In vitro phagocytosis of several Candida berkhout species by murine leukocytes.

PubMed

Fontenla de Petrino, S E; Bibas Bonet de Jorrat, M E; Sirena, A

1985-03-01

In vitro phagocytosis of thirteen Candida berkhout species by rat leukocytes was studied to assess a possible correlation between pathogenicity and phagocytosis Yeast-leukocyte suspensions were mixed up for 3 h and phagocytic index, germ-tube formation and leukocyte candidacidal activity were evaluated. Highest values for phagocytosis were reached in all cases at the end of the first hour. Leukocyte candidacidal activity was absent. Only C. albicans produced germ-tubes. The various phagocytosis indices were determined depending on the Candida species assayed. Under these conditions, the more pathogenic species presented the lower indices of phagocytosis. It is determined that the in vitro phagocytic index may bear a close relationship with the pathogenicity of the Candida berkhout.

Plants’ Natural Products as Alternative Promising Anti-Candida Drugs

PubMed Central

Soliman, Sameh; Alnajdy, Dina; El-Keblawy, Ali A.; Mosa, Kareem A.; Khoder, Ghalia; Noreddin, Ayman M.

2017-01-01

Candida is a serious life-threatening pathogen, particularly with immunocompromised patients. Candida infections are considered as a major cause of morbidity and mortality in a broad range of immunocompromised patients. Candida infections are common in hospitalized patients and elderly people. The difficulty to eradicate Candida infections is owing to its unique switch between yeast and hyphae forms and more likely to biofilm formations that render resistance to antifungal therapy. Plants are known sources of natural medicines. Several plants show significant anti-Candida activities and some of them have lower minimum inhibitory concentration, making them promising candidates for anti-Candida therapy. However, none of these plant products is marketed for anti-Candida therapy because of lack of sufficient information about their efficacy, toxicity, and kinetics. This review revises major plants that have been tested for anti-Candida activities with recommendations for further use of some of these plants for more investigation and in vivo testing including the use of nanostructure lipid system. PMID:28989245

Psoriasin, a novel anti-Candida albicans adhesin.

PubMed

Brauner, Annelie; Alvendal, Cathrin; Chromek, Milan; Stopsack, Konrad H; Ehrström, Sophia; Schröder, Jens M; Bohm-Starke, Nina

2018-05-07

Candida albicans belongs to the normal microbial flora on epithelial surfaces of humans. However, under certain, still not fully understood conditions, it can become pathogenic and cause a spectrum of diseases, from local infections to life-threatening septicemia. We investigated a panel of antimicrobial proteins and peptides (AMPs), potentially involved in mucosal immunity against this pathogen. Out of six studied AMPs, psoriasin was most up-regulated during a mucosal infection, an acute episode of recurrent Candida vulvovaginitis, although candidacidal activity has not been demonstrated. We here show that psoriasin binds to β-glucan, a basic component of the C. albicans cell wall, and thereby inhibits adhesion of the pathogen to surfaces and increases IL-8 production by mucosal epithelial cells. In conclusion, we show a novel mechanism of action of psoriasin. By inhibiting C. albicans adhesion and by enhancing cytokine production, psoriasin contributes to the immune response against C. albicans. The antimicrobial peptide psoriasin is highly up-regulated during a local mucosal infection, Candida albicans vulvovaginitis. Psoriasin binds to β-glucan in the Candida albicans cell wall and thereby inhibits adhesion of the pathogen. Binding of psoriasin to Candida albicans induces an immune response by mucosal epithelial cells.

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

Intestinal colonization with Candida albicans and mucosal immunity

PubMed Central

Bai, Xiao-Dong; Liu, Xian-Hua; Tong, Qing-Ying

2004-01-01

AIM: To observe the relationship between intestinal lumen colonization with Candida albicans and mucosal secretory IgA (sIgA). METHODS: A total of 82 specific-pathogen-free mice were divided randomly into control and colonization groups. After Candida albicans were inoculated into specific-pathogen-free mice, the number of Candida albicans adhering to cecum and mucosal membrane was counted. The lymphocyte proliferation in Peyer’s patch and in lamina propria was shown by BrdU incorporation, while mucosal sIgA (surface membrane) isotype switch in Peyer’s patch was investigated. IgA plasma cells in lamina propria were observed by immunohistochemical staining. Specific IgA antibodies to Candida albicans were measured with ELISA. RESULTS: From d 3 to d 14 after Candida albicans gavaging to mice, the number of Candida albicans colonizing in lumen and adhering to mucosal membrane was sharply reduced. Candida albicans translocation to mesenteric lymph nodes occurred at early time points following gavage administration and disappeared at later time points. Meanwhile, the content of specific IgA was increased obviously. Proliferation and differentiation of lymphocytes in lamina propria were also increased. CONCLUSION: Lymphocytes in lamina propria play an important role in intestinal mucosal immunity of specific-pathogen-free mice when they are first inoculated with Candida albicans. The decreasing number of Candida albicans in intestine is related to the increased level of specific IgA antibodies in the intestinal mucus. PMID:15237449

IL-27 Induced by Select Candida spp. via TLR7/NOD2 Signaling and IFN-β Production Inhibits Fungal Clearance

PubMed Central

Patin, Emmanuel C.; Jones, Adam V.; Thompson, Aiysha; Clement, Mathew; Liao, Chia-Te; Griffiths, James S.; Wallace, Leah E.; Bryant, Clare E.; Lang, Roland; Rosenstiel, Philip; Humphreys, Ian R.; Taylor, Philip R.

2016-01-01

Candida spp. elicit cytokine production downstream of various pathogen recognition receptors, including C-type lectin-like receptors, TLRs, and nucleotide oligomerization domain (NOD)–like receptors. IL-12 family members IL-12p70 and IL-23 are important for host immunity against Candida spp. In this article, we show that IL-27, another IL-12 family member, is produced by myeloid cells in response to selected Candida spp. We demonstrate a novel mechanism for Candida parapsilosis–mediated induction of IL-27 in a TLR7-, MyD88-, and NOD2-dependent manner. Our data revealed that IFN-β is induced by C. parapsilosis, which in turn signals through the IFN-α/β receptor and STAT1/2 to induce IL-27. Moreover, IL-27R (WSX-1)–deficient mice systemically infected with C. parapsilosis displayed enhanced pathogen clearance compared with wild-type mice. This was associated with increased levels of proinflammatory cytokines in the serum and increased IFN-γ and IL-17 responses in the spleens of IL-27R–deficient mice. Thus, our data define a novel link between C. parapsilosis, TLR7, NOD2, IFN-β, and IL-27, and we have identified an important role for IL-27 in the immune response against C. parapsilosis. Overall, these findings demonstrate an important mechanism for the suppression of protective immune responses during infection with C. parapsilosis, which has potential relevance for infections with other fungal pathogens. PMID:27259855

In vitro antifungal activity of different components of Centratherum anthelminticum and Ocimum sanctum seed oils and their synergism against oral pathogenic fungi

PubMed Central

H Gopalkrishna, Aparna; M, Seshagiri; Muddaiah, Sunil; R, Shashidara

2016-01-01

Background. Opportunistic fungal infections like candidiasis are common in the oral cavity. In recent years Candida species have shown resistance against a number of synthetic drugs. This study assessed the antifungal activity of Centratherum anthelminticum and Ocimum sanctum seed oils against six common pathogenic Candida strains. Synergistic activity of the major oil components was also studied. Methods. Antifungal activity of Centratherum anthelminticum and Ocimum sanctum seed oils were tested against six oral fungal pathogens, Candida albicans ATCC 90028, Candida krusei 6258, Candida tropicalis 13803, Candida parapsilosis22019, Candida glabrata 90030 and Candida dubliniensis MYA 646, by disc diffusion and broth microdilution methods to determine the diameter of inhibition zone (DIZ) and minimum inhibitory concentration (MIC), respectively. The oil was extracted using Soxhlet apparatus from seeds subjected to columnchromatography (CC) and thin layer chromatography (TLC) and major components were separated and quantified. Results. All the six Candida strains showed growth inhibition to a variable degree when tested with both seed oils. Both seed oils showed antifungal activity. For Centratherum anthelminticum seed oil maximum DIZ at 7 μL was recorded at 75.7 mm for Candida albicans ATCC 90028, and the least DIZ was 45.7 mm for Candida dubliniensis MYA 646. For Ocimum sanctum seed oil maximum DIZ at 7 μL was 61.0 mm for Candida krusei ATCC 6258 and the least DIZ was 46.7 mm for Candida tropicalis ATCC 13803. The mixtures of phospholipids and unsaponifiable matter exhibitedMIC values at 1.25 μL for both oils, whereas neutral lipids fraction and unsaponifiable matter exhibited similar MIC at 2.5 μL against Candida albicans and Candida krusei. Conclusion.Centratherum anthelminticum and Ocimum sanctumseed oils exhibited strong antifungal activity against six different species of Candida and this may be attributed to various active components in the oil and their synergistic activity. PMID:27429725

A CTG Clade Candida Yeast Genetically Engineered for the Genotype-Phenotype Characterization of Azole Antifungal Resistance in Human-Pathogenic Yeasts.

PubMed

Accoceberry, Isabelle; Rougeron, Amandine; Biteau, Nicolas; Chevrel, Pauline; Fitton-Ouhabi, Valérie; Noël, Thierry

2018-01-01

A strain of the opportunistic pathogenic yeast Candida lusitaniae was genetically modified for use as a cellular model for assessing by allele replacement the impact of lanosterol C14α-demethylase ERG11 mutations on azole resistance. Candida lusitaniae was chosen because it is susceptible to azole antifungals, it belongs to the CTG clade of yeast, which includes most of the Candida species pathogenic for humans, and it is haploid and easily amenable to genetic transformation and molecular modeling. In this work, allelic replacement is targeted at the ERG11 locus by the reconstitution of a functional auxotrophic marker in the 3' intergenic region of ERG11 Homologous and heterologous ERG11 alleles are expressed from the resident ERG11 promoter of C. lusitaniae , allowing accurate comparison of the phenotypic change in azole susceptibility. As a proof of concept, we successfully expressed in C. lusitaniae different ERG11 alleles, either bearing or not bearing mutations retrieved from a clinical context, from two phylogenetically distant yeasts, C. albicans and Kluyveromyces marxianus Candida lusitaniae constitutes a high-fidelity expression system, giving specific Erg11p-dependent fluconazole MICs very close to those observed with the ERG11 donor strain. This work led us to characterize the phenotypic effect of two kinds of mutation: mutation conferring decreased fluconazole susceptibility in a species-specific manner and mutation conferring fluconazole resistance in several yeast species. In particular, a missense mutation affecting amino acid K143 of Erg11p in Candida species, and the equivalent position K151 in K. marxianus , plays a critical role in fluconazole resistance. Copyright © 2017 American Society for Microbiology.

Gene flow contributes to diversification of the major fungal pathogen Candida albicans.

PubMed

Ropars, Jeanne; Maufrais, Corinne; Diogo, Dorothée; Marcet-Houben, Marina; Perin, Aurélie; Sertour, Natacha; Mosca, Kevin; Permal, Emmanuelle; Laval, Guillaume; Bouchier, Christiane; Ma, Laurence; Schwartz, Katja; Voelz, Kerstin; May, Robin C; Poulain, Julie; Battail, Christophe; Wincker, Patrick; Borman, Andrew M; Chowdhary, Anuradha; Fan, Shangrong; Kim, Soo Hyun; Le Pape, Patrice; Romeo, Orazio; Shin, Jong Hee; Gabaldon, Toni; Sherlock, Gavin; Bougnoux, Marie-Elisabeth; d'Enfert, Christophe

2018-06-08

Elucidating population structure and levels of genetic diversity and recombination is necessary to understand the evolution and adaptation of species. Candida albicans is the second most frequent agent of human fungal infections worldwide, causing high-mortality rates. Here we present the genomic sequences of 182 C. albicans isolates collected worldwide, including commensal isolates, as well as ones responsible for superficial and invasive infections, constituting the largest dataset to date for this major fungal pathogen. Although, C. albicans shows a predominantly clonal population structure, we find evidence of gene flow between previously known and newly identified genetic clusters, supporting the occurrence of (para)sexuality in nature. A highly clonal lineage, which experimentally shows reduced fitness, has undergone pseudogenization in genes required for virulence and morphogenesis, which may explain its niche restriction. Candida albicans thus takes advantage of both clonality and gene flow to diversify.

Beyond Candida albicans: Mechanisms of immunity to non-albicans Candida species

PubMed Central

Whibley, Natasha; Gaffen, Sarah L.

2015-01-01

The fungal genus Candida encompasses numerous species that inhabit a variety of hosts, either as commensal microbes and/or pathogens. Candida species are a major cause of fungal infections, yet to date there are no vaccines against Candida or indeed any other fungal pathogen. Our knowledge of immunity to Candida mainly comes from studies on C. albicans, the most frequent species associated with disease. However, non-albicans Candida (NAC) species also cause disease and their prevalence is increasing. Although research into immunity to NAC species is still at an early stage, it is becoming apparent that immunity to C. albicans differs in important ways from non-albicans species, with important implications for treatment, therapy and predicted demographic susceptibility. This review will discuss the current understanding of immunity to NAC species in the context of immunity to C. albicans, and highlight as-yet unanswered questions. PMID:26276374

Use of CHROMagar Candida for the presumptive identification of Candida species directly from clinical specimens in resource-limited settings.

PubMed

Nadeem, Sayyada Ghufrana; Hakim, Shazia Tabassum; Kazmi, Shahana Urooj

2010-02-09

Identification of yeast isolated from clinical specimens to the species level has become increasingly important. Ever-increasing numbers of immuno-suppressed patients, a widening range of recognized pathogens, and the discovery of resistance to antifungal drugs are contributing factors to this necessity. A total of 487 yeast strains were studied for the primary isolation and presumptive identification, directly from clinical specimen. Efficacy of CHROMagar Candida has been evaluated with conventional methods including morphology on Corn meal-tween 80 agar and biochemical methods by using API 20 C AUX. The result of this study shows that CHROMagar Candida can easily identify three species of Candida on the basis of colonial color and morphology, and accurately differentiate between them i.e. Candida albicans, Candida tropicalis, and Candida krusei. The specificity and sensitivity of CHROMagar Candida for C. albicans calculated as 99%, for C. tropicalis calculated as 98%, and C. krusei it is 100%. The data presented supports the use of CHROMagar Candida for the rapid identification of Candida species directly from clinical specimens in resource-limited settings, which could be very helpful in developing appropriate therapeutic strategy and management of patients.

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.

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.

Budding off: bringing functional genomics to Candida albicans

PubMed Central

Anderson, Matthew Z.

2016-01-01

Candida species are the most prevalent human fungal pathogens, with Candida albicans being the most clinically relevant species. Candida albicans resides as a commensal of the human gastrointestinal tract but is a frequent cause of opportunistic mucosal and systemic infections. Investigation of C. albicans virulence has traditionally relied on candidate gene approaches, but recent advances in functional genomics have now facilitated global, unbiased studies of gene function. Such studies include comparative genomics (both between and within Candida species), analysis of total RNA expression, and regulation and delineation of protein–DNA interactions. Additionally, large collections of mutant strains have begun to aid systematic screening of clinically relevant phenotypes. Here, we will highlight the development of functional genomics in C. albicans and discuss the use of these approaches to addressing both commensalism and pathogenesis in this species. PMID:26424829

[Antimycotic activity in vitro and in vivo of 5-fluorocytosine on pathogenic strains of Candida albicans and Cryptococcus neoformans].

PubMed

Costa, A L; Valenti, A; Costa, G; Calogero, F

1976-01-01

The authors have analyzed the 5 Fluoro Cytosine (5FC) activity on strains of Candida albicans and Criptococcus neoformans, both in vitro and in vivo. In vitro the minimal inhibitory concentration (MIC) was determined; in vivo tests of pathogenicity on rabbit and mouse have been executed. The various findings obtained have shown a strong activity of the 5FC on strains of Candida and Criptococcus.

Azole drugs are imported by facilitated diffusion in Candida albicans and other pathogenic fungi.

PubMed

Mansfield, Bryce E; Oltean, Hanna N; Oliver, Brian G; Hoot, Samantha J; Leyde, Sarah E; Hedstrom, Lizbeth; White, Theodore C

2010-09-30

Despite the wealth of knowledge regarding the mechanisms of action and the mechanisms of resistance to azole antifungals, very little is known about how the azoles are imported into pathogenic fungal cells. Here the in-vitro accumulation and import of Fluconazole (FLC) was examined in the pathogenic fungus, Candida albicans. In energized cells, FLC accumulation correlates inversely with expression of ATP-dependent efflux pumps. In de-energized cells, all strains accumulate FLC, suggesting that FLC import is not ATP-dependent. The kinetics of import in de-energized cells displays saturation kinetics with a K(m) of 0.64 μM and V(max) of 0.0056 pmol/min/10⁸ cells, demonstrating that FLC import proceeds via facilitated diffusion through a transporter rather than passive diffusion. Other azoles inhibit FLC import on a mole/mole basis, suggesting that all azoles utilize the same facilitated diffusion mechanism. An analysis of related compounds indicates that competition for azole import depends on an aromatic ring and an imidazole or triazole ring together in one molecule. Import of FLC by facilitated diffusion is observed in other fungi, including Cryptococcus neoformans, Saccharomyces cerevisiae, and Candida krusei, indicating that the mechanism of transport is conserved among fungal species. FLC import was shown to vary among Candida albicans resistant clinical isolates, suggesting that altered facilitated diffusion may be a previously uncharacterized mechanism of resistance to azole drugs.

EVALUATION OF 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 (trademark)) chemistry, was developed for the specific detection and quantification of six pathogenic species of Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis, C. glab...

Comparative Evolution of Morphological Regulatory Functions in Candida Species

PubMed Central

Lackey, Erika; Vipulanandan, Geethanjali; Childers, Delma S.

2013-01-01

Morphological transitions play an important role in virulence and virulence-related processes in a wide variety of pathogenic fungi, including the most commonly isolated human fungal pathogen Candida albicans. While environmental signals, transcriptional regulators, and target genes associated with C. albicans morphogenesis are well-characterized, considerably little is known about morphological regulatory mechanisms and the extent to which they are evolutionarily conserved in less pathogenic and less filamentous non-albicans Candida species (NACS). We have identified specific optimal filament-inducing conditions for three NACS (C. tropicalis, C. parapsilosis, and C. guilliermondii), which are very limited, suggesting that these species may be adapted for niche-specific filamentation in the host. Only a subset of evolutionarily conserved C. albicans filament-specific target genes were induced upon filamentation in C. tropicalis, C. parapsilosis, and C. guilliermondii. One of the genes showing conserved expression was UME6, a key filament-specific regulator of C. albicans hyphal development. Constitutive high-level expression of UME6 was sufficient to drive increased filamentation as well as biofilm formation and partly restore conserved filament-specific gene expression in both C. tropicalis and C. parapsilosis, suggesting that evolutionary differences in filamentation ability among pathogenic Candida species may be partially attributed to alterations in the expression level of a conserved filamentous growth machinery. In contrast to UME6, NRG1, an important repressor of C. albicans filamentation, showed only a partly conserved role in controlling NACS filamentation. Overall, our results suggest that C. albicans morphological regulatory functions are partially conserved in NACS and have evolved to respond to more specific sets of host environmental cues. PMID:23913541

Manipulation of host diet to reduce gastrointestinal colonization by the opportunistic pathogen Candida albicans

USDA-ARS?s Scientific Manuscript database

Candida albicans, the most common human fungal pathogen, can cause systemic infections with a mortality rate of ~40%. Infections arise from colonization of the gastrointestinal (GI) tract, where C. albicans is part of the normal microflora. Reducing colonization in at-risk patients using antifungal ...

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....

Mixed Fungal Lung Infection with Aspergillus Fumigatus and Candida Albicans in a Immunocomprimised Patient: Case Report

PubMed Central

Vipparti, Haritha

2014-01-01

The frequency of invasive, opportunistic mycoses has increased significantly over the past 2 decades. In the immune-compromised host, many fungi, including species of fungi typically considered non-pathogenic, have the potential to cause serious morbidity and mortality. Here we report a rare case of mixed fungal infection of the lung with Candida albicans and Aspergillus fumigatus in a patient on prolonged steroid therapy. PMID:24959447

Candida Parapsilosis and Candida Guillermondii: Emerging Pathogens in Nail Candidiasis

PubMed Central

Fich, Felix; Abarzúa-Araya, Alvaro; Pérez, Mario; Nauhm, Yalile; León, Eugenia

2014-01-01

Background: Onychomycosis of the fingernails and toenails is generally caused by dermatophytes and yeasts. Toenail mycoses involve mainly dermatophytes but when Candida is also involved, the strain most commonly isolated worldwide is C. albicans. Aims: To determine Candida strains prevailing in onychomycosis. Materials and Methods: A retrospective, observational and descriptive study of fungal cultures retrieved from the registry of the microbiology laboratory of the Pontificia Universidad Católica was performed. Specimens obtained from patients attending the healthcare network between December 2007 and December 2010 was analyzed. Statistical Analysis: A descriptive statistical analysis was performed. Results: Candida was retrieved from 467 of 8443 specimens (52% fingernails and 48% toenails). Cultures were negative in 5320 specimens (63.6%). Among Candida-positive cultures, parapsilosis was the most commonly isolated strain with 202 cases (43.3%). While isolates of Candida guillermondii were 113 (24.2%), those of Candida albicans were 110 (23.6%), those of spp. were 20 (4.3%) and there were 22 cases of other isolates (4.71%). Among the 467 patients with positive cultures for Candida, 136 (29,1%) were men and 331 (70,9%) were women. All patients were older than 18 years old. Clinical files were available for only 169 of the 467 patients with positive cultures for Candida. For those, age, gender, underlying illnesses and use of immunossupresive agents during the trial was reviewed. Conclusions: The present study shows that both C. parapsilosis as well as C. guillermondii appear as emerging pathogens that would be in fact taking the place of C. albicans as the most commonly isolated pathogen in patients with Candida onychomycosis. The relative percentage of C parapsilosis increases every year. Identification of Candida strains as etiological agents of nail candidiasis becomes relevant to the management both nail as well as systemic candidiasis, in view of the resistance to conventional treatments readily reported in the literature. PMID:24470656

Budding off: bringing functional genomics to Candida albicans.

PubMed

Anderson, Matthew Z; Bennett, Richard J

2016-03-01

Candida species are the most prevalent human fungal pathogens, with Candida albicans being the most clinically relevant species. Candida albicans resides as a commensal of the human gastrointestinal tract but is a frequent cause of opportunistic mucosal and systemic infections. Investigation of C. albicans virulence has traditionally relied on candidate gene approaches, but recent advances in functional genomics have now facilitated global, unbiased studies of gene function. Such studies include comparative genomics (both between and within Candida species), analysis of total RNA expression, and regulation and delineation of protein-DNA interactions. Additionally, large collections of mutant strains have begun to aid systematic screening of clinically relevant phenotypes. Here, we will highlight the development of functional genomics in C. albicans and discuss the use of these approaches to addressing both commensalism and pathogenesis in this species. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

[Presumptive identification of Candida spp. and other clinically important yeasts: usefulness of Brilliance Candida Agar].

PubMed

Alfonso, Claudia; López, Mónica; Arechavala, Alicia; Perrone, María Del Carmen; Guelfand, Liliana; Bianchi, Mario

2010-06-30

Fungal infections caused by yeasts have increased during the last decades and invasive forms represent a serious problem for human health. Candida albicans is the species most frequently isolated from clinical samples. However, other emerging yeast pathogens are increasingly responsible for mycotic infections, and some of them are resistant to some antifungal drugs. Consequently, it is necessary to have methods that can provide a rapid presumptive identification at species level. Numerous chromogenic agar media have been shown to be of value as diagnostic tools. We have compared a chromogenic medium, Brilliance Candida Agar, with CHROMagar Candida, the chromogenic medium most used in our country. A multicentre study was conducted in 16 Hospitals belonging to the Mycology Net of Buenos Aires City Government. A total of 240 yeast isolates were included in this research. The new chromogenic agar showed results very similar to those obtained with CHROMagar Candida. Copyright 2009 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Characterization and Reclassification of Yeasts Used for Biological Control of Postharvest Diseases of Fruits and Vegetables

PubMed Central

McLaughlin, R. J.; Wilson, C. L.; Chalutz, E.; Kurtzman, C. P.; Fett, W. F.; Osman, S. F.

1990-01-01

In previous studies workers have shown that three yeast strains (strains US-7, 82, and 101) have biological control activity against various postharvest fungal pathogens of fruits and vegetables, including Penicillium rots of apples and citrus and Botrytis rot of apples. In these reports the researchers have described these strains as Debaryomyces hansenii (anamorph, Candida famata) or Candida sp. strains. In this study we performed additional physiological, DNA reassociation, and mannan characterization tests that clearly established a new taxonomic classification for these strains, Candida guilliermondii. We also propose amendment of the physiological test profile in the taxonomic description of C. guilliermondii. PMID:16348361

Oral candidiasis in immunosuppressed children and young adults after liver or kidney transplantation.

PubMed

Olczak-Kowalczyk, Dorota; Pawłowska, Joanna; Garczewska, Barbara; Smirska, Ewa; Grenda, Ryszard; Syczewska, Małgorzata; Kowalczyk, Wojciech

2010-01-01

Candidiasis is an infectious complication in organ transplant recipients resulting from the patients' immunodeficiency and virulence of fungi pathogens. The purpose of this study was to evaluate the frequency of Candida spp. and identify their presence in the oral lesions of graft recipients. This study included 185 patients, 1.5 to 25.2 years of age (mean = 13.1 +/- 4.2 years) who were receiving combined immunosuppression treatment after kidney or liver transplantation and 70 control subjects. Evaluation included clinical oral examination, mycology, and statistical analysis. Candida spp. colonies were found in the oral mucosa of 63 (34%) graft recipients and in 19 (27%) control subjects. Candida albicans was the most prevalent species. This study showed that, regardless of the type of the organ transplant and immunosuppression, frequent, regular oral follow-up and mycologic tests are recommended. Diagnosing increased density of Candida spp. colonies in the oral cavity will help initiate early antifungal treatment. Candida spp. prevalence in the oral cavity in transplant recipients was higher than in immunocompetent control subjects. Kidney or liver transplantation predisposes one to the development of an increased density of Candida spp. colonies.

Pathogenic characteristics of Candida albicans isolated from oral cavities of denture wearers and cancer patients wearing oral prostheses.

PubMed

Mothibe, J V; Patel, M

2017-09-01

Candida albicans cause opportunistic infections including oral candidiasis in immunocompromised patients. It has an ability to cause infection due to its virulence factors. This study investigated the pathogenic characteristics of C. albicans isolated from the oral cavities of healthy subjects and two vulnerable groups, denture wearers and cancer patients wearing oral prostheses. Oral rinse samples were collected and cultured for the quantitative and qualitative analysis of Candida. Twenty strains of C. albicans isolated from the healthy individuals and denture wearers and, 14 strains isolated from the cancer patients were selected and their pathogenic characteristics were measured. The results of the study groups were compared using a Scheffe test for pairwise comparison and a chi square test. Denture wearer and cancer patients with prostheses carried significantly higher number (p < 0.01) and a variety of Candida than the normal individuals. Denture wearer and cancer patients carried several Candida species. The adherence abilities (p = 0.01) as well as phospholipase (p < 0.01) and proteinase (p = 0.03) production were significantly higher in the strains from denture wearers. In addition, high number of isolates from the denture wearers produced phospholipase and proteinase (85% and 80% respectively) compared to the strains from normal subjects (25% and 60% respectively). Only the germ tube formation and adherence ability were significantly higher in the strains from the cancer patients with prostheses (p = 0.05 and p < 0.01 respectively). In conclusion, during the commensal state, the increased expression of virulence factors in the denture wearers suggests the readiness of these strains to cause infection in this group. The high number of C. albicans and their increased adherence ability in the two study groups suggest that hygiene of oral cavity and prostheses is important in the prevention of colonization of Candida and the development of oral candidiasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structural analyses of Candida albicans sterol 14α-demethylase complexed with azole drugs address the molecular basis of azole-mediated inhibition of fungal sterol biosynthesis

PubMed Central

Hargrove, Tatiana Y.; Friggeri, Laura; Wawrzak, Zdzislaw; Qi, Aidong; Hoekstra, William J.; Schotzinger, Robert J.; York, John D.; Guengerich, F. Peter; Lepesheva, Galina I.

2017-01-01

With some advances in modern medicine (such as cancer chemotherapy, broad exposure to antibiotics, and immunosuppression), the incidence of opportunistic fungal pathogens such as Candida albicans has increased. Cases of drug resistance among these pathogens have become more frequent, requiring the development of new drugs and a better understanding of the targeted enzymes. Sterol 14α-demethylase (CYP51) is a cytochrome P450 enzyme required for biosynthesis of sterols in eukaryotic cells and is the major target of clinical drugs for managing fungal pathogens, but some of the CYP51 key features important for rational drug design have remained obscure. We report the catalytic properties, ligand-binding profiles, and inhibition of enzymatic activity of C. albicans CYP51 by clinical antifungal drugs that are used systemically (fluconazole, voriconazole, ketoconazole, itraconazole, and posaconazole) and topically (miconazole and clotrimazole) and by a tetrazole-based drug candidate, VT-1161 (oteseconazole: (R)-2-(2,4-difluorophenyl)-1,1-difluoro-3-(1H-tetrazol-1-yl)-1-(5-(4-(2,2,2-trifluoroethoxy)phenyl)pyridin-2-yl)propan-2-ol). Among the compounds tested, the first-line drug fluconazole was the weakest inhibitor, whereas posaconazole and VT-1161 were the strongest CYP51 inhibitors. We determined the X-ray structures of C. albicans CYP51 complexes with posaconazole and VT-1161, providing a molecular mechanism for the potencies of these drugs, including the activity of VT-1161 against Candida krusei and Candida glabrata, pathogens that are intrinsically resistant to fluconazole. Our comparative structural analysis outlines phylum-specific CYP51 features that could direct future rational development of more efficient broad-spectrum antifungals. PMID:28258218

Structural analyses of Candida albicans sterol 14α-demethylase complexed with azole drugs address the molecular basis of azole-mediated inhibition of fungal sterol biosynthesis.

PubMed

Hargrove, Tatiana Y; Friggeri, Laura; Wawrzak, Zdzislaw; Qi, Aidong; Hoekstra, William J; Schotzinger, Robert J; York, John D; Guengerich, F Peter; Lepesheva, Galina I

2017-04-21

With some advances in modern medicine (such as cancer chemotherapy, broad exposure to antibiotics, and immunosuppression), the incidence of opportunistic fungal pathogens such as Candida albicans has increased. Cases of drug resistance among these pathogens have become more frequent, requiring the development of new drugs and a better understanding of the targeted enzymes. Sterol 14α-demethylase (CYP51) is a cytochrome P450 enzyme required for biosynthesis of sterols in eukaryotic cells and is the major target of clinical drugs for managing fungal pathogens, but some of the CYP51 key features important for rational drug design have remained obscure. We report the catalytic properties, ligand-binding profiles, and inhibition of enzymatic activity of C. albicans CYP51 by clinical antifungal drugs that are used systemically (fluconazole, voriconazole, ketoconazole, itraconazole, and posaconazole) and topically (miconazole and clotrimazole) and by a tetrazole-based drug candidate, VT-1161 (oteseconazole: ( R )-2-(2,4-difluorophenyl)-1,1-difluoro-3-(1 H -tetrazol-1-yl)-1-(5-(4-(2,2,2-trifluoroethoxy)phenyl)pyridin-2-yl)propan-2-ol). Among the compounds tested, the first-line drug fluconazole was the weakest inhibitor, whereas posaconazole and VT-1161 were the strongest CYP51 inhibitors. We determined the X-ray structures of C. albicans CYP51 complexes with posaconazole and VT-1161, providing a molecular mechanism for the potencies of these drugs, including the activity of VT-1161 against Candida krusei and Candida glabrata , pathogens that are intrinsically resistant to fluconazole. Our comparative structural analysis outlines phylum-specific CYP51 features that could direct future rational development of more efficient broad-spectrum antifungals. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The immune response against Candida spp. and Sporothrix schenckii.

PubMed

Martínez-Álvarez, José A; Pérez-García, Luis A; Flores-Carreón, Arturo; Mora-Montes, Héctor M

2014-01-01

Candida albicans is the main causative agent of systemic candidiasis, a condition with high mortality rates. The study of the interaction between C. albicans and immune system components has been thoroughly studied and nowadays there is a model for the anti-C. albicans immune response; however, little is known about the sensing of other pathogenic species of the Candida genus. Sporothrix schenckii is the causative agent of sporotrichosis, a subcutaneous mycosis, and thus far there is limited information about its interaction with the immune system. In this paper, we review the most recent information about the immune sensing of species from genus Candida and S. schenckii. Thoroughly searches in scientific journal databases were performed, looking for papers addressing either Candida- or Sporothrix-immune system interactions. There is a significant advance in the knowledge of non-C. albicans species of Candida and Sporothrix immune sensing; however, there are still relevant points to address, such as the specific contribution of pathogen-associated molecular patterns (PAMPs) for sensing by different immune cells and the immune receptors involved in such interactions. 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.

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

Molecular genetic techniques for gene manipulation in Candida albicans.

PubMed

Xu, Qiu-Rong; Yan, Lan; Lv, Quan-Zhen; Zhou, Mi; Sui, Xue; Cao, Yong-Bing; Jiang, Yuan-Ying

2014-05-15

Candida albicans is one of the most common fungal pathogen in humans due to its high frequency as an opportunistic and pathogenic fungus causing superficial as well as invasive infections in immunocompromised patients. An understanding of gene function in C. albicans is necessary to study the molecular basis of its pathogenesis, virulence and drug resistance. Several manipulation techniques have been used for investigation of gene function in C. albicans, including gene disruption, controlled gene expression, protein tagging, gene reintegration, and overexpression. In this review, the main cassettes containing selectable markers used for gene manipulation in C. albicans are summarized; the advantages and limitations of these cassettes are discussed concerning the influences on the target gene expression and the virulence of the mutant strains.

A diterpenoid taxodone from Metasequoia glyptostroboides with antimycotic potential against clinical isolates of Candida species.

PubMed

Bajpai, V K; Park, Y-H; Kang, S C

2015-03-01

The increasing importance of clinical isolates of Candida species and emerging resistance of Candida species to current synthetic antifungal agents have stimulated the search for safer and more effective alternative drugs from natural sources. This study was directed towards exploring the antimycotic potential of a diterpenoid compound taxodone isolated from Metasequoia glyptostroboides against pathogenic isolates of Candida species. Antimycotic efficacy of taxodone was evaluated by disc diffusion assay, determination of minimum inhibitory (MIC) and minimum fungicidal (MFC) concentrations, and cell viability assay. To confirm a partial antimycotic mode of action of taxodone, the efficacy of taxodone was determined by measuring the release of 260 nm absorbing materials from the selected Candida species as compared to control. The taxodone at the concentration of 400 μg/disc displayed potential antimycotic effect against the tested clinical and pathogenic isolates of Candida species as diameters of zones of inhibitions, which were found in the range of 11 ± 0.0 to 12.6 ± 0.5mm. The MIC and MFC values of taxodone against the tested clinical isolates were found in the range of 250 to 1000 and 500 to 2000μ g/mL, respectively. On the other hand, the MIC and MFC values of positive control (amphotericin B) against the tested Candida isolates were found in the range of 62.5 to 250 and 500 to 2000 μg/mL. On the viable counts of the tested fungal isolates, the taxodone exerted significant antimycotic effect. Elaborative study of partial mode of action conducted onto the release of 260nm materials (DNA and RNA) revealed potential detrimental effect of taxodone on the membrane integrity of the tested pathogens at MIC concentration. With respect to the antimycotic effect of taxodone against pathogenic and clinical isolates of Candida species, it might be confirmed that bioactive compound taxodone present in M. glyptostroboides holds therapeutic value of medicinal significance. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure.

PubMed

Pappas, Harry C; Sylejmani, Rina; Graus, Matthew S; Donabedian, Patrick L; Whitten, David G; Neumann, Aaron K

2016-08-01

Candida species are the cause of many bloodstream infections through contamination of indwelling medical devices. These infections account for a 40% mortality rate, posing a significant risk to immunocompromised patients. Traditional treatments against Candida infections include amphotericin B and various azole treatments. Unfortunately, these treatments are associated with high toxicity, and resistant strains have become more prevalent. As a new frontier, light-activated phenylene ethynylenes have shown promising biocidal activity against Gram-positive and -negative bacterial pathogens, as well as the environmental yeast Saccharomyces cerevisiae In this study, we monitored the viability of Candida species after treatment with a cationic conjugated polymer [poly(p-phenylene ethynylene); PPE] or oligomer ["end-only" oligo(p-phenylene ethynylene); EO-OPE] by flow cytometry in order to explore the antifungal properties of these compounds. The oligomer was found to disrupt Candida albicans yeast membrane integrity independent of light activation, while PPE is able to do so only in the presence of light, allowing for some control as to the manner in which cytotoxic effects are induced. The contrast in killing efficacy between the two compounds is likely related to their size difference and their intrinsic abilities to penetrate the fungal cell wall. Unlike EO-OPE-DABCO (where DABCO is quaternized diazabicyclo[2,2,2]octane), PPE-DABCO displayed a strong propensity to associate with soluble β-glucan, which is expected to inhibit its ability to access and perturb the inner cell membrane of Candida yeast. Furthermore, treatment with PPE-DABCO unmasked Candida albicans β-glucan and increased phagocytosis by Dectin-1-expressing HEK-293 cells. In summary, cationic phenylene ethynylenes show promising biocidal activity against pathogenic Candida yeast cells while also exhibiting immunostimulatory effects. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure

PubMed Central

Pappas, Harry C.; Sylejmani, Rina; Graus, Matthew S.; Donabedian, Patrick L.; Whitten, David G.

2016-01-01

Candida species are the cause of many bloodstream infections through contamination of indwelling medical devices. These infections account for a 40% mortality rate, posing a significant risk to immunocompromised patients. Traditional treatments against Candida infections include amphotericin B and various azole treatments. Unfortunately, these treatments are associated with high toxicity, and resistant strains have become more prevalent. As a new frontier, light-activated phenylene ethynylenes have shown promising biocidal activity against Gram-positive and -negative bacterial pathogens, as well as the environmental yeast Saccharomyces cerevisiae. In this study, we monitored the viability of Candida species after treatment with a cationic conjugated polymer [poly(p-phenylene ethynylene); PPE] or oligomer [“end-only” oligo(p-phenylene ethynylene); EO-OPE] by flow cytometry in order to explore the antifungal properties of these compounds. The oligomer was found to disrupt Candida albicans yeast membrane integrity independent of light activation, while PPE is able to do so only in the presence of light, allowing for some control as to the manner in which cytotoxic effects are induced. The contrast in killing efficacy between the two compounds is likely related to their size difference and their intrinsic abilities to penetrate the fungal cell wall. Unlike EO-OPE-DABCO (where DABCO is quaternized diazabicyclo[2,2,2]octane), PPE-DABCO displayed a strong propensity to associate with soluble β-glucan, which is expected to inhibit its ability to access and perturb the inner cell membrane of Candida yeast. Furthermore, treatment with PPE-DABCO unmasked Candida albicans β-glucan and increased phagocytosis by Dectin-1-expressing HEK-293 cells. In summary, cationic phenylene ethynylenes show promising biocidal activity against pathogenic Candida yeast cells while also exhibiting immunostimulatory effects. PMID:27161628

The effect of ultraviolet radiation on the pathogenesis of Candida albicans in mice

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

Denkins, Y.M.

1991-01-01

This dissertation addresses questions concerning the effects of UV radiation on the pathogenesis of opportunistic fungal pathogens such as Candida albicans. UV radiation decreased the survival of Candida-infected mice; however, no correlation was found between suppression of the delayed type hypersensitivity (DTH) response and the course of lethal infection. This suggested that DTH was not protective against lethal disease with this organism. UV radiation also changed the persistence of the organism in the internal organs. UV-irradiated, infected animals had increased numbers of Candida in their kidneys compared to non-irradiated mice. Sensitization prior to UV irradiation aided clearance of the organismmore » from the kidneys of UV-irradiated mice. These data show that UV radiation suppresses cell-mediated immunity to Candida albicans in mice and increases mortality of Candida-infected mice. Moreover, the data suggest that an increase in environmental UV radiation could increase the severity of pathogenic infections.« less

Proanthocyanidin-rich extracts from cranberry fruit (Vaccinium macrocarpon Ait.) selectively inhibit the growth of human pathogenic fungi Candida spp. and Cryptococcus neoformans.

PubMed

Patel, Kunal D; Scarano, Frank J; Kondo, Miwako; Hurta, Robert A R; Neto, Catherine C

2011-12-28

Cranberry ( Vaccinium macrocarpon ) has been shown in clinical studies to reduce infections caused by Escherichia coli and other bacteria, and proanthocyanidins are believed to play a role. The ability of cranberry to inhibit the growth of opportunistic human fungal pathogens that cause oral, skin, respiratory, and systemic infections has not been well-studied. Fractions from whole cranberry fruit were screened for inhibition of five Candida species and Cryptococcus neoformans , a causative agent of fungal meningitis. Candida glabrata , Candida lusitaniae , Candida krusei , and Cryptococcus neoformans showed significant susceptibility to treatment with cranberry proanthocyanidin fractions in a broth microdilution assay, with minimum inhibitory concentrations as low as 1 μg/mL. MALDI-TOF MS analysis of subfractions detected epicatechin oligomers of up to 12 degrees of polymerization. Those containing larger oligomers caused the strongest inhibition. This study suggests that cranberry has potential as an antifungal agent.

New secondary metabolites from bioactive extracts of the fungus Armillaria tabescens

USDA-ARS?s Scientific Manuscript database

Ethyl acetate extracts of Armillaria tabescens (strain JNB-OZ344) mycelium showed significant fungistatic and bacteristatic activities against several major human pathogens including Candida albicans, Cryptococcus neoformans, Escherichia coli and Mycobacterium intracellulare. Chemical analysis of th...

Diversity and antifungal resistance patterns of prevalent opportunistic pathogenic yeasts colonizing the oral cavities of asymptomatic human immunodeficiency virus-infected individuals, and their relation to CD4+ counts

PubMed Central

Kumar, Deepa Anil; Muralidhar, Sumathi; Banerjee, Uma; Basir, Seemi Farhat; Mathur, Purva; Khan, Luqman Ahmad

2015-01-01

Background: Yeasts are important opportunistic pathogens, in individuals infected with human immunodeficiency virus (HIV). Yeast species inhabiting the oral mucosa of HIV-infected persons can act as source of oral lesions, especially as the individual progresses towards immunocompromised state. Present study was conducted to evaluate the diversity of yeasts in oral cavities of asymptomatic HIV-infected persons and their association with CD4+ cell counts. Materials and Methods: 100 HIV seropositive subjects and 100 healthy controls were screened for oral yeast carriage using standard procedures. Results: Of the 100 HIV-seropositive persons screened, 48 were colonized by different yeasts, either alone or in association with another species. Candida albicans was the most common species (56.90%) while non C. albicans Candida (NCAC) accounted for 39.65%. Among NCAC, Candida tropicalis and Candida krusei were most common. One isolate each of rare opportunistic pathogenic yeasts, Geotrichum candidum and Saccharomyces cereviseae, was recovered. The control group had an oral candidal carriage rate of 23%; C. albicans was the predominant species, followed by Candida glabrata, C. tropicalis and Candida parapsilosis. Antifungal susceptibility testing revealed no resistance in C. albicans, to the commonly used antifungal agents, whereas resistance or dose dependent susceptibility to fluconazole was observed in some of the NCAC species. Conclusion: Oral carriage of opportunistic pathogenic yeasts was greater in HIV-seropositive persons heading towards immunocompromised state, as evidenced by their CD4+ cell count. The predominant yeast isolated in this study (C. albicans), was found to be susceptible to commonly used antifungals. PMID:26392655

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.

Modulation of Morphogenesis in Candida albicans by Various Small Molecules ▿

PubMed Central

Shareck, Julie; Belhumeur, Pierre

2011-01-01

The pathogenic yeast Candida albicans, a member of the mucosal microbiota, is responsible for a large spectrum of infections, ranging from benign thrush and vulvovaginitis in both healthy and immunocompromised individuals to severe, life-threatening infections in immunocompromised patients. A striking feature of C. albicans is its ability to grow as budding yeast and as filamentous forms, including hyphae and pseudohyphae. The yeast-to-hypha transition contributes to the overall virulence of C. albicans and may even constitute a target for the development of antifungal drugs. Indeed, impairing morphogenesis in C. albicans has been shown to be a means to treat candidiasis. Additionally, a large number of small molecules such as farnesol, fatty acids, rapamycin, geldanamycin, histone deacetylase inhibitors, and cell cycle inhibitors have been reported to modulate the yeast-to-hypha transition in C. albicans. In this minireview, we take a look at molecules that modulate morphogenesis in this pathogenic yeast. When possible, we address experimental findings regarding their mechanisms of action and their therapeutic potential. We discuss whether or not modulating morphogenesis constitutes a strategy to treat Candida infections. PMID:21642508

Thailandins A and B, New Polyene Macrolactone Compounds Isolated from Actinokineospora bangkokensis Strain 44EHW(T), Possessing Antifungal Activity against Anthracnose Fungi and Pathogenic Yeasts.

PubMed

Intra, Bungonsiri; Greule, Anja; Bechthold, Andreas; Euanorasetr, Jirayut; Paululat, Thomas; Panbangred, Watanalai

2016-06-29

Two new polyene macrolactone antibiotics, thailandins A, 1, and B, 2, were isolated from the fermentation broth of rhizosphere soil-associated Actinokineospora bangkokensis strain 44EHW(T). The new compounds from this strain were purified using semipreparative HPLC and Sephadex LH-20 gel filtration while following an antifungal activity guided fractionation. Their structures were elucidated through spectroscopic techniques including UV, HR-ESI-MS, and NMR. These compounds demonstrated broad spectrum antifungal activity against fungi causing anthracnose disease (Colletotrichum gloeosporioides DoA d0762, Colletotrichum gloeosporiodes DoA c1060, and Colletotrichum capsici DoA c1511) as well as pathogenic yeasts (Candida albicans MT 2013/1, Candida parasilopsis DKMU 434, and Cryptococcus neoformans MT 2013/2) with minimum inhibitory concentrations ranging between 16 and 32 μg/mL. This is the first report of polyene antibiotics produced by Actinokineospora species as bioactive compounds against anthracnose fungi and pathogenic yeast strains.

The Candida albicans Hwp2p can complement the lack of filamentation of a Saccharomyces cerevisiae flo11 null strain.

PubMed

Younes, Samer S; Khalaf, Roy A

2013-06-01

The opportunistic fungal pathogen Candida albicans is one of the leading agents of life-threatening infections affecting immunocompromised individuals. Many factors make C. albicans a successful pathogen. These include the ability to switch between yeast and invasive hyphal morphologies in addition to an arsenal of cell wall virulence factors such as lipases, proteases, dismutases and adhesins that promote the attachment to the host, a prerequisite for invasive growth. We have previously characterized Hwp2, a C. albicans cell wall protein which we found necessary for proper oxidative stress, biofilm formation and adhesion to host cells. Baker's yeast Saccharomyces cerevisiae also possesses adhesins that promote aggregation and flocculence. Flo11 is one such adhesin that has sequence similarity to Hwp2. Here we determined that transforming an HWP2 cassette can complement the lack of filamentation of an S. cerevisiae flo11 null strain and impart on S. cerevisiae adhesive properties similar to those of a pathogen.

Use of phylogenetical analysis to predict susceptibility of pathogenic Candida spp. to antifungal drugs.

PubMed

Maheux, Andrée F; Sellam, Adnane; Piché, Yves; Boissinot, Maurice; Pelletier, René; Boudreau, Dominique K; Picard, François J; Trépanier, Hélène; Boily, Marie-Josée; Ouellette, Marc; Roy, Paul H; Bergeron, Michel G

2016-12-01

Successful treatment of a Candida infection relies on 1) an accurate identification of the pathogenic fungus and 2) on its susceptibility to antifungal drugs. In the present study we investigated the level of correlation between phylogenetical evolution and susceptibility of pathogenic Candida spp. to antifungal drugs. For this, we compared a phylogenetic tree, assembled with the concatenated sequences (2475-bp) of the ATP2, TEF1, and TUF1 genes from 20 representative Candida species, with published minimal inhibitory concentrations (MIC) of the four principal antifungal drug classes commonly used in the treatment of candidiasis: polyenes, triazoles, nucleoside analogues, and echinocandins. The phylogenetic tree revealed three distinct phylogenetic clusters among Candida species. Species within a given phylogenetic cluster have generally similar susceptibility profiles to antifungal drugs and species within Clusters II and III were less sensitive to antifungal drugs than Cluster I species. These results showed that phylogenetical relationship between clusters and susceptibility to several antifungal drugs could be used to guide therapy when only species identification is available prior to information pertaining to its resistance profile. An extended study comprising a large panel of clinical samples should be conducted to confirm the efficiency of this approach in the treatment of candidiasis. Copyright © 2016. Published by Elsevier B.V.

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.

Rapid and Accurate Molecular Identification of the Emerging Multidrug-Resistant Pathogen Candida auris

PubMed Central

Zhao, Yanan; Lockhart, Shawn R.; Berrio, Indira

2017-01-01

ABSTRACT Candida auris is an emerging multidrug-resistant fungal pathogen causing nosocomial and invasive infections associated with high mortality. C. auris is commonly misidentified as several different yeast species by commercially available phenotypic identification platforms. Thus, there is an urgent need for a reliable diagnostic method. In this paper, we present fast, robust, easy-to-perform and interpret PCR and real-time PCR assays to identify C. auris and related species: Candida duobushaemulonii, Candida haemulonii, and Candida lusitaniae. Targeting rDNA region nucleotide sequences, primers specific for C. auris only or C. auris and related species were designed. A panel of 140 clinical fungal isolates was used in both PCR and real-time PCR assays followed by electrophoresis or melting temperature analysis, respectively. The identification results from the assays were 100% concordant with DNA sequencing results. These molecular assays overcome the deficiencies of existing phenotypic tests to identify C. auris and related species. PMID:28539346

Rapid and Accurate Molecular Identification of the Emerging Multidrug-Resistant Pathogen Candida auris.

PubMed

Kordalewska, Milena; Zhao, Yanan; Lockhart, Shawn R; Chowdhary, Anuradha; Berrio, Indira; Perlin, David S

2017-08-01

Candida auris is an emerging multidrug-resistant fungal pathogen causing nosocomial and invasive infections associated with high mortality. C. auris is commonly misidentified as several different yeast species by commercially available phenotypic identification platforms. Thus, there is an urgent need for a reliable diagnostic method. In this paper, we present fast, robust, easy-to-perform and interpret PCR and real-time PCR assays to identify C. auris and related species: Candida duobushaemulonii , Candida haemulonii , and Candida lusitaniae Targeting rDNA region nucleotide sequences, primers specific for C. auris only or C. auris and related species were designed. A panel of 140 clinical fungal isolates was used in both PCR and real-time PCR assays followed by electrophoresis or melting temperature analysis, respectively. The identification results from the assays were 100% concordant with DNA sequencing results. These molecular assays overcome the deficiencies of existing phenotypic tests to identify C. auris and related species. Copyright © 2017 Kordalewska et al.

Signaling through protein kinases and transcriptional regulators in Candida albicans.

PubMed

Dhillon, Navneet K; Sharma, Sadhna; Khuller, G K

2003-01-01

The human fungal pathogen Candida albicans switches from a budding yeast form to a polarized hyphal form in response to various external signals. This morphogenetic switching has been implicated in the development of pathogenicity. Several signaling pathways that regulate morphogenesis have been identified, including various transcription factors that either activate or repress hypha-specific genes. Two well-characterized pathways include the MAP kinase cascade and cAMP-dependent protein kinase pathway that regulate the transcription factors Cph1p and Efg1p, respectively. cAMP also appears to interplay with other second messengers: Ca2+, inositol tri-phosphates in regulating yeast-hyphal transition. Other, less-characterized pathways include two component histidine kinases, cyclin-dependent kinase pathway, and condition specific pathways such as pH and embedded growth conditions. Nrg1 and Rfg1 function as transcriptional repressors of hyphal genes via recruitment of Tup1 co-repressor complex. Different upstream signals converge into a common downstream output during hyphal switch. The levels of expression of several genes have been shown to be associated with hyphal morphogenesis rather than with a specific hypha-inducing condition. Hyphal development is also linked to the expression of a range of other virulence factors. This review explains the relative contribution of multiple pathways that could be used by Candida albican cells to sense subtle differences in the growth conditions of its native host environment.

Transcriptional Control of Drug Resistance, Virulence and Immune System Evasion in Pathogenic Fungi: A Cross-Species Comparison.

PubMed

Pais, Pedro; Costa, Catarina; Cavalheiro, Mafalda; Romão, Daniela; Teixeira, Miguel C

2016-01-01

Transcription factors are key players in the control of the activation or repression of gene expression programs in response to environmental stimuli. The study of regulatory networks taking place in fungal pathogens is a promising research topic that can help in the fight against these pathogens by targeting specific fungal pathways as a whole, instead of targeting more specific effectors of virulence or drug resistance. This review is focused on the analysis of regulatory networks playing a central role in the referred mechanisms in the human fungal pathogens Aspergillus fumigatus, Cryptococcus neoformans, Candida albicans, Candida glabrata, Candida parapsilosis , and Candida tropicalis . Current knowledge on the activity of the transcription factors characterized in each of these pathogenic fungal species will be addressed. Particular focus is given to their mechanisms of activation, regulatory targets and phenotypic outcome. The review further provides an evaluation on the conservation of transcriptional circuits among different fungal pathogens, highlighting the pathways that translate common or divergent traits among these species in what concerns their drug resistance, virulence and host immune evasion features. It becomes evident that the regulation of transcriptional networks is complex and presents significant variations among different fungal pathogens. Only the oxidative stress regulators Yap1 and Skn7 are conserved among all studied species; while some transcription factors, involved in nutrient homeostasis, pH adaptation, drug resistance and morphological switching are present in several, though not all species. Interestingly, in some cases not very homologous transcription factors display orthologous functions, whereas some homologous proteins have diverged in terms of their function in different species. A few cases of species specific transcription factors are also observed.

Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species.

PubMed

Yücesoy, Mine; Marol, Serhat

2003-10-29

The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37 degrees C. The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar.

Candida infection in oral leukoplakia: an unperceived public health problem.

PubMed

Dilhari, Ayomi; Weerasekera, Manjula M; Siriwardhana, Anusha; Maheshika, Oshanthi; Gunasekara, Chinthika; Karunathilaka, Sunil; Nagahawatte, Ajith; Fernando, Neluka

2016-10-01

The study aimed to determine the proportion, known risk factors and etiology for Candida infection in leukoplakia lesions among patients with oral leukoplakia attending the Oral and Maxillofacial Clinic at a Tertiary Care Hospital in Sri Lanka. Eighty clinically suspected oral leukoplakia patients were included. Two oral swabs each, from leukoplakia patients: one swab from the lesion and the other one from the contralateral unaffected corresponding area (as a control) were collected. Direct microscopy and culture followed by colony count and phenotypic identification were performed to identify pathogenic Candida species. Candida infection was seen in 47% of patients with oral leukoplakia. Candida albicans (94.7%) was the most common Candida species followed by Candida tropicalis (5.3%). Majority of Candida-infected lesions were seen in the buccal mucosa region. Alteration of taste (p = 0.021), having other oral lesions (p = 0.008), angular cheilitis (p = 0.024) and periodontitis (p = 0.041) showed a significant association with Candida-associated leukoplakia. Increasing age showed a significant tendency for Candida infection (p = 0.020). Smoking (p = 0.026) and betel-quid chewing (p = 0.006) were also found to be significantly associated, although alcohol consumption alone did not show a significant association. Oral leukoplakia patients who had all three habits: alcohol consumption, smoking and betel-quid chewing had a significant association with Candida infection (p = 0.004). Patients who had a combination of risk factors: smoking, betel-quid chewing and alcohol consumption were seen to have a significant association with Candida infection. Further betel-quid chewing alone and smoking singly was also significantly associated with Candida infection in oral leukoplakia.

Structure of Protein Geranylgeranyltransferase-I from the Human Pathogen Candida albicans Complexed with a Lipid Substrate

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

Hast, Michael A.; Beese, Lorena S.

2008-11-21

Protein geranylgeranyltransferase-I (GGTase-I) catalyzes the transfer of a 20-carbon isoprenoid lipid to the sulfur of a cysteine residue located near the C terminus of numerous cellular proteins, including members of the Rho superfamily of small GTPases and other essential signal transduction proteins. In humans, GGTase-I and the homologous protein farnesyltransferase (FTase) are targets of anticancer therapeutics because of the role small GTPases play in oncogenesis. Protein prenyltransferases are also essential for many fungal and protozoan pathogens that infect humans, and have therefore become important targets for treating infectious diseases. Candida albicans, a causative agent of systemic fungal infections in immunocompromisedmore » individuals, is one pathogen for which protein prenylation is essential for survival. Here we present the crystal structure of GGTase-I from C. albicans (CaGGTase-I) in complex with its cognate lipid substrate, geranylgeranylpyrophosphate. This structure provides a high-resolution picture of a non-mammalian protein prenyltransferase. There are significant variations between species in critical areas of the active site, including the isoprenoid-binding pocket, as well as the putative product exit groove. These differences indicate the regions where specific protein prenyltransferase inhibitors with antifungal activity can be designed.« less

In vitro antimicrobial activity of Caesalpinia ferrea Martius fruits against oral pathogens.

PubMed

Sampaio, Fábio C; Pereira, Maria do Socorro V; Dias, Celidarque S; Costa, Vicente Carlos O; Conde, Nikeila C O; Buzalaf, Marília A R

2009-07-15

In the Amazon region of Brazil, the fruits of Caesalpinia ferrea Martius (Brazilian ironwood) are widely used as an antimicrobial and healing medicine in many situations including oral infections. This study aimed to evaluate the antimicrobial activity of Caesalpinia ferrea Martius fruit extract against oral pathogens. Polyphenols estimation and spectral analysis ((1)H NMR) of the methanol extract were carried out. The microorganisms Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were tested using the microdilution method for planktonic cells (MIC) and a multispecies biofilm model. Chlorhexidine was used as positive control. Polyphenols in the extract were estimated at 7.3% and (1)H NMR analysis revealed hydroxy phenols and methoxilated compounds. MIC values for Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were 25.0, 40.0, 66.0, 100.0, 66.0 microg/mL, respectively. For the biofilm assay, chlorhexidine and plant extract showed no growth at 10(-4) and 10(-5) microbial dilution, respectively. At 10(-4) and 10(-5) the growth values (mean+/-SD) of the negative controls (DMSO and saline solution) for Streptococcus mutans, Streptococcus sp. and Candida albicans were 8.1+/-0.7, 7.0+/-0.6 and 5.9+/-0.9 x 10(6)CFU, respectively. Caesalpinia ferrea fruit extract can inhibit in vitro growth of oral pathogens in planktonic and biofilm models supporting its use for oral infections.

Silver nanoparticles induced alterations in multiple cellular targets, which are critical for drug susceptibilities and pathogenicity in fungal pathogen (Candida albicans)

PubMed Central

Radhakrishnan, Venkatraman Srinivasan; Reddy Mudiam, Mohana Krishna; Kumar, Manish; Dwivedi, Surya Prakash; Singh, Surinder Pal; Prasad, Tulika

2018-01-01

Purpose A significant increase in the incidence of fungal infections and drug resistance has been observed in the past decades due to limited availability of broad-spectrum antifungal drugs. Nanomedicines have shown significant antimicrobial potential against various drug-resistant microbes. Silver nanoparticles (AgNps) are known for their antimicrobial properties and lower host toxicity; however, for clinical applications, evaluation of their impact at cellular and molecular levels is essential. The present study aims to understand the cellular and molecular mechanisms of AgNp-induced toxicity in a common fungal pathogen, Candida albicans. Methods AgNps were synthesized by chemical reduction method and characterized using UV–visible spectroscopy, X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, energy dispersive X-ray fluorescence, and zeta potential. The anti-Candida activity of AgNps was assessed by broth microdilution and spot assays. Effects of AgNps on cellular and molecular targets were assessed by monitoring the intracellular reactive oxygen species (ROS) production in the absence and presence of natural antioxidant, changes in surface morphology, cellular ultrastructure, membrane microenvironment, membrane fluidity, membrane ergosterol, and fatty acids. Results Spherical AgNps (10–30 nm) showed minimum inhibitory concentration (minimum concentration required to inhibit the growth of 90% of organisms) at 40 μg/mL. Our results demonstrated that AgNps induced dose-dependent intracellular ROS which exerted antifungal effects; however, even scavenging ROS by antioxidant could not offer protection from AgNp mediated killing. Treatment with AgNps altered surface morphology, cellular ultrastructure, membrane microenvironment, membrane fluidity, ergosterol content, and fatty acid composition, especially oleic acid. Conclusion To summarize, AgNps affected multiple cellular targets crucial for drug resistance and pathogenicity in the fungal cells. The study revealed new cellular targets of AgNps which include fatty acids like oleic acid, vital for hyphal morphogenesis (a pathogenic trait of Candida). Yeast to hypha transition being pivotal for virulence and biofilm formation, targeting virulence might emerge as a new paradigm for developing nano silver-based therapy for clinical applications in fungal therapeutics. PMID:29760548

Reclassification of the Candida haemulonii complex as Candida haemulonii (C. haemulonii group I), C. duobushaemulonii sp. nov. (C. haemulonii group II), and C. haemulonii var. vulnera var. nov.: three multiresistant human pathogenic yeasts.

