineurin mutant exhibited increased susceptibility to both azole antifungal and cell wall-damaging agents and was also attenuated in virulence. Although a mutant lacking the downstream transcription factor Crz1 displayed a cell wall-associated phenotype intermediate to that of the calcineurin mutant and was modestly attenuated in virulence, it did not show increased azole susceptibility. These results suggest that calcineurin regulates both Crz1-dependent and -independent pathways depending on the type of stress. PMID:20100876

Antifungal Effect of Novel 2-Bromo-2-Chloro-2-(4-Chlorophenylsulfonyl)-1-Phenylethanone against Candida Strains

PubMed Central

Staniszewska, Monika; Bondaryk, Małgorzata; Wieczorek, Magdalena; Estrada-Mata, Eine; Mora-Montes, Héctor M.; Ochal, Zbigniew

2016-01-01

We investigated the antifungal activity of novel a 2-bromo-2-chloro-2-(4-chlorophenylsulfonyl)-1-phenylethanone (compound 4). The synthesis of compound 4 was commenced from sodium 4-chlorobenzene sulfinate and the final product was obtained by treatment of α-chloro-β-keto-sulfone with sodium hypobromite. The sensitivity of 63 clinical isolates belonging to the most relevant Candida species toward compound 4 using the method M27-A3 was evaluated. We observed among most of the clinical strains of C. albicans MIC ranging from 0.00195 to 0.0078 μg/mL. Compound 4 at 32 μg/mL exhibited fungicidal activity against nine Candida strains tested using the MFC assay. Compound 4 displayed anti-Candida activity (with clear endpoint) against 22% of clinical strains of Candida. Under compound 4, Candida susceptibility and tolerance, namely paradoxical effect (PG), was found for only two clinical isolates (C. glabrata and C. parapsilosis) and reference strain 14053 using both M27-A3 and MFC method. We found that compound 4 does not induce toxicity in vivo against larvae of Galleria mellonella (≥97% survival) and it displays reduced toxicity on mammalian cells in vitro (< CC20 at 64 μg/mL). Furthermore, XTT assay denoted clear metabolic activity of sessile cells in the presence of compound 4. Thus, the effect of compound 4 on formed C. albicans biofilms was minimal. Moreover, strain 90028 exhibited no defects in hyphal growth on Caco-2 monolayer under compound 4 influence at MIC = 16 μg/mL. The MIC values of compound 4 against C. albicans 90028, in medium with sorbitol did not suggest that compound 4 acts by inhibiting fungal cell wall synthesis. Our findings with compound 4 suggest a general strategy for antifungal agent development that might be useful in limiting the emergence of resistance in Candida strains. PMID:27610100

Production of ethanol from infant food formulas by common yeasts.

PubMed

Bivin, W S; Heinen, B N

1985-04-01

Four common yeasts (Candida albicans, Candida tropicalis, Torulopsis glabrata and Saccharomyces cerevisiae) were combined with five infant food formulas and/or supplements (Isomil, Nutramigen, 5% glucose, Coca Cola and Similac) and incubated at 37 degrees C. Gas chromatography was used to measure ethanol production after 24 and 48 h incubation. The quantities of ethanol produced suggest a possible explanation for patients exhibiting the 'Auto-Brewery Syndrome' and raises interest in the role auto-produced ethanol could have in explaining the etiology of Sudden Infant Death.

Abdominal candidiasis is a hidden reservoir of echinocandin resistance.

PubMed

Shields, Ryan K; Nguyen, M Hong; Press, Ellen G; Clancy, Cornelius J

2014-12-01

FKS mutant Candida isolates were recovered from 24% (6/25) of abdominal candidiasis patients exposed to echinocandin. Candida glabrata (29%) and Candida albicans (14%) mutants were identified. Multidrug-resistant bacteria were recovered from 83% of FKS mutant infections. Mutations were associated with prolonged echinocandin exposure (P = 0.01), breakthrough infections (P = 0.03), and therapeutic failures despite source control interventions (100%). Abdominal candidiasis is a hidden reservoir for the emergence of echinocandin-resistant Candida. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

KSC-98pc409

NASA Image and Video Library

1998-03-11

KENNEDY SPACE CENTER, FLA. -- A water snail (Biomphalaria glabrata), like those that are part of the Neurolab payload on Space Shuttle Mission STS-90, is held up for inspection in the Operations and Checkout Building. The snails will fly in the Closed Equilibrated Biological Aquatic System (CEBAS) Minimodule, a middeck locker-sized fresh water habitat, designed to allow the controlled incubation of aquatic species in a self-stabilizing, artifical ecosystem for up to three weeks under space conditions. Investigations during the Neurolab mission will focus on the effects of microgravity on the nervous system. The crew of STS-90, slated for launch April 16 at 2:19 p.m. EDT, includes Commander Richard Searfoss, Pilot Scott Altman, Mission Specialists Richard Linnehan, D.V.M., Dafydd (Dave) Williams, M.D., and Kathryn (Kay) Hire, and Payload Specialists Jay Buckey, M.D., and James Pawelczyk, Ph.D