PubMed

Cendejas-Bueno, E; Kolecka, A; Alastruey-Izquierdo, A; Theelen, B; Groenewald, M; Kostrzewa, M; Cuenca-Estrella, M; Gómez-López, A; Boekhout, T

2012-11-01

The Candida haemulonii species complex is currently known as C. haemulonii groups I and II. Here we describe C. haemulonii group II as a new species, Candida duobushaemulonii sp. nov., and C. haemulonii var. vulnera as new a variety of C. haemulonii group I using phenotypic and molecular methods. These taxa and other relatives of C. haemulonii (i.e., Candida auris and Candida pseudohaemulonii) cannot be differentiated by the commercial methods now used for yeast identification. Four isolates (C. haemulonii var. vulnera) differed from the other isolates of C. haemulonii in the sequence of the internal transcribed spacer (ITS) regions of the nuclear rRNA gene operon. The new species and the new variety have a multiresistant antifungal profile, which includes high MICs of amphotericin B (geometric mean MIC, 1.18 mg/liter for C. haemulonii var. vulnera and 2 mg/liter for C. duobushaemulonii sp. nov) and cross-resistance to azole compounds. Identification of these species should be based on molecular methods, such as sequence analysis of ITS regions and matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Plasma membrane organization promotes virulence of the human fungal pathogen Candida albicans

PubMed Central

Douglas, Lois M.; Konopka, James. B.

2017-01-01

Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions as a protective barrier, it also mediates dynamic functions including secretion of virulence factors, cell wall synthesis, invasive hyphal morphogenesis, endocytosis, and nutrient uptake. Consistent with this functional complexity, the plasma membrane is composed of a wide array of lipids and proteins. These components are organized into distinct domains that will be the topic of this review. Some of the plasma membrane domains that will be described are known to act as scaffolds or barriers to diffusion, such as MCC/eisosomes, septins, and sites of contact with the endoplasmic reticulum. Other zones mediate dynamic processes, including secretion, endocytosis, and a special region at hyphal tips that facilitates rapid growth. The highly organized architecture of the plasma membrane facilitates the coordination of diverse functions and promotes the pathogenesis of C. albicans. PMID:26920878

Plasma membrane organization promotes virulence of the human fungal pathogen Candida albicans.

PubMed

Douglas, Lois M; Konopka, James B

2016-03-01

Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions as a protective barrier, it also mediates dynamic functions including secretion of virulence factors, cell wall synthesis, invasive hyphal morphogenesis, endocytosis, and nutrient uptake. Consistent with this functional complexity, the plasma membrane is composed of a wide array of lipids and proteins. These components are organized into distinct domains that will be the topic of this review. Some of the plasma membrane domains that will be described are known to act as scaffolds or barriers to diffusion, such as MCC/eisosomes, septins, and sites of contact with the endoplasmic reticulum. Other zones mediate dynamic processes, including secretion, endocytosis, and a special region at hyphal tips that facilitates rapid growth. The highly organized architecture of the plasma membrane facilitates the coordination of diverse functions and promotes the pathogenesis of C. albicans.

Comparative Phenotypic Analysis of the Major Fungal Pathogens Candida parapsilosis and Candida albicans

PubMed Central

Holland, Linda M.; Schröder, Markus S.; Turner, Siobhán A.; Taff, Heather; Andes, David; Grózer, Zsuzsanna; Gácser, Attila; Ames, Lauren; Haynes, Ken; Higgins, Desmond G.; Butler, Geraldine

2014-01-01

Candida parapsilosis and Candida albicans are human fungal pathogens that belong to the CTG clade in the Saccharomycotina. In contrast to C. albicans, relatively little is known about the virulence properties of C. parapsilosis, a pathogen particularly associated with infections of premature neonates. We describe here the construction of C. parapsilosis strains carrying double allele deletions of 100 transcription factors, protein kinases and species-specific genes. Two independent deletions were constructed for each target gene. Growth in >40 conditions was tested, including carbon source, temperature, and the presence of antifungal drugs. The phenotypes were compared to C. albicans strains with deletions of orthologous transcription factors. We found that many phenotypes are shared between the two species, such as the role of Upc2 as a regulator of azole resistance, and of CAP1 in the oxidative stress response. Others are unique to one species. For example, Cph2 plays a role in the hypoxic response in C. parapsilosis but not in C. albicans. We found extensive divergence between the biofilm regulators of the two species. We identified seven transcription factors and one protein kinase that are required for biofilm development in C. parapsilosis. Only three (Efg1, Bcr1 and Ace2) have similar effects on C. albicans biofilms, whereas Cph2, Czf1, Gzf3 and Ume6 have major roles in C. parapsilosis only. Two transcription factors (Brg1 and Tec1) with well-characterized roles in biofilm formation in C. albicans do not have the same function in C. parapsilosis. We also compared the transcription profile of C. parapsilosis and C. albicans biofilms. Our analysis suggests the processes shared between the two species are predominantly metabolic, and that Cph2 and Bcr1 are major biofilm regulators in C. parapsilosis. PMID:25233198

Candida parapsilosis is a Significant Neonatal Pathogen: A Systematic Review and Meta-Analysis

PubMed Central

Pammi, Mohan; Holland, Linda; Butler, Geraldine; Gacser, Attila; Bliss, Joseph M.

2013-01-01

Background Candida is the third most common cause of late-onset neonatal sepsis in infants born at < 1500 g. C. parapsilosis infections are increasingly reported in preterm neonates in association with indwelling catheters. Methods We systematically reviewed neonatal literature and synthesized data pertaining to percentage of C. parapsilosis infections and mortality by meta-analyses. We also reviewed risk factors, virulence determinants, antimicrobial susceptibility patterns and outlined clinical management strategies. Results C. parapsilosis infections comprised 33.47 % [95% CI, 30.02, 37.31] of all neonatal Candida infections. C. parapsilosis rates were similar in studies performed before the year 2000, 33.53 % [95% CI, 30.06, 37.40] (28 studies), to those after 2000, 27.00% [95% CI, 8.25, 88.37] (8 studies). The mortality due to neonatal Candida parapsilosis infections was 10.02% [95% CI, 7.66, 13.12]. Geographical variations in C. parapsilosis infections included a low incidence in Europe and higher incidence in North America and Australia. Biofilm formation was a significant virulence determinant and predominant risk factors for C. parapsilosis infections were prematurity, prior colonization and catheterization. Amphotericin B remains the antifungal drug of choice and combination therapy with caspofungin or other echinocandins may be considered in resistant cases. Conclusion C. parapsilosis is a significant neonatal pathogen, comprises a third of all Candida infections and is associated with 10% mortality. Availability of tools for genetic manipulation of this organism will identify virulence determinants and organism characteristics that may explain predilection for preterm neonates. Strategies to prevent horizontal transmission in the neonatal unit are paramount in decreasing infection rates. PMID:23340551

The Endoplasmic Reticulum-Mitochondrion Tether ERMES Orchestrates Fungal Immune Evasion, Illuminating Inflammasome Responses to Hyphal Signals

PubMed Central

Tucey, Timothy M.; Verma-Gaur, Jiyoti; Nguyen, Julie; Hewitt, Victoria L.; Lo, Tricia L.; Shingu-Vazquez, Miguel; Robertson, Avril A. B.; Hill, James R.; Pettolino, Filomena A.; Beddoe, Travis; Cooper, Matthew A.; Naderer, Thomas

2016-01-01

ABSTRACT The pathogenic yeast Candida albicans escapes macrophages by triggering NLRP3 inflammasome-dependent host cell death (pyroptosis). Pyroptosis is inflammatory and must be tightly regulated by host and microbe, but the mechanism is incompletely defined. We characterized the C. albicans endoplasmic reticulum (ER)-mitochondrion tether ERMES and show that the ERMES mmm1 mutant is severely crippled in killing macrophages despite hyphal formation and normal phagocytosis and survival. To understand dynamic inflammasome responses to Candida with high spatiotemporal resolution, we established live-cell imaging for parallel detection of inflammasome activation and pyroptosis at the single-cell level. This showed that the inflammasome response to mmm1 mutant hyphae is delayed by 10 h, after which an exacerbated activation occurs. The NLRP3 inhibitor MCC950 inhibited inflammasome activation and pyroptosis by C. albicans, including exacerbated inflammasome activation by the mmm1 mutant. At the cell biology level, inactivation of ERMES led to a rapid collapse of mitochondrial tubular morphology, slow growth and hyphal elongation at host temperature, and reduced exposed 1,3-β-glucan in hyphal populations. Our data suggest that inflammasome activation by C. albicans requires a signal threshold dependent on hyphal elongation and cell wall remodeling, which could fine-tune the response relative to the level of danger posed by C. albicans. The phenotypes of the ERMES mutant and the lack of conservation in animals suggest that ERMES is a promising antifungal drug target. Our data further indicate that NLRP3 inhibition by MCC950 could modulate C. albicans-induced inflammation. IMPORTANCE The yeast Candida albicans causes human infections that have mortality rates approaching 50%. The key to developing improved therapeutics is to understand the host-pathogen interface. A critical interaction is that with macrophages: intracellular Candida triggers the NLRP3/caspase-1 inflammasome for escape through lytic host cell death, but this also activates antifungal responses. To better understand how the inflammasome response to Candida is fine-tuned, we established live-cell imaging of inflammasome activation at single-cell resolution, coupled with analysis of the fungal ERMES complex, a mitochondrial regulator that lacks human homologs. We show that ERMES mediates Candida escape via inflammasome-dependent processes, and our data suggest that inflammasome activation is controlled by the level of hyphal growth and exposure of cell wall components as a proxy for severity of danger. Our study provides the most detailed dynamic analysis of inflammasome responses to a fungal pathogen so far and establishes promising pathogen- and host-derived therapeutic strategies. PMID:27303738

The Endoplasmic Reticulum-Mitochondrion Tether ERMES Orchestrates Fungal Immune Evasion, Illuminating Inflammasome Responses to Hyphal Signals.

PubMed

Tucey, Timothy M; Verma-Gaur, Jiyoti; Nguyen, Julie; Hewitt, Victoria L; Lo, Tricia L; Shingu-Vazquez, Miguel; Robertson, Avril A B; Hill, James R; Pettolino, Filomena A; Beddoe, Travis; Cooper, Matthew A; Naderer, Thomas; Traven, Ana

2016-01-01

The pathogenic yeast Candida albicans escapes macrophages by triggering NLRP3 inflammasome-dependent host cell death (pyroptosis). Pyroptosis is inflammatory and must be tightly regulated by host and microbe, but the mechanism is incompletely defined. We characterized the C. albicans endoplasmic reticulum (ER)-mitochondrion tether ERMES and show that the ERMES mmm1 mutant is severely crippled in killing macrophages despite hyphal formation and normal phagocytosis and survival. To understand dynamic inflammasome responses to Candida with high spatiotemporal resolution, we established live-cell imaging for parallel detection of inflammasome activation and pyroptosis at the single-cell level. This showed that the inflammasome response to mmm1 mutant hyphae is delayed by 10 h, after which an exacerbated activation occurs. The NLRP3 inhibitor MCC950 inhibited inflammasome activation and pyroptosis by C. albicans, including exacerbated inflammasome activation by the mmm1 mutant. At the cell biology level, inactivation of ERMES led to a rapid collapse of mitochondrial tubular morphology, slow growth and hyphal elongation at host temperature, and reduced exposed 1,3-β-glucan in hyphal populations. Our data suggest that inflammasome activation by C. albicans requires a signal threshold dependent on hyphal elongation and cell wall remodeling, which could fine-tune the response relative to the level of danger posed by C. albicans. The phenotypes of the ERMES mutant and the lack of conservation in animals suggest that ERMES is a promising antifungal drug target. Our data further indicate that NLRP3 inhibition by MCC950 could modulate C. albicans-induced inflammation. IMPORTANCE The yeast Candida albicans causes human infections that have mortality rates approaching 50%. The key to developing improved therapeutics is to understand the host-pathogen interface. A critical interaction is that with macrophages: intracellular Candida triggers the NLRP3/caspase-1 inflammasome for escape through lytic host cell death, but this also activates antifungal responses. To better understand how the inflammasome response to Candida is fine-tuned, we established live-cell imaging of inflammasome activation at single-cell resolution, coupled with analysis of the fungal ERMES complex, a mitochondrial regulator that lacks human homologs. We show that ERMES mediates Candida escape via inflammasome-dependent processes, and our data suggest that inflammasome activation is controlled by the level of hyphal growth and exposure of cell wall components as a proxy for severity of danger. Our study provides the most detailed dynamic analysis of inflammasome responses to a fungal pathogen so far and establishes promising pathogen- and host-derived therapeutic strategies.

Therapeutic Application of Synbiotics, a Fusion of Probiotics and Prebiotics, and Biogenics as a New Concept for Oral Candida Infections: A Mini Review

PubMed Central

Ohshima, Tomoko; Kojima, Yukako; Seneviratne, Chaminda J.; Maeda, Nobuko

2016-01-01

Candida is a major human fungal pathogen causing infectious conditions predominantly in the elderly and immunocompromised hosts. Although Candida resides as a member of the oral indigenous microbiota in symbiosis, some circumstances may cause microbial imbalance leading to dysbiosis and resultant oral candidiasis. Therefore, oral microbial symbiosis that suppresses the overgrowth of Candida is important for a healthy oral ecosystem. In this regard, probiotics, prebiotics, and synbiotics can be considered a potential therapeutic and preventive strategy against oral candidiasis. Prebiotics have a direct effect on microbial growth as they stimulate the growth of beneficial bacteria and suppress the growth of pathogens. Probiotics render a local protective effect against pathogens and a systemic indirect effect on immunological amelioration. Synbiotics are fusion products of prebiotics and probiotics. This mini review discusses the potential use and associated limitations of probiotics, prebiotics, and synbiotics for the prevention and treatment of oral candidiasis. We will also introduce biogenics, a recent concept derived from the work on probiotics. Biogenics advocates the use of beneficial bioactive substances produced by probiotic bacteria, whose activities are independent from the viability of probiotic bacteria in human bodies. PMID:26834728

Typing and virulence factors of food-borne Candida spp. isolates.

PubMed

Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina

2018-08-20

Food-borne yeasts, excluding yeasts used as starter cultures, are commonly considered as food spoilage microorganisms. However, the incidence of non-C. albicans Candida (NCAC) infections has increased considerably over the past two decades. Although 15 Candida species are frequently identified as pathogens, a threat to human from food-borne Candida is poorly recognized. In the present study food-borne NCAC were characterized for the virulence factors, known to be associated with yeast pathogenicity. All food-borne strains in planktonic forms and 89% in biofilm structures represented biotypes established for C. albicans, and 61% demonstrated hemolytic activity. 56-94% of food-borne isolates formed biofilms on glass and biomaterials at a level comparable to clinical C. albicans. Nine out of eighteen tested food-borne NCAC strains (C. krusei, C. lusitaniae, C. famata, C. colliculosa, C. parapsilosis, C. tropicalis) showed similarity to clinical C. albicans in terms of their biotypes and the tested virulence factors, allocating them in a group of risk of potential pathogens. However, their capacity to grow at 37 °C seems to be the preliminary criterion in the study of potential virulence of food-borne yeasts. Copyright © 2018 Elsevier B.V. All rights reserved.

New staining methods for yeast like fungi under special consideration of human pathogenic fungi

NASA Astrophysics Data System (ADS)

Paulitsch-Fuchs, Astrid; Treiber, Fritz; Grasser, Erik; Buzina, Walter; Rosker, Christian

2010-11-01

A new method for in-cellular staining of yeast like fungi with Oregon Green and SYTOX Green is presented enabling their detection as well as the observation of cellular details via confocal laser scanning microscopy. Fluorochromes play an important role in many scientific disciplines including medicine, cell biology and botany. For the visualisation of fungal cell walls Calcofluor White is the flourochrome of choice. The necessity of an UV laser for its excitation makes it unpracticable for daily use. Safranin O, DAPI, 2NBDG, Ethidium Bromide and Acridin-orange are commonly used stains for nuclei in fugal microscopy. The attention was given to the possibility of using the differences in staining patterns to distinguish certain pathogenic yeast species e.g. Candida albicans and Candida krusei. Our results show that high quality microscopy of yeast like organisms can readily be achieved by the use of two suitable fluorochromes.

Host-pathogen interactions between the human innate immune system and Candida albicans—understanding and modeling defense and evasion strategies

PubMed Central

Dühring, Sybille; Germerodt, Sebastian; Skerka, Christine; Zipfel, Peter F.; Dandekar, Thomas; Schuster, Stefan

2015-01-01

The diploid, polymorphic yeast Candida albicans is one of the most important human pathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within the human host for a long time. However, alterations in the host environment can render C. albicans virulent. In this review, we describe the immunological cross-talk between C. albicans and the human innate immune system. We give an overview in form of pairs of human defense strategies including immunological mechanisms as well as general stressors such as nutrient limitation, pH, fever etc. and the corresponding fungal response and evasion mechanisms. Furthermore, Computational Systems Biology approaches to model and investigate these complex interactions are highlighted with a special focus on game-theoretical methods and agent-based models. An outlook on interesting questions to be tackled by Systems Biology regarding entangled defense and evasion mechanisms is given. PMID:26175718

Moonlight-like proteins of the cell wall protect sessile cells of Candida from oxidative stress.

PubMed

Serrano-Fujarte, Isela; López-Romero, Everardo; Cuéllar-Cruz, Mayra

2016-01-01

Biofilms of Candida species are associated with high morbidity and hospital mortality. Candida forms biofilms by adhering to human host epithelium through cell wall proteins (CWP) and simultaneously neutralizing the reactive oxygen species (ROS) produced during the respiratory burst by phagocytic cells. The purpose of this paper is to identify the CWP of Candida albicans, Candida glabrata, Candida krusei and Candida parapsilosis expressed after exposure to different concentrations of H2O2 using a proteomic approach. CWP obtained from sessile cells, both treated and untreated with the oxidizing agent, were resolved by one and two-dimensional (2D-PAGE) gels and identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Some of these proteins were identified and found to correspond to moonlighting CWP such as: (i) glycolytic enzymes, (ii) heat shock, (iii) OSR proteins, (iv) general metabolic enzymes and (v) highly conserved proteins, which are up- or down-regulated in the presence or absence of ROS. We also found that the expression of these CWP is different for each Candida species. Moreover, RT-PCR assays allowed us to demonstrate that transcription of the gene coding for Eno1, one of the moonlight-like CWP identified in response to the oxidant agent, is differentially regulated. To our knowledge this is the first demonstration that, in response to oxidative stress, each species of Candida, differentially regulates the expression of moonlighting CWP, which may protect the organism from the ROS generated during phagocytosis. Presumptively, these proteins allow the pathogen to adhere and form a biofilm, and eventually cause invasive candidiasis in the human host. We propose that, in addition to the antioxidant mechanisms present in Candida, the moonlighting CWP also confer protection to these pathogens from oxidative stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isolation of Candida dubliniensis for the first time in Cali, Colombia, and its identification with phenotyping methods.

PubMed

Alvarez, María Inés; Suárez, Blanca Lynne; Caicedo, Luz Dary

2009-01-01

Candida dubliniensis is an emerging pathogenic yeast isolated mainly from the oral cavity of HIV-infected patients. The close phenotypic and genotypic relationship between C. albicans and C. dubliniensis has led to incorrectly identifying isolates of C. dubliniensis as C. albicans. The oral cavities of 107 diabetic patients were studied in Cali, Colombia, and 72 colonies of Candida, with shades of green on CHROMagar Candida culture media, were obtained. Various phenotypic tests were carried out, which included germ tube formation and production of chlamydospores on corn meal Agar. Additionally, growth studies were carried out at 42 degrees C and 45 degrees C and on Sabouraud agar with 6.5%, sodium chloride. Identification of C. dubliniensis with these tests was confirmed with API 20C Aux. We identified 65 and 7 colonies of C. albicans and C. dubliniensis, respectively. This is the first time that C. dubliniensis is identified with phenotypic methods in Colombia.

Candida parapsilosis Protects Premature Intestinal Epithelial Cells from Invasion and Damage by Candida albicans

PubMed Central

Gonia, Sara; Archambault, Linda; Shevik, Margaret; Altendahl, Marie; Fellows, Emily; Bliss, Joseph M.; Wheeler, Robert T.; Gale, Cheryl A.

2017-01-01

Candida is a leading cause of late-onset sepsis in premature infants and is thought to invade the host via immature or damaged epithelial barriers. We previously showed that the hyphal form of Candida albicans invades and causes damage to premature intestinal epithelial cells (pIECs), whereas the non-hyphal Candida parapsilosis, also a fungal pathogen of neonates, has less invasion and damage abilities. In this study, we investigated the potential for C. parapsilosis to modulate pathogenic interactions of C. albicans with the premature intestine. While a mixed infection with two fungal pathogens may be expected to result in additive or synergistic damage to pIECs, we instead found that C. parapsilosis was able to protect pIECs from invasion and damage by C. albicans. C. albicans-induced pIEC damage was reduced to a similar extent by multiple different C. parapsilosis strains, but strains differed in their ability to inhibit C. albicans invasion of pIECs, with the inhibitory activity correlating with their adhesiveness for C. albicans and epithelial cells. C. parapsilosis cell-free culture fractions were also able to significantly reduce C. albicans adhesion and damage to pIECs. Furthermore, coadministration of C. parapsilosis cell-free fractions with C. albicans was associated with decreased infection and mortality in zebrafish. These results indicate that C. parapsilosis is able to reduce invasion, damage, and virulence functions of C. albicans. Additionally, the results with cellular and cell-free fractions of yeast cultures suggest that inhibition of pathogenic interactions between C. albicans and host cells by C. parapsilosis occurs via secreted molecules as well as by physical contact with the C. parapsilosis cell surface. We propose that non-invasive commensals can be used to inhibit virulence features of pathogens and deserve further study as a non-pharmacological strategy to protect the fragile epithelial barriers of premature infants. PMID:28382297

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.

New secondary metabolites from bioactive extracts of the fungus Armillaria tabescens

Treesearch

H. M. T.Bandara Herath; Melissa Jacob; A. Alpus Wilson; Hamed K. Abbas; N.P. Dhammika Nanayakkara Nanayakkara

2012-01-01

Ethyl acetate extracts of Armillaria tabescens (strain JNB-OZ344) showed significant fungistatic and bacteristatic activities against several major human pathogens including Candida albicans, Cryptococcus neoformans, Escherichia coli and Mycobacterium intracellulare. Chemical analysis of these extracts led to the isolation and identification of four new compounds,...

Oxidative Stress Responses in the Human Fungal Pathogen, Candida albicans

PubMed Central

da Silva Dantas, Alessandra; Day, Alison; Ikeh, Mélanie; Kos, Iaroslava; Achan, Beatrice; Quinn, Janet

2015-01-01

Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen. PMID:25723552

Fungicidal efficacy of various honeys against fluconazole-resistant Candida species isolated from HIV+ patients with candidiasis.

PubMed

Shokri, H; Sharifzadeh, A

2017-06-01

Honey is well known to possess a broad spectrum of activity against medically important organisms. The purpose of this study was to assess the antifungal activity of different honeys against 40 fluconazole (FLU) resistant Candida species, including Candida albicans (C. albicans), Candida glabrata, Candida krusei and Candida tropicalis. Three honey samples were collected from northern (Mazandaran, A), southern (Hormozgan, B) and central (Lorestan, C) regions of Iran. A microdilution technique based on the CLSI, M27-A2 protocol was employed to compare the susceptibility of honeys "A", "B" and "C" against different pathogenic Candida isolates. The results showed that different Candida isolates were resistant to FLU, ranging from 64μg/mL to 512μg/mL. All of the honeys tested had antifungal activities against FLU-resistant Candida species, ranging from 20% to 56.25% (v/v) and 25% to 56.25% (v/v) for minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs), respectively. Honey "A" (MIC: 31.59%, v/v) showed higher anti-Candida activity than honey "B" (MIC: 35.99%, v/v) and honey "C" (MIC: 39.2%, v/v). No statistically significant differences were observed among the mean MIC values of the honey samples (P>0.05). The order of overall susceptibility of Candida species to honey samples were; C. krusei>C. glabrata>C. tropicalis>C. albicans (P>0.05). In addition, the mean MICs of Candida strains isolated from the nail, vagina and oral cavity were 33.68%, 36.44% and 39.89%, respectively, and were not significantly different (P>0.05). Overall, varying susceptibilities to the anti-Candida properties of different honeys were observed with four FLU-resistant species of Candida. Further research is needed to assess the efficacy of honey as an inhibitor of candidal growth in clinical trials. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cloth-covered chiropractic treatment tables as a source of allergens and pathogenic microbes.

PubMed

Evans, Marion W; Campbell, Alan; Husbands, Chris; Breshears, Jennell; Ndetan, Harrison; Rupert, Ronald

2008-03-01

Vinyl chiropractic tables have been found to harbor pathogenic bacteria, but wiping with a simple disinfection agent can significantly reduce the risk of bacteria. The aim of this study was to assess the presence of microbes and other allergens or pathogens on cloth chiropractic tables. Cloth-covered tables in a chiropractic college teaching clinic were selected. Samples were taken from the facial piece and hand rests with RODAC plates containing nutrient agar, followed by confirmatory testing when indicated. Numerous microbacteria strains were found, including Staphylococcus aureus and Propionibacterium. Allergen-producing molds, including Candida, were also found. Cloth tables were shown to contain pathogenic microbacteria and allergens. The chiropractic profession should establish an infection control protocol relevant to treatment tables and discard use of cloth-covered treatment tables in this process.

Hyphal Growth in Human Fungal Pathogens and Its Role in Virulence

PubMed Central

Brand, Alexandra

2012-01-01

Most of the fungal species that infect humans can grow in more than one morphological form but only a subset of pathogens produce filamentous hyphae during the infection process. This subset is phylogenetically unrelated and includes the commonly carried yeasts, Candida albicans, C. dubliniensis, and Malassezia spp., and the acquired pathogens, Aspergillus fumigatus and dermatophytes such as Trichophyton rubrum and T. mentagrophytes. The primary function of hypha formation in these opportunistic pathogens is to invade the substrate they are adhered to, whether biotic or abiotic, but other functions include the directional translocation between host environments, consolidation of the colony, nutrient acquisition and the formation of 3-dimensional matrices. To support these functions, polarised hyphal growth is co-regulated with other factors that are essential for normal hypha function in vivo. PMID:22121367

D-Cateslytin: a new antifungal agent for the treatment of oral Candida albicans associated infections.

PubMed

Dartevelle, Pauline; Ehlinger, Claire; Zaet, Abdurraouf; Boehler, Christian; Rabineau, Morgane; Westermann, Benoit; Strub, Jean-Marc; Cianferani, Sarah; Haïkel, Youssef; Metz-Boutigue, Marie-Hélène; Marban, Céline

2018-06-18

The excessive use of antifungal agents, compounded by the shortage of new drugs being introduced into the market, is causing the accumulation of multi-resistance phenotypes in many fungal strains. Consequently, new alternative molecules to conventional antifungal agents are urgently needed to prevent the emergence of fungal resistance. In this context, Cateslytin (Ctl), a natural peptide derived from the processing of Chromogranin A, has already been described as an effective antimicrobial agent against several pathogens including Candida albicans. In the present study, we compared the antimicrobial activity of two conformations of Ctl, L-Ctl and D-Ctl against Candida albicans. Our results show that both D-Ctl and L-Ctl were potent and safe antifungal agents. However, in contrast to L-Ctl, D-Ctl was not degraded by proteases secreted by Candida albicans and was also stable in saliva. Using video microscopy, we also demonstrated that D-Ctl can rapidly enter C. albicans, but is unable to spread within a yeast colony unless from a mother cell to a daughter cell during cellular division. Besides, we revealed that the antifungal activity of D-Ctl could be synergized by voriconazole, an antifungal of reference in the treatment of Candida albicans related infections. In conclusion, D-Ctl can be considered as an effective, safe and stable antifungal and could be used alone or in a combination therapy with voriconazole to treat Candida albicans related diseases including oral candidosis.

Oral Candidal Carriage in Subjects with Pure Vegetarian and Mixed Dietary Habits

PubMed Central

Patil, Shankargouda; Rao, Roopa S; Sanketh, D.S.; Sarode, Sachin; Sarode, Gargi

2017-01-01

Introduction Candida albicans being a part of the normal oral microbial flora is one of the most commonly isolated species from the oral cavity. Recent studies have shown a steady rise in the number of non C. albicans species, which are relatively resistant to common antifungal agents and are being recognized as potential pathogens. It is vital to ascertain the predisposing factors leading to such a shift in the oral candidal flora. Aim To estimate the prevalence of candidal species among vegetarians and non-vegetarians. Materials and Methods Clinical data including age, gender, and diet preference of 238 participants were noted. Participants with a history of systemic disorders, oral prosthesis, salivary gland disorders and habits such as smoking, alcoholism, and tobacco usage were excluded from the study. The participants were asked to gargle a 10 ml solution of phosphate buffered saline for one minute before depositing the same in a sterile container. The samples were cultured using Hicrome agar media. Data analysis was carried out using Statistical Package for Social Sciences (SPSS software) version 10.5 and differences between individual groups were tested by Chi-square test. Results Among 238 samples, 127 (53.3%) samples were positive for Candida. The candidal prevalence in vegetarians (68.5%) was higher than non-vegetarians (40.7%). C. albicans was the most common species to be isolated in both vegetarians (35.1%) and non-vegetarians (39.2%). Candida glabrata and Candida tropicalis showed a higher prevalence in vegetarians (30.5% and 10.1%, respectively) in comparison to non-vegetarians (8.4% and 2.3%, respectively). Candida krusei was isolated only from vegetarians (4.6%). Conclusion Results indicate that diet plays a major role in oral candidal prevalence and species specificity which in turn may predispose the vegetarians toward these pathogenic organisms. PMID:28893036

Oral Candidal Carriage in Subjects with Pure Vegetarian and Mixed Dietary Habits.

PubMed

Patil, Shankargouda; Rao, Roopa S; Raj, A Thirumal; Sanketh, D S; Sarode, Sachin; Sarode, Gargi

2017-07-01

Candida albicans being a part of the normal oral microbial flora is one of the most commonly isolated species from the oral cavity. Recent studies have shown a steady rise in the number of non C. albicans species, which are relatively resistant to common antifungal agents and are being recognized as potential pathogens. It is vital to ascertain the predisposing factors leading to such a shift in the oral candidal flora. To estimate the prevalence of candidal species among vegetarians and non-vegetarians. Clinical data including age, gender, and diet preference of 238 participants were noted. Participants with a history of systemic disorders, oral prosthesis, salivary gland disorders and habits such as smoking, alcoholism, and tobacco usage were excluded from the study. The participants were asked to gargle a 10 ml solution of phosphate buffered saline for one minute before depositing the same in a sterile container. The samples were cultured using Hicrome agar media. Data analysis was carried out using Statistical Package for Social Sciences (SPSS software) version 10.5 and differences between individual groups were tested by Chi-square test. Among 238 samples, 127 (53.3%) samples were positive for Candida . The candidal prevalence in vegetarians (68.5%) was higher than non-vegetarians (40.7%). C. albicans was the most common species to be isolated in both vegetarians (35.1%) and non-vegetarians (39.2%). Candida glabrata and Candida tropicalis showed a higher prevalence in vegetarians (30.5% and 10.1%, respectively) in comparison to non-vegetarians (8.4% and 2.3%, respectively). Candida krusei was isolated only from vegetarians (4.6%). Results indicate that diet plays a major role in oral candidal prevalence and species specificity which in turn may predispose the vegetarians toward these pathogenic organisms.

Distribution of Candida albican genotype and Candida species is associated with the severity of vulvovagianl candidiasis.

PubMed

Zeng, Jun; Zong, Li-li; Mao, Ting; Huang, Yu-xing; Xu, Zheng-mei

2011-10-01

To investigate the distribution of pathogenic C.albican genotype and Candida species in association with the severity of vulvovaginal candidiasis (VVC). Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) of the internal transcribed spacer analysis was employed to identify the Candida species isolated from the vaginal secretions of 198 patients with acute VVC. SSCP and GeneScan analyses of microsatellite locus I polymorphism were used to determine the genotypes of the clinical isolates of C. albican associated with VVC. All the patients were scored for clinical signs and symptoms to evaluate the severity of VVC. A total of 198 Candida strains were isolated from VVC patients, including 140 (70.7%) C. albicans strains and 58 (29.3%) non-albicans strains. In the 95 patients with severe VVC and 103 with mild-moderate VVC, C.albican was detected in 62.1% and 76.6% of the patients, respectively (P=0.011). Thirty-eight microsatellite locus I genotypes were detected in 140 unrelated C. albican strains, among which the dominant genotypes 30-45 (44 strians, 31.43%) and 32-46 (23 strains, 16.43%) were the most common, followed by genotypes 30-46 (4 strains, 2.86%) and 32-47 (9 strains, 6.42%). The overall frequencies of the 4 genotypes were significantly higher in severe VVC than in mild-moderate VVC cases (77.9% vs 42.0%, P<0.001). C. albicans remains the most common pathogenic Candia species in patients with VVC, but the non-alibcans species seem more likely to cause severe VVC. The dominant genotypes of C. albicans with a tropism for the vagina are correlated to the severity of VVC.

Otomastoiditis caused by Candida auris: Case report and literature review.

PubMed

Choi, Hyoung Il; An, Jin; Hwang, Jae Joon; Moon, Soo-Youn; Son, Jun Seong

2017-08-01

Fungal otomastoiditis is a rare disease, but can be fatal for immunocompromised patients. Recently, there have been increasing cases of otologic infection caused by Candida auris. Candida auris can be easily misdiagnosed for other species and treatment is difficult due to multidrug resistance. Clinician should be aware of this rare pathogen, and it should be treated with appropriate antifungal agent with surgical debridement. © 2017 Blackwell Verlag GmbH.

Identification of cytolytic vaginosis versus vulvovaginal candidiasis.

PubMed

Hu, Zhengqiang; Zhou, Wei; Mu, Liyuan; Kuang, Linghan; Su, Min; Jiang, Yongmei

2015-04-01

This study aimed to observe the morphological characteristic of vaginal discharge in patients with cytolytic vaginosis (CV) under the microscope and to identify it in patients with CV and in patients with vulvovaginal candidiasis (VVC). A total of 108 subjects including 21 healthy women, 33 patients with CV, and 54 patients with VVC were enrolled in the present morphological study. Vaginal discharge was collected and made into smear. The morphological characteristics of these vaginal smears with Gram staining were observed under the microscope. The smears were assessed for the quantity of lactobacilli, epithelial cell morphology, and the absence or presence of Candida species, Trichomonas vaginalis, and clue sells. First, the age, the level of education, and especially the status of pregnancy of patients with CV were significantly different from those of the patients with VVC. Second, the morphological characteristics of patients with CV consisted of overgrowth of lactobacilli, the presence of naked nuclei and fragments of the epithelial cells, a paucity of leukocytes, and the absence of Candida species and other pathogens. However, the morphological characteristic of patients with VVC consisted of the presence or absence of lactobacilli and the presence of normal epithelial cells, candidal spores, blastospores, hyphae, or other pathogens such as T. vaginalis and Gardnerella vaginalis. Both CV and VVC can be identified based on the quantity of lactobacilli, the morphology of the epithelial cells, and the absence or presence of Candida species and other pathogens, and the misdiagnosis of CV as VVC can be avoided.

Fungal spondylodiscitis in a patient recovered from H7N9 virus infection: a case study and a literature review of the differences between Candida and Aspergillus spondylodiscitis * #

PubMed Central

Yu, Lie-dao; Feng, Zhi-yun; Wang, Xuan-wei; Ling, Zhi-heng; Lin, Xiang-jin

2016-01-01

To report a rare case of fungal spondylodiscitis in a patient recovered from H7N9 virus infection and perform a literature review of the different characteristics of Candida and Aspergillus spondylodiscitis, we reviewed cases of spondylodiscitis caused by Candida and Aspergillus species. Data, including patients’ information, pathogenic species, treatment strategy, outcomes, and relapses, were collected and summarized. The characteristics of Candida and Aspergillus spondylodiscitis were compared to see if any differences in clinical features, management, or consequences could be detected. The subject of the case study was first misdiagnosed as having a vertebral tumor, and then, following open biopsy, was diagnosed as having fungal spondylodiscitis. The patient made a good recovery following radical debridement. Seventy-seven additional cases of Candida spondylodiscitis and 94 cases of Aspergillus spondylodiscitis were identified in the literature. Patients with Candida spondylodiscitis tended to have a better outcome than patients with Aspergillus spondylodiscitis (cure rate 92.3% vs. 70.2%). Candida was found more frequently (47.8%) than Aspergillus (26.7%) in blood cultures, while neurological deficits were observed more often in patients with Aspergillus spondylodiscitis (43.6% vs. 25.6%). Candida spinal infections were more often treated by radical debridement (60.5% vs. 39.6%). Patients with Candida spondylodiscitis have better outcomes, which may be associated with prompt recognition, radical surgical debridement, and azoles therapy. A good outcome can be expected in fungal spondylodiscitis with appropriate operations and anti-fungal drugs. PMID:27819134

Molecular epidemiology, phylogeny and evolution of Candida albicans.

PubMed

McManus, Brenda A; Coleman, David C

2014-01-01

A small number of Candida species form part of the normal microbial flora of mucosal surfaces in humans and may give rise to opportunistic infections when host defences are impaired. Candida albicans is by far the most prevalent commensal and pathogenic Candida species. Several different molecular typing approaches including multilocus sequence typing, multilocus microsatellite typing and DNA fingerprinting using C. albicans-specific repetitive sequence-containing DNA probes have yielded a wealth of information regarding the epidemiology and population structure of this species. Such studies revealed that the C. albicans population structure consists of multiple major and minor clades, some of which exhibit geographical or phenotypic enrichment and that C. albicans reproduction is predominantly clonal. Despite this, losses of heterozygosity by recombination, the existence of a parasexual cycle, toleration of a wide range of aneuploidies and the recent description of viable haploid strains have all demonstrated the extensive plasticity of the C. albicans genome. Recombination and gross chromosomal rearrangements are more common under stressful environmental conditions, and have played a significant role in the evolution of this opportunistic pathogen. Surprisingly, Candida dubliniensis, the closest relative of C. albicans exhibits more karyotype variability than C. albicans, but is significantly less adaptable to unfavourable environments. This disparity most likely reflects the evolutionary processes that occurred during or soon after the divergence of both species from their common ancestor. Whilst C. dubliniensis underwent significant gene loss and pseudogenisation, C. albicans expanded gene families considered to be important in virulence. It is likely that technological developments in whole genome sequencing and data analysis in coming years will facilitate its routine use for population structure, epidemiological investigations, and phylogenetic analyses of Candida species. These are likely to reveal more minor C. albicans clades and to enhance our understanding of the population biology of this versatile organism. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

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.

Quantification of oral palatine Langerhans cells in HIV/AIDS associated oral Kaposi sarcoma with and without oral candidiasis.

PubMed

Jivan, Vibha; Meer, Shabnum

2016-01-01

Langerhans cells (LCs) are effective antigen-presenting cells that function as "custodians" of mucosa, modifying the immune system to pathogen entry, and tolerance to self-antigen and commensal microbes. A reduction in number of LCs in human immunodeficiency virus (HIV)-positive individuals may predispose to local mucosal infections. To quantitatively determine the number of oral mucosal LCs in HIV/acquired immunodeficiency syndrome HIV/acquired immunodeficiency syndrome (AIDS) associated oral Kaposi sarcoma (KS) with/without oral candidiasis (OC) and to define in situ interrelationships between the cells, OC, and HIV infection. Thirty-two periodic acid-Schiff. (PAS) stained histologic sections of palatal HIV/AIDS associated KS with intact oral epithelium were examined for Candida and divided into two groups: . (1) KS coinfected with Candida and. (2) KS noninfected with Candida. Sections were immunohistochemically stained with CD1a. The standard length of surface epithelium was measured and number of positively stained LCs counted per unit length. Control cases included non-Candida infected palatal mucosa overlying pleomorphic adenoma. (PA) and oral mucosa infected with Candida in otherwise healthy individuals. LC number per unit length of surface epithelium was statistically significantly greatest in uninfected PA mucosa and lowest in KS coinfected with Candida (P = 0.0001). A statistically significant difference was also noted between uninfected PA mucosa and non-Candida infected KS (P = 0.0014), in KS coinfected with Candida and non-infected KS (P = 0.0035), between OC and PA (P = 0.0001), and OC and KS coinfected with Candida (P = 0.0247). LC numbers are significantly reduced in oral tissues of HIV/AIDS infected patients by Candida infection when compared to oral tissues without.

Isolation of Candida Species from Gastroesophageal Lesions among Pediatrics in Isfahan, Iran: Identification and Antifungal Susceptibility Testing of Clinical Isolates by E-test

PubMed Central

Salehi, Fatemeh; Esmaeili, Mehran; Mohammadi, Rasoul

2017-01-01

Background: Candida species can become opportunistic pathogens causing local or systemic invasive infections. Gastroesophageal candidiasis may depend on the Candida colonization and local damage of the mucosal barrier. Risk factors are gastric acid suppression, diabetes mellitus, chronic debilitating states such as carcinomas, and the use of systemic antibiotics and corticosteroids. The aim of this study is collection and molecular identification of Candida species from gastroesophageal lesions among pediatrics in Isfahan, and determination of minimum inhibitory concentration (MIC) ranges for clinical isolates. Materials and Methods: A total of 200 patients underwent endoscopy (130 specimens from gastritis and 70 samples from esophagitis) were included in this study between April 2015 and November 2015. All specimens were subcultured on sabouraud dextrose agar, and genomic DNA of all strains was extracted using boiling method. Polymerase chain reaction and DNA sequencing of the ITS1-5.8SrDNA-ITS2 region were used for the identification of all Candida strains. MIC ranges were determined for itraconazole (ITC), amphotericin B (AmB), and fluconazole (FLU) by E-test. Results: Twenty of 200 suspected patients (10%) were positive by direct microscopy and culture. Candida albicans was the most common species (60%) followed by Candida glabrata (30%), Candida parapsilosis (5%), and Candida kefyr (5%). MIC ranges were determined for FLU (0.125–8 μg/mL), ITC (0.008–0.75 μg/mL), and AmB (0.008–0.75 μg/mL), respectively. Conclusion: Every colonization of Candida species should be considered as a potentially factor of mucocutaneous candidiasis and should be treated with antifungal drugs. PMID:28904931

Development of a CRISPR-Cas9 System for Efficient Genome Editing of Candida lusitaniae.

PubMed

Norton, Emily L; Sherwood, Racquel K; Bennett, Richard J

2017-01-01

Candida lusitaniae is a member of the Candida clade that includes a diverse group of fungal species relevant to both human health and biotechnology. This species exhibits a full sexual cycle to undergo interconversion between haploid and diploid forms. C. lusitaniae is also an emerging opportunistic pathogen that can cause serious bloodstream infections in the clinic and yet has often proven to be refractory to facile genetic manipulations. In this work, we develop a clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated gene 9 (Cas9) system to enable genome editing of C. lusitaniae . We demonstrate that expression of CRISPR-Cas9 components under species-specific promoters is necessary for efficient gene targeting and can be successfully applied to multiple genes in both haploid and diploid isolates. Gene deletion efficiencies with CRISPR-Cas9 were further enhanced in C. lusitaniae strains lacking the established nonhomologous end joining (NHEJ) factors Ku70 and DNA ligase 4. These results indicate that NHEJ plays an important role in directing the repair of DNA double-strand breaks (DSBs) in C. lusitaniae and that removal of this pathway increases integration of gene deletion templates by homologous recombination. The described approaches significantly enhance the ability to perform genetic studies in, and promote understanding of, this emerging human pathogen and model sexual species. IMPORTANCE The ability to perform efficient genome editing is a key development for detailed mechanistic studies of a species. Candida lusitaniae is an important member of the Candida clade and is relevant both as an emerging human pathogen and as a model for understanding mechanisms of sexual reproduction. We highlight the development of a CRISPR-Cas9 system for efficient genome manipulation in C. lusitaniae and demonstrate the importance of species-specific promoters for expression of CRISPR components. We also demonstrate that the NHEJ pathway contributes to non-template-mediated repair of DNA DSBs and that removal of this pathway enhances efficiencies of gene targeting by CRISPR-Cas9. These results therefore establish important genetic tools for further exploration of C. lusitaniae biology.

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

Candida albicans and C. tropicalis Isolates from the Expired Breathes of Captive Dolphins and Their Environments in an Aquarium

PubMed Central

Takahashi, Hideo; Ueda, Keiichi; Itano, Eiko Nakagawa; Yanagisawa, Makio; Murata, Yoshiteru; Murata, Michiko; Yaguchi, Takashi; Murakami, Masaru; Kamei, Katsuhiko; Inomata, Tomo; Miyahara, Hirokazu; Sano, Ayako; Uchida, Senzo

2010-01-01

Genotypes of Candida spp. isolated from exhalation of 20 dolphins, 11 water samples from captive pools, and 24 oral cavities of staff members in an aquarium using a combination of multiple drug resistance 1 gene (MDR1) and the internal transcribed spacer (ITS) 1 5.8s-ITS 2 regions of ribosomal RNA gene (ITS rDNA) sequences were studied. The holding ratios of the dolphins, captive pools, and staff members were 70, 90, and 29%, respectively. Isolated pathogenic yeast species common to the dolphins and environments were Candida albicans and C. tropicalis. Identical genotypes in both Candida spp. based on the combination of MDR1 and ITSrDNA were found in some dolphins, between a dolphin and a staff, among dolphins and environments, and among environments. The results indicated the diffusion and exchange of pathogenic yeasts at the aquarium among dolphins and environments. The isolates at the aquarium showed higher rates of resistance to azole antifungals compared to reference isolates. PMID:21234394

Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

PubMed Central

Yücesoy, Mine; Marol, Serhat

2003-01-01

Background The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. Methods A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37°C. Results The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. Conclusions It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar. PMID:14613587

Potential Antifungal Targets against a Candida Biofilm Based on an Enzyme in the Arachidonic Acid Cascade—A Review

PubMed Central

Liu, Xinning; Wang, Decai; Yu, Cuixiang; Li, Tao; Liu, Jianqiao; Sun, Shujuan

2016-01-01

Candida is an important opportunistic fungal pathogen, especially in biofilm associated infections. The formation of a Candida biofilm can decrease Candida sensitivity to antifungal drugs and cause drug resistance. Although many effective antifungal drugs are available, their applications are limited due to their high toxicity and cost. Seeking new antifungal agents that are effective against biofilm-associated infection is an urgent need. Many research efforts are underway, and some progress has been made in this field. It has been shown that the arachidonic acid cascade plays an important role in fungal morphogenesis and pathogenicity. Notably, prostaglandin E2 (PGE2) can promote the formation of a Candida biofilm. Recently, the inhibition of PGE2 has received much attention. Studies have shown that cyclooxygenase (COX) inhibitors, such as aspirin, ibuprofen, and indomethacin, combined with fluconazole can significantly reduce Candida adhesion and biofilm development and increase fluconazole susceptibility; the MIC of fluconazole can be decrease from 64 to 2 μg/ml when used in combination with ibuprofen. In addition, in vivo studies have also confirmed the antifungal activities of these inhibitors. In this article, we mainly review the relationship between PGE2 and Candida biofilm, summarize the antifungal activities of COX inhibitors and analyze the possible antifungal activity of microsomal prostaglandin E synthase-1 (MPGES-1) inhibitors; additionally, other factors that influence PGE2 production are also discussed. Hopefully this review can disclose potential antifungal targets based on the arachidonic acid cascade and provide a prevailing strategy to alleviate Candida albicans biofilm formation. PMID:27999568

Effects of nanosecond pulsed electric fields (nsPEFs) on the human fungal pathogen Candida albicans: an in vitro study

NASA Astrophysics Data System (ADS)

Guo, Jinsong; Dang, Jie; Wang, Kaile; Zhang, Jue; Fang, Jing

2018-05-01

Candida albicans is the leading human fungal pathogen that causes many life-threatening infections. Notably, the current clinical trial data indicate that Candida species shows the emerging resistance to anti-fungal drugs. The aim of this study was to evaluate the antifungal effects of nanosecond pulsed electric fields (nsPEFs) as a novel drug-free strategy in vitro. In this study, we investigated the inactivation and permeabilization effects of C. albicans under different nsPEFs exposure conditions (100 pulses, 100 ns in duration, intensities of 20, 40 kV cm‑1). Cell death was studied by annexin-V and propidium iodide staining. The changes of intracellular Ca2+ concentration after nsPEFs treatment were observed using Fluo-4 AM. Results show that C. albicans cells and biofilms were both obviously inhibited and destroyed after nsPEFs treatment. Furthermore, C. albicans cells were significantly permeabilized after nsPEFs treatment. Additionally, nsPEFs exposure led to a large amount of DNA and protein leakage. Importantly, nsPEFs induced a field strength-dependent apoptosis in C. albicans cells. Further experiments revealed that Ca2+ involved in nsPEFs induced C. albicans apoptosis. In conclusion, this proof-of-concept study provides a potential alternative drug-free strategy for killing pathogenic Candida species.

Ultraviolet Microscopy of Candida albicans

PubMed Central

Balish, Edward; Svihla, George

1966-01-01

Balish, Edward (Argonne National Laboratory, Argonne, Ill.), and George Svihla. Ultraviolet microscopy of Candida albicans. J. Bacteriol. 92:1812–1820. 1966.—Yeast and mycelial strains of Candida albicans were grown in medium supplemented with sulfur amino acids in an effort to determine factors that control the morphology and pathogenicity of the organism. Ultraviolet microscopy revealed a greater concentration of S-adenosylmethionine in the vacuoles of the mycelial phase than in those of yeast phases. Supplementation with amino acids greatly increased the concentration of S-adenosylmethionine in the mycelial phase, and made these cells more sensitive to the lytic action of snail gut enzymes than two yeast phase strains. This indicates a difference in cell wall structure that may be related to the pathogenicity of the mycelial phase. Images PMID:5958110

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.

Prioritizing and modelling of putative drug target proteins of Candida albicans by systems biology approach.

PubMed

Ismail, Tariq; Fatima, Nighat; Muhammad, Syed Aun; Zaidi, Syed Saoud; Rehman, Nisar; Hussain, Izhar; Tariq, Najam Us Sahr; Amirzada, Imran; Mannan, Abdul

2018-01-01

Candida albicans (Candida albicans) is one of the major sources of nosocomial infections in humans which may prove fatal in 30% of cases. The hospital acquired infection is very difficult to treat affectively due to the presence of drug resistant pathogenic strains, therefore there is a need to find alternative drug targets to cure this infection. In silico and computational level frame work was used to prioritize and establish antifungal drug targets of Candida albicans. The identification of putative drug targets was based on acquiring 5090 completely annotated genes of Candida albicans from available databases which were categorized into essential and non-essential genes. The result indicated that 9% of proteins were essential and could become potential candidates for intervention which might result in pathogen eradication. We studied cluster of orthologs and the subtractive genomic analysis of these essential proteins against human genome was made as a reference to minimize the side effects. It was seen that 14% of Candida albicans proteins were evolutionary related to the human proteins while 86% are non-human homologs. In the next step of compatible drug target selections, the non-human homologs were sequentially compared to the human microbiome data to minimize the potential effects against gut flora which accumulated to 38% of the essential genome. The sub-cellular localization of these candidate proteins in fungal cellular systems indicated that 80% of them are cytoplasmic, 10% are mitochondrial and the remaining 10% are associated with the cell wall. The role of these non-human and non-gut flora putative target proteins in Candida albicans biological pathways was studied. Due to their integrated and critical role in Candida albicans replication cycle, four proteins were selected for molecular modeling. For drug designing and development, four high quality and reliable protein models with more than 70% sequence identity were constructed. These proteins are used for the docking studies of the known and new ligands (unpublished data). Our study will be an effective framework for drug target identifications of pathogenic microbial strains and development of new therapies against the infections they cause.

How long do nosocomial pathogens persist on inanimate surfaces? A systematic review.

PubMed

Kramer, Axel; Schwebke, Ingeborg; Kampf, Günter

2006-08-16

Inanimate surfaces have often been described as the source for outbreaks of nosocomial infections. The aim of this review is to summarize data on the persistence of different nosocomial pathogens on inanimate surfaces. The literature was systematically reviewed in MedLine without language restrictions. In addition, cited articles in a report were assessed and standard textbooks on the topic were reviewed. All reports with experimental evidence on the duration of persistence of a nosocomial pathogen on any type of surface were included. Most gram-positive bacteria, such as Enterococcus spp. (including VRE), Staphylococcus aureus (including MRSA), or Streptococcus pyogenes, survive for months on dry surfaces. Many gram-negative species, such as Acinetobacter spp., Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Serratia marcescens, or Shigella spp., can also survive for months. A few others, such as Bordetella pertussis, Haemophilus influenzae, Proteus vulgaris, or Vibrio cholerae, however, persist only for days. Mycobacteria, including Mycobacterium tuberculosis, and spore-forming bacteria, including Clostridium difficile, can also survive for months on surfaces. Candida albicans as the most important nosocomial fungal pathogen can survive up to 4 months on surfaces. Persistence of other yeasts, such as Torulopsis glabrata, was described to be similar (5 months) or shorter (Candida parapsilosis, 14 days). Most viruses from the respiratory tract, such as corona, coxsackie, influenza, SARS or rhino virus, can persist on surfaces for a few days. Viruses from the gastrointestinal tract, such as astrovirus, HAV, polio- or rota virus, persist for approximately 2 months. Blood-borne viruses, such as HBV or HIV, can persist for more than one week. Herpes viruses, such as CMV or HSV type 1 and 2, have been shown to persist from only a few hours up to 7 days. The most common nosocomial pathogens may well survive or persist on surfaces for months and can thereby be a continuous source of transmission if no regular preventive surface disinfection is performed.

Cloth-covered chiropractic treatment tables as a source of allergens and pathogenic microbes☆

PubMed Central

Evans, Marion W.; Campbell, Alan; Husbands, Chris; Breshears, Jennell; Ndetan, Harrison; Rupert, Ronald

2008-01-01

Abstract Objective Vinyl chiropractic tables have been found to harbor pathogenic bacteria, but wiping with a simple disinfection agent can significantly reduce the risk of bacteria. The aim of this study was to assess the presence of microbes and other allergens or pathogens on cloth chiropractic tables. Methods Cloth-covered tables in a chiropractic college teaching clinic were selected. Samples were taken from the facial piece and hand rests with RODAC plates containing nutrient agar, followed by confirmatory testing when indicated. Results Numerous microbacteria strains were found, including Staphylococcus aureus and Propionibacterium. Allergen-producing molds, including Candida, were also found. Conclusion Cloth tables were shown to contain pathogenic microbacteria and allergens. The chiropractic profession should establish an infection control protocol relevant to treatment tables and discard use of cloth-covered treatment tables in this process. PMID:19674718

Yeast microbiota of natural cavities of manatees (Trichechus inunguis and Trichechus manatus) in Brazil and its relevance for animal health and management in captivity.

PubMed

Sidrim, José Júlio Costa; Carvalho, Vitor Luz; Castelo-Branco, Débora de Souza Collares Maia; Brilhante, Raimunda Sâmia Nogueira; Bandeira, Tereza de Jesus Pinheiro Gomes; Cordeiro, Rossana de Aguiar; Guedes, Gláucia Morgana de Melo; Barbosa, Giovanna Riello; Lazzarini, Stella Maris; Oliveira, Daniella Carvalho Ribeiro; de Meirelles, Ana Carolina Oliveira; Attademo, Fernanda Löffler Niemeyer; Freire, Augusto Carlos da Bôaviagem; Moreira, José Luciano Bezerra; Monteiro, André Jalles; Rocha, Marcos Fábio Gadelha

2015-10-01

The aim of this study was to characterize the yeast microbiota of natural cavities of manatees kept in captivity in Brazil. Sterile swabs from the oral cavity, nostrils, genital opening, and rectum of 50 Trichechus inunguis and 26 Trichechus manatus were collected. The samples were plated on Sabouraud agar with chloramphenicol and incubated at 25 °C for 5 days. The yeasts isolated were phenotypically identified by biochemical and micromorphological tests. Overall, 141 strains were isolated, of which 112 were from T. inunguis (Candida albicans, Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, Candida guilliermondii, Candida pelliculosa, Candida tropicalis, Candida glabrata, Candida famata, Candida krusei, Candida norvegensis, Candida ciferri, Trichosporon sp., Rhodotorula sp., Cryptococcus laurentii) and 29 were from T. manatus (C. albicans, C. tropicalis, C. famata, C. guilliermondii, C. krusei, Rhodotorula sp., Rhodotorula mucilaginosa, Rhodotorula minuta, Trichosporon sp.). This was the first systematic study to investigate the importance of yeasts as components of the microbiota of sirenians, demonstrating the presence of potentially pathogenic species, which highlights the importance of maintaining adequate artificial conditions for the health of captive manatees.

Candida Biofilms: Development, Architecture, and Resistance

PubMed Central

CHANDRA, JYOTSNA; MUKHERJEE, PRANAB K.

2015-01-01

Intravascular device–related infections are often associated with biofilms (microbial communities encased within a polysaccharide-rich extracellular matrix) formed by pathogens on the surfaces of these devices. Candida species are the most common fungi isolated from catheter-, denture-, and voice prosthesis–associated infections and also are commonly isolated from contact lens–related infections (e.g., fungal keratitis). These biofilms exhibit decreased susceptibility to most antimicrobial agents, which contributes to the persistence of infection. Recent technological advances have facilitated the development of novel approaches to investigate the formation of biofilms and identify specific markers for biofilms. These studies have provided extensive knowledge of the effect of different variables, including growth time, nutrients, and physiological conditions, on biofilm formation, morphology, and architecture. In this article, we will focus on fungal biofilms (mainly Candida biofilms) and provide an update on the development, architecture, and resistance mechanisms of biofilms. PMID:26350306

Candidemia in the intensive care unit: A 12-year retrospective cohort study in Reunion Island.

PubMed

Hoarau, G; Picot, S; Lemant, J; Peytral, J; Poubeau, P; Zunic, P; Mohr, C; Coueffe, X; Gerardin, P; Antok, E

2018-05-09

We aimed to describe the epidemiology of Candida bloodstream infection in an intensive care unit (ICU) in Reunion Island. We performed a retrospective cohort study and evaluated 63 candidemia episodes, which occurred between January 2004 and December 2015 in the ICU of a University Hospital in St-Pierre. The incidence rate of candidemia in the ICU was estimated at 7.6%. Candida albicans was the most common yeast pathogen species recovered (54%), followed by Candida glabrata (17%), Candida tropicalis (12%) and Candida parapsilosis (10%). Between 2012 and 2015, we also observed a modification of antifungal use. The epidemiology of candidemia in Reunion Island is characterized by the predominance of Candida albicans and by the relative importance of Candida tropicalis. This pattern corresponds to a model of epidemiological transition between the one usually observed in tropical areas and the one observed in temperate countries. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

[Enzymatic activity, slime production and antifungal agent sensitivity of Candida sp].

PubMed

Silva, Jaqueline Otero; Ferreira, Joseane Cristina; Candido, Regina Célia

2007-01-01

Abilith of Candida spp to secrete extracellular enzymes and slime has been associated as pathogenicity factors. Out of a total of 37 strains of Candida sp, 100% were proteinase producers, 83.8% were phospholipase producers, 64.9% were slime producers and 100% were sensitive to fluconazole and itraconazole. Seventeen typings (enzymes/slime) were found. This methodology presented a good discrimination rate (D=0.93) and could be used for phenotypic characterization of yeasts.

Usefulness of the Non-conventional Caenorhabditis elegans Model to Assess Candida Virulence.

PubMed

Ortega-Riveros, Marcelo; De-la-Pinta, Iker; Marcos-Arias, Cristina; Ezpeleta, Guillermo; Quindós, Guillermo; Eraso, Elena

2017-10-01

Invasive candidiasis is caused mainly by Candida albicans, but other Candida species have increasing etiologies. These species show different virulence and susceptibility levels to antifungal drugs. The aims of this study were to evaluate the usefulness of the non-conventional model Caenorhabditis elegans to assess the in vivo virulence of seven different Candida species and to compare the virulence in vivo with the in vitro production of proteinases and phospholipases, hemolytic activity and biofilm development capacity. One culture collection strain of each of seven Candida species (C. albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida metapsilosis, Candida orthopsilosis and Candida parapsilosis) was studied. A double mutant C. elegans AU37 strain (glp-4;sek-1) was infected with Candida by ingestion, and the analysis of nematode survival was performed in liquid medium every 24 h until 120 h. Candida establishes a persistent lethal infection in the C. elegans intestinal tract. C. albicans and C. krusei were the most pathogenic species, whereas C. dubliniensis infection showed the lowest mortality. C. albicans was the only species with phospholipase activity, was the greatest producer of aspartyl proteinase and had a higher hemolytic activity. C. albicans and C. krusei caused higher mortality than the rest of the Candida species studied in the C. elegans model of candidiasis.

Candida profiles and antifungal resistance evolution over a decade in Lebanon.

PubMed

Araj, George Farah; Asmar, Rima George; Avedissian, Aline Zakaria

2015-09-27

Infection with and antifungal resistance of Candida species have been on the rise globally. Relevant data on these pathogens are relatively few in our region, including Lebanon, thus warranting this study. This retrospective study of Candida spp. profiles and their in vitro antifungal susceptibility was based on analysis requests for 186 Candida non-albicans and 61 C. albicans during three periods (2005-2007, 2009-2011, and 2012-2014) over the span of the last 10 years at the American University of Beirut Medical Center (AUBMC), a major tertiary care center in Lebanon. Identification of Candida was done using the API 20C AUX system, and the E-test was used to determine the minimum inhibitory concentrations (MICs) of antifungal agents. Among the 1,300-1,500 Candida isolates recovered yearly, C. albicans rates decreased from 86% in 2005 to around 60% in 2014. Simultaneously, the non-albicans rates increased from 14% in 2005 to around 40% in 2014, revealing 11 species, the most frequent of which were C. tropicalis, C. glabrata, and C. parapsilosis. All these demonstrated high resistance (35%-79%) against itraconazole, but remained uniformly susceptible (100%) to amphotericin B. Though C. albicans and the other species maintained high susceptibility against fluconazole and voriconazole, their MIC90 showed an elevated trend over time, and C. glabrata had the highest resistance rates. The observed rise in resistance among Candida spp. in Lebanon mandates the need for close surveillance and monitoring of antifungal drug resistance for both epidemiologic and treatment purposes.

Rapid identification of fungal pathogens in BacT/ALERT, BACTEC, and BBL MGIT media using polymerase chain reaction and DNA sequencing of the internal transcribed spacer regions.

PubMed

Pryce, Todd M; Palladino, Silvano; Price, Diane M; Gardam, Dianne J; Campbell, Peter B; Christiansen, Keryn J; Murray, Ronan J

2006-04-01

We report a direct polymerase chain reaction/sequence (d-PCRS)-based method for the rapid identification of clinically significant fungi from 5 different types of commercial broth enrichment media inoculated with clinical specimens. Media including BacT/ALERT FA (BioMérieux, Marcy l'Etoile, France) (n = 87), BACTEC Plus Aerobic/F (Becton Dickinson, Microbiology Systems, Sparks, MD) (n = 16), BACTEC Peds Plus/F (Becton Dickinson) (n = 15), BACTEC Lytic/10 Anaerobic/F (Becton Dickinson) (n = 11) bottles, and BBL MGIT (Becton Dickinson) (n = 11) were inoculated with specimens from 138 patients. A universal DNA extraction method was used combining a novel pretreatment step to remove PCR inhibitors with a column-based DNA extraction kit. Target sequences in the noncoding internal transcribed spacer regions of the rRNA gene were amplified by PCR and sequenced using a rapid (24 h) automated capillary electrophoresis system. Using sequence alignment software, fungi were identified by sequence similarity with sequences derived from isolates identified by upper-level reference laboratories or isolates defined as ex-type strains. We identified Candida albicans (n = 14), Candida parapsilosis (n = 8), Candida glabrata (n = 7), Candida krusei (n = 2), Scedosporium prolificans (n = 4), and 1 each of Candida orthopsilosis, Candida dubliniensis, Candida kefyr, Candida tropicalis, Candida guilliermondii, Saccharomyces cerevisiae, Cryptococcus neoformans, Aspergillus fumigatus, Histoplasma capsulatum, and Malassezia pachydermatis by d-PCRS analysis. All d-PCRS identifications from positive broths were in agreement with the final species identification of the isolates grown from subculture. Earlier identification of fungi using d-PCRS may facilitate prompt and more appropriate antifungal therapy.

Proteome analysis of the Albugo candida–Brassica juncea pathosystem reveals that the timing of the expression of defence-related genes is a crucial determinant of pathogenesis

PubMed Central

Kaur, Parwinder; Jost, Ricarda; Sivasithamparam, Krishnapillai; Barbetti, Martin John

2011-01-01

White rust, caused by Albugo candida, is a serious pathogen of Brassica juncea (Indian mustard) and poses a potential hazard to the presently developing canola-quality B. juncea industry worldwide. A comparative proteomic study was undertaken to explore the molecular mechanisms that underlie the defence responses of Brassica juncea to white rust disease caused by the biotrophic oomycete Albugo candida. Nineteen proteins showed reproducible differences in abundance between a susceptible (RH 819) and a resistant variety (CBJ 001) of B. juncea following inoculation with A. candida. The identities of all 19 proteins were successfully established through Q-TOF MS/MS. Five of these proteins were only detected in the resistant variety and showed significant differences in their abundance at various times following pathogen inoculation in comparison to mock-inoculated plants. Among these was a thaumatin-like protein (PR-5), a protein not previously associated with the resistance of B. juncea towards A. candida. One protein, peptidyl-prolyl cis/trans isomerase (PPIase) isoform CYP20-3, was only detected in the susceptible variety and increased in abundance in response to the pathogen. PPIases have recently been discovered to play an important role in pathogenesis by suppressing the host cell's immune response. For a subset of seven proteins examined in more detail, an increase in transcript abundance always preceded their induction at the proteome level. These findings are discussed within the context of the A. candida–Brassica juncea pathosystem, especially in relation to host resistance to this pathogen. PMID:21193577

Disarming Fungal Pathogens: Bacillus safensis Inhibits Virulence Factor Production and Biofilm Formation by Cryptococcus neoformans and Candida albicans

PubMed Central

2017-01-01

ABSTRACT Bacteria interact with each other in nature and often compete for limited nutrient and space resources. However, it is largely unknown whether and how bacteria also interact with human fungal pathogens naturally found in the environment. Here, we identified a soil bacterium, Bacillus safensis, which potently blocked several key Cryptococcus neoformans virulence factors, including formation of the antioxidant pigment melanin and production of the antiphagocytic polysaccharide capsule. The bacterium also inhibited de novo cryptococcal biofilm formation but had only modest inhibitory effects on already formed biofilms or planktonic cell growth. The inhibition of fungal melanization was dependent on direct cell contact and live bacteria. B. safensis also had anti-virulence factor activity against another major human-associated fungal pathogen, Candida albicans. Specifically, dual-species interaction studies revealed that the bacterium strongly inhibited C. albicans filamentation and biofilm formation. In particular, B. safensis physically attached to and degraded candidal filaments. Through genetic and phenotypic analyses, we demonstrated that bacterial chitinase activity against fungal cell wall chitin is a factor contributing to the antipathogen effect of B. safensis. PMID:28974618

The Wor1-like protein Fgp1 regulates pathogenicity, toxin synthesis and reproduction in the phytopathogenic fungus Fusarium graminearum

USDA-ARS?s Scientific Manuscript database

WOR1 is a gene for a conserved fungal regulatory protein controlling the dimorphic switch and pathogenicity in Candida albicans and its ortholog in the plant pathogen Fusarium oxysporum, called SGE1, is also required for pathogenicity and expression of plant effector proteins. F. graminearum, an imp...

The significance of Candida in the human respiratory tract: our evolving understanding.

PubMed

Pendleton, Kathryn M; Huffnagle, Gary B; Dickson, Robert P

2017-04-01

Candida is an opportunistic pathogen and the most commonly isolated fungal genus in humans. Though Candida is often detected in respiratory specimens from humans with and without lung disease, its significance remains undetermined. While historically considered a commensal organism with low virulence potential, the status of Candida as an innocent bystander has recently been called into question by both clinical observations and animal experimentation. We here review what is currently known and yet to be determined about the clinical, microbiological and pathophysiological significance of the detection of Candida spp. in the human respiratory tract. Published by Oxford University Press on behalf of FEMS 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

[THE CHARACTERISTICS OF MORPHOLOGY OF BIOFILM OF PERIODONTIUM UNDER INFLAMMATORY DISEASES OF GUMS (CHRONIC CATARRHAL GINGIVITIS, CHRONIC PERIODONTITIS, CANDIDA-ASSOCIATED PERIODONTITIS) ACCORDING RESULTS OF ELECTRONIC MICROSCOPY].

PubMed

Ippolitov, E V; Didenko, L V; Tzarev, V N

2015-12-01

The study was carried out to analyze morphology of biofilm of periodontium and to develop electronic microscopic criteria of differentiated diagnostic of inflammatory diseases of gums. The scanning electronic microscopy was applied to analyze samples of bioflm of periodont from 70 patients. Including ten patients with every nosologic form of groups with chronic catarrhal periodontitis. of light, mean and severe degree, chronic catarrhal gingivitis, Candida-associated paroperiodontitis and 20 healthy persons with intact periodontium. The analysis was implemented using dual-beam scanning electronic microscope Quanta 200 3D (FEI company, USA) and walk-through electronic micJEM 100B (JEOL, Japan). To detect marker DNA of periodont pathogenic bacteria in analyzed samples the kit of reagentsfor polymerase chain reaction "MultiDent-5" ("GenLab", Russia). The scanning electronic microscopy in combination with transmission electronic microscopy and polymerase chain reaction permits analyzing structure, composition and degree of development of biofilm of periodontium and to apply differentiated diagnostic of different nosologic forms of inflammatory diseases of periodontium, including light form of chronic periodontitis and gingivitis. The electronic microscopical indications of diseases ofperiodontium of inflammatory character are established: catarrhal gingivitis, (coccal morphological alternate), chronic periodontitis (bacillary morphological alternate), Candida-associated periodontitis (Candida morphological alternate of biofilm ofperiodontium).

Asarones from Acorus calamus in combination with azoles and amphotericin B: a novel synergistic combination to compete against human pathogenic Candida species in vitro.

PubMed

Kumar, S Nishanth; Aravind, S R; Sreelekha, T T; Jacob, Jubi; Kumar, B S Dileep

2015-04-01

The increase in drug resistance to current antifungal drugs brings enormous challenges to the management of Candida infection. Therefore, there is a continuous need for the discovery of new antimicrobial agents that are effective against Candida infections especially from natural source especially from medical plants. The present investigation describes the synergistic anticandidal activity of two asarones (∞ and β) purified from Acorus calamus in combination with three clinically used antifungal drugs (fluconazole, clotrimazole, and amphotericin B). The synergistic anticandidal activities of asarones and drugs were assessed using the checkerboard microdilution and time-kill assays. The results of the present study showed that the combined effects of asarones and drugs principally recorded substantial synergistic activity (fractional inhibitory concentration index (FICI) <0.5). Time-kill study by combination of the minimal inhibitory concentration (MIC) of asarones and drugs (1:1) recorded that the growth of the Candida species was significantly arrested between 0 and 2 h and almost completely attenuated between 2 and 6 h of treatment. These findings have potential implications in adjourning the development of resistance as the anticandidal activity is achieved with lower concentrations of asarones and drugs. The combination of asarones and drugs also significantly inhibit the biofilm formation by Candida species, and this would also help to fight against drug resistance because biofilms formed by Candida species are ubiquitous in nature and are characterized by their recalcitrance toward antimicrobial treatment. The in vitro synergistic activity of asarones and drugs against pathogenic Candida species is reported here for the first time.

Candida lusitaniae causing fatal meningitis.

PubMed Central

Sarma, P. S.; Durairaj, P.; Padhye, A. A.

1993-01-01

Fatal meningitis due to Candida lusitaniae in a 35 year old previously healthy man is described. C. lusitaniae is an opportunistic fungal pathogen reported infrequently in the English literature. This is the third case report of meningitis and the first fatal infection in an adult from Central India due to C. lusitaniae known to the authors. PMID:8290437

Enhancement of antimycotic activity of amphotericin B by targeting the oxidative stress response of Candida and Cryptococcus with natural dihydroxybenzaldehydes

USDA-ARS?s Scientific Manuscript database

Many yeast pathogens of humans have become resistant to currently available drugs. Certain types of compounds can increase efficacy of antimycotic drugs through a process termed chemosensitization. Chemosensitizing efficacy was determined in Candida albicans, C. krusei, C. tropicalis and Cryptococcu...

Hyperspectral fluorescence microscopy detects autofluorescent factors that can be exploited as a diagnostic method for Candida species differentiation

NASA Astrophysics Data System (ADS)

Graus, Matthew S.; Neumann, Aaron K.; Timlin, Jerilyn A.

2017-01-01

Fungi in the Candida genus are the most common fungal pathogens. They not only cause high morbidity and mortality but can also cost billions of dollars in healthcare. To alleviate this burden, early and accurate identification of Candida species is necessary. However, standard identification procedures can take days and have a large false negative error. The method described in this study takes advantage of hyperspectral confocal fluorescence microscopy, which enables the capability to quickly and accurately identify and characterize the unique autofluorescence spectra from different Candida species with up to 84% accuracy when grown in conditions that closely mimic physiological conditions.

Cerebral Candidal Abscess and Bovine Viral Diarrhoea Virus Infection in an Aborted Bovine Fetus.

PubMed

Vilander, A C; Niles, G A; Frank, C B

2016-01-01

Candida species are opportunistic fungi associated with immunosuppression and are the most commonly isolated fungal pathogens from the human central nervous system. Invasive candidiasis is reported uncommonly in animals and there have only been two reports of candidal infection of the brain. This report presents a case of a cerebral candidal abscess in an aborted late-term calf co-infected with bovine viral diarrhoea virus. Candida etchellsii, a species not previously identified as pathogenic, was identified as the causative agent by polymerase chain reaction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of fungi in shotgun metagenomics datasets

PubMed Central

Donovan, Paul D.; Gonzalez, Gabriel; Higgins, Desmond G.

2018-01-01

Metagenomics uses nucleic acid sequencing to characterize species diversity in different niches such as environmental biomes or the human microbiome. Most studies have used 16S rRNA amplicon sequencing to identify bacteria. However, the decreasing cost of sequencing has resulted in a gradual shift away from amplicon analyses and towards shotgun metagenomic sequencing. Shotgun metagenomic data can be used to identify a wide range of species, but have rarely been applied to fungal identification. Here, we develop a sequence classification pipeline, FindFungi, and use it to identify fungal sequences in public metagenome datasets. We focus primarily on animal metagenomes, especially those from pig and mouse microbiomes. We identified fungi in 39 of 70 datasets comprising 71 fungal species. At least 11 pathogenic species with zoonotic potential were identified, including Candida tropicalis. We identified Pseudogymnoascus species from 13 Antarctic soil samples initially analyzed for the presence of bacteria capable of degrading diesel oil. We also show that Candida tropicalis and Candida loboi are likely the same species. In addition, we identify several examples where contaminating DNA was erroneously included in fungal genome assemblies. PMID:29444186

Oropharyngeal candidiasis in head and neck cancer patients in Iran: Species identification, antifungal susceptibility and pathogenic characterization.

PubMed

Jahanshiri, Z; Manifar, S; Moosa, H; Asghari-Paskiabi, F; Mahmoodzadeh, H; Shams-Ghahfarokhi, M; Razzaghi-Abyaneh, M

2018-06-01

Oropharyngeal candidiasis (OPC) is the most frequent opportunistic fungal infection in head and neck cancer patients. This study was done to identify the Candida species, which cause OPC, and to evaluate their antifungal susceptibility pattern and pathogenic characteristics in Iranian head and neck cancer patients treated by radiotherapy. The oral clinical samples were determined by culturing on CHROMagar, carbohydrate assimilation and ITS sequencing methods. Biofilm formation, phospholipase and proteinase activity and antifungal susceptibility were examined too. Among 54 patients with confirmed OPC, 39 (72.22%) patients were male and 15 (27.77%) were female. The most frequently Candida species from a total of 60 isolates was C. albicans (53.3%), followed by C. tropicalis (21.66%), C. glabrata (15%), C. kefyr (5%) and C. dubliniensis (1.66%). All the isolates were high-producers of biofilm. All of Candida isolates were proteinase positive and 47 isolates (81.04%) represented phospholipase activity. The maximum and minimum rates of antifungal resistance belonged to ketoconazole (93.75% of C. albicans and 89.28% of Candida non-albicans) and fluconazole (62.50% and 42.85% of C. albicans and Candida non-albicans), respectively. The most effective antifungal against all candida isolates was fluconazole. Our data can estimate abundance of OPC in male and female head and neck cancer patients and is helpful to use effective strategies for antifungal treatment, prophylaxis, and preventive therapies in these patients. Copyright © 2018. Published by Elsevier Masson SAS.

Triclosan Enhances the Clearing of Pathogenic Intracellular Salmonella or Candida albicans but Disturbs the Intestinal Microbiota through mTOR-Independent Autophagy.

PubMed

Wang, Chao; Yu, Zhongyang; Shi, Xiaochen; Tang, Xudong; Wang, Yang; Wang, Xueyan; An, Yanan; Li, Shulin; Li, Yan; Wang, Xuefei; Luan, Wenjing; Chen, Zhaobin; Liu, Mingyuan; Yu, Lu

2018-01-01

Triclosan (TCS) is a broad-spectrum antimicrobial agent, whose well-known antibacterial mechanism is inhibiting lipid synthesis. Autophagy, an innate immune response, is an intracellular process that delivers the cargo including pathogens to lysosomes for degradation. In this study, we first demonstrated that TCS induced autophagy in a dose-dependent manner in non-phagocytic cells (HeLa) and in macrophages (Raw264.7) and in vivo . The western blot results also revealed that TCS induced autophagy via the AMPK/ULK1 and JNK/ERK/p38 pathways independent of mTOR. The immunofluorescence results indicated that TCS up-regulated the expression of the ubiquitin receptors NDP52 and p62 and strengthened the co-localization of these receptors with Salmonella enterica Typhimurium ( S . typhimurium) or Candida albicans ( C. albicans ) in infected MΦ cells. In addition, sub-lethal concentrations of TCS enhanced the clearing of the pathogens S . typhimurium or C. albicans in infected MΦ and in corresponding mouse infection models in vivo . Specifically, we found that a sub-inhibitory concentration of TCS induced autophagy, leading to an imbalance of the intestinal microflora in mice through the analysis of 16s rRNA Sequencing. Together, these results demonstrated that TCS induced autophagy, which enhanced the killing against pathogenic S . typhimurium or C. albicans within mammal cells but broke the balance of the intestinal microflora.

Cell wall proteome of pathogenic fungi.

PubMed

Karkowska-Kuleta, Justyna; Kozik, Andrzej

2015-01-01

A fast development of a wide variety of proteomic techniques supported by mass spectrometry coupled with high performance liquid chromatography has been observed in recent years. It significantly contributes to the progress in research on the cell wall, very important part of the cells of pathogenic fungi. This complicated structure composed of different polysaccharides, proteins, lipids and melanin, plays a key role in interactions with the host during infection. Changes in the set of the surface-exposed proteins under different environmental conditions provide an effective way for pathogens to respond, adapt and survive in the new niches of infection. This work summarizes the current state of knowledge on proteins, studied both qualitatively and quantitatively, and found within the cell wall of fungal pathogens for humans, including Candida albicans, Candida glabrata, Aspergillus fumigatus, Cryptococcus neoformans and other medically important fungi. The described proteomic studies involved the isolation and fractionation of particular sets of proteins of interest with various techniques, often based on differences in their linkages to the polysaccharide scaffold. Furthermore, the proteinaceous contents of extracellular vesicles ("virulence bags") of C. albicans, C. neoformans, Histoplasma capsulatum and Paracoccidioides brasiliensis are compared, because their production can partially explain the problem of non-classical protein secretion by fungi. The role assigned to surface-exposed proteins in pathogenesis of fungal infections is enormously high, thus justifying the need for further investigation of cell wall proteomes.

Complement and innate immune evasion strategies of the human pathogenic fungus Candida albicans.

PubMed

Luo, Shanshan; Skerka, Christine; Kurzai, Oliver; Zipfel, Peter F

2013-12-15

Candida albicans is a medically important fungus that can cause a wide range of diseases ranging from superficial infections to disseminated disease, which manifests primarily in immuno-compromised individuals. Despite the currently applied anti-fungal therapies, both mortality and morbidity caused by this human pathogenic fungus are still unacceptably high. Therefore new prophylactic and therapeutic strategies are urgently needed to prevent fungal infection. In order to define new targets for combating fungal disease, there is a need to understand the immune evasion strategies of C. albicans in detail. In this review, we summarize different sophisticated immune evasion strategies that are utilized by C. albicans. The description of the molecular mechanisms used for immune evasion does on one hand help to understand the infection process, and on the other hand provides valuable information to define new strategies and diagnostic approaches to fight and interfere with Candida infections. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Case Report of Penile Infection Caused by Fluconazole- and Terbinafine-Resistant Candida albicans.

PubMed

Hu, Yongxuan; Hu, Yanqing; Lu, Yan; Huang, Shiyun; Liu, Kangxing; Han, Xue; Mao, Zuhao; Wu, Zhong; Zhou, Xianyi

2017-04-01

Candida albicans is the most common pathogen that causes balanoposthitis. It often causes recurrence of symptoms probably due to its antifungal resistance. A significant number of balanitis Candida albicans isolates are resistant to azole and terbinafine antifungal agents in vitro. However, balanoposthitis caused by fluconazole- and terbinafine-resistant Candida albicans has rarely been reported. Here, we describe a case of a recurrent penile infection caused by fluconazole- and terbinafine-resistant Candida albicans, as well as the treatments administered to this patient. The isolate from the patient was tested for drug susceptibility in vitro. It was sensitive to itraconazole, voriconazole, clotrimazole and amphotericin B, but not to terbinafine and fluconazole. Thus, oral itraconazole was administrated to this patient with resistant Candida albicans penile infection. The symptoms were improved, and mycological examination result was negative. Follow-up treatment of this patient for 3 months showed no recurrence.

Synergistic Effects and Mechanisms of Budesonide in Combination with Fluconazole against Resistant Candida albicans.

PubMed

Li, Xiuyun; Yu, Cuixiang; Huang, Xin; Sun, Shujuan

2016-01-01

Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases in the clinic. The emergence of drug resistance in Candida albicans has become a noteworthy phenomenon due to the extensive use of antifungal agents and the development of biofilms. This study showed that budesonide potentiates the antifungal effect of fluconazole against fluconazole-resistant Candida albicans strains both in vitro and in vivo. In addition, our results demonstrated, for the first time, that the combination of fluconazole and budesonide can reverse the resistance of Candida albicans by inhibiting the function of drug transporters, reducing the formation of biofilms, promoting apoptosis and inhibiting the activity of extracellular phospholipases. This is the first study implicating the effects and mechanisms of budesonide against Candida albicans alone or in combination with fluconazole, which may ultimately lead to the identification of new potential antifungal targets.

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

[Yeast species in vulvovaginitis candidosa].

PubMed

Nemes-Nikodém, Éva; Tamási, Béla; Mihalik, Noémi; Ostorházi, Eszter

2015-01-04

Vulvovaginal candidiasis is the most common mycosis, however, the available information about antifungal susceptibilities of these yeasts is limited. To compare the gold standard fungal culture with a new molecular identification method and report the incidence of yeast species in vulvovaginitis candidosa. The authors studied 370 yeasts isolated from vulvovaginal candidiasis and identified them by phenotypic and molecular methods. The most common species was Candida albicans (85%), followed by Candida glabrata, and other Candida species. At present there are no recommendations for the evaluation of antifungal susceptibility of pathogenic fungal species occurring in vulvovaginal candidiasis and the natural antifungal resistance of the different species is known only. Matrix Assisted Laser Desorption Ionization Time of Flight identification can be used to differentiate the fluconazole resistant Candida dubliniensis and the sensitive Candida albicans strains.

An in vitro study of antifungal drug susceptibility of Candida species isolated from human immunodeficiency virus seropositive and human immunodeficiency virus seronegative individuals in Lucknow population Uttar Pradesh.

PubMed

Dar, Mohammad Shafi; Sreedar, Gadiputi; Shukla, Abhilasha; Gupta, Prashant; Rehan, Ahmad Danish; George, Jiji

2015-01-01

Candidiasis is the most common opportunistic infection in human immunodeficiency virus (HIV) seropositive patients, starting from asymptomatic colonization to pathogenic forms and gradual colonization of non-albicans in patients with advanced immunosuppression leads to resistance for azole group of antifungal drugs with high rate of morbidity and mortality. To isolate the Candida species and determine of antifungal drug susceptibility against fluconazole, itraconazole, nystatin, amphotericin B, and clotrimazolein HIV seropositive and control individuals, with or without clinical oropharyngeal candidiasis (OPC). Includes samples from faucial region of 70 subjects with and without clinical candidiasis in HIV seropositive and controls were aseptically inoculated onto Sabaraud's Dextrose Agar media and yeasts were identified for the specific species by Corn Meal Agar, sugar fermentation and heat tolerance tests. Antifungal drug susceptibility of the isolated species was done against above-mentioned drugs by E-test and disc diffusion method. The commonly isolated species in HIV seropositive and controls were Candida albicans, Candida glabrata and Candida tropicalis Candida guilliermondii and Candida dubliniensis isolated only in HIV seropositive patients. Susceptibility against selected antifungal drugs was observed more in HIV-negative individuals whereas susceptible dose-dependent and resistance were predominant in HIV-positive patients. Resistance is the major problem in the therapy of OPC, especially in HIV seropositive patients due to aggressive and prolonged use of antifungal agents, therefore, our study emphasizes the need for antifungal drug susceptibility testing whenever antifungal treatment is desired, especially in HIV-infected subjects.

Significance of hyphae formation in virulence of Candida tropicalis and transcriptomic analysis of hyphal cells.

PubMed

Jiang, Cen; Li, Zhen; Zhang, Lihua; Tian, Yuan; Dong, Danfeng; Peng, Yibing

2016-11-01

Recently, the proportion of Candida tropicalis in clinical isolates has significantly increased. Some C. tropicalis strains colonize the skin or mucosal surfaces as commensals; others trigger invasive infection. To date, the pathogenicity of C. tropicalis has not been thoroughly researched. This study reports several virulence factors, including biofilm and hyphae formation, proteinase, phospholipase, lipase and hemolytic activity, in 52 clinical isolates of C. tropicalis collected from five hospitals in four provinces of China. Some C. tropicalis tended to produce more hyphae than others in the same circumstance. Six C. tropicalis strains with different morphologies were injected into mice via the tail vein, and the survival proportions and fungal burdens of the strains were evaluated. Hyphal production by C. tropicalis was associated with stronger virulence. RNA sequencing revealed that C. tropicalis with more hyphae up-regulated several genes involved in morphological differentiation and oxidative response, including IF2, Atx1, and Sod2. It appears that hyphal formation plays a vital role in the pathogenicity of C. tropicalis, and interacts with the oxidative stress response to strengthen the organism's virulence. Copyright © 2016 Elsevier GmbH. All rights reserved.

Global Analysis of the Fungal Microbiome in Cystic Fibrosis Patients Reveals Loss of Function of the Transcriptional Repressor Nrg1 as a Mechanism of Pathogen Adaptation

PubMed Central

Kim, Sang Hu; Clark, Shawn T.; Surendra, Anuradha; Copeland, Julia K.; Wang, Pauline W.; Ammar, Ron; Collins, Cathy; Tullis, D. Elizabeth; Nislow, Corey; Hwang, David M.; Guttman, David S.; Cowen, Leah E.

2015-01-01

The microbiome shapes diverse facets of human biology and disease, with the importance of fungi only beginning to be appreciated. Microbial communities infiltrate diverse anatomical sites as with the respiratory tract of healthy humans and those with diseases such as cystic fibrosis, where chronic colonization and infection lead to clinical decline. Although fungi are frequently recovered from cystic fibrosis patient sputum samples and have been associated with deterioration of lung function, understanding of species and population dynamics remains in its infancy. Here, we coupled high-throughput sequencing of the ribosomal RNA internal transcribed spacer 1 (ITS1) with phenotypic and genotypic analyses of fungi from 89 sputum samples from 28 cystic fibrosis patients. Fungal communities defined by sequencing were concordant with those defined by culture-based analyses of 1,603 isolates from the same samples. Different patients harbored distinct fungal communities. There were detectable trends, however, including colonization with Candida and Aspergillus species, which was not perturbed by clinical exacerbation or treatment. We identified considerable inter- and intra-species phenotypic variation in traits important for host adaptation, including antifungal drug resistance and morphogenesis. While variation in drug resistance was largely between species, striking variation in morphogenesis emerged within Candida species. Filamentation was uncoupled from inducing cues in 28 Candida isolates recovered from six patients. The filamentous isolates were resistant to the filamentation-repressive effects of Pseudomonas aeruginosa, implicating inter-kingdom interactions as the selective force. Genome sequencing revealed that all but one of the filamentous isolates harbored mutations in the transcriptional repressor NRG1; such mutations were necessary and sufficient for the filamentous phenotype. Six independent nrg1 mutations arose in Candida isolates from different patients, providing a poignant example of parallel evolution. Together, this combined clinical-genomic approach provides a high-resolution portrait of the fungal microbiome of cystic fibrosis patient lungs and identifies a genetic basis of pathogen adaptation. PMID:26588216

Global Analysis of the Fungal Microbiome in Cystic Fibrosis Patients Reveals Loss of Function of the Transcriptional Repressor Nrg1 as a Mechanism of Pathogen Adaptation.

PubMed

Kim, Sang Hu; Clark, Shawn T; Surendra, Anuradha; Copeland, Julia K; Wang, Pauline W; Ammar, Ron; Collins, Cathy; Tullis, D Elizabeth; Nislow, Corey; Hwang, David M; Guttman, David S; Cowen, Leah E

2015-11-01

The microbiome shapes diverse facets of human biology and disease, with the importance of fungi only beginning to be appreciated. Microbial communities infiltrate diverse anatomical sites as with the respiratory tract of healthy humans and those with diseases such as cystic fibrosis, where chronic colonization and infection lead to clinical decline. Although fungi are frequently recovered from cystic fibrosis patient sputum samples and have been associated with deterioration of lung function, understanding of species and population dynamics remains in its infancy. Here, we coupled high-throughput sequencing of the ribosomal RNA internal transcribed spacer 1 (ITS1) with phenotypic and genotypic analyses of fungi from 89 sputum samples from 28 cystic fibrosis patients. Fungal communities defined by sequencing were concordant with those defined by culture-based analyses of 1,603 isolates from the same samples. Different patients harbored distinct fungal communities. There were detectable trends, however, including colonization with Candida and Aspergillus species, which was not perturbed by clinical exacerbation or treatment. We identified considerable inter- and intra-species phenotypic variation in traits important for host adaptation, including antifungal drug resistance and morphogenesis. While variation in drug resistance was largely between species, striking variation in morphogenesis emerged within Candida species. Filamentation was uncoupled from inducing cues in 28 Candida isolates recovered from six patients. The filamentous isolates were resistant to the filamentation-repressive effects of Pseudomonas aeruginosa, implicating inter-kingdom interactions as the selective force. Genome sequencing revealed that all but one of the filamentous isolates harbored mutations in the transcriptional repressor NRG1; such mutations were necessary and sufficient for the filamentous phenotype. Six independent nrg1 mutations arose in Candida isolates from different patients, providing a poignant example of parallel evolution. Together, this combined clinical-genomic approach provides a high-resolution portrait of the fungal microbiome of cystic fibrosis patient lungs and identifies a genetic basis of pathogen adaptation.

A Novel Flucytosine-Resistant Yeast Species, Candida pseudoaaseri, Causes Disease in a Cancer Patient ▿

PubMed Central

Pfüller, Roland; Gräser, Yvonne; Erhard, Marcel; Groenewald, Marizeth

2011-01-01

Some members of the genus Candida are among the most common human fungal pathogens and cause serious diseases especially in immunocompromised people. A yeast was isolated from a blood culture from an immunocompromised cancer patient who suffered from acute pneumonia. The growth characteristics of the yeast on CHROMagar Candida were similar to those of Candida tropicalis, whereas the API ID 32C system identified the yeast as Candida silvicola. On the basis of the nucleotide divergence in the D1/D2 domain of the 26S nuclear rRNA (nrRNA) gene, as well as the internal transcribed spacer (ITS) domain of the nrRNA gene region, a new species, Candida pseudoaaseri sp. nov. with type strain VK065094 (CBS 11170T), which was found to be closely related to Candida aaseri, is proposed. While C. aaseri strains were susceptible to all tested antifungals, the new species is resistant to flucytosine and may also be distinguished from C. aaseri by its ability to assimilate l-rhamnose, whereas its colony morphology on CHROMagar Candida may be helpful for differentiation. PMID:21976765

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 pathogenesis. During the course of an infection, the prevalence of each Candida species may change over time due to differences in metabolism and in the resistance of each species to antifungal therapies. Therefore, it is necessary to understand the dynamics between C. albicans and C. glabrata in coculture to develop better therapeutic strategies against Candida infections. Existing in vitro work has focused on understanding how an equal-part culture of C. albicans and C. glabrata impacts biofilm formation and pathogenesis. What is not understood, and what is investigated in this work, is how the composition of Candida species in coculture impacts overall biofilm formation, virulence gene expression, and the therapeutic treatment of biofilms. Copyright © 2018 American Society for Microbiology.

PCR-denaturing gradient gel electrophoresis analysis of microbial community in soy-daddawa, a Nigerian fermented soybean (Glycine max (L.) Merr.) condiment.

PubMed

Ezeokoli, Obinna T; Gupta, Arvind K; Mienie, Charlotte; Popoola, Temitope O S; Bezuidenhout, Cornelius C

2016-03-02

Soy-daddawa, a fermented soybean (Glycine max (L.) Merr.) condiment, plays a significant role in the culinary practice of West Africa. It is essential to understand the microbial community of soy-daddawa for a successful starter culture application. This study investigated the microbial community structure of soy-daddawa samples collected from Nigerian markets, by PCR-denaturing gradient gel electrophoresis (DGGE) targeting the V3-V5 region of the 16S rRNA gene of bacteria and internal transcribed spacer 2 (ITS2) region of fungi. Six bacterial and 16 fungal (nine yeasts and seven molds) operational taxonomic units (OTUs)/species were obtained at 97% sequence similarity. Taxonomic assignments revealed that bacterial OTUs belonged to the phyla Firmicutes and Actinobacteria, and included species from the genera Atopostipes, Bacillus, Brevibacterium and Nosocomiicoccus. Densitometric analysis of DGGE image/bands revealed that Bacillus spp. were the dominant OTU/species in terms of population numbers. Fungal OTUs belonged to the phyla Ascomycota and Zygomycota, and included species from the genera, Alternaria, Aspergillus, Candida, Cladosporium, Dokmaia, Issatchenkia, Kodamaea, Lecythophora, Phoma, Pichia, Rhizopus, Saccharomyces and Starmerella. The majority of fungal species have not been previously reported in soy-daddawa. Potential opportunistic human pathogens such as Atopostipes suicloacalis, Candida rugosa, Candida tropicalis, and Kodamaea ohmeri were detected. Variation in soy-daddawa microbial communities amongst samples and presence of potential opportunistic pathogens emphasises the need for starter culture employment and good handling practices in soy-daddawa processing. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular mechanisms of mucocutaneous immunity against Candida and Staphylococci

PubMed Central

Maródi, László; Cypowyj, Sophie; Tóth, Beáta; Chernyshova, Liudmyla; Puel, Anne; Casanova, Jean-Laurent

2013-01-01

Signal transducer and activator of transcription (STAT) proteins are key components of the innate and adaptive immune responses to pathogenic microorganisms. Recent research on primary immunodeficiency disorders and the identification of patients carrying germline mutations in STAT1, STAT3, and STAT5B have highlighted the role of human STATs in host defense against various viruses, bacteria, and fungi. Mutations in STAT1 and STAT3 may disrupt various cytokine pathways that control mucocutaneous immunity against Candida species, especially Candida albicans, and Staphylococci, especially Staphylococcus aureus. Here, we consider inborn errors of immunity arising from mutations in either STAT1 or STAT3 that affect mucocutaneous immunity to Candida and Staphylococci. PMID:23040277

Hyperspectral fluorescence microscopy detects autofluorescent factors that can be exploited as a diagnostic method for Candida species differentiation

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

Graus, Matthew S.; Neumann, Aaron K.; Timlin, Jerilyn A.

Fungi in the Candida genus are the most common fungal pathogens. They not only cause high morbidity and mortality but can also cost billions of dollars in healthcare. To alleviate this burden, early and accurate identification of Candida species is necessary. However, standard identification procedures can take days and have a large false negative error. The method described in this study takes advantage of hyperspectral confocal fluorescence microscopy, which enables the capability to quickly and accurately identify and characterize the unique autofluorescence spectra from different Candida species with up to 84% accuracy when grown in conditions that closely mimic physiologicalmore » conditions.« less

Hyperspectral fluorescence microscopy detects autofluorescent factors that can be exploited as a diagnostic method for Candida species differentiation

DOE PAGES

Graus, Matthew S.; Neumann, Aaron K.; Timlin, Jerilyn A.

2017-01-05

Fungi in the Candida genus are the most common fungal pathogens. They not only cause high morbidity and mortality but can also cost billions of dollars in healthcare. To alleviate this burden, early and accurate identification of Candida species is necessary. However, standard identification procedures can take days and have a large false negative error. The method described in this study takes advantage of hyperspectral confocal fluorescence microscopy, which enables the capability to quickly and accurately identify and characterize the unique autofluorescence spectra from different Candida species with up to 84% accuracy when grown in conditions that closely mimic physiologicalmore » conditions.« less

Betamethasone augments the antifungal effect of menadione--towards a novel anti-Candida albicans combination therapy.

PubMed

Jakab, Ágnes; Emri, Tamás; Sipos, Lilla; Kiss, Ágnes; Kovács, Renátó; Dombrádi, Viktor; Kemény-Beke, Ádám; Balla, József; Majoros, László; Pócsi, István

2015-08-01

The fluorinated glucocorticoid betamethasone stimulated both the extracellular phospholipase production and hypha formation of the opportunistic human pathogen Candida albicans and also decreased the efficiency of the polyene antimycotics amphotericin B and nystatin against C. albicans in a dose-dependent manner. Importantly, betamethasone increased synergistically the anti-Candida activity of the oxidative stress generating agent menadione, which may be exploited in future combination therapies to prevent or cure C. albicans infections, in the field of dermatology. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular identification and antifungal susceptibility profile of Candida species isolated from patients with vulvovaginitis in Tehran, Iran.

PubMed

Sharifynia, Somayeh; Falahati, Mehraban; Akhlaghi, Lame; Foroumadi, Alireza; Fateh, Roohollah

2017-01-01

Rapid and accurate identification and evaluation of antifungal susceptibility pattern of Candida isolates are crucial to determine suitable antifungal drugs for the treatment of patients with vulvovaginitis candidiasis. Vaginal samples were collected from 150 women with suspicious vaginal candidiasis, and then cultured on Sabouraoud's Dextrose Agar with chloramphenicol to isolate Candida species. After identification of Candida isolates using polymerase chain reaction-restriction fragment length polymorphism technique, antifungal susceptibility testing of four azolic antifungal drugs was carried out using broth microdilution method according to the CLSI M27-A3. Candida species were isolated from eighty suspected patients (61.79%). The most common pathogen was Candida albicans (63.75%). Resistance to fluconazole and ketoconazole was observed in 27.5% and 23.75% of Candida isolates, respectively, and only 2% of Candida isolates were resistant to miconazole. Interestingly, resistance to fluconazole in C. albicans was more than other Candida species. The results indicated that therapy should be selected according to the antifungal susceptibility tests for the prevention of treatment failure and miconazole therapy can be considered as the best therapeutic choice in the management of vulvovaginitis.

Molecular identification and antifungal susceptibility profile of Candida species isolated from patients with vulvovaginitis in Tehran, Iran

PubMed Central

Sharifynia, Somayeh; Falahati, Mehraban; Akhlaghi, Lame; Foroumadi, Alireza; Fateh, Roohollah

2017-01-01

Background: Rapid and accurate identification and evaluation of antifungal susceptibility pattern of Candida isolates are crucial to determine suitable antifungal drugs for the treatment of patients with vulvovaginitis candidiasis. Materials and Methods: Vaginal samples were collected from 150 women with suspicious vaginal candidiasis, and then cultured on Sabouraoud's Dextrose Agar with chloramphenicol to isolate Candida species. After identification of Candida isolates using polymerase chain reaction-restriction fragment length polymorphism technique, antifungal susceptibility testing of four azolic antifungal drugs was carried out using broth microdilution method according to the CLSI M27-A3. Results: Candida species were isolated from eighty suspected patients (61.79%). The most common pathogen was Candida albicans (63.75%). Resistance to fluconazole and ketoconazole was observed in 27.5% and 23.75% of Candida isolates, respectively, and only 2% of Candida isolates were resistant to miconazole. Interestingly, resistance to fluconazole in C. albicans was more than other Candida species. Conclusion: The results indicated that therapy should be selected according to the antifungal susceptibility tests for the prevention of treatment failure and miconazole therapy can be considered as the best therapeutic choice in the management of vulvovaginitis. PMID:29387119

Stimulation with lysates of Aspergillus terreus, Candida krusei and Rhizopus oryzae maximizes cross-reactivity of anti-fungal T cells.

PubMed

Deo, Shivashni S; Virassamy, Balaji; Halliday, Catriona; Clancy, Leighton; Chen, Sharon; Meyer, Wieland; Sorrell, Tania C; Gottlieb, David J

2016-01-01

Invasive fungal diseases caused by filamentous fungi and yeasts are significant causes of morbidity and mortality in immunosuppressed hematology patients. We previously published a method to expand Aspergillus fumigatus-specific T cells for clinical cell therapy. In the present study, we investigated expansion of T cells specific for other fungal pathogens and creation of a broadly reactive panfungal T-cell product. Fungal strains selected were those frequently observed in the clinical hematology setting and included Aspergillus, Candida, Fusarium, Rhizopus and Lomentospora/Scedosporium. Four T-cell cultures specific to each fungus were established. We selected lysates of Aspergillus terreus, Candida krusei and Rhizopus oryzae to expand panfungal T cells. Allelic restriction of anti-fungal activity was determined through the use of specific major histocompatibility complex class II-blocking antibodies. Individual T-cell cultures specific to each fungus could be expanded in vitro, generating predominantly CD4(+) T cells of which 8% to 20% were fungus-specific. We successfully expanded panfungal T cells from the peripheral blood (n = 8) and granulocyte-colony-stimulating factor-primed stem cell products (n = 3) of normal donors by using a combination of lysates from Aspergillus terreus, Candida krusei and Rhizopus oryzae. Anti-fungal activity was mediated through human leukocyte antigen (HLA)-DR alleles and was maintained when antigen-presenting cells from partially HLA-DRB1-matched donors were used to stimulate T cells. We demonstrate a method to manufacture panfungal T-cell products with specificity against a range of clinical fungal pathogens by use of the blood and stem cells of healthy donors as the starting material. The safety and efficacy of these products will need to be tested clinically. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Urinary tract infections and Candida albicans.

PubMed

Behzadi, Payam; Behzadi, Elham; Ranjbar, Reza

2015-01-01

Urinary tract candidiasis is known as the most frequent nosocomial fungal infection worldwide. Candida albicans is the most common cause of nosocomial fungal urinary tract infections; however, a rapid change in the distribution of Candida species is undergoing. Simultaneously, the increase of urinary tract candidiasis has led to the appearance of antifungal resistant Candida species. In this review, we have an in depth look into Candida albicans uropathogenesis and distribution of the three most frequent Candida species contributing to urinary tract candidiasis in different countries around the world. For writing this review, Google Scholar -a scholarly search engine- (http://scholar.google.com/) and PubMed database (http://www.ncbi.nlm.nih.gov/pubmed/) were used. The most recently published original articles and reviews of literature relating to the first three Candida species causing urinary tract infections in different countries and the pathogenicity of Candida albicans were selected and studied. Although some studies show rapid changes in the uropathogenesis of Candida species causing urinary tract infections in some countries, Candida albicans is still the most important cause of candidal urinary tract infections. Despite the ranking of Candida albicans as the dominant species for urinary tract candidiasis, specific changes have occurred in some countries. At this time, it is important to continue the surveillance related to Candida species causing urinary tract infections to prevent, control and treat urinary tract candidiasis in future.

Evaluation of a rapid, quantitative real-time PCR method for enumeration of pathogenic Candida cells in water

USGS Publications Warehouse

Brinkman, Nichole E.; Haugland, Richard A.; Wymer, Larry J.; Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Vesper, Stephen J.

2003-01-01

Quantitative PCR (QPCR) technology, incorporating fluorigenic 5′ nuclease (TaqMan) chemistry, was utilized for the specific detection and quantification of six pathogenic species of Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis, C. glabrata and C. lusitaniae) in water. Known numbers of target cells were added to distilled and tap water samples, filtered, and disrupted directly on the membranes for recovery of DNA for QPCR analysis. The assay's sensitivities were between one and three cells per filter. The accuracy of the cell estimates was between 50 and 200% of their true value (95% confidence level). In similar tests with surface water samples, the presence of PCR inhibitory compounds necessitated further purification and/or dilution of the DNA extracts, with resultant reductions in sensitivity but generally not in quantitative accuracy. Analyses of a series of freshwater samples collected from a recreational beach showed positive correlations between the QPCR results and colony counts of the corresponding target species. Positive correlations were also seen between the cell quantities of the target Candida species detected in these analyses and colony counts of Enterococcus organisms. With a combined sample processing and analysis time of less than 4 h, this method shows great promise as a tool for rapidly assessing potential exposures to waterborne pathogenic Candida species from drinking and recreational waters and may have applications in the detection of fecal pollution.

Translocation of cell-penetrating peptides into Candida fungal pathogens.

PubMed

Gong, Zifan; Karlsson, Amy J

2017-09-01

Cell-penetrating peptides (CPPs) are small peptides capable of crossing cellular membranes while carrying molecular cargo. Although they have been widely studied for their ability to translocate nucleic acids, small molecules, and proteins into mammalian cells, studies of their interaction with fungal cells are limited. In this work, we evaluated the translocation of eleven fluorescently labeled peptides into the important human fungal pathogens Candida albicans and C. glabrata and explored the mechanisms of translocation. Seven of these peptides (cecropin B, penetratin, pVEC, MAP, SynB, (KFF) 3 K, and MPG) exhibited substantial translocation (>80% of cells) into both species in a concentration-dependent manner, and an additional peptide (TP-10) exhibiting strong translocation into only C. glabrata. Vacuoles were involved in translocation and intracellular trafficking of the peptides in the fungal cells and, for some peptides, escape from the vacuoles and localization in the cytosol were correlated to toxicity toward the fungal cells. Endocytosis was involved in the translocation of cecropin B, MAP, SynB, MPG, (KFF) 3 K, and TP-10, and cecropin B, penetratin, pVEC, and MAP caused membrane permeabilization during translocation. These results indicate the involvement of multiple translocation mechanisms for some CPPs. Although high levels of translocation were typically associated with toxicity of the peptides toward the fungal cells, SynB was translocated efficiently into Candida cells at concentrations that led to minimal toxicity. Our work highlights the potential of CPPs in delivering antifungal molecules and other bioactive cargo to Candida pathogens. © 2017 The Protein Society.

Mitochondrial Telomeres as Molecular Markers for Identification of the Opportunistic Yeast Pathogen Candida parapsilosis

PubMed Central

Nosek, Jozef; Tomáška, L'ubomír; Ryčovská, Adriana; Fukuhara, Hiroshi

2002-01-01

Recent studies have demonstrated that a large number of organisms carry linear mitochondrial DNA molecules possessing specialized telomeric structures at their ends. Based on this specific structural feature of linear mitochondrial genomes, we have developed an approach for identification of the opportunistic yeast pathogen Candida parapsilosis. The strategy for identification of C. parapsilosis strains is based on PCR amplification of specific DNA sequences derived from the mitochondrial telomere region. This assay is complemented by immunodetection of a protein component of mitochondrial telomeres. The results demonstrate that mitochondrial telomeres represent specific molecular markers with potential applications in yeast diagnostics and taxonomy. PMID:11923346

The Role of PCR in the Diagnosis of Candida Vulvovaginitis-a New Gold Standard?

PubMed

Sobel, J D; Akins, Robert A

2015-06-01

PCR is recognized as a reliable technique for detection of all types of microorganisms. Being highly objective and reproducible also sensitive and specific, PCR is now widely used for sexually transmitted infection (STI) diagnosis. Potential, however, exists for detecting non-pathogens, and not identifying a pathogenic state decreases specificity or clinical significance. PCR Candida tests of vaginal specimens are now widely available and frequently used offering a modest to moderate increase in sensitivity and are likely to replace traditional culture and DNA homology testing. Nevertheless, there remain considerable gaps in our knowledge regarding the usefulness and applications of these expensive tests.

Development of a chip-based multiplexed immunoassay using liposomal nanovesicles and its application in the detection of pathogens causing female lower genital tract infections.

PubMed

Su, Wen-Hsiang; Ho, Tien-Yu; Tsou, Tsung-Shan; Lee, Wen-Ling; Wang, Kuan-Chin; Yu, Yuan-Yi; Chen, Tien-Jui; Tan, Chia-Hsuan; Kuo, Cheng-Deng; Chen, Chien-Sheng; Wang, Peng-Hui

2013-03-01

Cervicovaginitis is a highly prevalent disease that is a burden on healthcare globally. Immediate and adequate treatment can eradicate the infection and block subsequent complications. The feasibility of achip-based multiplexed immunoassay using liposomal nanovesicles was tested. A multiplexed immunoassay chip containing five antibodies for five pathogens (Chlamydia trachomatis, Escherichia coli, Neisseria gonorrhoeae, Streptococcus agalactiae, and Candida albicans) was established and tested. Four patients with spiking of candidiasis were enrolled. The difference between positive and negative readings was evaluated using the paired Student t test. The detection threshold of Candida in this microarray was 100,000 CFU/mL in a vaginal sample, and the time required for the whole procedure was 3 hours. The testing of the four patients showed 100% for both sensitivity and specificity. This microarray chip was a rapid, easy, inexpensive and sensitive tool for detecting female lower genital tract Candida infection in a one-time vaginal sampling process, although the data on the four other pathogens were still unavailable. A larger population study is encouraged to test the validity of this multiplexed immunoassay chip. Copyright © 2013. Published by Elsevier B.V.

[Phenotypic and genotypic identification of Candida strains isolated as nosocomial pathogens].

PubMed

Sahiner, Fatih; Ergünay, Koray; Ozyurt, Mustafa; Ardıç, Nurittin; Hoşbul, Tuğrul; Haznedaroğlu, Tunçer

2011-07-01

Over the last decade, there have been important changes in the epidemiology of Candida infections and antifungal agents used to treat these infections. In recent years, Candida species have emerged as important causes of invasive infections among patients in intensive care units. One of the main goals of this study was to evaluate the molecular epidemiology of infectious Candida species isolated in our hospital and accordingly supply data for hospital infection (HI) control. The other aim of this study was to evaluate effectiveness and practical applicability of traditional and molecular methods used to identify Candida isolates to the species level. A total of 77 Candida strains that were isolated from various clinical specimens of 60 hospitalized patients (29 male, 24 female; 7 were children) were included in the study. Fifty-seven (74%) of those isolates were defined as HI agents according to Centers for Disease Control and Prevention (CDC) criteria. The most common Candida species identified as agents of HI were C.albicans (22; 38.6%), followed by C.tropicalis (14; 24.6%), C.parapsilosis (13; 22.8%), C.glabrata (7; 12.3%) and Candida spp. (1; 1.75%). It was determined that bloodstream (26; 45.6%) and urinary tract infections (24; 42.1%) were the most frequently encountered nosocomial infections caused by Candida species. In addition it was detected that the most frequent causative agent of bloodstream infections was C.parapsilosis (10; 38.5%) and of urinary tract infections was C.albicans (12; 50%). The evaluation of advantages and disadvantages of traditional phenotypic methods [germ tube formation, chlamydospore formation in corn meal agar, growth at 45°C, colony characteristics on CHROMagar Candida medium, carbohydrate assimilation properties detected by API ID 32C (BioMerieux, France) system] and some molecular techniques [polymerase chain reaction (PCR) by using ITS-1, ITS-3 and ITS 4 primers, PCR-Restriction fragment length polymorphism (RFLP), PCRRFLP in which ITS1-ITS4 products cut by Msp I ve Bln I restriction enzymes] for the identification of Candida species revealed that CHROMagar Candida medium combined with API ID 32C kit yielded the same results (100% compatible) as molecular techniques for the species identification of Candida isolates. Since these phenotypic methods were simple and cost effective when compared to molecular techniques, they should be considered in the identification of Candida species.

Emerging multidrug-resistant Candida duobushaemulonii infections in Panama hospitals: importance of laboratory surveillance and accurate identification.

PubMed

Ramos, Ruben; Caceres, Diego H; Perez, Marilyn; Garcia, Nicole; Castillo, Wendy; Santiago, Erika; Borace, Jovanna; Lockhart, Shawn R; Berkow, Elizabeth L; Hayer, Lizbeth; Espinosa-Bode, Andres; Moreno, Jose; Jackson, Brendan R; Moran, Jackeline; Chiller, Tom; de Villarreal, Gloriela; Sosa, Nestor; Vallabhaneni, Snigdha

2018-04-25

Candida duobushaemulonii , a yeast closely related to Candida auris, is thought to rarely cause infections, and is often misidentified. In October 2016, the Panamanian Ministry of Health implemented laboratory surveillance for C. auris Suspected C. auris isolates were forwarded to the national reference laboratory for identification by Matrix Assisted Laser Desorption Ionization-Time of Flight mass spectrometry and antifungal susceptibility testing. During November 2016-May 2017, 17 of 36 (47%) isolates suspected to be C. auris were identified as C. duobushaemulonii. These 17 isolates were obtained from 14 patients at six hospitals. Ten patients, including three children, had bloodstream infections, MICs for fluconazole, voriconazole, and amphotericin B were elevated. No resistance to echinocandins was observed. C. duobushaemulonii causes more invasive infections than previously appreciated, and poses a substantial problem given it is resistant to multiple antifungals. Expanded laboratory surveillance is an important step in the detection and control of such emerging pathogens. Copyright © 2018 American Society for Microbiology.

Thionin-like peptide from Capsicum annuum fruits: mechanism of action and synergism with fluconazole against Candida species.

PubMed

Taveira, Gabriel B; Carvalho, André O; Rodrigues, Rosana; Trindade, Fernanda G; Da Cunha, Maura; Gomes, Valdirene M

2016-01-27

Thionins are a family of plant antimicrobial peptides (AMPs), which participate in plant defense system against pathogens. Here we describe some aspects of the CaThi thionin-like action mechanism, previously isolated from Capsicum annuum fruits. Thionin-like peptide was submitted to antimicrobial activity assays against Candida species for IC50 determination and synergism with fluconazole evaluation. Viability and plasma membrane permeabilization assays, induction of intracellular ROS production analysis and CaThi localization in yeast cells were also investigated. CaThi had strong antimicrobial activity against six tested pathogenic Candida species, with IC50 ranging from 10 to 40 μg.mL(-1). CaThi antimicrobial activity on Candida species was candidacidal. Moreover, CaThi caused plasma membrane permeabilization in all yeasts tested and induces oxidative stresses only in Candida tropicalis. CaThi was intracellularly localized in C. albicans and C. tropicalis, however localized in nuclei in C. tropicalis, suggesting a possible nuclear target. CaThi performed synergistically with fluconazole inhibiting all tested yeasts, reaching 100% inhibition in C. parapsilosis. The inhibiting concentrations for the synergic pair ranged from 1.3 to 4.0 times below CaThi IC50 and from zero to 2.0 times below fluconazole IC50. The results reported herein may ultimately contribute to future efforts aiming to employ this plant-derived AMP as a new therapeutic substance against yeasts.

Assessment of herbal drugs for promising anti-Candida activity.

PubMed

Soliman, Sameh S M; Semreen, Mohammad H; El-Keblawy, Ali A; Abdullah, Arbab; Uppuluri, Priya; Ibrahim, Ashraf S

2017-05-08

Microbial infections are diverse and cause serious human diseases. Candida albicans infections are serious healthcare-related infections that are complicated by its morphological switching from yeast to hyphae, resistant biofilm formation and mixed infections with bacteria. Due to the increase in drug resistance to currently used antimicrobial agents and the presence of undesirable side effects, the need for safe and effective novel therapies is important. Compounds derived from plants are known for their medicinal properties including antimicrobial activities. The purpose of the study was to compare and evaluate the anti-Candida activities of several medicinal plants in order for the selection of a herbal drug for human use as effective antimicrobial. The selection was taking into considerations two important parameters; parameters related to the selected drug including activity, stability, solubility and toxicity and parameters related to the pathogen including its different dynamic growth and its accompanied secondary bacterial infections. Seven different plants including Avicennia marina (Qurm), Fagonia indica (Shoka'a), Lawsania inermis (Henna), Portulaca oleracea (Baq'lah), Salvadora persica (Souwak), Ziziphus spina- Christi (Sidr) and Asphodelus tenuifolius (Kufer) were ground and extracted with ethanol. The ethanol extracts were evaporated and the residual extract dissolved in water prior to testing against Candida albicans in its different morphologies. The antibacterial and cytotoxic effects of the plants extracts were also tested. Out of the seven tested plants, L. inermis and P. oleracea showed significant anti-Candida activity with MIC ~10 μg/mL. Furthermore, both plant extracts were able to inhibit C. albicans growth at its dynamic growth phases including biofilm formation and age resistance. Accompanied secondary bacterial infections can complicate Candida pathogenesis. L. inermis and P. oleracea extracts showed effective antibacterial activities against S. aureus, P. aeruginosa, E. coli, and the multidrug resistant (MDR) A. baumannii and Klebsiella pneumoniae. Both extracts showed no toxicity when measured at their MIC on human erythrocytes. The results from this study suggested that L. inermis and P. oleracea extracts and/or their chemicals are likely to be promising drugs for human use against C. albicans and MDR bacteria.

The effect of Zuccagnia punctata, an Argentine medicinal plant, on virulence factors from candida species.

PubMed

Gabriela, Nuño; Rosa, Alberto María; Catiana, Zampini Iris; Soledad, Cuello; Mabel, Ordoñez Roxana; Esteban, Sayago Jorge; Veronica, Baroni; Daniel, Wunderlin; Ines, Isla María

2014-07-01

Zuccagnia punctata Cav. has been used as a traditional medicine in Argentina for the treatment of bacterial and fungal infections. In this study, we evaluated the ability of Z. punctata extract (ZpE) and compounds isolated from it to inhibit the growth and virulence factors of Candida species. ZpE showed inhibitory activity against planktonic cells of all assayed Candida species with MIC values of 400 microg/mL and with MFC values between 400 and 1,200 microg/mL. The principal identified compounds by HPLC-MS/MS and UV-VIS were chalcones (2',4'-dihydroxy-3'-methoxychalcone, 2',4'- dihydroxychalcone), flavones (galangin, 3,7-dihydroxyflavone and chrysin) and flavanones (naringenin, 7-hydroxyflavanone and pinocembrine). These compounds were more effective as inhibitors than the extracts upon biofilm formation as well as on preformed Candida biofilm and yeast germ tube formation. Furthermore, ZpE and chalcones are able to inhibit exoenzymes, which are responsible for the invasion mechanisms of the pathogens. All these effects could moderate colonization, thereby suppressing the pathogen invasive potential. Our results indicate that ZpE and chalcones could be used in antifungal therapy.

Sequence and Analysis of the Genome of the Pathogenic Yeast Candida orthopsilosis

PubMed Central

Riccombeni, Alessandro; Vidanes, Genevieve; Proux-Wéra, Estelle; Wolfe, Kenneth H.; Butler, Geraldine

2012-01-01

Candida orthopsilosis is closely related to the fungal pathogen Candida parapsilosis. However, whereas C. parapsilosis is a major cause of disease in immunosuppressed individuals and in premature neonates, C. orthopsilosis is more rarely associated with infection. We sequenced the C. orthopsilosis genome to facilitate the identification of genes associated with virulence. Here, we report the de novo assembly and annotation of the genome of a Type 2 isolate of C. orthopsilosis. The sequence was obtained by combining data from next generation sequencing (454 Life Sciences and Illumina) with paired-end Sanger reads from a fosmid library. The final assembly contains 12.6 Mb on 8 chromosomes. The genome was annotated using an automated pipeline based on comparative analysis of genomes of Candida species, together with manual identification of introns. We identified 5700 protein-coding genes in C. orthopsilosis, of which 5570 have an ortholog in C. parapsilosis. The time of divergence between C. orthopsilosis and C. parapsilosis is estimated to be twice as great as that between Candida albicans and Candida dubliniensis. There has been an expansion of the Hyr/Iff family of cell wall genes and the JEN family of monocarboxylic transporters in C. parapsilosis relative to C. orthopsilosis. We identified one gene from a Maltose/Galactoside O-acetyltransferase family that originated by horizontal gene transfer from a bacterium to the common ancestor of C. orthopsilosis and C. parapsilosis. We report that TFB3, a component of the general transcription factor TFIIH, undergoes alternative splicing by intron retention in multiple Candida species. We also show that an intein in the vacuolar ATPase gene VMA1 is present in C. orthopsilosis but not C. parapsilosis, and has a patchy distribution in Candida species. Our results suggest that the difference in virulence between C. parapsilosis and C. orthopsilosis may be associated with expansion of gene families. PMID:22563396

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

Central Role for Dermal Fibroblasts in Skin Model Protection against Candida albicans.

PubMed

Kühbacher, Andreas; Henkel, Helena; Stevens, Philip; Grumaz, Christian; Finkelmeier, Doris; Burger-Kentischer, Anke; Sohn, Kai; Rupp, Steffen

2017-06-01

The fungal pathogen Candida albicans colonizes basically all human epithelial surfaces, including the skin. Under certain conditions, such as immunosuppression, invasion of the epithelia occurs. Not much is known about defense mechanisms against C. albicans in subepithelial layers such as the dermis. Using immune cell-supplemented 3D skin models we defined a new role for fibroblasts in the dermis and identified a minimal set of cell types for skin protection against C. albicans invasion. Dual RNA sequencing of individual host cell populations and C. albicans revealed that dermal invasion is directly impeded by dermal fibroblasts. They are able to integrate signals from the pathogen and CD4+ T cells and shift toward an antimicrobial phenotype with broad specificity that is dependent on Toll-like receptor 2 and interleukin 1β. These results highlight a central function of dermal fibroblasts for skin protection, opening new possibilities for treatment of infectious diseases. © 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 and antimicrobial properties of 3-aryl-1-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-yl)propanes as 'carba-analogues' of the N-arylmethyl-N-[(1,1'-biphenyl)-4-ylmethyl])-1H-imidazol-1-amines, a new class of antifungal agents.

PubMed

Castellano, Sabrina; Stefancich, Giorgio; Chillotti, Annalisa; Poni, Graziella

2003-08-01

A new series of 3-phenyl-1-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-yl)propane derivatives 2a-l (related to the antifungal bifonazole) was synthesized and tested for antimicrobial activity. A number of substituents on the phenyl ring were chosen to compare the relative biological properties with those of corresponding aza-analogues, previously described by us. The in vitro antifungal activities of the newly synthesized azoles were tested against several pathogenic fungi responsible for human disease. Test pathogens included representatives of yeasts (Candida albicans, Candida parapsilosis, Criptococcus neoformans), dermathophytes (Tricophyton verrucosum, Tricophyton rubrum, Microsporum gypseum) and moulds (Aspergillus fumigatus). Bifonazole and miconazole were used as reference drugs. Title compounds were prepared by alkylation of 1-biphenyl-4-yl-2-imidazol-1-yl-ethanone with the proper arylmethyl halide and subsequent reduction of corresponding ketones applying the Huang-Minlon modification of the Wolff-Kishner reaction.

Elevated Chitin Content Reduces the Susceptibility of Candida Species to Caspofungin

PubMed Central

Walker, Louise A.; Gow, Neil A. R.

2013-01-01

The echinocandin antifungal drugs inhibit synthesis of the major fungal cell wall polysaccharide β(1,3)-glucan. Echinocandins have good efficacy against Candida albicans but reduced activity against other Candida species, in particular Candida parapsilosis and Candida guilliermondii. Treatment of Candida albicans with a sub-MIC level of caspofungin has been reported to cause a compensatory increase in chitin content and to select for sporadic echinocandin-resistant FKS1 point mutants that also have elevated cell wall chitin. Here we show that elevated chitin in response to caspofungin is a common response in various Candida species. Activation of chitin synthesis was observed in isolates of C. albicans, Candida tropicalis, C. parapsilosis, and C. guilliermondii and in some isolates of Candida krusei in response to caspofungin treatment. However, Candida glabrata isolates demonstrated no exposure-induced change in chitin content. Furthermore, isolates of C. albicans, C. krusei, C. parapsilosis, and C. guilliermondii which were stimulated to have higher chitin levels via activation of the calcineurin and protein kinase C (PKC) signaling pathways had reduced susceptibility to caspofungin. Isolates containing point mutations in the FKS1 gene generally had higher chitin levels and did not demonstrate a further compensatory increase in chitin content in response to caspofungin treatment. These results highlight the potential of increased chitin synthesis as a potential mechanism of tolerance to caspofungin for the major pathogenic Candida species. PMID:23089748

Effect of serine-type protease of Candida spp. isolated from linear gingival erythema of HIV-positive children: critical factors in the colonization.

PubMed

Portela, Maristela B; Souza, Ivete P R; Abreu, Celina M; Bertolini, Martinna; Holandino, Carla; Alviano, Celuta S; Santos, André L S; Soares, Rosangela M A

2010-11-01

  There are several kinds of oral soft tissue lesions that are common manifestations observed in human immunodeficiency virus (HIV)-infected children; for example, linear gingival erythema (LGE) that is a distinctive fiery red band along the margin of the gingivae. The etiology and pathogenesis of LGE are questionable, but a candidal origin has been suggested. Proteases are key virulence attributes produced by a variety of pathogenic fungi, including Candida. The objective of the present study is to identify the protease production in Candida species including, C. albicans (n=5), C. dubliniensis (n=1) and C. tropicalis (n=1), isolated directly from typical LGE lesions observed in six HIV-positive children, and also to test the effect of a serine protease inhibitor on the interaction of Candida spp. and epithelial cells in vitro. The ability of Candida strains to release proteases in the culture supernatant fluids was visualized by gelatin-SDS-PAGE. Gel strips containing 30-fold concentrated supernatant (1.5×10(8) yeasts) were incubated at 37°C for 48 h in 50 mM sodium phosphate buffer, pH 5.5. The concentrated supernatants were also incubated with fibronectin, laminin, immunoglobulin G, bovine serum albumin and human serum albumin. The effect of serine protease inhibitor on the interaction of Candida spp. and epithelial cells (MA 104) was measured after pre-treatment of fungi with the inhibitor (phenylmethylsulphonyl fluoride, PMSF). All the extracellular proteases were completely inhibited by PMSF, identifying these activities as serine-type proteases. Interestingly, a common 62-kDa serine protease was observed in all Candida strains. The culture supernatants, rich in serine protease activities, cleaved several soluble proteinaceous substrates. Additionally, we demonstrated that pre-treatment of C. albicans, C. dubliniensis and C. tropicalis with PMSF diminished the interaction with epithelial cells. Collectively, our results show that Candida spp. isolated from LGE lesions produced and secreted serine proteases and these enzymes may be involved in the initial colonization events. © 2010 John Wiley & Sons A/S.

Selected Essential Oils as Antifungal Agents Against Antibiotic-Resistant Candida spp.: In Vitro Study on Clinical and Food-Borne Isolates.

PubMed

Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina; Maroszyńska, Marta

2017-01-01

Candida spp. cause significant health problems, inducing various types of superficial and deep-seated mycoses in humans. As a result of the increasing antibiotic resistance among pathogenic yeasts, the interest in alternative agents of antifungal activity is growing. This study evaluated the antimicrobial activity of selected essential oils (EOs) against Candida clinical and food-borne strains, including antibiotic-resistant isolates, in relation to yeast cell surface hydrophobicity (CSH). Candida strains showed different range of susceptibility to tea tree, thyme, peppermint, and clove oils, and peppermint oil demonstrated the lowest anticandidal activity with minimal inhibitory concentrations (MICs) of 0.03-8.0% v/v. MIC values for thyme and clove oils ranged from 0.03% to 0.25% v/v, and for tea tree oil-from 0.12% to 2.0% v/v. The exception was Candida tropicalis food-borne strain, the growth of which was inhibited after application of EOs at concentration of 8% v/v. Due to diverse yeast susceptibility to EOs, isolates were divided into five clusters in a principal component analysis model, each containing both clinical and food-borne strains. Hydrophobic properties of yeast were also diversified, and 37% of clinical and 50% of food-borne strains exhibited high hydrophobicity. The study indicates high homology of clinical and food-borne Candida isolates in relation to their susceptibility to anticandidal agents and hydrophobic properties. The susceptibility of yeasts to EOs could be partially related to their CSH. High antifungal activity of examined EOs, also against antibiotic-resistant isolates, indicates their usefulness as agents preventing the development of Candida strains of different origin.

Detection of Candida species in pregnant Chinese women with a molecular beacon method.

PubMed

Zhai, Yanhong; Liu, Jing; Zhou, Li; Ji, Tongzhen; Meng, Lingxin; Gao, Yang; Liu, Ran; Wang, Xiao; Li, Lin; Lu, Binghuai; Cao, Zheng

2018-04-20

Candida pathogens are commonly found in women and can cause vulvovaginal candidiasis (VVC), whose infection rate is further increased during pregnancy. We aimed to study the Candida prevalence and strain distribution in pregnant Chinese women with a molecular beacon assay. From March 2016 to February 2017, a total of 993 pregnant women attending routine antenatal visits at the Beijing Obstetrics and Gynecology Hospital were enrolled. For Candida detection and identification, a unique molecular beacon assay was presented and compared with a traditional phenotypic method. Antifungal susceptibility was tested with the following agents: 5-flucytosine, amphotericin B, fluconazole, itraconazole and voriconazole. The prevalence of Candida was found to be 21.8 % when using the molecular method and 15.0 % when using the phenotypic method. The distribution of the Candida spp. was listed in order of decreasing prevalence: Candida albicans (79.8 %), Candida glabrata (13.5 %), Candida parapsilosis (3.7 %), Candida krusei (2.2 %) and Candida tropicalis (1.1 %). We found that 90.7 % of the Candida detection results were consistent between the molecular and the phenotypic methods. In the cases where the sequencing analyses for the Candida isolates resulted in inconsistent identification, the molecular method showed higher sensitivity than the phenotypic method (96.0 vs 64.6 %). C. albicans, C. glabrata and C. parapsilosis were essentially susceptible to all five antifungal agents tested, whereas C. tropicalis and C. krusei were susceptible to voriconazole and amphotericin B. By exhibiting good sensitivity and specificity, the molecular assay may offer a fast and accurate Candida screening platform for pregnant women.

Antimicrobial potential of 27 plants consumed by chimpanzees (Pan troglodytes verus Blumenbach) in Ivory Coast.

PubMed

Ahoua, Angora Rémi Constant; Konan, Amoin Georgette; Bonfoh, Bassirou; Koné, Mamidou Witabouna

2015-10-23

Due to their genetic proximity, chimpanzees share with human several diseases including bacterial, fungal and viral infections, such as candidiasis, acquired immune deficiency syndrome (AIDS), Ebola virus disease. However, in its natural environment, chimpanzees are tolerant to several pathogens including simian immunodeficiency virus (SIV), virus related to human immunodeficiency virus (HIV) that contribute to the emergence of opportunistic diseases such as microbial infections. Twenty seven species of plants consumed by chimpanzees were evaluated for their antimicrobial potential against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, Candida tropicalis and Candida glabrata using the agar diffusion technique and micro-dilution in 96-well plates. In total 132 extracts (33 dichloromethane, 33 methanol, 33 ethyl acetate and 33 aqueous) were tested. The results showed that 24 extracts (18 %) showed activity against bacteria and 6 extracts (5 %) were active against yeasts. The minimal inhibitory concentrations (MICs) values of active extracts ranged between 23 and 750 μg/ml for bacteria and between 188 and 1500 μg/ml for yeasts. Tristemma coronatum was the most promising on the studied microorganisms followed by Beilschmiedia mannii. The extracts of the two plants indicated by chimpanzees have potential for antimicrobial use in human.

Lactate signalling regulates fungal β-glucan masking and immune evasion

PubMed Central

Ballou, Elizabeth R.; Avelar, Gabriela M.; Childers, Delma S.; Mackie, Joanna; Bain, Judith M.; Wagener, Jeanette; Kastora, Stavroula L.; Panea, Mirela D.; Hardison, Sarah E.; Walker, Louise A.; Erwig, Lars P.; Munro, Carol A.; Gow, Neil A.R.; Brown, Gordon D.; MacCallum, Donna M.; Brown, Alistair J.P.

2017-01-01

Summary Paragraph As they proliferate, fungi expose antigens at their cell surface that are potent stimulators of the innate immune response, and yet the commensal fungus Candida albicans is able to colonize immuno-competent individuals. We show that C. albicans may evade immune detection by presenting a moving immunological target. We report that the exposure of β-glucan, a key Pathogen Associated Molecular Pattern (PAMP) located at the cell surface of C. albicans and other pathogenic Candida species, is modulated in response to changes in carbon source. Exposure to lactate induces β-glucan masking in C. albicans via a signaling pathway that has recruited an evolutionarily conserved receptor (Gpr1) and transcriptional factor (Crz1) from other well-characterized pathways. In response to lactate, these regulators control the expression of cell wall related genes that contribute to β-glucan masking. This represents the first description of active PAMP masking by a Candida species, a process that reduces the visibility of the fungus to the immune system. PMID:27941860

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

Uncommon opportunistic fungal infections of oral cavity: A review

PubMed Central

Deepa, AG; Nair, Bindu J; Sivakumar, TT; Joseph, Anna P

2014-01-01

The majority of opportunistic oral mucosal fungal infections are due to Candida albicans and Aspergillus fumigatus species. Mucor and Cryptococcus also have a major role in causing oral infections, whereas Geotrichum, Fusarium, Rhodotorula, Saccharomyces and Penicillium marneffei are uncommon pathogens in the oral cavity. The broad spectrum of clinical presentation includes pseudo-membranes, abscesses, ulcers, pustules and extensive tissue necrosis involving bone. This review discusses various uncommon opportunistic fungal infections affecting the oral cavity including their morphology, clinical features and diagnostic methods. PMID:25328305

Outcomes and risk factors for cancer patients undergoing endoscopic intervention of malignant biliary obstruction.

PubMed

Haag, Georg-Martin; Herrmann, Thomas; Jaeger, Dirk; Stremmel, Wolfgang; Schemmer, Peter; Sauer, Peter; Gotthardt, Daniel Nils

2015-12-04

Malignant bile duct obstruction is a common problem among cancer patients with hepatic or lymphatic metastases. Endoscopic retrograde cholangiography (ERC) with the placement of a stent is the method of choice to improve biliary flow. Only little data exist concerning the outcome of patients with malignant biliary obstruction in relationship to microbial isolates from bile. Bile samples were taken during the ERC procedure in tumor patients with biliary obstruction. Clinical data including laboratory values, tumor-specific treatment and outcome data were prospectively collected. 206 ERC interventions in 163 patients were recorded. In 43 % of the patients, systemic treatment was (re-) initiated after successful biliary drainage. A variety of bacteria and fungi was detected in the bile samples. One-year survival was significantly worse in patients from whom multiresistant pathogens were isolated than in patients, in whom other species were detected. Increased levels of inflammatory markers were associated with a poor one-year survival. The negative impact of these two factors was confirmed in multivariate analysis. In patients with pancreatic cancer, univariate analysis showed a negative impact on one-year survival in case of detection of Candida species in the bile. Multivariate analysis confirmed the negative prognostic impact of Candida in the bile in pancreatic cancer patients. Outcome in tumor patients with malignant bile obstruction is associated with the type of microbial biliary colonization. The proof of multiresistant pathogens or Candida, as well as the level of inflammation markers, have an impact on the prognosis of the underlying tumor disease.

Synthesis, antimicrobial evaluation and theoretical prediction of NMR chemical shifts of thiazole and selenazole derivatives with high antifungal activity against Candida spp.

NASA Astrophysics Data System (ADS)

Łączkowski, Krzysztof Z.; Motylewska, Katarzyna; Baranowska-Łączkowska, Angelika; Biernasiuk, Anna; Misiura, Konrad; Malm, Anna; Fernández, Berta

2016-03-01

Synthesis and investigation of antimicrobial activities of novel thiazoles and selenazoles is presented. Their structures were determined using NMR, FAB(+)-MS, HRMS and elemental analyses. To support the experiment, theoretical calculations of the 1H NMR shifts were carried out for representative systems within the DFT B3LYP/6-311++G** approximation which additionally confirmed the structure of investigated compounds. Among the derivatives, compounds 4b, 4h, 4j and 4l had very strong activity against reference strains of Candida albicans ATCC and Candida parapsilosis ATCC 22019 with MIC = 0.49-7.81 μg/ml. In the case of compounds 4b, 4c, 4h - 4j and 4l, the activity was very strong against of Candida spp. isolated from clinical materials, i.e. C. albicans, Candida krusei, Candida inconspicua, Candida famata, Candida lusitaniae, Candida sake, C. parapsilosis and Candida dubliniensis with MIC = 0.24-15.62 μg/ml. The activity of several of these was similar to the activity of commonly used antifungal agent fluconazole. Additionally, compounds 4m - 4s were found to be active against Gram-positive bacteria, both pathogenic staphylococci Staphylococcus aureus ATCC with MIC = 31.25-125 μg/ml and opportunistic bacteria, such as Staphylococcus epidermidis ATCC 12228 and Micrococcus luteus ATCC 10240 with MIC = 7.81-31.25 μg/ml.

Increased filamentous growth of Candida albicans in simulated microgravity.

PubMed

Altenburg, Sara D; Nielsen-Preiss, Sheila M; Hyman, Linda E

2008-03-01

Knowledge of simulated microgravity (SMG)-induced changes in the pathogenicity of microorganisms is important for success of long-term spaceflight. In a previous study using the high aspect ratio vessel bioreactor, we showed that the yeast species Saccharomyces cerevisiae underwent a significant phenotypic response when grown in modeled microgravity, which was reflected in the analysis of gene expression profiles. In this study, we establish that Candida albicans responds to SMG in a similar fashion, demonstrating that there is a conserved response among yeast to this environmental stress. We also report that the growth of C. albicans in SMG results in a morphogenic switch that is consistent with enhanced pathogenicity. Specifically, we observed an increase in filamentous forms of the organism and accompanying changes in the expression of two genes associated with the yeast-hyphal transition. The morphological response may have significant implications for astronauts' safety, as the fungal pathogen may become more virulent during spaceflight.

Diagnostic value of immunoglobulin G antibodies against Candida enolase and fructose-bisphosphate aldolase for candidemia

PubMed Central

2013-01-01

Background The yeast Candida is one of the most frequent pathogens isolated from bloodstream infections and is associated with significant morbidity and mortality. Problems with clinical and microbiological diagnosis of invasive candidiasis (IC) have prompted the development of non-culture-based laboratory methods. Previous reports suggest that serological detection of antibodies might be useful for diagnosing systemic candidiasis. Methods Diagnosis of IC using antibodies against recombinant Candida albicans enolase (Eno) and fructose-bisphosphate aldolase (Fba1) was evaluated. Using recombinant Eno and Fba1 as coating antigens, enzyme-linked immunosorbent assays (ELISAs) were used to analyze sera from patients with candidemia (n = 101), Candida colonization (n = 50), bacteremia (n = 84), invasive aspergillosis (n = 40); and from healthy controls (n = 200). Results The results demonstrated that ELISA detection of anti-Eno and anti-Fba1 IgG distinguished IC from other pathogenic infections in patients and healthy individuals. The sensitivity, specificity, and positive and negative predictive values were 72.3%, 94.7%, 78.5% and 93% for anti-Eno, and 87.1%, 92.8%, 76.5% and 96.4% for anti-Fba1 antibodies, respectively. Combining these two tests improved sensitivity up to 90.1% and negative predictive value up to 97.1%, with specificity and positive predictive values of 90.6% and 72.2%. The tests were specific to the Candida genus and antibody titers were higher for candidemia patients than for controls. Positive antibody tests were obtained before blood culture results for 42.2% of patients for anti-Eno and 51.1% for anti-Fba1. Conclusion These data suggest that tests that detect IgG antibodies against Candida enolase and fructose-bisphosphate aldolase, especially when used in combination, could be a powerful tool for diagnosing IC. PMID:23725337

Diagnostic value of immunoglobulin G antibodies against Candida enolase and fructose-bisphosphate aldolase for candidemia.

PubMed

Li, Fang-Qiu; Ma, Chun-Fang; Shi, Li-Ning; Lu, Jing-Fen; Wang, Ying; Huang, Mei; Kong, Qian-Qian

2013-05-31

The yeast Candida is one of the most frequent pathogens isolated from bloodstream infections and is associated with significant morbidity and mortality. Problems with clinical and microbiological diagnosis of invasive candidiasis (IC) have prompted the development of non-culture-based laboratory methods. Previous reports suggest that serological detection of antibodies might be useful for diagnosing systemic candidiasis. Diagnosis of IC using antibodies against recombinant Candida albicans enolase (Eno) and fructose-bisphosphate aldolase (Fba1) was evaluated. Using recombinant Eno and Fba1 as coating antigens, enzyme-linked immunosorbent assays (ELISAs) were used to analyze sera from patients with candidemia (n = 101), Candida colonization (n = 50), bacteremia (n = 84), invasive aspergillosis (n = 40); and from healthy controls (n = 200). The results demonstrated that ELISA detection of anti-Eno and anti-Fba1 IgG distinguished IC from other pathogenic infections in patients and healthy individuals. The sensitivity, specificity, and positive and negative predictive values were 72.3%, 94.7%, 78.5% and 93% for anti-Eno, and 87.1%, 92.8%, 76.5% and 96.4% for anti-Fba1 antibodies, respectively. Combining these two tests improved sensitivity up to 90.1% and negative predictive value up to 97.1%, with specificity and positive predictive values of 90.6% and 72.2%. The tests were specific to the Candida genus and antibody titers were higher for candidemia patients than for controls. Positive antibody tests were obtained before blood culture results for 42.2% of patients for anti-Eno and 51.1% for anti-Fba1. These data suggest that tests that detect IgG antibodies against Candida enolase and fructose-bisphosphate aldolase, especially when used in combination, could be a powerful tool for diagnosing IC.

Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology.

PubMed

Zhao, Ying; Tsang, Chi-Ching; Xiao, Meng; Cheng, Jingwei; Xu, Yingchun; Lau, Susanna K P; Woo, Patrick C Y

2015-10-22

Internal transcribed spacer region (ITS) sequencing is the most extensively used technology for accurate molecular identification of fungal pathogens in clinical microbiology laboratories. Intra-genomic ITS sequence heterogeneity, which makes fungal identification based on direct sequencing of PCR products difficult, has rarely been reported in pathogenic fungi. During the process of performing ITS sequencing on 71 yeast strains isolated from various clinical specimens, direct sequencing of the PCR products showed ambiguous sequences in six of them. After cloning the PCR products into plasmids for sequencing, interpretable sequencing electropherograms could be obtained. For each of the six isolates, 10-49 clones were selected for sequencing and two to seven intra-genomic ITS copies were detected. The identities of these six isolates were confirmed to be Candida glabrata (n=2), Pichia (Candida) norvegensis (n=2), Candida tropicalis (n=1) and Saccharomyces cerevisiae (n=1). Multiple sequence alignment revealed that one to four intra-genomic ITS polymorphic sites were present in the six isolates, and all these polymorphic sites were located in the ITS1 and/or ITS2 regions. We report and describe the first evidence of intra-genomic ITS sequence heterogeneity in four different pathogenic yeasts, which occurred exclusively in the ITS1 and ITS2 spacer regions for the six isolates in this study.

Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology

PubMed Central

Zhao, Ying; Tsang, Chi-Ching; Xiao, Meng; Cheng, Jingwei; Xu, Yingchun; Lau, Susanna K. P.; Woo, Patrick C. Y.

2015-01-01

Internal transcribed spacer region (ITS) sequencing is the most extensively used technology for accurate molecular identification of fungal pathogens in clinical microbiology laboratories. Intra-genomic ITS sequence heterogeneity, which makes fungal identification based on direct sequencing of PCR products difficult, has rarely been reported in pathogenic fungi. During the process of performing ITS sequencing on 71 yeast strains isolated from various clinical specimens, direct sequencing of the PCR products showed ambiguous sequences in six of them. After cloning the PCR products into plasmids for sequencing, interpretable sequencing electropherograms could be obtained. For each of the six isolates, 10–49 clones were selected for sequencing and two to seven intra-genomic ITS copies were detected. The identities of these six isolates were confirmed to be Candida glabrata (n = 2), Pichia (Candida) norvegensis (n = 2), Candida tropicalis (n = 1) and Saccharomyces cerevisiae (n = 1). Multiple sequence alignment revealed that one to four intra-genomic ITS polymorphic sites were present in the six isolates, and all these polymorphic sites were located in the ITS1 and/or ITS2 regions. We report and describe the first evidence of intra-genomic ITS sequence heterogeneity in four different pathogenic yeasts, which occurred exclusively in the ITS1 and ITS2 spacer regions for the six isolates in this study. PMID:26506340

DETECTION AND IDENTIFICATION OF PATHOGENIC CANDIDA SPECIES IN WATER USING FLOW CYTOMETRY COUPLED WITH TAQMAN PCR

EPA Science Inventory

As the incidence of human fungal infection increases, the ability to detect and identify pathogenic fungi in potential environmental reservoirs becomes increasingly important for disease control. PCR based assays are widely used for diagnostic purposes, but may be inadequate for...

Molecular mechanisms of mucocutaneous immunity against Candida and Staphylococcus species.

PubMed

Maródi, László; Cypowyj, Sophie; Tóth, Beáta; Chernyshova, Liudmyla; Puel, Anne; Casanova, Jean-Laurent

2012-11-01

Signal transducer and activator of transcription (STAT) proteins are key components of the innate and adaptive immune responses to pathogenic microorganisms. Recent research on primary immunodeficiency disorders and the identification of patients carrying germline mutations in STAT1, STAT3, and STAT5B have highlighted the role of human STATs in host defense against various viruses, bacteria, and fungi. Mutations in STAT1 and STAT3 disrupt various cytokine pathways that control mucocutaneous immunity against Candida species, especially Candida albicans, and Staphylococcus species, especially Staphylococcus aureus. Here we consider inborn errors of immunity arising from mutations in either STAT1 or STAT3 that affect mucocutaneous immunity to Candida and Staphylococcus species. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Interplay between Candida albicans and the Mammalian Innate Host Defense

PubMed Central

Cheng, Shih-Chin; Joosten, Leo A. B.; Kullberg, Bart-Jan

2012-01-01

Candida albicans is both the most common fungal commensal microorganism in healthy individuals and the major fungal pathogen causing high mortality in at-risk populations, especially immunocompromised patients. In this review, we summarize the interplay between the host innate system and C. albicans, ranging from how the host recognizes, responds, and clears C. albicans infection to how C. albicans evades, dampens, and escapes from host innate immunity. PMID:22252867

Looking into Candida albicans infection, host response, and antifungal strategies.

PubMed

Wang, Yan

2015-01-01

Candida albicans, a commonly encountered fungal pathogen, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. Among the virulence traits of C. albicans, yeast-to-hypha transition is most widely acknowledged. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs), and defence against C. albicans infection is provided by an exquisite interplay between the innate and adaptive arms of the host immune system.

The crystal structure of the secreted aspartic protease 1 from Candida parapsilosis in complex with pepstatin A

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

Dostál, Jiří; Brynda, Jiří; Hrušková-Heidingsfeldová, Olga

2010-09-01

Opportunistic pathogens of the genus Candida cause infections representing a major threat to long-term survival of immunocompromised patients. Virulence of the Candida pathogens is enhanced by production of extracellular proteolytic enzymes and secreted aspartic proteases (Saps) are therefore studied as potential virulence factors and possible targets for therapeutic drug design. Candida parapsilosis is less invasive than C. albicans, however, it is one of the leading causative agents of yeast infections. We report three-dimensional crystal structure of Sapp1p from C. parapsilosis in complex with pepstatin A, the classical inhibitor of aspartic proteases. The structure of Sapp1p was determined from protein isolatedmore » from its natural source and represents the first structure of Sap from C. parapsilosis. Overall fold and topology of Sapp1p is very similar to the archetypic fold of monomeric aspartic protease family and known structures of Sap isoenzymes from C. albicans and Sapt1p from C. tropicalis. Structural comparison revealed noticeable differences in the structure of loops surrounding the active site. This resulted in differential character, shape, and size of the substrate binding site explaining divergent substrate specificities and inhibitor affinities. Determination of structures of Sap isoenzymes from various species might contribute to the development of new Sap-specific inhibitors.« less

Comparative molecular dynamics studies of heterozygous open reading frames of DNA polymerase eta (η) in pathogenic yeast Candida albicans

NASA Astrophysics Data System (ADS)

Satpati, Suresh; Manohar, Kodavati; Acharya, Narottam; Dixit, Anshuman

2017-01-01

Genomic instability in Candida albicans is believed to play a crucial role in fungal pathogenesis. DNA polymerases contribute significantly to stability of any genome. Although Candida Genome database predicts presence of S. cerevisiae DNA polymerase orthologs; functional and structural characterizations of Candida DNA polymerases are still unexplored. DNA polymerase eta (Polη) is unique as it promotes efficient bypass of cyclobutane pyrimidine dimers. Interestingly, C. albicans is heterozygous in carrying two Polη genes and the nucleotide substitutions were found only in the ORFs. As allelic differences often result in functional differences of the encoded proteins, comparative analyses of structural models and molecular dynamic simulations were performed to characterize these orthologs of DNA Polη. Overall structures of both the ORFs remain conserved except subtle differences in the palm and PAD domains. The complementation analysis showed that both the ORFs equally suppressed UV sensitivity of yeast rad30 deletion strain. Our study has predicted two novel molecular interactions, a highly conserved molecular tetrad of salt bridges and a series of π-π interactions spanning from thumb to PAD. This study suggests these ORFs as the homologues of yeast Polη, and due to its heterogeneity in C. albicans they may play a significant role in pathogenicity.

Breakpoints for antifungal agents: an update from EUCAST focussing on echinocandins against Candida spp. and triazoles against Aspergillus spp.

PubMed

Arendrup, Maiken C; Cuenca-Estrella, Manuel; Lass-Flörl, Cornelia; Hope, William W

2013-12-01

Candida and Aspergillus infections have emerged as significant pathogens in recent decades. During this same time, broad spectrum triazole and echinocandin antifungal agents have been developed and increasingly used. One consequence of widespread use is leading to the emergence of mutants with acquired resistance mutations. Therefore, accurate susceptibility testing and appropriate clinical breakpoints for the interpretation of susceptibility results have become increasingly important. Here we review the underlying methodology by which breakpoints have been selected by EUCAST (European Committee on Antimicrobial Susceptibility Testing). Five parameters are evaluated: dosing regimens used; EUCAST MIC distributions from multiple laboratories, species and compound specific epidemiological cut off values (upper MIC limits of wild type isolates or ECOFFs), pharmacokinetic/pharmacodynamic relationships and targets associated with outcome and finally clinical data by species and MIC when available. The general principles are reviewed followed by a detailed review of the individual aspects for Candida species and the three echinocandins and for Aspergillus and the three mould-active azoles. This review provides an update of the subcommittee on antifungal susceptibility testing (AFST) of the EUCAST methodology and summarises the current EUCAST breakpoints for Candida and Aspergillus. Recommendations about applicability of antifungal susceptibility testing in the routine setting are also included. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pseudozyma and other non-Candida opportunistic yeast bloodstream infections in a large stem cell transplant center.

PubMed

Pande, Anupam; Non, Lemuel R; Romee, Rizwan; Santos, Carlos A Q

2017-04-01

Non-Candida opportunistic yeasts are emerging causes of bloodstream infection (BSI) in immunocompromised hosts. However, their clinical presentation, management, and outcomes in stem cell transplant (SCT) recipients are not well described. We report the first case to our knowledge of Pseudozyma BSI in a SCT recipient. He had evidence of cutaneous involvement, which has not been previously described in the literature. He became infected while neutropenic and receiving empiric micafungin, which is notable because Pseudozyma is reported to be resistant to echinocandins. He was successfully treated with the sequential use of liposomal amphotericin B and voriconazole. A review of the literature revealed nine reported instances of Pseudozyma fungemia. We performed a retrospective review of 3557 SCT recipients at our institution from January 2000 to June 2015 and identified four additional cases of non-Candida yeast BSIs. These include two with Cryptococcus, one with Trichosporon, and one with Saccharomyces. Pseudozyma and other non-Candida yeasts are emerging pathogens that can cause severe and disseminated infections in SCT recipients and other immunocompromised hosts. Clinicians should have a high degree of suspicion for echinocandin-resistant yeasts, if patients develop breakthrough yeast BSIs while receiving echinocandin therapy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Novel Candida albicans Transporter Dur31 Is a Multi-Stage Pathogenicity Factor

PubMed Central

Mayer, François L.; Wilson, Duncan; Jacobsen, Ilse D.; Miramón, Pedro; Große, Katharina; Hube, Bernhard

2012-01-01

Candida albicans is the most frequent cause of oral fungal infections. However, the exact pathogenicity mechanisms that this fungus employs are largely unknown and many of the genes expressed during oral infection are uncharacterized. In this study we sought to functionally characterize 12 previously unknown function genes associated with oral candidiasis. We generated homozygous knockout mutants for all 12 genes and analyzed their interaction with human oral epithelium in vitro. Eleven mutants caused significantly less epithelial damage and, of these, deletion of orf19.6656 (DUR31) elicited the strongest reduction in pathogenicity. Interestingly, DUR31 was not only involved in oral epithelial damage, but in multiple stages of candidiasis, including surviving attack by human neutrophils, endothelial damage and virulence in vivo. In silico analysis indicated that DUR31 encodes a sodium/substrate symporter with 13 transmembrane domains and no human homologue. We provide evidence that Dur31 transports histatin 5. This is one of the very first examples of microbial driven import of this highly cytotoxic antimicrobial peptide. Also, in contrast to wild type C. albicans, dur31Δ/Δ was unable to actively increase local environmental pH, suggesting that Dur31 lies in the extracellular alkalinization hyphal auto-induction pathway; and, indeed, DUR31 was required for morphogenesis. In agreement with this observation, dur31Δ/Δ was unable to assimilate the polyamine spermidine. PMID:22438810

Candida species differ in their interactions with immature human gastrointestinal epithelial cells

PubMed Central

Falgier, Christina; Kegley, Sara; Podgorski, Heather; Heisel, Timothy; Storey, Kathleen; Bendel, Catherine M.; Gale, Cheryl A.

2011-01-01

Life-threatening gastrointestinal (GI) diseases of prematurity are highly associated with systemic candidiasis. This implicates the premature GI tract as an important site for invasion by Candida. Invasive interactions of Candida spp. with immature enterocytes have heretofore not been analyzed. Using a primary immature human enterocyte line, we compared the ability of multiple isolates of different Candida spp. to penetrate, injure, and induce a cytokine response from host cells. Of all the Candida spp. analyzed, C. albicans had the greatest ability to penetrate and injure immature enterocytes and to elicit interleukin-8 (IL-8) release (p < 0.01). In addition, C. albicans was the only Candida spp. to form filamentous hyphae when in contact with immature enterocytes. Similarly, a C. albicans mutant with defective hyphal morphogenesis and invasiveness had attenuated cytotoxicity for immature enterocytes (p < 0.003). Thus, hyphal morphogenesis correlates with immature enterocyte penetration, injury and inflammatory responses. Furthermore, variability in enterocyte injury was observed among hyphal-producing C. albicans strains suggesting that individual organism genotypes also influence host-pathogen interactions. Overall, the finding that Candida spp. differed in their interactions with immature enterocytes implicates that individual spp. may employ different pathogenesis mechanisms. PMID:21283049

In vitro inhibitory activities of magnolol against Candida spp.

PubMed

Zhou, Peiru; Fu, Jingya; Hua, Hong; Liu, Xiaosong

2017-01-01

Candida spp. cause various infections involving the skin, mucosa, deep tissues, and even life-threatening candidemia. They are regarded as an important pathogen of nosocomial bloodstream infection, with a high mortality rate. As a result of prolonged exposure to azoles, the therapeutic failure associated with azoles resistance has become a serious challenge in clinical situations. Therefore, novel, alternative antifungals are required urgently. In the present study, the CLSI M-27A broth microdilution method and the 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay were used to evaluate the antifungal effects of magnolol against various standard Candida strains in planktonic mode and biofilm formation, respectively. The antifungal activity of magnolol was demonstrated in planktonic C. albicans and non-albicans Candida species, especially fluconazole-resistant Candida krusei , with the minimum inhibitory concentrations ranging from 10 to 40 μg/mL. The BMIC 90 (minimum concentration with 90% Candida biofilm inhibited) values of magnolol ranged from 20 to 160 μg/mL, whereas the BMIC 90 values of fluconazole were more than 128 μg/mL. As an alternative and broad-spectrum antifungal agent, magnolol might be of benefit to the treatment of refractory Candida infection.

[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.

The Role of IL-17 in Protection against Mucosal Candida Infections

PubMed Central

Mengesha, Bemnet G.; Conti, Heather R.

2017-01-01

Interleukin-17 (IL-17) is a proinflammatory cytokine produced by adaptive CD4+ T helper cells and innate lymphocytes, such as γδ-T cells and TCRβ+ “natural” Th17 cells. IL-17 activates signaling through the IL-17 receptor, which induces other proinflammatory cytokines, antimicrobial peptides and neutrophil chemokines that are important for antifungal activity. The importance of IL-17 in protective antifungal immunity is evident in mice and humans, where various genetic defects related to the IL-17-signaling pathway render them highly susceptible to forms of candidiasis such oropharyngeal candidiasis (OPC) or more broadly chronic mucocutaneous candidiasis (CMC), both caused mainly by the opportunistic fungal pathogen Candida albicans. OPC is common in infants and the elderly, HIV/AIDS and patients receiving chemotherapy and/or radiotherapy for head and neck cancers. This review focuses on the role of IL-17 in protection against candidiasis, and includes a brief discussion of non-Candida albicans fungal infections, as well as how therapeutic interventions blocking IL-17-related components can affect antifungal immunity. PMID:29371568

Molecular analysis of the Candida albicans homolog of Saccharomyces cerevisiae MNN9, required for glycosylation of cell wall mannoproteins.

PubMed

Southard, S B; Specht, C A; Mishra, C; Chen-Weiner, J; Robbins, P W

1999-12-01

The fungal cell wall has generated interest as a potential target for developing antifungal drugs, and the genes encoding glucan and chitin in fungal pathogens have been studied to this end. Mannoproteins, the third major component of the cell wall, contain mannose in either O- or N-glycosidic linkages. Here we describe the molecular analysis of the Candida albicans homolog of Saccharomyces cerevisiae MNN9, a gene required for the synthesis of N-linked outer-chain mannan in yeast, and the phenotypes associated with its disruption. CaMNN9 has significant homology with S. cerevisiae MNN9, including a putative N-terminal transmembrane domain, and represents a member of a similar gene family in Candida. CaMNN9 resides on chromosome 3 and is expressed at similar levels in both yeast and hyphal cells. Disruption of both copies of CaMNN9 leads to phenotypic effects characteristic of cell wall defects including poor growth in liquid media and on solid media, formation of aggregates in liquid culture, osmotic sensitivity, aberrant hyphal formation, and increased sensitivity to lysis after treatment with beta-1,3-glucanase. Like all members of the S. cerevisiae MNN9 gene family the Camnn9Delta strain is resistant to sodium orthovanadate and sensitive to hygromycin B. Analysis of cell wall-associated carbohydrates showed the Camnn9Delta strain to contain half the amount of mannan present in cell walls derived from the wild-type parent strain. Reverse transcription-PCR and Northern analysis of the expression of MNN9 gene family members CaVAN1 and CaANP1 in the Camnn9Delta strain showed that transcription of those genes is not affected in the absence of CaMNN9 transcription. Our results suggest that, while the role MNN9 plays in glycosylation in both Candida and Saccharomyces is conserved, loss of MNN9 function in C. albicans leads to phenotypes that are inconsistent with the pathogenicity of the organism and thus identify CaMnn9p as a potential drug target.

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

Sexual Reproduction of Human Fungal Pathogens

PubMed Central

Heitman, Joseph; Carter, Dee A.; Dyer, Paul S.; Soll, David R.

2014-01-01

We review here recent advances in our understanding of sexual reproduction in fungal pathogens that commonly infect humans, including Candida albicans, Cryptococcus neoformans/gattii, and Aspergillus fumigatus. Where appropriate or relevant, we introduce findings on other species associated with human infections. In particular, we focus on rapid advances involving genetic, genomic, and population genetic approaches that have reshaped our view of how fungal pathogens evolve. Rather than being asexual, mitotic, and largely clonal, as was thought to be prevalent as recently as a decade ago, we now appreciate that the vast majority of pathogenic fungi have retained extant sexual, or parasexual, cycles. In some examples, sexual and parasexual unions of pathogenic fungi involve closely related individuals, generating diversity in the population but with more restricted recombination than expected from fertile, sexual, outcrossing and recombining populations. In other cases, species and isolates participate in global outcrossing populations with the capacity for considerable levels of gene flow. These findings illustrate general principles of eukaryotic pathogen emergence with relevance for other fungi, parasitic eukaryotic pathogens, and both unicellular and multicellular eukaryotic organisms. PMID:25085958

Risk of Vaginal Infections at Early Gestation in Patients with Diabetic Conditions during Pregnancy: A Retrospective Cohort Study.

PubMed

Marschalek, Julian; Farr, Alex; Kiss, Herbert; Hagmann, Michael; Göbl, Christian S; Trofaier, Marie-Louise; Kueronya, Verena; Petricevic, Ljubomir

2016-01-01

Pregnant women with gestational diabetes mellitus (GDM) are reported to be at increased risk for infections of the genital tract. This study aimed to compare the prevalence of asymptomatic bacterial vaginosis (BV) and Candida colonization at early gestation between pregnant women with and without diabetic conditions during pregnancy. We included data from 8, 486 singleton pregnancies that underwent an antenatal infection screen-and-treat programme at our department. All women with GDM or pre-existing diabetes were retrospectively assigned to the diabetic group (DIAB), whereas non-diabetic women served as controls (CON). Prevalence for BV and Candida colonization was 9% and 14% in the DIAB group, and 9% and 13% in the CON group, respectively (n.s.). No significant difference regarding stillbirth and preterm delivery (PTD), defined as a delivery earlier than 37 + 0 (37 weeks plus 0 days) weeks of gestation was found. We could not find an increased risk of colonization with vaginal pathogens at early gestation in pregnant women with diabetes, compared to non-diabetic women. Large prospective studies are needed to evaluate the long-term risk of colonization with vaginal pathogens during the course of pregnancy in these women.

Antibacterial and Antifungal Activity of Essential Oils against Pathogens Responsible for Otitis Externa in Dogs and Cats.

PubMed

Ebani, Valentina V; Nardoni, Simona; Bertelloni, Fabrizio; Najar, Basma; Pistelli, Luisa; Mancianti, Francesca

2017-04-21

Background: Essential oils (EOs) are recommended by some veterinarians to treat otitis externa in pets, but data about their efficacy in scientific literature are very scant. Methods: Nine commercial EOs, from roman chamomile ( Anthemis nobilis L.), star anise ( Illicium verum ), lavender ( Lavandula hybrida ), litsea ( Litsea cubeba (Lour.) Pers.), basil ( Ocimum basilicum L.), oregano ( Origanum vulgare L. subsp. hirticum ), rosemary ( Rosmarinus officinalis L.), clary sage ( Salvia sclarea L.), and thyme ( Thymus vulgaris L.) were tested against bacterial and fungal pathogens previously isolated from dogs and cats with otitis externa. In particular, the analyses were carried out against Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus pseudointermedius , Aspergillus niger, Aspergillus fumigatus, Aspergillus terreus, Candida albicans, Candida tropicalis, Trichosporon sp., and Rhodotorula sp. Results: O. vulgare and S. sclarea showed superior antibacterial activity, even if not against all the strains. Trichosporon sp., C. albicans , and A. terreus were insensitive to most Eos, while other yeasts and molds showed different degrees of sensitivity. In particular, most fungi were inhibited by O. vulgare and R. officinalis . Conclusions: The obtained results suggest that some EOs could be included in treatment as an alternative therapeutic option in bacterial otitis complicated by fungi, in association with conventional drugs.

Superficial mycotic infections of the foot in a native pediatric population: a pathogenic role for Trichosporon cutaneum?

PubMed

Archer-Dubon, Carla; Orozco-Topete, Rocío; Leyva-Santiago, Jaime; Arenas, Roberto; Carbajosa, Josefina; Ysunza, Alberto

2003-01-01

Superficial mycotic infections of the feet are usually caused by Tricophyton rubrum, predominantly affecting adults and resulting from the use of occlusive footwear. We carried out a mycologic study of superficial foot infections in a rural school in Mexico where most people wear a leather, nonocclusive sandal. Forty students had clinical signs of 50 fungal infections of the foot: 39 athlete's foot and 11 onychomycosis. Thirty-one boys and 9 girls were studied. Hyphae were seen in 11 cases of athlete's foot and 5 of onychomycosis. Twenty-one cultures were positive (42%). The most frequently isolated fungi were the opportunistic Trichosporon cutaneum in 42.8%, Candida sp. (23.8%), Trichophyton mentagrophytes (23.8%), and Candida glabrata (9.5%). Superficial mycotic infections of the feet and nails were most frequent in children and adolescents who usually wear nonocclusive shoes. The most frequent pathogens were Candida sp. and T. mentagrophytes. It is interesting to note the prevalence of T. cutaneum that has recently been implicated in mycoses of the feet and nails. We did not isolate T. rubrum in any patient.

Dill (Anethum graveolens L.) seed essential oil induces Candida albicans apoptosis in a metacaspase-dependent manner.

PubMed

Chen, Yuxin; Zeng, Hong; Tian, Jun; Ban, Xiaoquan; Ma, Bingxin; Wang, Youwei

2014-04-01

Dill (Anethum graveolens L.) has been used in traditional Uighur medicine for its various pharmacological activities. Previous studies have suggested that dill seed essential oil (DSEO) has anti-Candida potential and the mechanism of its action also has been studied. Our study examined whether DSEO induces apoptosis in the human pathogen Candida albicans ATCC 64550. Our results indicate that C. albicans ATCC 64550 cells treated with DSEO show some typical apoptosis characters, such as decrease in adenosine triphosphatase (ATPase) activity, chromatin condensation, nuclear fragmentation, and phosphatidylserine (PS) exposure. The DSEO promoted cytochrome c (cyt c) release and metacaspase activation, which resulted in C. albicans ATCC 64550 apoptosis. L-cysteine prevented the DSEO-induced nuclear fragmentation, PS externalization, and metacaspase activation, thus indicating that the reactive oxygen species (ROS) is an important mediator of DSEO-induced apoptosis. To our knowledge, this study is the first to report the induction of apoptosis of this pathogen with concomitant metacaspase activation by DSEO. Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Immunological relatedness among Candida albicans and other pathogenic Candida species.

PubMed Central

Hector, R F; Lyon, F L; Domer, J E

1981-01-01

Membrane-mitochondrial (butanol-hot phosphate-buffered saline) and cytosol (soluble cytoplasmic substances) extracts from seven pathogenic species of Candida were used in in vivo and in vitro immunological assays to study antigenic similarities among the strains with respect to C. albicans. Mice were sensitized with C. albicans serotype A for footpad testing or to provide cells for lymphocyte stimulation assays, and guinea pigs were immunized with whole cells or butanol-hot phosphate-buffered saline extracts of C. albicans to obtain antisera for immunodiffusion assays. When extracts from each of the seven species were used in the assays, they consistently segregated, as determined by statistical or subjective analyses, into three groups. Extracts of C. albicans serotype A or B and C. stellatoidea were the most immunologically reactive in all assays, indicating close similarities between those two species, whereas extracts of C. tropicalis and C. parapsilosis elicited only moderate responses. Extracts from C. krusei, C. guilliermondii, and C. pseudotropicalis were hypo- or nonreactive in the assays, indicating a low level of antigenic relatedness to C. albicans. Images PMID:7037643

IL-17-mediated immunity to the opportunistic fungal pathogen Candida albicans

PubMed Central

Conti, Heather R.; Gaffen, Sarah L.

2015-01-01

IL-17 (IL-17A) has emerged as a key mediator of protection against extracellular microbes, but this cytokine also drives pathology in various autoimmune diseases. Overwhelming data in both humans and mice reveal a clear and surprisingly specific role for IL-17 in protection against the fungus Candida albicans, a commensal of the human oral cavity, gastrointestinal tract and reproductive mucosa. The IL-17 pathway regulates antifungal immunity through upregulation of pro-inflammatory cytokines including IL-6, neutrophil-recruiting chemokines such as CXCL1 and CXCL5 and antimicrobial peptides such as the defensins, which act in concert to limit fungal overgrowth. This review will focus on diseases caused by C. albicans, the role of IL-17-mediated immunity in candidiasis, and the implications for clinical therapies for both autoimmune conditions and fungal infections. PMID:26188072

Candida albicans Chitin Increases Arginase-1 Activity in Human Macrophages, with an Impact on Macrophage Antimicrobial Functions.

PubMed

Wagener, Jeanette; MacCallum, Donna M; Brown, Gordon D; Gow, Neil A R

2017-01-24

The opportunistic human fungal pathogen Candida albicans can cause a variety of diseases, ranging from superficial mucosal infections to life-threatening systemic infections. Phagocytic cells of the innate immune response, such as neutrophils and macrophages, are important first-line responders to an infection and generate reactive oxygen and nitrogen species as part of their protective antimicrobial response. During an infection, host cells generate nitric oxide through the enzyme inducible nitric oxide synthase (iNOS) to kill the invading pathogen. Inside the phagocyte, iNOS competes with the enzyme arginase-1 for a common substrate, the amino acid l-arginine. Several pathogenic species, including bacteria and parasitic protozoans, actively modulate the production of nitric oxide by inducing their own arginases or the host's arginase activity to prevent the conversion of l-arginine to nitric oxide. We report here that C. albicans blocks nitric oxide production in human-monocyte-derived macrophages by induction of host arginase activity. We further determined that purified chitin (a fungal cell wall polysaccharide) and increased chitin exposure at the fungal cell wall surface induces this host arginase activity. Blocking the C. albicans-induced arginase activity with the arginase-specific substrate inhibitor Nω-hydroxy-nor-arginine (nor-NOHA) or the chitinase inhibitor bisdionin F restored nitric oxide production and increased the efficiency of fungal killing. Moreover, we determined that C. albicans influences macrophage polarization from a classically activated phenotype toward an alternatively activated phenotype, thereby reducing antimicrobial functions and mediating fungal survival. Therefore, C. albicans modulates l-arginine metabolism in macrophages during an infection, potentiating its own survival. The availability and metabolism of amino acids are increasingly recognized as crucial regulators of immune functions. In acute infections, the conversion of the "conditionally essential" amino acid l-arginine by the inducible nitric oxide synthase to nitric oxide is a resistance factor that is produced by the host to fight pathogens. Manipulation of these host defense mechanisms by the pathogen can be key to successful host invasion. We show here that the human opportunistic fungal pathogen Candida albicans influences l-arginine availability for nitric oxide production by induction of the substrate-competing host enzyme arginase-1. This led to a reduced production of nitric oxide and, moreover, reduced eradication of the fungus by human macrophages. We demonstrate that blocking of host arginase-1 activity restored nitric oxide production and increased the killing potential of macrophages. These results highlight the therapeutic potential of l-arginine metabolism in fungal diseases. Copyright © 2017 Wagener et al.

Epidemiology, Antifungal Susceptibility, and Pathogenicity of Candida africana Isolates from the United Kingdom

PubMed Central

Szekely, Adrien; Linton, Chistopher J.; Palmer, Michael D.; Brown, Phillipa; Johnson, Elizabeth M.

2013-01-01

Candida africana was previously proposed as a new species within the Candida albicans species complex, together with C. albicans and C. dubliniensis, although further phylogenetic analyses better support its status as an unusual variant within C. albicans. Here we show that C. africana can be distinguished from C. albicans and C. dubliniensis by pyrosequencing of a short region of ITS2, and we have evaluated its occurrence in clinical samples by pyrosequencing all presumptive isolates of C. albicans submitted to the Mycology Reference Laboratory over a 9-month period. The C. albicans complex constituted 826/1,839 (44.9%) of yeast isolates received over the study period and included 783 isolates of C. albicans, 28 isolates of C. dubliniensis, and 15 isolates of C. africana. In agreement with previous reports, C. africana was isolated exclusively from genital specimens, in women in the 18-to-35-year age group. Indeed, C. africana constituted 15/251 (6%) of “C. albicans” isolates from female genital specimens during the study period. C. africana isolates were germ tube positive, grew significantly more slowly than C. albicans and C. dubliniensis on conventional mycological media, could be distinguished from the other members of the C. albicans complex by appearance on chromogenic agar, and were incapable of forming chlamydospores. Here we present the detailed evaluation of epidemiological, phenotypic, and clinical features and antifungal susceptibility profiles of United Kingdom isolates of C. africana. Furthermore, we demonstrate that C. africana is significantly less pathogenic than C. albicans and C. dubliniensis in the Galleria mellonella insect systemic infection model. PMID:23303503

Group X hybrid histidine kinase Chk1 is dispensable for stress adaptation, host-pathogen interactions and virulence in the opportunistic yeast Candida guilliermondii.

PubMed

Navarro-Arias, María J; Dementhon, Karine; Defosse, Tatiana A; Foureau, Emilien; Courdavault, Vincent; Clastre, Marc; Le Gal, Solène; Nevez, Gilles; Le Govic, Yohann; Bouchara, Jean-Philippe; Giglioli-Guivarc'h, Nathalie; Noël, Thierry; Mora-Montes, Hector M; Papon, Nicolas

2017-09-01

Hybrid histidine kinases (HHKs) progressively emerge as prominent sensing proteins in the fungal kingdom and as ideal targets for future therapeutics. The group X HHK is of major interest, since it was demonstrated to play an important role in stress adaptation, host-pathogen interactions and virulence in some yeast and mold models, and particularly Chk1, that corresponds to the sole group X HHK in Candida albicans. In the present work, we investigated the role of Chk1 in the low-virulence species Candida guilliermondii, in order to gain insight into putative conservation of the role of group X HHK in opportunistic yeasts. We demonstrated that disruption of the corresponding gene CHK1 does not influence growth, stress tolerance, drug susceptibility, protein glycosylation or cell wall composition in C. guilliermondii. In addition, we showed that loss of CHK1 does not affect C. guilliermondii ability to interact with macrophages and to stimulate cytokine production by human peripheral blood mononuclear cells. Finally, the C. guilliermondii chk1 null mutant was found to be as virulent as the wild-type strain in the experimental model Galleria mellonella. Taken together, our results demonstrate that group X HHK function is not conserved in Candida species. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Inhibitory effect of chromogenic culture media on the growth of Rhodotorula: relevance to the diagnosis of Rhodotorula spp. infections.

PubMed

Bellanger, Anne-Pauline; Grenouillet, Frédéric; François, Nadine; Skana, Florence; Millon, Laurence

2013-11-01

With the increasing incidence and diverse etiologies of fungal infections, chromogenic yeast culture media are increasingly used for routine diagnosis. Rhodotorula species, which are characterized by the production of carotenoid pigments, are considered as emerging opportunistic pathogens. We recently diagnosed two fungemia due to Rhodotorula spp. and noticed that in both cases, the yeast failed to grow in subculture on the chromogenic yeast culture medium. This study was thus undertaken to investigate more thoroughly the ability (or inability) of Rhodotorula species to grow on different commercially available chromogenic media for yeast. Eighteen Rhodotorula spp. were checked for their ability to grow on four chromogenic yeast culture media: CHROMagar Candida (BD), Candi 4 Select (Biorad), Brilliance Candida (Oxoid), and Candida ID 2 (BioMerieux). All the Rhodotorula spp. strains grew on Brilliance and Candida ID 2, while only six isolates grew on Candi 4, and seven on CHROMagar. Two chromogenic yeast culture media showed a significant inhibitory effect on the growth of Rhodotorula species. As all Rhodotorula species are resistant to echinocandins and fluconazole, it is essential to isolate and identify these yeast quickly to initiate appropriate amphotericin B antifungal treatment as early as possible. The choice of media for routine use should take into account the ability of different media to allow all emerging fungal pathogens to grow. © 2013 APMIS. Published by John Wiley & Sons Ltd.

Synergistic combinations of antifungals and anti-virulence agents to fight against Candida albicans.

PubMed

Cui, Jinhui; Ren, Biao; Tong, Yaojun; Dai, Huanqin; Zhang, Lixin

2015-01-01

Candida albicans, one of the pathogenic Candida species, causes high mortality rate in immunocompromised and high-risk surgical patients. In the last decade, only one new class of antifungal drug echinocandin was applied. The increased therapy failures, such as the one caused by multi-drug resistance, demand innovative strategies for new effective antifungal drugs. Synergistic combinations of antifungals and anti-virulence agents highlight the pragmatic strategy to reduce the development of drug resistant and potentially repurpose known antifungals, which bypass the costly and time-consuming pipeline of new drug development. Anti-virulence and synergistic combination provide new options for antifungal drug discovery by counteracting the difficulty or failure of traditional therapy for fungal infections.

Seasonal variation of the upper digestive tract yeast flora of feral pigeons

USGS Publications Warehouse

Kocan, R.M.; Hasenclever, H.F.

1974-01-01

Feral pigeons were sampled over a 16-month period to determine whether their normal yeast flora varied according to season. Candida albicans and Saccharomyces telluris occurred during the entire sampling period, with C. albicans reaching its highest levels between August and January and S. telluris peaking from March through May. Candida krusei was present for 10 months but exhibited no predictable variation in density. Candida tropicalis, C. guilliermondii and Geotrichum were isolated on several occasions while C. lusitaniae, C. pseudotropicalis and Torulopsis glabrata were each isolated once. The high levels of infection and frequency of occurrence of some yeast species make the feral pigeon highly suspect as a carrier and disseminator of potentially pathogenic yeast.

Fungal model systems and the elucidation of pathogenicity determinants

PubMed Central

Perez-Nadales, Elena; Almeida Nogueira, Maria Filomena; Baldin, Clara; Castanheira, Sónia; El Ghalid, Mennat; Grund, Elisabeth; Lengeler, Klaus; Marchegiani, Elisabetta; Mehrotra, Pankaj Vinod; Moretti, Marino; Naik, Vikram; Oses-Ruiz, Miriam; Oskarsson, Therese; Schäfer, Katja; Wasserstrom, Lisa; Brakhage, Axel A.; Gow, Neil A.R.; Kahmann, Regine; Lebrun, Marc-Henri; Perez-Martin, José; Di Pietro, Antonio; Talbot, Nicholas J.; Toquin, Valerie; Walther, Andrea; Wendland, Jürgen

2014-01-01

Fungi have the capacity to cause devastating diseases of both plants and animals, causing significant harvest losses that threaten food security and human mycoses with high mortality rates. As a consequence, there is a critical need to promote development of new antifungal drugs, which requires a comprehensive molecular knowledge of fungal pathogenesis. In this review, we critically evaluate current knowledge of seven fungal organisms used as major research models for fungal pathogenesis. These include pathogens of both animals and plants; Ashbya gossypii, Aspergillus fumigatus, Candida albicans, Fusarium oxysporum, Magnaporthe oryzae, Ustilago maydis and Zymoseptoria tritici. We present key insights into the virulence mechanisms deployed by each species and a comparative overview of key insights obtained from genomic analysis. We then consider current trends and future challenges associated with the study of fungal pathogenicity. PMID:25011008

Miltefosine inhibits Candida albicans and non-albicans Candida spp. biofilms and impairs the dispersion of infectious cells.

PubMed

Vila, Taissa; Ishida, Kelly; Seabra, Sergio Henrique; Rozental, Sonia

2016-11-01

Candida spp. can adhere to and form biofilms over different surfaces, becoming less susceptible to antifungal treatment. Resistance of biofilms to antifungal agents is multifactorial and the extracellular matrix (ECM) appears to play an important role. Among the few available antifungals for treatment of candidaemia, only the lipid formulations of amphotericin B (AmB) and the echinocandins are effective against biofilms. Our group has previously demonstrated that miltefosine has an important effect against Candida albicans biofilms. Thus, the aim of this work was to expand the analyses of the in vitro antibiofilm activity of miltefosine to non-albicans Candida spp. Miltefosine had significant antifungal activity against planktonic cells and the development of biofilms of C. albicans, Candida parapsilosis, Candida tropicalis and Candida glabrata. The activity profile in biofilms was superior to fluconazole and was similar to that of AmB and caspofungin. Biofilm-derived cells with their ECM extracted became as susceptible to miltefosine as planktonic cells, confirming the importance of the ECM in the biofilm resistant behaviour. Miltefosine also inhibited biofilm dispersion of cells at the same concentration needed to inhibit planktonic cell growth. The data obtained in this work reinforce the potent inhibitory activity of miltefosine on biofilms of the four most pathogenic Candida spp. and encourage further studies for the utilisation of this drug and/or structural analogues on biofilm-related infections. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Distribution and Drug Susceptibility of Candida spp. Associated With Female Genital Tract Infection, Chongqing, China

PubMed Central

Luo, Xiaodong; Dong, Xiaojing; Pen, Zhi

2015-01-01

Background Vulvovaginal candidiasis is defined as vulvovaginitis associated with vaginal carriage of Candida spp. and is a common problem with a high rate of morbidity. Objectives To investigate the distribution of Candida spp. and evaluate the corresponding antifungal susceptibility in women with genital tract infection in Chongqing, southwestern China. Patients and Methods Samples (n = 2.129) were obtained from female patients with symptoms of genital tract infection. Candida spp. were isolated from the specimens and were identified using a coloration medium and the VITEK 2 Compact automatic microbial identification system. Antifungal susceptibility testing was performed using the ATB FUNGUS drug susceptibility testing system. Results From 2,129 samples, 478 (22.45%) isolates of Candida were isolated, of which 395 (82.64%) were Candida albicans, 39 (8.16%) were C. glabrata, 21 (4.39%) were C. tropicalis, 9 (1.88%) were C. parapsilosis, and 14 (2.93%) were other Candida spp. The resistance of C. albicans, C. glabrata, and C. tropicalis to 5 antifungal drugs (amphotericin B, voriconazole, fluconazole, 5-fluorocytosine, and itraconazole) ranged from 0.5% to 6.4%, 0% to 7.7%, and 0% to 9.6%, respectively. Conclusions Candida albicans was the major pathogen associated with candidiasis of the female genital tract in patients in Chongqing. The results of the antifungal sensitivity of the isolates suggest that it is important for clinicians to administer appropriate antifungals for the treatment of Candida spp. infections. PMID:28138369

Clinical and tree hollow populations of human pathogenic yeast in Hamilton, Ontario, Canada are different.

PubMed

Carvalho, Chris; Yang, Jiaqi; Vogan, Aaron; Maganti, Harinad; Yamamura, Deborah; Xu, Jianping

2014-05-01

Yeast are among the most frequent pathogens in humans. The dominant yeast causing human infections belong to the genus Candida and Candida albicans is the most frequently isolated species. However, several non-C. albicans species are becoming increasingly common in patients worldwide. The relationships between yeast in humans and the natural environments remain poorly understood. Furthermore, it is often difficult to identify or exclude the origins of disease-causing yeast from specific environmental reservoirs. In this study, we compared the yeast isolates from tree hollows and from clinics in Hamilton, Ontario, Canada. Our surveys and analyses showed significant differences in yeast species composition, in their temporal dynamics, and in yeast genotypes between isolates from tree hollows and hospitals. Our results are inconsistent with the hypothesis that yeast from trees constitute a significant source of pathogenic yeast in humans in this region. Similarly, the yeast in humans and clinics do not appear to contribute to yeast in tree hollows. © 2013 Blackwell Verlag GmbH.

Soybean toxin (SBTX), a protein from soybeans that inhibits the life cycle of plant and human pathogenic fungi.

PubMed

Morais, Janne Keila S; Gomes, Valdirene M; Oliveira, José Tadeu A; Santos, Izabela S; Da Cunha, Maura; Oliveira, Hermogenes D; Oliveira, Henrique P; Sousa, Daniele O B; Vasconcelos, Ilka M

2010-10-13

Soybean toxin (SBTX) is a 44 kDa glycoprotein that is lethal to mice (LD(50) = 5.6 mg/kg). This study reports the toxicity of SBTX on pathogenic fungi and yeasts and the mechanism of its action. SBTX inhibited spore germination of Aspergillus niger and Penicillium herguei and was toxic to Candida albicans, Candida parapsilosis, Kluyveromyces marxiannus , Pichia membranifaciens, and Saccharomyces cerevisiae. In addition, SBTX hampered the growth of C. albicans and K. marxiannus and inhibited the glucose-stimulated acidification of the incubation medium by S. cerevisiae, suggesting that SBTX interferes with intracellular proton transport to the external medium. Moreover, SBTX caused cell-wall disruption, condensation/shrinkage of cytosol, pseudohyphae formation, and P. membranifaciens and C. parapsilosis cell death. SBTX is toxic to fungi at concentrations far below the dose lethal to mice and has potential in the design of new antifungal drugs or in the development of transgenic crops resistant to pathogens.

Characterisation of Candida within the Mycobiome/Microbiome of the Lower Respiratory Tract of ICU Patients

PubMed Central

Krause, Robert; Halwachs, Bettina; Thallinger, Gerhard G.; Klymiuk, Ingeborg; Gorkiewicz, Gregor; Hoenigl, Martin; Prattes, Jürgen; Valentin, Thomas; Heidrich, Katharina; Buzina, Walter; Salzer, Helmut J. F.; Rabensteiner, Jasmin; Prüller, Florian; Raggam, Reinhard B.; Meinitzer, Andreas; Moissl-Eichinger, Christine; Högenauer, Christoph; Quehenberger, Franz; Kashofer, Karl; Zollner-Schwetz, Ines

2016-01-01

Whether the presence of Candida spp. in lower respiratory tract (LRT) secretions is a marker of underlying disease, intensive care unit (ICU) treatment and antibiotic therapy or contributes to poor clinical outcome is unclear. We investigated healthy controls, patients with proposed risk factors for Candida growth in LRT (antibiotic therapy, ICU treatment with and without antibiotic therapy), ICU patients with pneumonia and antibiotic therapy and candidemic patients (for comparison of truly invasive and colonizing Candida spp.). Fungal patterns were determined by conventional culture based microbiology combined with molecular approaches (next generation sequencing, multilocus sequence typing) for description of fungal and concommitant bacterial microbiota in LRT, and host and fungal biomarkes were investigated. Admission to and treatment on ICUs shifted LRT fungal microbiota to Candida spp. dominated fungal profiles but antibiotic therapy did not. Compared to controls, Candida was part of fungal microbiota in LRT of ICU patients without pneumonia with and without antibiotic therapy (63% and 50% of total fungal genera) and of ICU patients with pneumonia with antibiotic therapy (73%) (p<0.05). No case of invasive candidiasis originating from Candida in the LRT was detected. There was no common bacterial microbiota profile associated or dissociated with Candida spp. in LRT. Colonizing and invasive Candida strains (from candidemic patients) did not match to certain clades withdrawing the presence of a particular pathogenic and invasive clade. The presence of Candida spp. in the LRT rather reflected rapidly occurring LRT dysbiosis driven by ICU related factors than was associated with invasive candidiasis. PMID:27206014

Candida albicans orf19.3727 encodes phytase activity and is essential for human tissue damage

PubMed Central

Fong, Wing-Ping; Samaranayake, Lakshman Perera

2017-01-01

Candida albicans is a clinically important human fungal pathogen. We previously identified the presence of cell-associated phytase activity in C. albicans. Here, we reveal for the first time, that orf19.3727 contributes to phytase activity in C. albicans and ultimately to its virulence potency. Compared with its wild type counterpart, disruption of C. albicans orf19.3727 led to decreased phytase activity, reduced ability to form hyphae, attenuated in vitro adhesion, and reduced ability to penetrate human epithelium, which are the major virulence attributes of this yeast. Thus, orf19.3727 of C. albicans plays a key role in fungal pathogenesis. Further, our data uncover a putative novel strategy for anti-Candidal drug design through inhibition of phytase activity of this common pathogen. PMID:29216308

Identification of the antigenic determinants of factors 8, 9, and 34 of genus Candida.

PubMed

Kobayashi, H; Oyamada, H; Suzuki, A; Shibata, N; Suzuki, S; Okawa, Y

1996-10-21

We investigated the antigenic determinants of factors 8, 9, and 34 of the genus Candida among pathogenic yeasts by enzyme-linked immunosorbent assay (ELISA) using mannans of Saccharomyces cerevisiae wild type and mutant types, mnn 1-mnn 4 and mnn 2. Results of ELISA including antisera against the antigenic factors of genus Candida (Candida Check, latron; FAbs) indicated that these three types of mannan distinctly react with FAbs 34, 8 and 9, respectively. To identify the recognition sites of these FAbs, we compared the ability of various oligosaccharides to inhibit the binding of the mannans to FAbs. The results indicated that FAb 34 preferentially recognizes linear side chains containing a non-reducing terminal alpha-1,3-linked mannose residue, Man(alpha)1 --> 3Man(alpha)1 --> (2Man(alpha)1 --> )n(2Man) (n > or = 0), and that one of the recognition sites of FAb 9 is linear alpha-1,6-linked oligomannosyl series, Man(alpha)1 --> (6Man(alpha)1 --> )n(6Man) (n > or = 2). On the other hand, the recognition site of FAb 8 apparently consisted of two alpha-1,2-linked oligomannosyl side chains and an alpha-1,6-linked mannose residue that originated from the mannan backbone, Man(alpha)1 --> 2Man(alpha)1 --> 2(Man(alpha)1 -->2Man(alpha)1 --> 6)Man.

Genetic susceptibility to Candida infections

PubMed Central

Smeekens, Sanne P; van de Veerdonk, Frank L; Kullberg, Bart Jan; Netea, Mihai G

2013-01-01

Candida spp. are medically important fungi causing severe mucosal and life-threatening invasive infections, especially in immunocompromised hosts. However, not all individuals at risk develop Candida infections, and it is believed that genetic variation plays an important role in host susceptibility. On the one hand, severe fungal infections are associated with monogenic primary immunodeficiencies such as defects in STAT1, STAT3 or CARD9, recently discovered as novel clinical entities. On the other hand, more common polymorphisms in genes of the immune system have also been associated with fungal infections such as recurrent vulvovaginal candidiasis and candidemia. The discovery of the genetic susceptibility to Candida infections can lead to a better understanding of the pathogenesis of the disease, as well as to the design of novel immunotherapeutic strategies. This review is part of the review series on host-pathogen interactions. See more reviews from this series. PMID:23629947

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

Inhibition of Candida albicans biofilm by pure selenium nanoparticles synthesized by pulsed laser ablation in liquids.

PubMed

Guisbiers, Grégory; Lara, Humberto H; Mendoza-Cruz, Ruben; Naranjo, Guillermo; Vincent, Brandy A; Peralta, Xomalin G; Nash, Kelly L

2017-04-01

Selenoproteins play an important role in the human body by accomplishing essential biological functions like oxido-reductions, antioxidant defense, thyroid hormone metabolism and immune response; therefore, the possibility to synthesize selenium nanoparticles free of any contaminants is exciting for future nano-medical applications. This paper reports the first synthesis of selenium nanoparticles by femtosecond pulsed laser ablation in de-ionized water. Those pure nanoparticles have been successfully used to inhibit the formation of Candida albicans biofilms. Advanced electron microscopy images showed that selenium nanoparticles easily adhere on the biofilm, then penetrate into the pathogen, and consequently damage the cell structure by substituting with sulfur. 50% inhibition of Candida albicans biofilm was obtained at only 25 ppm. Finally, the two physical parameters proved to affect strongly the viability of Candida albicans are the crystallinity and particle size. Copyright © 2016 Elsevier Inc. All rights reserved.

Photodynamic therapy with water-soluble phtalocyanines against bacterial biofilms in teeth root canals

NASA Astrophysics Data System (ADS)

Gergova, Raina; Georgieva, Tzvetelina; Angelov, Ivan; Mantareva, Vanya; Valkanov, Serjoga; Mitov, Ivan; Dimitrov, Slavcho

2012-06-01

The study presents the PDT with metal phthalocyanines on biofilms grown in root canals of ten representatives of the Gram-positive and the Gram-negative bacterial species and a fungus Candida albicans which cause aqute teeth infections in root canals.. The extracted human single-root teeth infected for 48 h with microorganisms in conditions to form biofilms of the above pathogens were PDT treated. The stage of biofilm formation and PDT effect of the samples of the teeth were determined by the scaning electron microscopy and with standard microbial tests. The PDT treating procedure included 10 min incubation with the respected phthalocyanine and irradiated with 660 nm Diode laser for 10 min. The most strongly antibacterial activity was achieved with zinc(II) phthalocyanine (ZnPc) against Enterococcus faecalis, Staphylococcus aureus and Moraxella catarrhalis. The other Gram-negative bacteria and Candida albicans were 10-100 times more resistant than the Gram-positive species. The Gram-negative Moraxella catarrhalis and Acinetobacter baumannii were more sensitive than the enterobacteria, but eradication of Pseudomonas aeruginosa in biofilm was insignificant. The influence of the stage of biofilm formation and the initial conditions (bacterial density, photosensitizer concentration and energy fluence of radiation) to the obtained level of inactivation of biofilms was investigated. The PDT with ZnPc photosensitizers show a powerful antimicrobial activity against the most frequent pathogens in endodontic infections and this method for inactivation of pathogens may be used with sucsses for treatment of the bacterial biofilms in the root canals.

Phenotypic characterization of Aspergillus niger and Candida albicans grown under simulated microgravity using a three-dimensional clinostat.

PubMed

Yamazaki, Takashi; Yoshimoto, Maki; Nishiyama, Yayoi; Okubo, Yoichiro; Makimura, Koichi

2012-07-01

The living and working environments of spacecraft become progressively contaminated by a number of microorganisms. A large number of microorganisms, including pathogenic microorganisms, some of which are fungi, have been found in the cabins of space stations. However, it is not known how the characteristics of microorganisms change in the space environment. To predict how a microgravity environment might affect fungi, and thus how their characteristics could change on board spacecraft, strains of the pathogenic fungi Aspergillus niger and Candida albicans were subjected to on-ground tests in a simulated microgravity environment produced by a three-dimensional (3D) clinostat. These fungi were incubated and cultured in a 3D clinostat in a simulated microgravity environment. No positive or negative differences in morphology, asexual reproductive capability, or susceptibility to antifungal agents were observed in cultures grown under simulated microgravity compared to those grown in normal earth gravity (1 G). These results strongly suggest that a microgravity environment, such as that on board spacecraft, allows growth of potentially pathogenic fungi that can contaminate the living environment for astronauts in spacecraft in the same way as they contaminate residential areas on earth. They also suggest that these organisms pose a similar risk of opportunistic infections or allergies in astronauts as they do in people with compromised immunity on the ground and that treatment of fungal infections in space could be the same as on earth. © 2012 The Societies and Blackwell Publishing Asia Pty Ltd.

First report of monomicrobial Candida parapsilosis necrotizing fasciitis.

PubMed

Gassiep, I; Douglas, J; Playford, E G

2016-10-01

Candida parapsilosis is an emerging pathogen worldwide. It commonly causes soft tissue infection; however, to our knowledge there has been no previous report of monomicrobial necrotizing soft tissue infection (NSTI) secondary to C. parapsilosis. We report the first case of NSTI caused by C. parapsilosis in an immunocompromised renal transplant patient, with the diagnosis proven both histologically and microbiologically. Our patient required aggressive surgical intervention and antifungal therapy, with postoperative survival at 90 days. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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.

Antimicrobial activity of yeasts against some pathogenic bacteria

PubMed Central

Younis, Gamal; Awad, Amal; Dawod, Rehab E.; Yousef, Nehal E.

2017-01-01

Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species. Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In addition, all yeast species isolates were subjected to polymerase chain reaction (PCR) for detection of khs (kievitone hydratase) and pelA (pectate degrading enzyme)genes. Results: The recovery rate of yeasts from sausage was 20% (2/10) followed by kareish cheese, processed cheese, and butter 10% (1/10) each as well as raw milk 9% (9/100), and fruit yoghurt 30% (6/20). Different yeast species were recovered, namely, Candida kefyr (5 isolates), Saccharomyces cerevisiae (4 isolates), Candida intermedia (3 isolates), Candida tropicalis (2 isolates), Candida lusitaniae (2 isolates), and Candida krusei (1 isolate). khs gene was detected in all S. cerevisiae isolates, however, pelA gene was not detected in all identified yeast species. Antimicrobial activity of recovered yeasts against the selected bacterial species showed high activity with C. intermedia against S. aureus and E. coli, C. kefyr against E. coli, and C. lusitaniae against S. aureus. Moderate activities were obtained with C. tropicalis, C. lusitaniae, and S. cerevisiae against E. coli; meanwhile, all the tested yeasts revealed a very low antimicrobial activity against P. aeruginosa. Conclusion: The obtained results confirmed that some kinds of yeasts have the ability to produce antimicrobial compounds that could inhibit some pathogenic and spoilage bacteria and these antimicrobial activity of yeasts enables them to be one of the novel agents in controlling spoilage of food. PMID:28919693

ERG2 and ERG24 Are Required for Normal Vacuolar Physiology as Well as Candida albicans Pathogenicity in a Murine Model of Disseminated but Not Vaginal Candidiasis

PubMed Central

Luna-Tapia, Arturo; Peters, Brian M.; Eberle, Karen E.; Kerns, Morgan E.; Foster, Timothy P.; Marrero, Luis; Noverr, Mairi C.; Fidel, Paul L.

2015-01-01

Several important classes of antifungal agents, including the azoles, act by blocking ergosterol biosynthesis. It was recently reported that the azoles cause massive disruption of the fungal vacuole in the prevalent human pathogen Candida albicans. This is significant because normal vacuolar function is required to support C. albicans pathogenicity. This study examined the impact of the morpholine antifungals, which inhibit later steps of ergosterol biosynthesis, on C. albicans vacuolar integrity. It was found that overexpression of either the ERG2 or ERG24 gene, encoding C-8 sterol isomerase or C-14 sterol reductase, respectively, suppressed C. albicans sensitivity to the morpholines. In addition, both erg2Δ/Δ and erg24Δ/Δ mutants were hypersensitive to the morpholines. These data are consistent with the antifungal activity of the morpholines depending upon the simultaneous inhibition of both Erg2p and Erg24p. The vacuoles within both erg2Δ/Δ and erg24Δ/Δ C. albicans strains exhibited an aberrant morphology and accumulated large quantities of the weak base quinacrine, indicating enhanced vacuolar acidification compared with that of control strains. Both erg mutants exhibited significant defects in polarized hyphal growth and were avirulent in a mouse model of disseminated candidiasis. Surprisingly, in a mouse model of vaginal candidiasis, both mutants colonized mice at high levels and induced a pathogenic response similar to that with the controls. Thus, while targeting Erg2p or Erg24p alone could provide a potentially efficacious therapy for disseminated candidiasis, it may not be an effective strategy to treat vaginal infections. The potential value of drugs targeting these enzymes as adjunctive therapies is discussed. PMID:26231054

ERG2 and ERG24 Are Required for Normal Vacuolar Physiology as Well as Candida albicans Pathogenicity in a Murine Model of Disseminated but Not Vaginal Candidiasis.

PubMed

Luna-Tapia, Arturo; Peters, Brian M; Eberle, Karen E; Kerns, Morgan E; Foster, Timothy P; Marrero, Luis; Noverr, Mairi C; Fidel, Paul L; Palmer, Glen E

2015-10-01

Several important classes of antifungal agents, including the azoles, act by blocking ergosterol biosynthesis. It was recently reported that the azoles cause massive disruption of the fungal vacuole in the prevalent human pathogen Candida albicans. This is significant because normal vacuolar function is required to support C. albicans pathogenicity. This study examined the impact of the morpholine antifungals, which inhibit later steps of ergosterol biosynthesis, on C. albicans vacuolar integrity. It was found that overexpression of either the ERG2 or ERG24 gene, encoding C-8 sterol isomerase or C-14 sterol reductase, respectively, suppressed C. albicans sensitivity to the morpholines. In addition, both erg2Δ/Δ and erg24Δ/Δ mutants were hypersensitive to the morpholines. These data are consistent with the antifungal activity of the morpholines depending upon the simultaneous inhibition of both Erg2p and Erg24p. The vacuoles within both erg2Δ/Δ and erg24Δ/Δ C. albicans strains exhibited an aberrant morphology and accumulated large quantities of the weak base quinacrine, indicating enhanced vacuolar acidification compared with that of control strains. Both erg mutants exhibited significant defects in polarized hyphal growth and were avirulent in a mouse model of disseminated candidiasis. Surprisingly, in a mouse model of vaginal candidiasis, both mutants colonized mice at high levels and induced a pathogenic response similar to that with the controls. Thus, while targeting Erg2p or Erg24p alone could provide a potentially efficacious therapy for disseminated candidiasis, it may not be an effective strategy to treat vaginal infections. The potential value of drugs targeting these enzymes as adjunctive therapies is discussed. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Candida krusei isolated from fruit juices ultrafiltration membranes promotes colonization of Escherichia coli O157:H7 and Salmonella enterica on stainless steel surfaces.

PubMed

Tarifa, María Clara; Lozano, Jorge Enrique; Brugnoni, Lorena Inés

2017-02-01

To clarify the interactions between a common food spoilage yeast and two pathogenic bacteria involved in outbreaks associated with fruit juices, the present paper studies the effect of the interplay of Candida krusei, collected from UF membranes, with Escherichia coli O157:H7 and Salmonella enterica in the overall process of adhesion and colonization of abiotic surfaces. Two different cases were tested: a) co-adhesion by pathogenic bacteria and yeasts, and b) incorporation of bacteria to pre-adhered C. krusei cells. Cultures were made on stainless steel at 25°C using apple juice as culture medium. After 24 h of co-adhesion with C. krusei, both E. coli O157:H7 and S. enterica increased their counts 1.05 and 1.11 log CFU cm 2 , respectively. Similar increases were obtained when incorporating bacteria to pre-adhered cells of Candida. Nevertheless C. krusei counts decreased in both experimental conditions, in a) 0.40 log CFU cm 2 and 0.55 log CFU cm 2 when exposed to E. coli O157:H7 and S. enterica and in b) 0.18 and 0.68 log CFU cm 2 , respectively. This suggests that C. krusei, E. coli O157:H7, and S. enterica have a complex relationship involving physical and chemical interactions on food contact surfaces. This study supports the possibility that pathogen interactions with members of spoilage microbiota, such as C. krusei, might play an important role for the survival and dissemination of E. coli O157:H7 and Salmonella enterica in food-processing environments. Based on the data obtained from the present study, much more attention should be given to prevent the contamination of these pathogens in acidic drinks.

An Efficient, Rapid, and Recyclable System for CRISPR-Mediated Genome Editing in Candida albicans.

PubMed

Nguyen, Namkha; Quail, Morgan M F; Hernday, Aaron D

2017-01-01

Candida albicans is the most common fungal pathogen of humans. Historically, molecular genetic analysis of this important pathogen has been hampered by the lack of stable plasmids or meiotic cell division, limited selectable markers, and inefficient methods for generating gene knockouts. The recent development of clustered regularly interspaced short palindromic repeat(s) (CRISPR)-based tools for use with C. albicans has opened the door to more efficient genome editing; however, previously reported systems have specific limitations. We report the development of an optimized CRISPR-based genome editing system for use with C. albicans . Our system is highly efficient, does not require molecular cloning, does not leave permanent markers in the genome, and supports rapid, precise genome editing in C. albicans . We also demonstrate the utility of our system for generating two independent homozygous gene knockouts in a single transformation and present a method for generating homozygous wild-type gene addbacks at the native locus. Furthermore, each step of our protocol is compatible with high-throughput strain engineering approaches, thus opening the door to the generation of a complete C. albicans gene knockout library. IMPORTANCE Candida albicans is the major fungal pathogen of humans and is the subject of intense biomedical and discovery research. Until recently, the pace of research in this field has been hampered by the lack of efficient methods for genome editing. We report the development of a highly efficient and flexible genome editing system for use with C. albicans . This system improves upon previously published C. albicans CRISPR systems and enables rapid, precise genome editing without the use of permanent markers. This new tool kit promises to expedite the pace of research on this important fungal pathogen.

Identification of Candida Species Isolated from Renal Transplant Recipients with Candiduria

PubMed Central

Yazdani, M. R.; Foroughifar, E.; Mohammadi, R.

2016-01-01

Background: Renal transplantation has long been considered the gold standard medical care for patients with end-stage renal disease. Candiduria continue to be a significant complication for renal transplant recipients. The risk of infections depends on the amount of immunosuppression and exposure to the potential pathogens. Objective: Molecular identification of Candida species isolated from renal transplant recipients with candiduria. Methods: Between 2009 and 2014, 62 Candida isolates were collected from 485 renal transplant recipients. All isolates were identified by PCR-RFLP profiles after digestion with the restriction enzyme MspI. Results: C. albicans (44%) and C. parapsilosis complex (5%) had the most and the least prevalence, respectively. Male to female ratio was 26/36, ranging in age from 19 to 62 years. Conclusion: Due to the fact that candiduria is connected with increased mortality in renal transplant recipients, precise identification of Candida species by molecular techniques can lead to an appropriate therapy among high risk patients. C. albicans remains the most prevalent species isolated from renal transplant recipients, Nevertheless, the number of non-C. albicans Candida species looks to be emerging. PMID:28078059

Synergistic combinations of antifungals and anti-virulence agents to fight against Candida albicans

PubMed Central

Cui, Jinhui; Ren, Biao; Tong, Yaojun; Dai, Huanqin; Zhang, Lixin

2015-01-01

Candida albicans, one of the pathogenic Candida species, causes high mortality rate in immunocompromised and high-risk surgical patients. In the last decade, only one new class of antifungal drug echinocandin was applied. The increased therapy failures, such as the one caused by multi-drug resistance, demand innovative strategies for new effective antifungal drugs. Synergistic combinations of antifungals and anti-virulence agents highlight the pragmatic strategy to reduce the development of drug resistant and potentially repurpose known antifungals, which bypass the costly and time-consuming pipeline of new drug development. Anti-virulence and synergistic combination provide new options for antifungal drug discovery by counteracting the difficulty or failure of traditional therapy for fungal infections. PMID:26048362

The epidemiological profile of candidemia at an Indian trauma care center.

PubMed

Tak, Vibhor; Mathur, Purva; Varghese, Prince; Gunjiyal, Jacinta; Xess, Immaculata; Misra, Mahesh C

2014-07-01

Candida spp. is a common cause of bloodstream infections. Candidemia is a potentially fatal infection that needs urgent intervention to salvage the patients. Trauma patients are relatively young individuals with very few comorbidities, and the epidemiology of candidemia is relatively unknown in this vulnerable and growing population. In this study, we report the epidemiology of candidemia in a tertiary care Trauma Center of India. The study was conducted from January 2009 to July 2012. All patients from whose blood samples a Candida spp. was recovered were included in this study. A detailed history and follow up of the patients was done. The isolates of Candida were identified to the species level. The speciation was done by conventional methods, including morphology on Corn Meal Agar, color development on Triphenyl Tetrazolium Chloride Agar and CHROMagar, and germ tube tests. The VITEK 2 YST ID colorometric card, a fully automated identification system was also used. Antifungal susceptibility was performed using the VITEK 2 system. A total of 212 isolates of the Candida species were recovered from blood samples of 157 patients over the study period. Candida tropicalis, 82 (39%), was the most common, followed by C. parapsilosis, 43 (20%), C. albicans, 29 (14%), C. glabrata, 24 (11%), C. rugosa, 20 (9%), C. hemulonii,; 6 (3%), C. guilliermondii, 4 (2%), C. famata, 3 (1.5%), and C. lusitaniae 1 (0.5%). Out of all the candidemia patients, 68 (43%) had a fatal outcome. Fluconazole and Amphotericin B resistance was seen in seven (3.3%) and seven (3.3%) of the isolates, respectively. Candidemia is a significant cause of mortality in trauma patients in our center, with C. tropicalis and C. parapsilosis being the predominant pathogens. Resistance to antifungal drugs is a matter of concern. Better hospital infection control practices and good antibiotic stewardship policies could possibly help in reducing the morbidity and mortality associated with candidemia.

[Study on the relationship between vaginal and intestinal candida in patients with vulvovaginal candidiasis].

PubMed

Lin, Xiao-li; Li, Zhen; Zuo, Xu-lei

2011-07-01

To investigate the relationship between vaginal and intestinal candida in patients with vulvovaginal candidiasis by using microbiological and molecular methods. The samples of vaginal discharge and anal swabs were collected from 148 cases with vulvovaginal candidiasis, followed by fungal culture, identification, purification and genome DNA extraction. The genome sequences from respective locations were aligned and typed according to their homology analyzed by internal transcribed spacer (ITS) PCR and random amplified polymorphic DNA (RAPD) PCR. Patients with vulvovaginal infection or those with infections in intestine and vulvovagina were pooled respectively, while the recurrent incidences after local anti-fungal treatments were analyzed. Candida albicans is the dominant pathogen in 148 cases with vulvovaginal candidiasis (91.9%, 136/148); 33.1% (49/148) of patients with vulvovaginal candidiasis were infected in both intestine and vulvovagina. While 92% (22/24) of patients with intestinal and vaginal candida infection showed high homology. The recurrent rate of patients with vulvovaginal candidiasis complicated with concurrent intestinal candida infection (7/14) was significantly higher than that of solo vaginal infected patients [21% (6/29)] after vaginal treatment (P<0.05). The infection of vulvovaginal candidiasis is highly associated with the concurrent infection of intestinal candida. The recurrent rate is high in patients with vulvovaginal candidiasis with concurrent infection of intestinal candida after vaginal treatment. The general management to those patients infected by both vulvovaginal and intestinal candida is necessary in reducing the recurrence of the disease.

Purification and characterization of antifungal phenazines from a fluorescent Pseudomonas strain FPO4 against medically important fungi.

PubMed

Gorantla, J N; Kumar, S Nishanth; Nisha, G V; Sumandu, A S; Dileep, C; Sudaresan, A; Kumar, M M Sree; Lankalapalli, R S; Kumar, B S Dileep

2014-09-01

The strain FPO4 was isolated from the rhizoplane of rice plant root and identified as a fluorescent Pseudomonas aeruginosa on the basis of 16S rDNA sequences and BLAST analysis. The extracellular metabolites produced by this strain were purified by silica gel column chromatography and isolated four pure compounds. Based on the spectral data the four compounds were identified as phenazin-1-ol, phenazine-1-carboxylic acid (PCA), 2-heptyl-3-hydroxyl-4(1H)-quinolone (PQS), and phenazine-1-carboxamide (PCN), respectively. Phenazin-1-ol and PCA were active against all the eight fungi tested. The highest activity of 4 μg/mL by PCA was recorded against Trichophyton rubrum, a human pathogen responsible for causing athlete's foot, jock itch, ringworm and fingernail fungus infections, followed by Candida albicans and Candida tropicalis. The activity of phenazin-1-ol, PCA against Candida spp. was found to be better than the standard antifungal agent amphotericin B. Furthermore, the present study reports the antimicrobial activity of the purified phenazines on major human pathogen, T. rubrum for the first time. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

The Interface between Fungal Biofilms and Innate Immunity.

PubMed

Kernien, John F; Snarr, Brendan D; Sheppard, Donald C; Nett, Jeniel E

2017-01-01

Fungal biofilms are communities of adherent cells surrounded by an extracellular matrix. These biofilms are commonly found during infection caused by a variety of fungal pathogens. Clinically, biofilm infections can be extremely difficult to eradicate due to their resistance to antifungals and host defenses. Biofilm formation can protect fungal pathogens from many aspects of the innate immune system, including killing by neutrophils and monocytes. Altered immune recognition during this phase of growth is also evident by changes in the cytokine profiles of monocytes and macrophages exposed to biofilm. In this manuscript, we review the host response to fungal biofilms, focusing on how these structures are recognized by the innate immune system. Biofilms formed by Candida, Aspergillus , and Cryptococcus have received the most attention and are highlighted. We describe common themes involved in the resilience of fungal biofilms to host immunity and give examples of biofilm defenses that are pathogen-specific.

Lactobacillus fermentum ATCC 23271 Displays In vitro Inhibitory Activities against Candida spp.

PubMed Central

do Carmo, Monique S.; Noronha, Francisca M. F.; Arruda, Mariana O.; Costa, Ênnio P. da Silva; Bomfim, Maria R. Q.; Monteiro, Andrea S.; Ferro, Thiago A. F.; Fernandes, Elizabeth S.; Girón, Jorge A.; Monteiro-Neto, Valério

2016-01-01

Lactobacilli are involved in the microbial homeostasis in the female genital tract. Due to the high prevalence of many bacterial diseases of the female genital tract and the resistance of microorganisms to various antimicrobial agents, alternative means to control these infections are necessary. Thus, this study aimed to evaluate the probiotic properties of well-characterized Lactobacillus species, including L. acidophilus (ATCC 4356), L. brevis (ATCC 367), L. delbrueckii ssp. delbrueckii (ATCC 9645), L. fermentum (ATCC 23271), L. paracasei (ATCC 335), L. plantarum (ATCC 8014), and L. rhamnosus (ATCC 9595), against Candida albicans (ATCC 18804), Neisseria gonorrhoeae (ATCC 9826), and Streptococcus agalactiae (ATCC 13813). The probiotic potential was investigated by using the following criteria: (i) adhesion to host epithelial cells and mucus, (ii) biofilm formation, (iii) co-aggregation with bacterial pathogens, (iv) inhibition of pathogen adhesion to mucus and HeLa cells, and (v) antimicrobial activity. Tested lactobacilli adhered to mucin, co-aggregated with all genital microorganisms, and displayed antimicrobial activity. With the exception of L. acidophilus and L. paracasei, they adhered to HeLa cells. However, only L. fermentum produced a moderate biofilm and a higher level of co-aggregation and mucin binding. The displacement assay demonstrated that all Lactobacillus strains inhibit C. albicans binding to mucin (p < 0.001), likely due to the production of substances with antimicrobial activity. Clinical isolates belonging to the most common Candida species associated to vaginal candidiasis were inhibited by L. fermentum. Collectively, our data suggest that L. fermentum ATCC 23271 is a potential probiotic candidate, particularly to complement candidiasis treatment, since presented with the best probiotic profile in comparison with the other tested lactobacilli strains. PMID:27833605

The synthesis, regulation, and functions of sterols in Candida albicans: Well-known but still lots to learn.

PubMed

Lv, Quan-Zhen; Yan, Lan; Jiang, Yuan-Ying

2016-08-17

Sterols are the basal components of the membranes of the fungal pathogen Candida albicans, and these membranes determine the susceptibility of C. albicans cells to a variety of stresses, such as ionic, osmotic and oxidative pressures, and treatment with antifungal drugs. The common antifungal azoles in clinical use are targeted to the biosynthesis of ergosterol. In the past years, the synthesis, storage and metabolism of ergosterol in Saccharomyces cerevisiae has been characterized in some detail; however, these processes has not been as well investigated in the human opportunistic pathogen C. albicans. In this review, we summarize the genes involved in ergosterol synthesis and regulation in C. albicans. As well, genes in S. cerevisiae implicated in ergosterol storage and conversions with other lipids are noted, as these provide us clues and directions for the study of the homologous genes in C. albicans. In this report we have particularly focused on the essential roles of ergosterol in the dynamic process of cell biology and its fundamental status in the biological membrane system that includes lipid rafts, lipid droplets, vacuoles and mitochondria. We believe that a thorough understanding of this classic and essential pathway will give us new ideas about drug resistance and morphological switching in C. albicans.

The synthesis, regulation, and functions of sterols in Candida albicans: Well-known but still lots to learn

PubMed Central

Lv, Quan-zhen; Yan, Lan; Jiang, Yuan-ying

2016-01-01

ABSTRACT Sterols are the basal components of the membranes of the fungal pathogen Candida albicans, and these membranes determine the susceptibility of C. albicans cells to a variety of stresses, such as ionic, osmotic and oxidative pressures, and treatment with antifungal drugs. The common antifungal azoles in clinical use are targeted to the biosynthesis of ergosterol. In the past years, the synthesis, storage and metabolism of ergosterol in Saccharomyces cerevisiae has been characterized in some detail; however, these processes has not been as well investigated in the human opportunistic pathogen C. albicans. In this review, we summarize the genes involved in ergosterol synthesis and regulation in C. albicans. As well, genes in S. cerevisiae implicated in ergosterol storage and conversions with other lipids are noted, as these provide us clues and directions for the study of the homologous genes in C. albicans. In this report we have particularly focused on the essential roles of ergosterol in the dynamic process of cell biology and its fundamental status in the biological membrane system that includes lipid rafts, lipid droplets, vacuoles and mitochondria. We believe that a thorough understanding of this classic and essential pathway will give us new ideas about drug resistance and morphological switching in C. albicans. PMID:27221657

Gymnemic Acids Inhibit Hyphal Growth and Virulence in Candida albicans

PubMed Central

Vediyappan, Govindsamy; Dumontet, Vincent; Pelissier, Franck; d’Enfert, Christophe

2013-01-01

Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine. PMID:24040201

Presence and distribution of yeasts in the reproductive tract in healthy female horses.

PubMed

Azarvandi, A; Khosravi, A R; Shokri, H; Talebkhan Garoussi, M; Gharahgouzlou, F; Vahedi, G; Sharifzadeh, A

2017-09-01

Yeasts are commensal organisms found in the reproductive and gastrointestinal tracts, and on the skin and other mucosa in mammals. The purpose of this study was to isolate and identify yeast flora in the caudal reproductive tract in healthy female horses. Longitudinal study. A total of 453 samples were collected using double-guarded swabs from the vestibule, clitoral fossa and vagina in 151 horses. All samples were cultured on Sabouraud 4% dextrose agar and incubated at 35°C for 7-10 days. Isolates were identified according to their morphological characteristics and biochemical profiles. Yeast colonies were isolated from 60 (39.7%) of the 151 horses. The isolated yeasts belonged to nine genera, and included Candida spp. (53.2%), Cryptococcus spp. (12.2%), Saccharomyces spp. (10.5%), Geotrichum spp. (8.0%), Rhodotorula spp. (7.1%), Malassezia spp. (3.7%), Trichosporon spp. (2.6%), Kluyveromyces spp. (2.6%) and Sporothrix spp. (0.2%). Candida krusei (43.1%) was the most frequent Candida species isolated. There was a significant difference in prevalence between C. krusei and other Candida species (P<0.05). The vestibule contained more yeast isolates (48.0%) than the vagina (18.3%). The isolation of yeast colonies from multiparous females (76.8%) was significantly higher than from maiden mares (P<0.05). The study was limited by the difficulty of distinguishing between normal flora and potential pathogens. Candida spp., in particular C. krusei, represent important flora resident in the caudal reproductive tract in healthy female horses. This is particularly important in contexts that require the initiation of empirical treatment prior to the completion of culture results. © 2016 EVJ Ltd.

Challenges and Strategies for Proteome Analysis of the Interaction of Human Pathogenic Fungi with Host Immune Cells.

PubMed

Krüger, Thomas; Luo, Ting; Schmidt, Hella; Shopova, Iordana; Kniemeyer, Olaf

2015-12-14

Opportunistic human pathogenic fungi including the saprotrophic mold Aspergillus fumigatus and the human commensal Candida albicans can cause severe fungal infections in immunocompromised or critically ill patients. The first line of defense against opportunistic fungal pathogens is the innate immune system. Phagocytes such as macrophages, neutrophils and dendritic cells are an important pillar of the innate immune response and have evolved versatile defense strategies against microbial pathogens. On the other hand, human-pathogenic fungi have sophisticated virulence strategies to counteract the innate immune defense. In this context, proteomic approaches can provide deeper insights into the molecular mechanisms of the interaction of host immune cells with fungal pathogens. This is crucial for the identification of both diagnostic biomarkers for fungal infections and therapeutic targets. Studying host-fungal interactions at the protein level is a challenging endeavor, yet there are few studies that have been undertaken. This review draws attention to proteomic techniques and their application to fungal pathogens and to challenges, difficulties, and limitations that may arise in the course of simultaneous dual proteome analysis of host immune cells interacting with diverse morphotypes of fungal pathogens. On this basis, we discuss strategies to overcome these multifaceted experimental and analytical challenges including the viability of immune cells during co-cultivation, the increased and heterogeneous protein complexity of the host proteome dynamically interacting with the fungal proteome, and the demands on normalization strategies in terms of relative quantitative proteome analysis.

Evaluation of CAMP-Like Effect, Biofilm Formation, and Discrimination of Candida africana from Vaginal Candida albicans Species

PubMed Central

Bordbar, Mahboubeh; Nouraei, Hasti; Khodadadi, Hossein

2017-01-01

Candida africana as a species recovered from female genital specimens is highly close to C. albicans. The present study was conducted to discriminate C. africana from presumptive vaginal C. albicans strains by molecular assay and evaluate their hemolysin activity, biofilm formation, and cohemolytic effect (CAMP) with vaginal bacterial flora. A total of 110 stock vaginal C. albicans isolates were examined by HWP1 gene amplification. Hemolysin activity and the ability of biofilm formation were evaluated by blood plate assay and visual detection methods, respectively. Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae were used to evaluate the CAMP-like effects in Sabouraud blood agar media. Based on the size of the amplicons (941 bp), all isolates were identified as C. albicans. All samples were able to produce beta-hemolysin. Moreover, 69 out of 110 of the isolates (62.7%) were biofilm-positive, 54 out of 110 Candida isolates (49%) demonstrated cohemolytic effects with S. agalactiae, and 48 out of 110 showed this effect with S. aureus (43.6%). All isolates were CAMP-negative with S. epidermidis. We detected all isolates as Candida albicans and almost half of the isolates were CAMP-positive with S. aureus and S. agalactiae, suggesting that these bacteria increase the pathogenicity of Candida in vaginal candidiasis. PMID:29318048

[Candida biofilm-related infections].

PubMed

Del Pozo, José Luis; Cantón, Emilia

2016-01-01

The number of biomedical devices (intravascular catheters, heart valves, joint replacements, etc.) that are implanted in our hospitals has increased exponentially in recent years. Candida species are pathogens which are becoming more significant in these kinds of infections. Candida has two forms of development: planktonic and in biofilms. A biofilm is a community of microorganisms which adhere to a surface and are enclosed by an extracellular matrix. This form of development confers a high resistance to the antimicrobial agents. This is the reason why antibiotic treatments usually fail and biomedical devices may have to be removed in most cases. Unspecific adhesion mechanisms, the adhesion-receptor systems, and an intercellular communication system called quorum sensing play an essential role in the development of Candida biofilms. In general, the azoles have poor activity against Candida biofilms, while echinocandins and polyenes show a greater activity. New therapeutic strategies need to be developed due to the high morbidity and mortality and high economic costs associated with these infections. Most studies to date have focused on bacterial biofilms. The knowledge of the formation of Candida biofilms and their composition is essential to develop new preventive and therapeutic strategies. Copyright © 2014 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Culture media profoundly affect Candida albicans and Candida tropicalis growth, adhesion and biofilm development.

PubMed

Weerasekera, Manjula M; Wijesinghe, Gayan K; Jayarathna, Thilini A; Gunasekara, Chinthika P; Fernando, Neluka; Kottegoda, Nilwala; Samaranayake, Lakshman P

2016-11-01

As there are sparse data on the impact of growth media on the phenomenon of biofilm development for Candida we evaluated the efficacy of three culture media on growth, adhesion and biofilm formation of two pathogenic yeasts, Candida albicans and Candida tropicalis. The planktonic phase yeast growth, either as monocultures or mixed cultures, in sabouraud dextrose broth (SDB), yeast nitrogen base (YNB), and RPMI 1640 was compared, and adhesion as well as biofilm formation were monitored using MTT and crystal violet (CV) assays and scanning electron microscopy. Planktonic cells of C. albicans, C. tropicalis and their 1:1 co-culture showed maximal growth in SDB. C. albicans/C. tropicalis adhesion was significantly facilitated in RPMI 1640 although the YNB elicited the maximum growth for C. tropicalis. Similarly, the biofilm growth was uniformly higher for both species in RPMI 1640, and C. tropicalis was the slower biofilm former in all three media. Scanning electron microscopy images tended to confirm the results of MTT and CV assay. Taken together, our data indicate that researchers should pay heed to the choice of laboratory culture media when comparing relative planktonic/biofilm growth of Candida. There is also a need for standardisation of biofilm development media so as to facilitate cross comparisons between laboratories.

Fungi in the cystic fibrosis lung: bystanders or pathogens?

PubMed

Chotirmall, Sanjay H; McElvaney, Noel G

2014-07-01

Improvement to the life expectancy of people with cystic fibrosis (PWCF) brings about novel challenges including the need for evaluation of the role of fungi in the cystic fibrosis (CF) lung. To determine if such organisms represent bystanders or pathogens affecting clinical outcomes we review the existing knowledge from a clinical, biochemical, inflammatory and immunological perspective. The prevalence and importance of fungi in the CF airway has likely been underestimated with the most frequently isolated filamentous fungi being Aspergillus fumigatus and Scedosporium apiospermum and the major yeast Candida albicans. Developing non-culture based microbiological methods for fungal detection has improved both our classification and understanding of their clinical consequences including localized, allergic and systemic infections. Cross-kingdom interaction between bacteria and fungi are discussed as is the role of biofilms further affecting clinical outcome. A combination of host and pathogen-derived factors determines if a particular fungus represents a commensal, colonizer or pathogen in the setting of CF. The underlying immune state, disease severity and treatment burden represent key host variables whilst fungal type, form, chronicity and virulence including the ability to evade immune recognition determines the pathogenic potential of a specific fungus at a particular point in time. Further research in this emerging field is warranted to fully elucidate the spectrum of disease conferred by the presence of fungi in the CF airway and the indications for therapeutic interventions. Copyright © 2014. Published by Elsevier Ltd.

Chlorine-rich plasma polymer coating for the prevention of attachment of pathogenic fungal cells onto materials surfaces

NASA Astrophysics Data System (ADS)

Lamont-Friedrich, Stephanie J.; Michl, Thomas D.; Giles, Carla; Griesser, Hans J.; Coad, Bryan R.

2016-07-01

The attachment of pathogenic fungal cells onto materials surfaces, which is often followed by biofilm formation, causes adverse consequences in a wide range of areas. Here we have investigated the ability of thin film coatings from chlorinated molecules to deter fungal colonization of solid materials by contact killing of fungal cells reaching the surface of the coating. Coatings were deposited onto various substrate materials via plasma polymerization, which is a substrate-independent process widely used for industrial coating applications, using 1,1,2-trichloroethane as the process vapour. XPS surface analysis showed that the coatings were characterized by a highly chlorinated hydrocarbon polymer nature, with only a very small amount of oxygen incorporated. The activity of these coatings against human fungal pathogens was quantified using a recently developed, modified yeast assay and excellent antifungal activity was observed against Candida albicans and Candida glabrata. Plasma polymer surface coatings derived from chlorinated hydrocarbon molecules may therefore offer a promising solution to preventing yeast and mould biofilm formation on materials surfaces, for applications such as air conditioners, biomedical devices, food processing equipment, and others.

Screening of microbial contamination and antimicrobial activity of sea cucumber Holothuria polii.

PubMed

Omran, Nahla E E; Allam, Nanis G

2013-11-01

Microbiological studies were carried out on microbial contamination and antimicrobial activity of sea cucumber Holothuria polii collected from Mediterranean Sea at Abu-kir shore of Alexandria, Egypt. The obtained results revealed the presence of isolates of five human Gram-negative pathogenic bacteria, representing five genera were identified to species level, including, Esherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella sp. and Shigella sp. In addition, an yeast Candida albicans was isolated. The pathogenic bacteria were identified using API 20E strip system (BioMereux). All collected H. polii specimens were healthy with no external signs of infection. Histopathological study of the tegument, intestine and gonads showed no abnormal changes. The antimicrobial activity of two tegumental ethanol extracts (A and B, differ in the method of dehydration) were tested against wide range of pathogenic bacteria and fungi, including intestinal, skin and nosocomial pathogens and one plant fungal pathogen. The results revealed a remarkable antifungal activity of the extract B at 2.5 mg/ml MIC90, especially on Aspergillus niger, Scloretium sp, C. albicans, Aspergillus flavus and Malassezia furfur, and limited antibacterial activity against Gram-negative bacteria (Salmonella choleraesuis ATCC 14028 and Aeromonas hydrophila). The domain of bacterial and limited fungal contamination confirms the results that showed strong antifungal activity of investigated extract.

Genetic and phenotypic intra-species variation in Candida albicans

PubMed Central

Hirakawa, Matthew P.; Martinez, Diego A.; Sakthikumar, Sharadha; Anderson, Matthew Z.; Berlin, Aaron; Gujja, Sharvari; Zeng, Qiandong; Zisson, Ethan; Wang, Joshua M.; Greenberg, Joshua M.; Berman, Judith

2015-01-01

Candida albicans is a commensal fungus of the human gastrointestinal tract and a prevalent opportunistic pathogen. To examine diversity within this species, extensive genomic and phenotypic analyses were performed on 21 clinical C. albicans isolates. Genomic variation was evident in the form of polymorphisms, copy number variations, chromosomal inversions, subtelomeric hypervariation, loss of heterozygosity (LOH), and whole or partial chromosome aneuploidies. All 21 strains were diploid, although karyotypic changes were present in eight of the 21 isolates, with multiple strains being trisomic for Chromosome 4 or Chromosome 7. Aneuploid strains exhibited a general fitness defect relative to euploid strains when grown under replete conditions. All strains were also heterozygous, yet multiple, distinct LOH tracts were present in each isolate. Higher overall levels of genome heterozygosity correlated with faster growth rates, consistent with increased overall fitness. Genes with the highest rates of amino acid substitutions included many cell wall proteins, implicating fast evolving changes in cell adhesion and host interactions. One clinical isolate, P94015, presented several striking properties including a novel cellular phenotype, an inability to filament, drug resistance, and decreased virulence. Several of these properties were shown to be due to a homozygous nonsense mutation in the EFG1 gene. Furthermore, loss of EFG1 function resulted in increased fitness of P94015 in a commensal model of infection. Our analysis therefore reveals intra-species genetic and phenotypic differences in C. albicans and delineates a natural mutation that alters the balance between commensalism and pathogenicity. PMID:25504520

Sensitivity of Candida albicans to essential oils: are they an alternative to antifungal agents?

PubMed

Bona, E; Cantamessa, S; Pavan, M; Novello, G; Massa, N; Rocchetti, A; Berta, G; Gamalero, E

2016-12-01

Candida albicans is an important opportunistic pathogen, responsible for the majority of yeast infections in humans. Essential oils, extracted from aromatic plants, are well-known antimicrobial agents, characterized by a broad spectrum of activities, including antifungal properties. The aim of this work was to assess the sensitivity of 30 different vaginal isolated strains of C. albicans to 12 essential oils, compared to the three main used drugs (clotrimazole, fluconazole and itraconazole). Thirty strains of C. albicans were isolated from vaginal swab on CHROMagar ™ Candida. The agar disc diffusion method was employed to determine the sensitivity to the essential oils. The antifungal activity of the essential oils and antifungal drugs (clotrimazole, itraconazole and fluconazole) were investigated using a microdilution method. Transmission and scanning electron microscopy analyses were performed to get a deep inside on cellular damages. Mint, basil, lavender, tea tree oil, winter savory and oregano essential oils inhibited both the growth and the activity of C. albicans more efficiently than clotrimazole. Damages induced by essential oils at the cellular level were stronger than those caused by clotrimazole. Candida albicans is more sensitive to different essential oils compared to the main used drugs. Moreover, the essential oil affected mainly the cell wall and the membranes of the yeast. The results of this work support the research for new alternatives or complementary therapies against vaginal candidiasis. © 2016 The Society for Applied Microbiology.

PF1163A and B, new antifungal antibiotics produced by Penicillium sp. I. Taxonomy of producing strain, fermentation, isolation and biological activities.

PubMed

Nose, H; Seki, A; Yaguchi, T; Hosoya, A; Sasaki, T; Hoshiko, S; Shomura, T

2000-01-01

Two novel antifungal antibiotics, PF1163A and B, were isolated from the fermentation broth of Penicillium sp. They were purified from the solid cultures of rice media using ethyl acetate extraction, silica gel and Sephadex LH-20 column chromatographies. PF1163A and B showed potent growth inhibitory activity against pathogenic fungal strain Candida albicans but did not show cytotoxic activity against mammalian cells. These compounds inhibited the ergosterol biosynthesis in Candida albicans.

[Infectious risk related to the formation of multi-species biofilms (Candida - bacteria) on peripheral vascular catheters].

PubMed

Seghir, A; Boucherit-Otmani, Z; Sari-Belkharroubi, L; Boucherit, K

2017-03-01

The Candida yeasts are the fourth leading cause of death from systemic infections, the risk may increase when the infection also involves bacteria. Yeasts and bacteria can adhere to medical implants, such as peripheral vascular catheters, and form a multicellular structures called "mixed biofilms" more resistant to antimicrobials agents. However, the formation of mixed biofilms on implants leads to long-term persistent infections because they can act as reservoirs of pathogens that have poorly understood interactions. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Expressed Sequence Tag Analysis of the Human Pathogen Paracoccidioides brasiliensis Yeast Phase: Identification of Putative Homologues of Candida albicans Virulence and Pathogenicity Genes

PubMed Central

Goldman, Gustavo H.; dos Reis Marques, Everaldo; Custódio Duarte Ribeiro, Diógenes; Ângelo de Souza Bernardes, Luciano; Quiapin, Andréa Carla; Vitorelli, Patrícia Marostica; Savoldi, Marcela; Semighini, Camile P.; de Oliveira, Regina C.; Nunes, Luiz R.; Travassos, Luiz R.; Puccia, Rosana; Batista, Wagner L.; Ferreira, Leslie Ecker; Moreira, Júlio C.; Bogossian, Ana Paula; Tekaia, Fredj; Nobrega, Marina Pasetto; Nobrega, Francisco G.; Goldman, Maria Helena S.

2003-01-01

Paracoccidioides brasiliensis, a thermodimorphic fungus, is the causative agent of the prevalent systemic mycosis in Latin America, paracoccidioidomycosis. We present here a survey of expressed genes in the yeast pathogenic phase of P. brasiliensis. We obtained 13,490 expressed sequence tags from both 5′ and 3′ ends. Clustering analysis yielded the partial sequences of 4,692 expressed genes that were functionally classified by similarity to known genes. We have identified several Candida albicans virulence and pathogenicity homologues in P. brasiliensis. Furthermore, we have analyzed the expression of some of these genes during the dimorphic yeast-mycelium-yeast transition by real-time quantitative reverse transcription-PCR. Clustering analysis of the mycelium-yeast transition revealed three groups: (i) RBT, hydrophobin, and isocitrate lyase; (ii) malate dehydrogenase, contigs Pb1067 and Pb1145, GPI, and alternative oxidase; and (iii) ubiquitin, delta-9-desaturase, HSP70, HSP82, and HSP104. The first two groups displayed high mRNA expression in the mycelial phase, whereas the third group showed higher mRNA expression in the yeast phase. Our results suggest the possible conservation of pathogenicity and virulence mechanisms among fungi, expand considerably gene identification in P. brasiliensis, and provide a broader basis for further progress in understanding its biological peculiarities. PMID:12582121

Identification of infection- and defense-related genes via a dynamic host-pathogen interaction network using a Candida albicans-zebrafish infection model.

PubMed

Kuo, Zong-Yu; Chuang, Yung-Jen; Chao, Chun-Cheih; Liu, Fu-Chen; Lan, Chung-Yu; Chen, Bor-Sen

2013-01-01

Candida albicans infections and candidiasis are difficult to treat and create very serious therapeutic challenges. In this study, based on interactive time profile microarray data of C. albicans and zebrafish during infection, the infection-related protein-protein interaction (PPI) networks of the two species and the intercellular PPI network between host and pathogen were simultaneously constructed by a dynamic interaction model, modeled as an integrated network consisting of intercellular invasion and cellular defense processes during infection. The signal transduction pathways in regulating morphogenesis and hyphal growth of C. albicans were further investigated based on significant interactions found in the intercellular PPI network. Two cellular networks were also developed corresponding to the different infection stages (adhesion and invasion), and then compared with each other to identify proteins from which we can gain more insight into the pathogenic role of hyphal development in the C. albicans infection process. Important defense-related proteins in zebrafish were predicted using the same approach. The hyphal growth PPI network, zebrafish PPI network and host-pathogen intercellular PPI network were combined to form an integrated infectious PPI network that helps us understand the systematic mechanisms underlying the pathogenicity of C. albicans and the immune response of the host, and may help improve medical therapies and facilitate the development of new antifungal drugs. Copyright © 2013 S. Karger AG, Basel.

Prevalence of Candida albicans, Candida dubliniensis and Candida africana in pregnant women suffering from vulvovaginal candidiasis in Argentina.

PubMed

Mucci, María Josefina; Cuestas, María Luján; Landanburu, María Fernanda; Mujica, María Teresa

Vulvovaginal candidiasis (VVC) is a vulvovaginitis commonly diagnosed in gynecology care. In recent years, the taxonomy of the most important pathogenic Candida species, such as Candida albicans have undergone significant changes. This study examined the prevalence of C. albicans, Candida africana, and Candida dubliniensis in vaginal specimens from 210 pregnant women suffering from vulvovaginitis or having asymptomatic colonization. Phenotypic and molecular methods were used for the identification of the species. During the studied period, 55 isolates of Candida or other yeasts were obtained from specimens collected from 52 patients suffering from vulvovaginitis (24.8%). C. albicans was the predominant Candida species in 42 isolates (80.7%), either alone or in combination with other species of the genus (5.7%, n=3). Additionally, nine isolates of C. albicans (50%) were obtained from asymptomatic patients (n=18). C. dubliniensis was the causative agent in 2 (3.8%) cases of VVC, and was also isolated in one asymptomatic patient. Molecular assays were carried out using specific PCR to amplify the ACT1-associated intron sequence of C. dubliniensis. The amplification of the HWP1 gene also correctly identified isolates of the species C. albicans and C. dubliniensis. No C. africana was isolated in this work. Some C. albicans isolates were either homozygous or heterozygous at the HWP1 locus. The distribution of heterozygous and homozygous C. albicans isolates at the HWP1 locus was very similar among patients suffering from VVC and asymptomatic patients (p=0.897). The presence of C. albicans and C. dubliniensis, and the absence of C. africana in pregnant is noteworthy. 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.

First report of sporadic cases of Candida auris in Colombia.

PubMed

Parra-Giraldo, Claudia M; Valderrama, Sandra L; Cortes-Fraile, Gloria; Garzón, Javier R; Ariza, Beatriz E; Morio, Florent; Linares-Linares, Melva Y; Ceballos-Garzón, Andrés; de la Hoz, Alejandro; Hernandez, Catalina; Alvarez-Moreno, Carlos; Le Pape, Patrice

2018-04-01

Candida auris is a recently reported Candida species that is phenotypically similar to Candida haemulonii and related to hospital outbreaks. This organism can be misidentified as Candida haemulonii, Candida famata, Candida catenulata, or Rhodotorula glutinis by phenotypic approaches. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and DNA sequence analysis using internal transcribed spacer rDNA bar-coding provide an accurate identification. Three cases of C. auris infection in patients with risk factors for fungal infection (one admitted to the intensive care unit, one with lymphoma, and one with HIV; all three with previous antibiotic use) are reported; these infections were not epidemiologically related. Yeast isolates were recovered from blood, ocular secretion, and bronchoalveolar lavage and were misidentified as C. catenulata and Candida albicans by the phenotypic MicroScan method. The isolates were confirmed to be C. auris by means of MALDI-TOF MS and DNA sequence analysis. Antifungal susceptibility testing was performed on these C. auris isolates, which exhibited high minimum inhibitory concentrations to triazoles and amphotericin B. One patient survived and the other two died. Only one of these deaths was related to fungemia. C. auris is an emerging and opportunistic multidrug-resistant human pathogen. It is necessary to strengthen measures to achieve an accurate and quick identification and also to avoid its dissemination. This will require improvements in health and infection control measures, as well as the promotion of antifungal stewardship in healthcare facilities. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Tissue-Resident Macrophages in Fungal Infections.

PubMed

Xu, Shengjie; Shinohara, Mari L

2017-01-01

Invasive fungal infections result in high morbidity and mortality. Host organs targeted by fungal pathogens vary depending on the route of infection and fungal species encountered. Cryptococcus neoformans infects the respiratory tract and disseminates throughout the central nervous system. Candida albicans infects mucosal tissues and the skin, and systemic Candida infection in rodents has a tropism to the kidney. Aspergillus fumigatus reaches distal areas of the lung once inhaled by the host. Across different tissues in naïve hosts, tissue-resident macrophages (TRMs) are one of the most populous cells of the innate immune system. Although they function to maintain homeostasis in a tissue-specific manner during steady state, TRMs may function as the first line of defense against invading pathogens and may regulate host immune responses. Thus, in any organs, TRMs are uniquely positioned and specifically programmed to function. This article reviews the current understanding of the roles of TRMs during major fungal infections.

Multidrug-Resistant Candida haemulonii and C. auris, Tel Aviv, Israel.

PubMed

Ben-Ami, Ronen; Berman, Judith; Novikov, Ana; Bash, Edna; Shachor-Meyouhas, Yael; Zakin, Shiri; Maor, Yasmin; Tarabia, Jalal; Schechner, Vered; Adler, Amos; Finn, Talya

2017-02-01

Candida auris and C. haemulonii are closely related, multidrug-resistant emerging fungal pathogens that are not readily distinguishable with phenotypic assays. We studied C. auris and C. haemulonii clinical isolates from 2 hospitals in central Israel. C. auris was isolated in 5 patients with nosocomial bloodstream infection, and C. haemulonii was found as a colonizer of leg wounds at a peripheral vascular disease clinic. Liberal use of topical miconazole and close contact among patients were implicated in C. haemulonii transmission. C. auris exhibited higher thermotolerance, virulence in a mouse infection model, and ATP-dependent drug efflux activity than C. haemulonii. Comparison of ribosomal DNA sequences found that C. auris strains from Israel were phylogenetically distinct from isolates from East Asia, South Africa and Kuwait, whereas C. haemulonii strains from different countries were closely interrelated. Our findings highlight the pathogenicity of C. auris and underscore the need to limit its spread.

The combined rapid detection and species-level identification of yeasts in simulated blood culture using a colorimetric sensor array

PubMed Central

Lim, Sung H.; Wilson, Deborah A.; SalasVargas, Ana Victoria; Churi, Yair S.; Rhodes, Paul A.; Mazzone, Peter J.; Procop, Gary W.

2017-01-01

Background A colorimetric sensor array (CSA) has been demonstrated to rapidly detect and identify bacteria growing in blood cultures by obtaining a species-specific “fingerprint” of the volatile organic compounds (VOCs) produced during growth. This capability has been demonstrated in prokaryotes, but has not been reported for eukaryotic cells growing in culture. The purpose of this study was to explore if a disposable CSA could differentially identify 7 species of pathogenic yeasts growing in blood culture. Methods Culture trials of whole blood inoculated with a panel of clinically important pathogenic yeasts at four different microorganism loads were performed. Cultures were done in both standard BacT/Alert and CSA-embedded bottles, after adding 10 mL of spiked blood to each bottle. Color changes in the CSA were captured as images by an optical scanner at defined time intervals. The captured images were analyzed to identify the yeast species. Time to detection by the CSA was compared to that in the BacT/Alert system. Results One hundred sixty-two yeast culture trials were performed, including strains of several species of Candida (Ca. albicans, Ca. glabrata, Ca. parapsilosis, and Ca. tropicalis), Clavispora (synonym Candida) lusitaniae, Pichia kudriavzevii (synonym Candida krusei) and Cryptococcus neoformans, at loads of 8.2 × 105, 8.3 × 103, 8.5 × 101, and 1.7 CFU/mL. In addition, 8 negative trials (no yeast) were conducted. All negative trials were correctly identified as negative, and all positive trials were detected. Colorimetric responses were species-specific and did not vary by inoculum load over the 500000-fold range of loads tested, allowing for accurate species-level identification. The mean sensitivity for species-level identification by CSA was 74% at detection, and increased with time, reaching almost 95% at 4 hours after detection. At an inoculum load of 1.7 CFU/mL, mean time to detection with the CSA was 6.8 hours (17%) less than with the BacT/Alert platform. Conclusion The CSA combined rapid detection of pathogenic yeasts in blood culture with accurate species-level identification. PMID:28296967

The combined rapid detection and species-level identification of yeasts in simulated blood culture using a colorimetric sensor array.

PubMed

Shrestha, Nabin K; Lim, Sung H; Wilson, Deborah A; SalasVargas, Ana Victoria; Churi, Yair S; Rhodes, Paul A; Mazzone, Peter J; Procop, Gary W

2017-01-01

A colorimetric sensor array (CSA) has been demonstrated to rapidly detect and identify bacteria growing in blood cultures by obtaining a species-specific "fingerprint" of the volatile organic compounds (VOCs) produced during growth. This capability has been demonstrated in prokaryotes, but has not been reported for eukaryotic cells growing in culture. The purpose of this study was to explore if a disposable CSA could differentially identify 7 species of pathogenic yeasts growing in blood culture. Culture trials of whole blood inoculated with a panel of clinically important pathogenic yeasts at four different microorganism loads were performed. Cultures were done in both standard BacT/Alert and CSA-embedded bottles, after adding 10 mL of spiked blood to each bottle. Color changes in the CSA were captured as images by an optical scanner at defined time intervals. The captured images were analyzed to identify the yeast species. Time to detection by the CSA was compared to that in the BacT/Alert system. One hundred sixty-two yeast culture trials were performed, including strains of several species of Candida (Ca. albicans, Ca. glabrata, Ca. parapsilosis, and Ca. tropicalis), Clavispora (synonym Candida) lusitaniae, Pichia kudriavzevii (synonym Candida krusei) and Cryptococcus neoformans, at loads of 8.2 × 105, 8.3 × 103, 8.5 × 101, and 1.7 CFU/mL. In addition, 8 negative trials (no yeast) were conducted. All negative trials were correctly identified as negative, and all positive trials were detected. Colorimetric responses were species-specific and did not vary by inoculum load over the 500000-fold range of loads tested, allowing for accurate species-level identification. The mean sensitivity for species-level identification by CSA was 74% at detection, and increased with time, reaching almost 95% at 4 hours after detection. At an inoculum load of 1.7 CFU/mL, mean time to detection with the CSA was 6.8 hours (17%) less than with the BacT/Alert platform. The CSA combined rapid detection of pathogenic yeasts in blood culture with accurate species-level identification.

Pathogenic Gut Flora in Patients With Chronic Heart Failure.

PubMed

Pasini, Evasio; Aquilani, Roberto; Testa, Cristian; Baiardi, Paola; Angioletti, Stefania; Boschi, Federica; Verri, Manuela; Dioguardi, Francesco

2016-03-01

The goal of this study was to measure the presence of pathogenic gut flora and intestinal permeability (IP) and their correlations with disease severity, venous blood congestion, and inflammation in patients with chronic heart failure (CHF). Evidence suggests that translocation of gut flora and/or their toxins from the intestine to the bloodstream is a possible trigger of systemic CHF inflammation. However, the relation between pathogenic gut flora and CHF severity, as well as IP, venous blood congestion as right atrial pressure (RAP), and/or systemic inflammation (C-reactive protein [CRP]), is still unknown. This study analyzed 60 well-nourished patients in stable condition with mild CHF (New York Heart Association [NYHA] functional class I to II; n = 30) and moderate to severe CHF (NYHA functional class III to IV; n = 30) and matched healthy control subjects (n = 20). In all subjects, the presence and development in the feces of bacteria and fungi (Candida species) were measured; IP according to cellobiose sugar test results was documented. The study data were then correlated with RAP (echocardiography) and systemic inflammation. Compared with normal control subjects, the entire CHF population had massive quantities of pathogenic bacteria and Candida such as Campylobacter (85.3 ± 3.7 CFU/ml vs. 1.0 ± 0.3 CFU/ml; p < 0.001), Shigella (38.9 ± 12.3 CFU/ml vs. 1.6 ± 0.2 CFU/ml; p < 0.001), Salmonella (31.3 ± 9.1 CFU/ml vs 0 CFU/ml; p < 0.001), Yersinia enterocolitica (22.9 ± 6.3 CFU/ml vs. 0 CFU/ml; p < 0.0001), and Candida species (21.3 ± 1.6 CFU/ml vs. 0.8 ± 0.4 CFU/ml; p < 0.001); altered IP (10.2 ± 1.2 mg vs. 1.5 ± 0.8 mg; p < 0.001); and increased RAP (12.6 ± 0.6 mm Hg) and inflammation (12.5 ± 0.6 mg/dl). These variables were more pronounced in patients with moderate to severe NYHA functional classes than in patients with the mild NYHA functional class. Notably, IP, RAP, and CRP were mutually interrelated (IP vs. RAP, r = 0.55; p < 0.0001; IP vs. CRP, r = 0.78; p < 0.0001; and RAP vs. CRP, r = 0.78; p < 0.0001). This study showed that patients with CHF may have intestinal overgrowth of pathogenic bacteria and Candida species and increased IP associated with clinical disease severity, venous blood congestion, and inflammation. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Identification of virulence determinants of the human pathogenic fungi Aspergillus fumigatus and Candida albicans by proteomics.

PubMed

Kniemeyer, Olaf; Schmidt, André D; Vödisch, Martin; Wartenberg, Dirk; Brakhage, Axel A

2011-06-01

Both fungi Candida albicans and Aspergillus fumigatus can cause a number of life-threatening systemic infections in humans. The commensal yeast C. albicans is one of the main causes of nosocomial fungal infectious diseases, whereas the filamentous fungus A. fumigatus has become one of the most prevalent airborne fungal pathogens. Early diagnosis of these fungal infections is challenging, only a limited number of antifungals for treatment are available, and the molecular details of pathogenicity are hardly understood. The completion of both the A. fumigatus and C. albicans genome sequence provides the opportunity to improve diagnosis, to define new drug targets, to understand the functions of many uncharacterised proteins, and to study protein regulation on a global scale. With the application of proteomic tools, particularly two-dimensional gel electrophoresis and LC/MS-based methods, a comprehensive overview about the proteins of A. fumigatus and C. albicans present or induced during environmental changes and stress conditions has been obtained in the past 5 years. However, for the discovery of further putative virulence determinants, more sensitive and targeted proteomic methods have to be applied. Here, we review the recent proteome data generated for A. fumigatus and C. albicans that are related to factors required for pathogenicity. Copyright © 2011 Elsevier GmbH. All rights reserved.

Effects of Vernonia cinerea less methanol extract on growth and morphogenesis of Candida albicans.

PubMed

Latha, L Yoga; Darah, I; Jain, K; Sasidharan, S

2011-05-01

Vernonia (V.) cinerea Less (Asteraceae) have many therapeutic uses in the practice of traditional medicine. The methanol extract of V cinerea, was screened for antiyeast activity against pathogenic yeast Candida albicans. The antimicrobial activities were studied by using disc diffusion method and broth dilution method. The effect of the extract on the growth profile of the yeast was also examined via time-kill assay. In addition to the fungicidal effects study, microscopic observations using Scanning (SEM) electron microscopy, Transmission (TEM) electron microscopy and light microscopy (LM) were done to determine the major alterations in the microstructure of Candida (C) albicans. The extract showed a favorable antimicrobial activity against C. albicans with a minimum inhibitory concentration (MIC) value of 1.56 mg/mL. Time-kill assay suggested that Vernonia cinerea extract had completely inhibited Candida albicans growth and also exhibited prolonged antiyeast activity. The main abnormalities notes from these microscopic observations were the alterations in morphology and complete collapse of the yeast cells after 36 h of exposure to the extract. The extract of Vernonia cinerea may be an effective agent to treat the Candida albicans infection.

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.

Fungistatic activity of some perfumes against otomycotic pathogens.

PubMed

Jain, S K; Agrawal, S C

2002-04-01

The sporostatic effect of five otomycotic pathogens, i.e. Aspergillus niger, A. flavus, Absidia corymbifera, Penicillium nigricans and Candida albicans to nine different perfumes was determined on the basis of their spore germination. These organisms were isolated from patients suffering from fungal infection of the external auditory canal. Volatile vapours emanating from musk, phulwari, jasmine, nagchampa and bela caused approximately 100% inhibition in spore germination of all the test fungi. Volatiles emanating from chandan, khas and hina showed no inhibition for the test pathogens, displaying their resistant character to these perfumes.

[Aorto-bifermoral grafs infection due to Candida parapsilosis. An unusual pathogen].

PubMed

Guevara-Noriega, Kerbi Alejandro; Velescu, Alina; Zaffalon-Espinal, Diana Teresa; Mateos-Torres, Eduardo; Roig-Santamaría, Luis; Clará-Velasco, Albert

Aorto-enteric fistula is a rare and potentially lethal entity. Its presentation may be as an enteric-paraprosthetic fistula, due to injury in the gut caused by direct contact with the vascular prosthesis. We report a case of enteric-paraprosthetic fistulae with the unusual finding of Candida parapsilosis as the only isolated pathogen. A 65-year-old male, smoker, with aortobifemoral revascularisation with dacron due to aortoiliac occlusive disease, and re-intervention for thrombosis of left arm at 6 months. Hospitalisation at 22 months was required due to a toxic syndrome, which was diagnosed as enteric-paraprosthetic fistulae after complementary studies. The graft was removed and an extra-anatomic revascularisation was performed. Microbiology specimens taken from the duodenal segment in contact with the prosthesis showed the prosthetic segment and peri-prosthetic fluid were positive to C. parapsilosis. The finding of C. parapsilosis in all cultures taken during surgery, along with negative blood cultures and no other known sources of infection, is of interest. It is an unusual pathogen with low virulence and limited as regards other Candida species. Our patient had no clinical data common to cases of infection with C. parapsilosis, and the mechanism of graft infection is unknown. Graft infection by C. parapsilosis may be anecdotal. However, its consequences can also be severe. Microbiological tests can be useful to adjust antimicrobial therapy in the post-operative period, but their usefulness for determining the aetiology is doubtful, as it may be just an incidental finding. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Lower genital tract infections in infertile Nigerian women compared with controls.

PubMed

Okonofua, F E; Ako-Nai, K A; Dighitoghi, M D

1995-06-01

To investigate the possibility that infertile Nigerian women have a higher rate of cervical colonisation with pathogenic and facultative organisms than fertile controls. The prevalence of common microorganisms in the vagina and endocervical canals of infertile women was compared with that of pregnant controls. The Obafemi Awolowo University Hospital Maternity Centre. 92 infertile women were compared with 86 pregnant controls. rates of isolation of Neisseria gonorrhoeae, Candida albicans, Trichomonas vaginalis and other facultative organisms in cases and controls. The rate of isolation of Neisseria gonorrheae was 17.4% among infertile women compared with 10.5% in the group of pregnant women (p > 0.05). There was no significant difference between the groups in the rate of isolation of Candida albicans, Trichomonas vaginalis and other facultative organisms. High rates of isolation of microorganisms were observed in both groups. However, women with secondary infertility had higher rate of carriage of Neisseria gonorrheae, Candida albicans and Staphylococcus aureus as compared with women with primary infertility. Nearly 15% of infertile women had previous episodes of pelvic inflammatory disease and 26% had had induced abortions. A positive history of vaginal discharge was a poor predictor of vagina and endocervical carriage of microorganisms. High rates of pathogenic organisms exist in the lower genital tract of infertile women and controls. Women with secondary infertility are more likely to have pathogenic organisms than women with primary infertility. A policy of routinely screening women for lower genital tract infections should be pursued in this population because of the high rate of infection.

Invasive candidiasis: future directions in non-culture based diagnosis.

PubMed

Posch, Wilfried; Heimdörfer, David; Wilflingseder, Doris; Lass-Flörl, Cornelia

2017-09-01

Delayed initial antifungal therapy is associated with high mortality rates caused by invasive candida infections, since accurate detection of the opportunistic pathogenic yeast and its identification display a diagnostic challenge. diagnosis of candida infections relies on time-consuming methods such as blood cultures, serologic and histopathologic examination. to allow for fast detection and characterization of invasive candidiasis, there is a need to improve diagnostic tools. trends in diagnostics switch to non-culture-based methods, which allow specified diagnosis within significantly shorter periods of time in order to provide early and appropriate antifungal treatment. Areas covered: within this review comprise novel pathogen- and host-related testing methods, e.g. multiplex-PCR analyses, T2 magnetic resonance, fungus-specific DNA microarrays, microRNA characterization or analyses of IL-17 as biomarker for early detection of invasive candidiasis. Expert commentary: Early recognition and diagnosis of fungal infections is a key issue for improved patient management. As shown in this review, a broad range of novel molecular based tests for the detection and identification of Candida species is available. However, several assays are in-house assays and lack standardization, clinical validation as well as data on sensitivity and specificity. This underscores the need for the development of faster and more accurate diagnostic tests.

Microbiological Assessment of Moringa Oleifera Extracts and Its Incorporation in Novel Dental Remedies against Some Oral Pathogens

PubMed Central

Elgamily, Hanaa; Moussa, Amani; Elboraey, Asmaa; EL-Sayed, Hoda; Al-Moghazy, Marwa; Abdalla, Aboelfetoh

2016-01-01

AIM: To assess the antibacterial and antifungal potentials of different parts of Moringa oleifera plant using different extraction methods in attempts to formulate natural dental remedies from this plant. MATERIAL AND METHODS: Three solvents extracts (Ethanol, acetone, and ethyl acetate) of different parts of Egyptian Moringa tree were prepared and tested against oral pathogens: Staphylococcus aureus, Streptococcus mutans, and Candida albicans using disc diffusion method; As well as to incorporate the plant extract to formulate experimental toothpaste and mouthwash. The two dental remedies were assessed against the same microbial strains. Statistical analysis was performed using One-Way ANOVA test to compare the inhibition zone diameter and t-test. RESULTS: Ethanol extracts as well as leaves extracts demonstrated the highest significant mean inhibition zone values (P ≤ 0.05) against Staphylococcus aureus and Streptococcus mutans growth. However, all extracts revealed no inhibition zone against Candida albicans. For dental remedies, experimental toothpaste exhibited higher mean inhibition than the mouthwash against Staphylococcus aureus, Streptococcus mutans and only the toothpaste revealed antifungal effect against Candida albicans. CONCLUSION: The different extracts of different parts of Moringa showed an antibacterial effect against Staphylococcus aureus and Streptococcus mutans growth. The novel toothpaste of ethanolic leaves extract has antimicrobial and antifungal potential effects all selected strains. PMID:28028395

EQUAL Candida Score: An ECMM score derived from current guidelines to measure QUAlity of Clinical Candidaemia Management.

PubMed

Mellinghoff, Sibylle C; Hoenigl, Martin; Koehler, Philipp; Kumar, Anil; Lagrou, Katrien; Lass-Flörl, Cornelia; Meis, Jacques F; Menon, Vidya; Rautemaa-Richardson, Riina; Cornely, Oliver A

2018-05-01

Candida species frequently cause blood stream infections and are reported to be the third to tenth most commonly isolated pathogens. Guidelines and standardised treatment algorithms provided by professional organisations aim to facilitate decision-making regarding diagnosis, management and treatment of candidaemia. In routine clinical practise, however, it may be challenging to comply with these guidelines. The reasons include lack of familiarity or feasibility to adherence, but also their length and complexity. There is no tool to measure guideline adherence currently. To provide such a tool, we reviewed the current guidelines provided by the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and by the Infectious Diseases Society of America (IDSA), and selected the strongest recommendations for management quality as the bases for our scoring tool. Factors incorporated were diagnostic (blood cultures, echocardiography, ophthalmoscopy, species identification) and follow-up procedures (repeat blood cultures until negative result) as well as key treatment parameters (echinocandin treatment, step down to fluconazole depending on susceptibility result, CVC removal). The EQUAL Candida Score weighs and aggregates factors recommended for the ideal management of candidaemia and provides a tool for antifungal stewardship as well as for measuring guideline adherence. © 2018 Blackwell Verlag GmbH.

Efficient click chemistry towards fatty acids containing 1,2,3-triazole: Design and synthesis as potential antifungal drugs for Candida albicans.

PubMed

Fu, Nina; Wang, Suiliang; Zhang, Yuqian; Zhang, Caixia; Yang, Dongliang; Weng, Lixing; Zhao, Baomin; Wang, Lianhui

2017-08-18

Candida is an important opportunistic human fungal pathogen. The cis-2-dodecenoic acid (BDSF) showing in vitro activity of against C. albicans growth, germ-tube germination and biofilm formation has been a potential inhibitor for Candida and other fungi. In this study, facile synthetic strategies toward a novel family of BDSF analogue, 1-alkyl-1H-1,2,3-triazole-4-carboxylic acids (ATCs) was developed. The straightforward synthetic method including converting the commercial available alkyl bromide to alkyl azide, consequently with a typical click chemistry method, copper(II) sulfate and sodium ascorbate as catalyst in water to furnish ATCs with mild to good yields. According to antifungal assay, 1-decyl-4,5-dihydro-1H-1,2,3-triazole-4-carboxylic acid (5d) showed antifungal capability slightly better than BDSF. The 1,2,3-triazole unit played a crucial role for the bioactivity of ATCs was also confirmed when compared with two alkyl-aromatic carboxylic acids. Given its simplicity, high antifungal activity, and wide availability of compounds with halide atoms on the end part of the alkyl chains, the method can be extended to develop more excellent ATC drugs for accomplishing the challenges in future antifungal applications. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Emerging Drugs and Vaccines for Candidemia

PubMed Central

Moriyama, Brad; Gordon, Lori A.; McCarthy, Matthew; Henning, Stacey A.; Walsh, Thomas J.; Penzak, Scott R.

2014-01-01

Summary Candidemia and other forms of invasive candidiasis are important causes of morbidity and mortality. The evolving challenge of antimicrobial resistance among fungal pathogens continues to highlight the need for potent, new antifungal agents. MEDLINE, EMBASE, Scopus, and Web of Science searches (up to January 2014) of the English-language literature were performed with the keywords “Candida” or “Candidemia” or “Candidiasis” and terms describing investigational drugs with activity against Candida spp. Conference abstracts and the bibliographies of pertinent articles were also reviewed for relevant reports. ClinicalTrials.gov was searched for relevant clinical trials. Currently available antifungal agents for the treatment of candidemia are summarized. Investigational antifungal agents with potential activity against Candida bloodstream infections and other forms of invasive candidiasis and vaccines for prevention of Candida infections are also reviewed as are selected antifungal agents no longer in development. Antifungal agents currently in clinical trials include isavuconazole, albaconazole, SCY-078, VT-1161, and T-2307. Further data are needed to determine the role of these compounds in the treatment of candidemia and other forms of invasive candidiasis. The progressive reduction in antimicrobial drug development may result in a decline in antifungal drug discovery. Still there remains a critical need for new antifungal agents to treat and prevent invasive candidiasis and other life-threatening mycoses. PMID:25294098

Chitosan Loaded into a Hydrogel Delivery System as a Strategy to Treat Vaginal Co-Infection

PubMed Central

Perinelli, Diego R.; Bonacucina, Giulia; Cespi, Marco; Mastrotto, Francesca; Baffone, Wally; Casettari, Luca

2018-01-01

Polymeric hydrogels are common dosage forms designed for the topical administration of antimicrobial drugs to treat vaginal infections. One of the major advantages of using chitosan in these formulations is related to the intrinsic and broad antimicrobial activity exerted on bacteria and fungi by this natural polymer. Most vaginal yeast infections are caused by the pathogenic fungus Candida albicans. However, despite the anti-Candida activity towards and strains susceptibility to low molecular weight chitosan being documented, no information is available regarding the antimicrobial efficacy of mixed hydrogels in which chitosan is dispersed in a polymeric matrix. Therefore, the aim of the study is to evaluate the anti-Candida activity against eight different albicans and non-albicans strains of a mixed hydroxypropyl methylcellulose (HPMC)/chitosan hydrogel. Importantly, chitosan was dispersed in HPMC matrix either assembled in nanoparticles or in a monomolecular state to eventually correlate any variation in terms of rheological and mucoadhesive properties, as well as anti-Candida activity, with the chitosan form. Hydrogels containing 1% w/w chitosan, either as free polymer chain or assembled in nanoparticles, showed an improved mucoadhesiveness and an anti-Candida effect against all tested albicans and non-albicans strains. Overall, the results demonstrate the feasibility of preparing HPMC/CS mixed hydrogels intended for the prevention and treatment of Candida infections after vaginal administration. PMID:29401648

Evaluation of Genetic Diversity of Candida spp. and Klebsiella spp. Isolated from the Denture Plaque of COPD Patients.

PubMed

Przybyłowska, D; Piskorska, K; Gołaś, M; Sikora, M; Swoboda-Kopeć, E; Kostrzewa-Janicka, J; Mierzwińska-Nastalska, E

2017-01-01

Yeast-like fungi and gram-negative bacilli are the most frequent potential pathogens of the respiratory tract isolated from the denture plaque of patients with chronic obstructive pulmonary disease (COPD). Dominant species among yeast-like fungi are Candida albicans and Candida tropicalis. Significant frequency is also exhibited by Klebsiella pneumoniae and Klebsiella oxytoca. The purpose of this study was to analyze genetic diversity of the strains of C. albicans, C. tropicalis, and Klebsiella spp. present in patients in stable phases of COPD. The analysis was conducted by the random amplified polymorphic DNA (RAPD) method on clinical strains isolated from patients with COPD and control patients in overall good health. Forty one strains of Candida albicans, 12 of Candida tropicalis, as well as 9 strains of K. pneumoniae and 7 of K. oxytoca were scrutinized. The dominant species in clinical material from COPD patients was Candida albicans with a substantial degree of variations of genetic profiles. On the basis of affinity analysis, 19 genetic types were identified within this strain. An analysis of the banding patterns among C. tropicalis strains indicated the existence of 6 genetic types. A considerable diversity of genetic profiles among Klebsiella spp. also was established. The genotype diversity of Klebsiella spp. strains may indicate the endogenic character of the majority of infections, regardless of the therapy applied for the underlying condition.

[Influence of slime production and adhesion of Candida sp. on biofilm formation].

PubMed

Ciok-Pater, Emilia; Smolak, Przemysław; Wróblewska, Joanna; Gospodarek, Eugenia

2011-01-01

The increase of fungal infections in recent years is connected with the progress in medicine. The vast usage of biomaterials is an inseparable element of contemporary medicine but it also leads to development of infections. Yeast-like fungi Candida albicans are still the main pathogen of candidiasis. The ability to slime production and adhesion to polystyrene of Candida sp. on different surfaces can cause to form biofilm on surfaces of biomaterials used in production of catheters, drains and prosthesis. The aim of the study was to evaluate the influence of slime production and adhesion to polystyrene, of Candida sp. on biofilm formation on different biomaterials. 50 strains of Candida sp. were examined. They isolated from ill to Clinics of Anesthesiology and Intensive Therapy University Hospital No 1 of dr. A. Jurasza in Bydgoszcz. The ability to slime production was evaluated by Christensen method in modification Davenport and Branchini methods. The adhesion to polystyrene was evaluated by Richards et el method. The ability to produce biofilm biomaterials by the studied fungi was measured after 72 hours of incubation at 37 degrees C on different biomaterials. Yeast-like fungi Candida sp. fabricating slime and adhesion forming frequently biofilm on surface researched of biomaterials. Influence of chosen biological specificity ascertain on the ability to produce biofilm on surfaces of siliconized latex and polyvinylchloride.

Periorbital Necrotizing Fasciitis Secondary to Candida parapsilosis and Streptococcus pyogenes.

PubMed

Zhang, Matthew; Chelnis, James; Mawn, Louise A

Necrotizing fasciitis is most often caused by either polymicrobial bacterial infections or by Gram-positive organisms, such as Streptococcus or Staphylococcus; however, rare cases of fungal necrotizing fasciitis have been reported. Candida parapsilosis is an emerging fungal pathogen. This fungus grows in either a yeast or pseudohyphal form. C. parapsilosis has been reported to cause keratitis, intraocular infection, and seeding of frontalis slings. C. parapsilosis is a commensal of human skin and can be acquired by nosocomial spread. Necrotizing fasciitis due to Candida has rarely been reported, but to date C. parapsilosis has not been identified as the causative organism in necrotizing fasciitis. This is the first documented case of human periocular soft tissue infection by C. parapsilosis, and also the first report providing evidence of mycotic infection in a necrotizing fasciitis concurrently infected by Streptococcus pyogenes.

Understanding the Antifungal Mechanism of Ag@ZnO Core-shell Nanocomposites against Candida krusei.

PubMed

Das, Bhaskar; Khan, Md Imran; Jayabalan, R; Behera, Susanta K; Yun, Soon-Il; Tripathy, Suraj K; Mishra, Amrita

2016-11-04

In the present paper, facile synthesis of Ag@ZnO core-shell nanocomposites is reported where zinc oxide is coated on biogenic silver nanoparticles synthesized using Andrographis paniculata and Aloe vera leaf extract. Structural features of as synthesized nanocomposites are characterized by UV-visible spectroscopy, XRD, and FTIR. Morphology of the above core-shell nanocomposites is investigated by electron microscopy. As synthesized nanocomposite material has shown antimicrobial activity against Candida krusei, which is an opportunistic pathogen known to cause candidemia. The possible mode of activity of the above material has been studied by in-vitro molecular techniques. Our investigations have shown that surface coating of biogenic silver nanoparticles by zinc oxide has increased its antimicrobial efficiency against Candida krusei, while decreasing its toxicity towards A431 human epidermoid carcinoma cell lines.

Calcineurin is required for pseudohyphal growth, virulence, and drug resistance in Candida lusitaniae.

PubMed

Zhang, Jing; Silao, Fitz Gerald S; Bigol, Ursela G; Bungay, Alice Alma C; Nicolas, Marilou G; Heitman, Joseph; Chen, Ying-Lien

2012-01-01

Candida lusitaniae is an emerging fungal pathogen that infects immunocompromised patients including HIV/AIDS, cancer, and neonatal pediatric patients. Though less prevalent than other Candida species, C. lusitaniae is unique in its ability to develop resistance to amphotericin B. We investigated the role of the calcium-activated protein phosphatase calcineurin in several virulence attributes of C. lusitaniae including pseudohyphal growth, serum survival, and growth at 37°C. We found that calcineurin and Crz1, a C. albicans Crz1 homolog acting as a downstream target of calcineurin, are required for C. lusitaniae pseudohyphal growth, a process for which the underlying mechanism remains largely unknown in C. lusitaniae but hyphal growth is fundamental to C. albicans virulence. We demonstrate that calcineurin is required for cell wall integrity, ER stress response, optimal growth in serum, virulence in a murine systemic infection model, and antifungal drug tolerance in C. lusitaniae. To further examine the potential of targeting the calcineurin signaling cascade for antifungal drug development, we examined the activity of a calcineurin inhibitor FK506 in combination with caspofungin against echinocandin resistant C. lusitaniae clinical isolates. Broth microdilution and drug disk diffusion assays demonstrate that FK506 has synergistic fungicidal activity with caspofungin against echinocandin resistant isolates. Our findings reveal that pseudohyphal growth is controlled by the calcineurin signaling cascade, and highlight the potential use of calcineurin inhibitors and caspofungin for emerging drug-resistant C. lusitaniae infections.

Calcineurin Is Required for Pseudohyphal Growth, Virulence, and Drug Resistance in Candida lusitaniae

PubMed Central

Zhang, Jing; Silao, Fitz Gerald S.; Bigol, Ursela G.; Bungay, Alice Alma C.; Nicolas, Marilou G.; Heitman, Joseph; Chen, Ying-Lien

2012-01-01

Candida lusitaniae is an emerging fungal pathogen that infects immunocompromised patients including HIV/AIDS, cancer, and neonatal pediatric patients. Though less prevalent than other Candida species, C. lusitaniae is unique in its ability to develop resistance to amphotericin B. We investigated the role of the calcium-activated protein phosphatase calcineurin in several virulence attributes of C. lusitaniae including pseudohyphal growth, serum survival, and growth at 37°C. We found that calcineurin and Crz1, a C. albicans Crz1 homolog acting as a downstream target of calcineurin, are required for C. lusitaniae pseudohyphal growth, a process for which the underlying mechanism remains largely unknown in C. lusitaniae but hyphal growth is fundamental to C. albicans virulence. We demonstrate that calcineurin is required for cell wall integrity, ER stress response, optimal growth in serum, virulence in a murine systemic infection model, and antifungal drug tolerance in C. lusitaniae. To further examine the potential of targeting the calcineurin signaling cascade for antifungal drug development, we examined the activity of a calcineurin inhibitor FK506 in combination with caspofungin against echinocandin resistant C. lusitaniae clinical isolates. Broth microdilution and drug disk diffusion assays demonstrate that FK506 has synergistic fungicidal activity with caspofungin against echinocandin resistant isolates. Our findings reveal that pseudohyphal growth is controlled by the calcineurin signaling cascade, and highlight the potential use of calcineurin inhibitors and caspofungin for emerging drug-resistant C. lusitaniae infections. PMID:22952924

Acanthamoeba: An Overview of the Challenges to the Development of a Consensus Methodology of Disinfection Efficacy Testing for Contact Lens Care Products.

PubMed

Brocious, Jeffrey; Tarver, Michelle E; Hampton, Denise; Eydelman, Malvina

2018-04-24

With the increasing incidence of more pathogens that can cause microbial keratitis (MK), it is necessary to periodically reassess disinfection multipurpose solutions testing requirements to ensure that relevant organisms to challenge them are being used. Current testing protocols have included common pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, Candida albicans, and Fusarium solani but have omitted less common pathogens such as Acanthamoeba. Specifically, Acanthamoeba sp. has recently been identified as a prevalent cause of MK in certain countries. Developing an appropriate protocol for this unique organism presents a challenge, given its two distinct life stages, methods to grow the organism, encystment techniques, and many other parameters that can affect testing outcomes. Therefore, the appropriate combination of these parameters is crucial to developing a protocol that ensures consistent, accurate results. The FDA has recognized the importance of establishing a standardized testing protocol for this pathogen and embarked on research efforts to provide a recommended testing protocol for testing contact lens care products.

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.

Potential Role for a Carbohydrate Moiety in Anti-Candida Activity of Human Oral Epithelial Cells

PubMed Central

Steele, Chad; Leigh, Janet; Swoboda, Rolf; Ozenci, Hatice; Fidel, Paul L.

2001-01-01

Candida albicans is both a commensal and a pathogen at the oral mucosa. Although an intricate network of host defense mechanisms are expected for protection against oropharyngeal candidiasis, anti-Candida host defense mechanisms at the oral mucosa are poorly understood. Our laboratory recently showed that primary epithelial cells from human oral mucosa, as well as an oral epithelial cell line, inhibit the growth of blastoconidia and/or hyphal phases of several Candida species in vitro with a requirement for cell contact and with no demonstrable role for soluble factors. In the present study, we show that oral epithelial cell-mediated anti-Candida activity is resistant to gamma-irradiation and is not mediated by phagocytosis, nitric oxide, hydrogen peroxide, and superoxide oxidative inhibitory pathways or by nonoxidative components such as soluble defensin and calprotectin peptides. In contrast, epithelial cell-mediated anti-Candida activity was sensitive to heat, paraformaldehyde fixation, and detergents, but these treatments were accompanied by a significant loss in epithelial cell viability. Treatments that removed existing membrane protein or lipid moieties in the presence or absence of protein synthesis inhibitors had no effect on epithelial cell inhibitory activity. In contrast, the epithelial cell-mediated anti-Candida activity was abrogated after treatment of the epithelial cells with periodic acid, suggesting a role for carbohydrates. Adherence of C. albicans to oral epithelial cells was unaffected, indicating that the carbohydrate moiety is exclusively associated with the growth inhibition activity. Subsequent studies that evaluated specific membrane carbohydrate moieties, however, showed no role for sulfated polysaccharides, sialic acid residues, or glucose- and mannose-containing carbohydrates. These results suggest that oral epithelial cell-mediated anti-Candida activity occurs exclusively with viable epithelial cells through contact with C. albicans by an as-yet-undefined carbohydrate moiety. PMID:11598085

In Vitro and In Vivo Activity of a Novel Antifungal Small Molecule against Candida Infections

PubMed Central

Yuen, Kwok Yong; Wang, Yu; Yang, Dan; Samaranayake, Lakshman Perera

2014-01-01

Candida is the most common fungal pathogen of humans worldwide and has become a major clinical problem because of the growing number of immunocompromised patients, who are susceptible to infection. Moreover, the number of available antifungals is limited, and antifungal-resistant Candida strains are emerging. New and effective antifungals are therefore urgently needed. Here, we discovered a small molecule with activity against Candida spp. both in vitro and in vivo. We screened a library of 50,240 small molecules for inhibitors of yeast-to-hypha transition, a major virulence attribute of Candida albicans. This screening identified 20 active compounds. Further examination of the in vitro antifungal and anti-biofilm properties of these compounds, using a range of Candida spp., led to the discovery of SM21, a highly potent antifungal molecule (minimum inhibitory concentration (MIC) 0.2 – 1.6 µg/ml). In vitro, SM21 was toxic to fungi but not to various human cell lines or bacterial species and was active against Candida isolates that are resistant to existing antifungal agents. Moreover, SM21 was relatively more effective against biofilms of Candida spp. than the current antifungal agents. In vivo, SM21 prevented the death of mice in a systemic candidiasis model and was also more effective than the common antifungal nystatin at reducing the extent of tongue lesions in a mouse model of oral candidiasis. Propidium iodide uptake assay showed that SM21 affected the integrity of the cell membrane. Taken together, our results indicate that SM21 has the potential to be developed as a novel antifungal agent for clinical use. PMID:24465737

Immune recovery in HIV-infected patients after Candida esophagitis is impaired despite long-term antiretroviral therapy

PubMed Central

Stuehler, Claudia; Bernardini, Claudia; Elzi, Luigia; Stoeckle, Marcel; Zimmerli, Stefan; Furrer, Hansjakob; Günthard, Huldrych F.; Leibundgut-Landmann, Salomé; Battegay, Manuel; Khanna, Nina

2016-01-01

Objective: Candida esophagitis belongs to the most common AIDS-defining diseases; however, a comprehensive immune pathogenic concept is lacking. Design: We investigated the immune status of 37 HIV-1-infected patients from the Swiss HIV cohort study at diagnosis of Candida esophagitis, 1 year before, 1 year later and after 2 years of suppressed HIV RNA. We compared these patients with three groups: 37 HIV-1-infected patients without Candida esophagitis but similar CD4+ cell counts as the patients at diagnosis (advanced HIV group), 15 HIV-1-infected patients with CD4+ cell counts higher than 500 cells/μl, CD4+ cell nadirs higher than 350 cells/μl and suppressed HIV RNA under combination antiretroviral therapy (cART) (early cART group) and 20 healthy individuals. Methods: We investigated phenotype, cytokine production and proliferative capacity of different immune cells by flow cytometry and enzyme-linked immunosorbent spot. Results: We found that patients with Candida esophagitis had nearly abolished CD4+ cell proliferation in response to Candida albicans, significantly increased percentages of dysfunctional CD4+ cells, significantly decreased cytotoxic natural killer cell counts and peripheral innate lymphoid cell counts and significantly reduced IFN-γ and IL-17 production compared with the early cART group and healthy individuals. Most of these defects remained for more than 2 years despite viral suppression. The advanced HIV group without opportunistic infection showed partly improved immune recovery. Conclusion: Our data indicate that Candida esophagitis in HIV-1-infected patients is caused by an accumulation of multiple, partly Candida-specific immunological defects. Long-term immune recovery is impaired, illustrating that specific immunological gaps persist despite cART. These data also support the rationale for early cART initiation to prevent irreversible immune defects. PMID:27149086

Applying Convergent Immunity to Innovative Vaccines Targeting Staphylococcus aureus

PubMed Central

Yeaman, Michael R.; Filler, Scott G.; Schmidt, Clint S.; Ibrahim, Ashraf S.; Edwards, John E.; Hennessey, John P.

2014-01-01

Recent perspectives forecast a new paradigm for future “third generation” vaccines based on commonalities found in diverse pathogens or convergent immune defenses to such pathogens. For Staphylococcus aureus, recurring infections and a limited success of vaccines containing S. aureus antigens imply that native antigens induce immune responses insufficient for optimal efficacy. These perspectives exemplify the need to apply novel vaccine strategies to high-priority pathogens. One such approach can be termed convergent immunity, where antigens from non-target organisms that contain epitope homologs found in the target organism are applied in vaccines. This approach aims to evoke atypical immune defenses via synergistic processes that (1) afford protective efficacy; (2) target an epitope from one organism that contributes to protective immunity against another; (3) cross-protect against multiple pathogens occupying a common anatomic or immunological niche; and/or (4) overcome immune subversion or avoidance strategies of target pathogens. Thus, convergent immunity has a potential to promote protective efficacy not usually elicited by native antigens from a target pathogen. Variations of this concept have been mainstays in the history of viral and bacterial vaccine development. A more far-reaching example is the pre-clinical evidence that specific fungal antigens can induce cross-kingdom protection against bacterial pathogens. This trans-kingdom protection has been demonstrated in pre-clinical studies of the recombinant Candida albicans agglutinin-like sequence 3 protein (rAls3) where it was shown that a vaccine containing rAls3 provides homologous protection against C. albicans, heterologous protection against several other Candida species, and convergent protection against several strains of S. aureus. Convergent immunity reflects an intriguing new approach to designing and developing vaccine antigens and is considered here in the context of vaccines to target S. aureus. PMID:25309545

Potential Targets for Antifungal Drug Discovery Based on Growth and Virulence in Candida albicans

PubMed Central

Li, Xiuyun; Hou, Yinglong; Yue, Longtao; Liu, Shuyuan; Du, Juan

2015-01-01

Fungal infections, especially infections caused by Candida albicans, remain a challenging problem in clinical settings. Despite the development of more-effective antifungal drugs, their application is limited for various reasons. Thus, alternative treatments with drugs aimed at novel targets in C. albicans are needed. Knowledge of growth and virulence in fungal cells is essential not only to understand their pathogenic mechanisms but also to identify potential antifungal targets. This article reviews the current knowledge of the mechanisms of growth and virulence in C. albicans and examines potential targets for the development of new antifungal drugs. PMID:26195510

Tenebrio molitor (Coleoptera: Tenebrionidae) as an alternative host to study fungal infections.

PubMed

de Souza, Patrícia Canteri; Morey, Alexandre Tadachi; Castanheira, Gabriel Marcondes; Bocate, Karla Paiva; Panagio, Luciano Aparecido; Ito, Fabio Augusto; Furlaneto, Márcia Cristina; Yamada-Ogatta, Sueli Fumie; Costa, Idessânia Nazareth; Mora-Montes, Hector Manuel; Almeida, Ricardo Sergio

2015-11-01

Models of host–pathogen interactions are crucial for the analysis of microbial pathogenesis. In this context, invertebrate hosts, including Drosophila melanogaster (fruit fly), Caenorhabditis elegans (nematode) and Galleria mellonella (moth), have been used to study the pathogenesis of fungi and bacteria. Each of these organisms offers distinct benefits in elucidating host–pathogen interactions. In this study,we present a newinvertebrate infection model to study fungal infections: the Tenebrio molitor (beetle) larvae. Here we performed T. molitor larvae infection with one of two important fungal human pathogens, Candida albicans or Cryptococcus neoformans, and analyzed survival curves and larva infected tissues.We showed that increasing concentrations of inoculum of both fungi resulted in increased mortality rates, demonstrating the efficiency of the method to evaluate the virulence of pathogenic yeasts. Additionally, following 12 h post-infection, C. albicans formsmycelia, spreading its hyphae through the larva tissue,whilst GMS stain enabled the visualization of C. neoformans yeast and theirmelanin capsule. These larvae are easier to cultivate in the laboratory than G. mellonella larvae, and offer the same benefits. Therefore, this insect model could be a useful alternative tool to screen clinical pathogenic yeast strainswith distinct virulence traits or different mutant strains.

Effects of hemin, CO2, and pH on the branching of Candida albicans filamentous forms.

PubMed

Jakab, Ágnes; Antal, Károly; Emri, Tamás; Boczonádi, Imre; Imre, Alexandra; Gebri, Enikő; Majoros, László; Pfliegler, Walter Péter; Szarka, Máté; Balla, György; Balla, József; Pócsi, István

2016-12-01

Morphological transitions of wild-type and oxidative stress-tolerant Candida albicans strains were followed in the RPMI-FBS culture medium at pH values and CO 2 levels characteristic for the anatomical niches inhabited by this opportunistic human pathogen fungus, including the oral cavity as well as the intestinal and vaginal lumens. Selected cultures were also supplemented with hemin modeling bleedings. Germination as well as elongation and branching of hyphae were monitored in the cultures using time-lapse video microscopy. Unexpectedly, branching time, which is defined as the time taken until the first branch of hypha emerges for the first time after germination, correlated well with alterations in the environmental conditions meanwhile no such correlations were found for germination time (time lasted until the appearance of the germination tube). Based on these observations, hypotheses were set up to estimate the significance of branching time in the pathogenesis of both superficial and systemic candidiases.

The evolution of drug resistance in clinical isolates of Candida albicans

PubMed Central

Guiducci, Candace; Martinez, Diego A; Delorey, Toni; Li, Bi yu; White, Theodore C; Cuomo, Christina; Rao, Reeta P; Berman, Judith; Thompson, Dawn A; Regev, Aviv

2015-01-01

Candida albicans is both a member of the healthy human microbiome and a major pathogen in immunocompromised individuals. Infections are typically treated with azole inhibitors of ergosterol biosynthesis often leading to drug resistance. Studies in clinical isolates have implicated multiple mechanisms in resistance, but have focused on large-scale aberrations or candidate genes, and do not comprehensively chart the genetic basis of adaptation. Here, we leveraged next-generation sequencing to analyze 43 isolates from 11 oral candidiasis patients. We detected newly selected mutations, including single-nucleotide polymorphisms (SNPs), copy-number variations and loss-of-heterozygosity (LOH) events. LOH events were commonly associated with acquired resistance, and SNPs in 240 genes may be related to host adaptation. Conversely, most aneuploidies were transient and did not correlate with drug resistance. Our analysis also shows that isolates also varied in adherence, filamentation, and virulence. Our work reveals new molecular mechanisms underlying the evolution of drug resistance and host adaptation. DOI: http://dx.doi.org/10.7554/eLife.00662.001 PMID:25646566

Genomic identification of potential targets unique to Candida albicans for the discovery of antifungal agents.

PubMed

Tripathi, Himanshu; Luqman, Suaib; Meena, Abha; Khan, Feroz

2014-01-01

Despite of modern antifungal therapy, the mortality rates of invasive infection with human fungal pathogen Candida albicans are up to 40%. Studies suggest that drug resistance in the three most common species of human fungal pathogens viz., C. albicans, Aspergillus fumigatus (causing mortality rate up to 90%) and Cryptococcus neoformans (causing mortality rate up to 70%) is due to mutations in the target enzymes or high expression of drug transporter genes. Drug resistance in human fungal pathogens has led to an imperative need for the identification of new targets unique to fungal pathogens. In the present study, we have used a comparative genomics approach to find out potential target proteins unique to C. albicans, an opportunistic fungus responsible for severe infection in immune-compromised human. Interestingly, many target proteins of existing antifungal agents showed orthologs in human cells. To identify unique proteins, we have compared proteome of C. albicans [SC5314] i.e., 14,633 total proteins retrieved from the RefSeq database of NCBI, USA with proteome of human and non-pathogenic yeast Saccharomyces cerevisiae. Results showed that 4,568 proteins were identified unique to C. albicans as compared to those of human and later when these unique proteins were compared with S. cerevisiae proteome, finally 2,161 proteins were identified as unique proteins and after removing repeats total 1,618 unique proteins (42 functionally known, 1,566 hypothetical and 10 unknown) were selected as potential antifungal drug targets unique to C. albicans.

A novel role of the ferric reductase Cfl1 in cell wall integrity, mitochondrial function, and invasion to host cells in Candida albicans.

PubMed

Yu, Qilin; Dong, Yijie; Xu, Ning; Qian, Kefan; Chen, Yulu; Zhang, Biao; Xing, Laijun; Li, Mingchun

2014-11-01

Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases. Iron acquisition is an important factor for pathogen-host interaction and also a significant element for the pathogenicity of this organism. Ferric reductases, which convert ferric iron into ferrous iron, are important components of the high-affinity iron uptake system. Sequence analyses have identified at least 17 putative ferric reductase genes in C. albicans genome. CFL1 was the first ferric reductase identified in C. albicans. However, little is known about its roles in C. albicans physiology and pathogenicity. In this study, we found that disruption of CFL1 led to hypersensitivity to chemical and physical cell wall stresses, activation of the cell wall integrity (CWI) pathway, abnormal cell wall composition, and enhanced secretion, indicating a defect in CWI in this mutant. Moreover, this mutant showed abnormal mitochondrial activity and morphology, suggesting a link between ferric reductases and mitochondrial function. In addition, this mutant displayed decreased ability of adhesion to both the polystyrene microplates and buccal epithelial cells and invasion of host epithelial cells. These findings revealed a novel role of C. albicans Cfl1 in maintenance of CWI, mitochondrial function, and interaction between this pathogen and the host. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Oral and dental infections with anaerobic bacteria: clinical features, predominant pathogens, and treatment.

PubMed

Tanner, A; Stillman, N

1993-06-01

Microbial populations colonizing the teeth are a major source of pathogens responsible for oral and dental infections, including periodontal diseases, gingivitis, pericoronitis, endodontitis, peri-implantitis, and postextraction infections. Each entity has distinct clinical and microbial features. Bacterial species associated with oral infections include Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Campylobacter rectus, Eubacterium species, Fusobacterium nucleatum, Eikenella corrodens, and Peptostreptococcus micros. Treponema pallidum-related spirochetes have been associated with acute necrotizing ulcerative gingivitis. Porphyromonas endodontalis appears to be specifically related to endodontic infections. Oral infections in medically compromised patients, including those with AIDS, are associated with similar species and are usually complicated by superinfection with enteric and Candida species. Isolation of species causing oral infections requires the collection of appropriate samples and the use of strictly anaerobic techniques. Rapid selective culture, immunofluorescence, and DNA probe methods have been developed for the identification of these oral species. The varied measures required in the management of oral and dental infections may include antimicrobial therapy. Accurate microbiological diagnosis, including antibiotic susceptibility testing, is indicated for cases that do not respond to therapy.

Evaluation of Microbial Load in Oropharyngeal Mucosa from Tannery Workers

PubMed Central

Castellanos-Arévalo, Diana C.; Castellanos-Arévalo, Andrea P.; Camarena-Pozos, David A.; Colli-Mull, Juan G.; Maldonado-Vega, María

2014-01-01

Background Animal skin provides an ideal medium for the propagation of microorganisms and it is used like raw material in the tannery and footware industry. The aim of this study was to evaluate and identify the microbial load in oropharyngeal mucosa of tannery employees. Methods The health risk was estimated based on the identification of microorganisms found in the oropharyngeal mucosa samples. The study was conducted in a tanners group and a control group. Samples were taken from oropharyngeal mucosa and inoculated on plates with selective medium. In the samples, bacteria were identified by 16S ribosomal DNA analysis and the yeasts through a presumptive method. In addition, the sensitivity of these microorganisms to antibiotics/antifungals was evaluated. Results The identified bacteria belonged to the families Enterobacteriaceae, Pseudomonadaceae, Neisseriaceae, Alcaligenaceae, Moraxellaceae, and Xanthomonadaceae, of which some species are considered as pathogenic or opportunistic microorganisms; these bacteria were not present in the control group. Forty-two percent of bacteria identified in the tanners group are correlated with respiratory diseases. Yeasts were also identified, including the following species: Candida glabrata, Candida tropicalis, Candida albicans, and Candida krusei. Regarding the sensitivity test of bacteria identified in the tanners group, 90% showed sensitivity to piperacillin/tazobactam, 87% showed sensitivity to ticarcillin/clavulanic acid, 74% showed sensitivity to ampicillin/sulbactam, and 58% showed sensitivity to amoxicillin/clavulanic acid. Conclusion Several of the bacteria and yeast identified in the oropharyngeal mucosa of tanners have been correlated with infections in humans and have already been reported as airborne microorganisms in this working environment, representing a health risk for workers. PMID:25830072

Structural and Functional Elucidation of Yeast Lanosterol 14α-Demethylase in Complex with Agrochemical Antifungals

PubMed Central

Sagatova, Alia A.; Keniya, Mikhail V.; Negroni, Jacopo; Wilson, Rajni K.; Woods, Matthew A.; Monk, Brian C.

2016-01-01

Azole antifungals, known as demethylase inhibitors (DMIs), target sterol 14α-demethylase (CYP51) in the ergosterol biosynthetic pathway of fungal pathogens of both plants and humans. DMIs remain the treatment of choice in crop protection against a wide range of fungal phytopathogens that have the potential to reduce crop yields and threaten food security. We used a yeast membrane protein expression system to overexpress recombinant hexahistidine-tagged S. cerevisiae lanosterol 14α-demethylase and the Y140F or Y140H mutants of this enzyme as surrogates in order characterize interactions with DMIs. The whole-cell antifungal activity (MIC50 values) of both the R- and S-enantiomers of tebuconazole, prothioconazole (PTZ), prothioconazole-desthio, and oxo-prothioconazole (oxo-PTZ) as well as for fluquinconazole, prochloraz and a racemic mixture of difenoconazole were determined. In vitro binding studies with the affinity purified enzyme were used to show tight type II binding to the yeast enzyme for all compounds tested except PTZ and oxo-PTZ. High resolution X-ray crystal structures of ScErg11p6×His in complex with seven DMIs, including four enantiomers, reveal triazole-mediated coordination of all compounds and the specific orientation of compounds within the relatively hydrophobic binding site. Comparison with CYP51 structures from fungal pathogens including Candida albicans, Candida glabrata and Aspergillus fumigatus provides strong evidence for a highly conserved CYP51 structure including the drug binding site. The structures obtained using S. cerevisiae lanosterol 14α-demethylase in complex with these agrochemicals provide the basis for understanding the impact of mutations on azole susceptibility and a platform for the structure-directed design of the next-generation of DMIs. PMID:27907120

Host carbon sources modulate cell wall architecture, drug resistance and virulence in a fungal pathogen

PubMed Central

Ene, Iuliana V; Adya, Ashok K; Wehmeier, Silvia; Brand, Alexandra C; MacCallum, Donna M; Gow, Neil A R; Brown, Alistair J P

2012-01-01

The survival of all microbes depends upon their ability to respond to environmental challenges. To establish infection, pathogens such as Candida albicans must mount effective stress responses to counter host defences while adapting to dynamic changes in nutrient status within host niches. Studies of C. albicans stress adaptation have generally been performed on glucose-grown cells, leaving the effects of alternative carbon sources upon stress resistance largely unexplored. We have shown that growth on alternative carbon sources, such as lactate, strongly influence the resistance of C. albicans to antifungal drugs, osmotic and cell wall stresses. Similar trends were observed in clinical isolates and other pathogenic Candida species. The increased stress resistance of C. albicans was not dependent on key stress (Hog1) and cell integrity (Mkc1) signalling pathways. Instead, increased stress resistance was promoted by major changes in the architecture and biophysical properties of the cell wall. Glucose- and lactate-grown cells displayed significant differences in cell wall mass, ultrastructure, elasticity and adhesion. Changes in carbon source also altered the virulence of C. albicans in models of systemic candidiasis and vaginitis, confirming the importance of alternative carbon sources within host niches during C. albicans infections. PMID:22587014

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

Genetic and phenotypic intra-species variation in Candida albicans.

PubMed

Hirakawa, Matthew P; Martinez, Diego A; Sakthikumar, Sharadha; Anderson, Matthew Z; Berlin, Aaron; Gujja, Sharvari; Zeng, Qiandong; Zisson, Ethan; Wang, Joshua M; Greenberg, Joshua M; Berman, Judith; Bennett, Richard J; Cuomo, Christina A

2015-03-01

Candida albicans is a commensal fungus of the human gastrointestinal tract and a prevalent opportunistic pathogen. To examine diversity within this species, extensive genomic and phenotypic analyses were performed on 21 clinical C. albicans isolates. Genomic variation was evident in the form of polymorphisms, copy number variations, chromosomal inversions, subtelomeric hypervariation, loss of heterozygosity (LOH), and whole or partial chromosome aneuploidies. All 21 strains were diploid, although karyotypic changes were present in eight of the 21 isolates, with multiple strains being trisomic for Chromosome 4 or Chromosome 7. Aneuploid strains exhibited a general fitness defect relative to euploid strains when grown under replete conditions. All strains were also heterozygous, yet multiple, distinct LOH tracts were present in each isolate. Higher overall levels of genome heterozygosity correlated with faster growth rates, consistent with increased overall fitness. Genes with the highest rates of amino acid substitutions included many cell wall proteins, implicating fast evolving changes in cell adhesion and host interactions. One clinical isolate, P94015, presented several striking properties including a novel cellular phenotype, an inability to filament, drug resistance, and decreased virulence. Several of these properties were shown to be due to a homozygous nonsense mutation in the EFG1 gene. Furthermore, loss of EFG1 function resulted in increased fitness of P94015 in a commensal model of infection. Our analysis therefore reveals intra-species genetic and phenotypic differences in C. albicans and delineates a natural mutation that alters the balance between commensalism and pathogenicity. © 2015 Hirakawa et al.; Published by Cold Spring Harbor Laboratory Press.

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.

Candida Infections and Human Defensins.

PubMed

Polesello, Vania; Segat, Ludovica; Crovella, Sergio; Zupin, Luisa

2017-01-01

Candida species infections are an important worldwide health issue since they do not only affect immunocompromised patients but also healthy individuals. The host developed different mechanisms of protection against Candida infections; specifically the immune system and the innate immune response are the first line of defence. Defensis are a group of antimicrobial peptides, components of the innate immunity, produced at mucosal level and known to be active against bacteria, virus but also fungi. The aim of the current work was to review all previous studies in literature that analysed defensins in the context of Candida spp. infections, in order to investigate and clarify the exact mechanisms of defensins anti-fungal action. Several studies were identified from 1985 to 2017 (9 works form years 1985 to 1999, 44 works ranging from 2000 to 2009 and 35 from 2010 to 2017) searched in two electronic databases (PubMed and Google Scholar). The main key words used for the research were "Candida", "Defensins"," Innate immune system","fungi". The findings of the reviewed studies highlight the pivotal role of defensins antimicrobial peptides in the immune response against Candida infections, since they are able to discriminate host cell from fungi: defensins are able to recognize the pathogens cell wall (different in composition from the human ones), and to disrupt it through membrane permeabilization. However, further research is needed to explain completely defensins' mechanisms of action to fight C. albicans (and other Candida spp.) infections, being the information fragmentary and only in part elucidated. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Repeat-Associated Fission Yeast-Like Regional Centromeres in the Ascomycetous Budding Yeast Candida tropicalis

PubMed Central

Chatterjee, Gautam; Sankaranarayanan, Sundar Ram; Guin, Krishnendu; Thattikota, Yogitha; Padmanabhan, Sreedevi; Siddharthan, Rahul; Sanyal, Kaustuv

2016-01-01

The centromere, on which kinetochore proteins assemble, ensures precise chromosome segregation. Centromeres are largely specified by the histone H3 variant CENP-A (also known as Cse4 in yeasts). Structurally, centromere DNA sequences are highly diverse in nature. However, the evolutionary consequence of these structural diversities on de novo CENP-A chromatin formation remains elusive. Here, we report the identification of centromeres, as the binding sites of four evolutionarily conserved kinetochore proteins, in the human pathogenic budding yeast Candida tropicalis. Each of the seven centromeres comprises a 2 to 5 kb non-repetitive mid core flanked by 2 to 5 kb inverted repeats. The repeat-associated centromeres of C. tropicalis all share a high degree of sequence conservation with each other and are strikingly diverged from the unique and mostly non-repetitive centromeres of related Candida species—Candida albicans, Candida dubliniensis, and Candida lusitaniae. Using a plasmid-based assay, we further demonstrate that pericentric inverted repeats and the underlying DNA sequence provide a structural determinant in CENP-A recruitment in C. tropicalis, as opposed to epigenetically regulated CENP-A loading at centromeres in C. albicans. Thus, the centromere structure and its influence on de novo CENP-A recruitment has been significantly rewired in closely related Candida species. Strikingly, the centromere structural properties along with role of pericentric repeats in de novo CENP-A loading in C. tropicalis are more reminiscent to those of the distantly related fission yeast Schizosaccharomyces pombe. Taken together, we demonstrate, for the first time, fission yeast-like repeat-associated centromeres in an ascomycetous budding yeast. PMID:26845548

Evaluation of a new T2 Magnetic Resonance assay for rapid detection of emergent fungal pathogen Candida auris on clinical skin swab samples.

PubMed

Sexton, D Joseph; Bentz, Meghan L; Welsh, Rory M; Litvintseva, Anastasia P

2018-06-25

Candida auris is a multidrug-resistant pathogenic yeast whose recent emergence is of increasing public-health concern. C. auris can colonize multiple body sites, including patients' skin, and survive for weeks in the healthcare environment, facilitating patient-to-patient transmission and fueling healthcare-associated outbreaks. Rapid and accurate detection of C. auris colonization is essential for timely implementation of infection control measures and prevent transmission. Currently, axilla/groin composite swabs, used to assess colonization status, are processed using a culture-based method that is sensitive and specific but requires 14 days. This delay limits the opportunity to respond and highlights the need for a faster alternative. The culture-independent T2 Magnetic Resonance (T2MR) system is a rapid diagnostic platform shown to detect target pathogens of interest from unprocessed blood samples in <5 hours. In this study, a new C. auris-specific T2 assay was evaluated for screening of the skin surveillance samples. Inclusivity and limit of detection of the T2 C. auris assay were assessed with spiked samples in a representative skin flora background. The T2 C. auris assay recognized isolates from each of the 4 known clades of C. auris and consistently detected cells at 5 CFU/mL. Finally, 89 clinical axilla/groin swab samples were processed with the T2 C. auris assay. The culture-based diagnostic assay was used as a gold standard to determine performance statistics including sensitivity (0.89) and specificity (0.98). Overall, the T2 C. auris assay performed well as a rapid diagnostic and could help expedite the detection of C. auris in patient skin swabs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Diorcinol D Exerts Fungicidal Action against Candida albicans through Cytoplasm Membrane Destruction and ROS Accumulation

PubMed Central

Li, Ying; Chang, Wenqiang; Zhang, Ming; Li, Xiaobin; Jiao, Yang; Lou, Hongxiang

2015-01-01

Candida albicans, which is the most common human fungal pathogen, causes high mortality among immunocompromised patients. Antifungal drug resistance becomes a major challenge for the management of Candida infection. Diorcinol D (DD), a diphenyl ether derivative isolated from an endolichenic fungus, exerted fungicidal action against Candida species. In this study, we investigated the possible mechanism of its antifungal activity. The change of membrane dynamics and permeability suggested that the cell membrane was disrupted by the treatment of DD. This was further supported by the evidences of intracellular glycerol accumulation, alteration of cell ultrastructure, and down-regulation of genes involved in cell membrane synthesis. In addition, the treatment of C. albicans with DD resulted in the elevation of reactive oxygen species (ROS), which caused the dysfunction of mitochondria. These altogether suggested that DD exerted its antifungal activity through cytoplasmic membrane destruction and ROS accumulation. This finding is helpful to uncover the underlying mechanisms for the diphenyl ether derivatives and provides a potential application in fighting clinical fungal infections. PMID:26047493

Conservation and Divergence in the Candida Species Biofilm Matrix Mannan-Glucan Complex Structure, Function, and Genetic Control.

PubMed

Dominguez, Eddie; Zarnowski, Robert; Sanchez, Hiram; Covelli, Antonio S; Westler, William M; Azadi, Parastoo; Nett, Jeniel; Mitchell, Aaron P; Andes, David R

2018-04-03

Candida biofilms resist the effects of available antifungal therapies. Prior studies with Candida albicans biofilms show that an extracellular matrix mannan-glucan complex (MGCx) contributes to antifungal sequestration, leading to drug resistance. Here we implement biochemical, pharmacological, and genetic approaches to explore a similar mechanism of resistance for the three most common clinically encountered non- albicans Candida species (NAC). Our findings reveal that each Candida species biofilm synthesizes a mannan-glucan complex and that the antifungal-protective function of this complex is conserved. Structural similarities extended primarily to the polysaccharide backbone (α-1,6-mannan and β-1,6-glucan). Surprisingly, biochemical analysis uncovered stark differences in the branching side chains of the MGCx among the species. Consistent with the structural analysis, similarities in the genetic control of MGCx production for each Candida species also appeared limited to the synthesis of the polysaccharide backbone. Each species appears to employ a unique subset of modification enzymes for MGCx synthesis, likely accounting for the observed side chain diversity. Our results argue for the conservation of matrix function among Candida spp. While biogenesis is preserved at the level of the mannan-glucan complex backbone, divergence emerges for construction of branching side chains. Thus, the MGCx backbone represents an ideal drug target for effective pan- Candida species biofilm therapy. IMPORTANCE Candida species, the most common fungal pathogens, frequently grow as a biofilm. These adherent communities tolerate extremely high concentrations of antifungal agents, due in large part, to a protective extracellular matrix. The present studies define the structural, functional, and genetic similarities and differences in the biofilm matrix from the four most common Candida species. Each species synthesizes an extracellular mannan-glucan complex (MGCx) which contributes to sequestration of antifungal drug, shielding the fungus from this external assault. Synthesis of a common polysaccharide backbone appears conserved. However, subtle structural differences in the branching side chains likely rely upon unique modification enzymes, which are species specific. Our findings identify MGCx backbone synthesis as a potential pan- Candida biofilm therapeutic target. Copyright © 2018 Dominguez et al.

Prunus mume extract exhibits antimicrobial activity against pathogenic oral bacteria.

PubMed

Seneviratne, Chamida J; Wong, Ricky W K; Hägg, Urban; Chen, Yong; Herath, Thanuja D K; Samaranayake, P Lakshman; Kao, Richard

2011-07-01

Prunus mume is a common fruit in Asia, which has been used in traditional Chinese medicine. In this study, we focused on the antimicrobial properties of Prunus mume extract against oral pathogens related to dental caries and periodontal diseases. A total of 15 oral pathogens including Streptococcus mutans, S. sobrinus, S. mitis, S. sanguinis, Lactobacillus acidophilus, P. gingivalis, Aggregatibacter actinomycetemcomitans, and Candida species were included in the study. Initially, agar diffusion assay was performed to screen the antimicrobial activities of Prunus mume extract. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were then determined for sensitive species. Effect of Prunus mume extract on human oral keratinocytes (HOK) viability was also tested. In the agar diffusion assay, drug suspension of 2 g/mL was able to inhibit all the bacterial species tested, but not the fungal species. MIC and MBC range of Prunus mume extract against the oral bacteria was 0.15625-0.0003 g/mL and P. gingivalis being the most susceptible species. Prune extract did not cause any detrimental effect on HOK. Prunus mume extract may be a potential candidate for developing an oral antimicrobial agent to control or prevent dental diseases associated with oral pathogenic bacteria. © 2011 The Authors. International Journal of Paediatric Dentistry © 2011 BSPD, IAPD and Blackwell Publishing Ltd.

Description of Diutina gen. nov., Diutina siamensis, f.a. sp. nov., and reassignment of Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida ranongensis, Candida rugosa and Candida scorzettiae to the genus Diutina.

PubMed

Khunnamwong, Pannida; Lertwattanasakul, Noppon; Jindamorakot, Sasitorn; Limtong, Savitree; Lachance, Marc-André

2015-12-01

Three strains (DMKU-RE28, DMKU-RE43T and DMKU-RE123) of a novel anamorphic yeast species were isolated from rice leaf tissue collected in Thailand. DNA sequence analysis demonstrated that the species forms a sister pair with Candida ranongensis CBS 10861T but differs by 24-30 substitutions in the LSU rRNA gene D1/D2 domains and 30-35 substitutions in the ITS region. A phylogenetic analysis based on both the small and the large rRNA gene subunits confirmed this connection and demonstrated the presence of a clade that also includes Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida rugosa and Candida scorzettiae. The clade is not closely affiliated to any known teleomorphic genus, and forms a well-separated lineage from currently recognized genera of the Saccharomycetales. Hence, the genus Diutina gen. nov. is proposed to accommodate members of the clade, including Diutina siamensis f.a. sp. nov. and the preceding seven Candida species. The type strain is DMKU-RE43T ( = CBS 13388T = BCC 61183T = NBRC 109695T).

Adhesins in Human Fungal Pathogens: Glue with Plenty of Stick

PubMed Central

de Groot, Piet W. J.; Bader, Oliver; de Boer, Albert D.; Weig, Michael

2013-01-01

Understanding the pathogenesis of an infectious disease is critical for developing new methods to prevent infection and diagnose or cure disease. Adherence of microorganisms to host tissue is a prerequisite for tissue invasion and infection. Fungal cell wall adhesins involved in adherence to host tissue or abiotic medical devices are critical for colonization leading to invasion and damage of host tissue. Here, with a main focus on pathogenic Candida species, we summarize recent progress made in the field of adhesins in human fungal pathogens and underscore the importance of these proteins in establishment of fungal diseases. PMID:23397570

Comparative effect of propolis of honey bee and some herbal extracts on Candida albicans.

PubMed

Gavanji, Shahin; Larki, Behrouz

2017-03-01

To determine the effect of propolis on Candida albicans and to compare it with the effects of some other herbal extracts and antibiotics on this pathogenic fungi. The extracts of propolis, Thymus vulgaris, Caryophillium aromaticus, Echinophora platyloba, Allium cepa and Cinnamomum zeylanicum were prepared and the antifungi effects of the extracts were examined on Candida albicans ATCC10231 using disc-diffusion assay and micro-broth dilution. The minimum fungicidal concentration (MFC) and minimum inhibitory concentrations (MIC) as well as inhibition zone were evaluated and the anti fungi effects of herbal extracts were compared with amphotricin B and nystatin at the times of 24, 48 and 72 h. Data analysis was performed using t test. Obtained results showed that propolis extract with MIC 90 and MFC equal to 39 and 65 μg/mL, respectively, possess the highest antifungal activity when compared with other studied extracts. The extracts of Allium cepa and Thymus vulgaris, with MFC of 169 and 137 μg/mL, respectively, showed the lowest effects on the fungi. Also nystatin and amphotricin B yielded better effects on the tested fungi compared with the effects of all studied extracts on Candida albicans. Propolis extract is effective in controlling Candida albicans. However, the issue requires further investigation on samples in animals and performing toxicological examinations.

Oropharyngeal candidiasis in children with lymphohematopoietic malignancies in Mashhad, Iran

PubMed Central

Berenji, F; Zabolinejad, N; Badiei, Z; Kakhi, S; Andalib Aliabadi, Z; Ganjbakhsh, M

2015-01-01

Background and Purpose: Over the past years, the role of fungi as a cause of nosocomial infections in hospitalized patients has been accentuated. Candida species constitute an important group of fungi causing diseases in immunocompromised patients. Oropharyngeal candidiasis continues to be a prevalent infection in immunodeficient patients. In this study, we aimed to determine the incidence of oropharyngeal candidiasis in children with lymphohematopoietic malignancies. Materials and Methods: In total, 102 patients with lymphohematopoietic malignancies and 50 healthy controls were examined in terms of Candida infections via direct sampling of the oropharyngeal cavity. Fresh smears were prepared with 10% potassium hydroxide and Gram staining was carried out. Subsequently, the obtained specimens were cultured on Sabouraud dextrose agar for further analysis. Results: The most common Candida species were Candida albicans (31%), other non-C. albicans species (14.7%), C. glabrata (6.8%), and C. krusei (0.98%) in the case group, while in the control group, other non-C. albicans species (10%) and C. albicans (8%) were the most common species. Conclusion: In the present study, Candida species were the most common fungal pathogens in pediatric cancer patients; therefore, efforts should be made to prevent fungemia and fungal pneumonia. Also, non-C. albicans species must be considered as a new risk factor for pediatric cancer patients. PMID:28681002

Oropharyngeal candidiasis in children with lymphohematopoietic malignancies in Mashhad, Iran.

PubMed

Berenji, F; Zabolinejad, N; Badiei, Z; Kakhi, S; Andalib Aliabadi, Z; Ganjbakhsh, M

2015-12-01

Over the past years, the role of fungi as a cause of nosocomial infections in hospitalized patients has been accentuated. Candida species constitute an important group of fungi causing diseases in immunocompromised patients. Oropharyngeal candidiasis continues to be a prevalent infection in immunodeficient patients. In this study, we aimed to determine the incidence of oropharyngeal candidiasis in children with lymphohematopoietic malignancies. In total, 102 patients with lymphohematopoietic malignancies and 50 healthy controls were examined in terms of Candida infections via direct sampling of the oropharyngeal cavity. Fresh smears were prepared with 10% potassium hydroxide and Gram staining was carried out. Subsequently, the obtained specimens were cultured on Sabouraud dextrose agar for further analysis. The most common Candida species were Candida albicans (31%), other non- C. albicans species (14.7%), C. glabrata (6.8%), and C. krusei (0.98%) in the case group, while in the control group, other non- C. albicans species (10%) and C. albicans (8%) were the most common species. In the present study, Candida species were the most common fungal pathogens in pediatric cancer patients; therefore, efforts should be made to prevent fungemia and fungal pneumonia. Also, non -C. albicans species must be considered as a new risk factor for pediatric cancer patients.

Candida albicans Chitin Increases Arginase-1 Activity in Human Macrophages, with an Impact on Macrophage Antimicrobial Functions

PubMed Central

MacCallum, Donna M.; Brown, Gordon D.

2017-01-01

ABSTRACT   The opportunistic human fungal pathogen Candida albicans can cause a variety of diseases, ranging from superficial mucosal infections to life-threatening systemic infections. Phagocytic cells of the innate immune response, such as neutrophils and macrophages, are important first-line responders to an infection and generate reactive oxygen and nitrogen species as part of their protective antimicrobial response. During an infection, host cells generate nitric oxide through the enzyme inducible nitric oxide synthase (iNOS) to kill the invading pathogen. Inside the phagocyte, iNOS competes with the enzyme arginase-1 for a common substrate, the amino acid l-arginine. Several pathogenic species, including bacteria and parasitic protozoans, actively modulate the production of nitric oxide by inducing their own arginases or the host’s arginase activity to prevent the conversion of l-arginine to nitric oxide. We report here that C. albicans blocks nitric oxide production in human-monocyte-derived macrophages by induction of host arginase activity. We further determined that purified chitin (a fungal cell wall polysaccharide) and increased chitin exposure at the fungal cell wall surface induces this host arginase activity. Blocking the C. albicans-induced arginase activity with the arginase-specific substrate inhibitor Nω-hydroxy-nor-arginine (nor-NOHA) or the chitinase inhibitor bisdionin F restored nitric oxide production and increased the efficiency of fungal killing. Moreover, we determined that C. albicans influences macrophage polarization from a classically activated phenotype toward an alternatively activated phenotype, thereby reducing antimicrobial functions and mediating fungal survival. Therefore, C. albicans modulates l-arginine metabolism in macrophages during an infection, potentiating its own survival. PMID:28119468

Evaluation of pathogenicity of Candida albicans in germination-ready states using a silkworm infection model.

PubMed

Matsumoto, Haruhito; Nagao, Jun-ichi; Cho, Tamaki; Kodama, Jun

2013-01-01

We previously developed an N-acetyl-D-glucosamine (GlcNAc) medium which induces Candida albicans to undergo a yeast-to-hyphal transition through a cAMP-PKA pathway. Microarray analysis demonstrated that 18 genes, including ALS3 that encodes a cell wall adhesion, were upregulated by 30-min incubation of yeast cells at 37°C in the GlcNAc medium. To investigate the differences between morphological transition and morphotype in C. albicans as a consequence of infection, this study utilized a silkworm infection model as an invertebrate mini-host. We prepared 3 different conditions of C. albicans cells in vitro by changing the incubation times in the GlcNAc medium: yeast-form cells at 0 min (Y0 cells), yeast-form cells in germination-ready state at 60 min (Y60 cells), and hyphal cells at 120 min (H120 cells), and compared their pathogenicities. We performed the infection study at various temperatures to find temperature-dependent virulence factors in vivo. Y60 cells in germination-ready state in the GlcNAc medium showed higher pathogenicity in vivo compared to Y0 and H120 cells at 30°C. Y60 cells proliferated in silkworms 24 h post-injection at 30°C, whereas the other 2 cell types did not. In vitro analysis demonstrated that Y60 cells, but not Y0 cells, germinated in the silkworm hemolymph at 30°C. However, Y0 and Y60 cells showed a similar degree of germination in the silkworm hemolymph at 37°C, although no significant difference in silkworm survival after infection with each cell type was observed at 37°C. These results suggested that the germination-ready state induced by the GlcNAc medium contributed to virulence in the silkworm.

Local, systemic, demographic, and health-related factors influencing pathogenic yeast spectrum and antifungal drug administration frequency in oral candidiasis: a retrospective study.

PubMed

Hertel, Moritz; Schmidt-Westhausen, Andrea Maria; Strietzel, Frank-Peter

2016-09-01

In order to identify oral candidiasis patients being at risk of carrying potentially drug-resistant Candida, the aim of the study was to detect local, systemic, demographic, and health-related factors influencing (I) yeast spectrum composition and (II) antifungal administration frequency. Additionally, the aim was to investigate (III) species shift occurrence. Data from 798 patients (496 females, 302 males; mean age 59.7) with oral candidiasis diagnosed based on positive clinical and microbial findings (species identification and CFU count) between 2006 and 2011 were retrospectively analyzed using Pearson's chi(2) test and regression analysis. Among 958 isolates, Candida albicans was the most frequently detected (76.8 %). Also, species intrinsically resistant to azoles were frequently isolated (15.8 and 17.7 % of isolates and patients). (I) Infections only caused by C. albicans were significantly associated with the use of inhalation steroids (p = 0.001) and antibiotics (p = 0.04), super-infection of lichen planus (p = 0.002), and the absence of removable dentures (p < 0.001). (II) Anti-mycotics were significantly more frequently administered in patients using inhalation steroids (p = 0.001), suffering from asthma/COPD, or smoking heavily (p = 0.003) and if C. albicans and non-albicans species were detected together (p = 0.001). (III) Pathogen composition did not change over time within the examined period (p = 0.239). Different variables enhance the presence of certain Candida and the antifungal prescription frequency. No species shift was evident. The major pathogen in oral candidiasis remains C. albicans. Nevertheless, therapeutic problems may be caused by the frequent presence of species intrinsically resistant to azoles, especially in patients wearing dentures.

Sequence variations and protein expression levels of the two immune evasion proteins Gpm1 and Pra1 influence virulence of clinical Candida albicans isolates.

PubMed

Luo, Shanshan; Hipler, Uta-Christina; Münzberg, Christin; Skerka, Christine; Zipfel, Peter F

2015-01-01

Candida albicans, the important human fungal pathogen uses multiple evasion strategies to control, modulate and inhibit host complement and innate immune attack. Clinical C. albicans strains vary in pathogenicity and in serum resistance, in this work we analyzed sequence polymorphisms and variations in the expression levels of two central fungal complement evasion proteins, Gpm1 (phosphoglycerate mutase 1) and Pra1 (pH-regulated antigen 1) in thirteen clinical C. albicans isolates. Four nucleotide (nt) exchanges, all representing synonymous exchanges, were identified within the 747-nt long GPM1 gene. For the 900-nt long PRA1 gene, sixteen nucleotide exchanges were identified, which represented synonymous, as well as non-synonymous exchanges. All thirteen clinical isolates had a homozygous exchange (A to G) at position 73 of the PRA1 gene. Surface levels of Gpm1 varied by 8.2, and Pra1 levels by 3.3 fold in thirteen tested isolates and these differences influenced fungal immune fitness. The high Gpm1/Pra1 expressing candida strains bound the three human immune regulators more efficiently, than the low expression strains. The difference was 44% for Factor H binding, 51% for C4BP binding and 23% for plasminogen binding. This higher Gpm1/Pra1 expressing strains result in enhanced survival upon challenge with complement active, Factor H depleted human serum (difference 40%). In addition adhesion to and infection of human endothelial cells was increased (difference 60%), and C3b surface deposition was less effective (difference 27%). Thus, variable expression levels of central immune evasion protein influences immune fitness of the human fungal pathogen C. albicans and thus contribute to fungal virulence.

First Nine Cases of Candida auris Infection Reported in Central America: Importance of Acurate Diagnosis and Susceptibility Testing

PubMed Central

Rodriguez, Ana Belen Arauz; Caceres, Diego H; Santiago, Erika; Armstrong, Paige; French, Amalia Rodriguez; Arosemena, Susan; Ramos, Carolina; Espinosa-Bode, Andres; Borace, Jovanna; Hayer, Lizbeth; Cedeño, Israel; Sosa, Nestor; Berkow, Elizabeth L; Lockhart, Shawn R; Jackson, Brendan R; Chiller, Tom

2017-01-01

Abstract Background Candida auris is an emerging multidrug-resistant pathogen associated with invasive infections and high mortality. This report describes the first 9 cases of C. auris in Central America in a hospital in Panama City, Panama, and highlights the challenges of accurate identification and methods for susceptibility testing. Methods Isolates initially identified at a Panama City acute care hospital during July–October 2016 as Candida haemulonii (a common misidentification for C. auris) or Candida species by Vitek® 2 automated system (bioMérieux) were further characterized by molecular methods. Antifungal susceptibility testing was performed and results were compared between standard and reference methodologies. Patient demographic, clinical, and laboratory data were collected from the medical record. Results A total of 14 isolates from 9 hospitalized patients were confirmed as C. auris. Isolates were from urine (11), blood (1), catheter tip (1) and pleural fluid (1). Results of susceptibility testing were highly discrepant between automated and reference techniques for fluconazole (92% resistant vs. 77%, respectively) and amphotericin B (100% vs. 8%). Six (67%) patients were male, and the mean age was 53 years (range 42–78). All patients were admitted to the intensive care unit and were mechanically ventilated. Seven (78%) patients died. Conclusion C. auris is present in Central America. Healthcare facilities in the region should be vigilant for this concerning pathogen, particularly given challenges in its identification and need for infection control precautions. Although automated testing overestimated amphotericin B resistance, most initial isolates were susceptible by reference testing. Disclosures All authors: No reported disclosures.

Combination of caspofungin or anidulafungin with antimicrobial peptides results in potent synergistic killing of Candida albicans and Candida glabrata in vitro.

PubMed

Harris, Mark R; Coote, Peter J

2010-04-01

Administering synergistic combinations of antifungals could be a route to overcome problems with toxicity and the development of resistance. Combination of the echinocandins caspofungin or anidulafungin with a range of structurally diverse antimicrobial peptides resulted in potent synergistic killing of Candida spp. in vitro. Fungicidal synergy was measured by calculating fractional inhibitory concentration indices from checkerboard assays as well as loss of viability. Inhibitory combinations of the antifungals did not induce cytotoxicity in vitro. However, in a murine model of systemic candidiasis, co-administration of caspofungin with one example of the cationic peptides tested, ranalexin, did not show enhanced efficacy compared with the single treatments alone. Further study using alternative peptides will identify whether this combination approach could represent a novel treatment for fungal pathogens. (c) 2009 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Prevalence of pathogenic yeasts and humoral antibodies to candida in diabetic patients.

PubMed Central

Odds, F C; Evans, E G; Taylor, M A; Wales, J K

1978-01-01

The prevalence of oral yeasts and humoral precipitating antibodies to candida was estimated in 204 unselected diabetic patients (172 outpatients and 32 inpatients). Yeasts, mainly Candida albicans, were isolated from the mouths of 41% of the outpatients and precipitins were found in 17.5% although none of the patients had clinically overt candidiasis. The extent of oral yeast colonisation and incidence of antibodies was not related to their antidiabetic treatment or to the duration of their diabetes. It was, however, related to the blood glucose and urine sugar levels at the time they were sampled, the highest incidence being among the diabetic inpatients with high blood glucose levels at the time of sampling and the lowest among outpatients with normal blood glucose levels at the time of sampling. There was no such correlation when diabetic control over the previous 12-month period was considered. PMID:711913

Ultra-fast low concentration detection of Candida pathogens utilizing high resolution micropore chips.

PubMed

Mulero, Rafael; Lee, Dong Heun; Kutzler, Michele A; Jacobson, Jeffrey M; Kim, Min Jun

2009-01-01

Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the pore, measurements are taken of changes in the current corresponding to the shape of individual yeasts as they translocate or travel through the pore. The direct ultra-fast low concentration electrical addressing of C. albicans has established criteria for distinguishing individual yeast based on their structural properties, which may reduce the currently used methods' complexity for both identification and quantification capabilities in mixed blood samples.

Ultra-Fast Low Concentration Detection of Candida Pathogens Utilizing High Resolution Micropore Chips

PubMed Central

Mulero, Rafael; Lee, Dong Heun; Kutzler, Michele A.; Jacobson, Jeffrey M.; Kim, Min Jun

2009-01-01

Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the pore, measurements are taken of changes in the current corresponding to the shape of individual yeasts as they translocate or travel through the pore. The direct ultra-fast low concentration electrical addressing of C. albicans has established criteria for distinguishing individual yeast based on their structural properties, which may reduce the currently used methods’ complexity for both identification and quantification capabilities in mixed blood samples. PMID:22573974

Antifungal agents commonly used in the superficial and mucosal candidiasis treatment: mode of action and resistance development

PubMed Central

Bondaryk, Małgorzata; Kurzątkowski, Wiesław

2013-01-01

Recent progress in medical sciences and therapy resulted in an increased number of immunocompromised individuals. Candida albicans is the leading opportunistic fungal pathogen causing infections in humans, ranging from superficial mucosal lesions to disseminated or bloodstream candidiasis. Superficial candidiasis not always presents a risk to the life of the infected host, however it significantly lowers the quality of life. Superficial Candida infections are difficult to treat and their frequency of occurrence is currently rising. To implement successful treatment doctors should be up to date with better understanding of C. albicans resistance mechanisms. Despite high frequency of Candida infections there is a limited number of antimycotics available for therapy. This review focuses on current understanding of the mode of action and resistance mechanisms to conventional and emerging antifungal agents for treatment of superficial and mucosal candidiasis. PMID:24353489

Clinical, microbiological, and experimental animal studies of Candida lipolytica.

PubMed Central

Walsh, T J; Salkin, I F; Dixon, D M; Hurd, N J

1989-01-01

Candida lipolytica was recovered from six patients in three different clinical centers. The index isolate caused a persistent fungemia with catheter-associated Candida thrombophlebitis, the second isolate was from a polymicrobial sinusitis, and the remaining four isolates were involved in tissue colonization. These and 20 other isolates were consistent in their morphological and physiological characteristics. All formed true hyphae and blastoconidia on cornmeal-Tween 80 agar and all assimilated glucose, glycerol, and erythritol. In a murine model of disseminated candidiasis, the index isolate that caused clinical fungemia caused no mortality and produced only two lesions on a kidney, as determined at necropsy. The nine isolates selected for in vitro antifungal susceptibility studies had intermediate susceptibilities to amphotericin B but were susceptible to ketoconazole. We conclude that C. lipolytica is a weakly virulent pathogen which may require an intravascular foreign body to cause fungemia. Images PMID:2745702

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-07-01

To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)% and (4.90-99.70)% v/v, respectively. This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.

A CRISPR Cas9-based gene drive platform for genetic interaction analysis in Candida albicans

PubMed Central

Shapiro, Rebecca S.; Chavez, Alejandro; Porter, Caroline B. M.; Hamblin, Meagan; Kaas, Christian S.; DiCarlo, James E.; Zeng, Guisheng; Xu, Xiaoli; Revtovich, Alexey V.; Kirienko, Natalia V.; Wang, Yue; Church, George M.; Collins, James J.

2018-01-01

Candida albicans is the leading cause of fungal infections; yet, complex genetic interaction analysis remains cumbersome in this diploid pathogen. Here, we developed a CRISPR-Cas9-based ‘gene drive array’ (GDA) platform to facilitate efficient genetic analysis in C. albicans. In our system, a modified DNA donor molecule acts as a selfish genetic element, replaces the targeted site, and propagates to replace additional wild-type loci. Using mating-competent C. albicans haploids, each carrying a different gene drive disabling a gene of interest, we are able to create diploid strains that are homozygous double-deletion mutants. We generate double-gene deletion libraries to demonstrate this technology, targeting antifungal efflux and biofilm adhesion factors. We screen these libraries to identify virulence regulators and determine how genetic networks shift under diverse conditions. This platform transforms our ability to perform genetic interaction analysis in C. albicans and is readily extended to other fungal pathogens. PMID:29062088

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed Central

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-01-01

Objective To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Methods Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. Results The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7–23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09–93.48)% and (4.90–99.70)% v/v, respectively. Conclusions This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans. PMID:23569970

Study of the prevalence and association of ocular chlamydial conjunctivitis in women with genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans attending outpatient clinic.

PubMed

Khattab, Rania Abdelmonem; Abdelfattah, Maha Mohssen

2016-01-01

To determine the association between chlamydial conjunctivitis and genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans, in addition to the possible relationship between cultured bacterial pathogens and oculogenital chlamydial infection. This study was performed on 100 (50 symptomatic and 50 asymptomatic) women attending the Gynecological and Obstetric outpatient clinic of Alzahra hospital, Alazhar University. Simultaneously a conjunctival swab was taken from these patients. Polymerase chain reaction (PCR) was done on DNA extracted from both vaginal and conjunctival swab samples. Culture for both vaginal and conjunctival swabs was also done. Candida albicans was the predominant organism isolated by culture in 20% and 40% of conjunctival and vaginal swabs respectively. By the PCR method, ocular Chlamydia trachomatis was present in 60% of symptomatic women, while genital Chlamydia trachomatis infection was present in 30% of symptomatic women. The results of this method also indicated that 25/50 (50%) vaginal swabs were positive with PCR for Candida albicans versus 15/50 (30%) were PCR positive in conjunctival swab. Mycoplasma genitalium was present in only 10% of vaginal swabs. Concomitant oculogenital PCR positive results for Chlamydia trachomatis and Candida albicans were 30% and 28% respectively. Ocular Chlamydia trachomatis was associated with genital Chlamydia trachomatis in a high percentage of women followed by Candida albicans. Cultured bacterial organisms do not play a role in enhancement of Chlamydia trachomatis infection.

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 of VVC among investigated women was higher than the previous report from Khuzestan but C. albicans has yet remained the predominant agent of VVC in this area. Given to the EAI, the virulence of C. albicans in VVC can be mediated by phospholipase, esterase and proteinases. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Emerging fungal infections among children: A review on its clinical manifestations, diagnosis, and prevention

PubMed Central

Jain, Akansha; Jain, Shubham; Rawat, Swati

2010-01-01

The incidence of fungal infections is increasing at an alarming rate, presenting an enormous challenge to healthcare professionals. This increase is directly related to the growing population of immunocompromised individuals especially children resulting from changes in medical practice such as the use of intensive chemotherapy and immunosuppressive drugs. Although healthy children have strong natural immunity against fungal infections, then also fungal infection among children are increasing very fast. Virtually not all fungi are pathogenic and their infection is opportunistic. Fungi can occur in the form of yeast, mould, and dimorph. In children fungi can cause superficial infection, i.e., on skin, nails, and hair like oral thrush, candida diaper rash, tinea infections, etc., are various types of superficial fungal infections, subcutaneous fungal infection in tissues under the skin and lastly it causes systemic infection in deeper tissues. Most superficial and subcutaneous fungal infections are easily diagnosed and readily amenable to treatment. Opportunistic fungal infections are those that cause diseases exclusively in immunocompromised individuals, e.g., aspergillosis, zygomycosis, etc. Systemic infections can be life-threatening and are associated with high morbidity and mortality. Because diagnosis is difficult and the causative agent is often confirmed only at autopsy, the exact incidence of systemic infections is difficult to determine. The most frequently encountered pathogens are Candida albicans and Aspergillus spp. But other fungi such as non-albicans Candida spp. are increasingly important. PMID:21180463

Adherence of Candida sp. to host tissues and cells as one of its pathogenicity features.

PubMed

Modrzewska, Barbara; Kurnatowski, Piotr

2015-01-01

The ability of Candida sp. cells to adhere to the mucosal surfaces of various host organs as well as synthetic materials is an important pathogenicity feature of those fungi which contributes to the development of infection. This property varies depending on the species of the fungus and is the greatest for C. albicans. The process of adhesion depends on plenty of factors related to the fungal and host cells as well as environmental conditions. The main adhesins present on the fungal cell wall are: Als, Epa, Hwp1, but also Eap1, Sun41, Csh1 and probably Hyr1; for adhesion significant are also secreted aspartyl proteases Sap. Various researchers specify a range of genes which contribute to adhesion, such as: CZF1, EFG1, TUP1, TPK1, TPK2, HGC1, RAS1, RIM101, VPS11, ECM1, CKA2, BCR1, BUD2, RSR1, IRS4, CHS2, SCS7, UBI4, UME6, TEC1 and GAT2. Influence for adherence have also heat shock proteins Hsp70, Mediator Middle domain subunit Med31 and morphological transition. Among factors affecting adhesion related to host cells it is necessary to mention fibronectins and integrins (receptors for Candida sp. adhesins), type of epithelial cells, their morphology and differentiation phase. To a lesser degree influence on adhesion have non-specific factors and environmental conditions.

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.

[Statement of the Polish Gynecological Society Expert Group on the use of Macmiror Complex 500].

PubMed

2012-12-01

The group of experts representing the Polish Gynecologic Society has issued this statement based on the review of available literature on the potential benefits of the use of Macmiror Complex 500 in obstetrical and gynecologic practice. Mixed Vaginitis (MV) eg. the vaginal infection caused by at least two out of the triad of pathogens (fungi, bacteria and Trichomonas Vaginalis [TV]), constitutes the type of vaginitis which is underestimated as for its prevalence. Mixed pathogens are responsible for as much as one third of all vaginal infections. Macmiror Complex 500 contains two active ingredients: nifuratel and nystatin. Macmiror Complex 500 affects all common causes of vulvovaginitis, i.e. bacteria, yeasts and TV. At the same time, it is not effective against Lactobacillus spp., which is a clear advantage in the treatment of vaginal infections. The antibacterial spectrum of nifuratel includes aerobic and anaerobic bacteria. Moreover nifuratel is effective against Chlamydia trachomatis and Mycoplasma spp., it has an anti-trichomonal effect comparable to metranidazole and shows certain activity against Candida spp. Nystatin is effective against Candida albicans and is even very effective against Candida glabrata which is usually more resistant to imidazole antifungal agents. Nystatin's importance is rising due to the current increase of candidoses caused by non-albicans types. This increase is especially perceptible in recurring candidoses. The review of the available literature on the effectiveness of Macmiror Complex 500 in the OB/GYN practice leads to the following conclusions: the exeptionally broad antibacterial and antifungal and trichomonicidal activity of this formulation makes it a drug of choice in cases where MV is suspected. The possibility to treat both partners, favorable safety profile in pregnant patients and the availability of both vaginal ovules and the cream with applicator makes this drug an effective and suitable treatment option in obstetrical and gynecologic practice.

In Vitro Antifungal Activity of KP-103, a Novel Triazole Derivative, and Its Therapeutic Efficacy against Experimental Plantar Tinea Pedis and Cutaneous Candidiasis in Guinea Pigs

PubMed Central

Tatsumi, Yoshiyuki; Yokoo, Mamoru; Arika, Tadashi; Yamaguchi, Hideyo

2001-01-01

The in vitro activity of KP-103, a novel triazole derivative, against pathogenic fungi that cause dermatomycoses and its therapeutic efficacy against plantar tinea pedis and cutaneous candidiasis in guinea pigs were investigated. MICs were determined by a broth microdilution method with morpholinepropanesulfonic acid-buffered RPMI 1640 medium for Candida species and with Sabouraud dextrose broth for dermatophytes and by an agar dilution method with medium C for Malassezia furfur. KP-103 was the most active of all the drugs tested against Candida albicans (geometric mean [GM] MIC, 0.002 μg/ml), other Candida species including Candida parapsilosis and Candida glabrata (GM MICs, 0.0039 to 0.0442 μg/ml), and M. furfur (GM MIC, 0.025 μg/ml). KP-103 (1% solution) was highly effective as a treatment for guinea pigs with cutaneous candidiasis and achieved mycological eradication in 8 of the 10 infected animals, whereas none of the imidazoles tested (1% solutions) was effective in even reducing the levels of the infecting fungi. KP-103 was as active as clotrimazole and neticonazole but was less active than lanoconazole and butenafine against Trichophyton rubrum (MIC at which 80% of isolates are inhibited [MIC80], 0.125 μg/ml) and Trichophyton mentagrophytes (MIC80, 0.25 μg/ml). However, KP-103 (1% solution) exerted therapeutic efficacy superior to that of neticonazole and comparable to those of lanoconazole and butenafine, yielding negative cultures for all samples from guinea pigs with plantar tinea pedis tested. This suggests that KP-103 has better pharmacokinetic properties in skin tissue than the reference drugs. Because the in vitro activity of KP-103, unlike those of the reference drugs, against T. mentagrophytes was not affected by hair as a keratinic substance, its excellent therapeutic efficacy seems to be attributable to good retention of its antifungal activity in skin tissue, in addition to its potency. PMID:11302816

Investigation of the First Seven Reported Cases of Candida auris, a Globally Emerging Invasive, Multidrug-Resistant Fungus - United States, May 2013-August 2016.

PubMed

Vallabhaneni, Snigdha; Kallen, Alex; Tsay, Sharon; Chow, Nancy; Welsh, Rory; Kerins, Janna; Kemble, Sarah K; Pacilli, Massimo; Black, Stephanie R; Landon, Emily; Ridgway, Jessica; Palmore, Tara N; Zelzany, Adrian; Adams, Eleanor H; Quinn, Monica; Chaturvedi, Sudha; Greenko, Jane; Fernandez, Rafael; Southwick, Karen; Furuya, E Yoko; Calfee, David P; Hamula, Camille; Patel, Gopi; Barrett, Patricia; Lafaro, Patricia; Berkow, Elizabeth L; Moulton-Meissner, Heather; Noble-Wang, Judith; Fagan, Ryan P; Jackson, Brendan R; Lockhart, Shawn R; Litvintseva, Anastasia P; Chiller, Tom M

2016-11-11

Candida auris, an emerging fungus that can cause invasive infections, is associated with high mortality and is often resistant to multiple antifungal drugs. C. auris was first described in 2009 after being isolated from external ear canal discharge of a patient in Japan (1). Since then, reports of C. auris infections, including bloodstream infections, have been published from several countries, including Colombia, India, Israel, Kenya, Kuwait, Pakistan, South Africa, South Korea, Venezuela, and the United Kingdom (2-7). To determine whether C. auris is present in the United States and to prepare for the possibility of transmission, CDC issued a clinical alert in June 2016 informing clinicians, laboratorians, infection control practitioners, and public health authorities about C. auris and requesting that C. auris cases be reported to state and local health departments and CDC (8). This report describes the first seven U.S. cases of C. auris infection reported to CDC as of August 31, 2016. Data from these cases suggest that transmission of C. auris might have occurred in U.S. health care facilities and demonstrate the need for attention to infection control measures to control the spread of this pathogen.

Membership and Behavior of Ultra-Low-Diversity Pathogen Communities Present in the Gut of Humans during Prolonged Critical Illness

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

Zaborin, Alexander; Smith, Daniel; Garfield, Kevin

We analyzed the 16S rRNA amplicon composition in fecal samples of selected patients during their prolonged stay in an intensive care unit (ICU) and observed the emergence of ultra-low-diversity communities (1 to 4 bacterial taxa) in 30% of the patients. Bacteria associated with the genera Enterococcus and Staphylococcus and the family Enterobacteriaceae comprised the majority of these communities. The composition of cultured species from stool samples correlated to the 16S rRNA analysis and additionally revealed the emergence of Candida albicans and Candida glabrata in ~75% of cases. Four of 14 ICU patients harbored 2-member pathogen communities consisting of one Candidamore » taxon and one bacterial taxon. Bacterial members displayed a high degree of resistance to multiple antibiotics. The virulence potential of the 2-member communities was examined in C. elegans during nutrient deprivation and exposure to opioids in order to mimic local conditions in the gut during critical illness. Under conditions of nutrient deprivation, the bacterial members attenuated the virulence of fungal members, leading to a “commensal lifestyle.” However, exposure to opioids led to a breakdown in this commensalism in 2 of the ultra-low-diversity communities. Application of a novel antivirulence agent (phosphate-polyethylene glycol [Pi-PEG]) that creates local phosphate abundance prevented opioid-induced virulence among these pathogen communities, thus rescuing the commensal lifestyle. To conclude, the gut microflora in critically ill patients can consist of ultra-low-diversity communities of multidrug-resistant pathogenic microbes. Local environmental conditions in gut may direct pathogen communities to adapt to either a commensal style or a pathogenic style.« less

Membership and Behavior of Ultra-Low-Diversity Pathogen Communities Present in the Gut of Humans during Prolonged Critical Illness

DOE PAGES

Zaborin, Alexander; Smith, Daniel; Garfield, Kevin; ...

2014-09-23

We analyzed the 16S rRNA amplicon composition in fecal samples of selected patients during their prolonged stay in an intensive care unit (ICU) and observed the emergence of ultra-low-diversity communities (1 to 4 bacterial taxa) in 30% of the patients. Bacteria associated with the genera Enterococcus and Staphylococcus and the family Enterobacteriaceae comprised the majority of these communities. The composition of cultured species from stool samples correlated to the 16S rRNA analysis and additionally revealed the emergence of Candida albicans and Candida glabrata in ~75% of cases. Four of 14 ICU patients harbored 2-member pathogen communities consisting of one Candidamore » taxon and one bacterial taxon. Bacterial members displayed a high degree of resistance to multiple antibiotics. The virulence potential of the 2-member communities was examined in C. elegans during nutrient deprivation and exposure to opioids in order to mimic local conditions in the gut during critical illness. Under conditions of nutrient deprivation, the bacterial members attenuated the virulence of fungal members, leading to a “commensal lifestyle.” However, exposure to opioids led to a breakdown in this commensalism in 2 of the ultra-low-diversity communities. Application of a novel antivirulence agent (phosphate-polyethylene glycol [Pi-PEG]) that creates local phosphate abundance prevented opioid-induced virulence among these pathogen communities, thus rescuing the commensal lifestyle. To conclude, the gut microflora in critically ill patients can consist of ultra-low-diversity communities of multidrug-resistant pathogenic microbes. Local environmental conditions in gut may direct pathogen communities to adapt to either a commensal style or a pathogenic style.« less

Antifungal isopimaranes from Hypoestes serpens.

PubMed

Rasoamiaranjanahary, L; Guilet, D; Marston, A; Randimbivololona, F; Hostettmann, K

2003-09-01

Five isopimarane diterpenes (7beta-hydroxyisopimara-8,15-dien-14-one, 14alpha-hydroxyisopimara-7,15-dien-1-one, 1beta,14alpha-dihydroxyisopimara-7,15-diene, 7beta-hydroxyisopimara-8(14),15-dien-1-one and 7beta-acetoxyisopimara-8(14),15-dien-1-one) have been isolated from the leaves of Hypoestes serpens (Acanthaceae). All compounds exhibited antifungal activity against both the plant pathogenic fungus Cladosporium cucumerinum and the yeast Candida albicans; two of them also displayed an acetylcholinesterase inhibition. The structures of the compounds were determined by means of spectrometric methods, including 1D and 2D NMR experiments and MS analysis.

Fluconazole resistance in Candida species: a current perspective

PubMed Central

Berkow, Elizabeth L; Lockhart, Shawn R

2017-01-01

Candida albicans and the emerging non-albicans Candida spp. have significant clinical relevance among many patient populations. Current treatment guidelines include fluconazole as a primary therapeutic option for the treatment of these infections, but it is only fungistatic against Candida spp. and both inherent and acquired resistance to fluconazole have been reported. Such mechanisms of resistance include increased drug efflux, alteration or increase in the drug target, and development of compensatory pathways for producing the target sterol, ergosterol. While many mechanisms of resistance observed in C. albicans are also found in the non-albicans species, there are also important and unexpected differences between species. Furthermore, mechanisms of fluconazole resistance in emerging Candida spp., including the global health threat Candida auris, are largely unknown. In order to preserve the utility of one of our fundamental antifungal drugs, fluconazole, it is essential that we fully appreciate the manner by which Candida spp. manifest resistance to it. PMID:28814889

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.

Development of a specific polymerase chain reaction assay for the detection of Basidiobolus.

PubMed

Gómez-Muñoz, María Teresa; Fernández-Barredo, Salceda; Martínez-Díaz, Rafael Alberto; Pérez-Gracia, María Teresa; Ponce-Gordo, Francisco

2012-01-01

The etiology of chronic diarrhea is complex in humans and animals. It is always necessary to evaluate a list of differential diagnosis, including bacteria, protozoa and fungi. Basidiobolomycosis is a fungal disease reported sporadically worldwide, mainly caused by B. ranarum, a frequent organism found in soil or in the intestine and skin of lizards and frogs. It is an opportunistic pathogen that causes infections characterized by granulomatous lesions in the subcutaneous tissues as well as in the intestinal wall in humans and animals. In this work we have developed a PCR technique to differentiate Basidiobolus from other causes of intestinal disease in dogs and humans. To test the specificity of the PCR assay we included closely related organisms, common intestinal microbiota and pathogenic organisms, such as Aspergillus, Candida, Cryptosporidium, Escherichia, Giardia, Mucor, Proteus, Rhizopus and Salmonella. Pythium insidiosum, which cause clinically similar disease in dogs but require a different treatment. Only Basidiobolus was positive to the PCR assay.

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 show that, in the host, even a successful human pathogen can rely largely on a strategy normally found in nonpathogenic fungi from a terrestrial environment. Copyright © 2016 Gerwien et al.

[The interaction of pathogenic microorganisms with the sorbent polymethylsiloxane].

PubMed

Dikova, I G; Il'chenko, O I; Ruban, V I; Samodumova, I M; Sidel'nikova, L F

1993-01-01

The method of electron microscopy has been used to study adhesion of the microbic cells of standard strains of Staphylococcus aureus, Escherichia coli and fungi of genus Candida on the organosilicon sorbent polymethylsiloxane (PMS) and medicamentous complex containing it. This complex contains furazolidone and metronidazole immobilized on silver ions-modified PMS. It is shown that the adhesion of microorganisms is accompanied by their destruction whose rate on pure PMS and medicamentous complex is different. Using experimental data the assumptions are advanced concerning the mechanism of the PMS interaction with Gram-positive and Gram-negative microorganisms as well as with fungi of genus Candida.

The Candida albicans Biofilm Matrix: Composition, Structure and Function.

PubMed

Pierce, Christopher G; Vila, Taissa; Romo, Jesus A; Montelongo-Jauregui, Daniel; Wall, Gina; Ramasubramanian, Anand; Lopez-Ribot, Jose L

2017-03-01

A majority of infections caused by Candida albicans -the most frequent fungal pathogen-are associated with biofilm formation. A salient feature of C. albicans biofilms is the presence of the biofilm matrix. This matrix is composed of exopolymeric materials secreted by sessile cells within the biofilm, in which all classes of macromolecules are represented, and provides protection against environmental challenges. In this review, we summarize the knowledge accumulated during the last two decades on the composition, structure, and function of the C. albicans biofilm matrix. Knowledge of the matrix components, its structure, and function will help pave the way to novel strategies to combat C. albicans biofilm infections.

Innocent until proven guilty: mechanisms and roles of Streptococcus–Candida interactions in oral health and disease

PubMed Central

Xu, H; Jenkinson, HF; Dongari-Bagtzoglou, A

2014-01-01

Summary Candida albicans and streptococci of the mitis group colonize the oral cavities of the majority of healthy humans. While C. albicans is considered an opportunistic pathogen, streptococci of this group are broadly considered avirulent or even beneficial organisms. However, recent evidence suggests that multi-species biofilms with these organisms may play detrimental roles in host homeostasis and may promote infection. In this review we summarize the literature on molecular interactions between members of this streptococcal group and C. albicans, with emphasis on their potential role in the pathogenesis of opportunistic oral mucosal infections. PMID:24877244

A potential plant-derived antifungal acetylenic acid mediates its activity by interfering with fatty acid homeostasis

USDA-ARS?s Scientific Manuscript database

6-Nonadecynoic acid (6-NDA), a plant-derived acetylenic acid, exhibits strong inhibitory activity against the human fungal pathogens Candida albicans, Aspergillus fumigatus, and Trichophyton mentagrophytes. In the present study, transcriptional profiling coupled with mutant and biochemical analyses...

Integrated inference and evaluation of host–fungi interaction networks

PubMed Central

Remmele, Christian W.; Luther, Christian H.; Balkenhol, Johannes; Dandekar, Thomas; Müller, Tobias; Dittrich, Marcus T.

2015-01-01

Fungal microorganisms frequently lead to life-threatening infections. Within this group of pathogens, the commensal Candida albicans and the filamentous fungus Aspergillus fumigatus are by far the most important causes of invasive mycoses in Europe. A key capability for host invasion and immune response evasion are specific molecular interactions between the fungal pathogen and its human host. Experimentally validated knowledge about these crucial interactions is rare in literature and even specialized host–pathogen databases mainly focus on bacterial and viral interactions whereas information on fungi is still sparse. To establish large-scale host–fungi interaction networks on a systems biology scale, we develop an extended inference approach based on protein orthology and data on gene functions. Using human and yeast intraspecies networks as template, we derive a large network of pathogen–host interactions (PHI). Rigorous filtering and refinement steps based on cellular localization and pathogenicity information of predicted interactors yield a primary scaffold of fungi–human and fungi–mouse interaction networks. Specific enrichment of known pathogenicity-relevant genes indicates the biological relevance of the predicted PHI. A detailed inspection of functionally relevant subnetworks reveals novel host–fungal interaction candidates such as the Candida virulence factor PLB1 and the anti-fungal host protein APP. Our results demonstrate the applicability of interolog-based prediction methods for host–fungi interactions and underline the importance of filtering and refinement steps to attain biologically more relevant interactions. This integrated network framework can serve as a basis for future analyses of high-throughput host–fungi transcriptome and proteome data. PMID:26300851

Specific Human and Candida Cellular Interactions Lead to Controlled or Persistent Infection Outcomes during Granuloma-Like Formation

PubMed Central

Misme-Aucouturier, Barbara; Albassier, Marjorie

2016-01-01

ABSTRACT A delayed type of multicellular process could be crucial during chronic candidiasis in determining the course of infection. This reaction, consisting of organized immune cells surrounding the pathogen, initiates an inflammatory response to avoid fungal dissemination. The goal of the present study was to examine, at an in vitro cellular scale, Candida and human immune cell interaction dynamics during a long-term period. By challenging human peripheral blood immune cells from 10 healthy donors with 32 Candida albicans and non-albicans (C. glabrata, C. tropicalis, C. parapsilosis, C. dubliniensis, C. lusitaniae, C. krusei, and C. kefyr) clinical isolates, we showed that Candida spp. induced the formation of granuloma-like structures within 6 days after challenge, but their sizes and the respective fungal burdens differed according to the Candida species. These two parameters are positively correlated. Phenotypic characteristics, such as hypha formation and higher axenic growth rate, seem to contribute to yeast persistence within granuloma-like structures. We showed an interindividual variability of the human response against Candida spp. Higher proportions of neutrophils and elevated CD4+/CD8+ T cell ratios during the first days after challenge were correlated with early production of gamma interferon (IFN-γ) and associated with controlled infection. In contrast, the persistence of Candida could result from upregulation of proinflammatory cytokines such as interleukin-6 (IL-6), IFN-γ, and tumor necrosis factor alpha (TNF-α) and a poor anti-inflammatory negative feedback (IL-10). Importantly, regulatory subsets of NK cells and CD4lo CD8hi doubly positive (DP) lymphocytes at late stage infiltrate granuloma-like structures and could correlate with the IL-10 and TNF-α production. These data offer a base frame to explain cellular events that guide infection control or fungal persistence. PMID:27799331

Comparative Study of Esterase and Hemolytic Activities in Clinically Important Candida Species, Isolated From Oral Cavity of Diabetic and Non-diabetic Individuals.

PubMed

Fatahinia, Mahnaz; Poormohamadi, Farzad; Zarei Mahmoudabadi, Ali

2015-03-01

Diabetes mellitus as a chronic metabolic disease occurs in patients with partial or complete deficiency of insulin secretion or disorder in action of insulin on tissue. The disease is known to provide conditions for overgrowth of Candida species. Candida spp. cause candidiasis by many virulence factors such as esterase, hemolysin and phospholipase. This study aimed to compare esterase and hemolytic activity in various Candida species isolated from oral cavity of diabetic and non-diabetic individuals. Swab samples were taken from 95 patients with diabetes (35 men and 60 women) and 95 normal persons (42 men and 53 women) and cultured on Sabouraud dextrose agar. Identification of isolated yeasts was performed by germ tube test, morphology on CHROMagar Candida medium, corn meal agar and ability to grow at 45°C. Hemolysin activity was evaluated using blood plate assay and esterase activity was determined using the Tween 80 opacity test. Different Candida species were isolated from 57 (60%) diabetic and 24 (25%) non-diabetic individuals. Esterase activity was detected in all Candida isolates. Only 21.6% of C. albicans from patients with diabetes had esterase activity as + 3, while it ranged from + 1 to + 2 in others. Hemolytic activity was determined in C. albicans, C. dubliniensis, C. glabrata and C. krusei as 0.79, 0.58, 0.66 and 0.74, respectively. Hemolytic activity was significantly different in the two groups of diabetics and non-diabetics. Oral carriage of C. albicans in the diabetic group (n = 42; 66.7%) was significantly greater than the control group (n = 16; 57.1%). Esterase activity of C. albicans in diabetic group was higher than non-diabetic group. Although C. albicans remains the most frequently pathogenic yeast for human, but other species are increasing.

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

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.

Evaluation of two matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems for the identification of Candida species.

PubMed

Lacroix, C; Gicquel, A; Sendid, B; Meyer, J; Accoceberry, I; François, N; Morio, F; Desoubeaux, G; Chandenier, J; Kauffmann-Lacroix, C; Hennequin, C; Guitard, J; Nassif, X; Bougnoux, M-E

2014-02-01

Candida spp. are responsible for severe infections in immunocompromised patients and those undergoing invasive procedures. The accurate identification of Candida species is important because emerging species can be associated with various antifungal susceptibility spectra. Conventional methods have been developed to identify the most common pathogens, but have often failed to identify uncommon species. Several studies have reported the efficiency of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of clinically relevant Candida species. In this study, we evaluated two commercially available MALDI-TOF systems, Andromas™ and Bruker Biotyper™, for Candida identification in routine diagnosis. For this purpose, we investigated 1383 Candida isolates prospectively collected in eight hospital laboratories during routine practice. MALDI-TOF MS results were compared with those obtained using conventional phenotypic methods. Analysis of rDNA gene sequences with internal transcribed regions or D1-D2 regions is considered the reference standard for identification. Both MALDI-TOF MS systems could accurately identify 98.3% of the isolates at the species level (1359/1383 for Andromas™; 1360/1383 for Bruker Biotyper™) vs. 96.5% for conventional techniques. Furthermore, whereas conventional methods failed to identify rare or emerging species, these were correctly identified by MALDI-TOF MS. Both MALDI-TOF MS systems are accurate and cost-effective alternatives to conventional methods for mycological identification of clinically relevant Candida species and should improve the diagnosis of fungal infections as well as patient management. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

Fungal Infections of the Spine.

PubMed

Ganesh, Devin; Gottlieb, Jonathan; Chan, Sherilynn; Martinez, Octavio; Eismont, Frank

2015-06-15

Review of the literature. To retrospectively examine the frequency of published fungal infections by species and the treatment algorithms used to eradicate the disease. Fungal infections of the spine present unique challenges to the modern multispecialty treatment team. Although rare in comparison with bacterial infections, fungal infections have been increasing in incidence over the past several decades. Evidences-based practice is limited to referencing smaller case series. MEDLINE, Scopus, and EMBASE searches were carried out by one of the authors as well as by the research desk at the University of Miami/Calder Memorial Library. We included peer-reviewed articles published between 1948 and September 2010; case reports, series, and reviews were all examined and compiled into a database. A total of 130 articles, representing 157 cases, were included in the review. Aspergillus (60 cases, 38.2% of the total) and Candida species (36 cases, 22.9% of the total) were the 2 most common organisms. Surgery was associated with a greater survival rate than medical management alone in patients with Aspergillus (26.9% mortality in surgical patients; 60% in medically treated patients) and Candida (0% vs. 28.6%). Overall mortality was 19.3%. The overall recurrence rate was 7.4%. Amphotericin use was associated with a higher mortality rate than azoles. Aspergillus is the most common published pathogen in fungal infections of the spine. Recent publications depicting the use of newer antifungal medications such as azoles report higher survival rates. Surgically treated patients in combination with antifungal therapy showed highest frequencies of patient survival in Aspergillus and Candida infections. 3.

Evaluation of MALDI-TOF-MS for the Identification of Yeast Isolates Causing Bloodstream Infection.

PubMed

Turhan, Ozge; Ozhak-Baysan, Betil; Zaragoza, Oscar; Er, Halil; Sarıtas, Zubeyde Eres; Ongut, Gozde; Ogunc, Dilara; Colak, Dilek; Cuenca-Estrella, Manuel

2017-04-01

Infections due to Candida species are major causes of morbidity and mortality in humans, causing a diverse spectrum of clinical disease ranging from superficial and mucosal infections to invasive disease. Several authors have demonstrated that mortality is closely linked to both timing of therapy and/or source control. The rapid identification of pathogenic species is helpful to start timely and effective antifungal therapy. The aim of this study was to assess the performance of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system for the correct and rapid identification of yeast isolates causing bloodstream infection. Between January 2014 and January 2015, a total of 117 yeast like organisms isolated from blood culture samples of 117 episodes from 102 patients who had blood stream infections were included in the study. The isolates were identified by MALDI-TOF MS. The results were compared with those obtained by the standard mycological methods and/or sequence analysis. One hundred and seventeen yeast isolates including 115 Candida spp and two non-Candida yeasts were analysed. The Biotyper correctly identified 115 (98.3%) isolates to the genus level and 102 (87.2%) isolates to the species level using the manufacturer's recommended cutoff scores. The Bruker Biotyper is a rapid, easy, inexpensive, and highly reliable system for the identification of yeast isolates. Early identification with MALDI-TOF MS would save time for determination of antifungal susceptibility and proper treatment strategy. The expansion of the database of the library by addition of less common species will improve the performance of the system.

Subtilomycin: A New Lantibiotic from Bacillus subtilis Strain MMA7 Isolated from the Marine Sponge Haliclona simulans

PubMed Central

Phelan, Robert W.; Barret, Matthieu; Cotter, Paul D.; O’Connor, Paula M.; Chen, Rui; Morrissey, John P.; Dobson, Alan D. W.; O’Gara, Fergal; Barbosa, Teresa M.

2013-01-01

Bacteriocins are attracting increased attention as an alternative to classic antibiotics in the fight against infectious disease and multidrug resistant pathogens. Bacillus subtilis strain MMA7 isolated from the marine sponge Haliclona simulans displays a broad spectrum antimicrobial activity, which includes Gram-positive and Gram-negative pathogens, as well as several pathogenic Candida species. This activity is in part associated with a newly identified lantibiotic, herein named as subtilomycin. The proposed biosynthetic cluster is composed of six genes, including protein-coding genes for LanB-like dehydratase and LanC-like cyclase modification enzymes, characteristic of the class I lantibiotics. The subtilomycin biosynthetic cluster in B. subtilis strain MMA7 is found in place of the sporulation killing factor (skf) operon, reported in many B. subtilis isolates and involved in a bacterial cannibalistic behaviour intended to delay sporulation. The presence of the subtilomycin biosynthetic cluster appears to be widespread amongst B. subtilis strains isolated from different shallow and deep water marine sponges. Subtilomycin possesses several desirable industrial and pharmaceutical physicochemical properties, including activity over a wide pH range, thermal resistance and water solubility. Additionally, the production of the lantibiotic subtilomycin could be a desirable property should B. subtilis strain MMA7 be employed as a probiotic in aquaculture applications. PMID:23736764

The Emerging Pathogen Candida auris: Growth Phenotype, Virulence Factors, Activity of Antifungals, and Effect of SCY-078, a Novel Glucan Synthesis Inhibitor, on Growth Morphology and Biofilm Formation.

PubMed

Larkin, Emily; Hager, Christopher; Chandra, Jyotsna; Mukherjee, Pranab K; Retuerto, Mauricio; Salem, Iman; Long, Lisa; Isham, Nancy; Kovanda, Laura; Borroto-Esoda, Katyna; Wring, Steve; Angulo, David; Ghannoum, Mahmoud

2017-05-01

Candida auris , a new multidrug-resistant Candida spp. which is associated with invasive infection and high rates of mortality, has recently emerged. Here, we determined the virulence factors (germination, adherence, biofilm formation, phospholipase and proteinase production) of 16 C. auris isolates and their susceptibilities to 11 drugs belonging to different antifungal classes, including a novel orally bioavailable 1,3-β-d-glucan synthesis inhibitor (SCY-078). We also examined the effect of SCY-078 on the growth, ultrastructure, and biofilm-forming abilities of C. auris Our data showed that while the tested strains did not germinate, they did produce phospholipase and proteinase in a strain-dependent manner and had a significantly reduced ability to adhere and form biofilms compared to that of Candida albicans ( P = 0.01). C. auris isolates demonstrated reduced susceptibility to fluconazole and amphotericin B, while, in general, they were susceptible to the remaining drugs tested. SCY-078 had an MIC 90 of 1 mg/liter against C. auris and caused complete inhibition of the growth of C. auris and C. albicans Scanning electron microscopy analysis showed that SCY-078 interrupted C. auris cell division, with the organism forming abnormal fused fungal cells. Additionally, SCY-078 possessed potent antibiofilm activity, wherein treated biofilms demonstrated significantly reduced metabolic activity and a significantly reduced thickness compared to the untreated control ( P < 0.05 for both comparisons). Our study shows that C. auris expresses several virulence determinants (albeit to a lesser extent than C. albicans ) and is resistant to fluconazole and amphotericin B. SCY-078, the new orally bioavailable antifungal, had potent antifungal/antibiofilm activity against C. auris , indicating that further evaluation of this antifungal is warranted. Copyright © 2017 Larkin et al.

Investigating the antifungal activity and mechanism(s) of geraniol against Candida albicans strains.

PubMed

Leite, Maria Clerya Alvino; de Brito Bezerra, André Parente; de Sousa, Janiere Pereira; de Oliveira Lima, Edeltrudes

2015-04-01

Candida albicans can be a yeast that is a commensal on the human body but can cause opportunistic or pathogenic infections. Candida infections may create serious health problems and as a result has initiated a search for new drugs with an antifungal action. Geraniol is an acyclic monoterpene alcohol with known pharmacological properties, including antimicrobial activity. The aim of this work was to evaluate the antifungal activity and mechanism(s) of geraniol against C. albicans strains. The minimum inhibitory concentration (MIC) was determined through broth microdilution techniques. We investigated possible geraniol activity on the fungal cell wall (sorbitol protect effect), cell membrane (geraniol to ergosterol binding), the time-kill curve, and its biological activity on the yeast's morphology. Amphotericin B was used as control, and all tests were performed in duplicate. The MIC of geraniol was 16 μg/ml (for 90% of isolates) but its probable mechanism of action did not involve the cell wall and ergosterol binding. In the morphological interference assay, we observed that the product inhibited pseudohyphae and chlamydoconidia formation. Time-dependent kill curve assay demonstrated that the fungicidal activity for MIC × 2 started at 2 h for the ATCC 76485 strain, and at 4 h for the LM-70 strain. Geraniol showed in vitro antifungal potential against strains of C. albicans but did not involve action on the cell wall or ergosterol. This study contributes to the development of new antifungal drugs, especially against Candida spp. © The Author 2014. 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.

Implicit dosimetry of microorganism photodynamic inactivation

NASA Astrophysics Data System (ADS)

Tamošiūnas, Mindaugas; Kuliešienė, Neringa; Daugelavičius, Rimantas

2017-12-01

Photosensitization based antibacterial treatment is efficient against a broad range of pathogens but it utilizes suboptimal dosimetry with an explicit (and very broad range) determination of sensitizer concentration, light dose and fluence rates. In this study we verified the implicit dosimetry approach for pathogen photodynamic treatment, employing protoporphyrin IX (ppIX) photobleaching to assess the killing efficacy against Staphylococcus aureus and Candida albicans cells. The results show that there was an increased kill of S. aureus and C. albicans at higher degree of ppIX fluorescence decay. Therefore ppIX photobleaching can be incorporated into the PDI dose metric offering to predict the pathogen killing efficacy during photodynamic treatment.

Iron and copper as virulence modulators in human fungal pathogens.

PubMed

Ding, Chen; Festa, Richard A; Sun, Tian-Shu; Wang, Zhan-You

2014-07-01

Fungal pathogens have evolved sophisticated machinery to precisely balance the fine line between acquiring essential metals and defending against metal toxicity. Iron and copper are essential metals for many processes in both fungal pathogens and their mammalian hosts, but reduce viability when present in excess. However, during infection, the host uses these two metals differently. Fe has a long-standing history of influencing virulence in pathogenic fungi, mostly in regards to Fe acquisition. Numerous studies demonstrate the requirement of the Fe acquisition pathway of Candida, Cryptococcus and Aspergillus for successful systemic infection. Fe is not free in the host, but is associated with Fe-binding proteins, leading fungi to develop mechanisms to interact with and to acquire Fe from these Fe-bound proteins. Cu is also essential for cell growth and development. Essential Cu-binding proteins include Fe transporters, superoxide dismutase (SOD) and cytochrome c oxidase. Although Cu acquisition plays critical roles in fungal survival in the host, recent work has revealed that Cu detoxification is extremely important. Here, we review fungal responses to altered metal conditions presented by the host, contrast the roles of Fe and Cu during infection, and outline the critical roles of fungal metal homeostasis machinery at the host-pathogen axis. © 2014 John Wiley & Sons Ltd.

Sexual reproduction and the evolution of microbial pathogens.

PubMed

Heitman, Joseph

2006-09-05

Three common systemic human fungal pathogens--Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus--have retained all the machinery to engage in sexual reproduction, and yet their populations are often clonal with limited evidence for recombination. Striking parallels have emerged with four protozoan parasites that infect humans: Toxoplasma gondii, Trypanosoma brucei, Trypanosoma cruzi and Plasmodium falciparum. Limiting sexual reproduction appears to be a common virulence strategy, enabling generation of clonal populations well adapted to host and environmental niches, yet retaining the ability to engage in sexual or parasexual reproduction and respond to selective pressure. Continued investigation of the sexual nature of microbial pathogens should facilitate both laboratory investigation and an understanding of the complex interplay between pathogens, hosts, vectors, and their environments.

Frequency of Candida albicans in Patients with Funguria.

PubMed

Jamil, Sana; Jamil, Naz; Saad, Uzma; Hafiz, Saleem; Siddiqui, Sualleha

2016-02-01

To determine the frequency of Candida albicansin patients with funguria. Descriptive cross-sectional study. Department of Microbiology, Sindh Institute of Urology and Transplantation, from July to December 2012. Patients’ urine samples with fungus/Candida were included. Candida albicans was identified by the production of tubular structures (germ tubes) on microscopy as per standard procedure followed by inoculation on Chrom agar (Oxoid) and Corn Meal-Tween 80 agar (Oxoid). The identification of other non-albicans Candidaspecies was also done both microscopically and macroscopically as per standard procedure. Out of the 289 isolates, 204 (70.6%) were male patients and 85 (29.4%) were female patients, with 165 (57.1%) from the out-patients and 124 (42.9%) from the in-patients. Five species of Candidawere found to be prevalent including 87 (30.1%) Candida albicans, 176 (60.9%) Candida tropicalis, 14 (4.8%) Candida parapsilosis, 8 (2.8%) Candida glabrata and 4 (1.4%) Candida lusitaniae. Majority of patients with funguria were aged above 50 years (60.2%). In the present study, 30.1% patients with funguria had Candida albicans. The most frequently isolated species was Candida tropicalis(60.9%), followed by other non-albicansCandida. This study has shown the emergence of non-albicans Candidaas a major cause of candiduria.

The Candida albicans Ddr48 protein is essential for filamentation, stress response, and confers partial antifungal drug resistance.

PubMed

Dib, Leila; Hayek, Peter; Sadek, Helen; Beyrouthy, Berna; Khalaf, Roy A

2008-06-01

Candida albicans is a dimorphic pathogenic fungus that causes mucosal and systemic infections. C. albicans pathogenicity is attributed to its ability to exist in different morphologic states and to respond to stress by up regulating several key genes. DDR48 is a stress-associated gene involved in DNA repair and in response to antifungal drug exposure. One allele of DDR48 was knocked out by homologous recombination that inserted a marker cassette in its position. Furthermore, reintroducing DDR48 on a plasmid created a revertant strain. Strains were grown on filamentation inducing and noninducing media, subjected to an oxidative stress challenge, injected into mice to assess virulence, and assayed for antifungal susceptibility by the E-test method. DDR48 was found to be haploid insufficient and possibly essential, since only a heterozygote, but not a homozygous, null mutant was generated. The mutant was filamentation defective on all hyphal media tested including serum and corn meal agar. Discrepancies in drug resistance profiles also were present: compared with the parental strain, DDR48/ddr48 heterozygote strain was susceptible in a dose-dependent manner to itraconazole and fluconazole and susceptible to ketoconazole. The mutant also appeared to be hypersensitive to a potentially lethal hydrogen peroxide challenge. However, no reduction in virulence of the mutant was observed. The present findings provide evidence that DDR48 is essential for filamentation, stress response, and possibly viability of C. albicans, making it a prime target for antifungal drug design.

Haemophilus influenzae: an underrated cause of vulvovaginitis in young girls.

PubMed Central

Cox, R A

1997-01-01

AIMS: To establish the common pathogens associated with infective vulvovaginitis in young girls in the local population and to determine current management of this condition. METHODS: A prospective laboratory based survey was carried out over 19 months. A questionnaire was then sent to local general practitioners and hospital doctors. RESULTS: One hundred and six swabs were received during the study period of which 43 (40.5%) yielded organisms recognised as causes of vulvovaginitis. The most common pathogen was group A beta haemolytic streptococcus (19), with Haemophilus influenzae the second most common (11). Candida was isolated on nine occasions. The users' questionnaire had an overall response rate of 52%. Forty one per cent of respondents nominated candida as the most common cause of this condition. Forty six per cent were aware that beta haemolytic streptococci caused juvenile vulvovaginitis, but only four (3.6%) knew that H influenzae was a possible pathogen. The most popular agent for empirical treatment of vulvovaginitis was topical clotrimazole cream, although 24 respondents (22%) prescribed antibiotics that are active against both group A beta haemolytic streptococci and H influenzae. CONCLUSIONS: Although H influenzae is the second most common infective cause of juvenile vulvovaginitis in the local population, most doctors managing these patients were unaware of its importance and may not be prescribing appropriate empirical treatment. Images PMID:9389978

Cross-kingdom interactions: Candida albicans and bacteria.

PubMed

Shirtliff, Mark E; Peters, Brian M; Jabra-Rizk, Mary Ann

2009-10-01

Bacteria and fungi are found together in a myriad of environments and particularly in a biofilm, where adherent species interact through diverse signaling mechanisms. Yet, despite billions of years of coexistence, the area of research exploring fungal-bacterial interactions, particularly within the context of polymicrobial infections, is still in its infancy. However, reports describing a multitude of wide-ranging interactions between the fungal pathogen Candida albicans and various bacterial pathogens are on the rise. An example of a mutually beneficial interaction is coaggregation, a phenomenon that takes place in oral biofilms where the adhesion of C. albicans to oral bacteria is considered crucial for its colonization of the oral cavity. In contrast, the interaction between C. albicans and Pseudomonas aeruginosa is described as being competitive and antagonistic in nature. Another intriguing interaction is that occurring between Staphylococcus aureus and C. albicans, which although not yet fully characterized, appears to be initially synergistic. These complex interactions between such diverse and important pathogens would have significant clinical implications if they occurred in an immunocompromised host. Therefore, understanding the mechanisms of adhesion and signaling involved in fungal-bacterial interactions may lead to the development of novel therapeutic strategies for impeding microbial colonization and development of polymicrobial disease. © 2009 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Candida albicans Pathogenesis: Fitting within the Host-Microbe Damage Response Framework

PubMed Central

Kong, Eric F.; Tsui, Christina; Nguyen, M. Hong; Clancy, Cornelius J.; Fidel, Paul L.; Noverr, Mairi

2016-01-01

Historically, the nature and extent of host damage by a microbe were considered highly dependent on virulence attributes of the microbe. However, it has become clear that disease is a complex outcome which can arise because of pathogen-mediated damage, host-mediated damage, or both, with active participation from the host microbiota. This awareness led to the formulation of the damage response framework (DRF), a revolutionary concept that defined microbial virulence as a function of host immunity. The DRF outlines six classifications of host damage outcomes based on the microbe and the strength of the immune response. In this review, we revisit this concept from the perspective of Candida albicans, a microbial pathogen uniquely adapted to its human host. This fungus commonly colonizes various anatomical sites without causing notable damage. However, depending on environmental conditions, a diverse array of diseases may occur, ranging from mucosal to invasive systemic infections resulting in microbe-mediated and/or host-mediated damage. Remarkably, C. albicans infections can fit into all six DRF classifications, depending on the anatomical site and associated host immune response. Here, we highlight some of these diverse and site-specific diseases and how they fit the DRF classifications, and we describe the animal models available to uncover pathogenic mechanisms and related host immune responses. PMID:27430274

Single-cell force spectroscopy of the medically important Staphylococcus epidermidis-Candida albicans interaction

NASA Astrophysics Data System (ADS)

Beaussart, Audrey; Herman, Philippe; El-Kirat-Chatel, Sofiane; Lipke, Peter N.; Kucharíková, Soňa; van Dijck, Patrick; Dufrêne, Yves F.

2013-10-01

Despite the clinical importance of bacterial-fungal interactions, their molecular details are poorly understood. A hallmark of such medically important interspecies associations is the interaction between the two nosocomial pathogens Staphylococcus aureus and Candida albicans, which can lead to mixed biofilm-associated infections with enhanced antibiotic resistance. Here, we use single-cell force spectroscopy (SCFS) to quantify the forces engaged in bacterial-fungal co-adhesion, focusing on the poorly investigated S. epidermidis-C. albicans interaction. Force curves recorded between single bacterial and fungal germ tubes showed large adhesion forces (~5 nN) with extended rupture lengths (up to 500 nm). By contrast, bacteria poorly adhered to yeast cells, emphasizing the important role of the yeast-to-hyphae transition in mediating adhesion to bacterial cells. Analysis of mutant strains altered in cell wall composition allowed us to distinguish the main fungal components involved in adhesion, i.e. Als proteins and O-mannosylations. We suggest that the measured co-adhesion forces are involved in the formation of mixed biofilms, thus possibly as well in promoting polymicrobial infections. In the future, we anticipate that this SCFS platform will be used in nanomedicine to decipher the molecular mechanisms of a wide variety of pathogen-pathogen interactions and may help in designing novel anti-adhesion agents.

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

Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

PubMed

Palková, Zdena; Váchová, Libuše

2016-09-01

Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

Photodynamic inactivation of pathogenic species Pseudomonas aeruginosa and Candida albicans with lutetium (III) acetate phthalocyanines and specific light irradiation.

PubMed

Mantareva, Vanya; Kussovski, Vesselin; Durmuş, Mahmut; Borisova, Ekaterina; Angelov, Ivan

2016-11-01

Photodynamic inactivation (PDI) is a light-associated therapeutic approach suitable for treatment of local acute infections. The method is based on specific light-activated compound which by specific irradiation and in the presence of molecular oxygen produced molecular singlet oxygen and other reactive oxygen species, all toxic for pathogenic microbial cells. The study presents photodynamic impact of two recently synthesized water-soluble cationic lutetium (III) acetate phthalocyanines (LuPc-5 and LuPc-6) towards two pathogenic strains, namely, the Gram-negative bacterium Pseudomonas aeruginosa and a fungus Candida albicans. The photodynamic effect was evaluated for the cells in suspensions and organized in 48-h developed biofilms. The relatively high levels of uptakes of LuPc-5 and LuPc-6 were determined for fungal cells compared to bacterial cells. The penetration depths and distribution of both LuPcs into microbial biofilms were investigated by means of confocal fluorescence microscopy. The photoinactivation efficiency was studied for a wide concentration range (0.85-30 μM) of LuPc-5 and LuPc-6 at a light dose of 50 J cm -2 from red light-emitting diode (LED; 665 nm). The PDI study on microbial biofilms showed incomplete photoinactivation (<3 logs) for the used gentle drug-light protocol.

Streptococcus agalactiae: a vaginal pathogen?

PubMed

Maniatis, A N; Palermos, J; Kantzanou, M; Maniatis, N A; Christodoulou, C; Legakis, N J

1996-03-01

The significance of Streptococcus agalactiae as an aetiological agent in vaginitis was evaluated. A total of 6226 samples from women who presented with vaginal symptoms was examined. The presence of >10 leucocytes/high-power field (h.p.f.) was taken to be the criterion of active infection. S. agalactiae was isolated from 10.1% of these samples. The isolation rates of other common pathogens such as Candida spp., Gardnerella vaginalis and Trichomonas spp. were 54.1%, 27.2% and 4.2%, respectively, in the same group of patients. In contrast, the isolation rates of these micro-organisms in the group of patients who had no infection (<10 leucocytes/h.p.f.) were 4.2%, 38.3%, 33% and 0.5%, respectively. In the majority of samples from which S. agalactiae was isolated, it was the sole pathogen isolated (83%) and its presence was associated with an inflammatory response in 80% of patients. Furthermore, the relative risk of vaginal infection with S. agalactiae (2.38) in patients with purulent vaginal discharge was greater than that of Candida spp. infection (1.41) and lower than that of Trichomonas spp. infection (8.32). These data suggest that S. agalactiae in symptomatic women with microscopic evidence of inflammation should be considered a causative agent of vaginitis.

Epidemiology and Resistance Patterns of Bacterial and Fungal Colonization of Biliary Plastic Stents: A Prospective Cohort Study

PubMed Central

Lübbert, Christoph; Wendt, Karolin; Feisthammel, Jürgen; Moter, Annette; Lippmann, Norman; Busch, Thilo; Mössner, Joachim; Hoffmeister, Albrecht; Rodloff, Arne C.

2016-01-01

Background Plastic stents used for the treatment of biliary obstruction will become occluded over time due to microbial colonization and formation of biofilms. Treatment of stent-associated cholangitis is often not effective because of inappropriate use of antimicrobial agents or antimicrobial resistance. We aimed to assess the current bacterial and fungal etiology of stent-associated biofilms, with particular emphasis on antimicrobial resistance. Methods Patients with biliary strictures requiring endoscopic stent placement were prospectively enrolled. After the retrieval of stents, biofilms were disrupted by sonication, microorganisms were cultured, and isolates were identified by matrix-associated laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and/or biochemical typing. Finally, minimum inhibitory concentrations (MICs) were determined for various antimicrobial agents. Selected stents were further analyzed by fluorescence in situ hybridization (FISH). Results Among 120 patients (62.5% males, median age 64 years) with biliary strictures (35% malignant, 65% benign), 113 double pigtail polyurethane and 100 straight polyethylene stents were analyzed after a median indwelling time of 63 days (range, 1–1274 days). The stent occlusion rate was 11.5% and 13%, respectively, being associated with a significantly increased risk of cholangitis (38.5% vs. 9.1%, P<0.001). Ninety-five different bacterial and 13 fungal species were detected; polymicrobial colonization predominated (95.8% vs. 4.2%, P<0.001). Enterococci (79.3%), Enterobacteriaceae (73.7%), and Candida spp. (55.9%) were the leading pathogens. Candida species were more frequent in patients previously receiving prolonged antibiotic therapy (63% vs. 46.7%, P = 0.023). Vancomycin-resistant enterococci accounted for 13.7%, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae with co-resistance to ciprofloxacin accounted for 13.9%, and azole-resistant Candida spp. accounted for 32.9% of the respective isolates. Conclusions Enterococci and Candida species play an important role in the microbial colonization of biliary stents. Therefore, empirical antimicrobial treatment of stent-associated cholangitis should be guided toward enterococci, Enterobacteriaceae, streptococci, anaerobes, and Candida. To determine causative pathogens, an accurate microbiological analysis of the extracted stent(s) may be helpful. PMID:27171497

Epidemiology and Resistance Patterns of Bacterial and Fungal Colonization of Biliary Plastic Stents: A Prospective Cohort Study.

PubMed

Lübbert, Christoph; Wendt, Karolin; Feisthammel, Jürgen; Moter, Annette; Lippmann, Norman; Busch, Thilo; Mössner, Joachim; Hoffmeister, Albrecht; Rodloff, Arne C

2016-01-01

Plastic stents used for the treatment of biliary obstruction will become occluded over time due to microbial colonization and formation of biofilms. Treatment of stent-associated cholangitis is often not effective because of inappropriate use of antimicrobial agents or antimicrobial resistance. We aimed to assess the current bacterial and fungal etiology of stent-associated biofilms, with particular emphasis on antimicrobial resistance. Patients with biliary strictures requiring endoscopic stent placement were prospectively enrolled. After the retrieval of stents, biofilms were disrupted by sonication, microorganisms were cultured, and isolates were identified by matrix-associated laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and/or biochemical typing. Finally, minimum inhibitory concentrations (MICs) were determined for various antimicrobial agents. Selected stents were further analyzed by fluorescence in situ hybridization (FISH). Among 120 patients (62.5% males, median age 64 years) with biliary strictures (35% malignant, 65% benign), 113 double pigtail polyurethane and 100 straight polyethylene stents were analyzed after a median indwelling time of 63 days (range, 1-1274 days). The stent occlusion rate was 11.5% and 13%, respectively, being associated with a significantly increased risk of cholangitis (38.5% vs. 9.1%, P<0.001). Ninety-five different bacterial and 13 fungal species were detected; polymicrobial colonization predominated (95.8% vs. 4.2%, P<0.001). Enterococci (79.3%), Enterobacteriaceae (73.7%), and Candida spp. (55.9%) were the leading pathogens. Candida species were more frequent in patients previously receiving prolonged antibiotic therapy (63% vs. 46.7%, P = 0.023). Vancomycin-resistant enterococci accounted for 13.7%, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae with co-resistance to ciprofloxacin accounted for 13.9%, and azole-resistant Candida spp. accounted for 32.9% of the respective isolates. Enterococci and Candida species play an important role in the microbial colonization of biliary stents. Therefore, empirical antimicrobial treatment of stent-associated cholangitis should be guided toward enterococci, Enterobacteriaceae, streptococci, anaerobes, and Candida. To determine causative pathogens, an accurate microbiological analysis of the extracted stent(s) may be helpful.

Immunomodulatory effects and anti-Candida activity of lactobacilli in macrophages and in invertebrate model of Galleria mellonella.

PubMed

de Oliveira, Felipe Eduardo; Rossoni, Rodnei Dennis; de Barros, Patricia Pimentel; Begnini, Barbara Evelyn; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso; Leão, Mariella Vieira Pereira; de Oliveira, Luciane Dias

2017-09-01

Due to the growing number of multi-resistant Candida spp., adjuvant treatments that may help combat these fungal pathogens are relevant and useful. This study evaluated the immunomodulation and anti-Candida activity of Lactobacillus rhamnosus (LR), Lactobacillus acidophilus and Lactobacillus paracasei suspensions, either single- or multiple-strain, in mouse macrophages (RAW 264.7) and Galleria mellonella (GM). Mouse macrophages were activated by different lactobacilli suspensions and challenged with C. albicans (CA). Tumor necrosis factor (TNF)-α, interleukin IL-1β, IL-6 and IL-17 production and cell viability were investigated. LR was the best suspension for stimulating all evaluated cytokines and thus was used in subsequent in vivo assays. Two C. albicans clinical strains, CA21 and CA60, were then added to the GM assays to further confirm the results. LR suspension was injected into the larvae 24 h before challenging with CA. Survival curve, CFU per larva and hemocytes were counted. In the GM, the LR suspension increased the survival rate and hemocyte counts and decreased the CFU per larva counts for all groups. Lactobacilli suspensions presented strain-dependent immunomodulation; however, single suspensions showed better results. Anti-Candida activity was demonstrated by decreased Candida counts in the GM with the use of LR. Copyright © 2017 Elsevier Ltd. All rights reserved.

AFM force spectroscopy reveals how subtle structural differences affect the interaction strength between Candida albicans and DC-SIGN.

PubMed

te Riet, Joost; Reinieren-Beeren, Inge; Figdor, Carl G; Cambi, Alessandra

2015-11-01

The fungus Candida albicans is the most common cause of mycotic infections in immunocompromised hosts. Little is known about the initial interactions between Candida and immune cell receptors, such as the C-type lectin dendritic cell-specific intracellular cell adhesion molecule-3 (ICAM-3)-grabbing non-integrin (DC-SIGN), because a detailed characterization at the structural level is lacking. DC-SIGN recognizes specific Candida-associated molecular patterns, that is, mannan structures present in the cell wall of Candida. The molecular recognition mechanism is however poorly understood. We postulated that small differences in mannan-branching may result in considerable differences in the binding affinity. Here, we exploit atomic force microscope-based dynamic force spectroscopy with single Candida cells to gain better insight in the carbohydrate recognition capacity of DC-SIGN. We demonstrate that slight differences in the N-mannan structure of Candida, that is, the absence or presence of a phosphomannan side chain, results in differences in the recognition by DC-SIGN as follows: (i) it contributes to the compliance of the outer cell wall of Candida, and (ii) its presence results in a higher binding energy of 1.6 kB T. The single-bond affinity of tetrameric DC-SIGN for wild-type C. albicans is ~10.7 kB T and a dissociation constant kD of 23 μM, which is relatively strong compared with other carbohydrate-protein interactions described in the literature. In conclusion, this study shows that DC-SIGN specifically recognizes mannan patterns on C. albicans with high affinity. Knowledge on the binding pocket of DC-SIGN and its pathogenic ligands will lead to a better understanding of how fungal-associated carbohydrate structures are recognized by receptors of the immune system and can ultimately contribute to the development of new anti-fungal drugs. Copyright © 2015 John Wiley & Sons, Ltd.

Multicenter surveillance of species distribution and antifungal susceptibilities of Candida bloodstream isolates in South Korea.

PubMed

Jung, Sook-In; Shin, Jong Hee; Song, Jae-Hoon; Peck, Kyong Ran; Lee, Kyungwon; Kim, Mi-Na; Chang, Hyun Ha; Moon, Chi Sook

2010-06-01

Multicenter data on in vitro susceptibility of Candida bloodstream isolates to echinocandin antifungal agents is still lacking in South Korea. We performed a prospective multicenter study to determine the species distribution of Candida bloodstream isolates and their susceptibility to five antifungal agents, including caspofungin and micafungin. A total of 639 isolates were collected from 20 tertiary hospitals between September 2006 and August 2007. Antifungal susceptibilities were determined through the use of the CLSI broth microdilution method M27-A3. The overall species distribution was as follows; Candida albicans (38%), Candida parapsilosis (26%), Candia tropicalis (20%), Candida glabrata (11%), and miscellaneous Candida species (5%). Although C. parapsilosis and miscellaneous Candida species were less susceptible to both echinocandins, all 639 isolates were susceptible to both caspofungin and micafungin (MIC,

Diffusible signal factor-dependent quorum sensing in pathogenic bacteria and its exploitation for disease control.

PubMed

Dow, J M

2017-01-01

Cell-to-cell signals of the diffusible signal factor (DSF) family are cis-2-unsaturated fatty acids of differing chain length and branching pattern. DSF signalling has been described in diverse bacteria to include plant and human pathogens where it acts to regulate functions such as biofilm formation, antibiotic tolerance and the production of virulence factors. DSF family signals can also participate in interspecies signalling with other bacteria and interkingdom signalling such as with the yeast Candida albicans. Interference with DSF signalling may afford new opportunities for the control of bacterial disease. Such strategies will depend in part on detailed knowledge of the molecular mechanisms underlying the processes of signal synthesis, perception and turnover. Here, I review both recent progress in understanding DSF signalling at the molecular level and prospects for translating this knowledge into approaches for disease control. © 2016 The Society for Applied Microbiology.

Calcineurin Controls Hyphal Growth, Virulence, and Drug Tolerance of Candida tropicalis

PubMed Central

Yu, Shang-Jie; Huang, Hsin-Yu; Chang, Ya-Lin; Lehman, Virginia N.; Silao, Fitz Gerald S.; Bigol, Ursela G.; Bungay, Alice Alma C.; Averette, Anna

2014-01-01

Candida tropicalis, a species closely related to Candida albicans, is an emerging fungal pathogen associated with high mortality rates of 40 to 70%. Like C. albicans and Candida dubliniensis, C. tropicalis is able to form germ tubes, pseudohyphae, and hyphae, but the genes involved in hyphal growth machinery and virulence remain unclear in C. tropicalis. Recently, echinocandin- and azole-resistant C. tropicalis isolates have frequently been isolated from various patients around the world, making treatment difficult. However, studies of the C. tropicalis genes involved in drug tolerance are limited. Here, we investigated the roles of calcineurin and its potential target, Crz1, for core stress responses and pathogenesis in C. tropicalis. We demonstrate that calcineurin and Crz1 are required for hyphal growth, micafungin tolerance, and virulence in a murine systemic infection model, while calcineurin but not Crz1 is essential for tolerance of azoles, caspofungin, anidulafungin, and cell wall-perturbing agents, suggesting that calcineurin has both Crz1-dependent and -independent functions in C. tropicalis. In addition, we found that calcineurin and Crz1 have opposite roles in controlling calcium tolerance. Calcineurin serves as a negative regulator, while Crz1 plays a positive role for calcium tolerance in C. tropicalis. PMID:24442892

Identification and susceptibility of clinical isolates of Candida spp. to killer toxins.

PubMed

Robledo-Leal, E; Rivera-Morales, L G; Sangorrín, M P; González, G M; Ramos-Alfano, G; Adame-Rodriguez, J M; Alcocer-Gonzalez, J M; Arechiga-Carvajal, E T; Rodriguez-Padilla, C

2018-02-01

Although invasive infections and mortality caused by Candida species are increasing among compromised patients, resistance to common antifungal agents is also an increasing problem. We analyzed 60 yeasts isolated from patients with invasive candidiasis using a PCR/RFLP strategy based on the internal transcribed spacer (ITS2) region to identify different Candida pathogenic species. PCR analysis was performed from genomic DNA with a primer pair of the ITS2-5.8S rDNA region. PCR-positive samples were characterized by RFLP. Restriction resulted in 23 isolates identified as C. albicans using AlwI, 24 isolates as C. parapsilosis using RsaI, and 13 as C. tropicalis using XmaI. Then, a group of all isolates were evaluated for their susceptibility to a panel of previously described killer yeasts, resulting in 75% being susceptible to at least one killer yeast while the remaining were not inhibited by any strain. C. albicans was the most susceptible group while C. tropicalis had the fewest inhibitions. No species-specific pattern of inhibition was obtained with this panel of killer yeasts. Metschnikowia pulcherrima, Pichia kluyveri and Wickerhamomyces anomalus were the strains that inhibited the most isolates of Candida spp.

Functional Assignment of YvgO, a Novel Set of Purified and Chemically Characterized Proteinaceous Antifungal Variants Produced by Bacillus thuringiensis SF361

PubMed Central

Manns, David C.; Churey, John J.

2012-01-01

This study reports a novel class of antifungal protein derived from bacterial origin. Bacillus thuringiensis SF361, the strain also responsible for producing the novel bacteriocin thurincin H, exhibits broad antifungal activity against select members of several fungal genera, including Aspergillus, Byssochlamys, and Penicillium, as well as the pathogenic yeast Candida albicans. Optimal antifungal production and secretion were observed after-log phase growth when incubated at 37°C in a carbohydrate-free growth medium. High-performance liquid chromatography purification was performed after pH-selective ammonium sulfate precipitation and size-exclusion chromatography. Intact mass analysis and peptide mass fingerprinting identified the 13,484-Da protein to be a mass homolog to the YvgO protein construct sequenced from Bacillus cereus AH 1134. Further analysis via amino-terminal sequencing also revealed the existence of four distinct yet equally efficacious YvgO variants differing only within the first four N-terminal residues. YvgO was found to be remarkably stable, maintaining its antifungal activity under a wide pH and temperature range. When assayed against the toxigenic species Byssochlamys fulva H25, the selected primary filamentous fungal indicator, the MIC was estimated to be 1.5 ppm. Candida albicans 3153 was more resistant, exhibiting MICs between 25 and 800 ppm, depending on growth conditions. YvgO is unique among antifungals, showing no known sequential or functional homology to the typical classes of antifungal proteins, including common membrane-acting agents such as cellulases and glucanases. Due to its activity against an array of pathogenic and spoilage fungi, the potentials for clinical, agricultural, and food-processing applications are encouraging. PMID:22307285

Management of Candida biofilms: state of knowledge and new options for prevention and eradication.

PubMed

Bujdáková, Helena

2016-01-01

Biofilms formed by Candida species (spp.) on medical devices represent a potential health risk. The focus of current research is searching for new options for the treatment and prevention of biofilm-associated infections using different approaches including modern nanotechnology. This review summarizes current information concerning the most relevant resistance/tolerance mechanisms to conventional drugs and a role of additional factors contributing to these phenomena in Candida spp. (mostly Candida albicans). Additionally, it provides an information update in prevention and eradication of a Candida biofilm including experiences with 'lock' therapy, potential utilization of small molecules in biomedical applications, and perspectives of using photodynamic inactivation in the control of a Candida biofilm.

Comparing the efficacy of hyper-pure chlorine-dioxide with other oral antiseptics on oral pathogen microorganisms and biofilm in vitro.

PubMed

Herczegh, Anna; Gyurkovics, Milán; Agababyan, Hayk; Ghidán, Agoston; Lohinai, Zsolt

2013-09-01

This study examines the antibacterial properties of sodium hypochlorite (NaOCl), chlorhexidine gluconate (CHX), Listerine®, and high purity chlorine dioxide (Solumium, ClO2) on selected common oral pathogen microorganisms and on dental biofilm in vitro. Antimicrobial activity of oral antiseptics was compared to the gold standard phenol. We investigated Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, Veillonella alcalescens, Eikenella corrodens, Actinobacillus actinomycetemcomitans and Candida albicans as some important representatives of the oral pathogens. Furthermore, we collected dental plaque from the upper first molars of healthy young students. Massive biofilm was formed in vitro and its reduction was measured after treating it with mouthrinses: CHX, Listerine® or hyper pure ClO2. Their biofilm disrupting effect was measured after dissolving the crystal violet stain from biofilm by photometer. The results have showed that hyper pure ClO2 solution is more effective than other currently used disinfectants in case of aerobic bacteria and Candida yeast. In case of anaerobes its efficiency is similar to CHX solution. The biofilm dissolving effect of hyper pure ClO2 is significantly stronger compared to CHX and Listerine® after 5 min treatment. In conclusion, hyper pure ClO2 has a potent disinfectant efficacy on oral pathogenic microorganisms and a powerful biofilm dissolving effect compared to the current antiseptics, therefore high purity ClO2 may be a new promising preventive and therapeutic adjuvant in home oral care and in dental or oral surgery practice.

Inhibitory effects of Lactobacillus rhamnosus and Lactobacillus casei on Candida biofilm of denture surface.

PubMed

Song, Young-Gyun; Lee, Sung-Hoon

2017-04-01

Candida albicans biofilm is associated with denture-related stomatitis and oral candidiasis of elderly. Probiotics are beneficial bacteria and have antibacterial activity against pathogenic bacteria. The purpose of this study was to investigate the antifungal activity of various probiotics against C. albicans and the inhibitory effects of probiotics on Candida biofilm on the denture surface. The spent culture media of various probiotics were investigated the antifungal efficacy against C. albicans. Candida biofilm was formed on a denture base resin and was then treated with Lactobacillus rhamnosus and Lactobacillus casei. Also, the biofilms of L. rhamnosus and L. casei were formed and were sequentially treated with C. albicans. Colony-forming units of C. albicans on the denture surface were counted after spreading on agar plate. The denture base resin was treated with the spent culture media for 30days, after which the denture surface roughness was analyzed with an atomic force microscope. L. rhamnosus and L. casei exhibited stronger antifungal activity than other probiotics. The spent culture medium of L. rhamnosus and L. casei exhibited the antifungal activity against blastoconidia and biofilm of C. albicans. L. rhamnosus and L. casei showed the antifungal activity against Candida biofilm, and the biofilm of L. rhamnosus and L. casei inhibited formation of Candida biofilm on denture surface. Neither of the probiotics affected the surface roughness of the denture base resin. L. rhamnosus and L. casei may be the ideal probiotics for the prevention and treatment of denture-related stomatitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of Candida species isolated from children with and without early childhood caries: A descriptive cross-sectional study.

PubMed

Beena, M S; Peedikayil, Faizal C; GufranAfmed, M B; Chandru, T P; Soni, K; Dhanesh, N

2017-01-01

Early childhood caries (ECC) is characterized by the presence of one or more decayed, missing (due to caries), or filled teeth surfaces in any primary tooth, in a child below 6 years of age. Although ECC is primarily associated with high levels of maternal Streptococcus mutans, there has been an increased interest in finding the relationship between oral fungal flora and dental caries. The aim of the study is to identify and characterize the Candida species and to compare the candidal isolates in children with ECC and without ECC. The study was conducted on children below 6 years of age, who were categorized into ECC and non-ECC groups of fifty children each. Samples were collected using sterile cotton swabs and were inoculated on Sabouraud's Dextrose Agar and incubated at 37°C for 24 h. Candidal colonies were isolated, species identified and virulence factors tested for both ECC and non-ECC groups. The candidal carriage among the ECC children was found to be 84%, which was significantly higher than the non-ECC group of 24%. Candida albicans and non-albicans Candida (NAC) were isolated in both ECC and non-ECC groups. Phospholipase production was significantly high in ECC group whereas hemolysin production and germ tube formation showed no significant difference between the two groups. A significant correlation was found between the presence of Candida and ECC. NAC also plays an important role in the development of ECC. The virulence factors such as phospholipase may be responsible for the pathogenicity of Candida in the development of ECC.

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

May one-stage exchange for Candida albicans peri-prosthetic infection be successful?

PubMed

Jenny, J-Y; Goukodadja, O; Boeri, C; Gaudias, J

2016-02-01

Fungal infection of a total joint arthroplasty has a low incidence but is generally considered as more difficult to cure than bacterial infection. As for bacterial infection, two-stage exchange is considered as the gold standard of treatment. We report two cases of one-stage total joint exchange for fungal peri-prosthetic infection with Candida albicans, where the responsible pathogens was only identified on intraoperative samples. This situation can be considered as a one-stage exchange for fungal peri-prosthetic infection without preoperative identification of the responsible organism, which is considered as having a poor prognosis. Both cases were free of infection after two years. One-stage revision has several potential advantages over two-stage revision, including shorter hospital stay and rehabilitation, no interim period with significant functional impairment, shorter antibiotic treatment, better functional outcome and probably lower costs. We suggest that one-stage revision for C. albicans peri-prosthetic infection may be successful even without preoperative fungal identification. Level IV-Historical cases. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Genetic structure of typical and atypical populations of Candida albicans from Africa.

PubMed

Forche, A; Schönian, G; Gräser, Y; Vilgalys, R; Mitchell, T G

1999-11-01

Atypical isolates of the pathogenic yeast Candida albicans have been reported with increasing frequency. To investigate the origin of a set of atypical isolates and their relationship to typical isolates, we employed a combination of molecular phylogenetic and population genetic analyses using rDNA sequencing, PCR fingerprinting, and analysis of co-dominant DNA nucleotide polymorphisms to characterize the population structure of one typical and two atypical populations of C. albicans from Angola and Madagascar. The extent of clonality and recombination was assessed in each population. The analyses revealed that the structure of all three populations of C. albicans was predominantly clonal but, as in previous studies, there was also evidence for recombination. Allele frequencies differed significantly between the typical and the atypical populations, suggesting very low levels of gene flow between them. However, allele frequencies were quite similar in the two atypical C. albicans populations, suggesting that they are closely related. Phylogenetic analysis of partial sequences encoding the nuclear 26S rDNA demonstrated that all three populations belong to a single monophyletic group, which includes the type strain of C. albicans. Copyright 1999 Academic Press.

Validation of High Resolution Melting Analysis (HRM) of the Amplified ITS2 Region for the Detection and Identification of Yeasts from Clinical Samples: Comparison with Culture and MALDI-TOF Based Identification.

PubMed

Duyvejonck, Hans; Cools, Piet; Decruyenaere, Johan; Roelens, Kristien; Noens, Lucien; Vermeulen, Stefan; Claeys, Geert; Decat, Ellen; Van Mechelen, Els; Vaneechoutte, Mario

2015-01-01

Candida species are known as opportunistic pathogens, and a possible cause of invasive infections. Because of their species-specific antimycotic resistance patterns, reliable techniques for their detection, quantification and identification are needed. We validated a DNA amplification method for direct detection of Candida spp. from clinical samples, namely the ITS2-High Resolution Melting Analysis (direct method), by comparing it with a culture and MALDI-TOF Mass Spectrometry based method (indirect method) to establish the presence of Candida species in three different types of clinical samples. A total of 347 clinical samples, i.e. throat swabs, rectal swabs and vaginal swabs, were collected from the gynaecology/obstetrics, intensive care and haematology wards at the Ghent University Hospital, Belgium. For the direct method, ITS2-HRM was preceded by NucliSENS easyMAG DNA extraction, directly on the clinical samples. For the indirect method, clinical samples were cultured on Candida ID and individual colonies were identified by MALDI-TOF. For 83.9% of the samples there was complete concordance between both techniques, i.e. the same Candida species were detected in 31.1% of the samples or no Candida species were detected in 52.8% of the samples. In 16.1% of the clinical samples, discrepant results were obtained, of which only 6.01% were considered as major discrepancies. Discrepancies occurred mostly when overall numbers of Candida cells in the samples were low and/or when multiple species were present in the sample. Most of the discrepancies could be decided in the advantage of the direct method. This is due to samples in which no yeast could be cultured whereas low amounts could be detected by the direct method and to samples in which high quantities of Candida robusta according to ITS2-HRM were missed by culture on Candida ID agar. It remains to be decided whether the diagnostic advantages of the direct method compensate for its disadvantages.

Complete genome sequence of Lactobacillus plantarum LZ206, a potential probiotic strain with antimicrobial activity against food-borne pathogenic microorganisms.

PubMed

Li, Ping; Gu, Qing; Zhou, Qingqing

2016-11-20

Lactobacilli strains have been considered as important candidates for manufacturing "natural food", due to their antimicrobial properties and generally regarded as safe (GRAS) status. Lactobacillus plantarum LZ206 is a potential probiotic strain isolated from raw cow milk, with antimicrobial activity against various pathogens, including Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes), Gram-negtive bacteria (Escherichia coli and Salmonella enterica), and fungus Candida albicans. To better understand molecular base for its antimicrobial activity, entire genome of LZ206 was sequenced. It was revealed that genome of LZ206 contained a circular 3,212,951-bp chromosome, two circular plasmids and one predicted linear plasmid. A plantaricin gene cluster, which is responsible for bacteriocins biosynthesis and could be associated with its broad-spectrum antimicrobial activity, was identified based on comparative genomic analysis. Whole genome sequencing of L. plantarum LZ206 might facilitate its applications to protect food products from pathogens' contamination in the dairy industry. Copyright © 2016 Elsevier B.V. All rights reserved.

High frame-rate resolution of cell division during Candida albicans filamentation

PubMed Central

Thomson, Darren D.; Berman, Judith; Brand, Alexandra C.

2016-01-01

The commensal yeast, Candida albicans, is an opportunistic pathogen in humans and forms filaments called hyphae and pseudohyphae, in which cell division requires precise temporal and spatial control to produce mononuclear cell compartments. High-frame-rate live-cell imaging (1 frame/min) revealed that nuclear division did not occur across the septal plane. We detected the presence of nucleolar fragments that may be extrachromosomal molecules carrying the ribosomal RNA genes. Cells occasionally maintained multiple nucleoli, suggesting either polyploidy, multiple nuclei and/or aneuploidy of ChrR., while the migration pattern of sister nuclei differed between unbranched and branched hyphae. The presented movie challenges and extends previous concepts of C. albicans cell division. PMID:26854071

Surface disinfection challenges for Candida auris: an in-vitro study.

PubMed

Kean, R; Sherry, L; Townsend, E; McKloud, E; Short, B; Akinbobola, A; Mackay, W G; Williams, C; Jones, B L; Ramage, G

2018-04-01

The emerging pathogenic multidrug-resistant yeast Candida auris is an important source of healthcare-associated infections and of growing global clinical concern. The ability of this organism to survive on surfaces and withstand environmental stressors creates a challenge for eradicating it from hospitals. A panel of C. auris clinical isolates was evaluated on different surface environments against the standard disinfectant sodium hypochlorite and high-level disinfectant peracetic acid. C. auris was shown to selectively tolerate clinically relevant concentrations of sodium hypochlorite and peracetic acid in a surface-dependent manner, which may explain its ability to successfully persist within the hospital environment. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

The mitochondrial genome of the pathogenic yeast Candida subhashii: GC-rich linear DNA with a protein covalently attached to the 5′ termini

PubMed Central

Fricova, Dominika; Valach, Matus; Farkas, Zoltan; Pfeiffer, Ilona; Kucsera, Judit; Tomaska, Lubomir; Nosek, Jozef

2010-01-01

As a part of our initiative aimed at a large-scale comparative analysis of fungal mitochondrial genomes, we determined the complete DNA sequence of the mitochondrial genome of the yeast Candida subhashii and found that it exhibits a number of peculiar features. First, the mitochondrial genome is represented by linear dsDNA molecules of uniform length (29 795 bp), with an unusually high content of guanine and cytosine residues (52.7 %). Second, the coding sequences lack introns; thus, the genome has a relatively compact organization. Third, the termini of the linear molecules consist of long inverted repeats and seem to contain a protein covalently bound to terminal nucleotides at the 5′ ends. This architecture resembles the telomeres in a number of linear viral and plasmid DNA genomes classified as invertrons, in which the terminal proteins serve as specific primers for the initiation of DNA synthesis. Finally, although the mitochondrial genome of C. subhashii contains essentially the same set of genes as other closely related pathogenic Candida species, we identified additional ORFs encoding two homologues of the family B protein-priming DNA polymerases and an unknown protein. The terminal structures and the genes for DNA polymerases are reminiscent of linear mitochondrial plasmids, indicating that this genome architecture might have emerged from fortuitous recombination between an ancestral, presumably circular, mitochondrial genome and an invertron-like element. PMID:20395267

Description of Groenewaldozyma gen. nov. for placement of Candida auringiensis, Candida salmanticensis and Candida tartarivorans.

PubMed

Kurtzman, Cletus P

2016-07-01

DNA sequence analyses have demonstrated that species of the polyphyletic anamorphic ascomycete genus Candida may be members of described teleomorphic genera, members of the Candida tropicalis clade upon which the genus Candida is circumscribed, or members of isolated clades that represent undescribed genera. From phylogenetic analysis of gene sequences from nuclear large subunit rRNA, mitochondrial small subunit rRNA and cytochrome oxidase II, Candida auringiensis (NRRL Y-17674(T), CBS 6913(T)), Candida salmanticensis (NRRL Y-17090(T), CBS 5121(T)), and Candida tartarivorans (NRRL Y-27291(T), CBS 7955(T)) were shown to be members of an isolated clade and are proposed for reclassification in the genus Groenewaldozyma gen. nov. (MycoBank MB 815817). Neighbouring taxa include species of the Wickerhamiella clade and Candida blankii.

Green synthesized zinc oxide nanoparticles as a therapeutic tool to combat candidiasis

NASA Astrophysics Data System (ADS)

Rathod, Tejas; Padalia, Hemali; Chanda, Sumitra

2017-05-01

Advancement of modern medicine, the increasing ratio of immunocompromised and immunosuppressive individuals is increased in hospitalized with serious underlying disease. This has resulted in a rise in the incidence of fungal infections, especially those due to Candida species. For many years the conventional antibiotic therapy has been critical in the fight against Candidiasis. Candidiasis is a fungal infection due to various types of Candida (yeast) species. In this study, zinc oxide nanoparticles (ZnONPs) were synthesized using the Cinnamomum verum bark plus Cassia auriculata leaf powder extracts. The characterization of synthesized ZnONPs was done by UV-Vis spectrophotometer and SEM analysis. The average size of nanoparticles was 77 nm. Synergistic anticandidal activity of ZnONPs (ZnONPs plus antibiotics) was determined by disc diffusion method against 16 multidrug resistant clinical pathogens of Candida species. Antibiotic Ketoconazole plus ZnONPs showed best synergistic anticandidal activity against all the 16 isolates. Green synthesized ZnONPs appears to be a new promising approach to fight against Candidiasis.

Donor Derived Candida stellimalicola in a Clinical Specimen: Preservation Fluid Contamination During Pancreas Procurement.

PubMed

Dupont, Damien; Huguenin, Antoine; Tisserand, Elodie; Reiter, Véronique; Morelon, Emmanuel; Badet, Lionel; Villena, Isabelle; Wallon, Martine; Toubas, Dominique

2018-06-01

We report here a case of possible donor-derived Candida stellimalicola infection after pancreas transplantation. Candida stellimalicola, an environmental non-filamentous yeast, was isolated from both the peritoneal fluid of the graft donor and the preservation fluid of the transplanted pancreas. Interestingly, this strain exhibited high minimum inhibitory concentrations to azoles. These results justified the use of echinocandins as therapy instead of fluconazole. This switch permitted a favorable outcome. To our knowledge, this is the first report of C. stellimalicola from clinical samples and therefore the first reported case of a possible human infection. This case report highlights the need for standardized microbiological procedures in solid organ transplant settings. Moreover, it underlines the importance of using molecular identification technique when routine techniques do not allow successful identification of the pathogen. It is of utmost importance to determine sensitivity profile, even in the absence of species-level identification, because resistance to fluconazole is not uncommon, especially in emergent species.

Candida albicans osteomyelitis of the spine: progressive clinical and radiological features and surgical management in three cases.

PubMed

Khazim, Rabi M; Debnath, Ujjwal K; Fares, Youssef

2006-09-01

Candida albicans vertebral osteomyelitis is rare. Three cases are presented. Without antifungal treatment, they developed spinal collapse and neurological deterioration within 3-6 months from the onset of symptoms. There was a delay of 4.5 and 7.5 months between the onset of symptoms and surgery. All patients were managed with surgical debridement and reconstruction and 12-week fluconazole treatment. The neurological deficits resolved completely. The infection has not recurred clinically or radiologically at 5-6 years follow-up. Although rare, Candida should be suspected as a causative pathogen in cases of spinal osteomyelitis. Without treatment the disease is progressive. As soon as osteomyelitis is suspected, investigations with MRI and percutaneous biopsy should be performed followed by medical therapy. This may prevent the need for surgery. However, if vertebral collapse and spinal cord compression occurs, surgical debridement, fusion and stabilisation combined with antifungal medications can successfully eradicate the infection and resolve the neurological deficits.

Candida albicans osteomyelitis of the spine: progressive clinical and radiological features and surgical management in three cases

PubMed Central

Debnath, Ujjwal K; Fares, Youssef

2006-01-01

Candida albicans vertebral osteomyelitis is rare. Three cases are presented. Without antifungal treatment, they developed spinal collapse and neurological deterioration within 3–6 months from the onset of symptoms. There was a delay of 4.5 and 7.5 months between the onset of symptoms and surgery. All patients were managed with surgical debridement and reconstruction and 12-week fluconazole treatment. The neurological deficits resolved completely. The infection has not recurred clinically or radiologically at 5–6 years follow-up. Although rare, Candida should be suspected as a causative pathogen in cases of spinal osteomyelitis. Without treatment the disease is progressive. As soon as osteomyelitis is suspected, investigations with MRI and percutaneous biopsy should be performed followed by medical therapy. This may prevent the need for surgery. However, if vertebral collapse and spinal cord compression occurs, surgical debridement, fusion and stabilisation combined with antifungal medications can successfully eradicate the infection and resolve the neurological deficits. PMID:16429290

Candida utilis and Cyberlindnera (Pichia) jadinii: yeast relatives with expanding applications.

PubMed

Buerth, Christoph; Tielker, Denis; Ernst, Joachim F

2016-08-01

The yeast Candida utilis is used as a food additive and as a host for heterologous gene expression to produce various metabolites and proteins. Reliable protocols for intracellular production of recombinant proteins are available for C. utilis and have now been expanded to secrete proteins into the growth medium or to achieve surface display by linkage to a cell wall protein. A recombinant C. utilis strain was recently shown to induce oral tolerance in a mouse model of multiple sclerosis suggesting future applications in autoimmune therapy. Whole genome sequencing of C. utilis and its presumed parent Cyberlindnera (Pichia) jadinii demonstrated different ploidy but high sequence identity, consistent with identical recombinant technologies for both yeasts. C. jadinii was recently described as an antagonist to the important human fungal pathogen Candida albicans suggesting its use as a probiotic agent. The review summarizes the status of recombinant protein production in C. utilis, as well as current and future biotechnological and medical applications of C. utilis and C. jadinii.

Antifungal Activity of Decyl Gallate against Several Species of Pathogenic Fungi

PubMed Central

de Paula e Silva, Ana Carolina Alves; Costa-Orlandi, Caroline Barcelos; Gullo, Fernanda Patrícia; Sangalli-Leite, Fernanda; de Oliveira, Haroldo Cesar; da Silva, Julhiany de Fátima; Rossi, Suélen Andrea; Benaducci, Tatiane; Wolf, Vanessa Gonçalves; Regasini, Luis Octávio; Petrônio, Maicon Segalla; Silva, Dulce Helena Siqueira; Bolzani, Vanderlan S.; Mendes-Giannini, Maria José Soares

2014-01-01

This work aims to demonstrate that the gallic acid structure modification to the decyl gallate (G14) compound contributed to increase the antifungal activity against several species of pathogenic fungi, mainly, Candida spp., Cryptococcus spp., Paracoccidioides spp., and Histoplasma capsulatum, according to standardized microdilution method described by Clinical Laboratory Standard Institute (CLSI) documents. Moreover this compound has a particularly good selectivity index value, which makes it an excellent candidate for broad-spectrum antifungal prototype and encourages the continuation of subsequent studies for the discovery of its mechanism of action. PMID:25505923

A Novel Strategy to Control and Prevent Norovirus Gastroenteritis

DTIC Science & Technology

2006-11-01

Vibrio cholerae , Candida, etc.) have been reported to recognize the HBGAs as their receptors. NV is the first viral pathogen in the list. Human...and genogroup II: BUDS (AY660568), Grimsby (GrV; AJ004864), Hawaii (HV; U07611), Mexico (MxV; U22498), MOH (AF397156), Parris Island (PiV

[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.

Enhancement of antidandruff activity of shampoo by biosynthesized silver nanoparticles from Solanum trilobatum plant leaf

NASA Astrophysics Data System (ADS)

Pant, Gaurav; Nayak, Nitesh; Gyana Prasuna, R.

2013-10-01

The present investigation describes simple and effective method for synthesis of silver nanoparticles via green route. Solanum trilobatum Linn extract were prepared by both conventional and homogenization method. We optimized the production of silver nanoparticles under sunlight, microwave and room temperature. The best results were obtained with sunlight irradiation, exhibiting 15-20 nm silver nanoparticles having cubic and hexagonal shape. Biosynthesized nanoparticles were highly toxic to various bacterial strains tested. In this study we report antibacterial activity against various Gram negative ( Klebsiella pneumoniae, Vibrio cholerae and Salmonella typhi) and Gram positive ( Staphylococcus aureus, Bacillus cereus and Micrococcus luteus) bacterial strains. Screening was also performed for any antifungal properties of the nanoparticles against human pathogenic fungal strains ( Candida albicans and Candida parapsilosis). We also demonstrated that these nanoparticles when mixed with shampoo enhance the anti-dandruff effect against dandruff causing fungal pathogens ( Pityrosporum ovale and Pityrosporum folliculitis). The present study showed a simple, rapid and economical route to synthesize silver nanoparticles and their applications hence has a great potential in biomedical field.

Ras-Mediated Signal Transduction and Virulence in Human Pathogenic Fungi

PubMed Central

Fortwendel, Jarrod R.

2013-01-01

Signal transduction pathways regulating growth and stress responses are areas of significant study in the effort to delineate pathogenic mechanisms of fungi. In-depth knowledge of signal transduction events deepens our understanding of how a fungal pathogen is able to sense changes in the environment and respond accordingly by modulation of gene expression and re-organization of cellular activities to optimize fitness. Members of the Ras protein family are important regulators of growth and differentiation in eukaryotic organisms, and have been the focus of numerous studies exploring fungal pathogenesis. Here, the current data regarding Ras signal transduction are reviewed for three major pathogenic fungi: Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus. Particular emphasis is placed on Ras-protein interactions during control of morphogenesis, stress response and virulence. PMID:24855584

The yeast spectrum of the 'tea fungus Kombucha'.

PubMed

Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

1995-01-01

The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably consume controlled commercial Kombucha beverages.

Invasive Fungal Infections in Patients with Hematological Malignancies: Emergence of Resistant Pathogens and New Antifungal Therapies

PubMed Central

Gamaletsou, Maria N.; Walsh, Thomas J.; Sipsas, Nikolaos V.

2018-01-01

Invasive fungal infections caused by drug-resistant organisms are an emerging threat to heavily immunosuppressed patients with hematological malignancies. Modern early antifungal treatment strategies, such as prophylaxis and empirical and preemptive therapy, result in long-term exposure to antifungal agents, which is a major driving force for the development of resistance. The extended use of central venous catheters, the nonlinear pharmacokinetics of certain antifungal agents, neutropenia, other forms of intense immunosuppression, and drug toxicities are other contributing factors. The widespread use of agricultural and industrial fungicides with similar chemical structures and mechanisms of action has resulted in the development of environmental reservoirs for some drug-resistant fungi, especially azole-resistant Aspergillus species, which have been reported from four continents. The majority of resistant strains have the mutation TR34/L98H, a finding suggesting that the source of resistance is the environment. The global emergence of new fungal pathogens with inherent resistance, such as Candida auris, is a new public health threat. The most common mechanism of antifungal drug resistance is the induction of efflux pumps, which decrease intracellular drug concentrations. Overexpression, depletion, and alteration of the drug target are other mechanisms of resistance. Mutations in the ERG11 gene alter the protein structure of C-demethylase, reducing the efficacy of antifungal triazoles. Candida species become echinocandin-resistant by mutations in FKS genes. A shift in the epidemiology of Candida towards resistant non-albicans Candida spp. has emerged among patients with hematological malignancies. There is no definite association between antifungal resistance, as defined by elevated minimum inhibitory concentrations, and clinical outcomes in this population. Detection of genes or mutations conferring resistance with the use of molecular methods may offer better predictive values in certain cases. Treatment options for resistant fungal infections are limited and new drugs with novel mechanisms of actions are needed. Prevention of resistance through antifungal stewardship programs is of paramount importance. PMID:29391334

Distribution of dimorphic yeast species in commercial extra virgin olive oil.

PubMed

Zullo, B A; Cioccia, G; Ciafardini, G

2010-12-01

Recent microbiological research has demonstrated the presence of a rich microflora mainly composed of yeasts in the suspended fraction of freshly produced olive oil. Some of the yeasts are considered useful as they improve the organoleptic characteristics of the oil during preservation, whereas others are considered harmful as they can damage the quality of the oil through the hydrolysis of the triglycerides. However, some dimorphic species can also be found among the unwanted yeasts present in the oil, considered to be opportunistic pathogens to man as they have often been isolated from immunocompromised hospital patients. Present research demonstrates the presence of dimorphic yeast forms in 26% of the commercial extra virgin olive oil originating from different geographical areas, where the dimorphic yeasts are represented by 3-99.5% of the total yeasts. The classified isolates belonged to the opportunistic pathogen species Candida parapsilosis and Candida guilliermondii, while among the dimorphic yeasts considered not pathogenic to man, the Candida diddensiae species was highlighted for the first time in olive oil. The majority of the studied yeast strains resulted lipase positive, and can consequently negatively influence the oil quality through the hydrolysis of the triglycerides. Furthermore, all the strains showed a high level of affinity with some organic solvents and a differing production of biofilm in "vitro" corresponded to a greater or lesser hydrophobia of their cells. Laboratory trials indicated that the dimorphic yeasts studied are sensitive towards some components of the oil among which oleic acid, linoleic acid and triolein, whereas a less inhibiting effect was observed with tricaprilin or when the total polyphenols extracted from the oil were used. The observations carried out on a scanning electron microscope (SEM), demonstrated the production of long un-branched pseudohyphae in all the tested dimorphic yeasts when cultivated on nutrient-deficient substrates. Copyright © 2010 Elsevier Ltd. All rights reserved.

How Often Do They Have Sex? A Comparative Analysis of the Population Structure of Seven Eukaryotic Microbial Pathogens

PubMed Central

Tomasini, Nicolás; Lauthier, Juan José; Ayala, Francisco José; Tibayrenc, Michel; Diosque, Patricio

2014-01-01

The model of predominant clonal evolution (PCE) proposed for micropathogens does not state that genetic exchange is totally absent, but rather, that it is too rare to break the prevalent PCE pattern. However, the actual impact of this “residual” genetic exchange should be evaluated. Multilocus Sequence Typing (MLST) is an excellent tool to explore the problem. Here, we compared online available MLST datasets for seven eukaryotic microbial pathogens: Trypanosoma cruzi, the Fusarium solani complex, Aspergillus fumigatus, Blastocystis subtype 3, the Leishmania donovani complex, Candida albicans and Candida glabrata. We first analyzed phylogenetic relationships among genotypes within each dataset. Then, we examined different measures of branch support and incongruence among loci as signs of genetic structure and levels of past recombination. The analyses allow us to identify three types of genetic structure. The first was characterized by trees with well-supported branches and low levels of incongruence suggesting well-structured populations and PCE. This was the case for the T. cruzi and F. solani datasets. The second genetic structure, represented by Blastocystis spp., A. fumigatus and the L. donovani complex datasets, showed trees with weakly-supported branches but low levels of incongruence among loci, whereby genetic structuration was not clearly defined by MLST. Finally, trees showing weakly-supported branches and high levels of incongruence among loci were observed for Candida species, suggesting that genetic exchange has a higher evolutionary impact in these mainly clonal yeast species. Furthermore, simulations showed that MLST may fail to show right clustering in population datasets even in the absence of genetic exchange. In conclusion, these results make it possible to infer variable impacts of genetic exchange in populations of predominantly clonal micro-pathogens. Moreover, our results reveal different problems of MLST to determine the genetic structure in these organisms that should be considered. PMID:25054834

Indicator microbes correlate with pathogenic bacteria, yeasts and helminthes in sand at a subtropical recreational beach site.

PubMed

Shah, A H; Abdelzaher, A M; Phillips, M; Hernandez, R; Solo-Gabriele, H M; Kish, J; Scorzetti, G; Fell, J W; Diaz, M R; Scott, T M; Lukasik, J; Harwood, V J; McQuaig, S; Sinigalliano, C D; Gidley, M L; Wanless, D; Ager, A; Lui, J; Stewart, J R; Plano, L R W; Fleming, L E

2011-06-01

Research into the relationship between pathogens, faecal indicator microbes and environmental factors in beach sand has been limited, yet vital to the understanding of the microbial relationship between sand and the water column and to the improvement of criteria for better human health protection at beaches. The objectives of this study were to evaluate the presence and distribution of pathogens in various zones of beach sand (subtidal, intertidal and supratidal) and to assess their relationship with environmental parameters and indicator microbes at a non-point source subtropical marine beach. In this exploratory study in subtropical Miami (Florida, USA), beach sand samples were collected and analysed over the course of 6 days for several pathogens, microbial source tracking markers and indicator microbes. An inverse correlation between moisture content and most indicator microbes was found. Significant associations were identified between some indicator microbes and pathogens (such as nematode larvae and yeasts in the genus Candida), which are from classes of microbes that are rarely evaluated in the context of recreational beach use. Results indicate that indicator microbes may predict the presence of some of the pathogens, in particular helminthes, yeasts and the bacterial pathogen Staphylococcus aureus including methicillin-resistant forms. Indicator microbes may thus be useful for monitoring beach sand and water quality at non-point source beaches. The presence of both indicator microbes and pathogens in beach sand provides one possible explanation for human health effects reported at non-point sources beaches. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Boric acid for recurrent vulvovaginal candidiasis: the clinical evidence.

PubMed

Iavazzo, Christos; Gkegkes, Ioannis D; Zarkada, Ioanna M; Falagas, Matthew E

2011-08-01

Recurrent vulvovaginal candidiasis (VVC) remains a challenge to manage in clinical practice. Recent epidemiologic studies indicate that non-albicans Candida spp. are more resistant to conventional antifungal treatment with azoles and are considered as causative pathogens of vulvovaginal candidiasis. We searched PubMed and Scopus for studies that reported clinical evidence on the intravaginal use of boric acid for vulvovaginal candidiasis. We identified 14 studies (2 randomized clinical trials [RCTs], 9 case series, and 4 case reports) as eligible for inclusion in this review. Boric acid was compared with nystatin, terconazole, flucytosine, itraconazole, clotrimazole, ketoconazole, fluconazole, buconazole, and miconazole; as monotherapy, boric acid was studied in 7 studies. The mycologic cure rates varied from 40% to 100% in patients treated with boric acid; 4 of the 9 included case series reported statistically significant outcomes regarding cure (both mycologic and clinical) rates. None of the included studies reported statistically significant differences in recurrence rates. Regarding the adverse effects caused by boric acid use, vaginal burning sensation (<10% of cases), water discharge during treatment, and vaginal erythema were identified in 7 studies. Our findings suggest that boric acid is a safe, alternative, economic option for women with recurrent and chronic symptoms of vaginitis when conventional treatment fails because of the involvement of non-albicans Candida spp. or azole-resistant strains.

Vicilin-like peptides from Capsicum baccatum L. seeds are α-amylase inhibitors and exhibit antifungal activity against important yeasts in medical mycology.

PubMed

Vieira Bard, Gabriela C; Nascimento, Viviane V; Oliveira, Antônia Elenir A; Rodrigues, Rosana; Da Cunha, Maura; Dias, Germana B; Vasconcelos, Ilka M; Carvalho, Andre O; Gomes, Valdirene M

2014-07-01

The objective of this study was to isolate antimicrobial peptides from Capsicum baccatum seeds and evaluate their antimicrobial activity and inhibitory effects against α-amylase. Initially, proteins from the flour of C. baccatum seeds were extracted in sodium phosphate buffer, pH 5.4, and precipitated with ammonium sulfate at 90% saturation. The D1 and D2 fractions were subjected to antifungal tests against the yeasts Saccharomyces cerevisiae, Candida albicans, Candida tropicalis, and Kluyveromyces marxiannus, and tested against α-amylases from Callosobruchus maculates and human saliva. The D2 fraction presented higher antimicrobial activity and was subjected to further purification and seven new different fractions (H1-H7) were obtained. Peptides in the H4 fraction were sequenced and the N-terminal sequences revealed homology with previously reported storage vicilins from seeds. The H4 fraction exhibited strong antifungal activity and also promoted morphological changes in yeast, including pseudohyphae formation. All fractions, including H4, inhibited mammalian α-amylase activity but only the H4 fraction was able to inhibit C. maculatus α-amylase activity. These results suggest that the fractions isolated from the seeds of C. baccatum can act directly in plant defenses against pathogens and insects. © 2014 Wiley Periodicals, Inc.

Microbial Diversity and Putative Opportunistic Pathogens in Dishwasher Biofilm Communities

PubMed Central

2018-01-01

ABSTRACT Extreme habitats are not only limited to natural environments, but also exist in manmade systems, for instance, household appliances such as dishwashers. Limiting factors, such as high temperatures, high and low pHs, high NaCl concentrations, presence of detergents, and shear force from water during washing cycles, define microbial survival in this extreme system. Fungal and bacterial diversity in biofilms isolated from rubber seals of 24 different household dishwashers was investigated using next-generation sequencing. Bacterial genera such as Pseudomonas, Escherichia, and Acinetobacter, known to include opportunistic pathogens, were represented in most samples. The most frequently encountered fungal genera in these samples belonged to Candida, Cryptococcus, and Rhodotorula, also known to include opportunistic pathogenic representatives. This study showed how specific conditions of the dishwashers impact the abundance of microbial groups and investigated the interkingdom and intrakingdom interactions that shape these biofilms. The age, usage frequency, and hardness of incoming tap water of dishwashers had significant impact on bacterial and fungal community compositions. Representatives of Candida spp. were found at the highest prevalence (100%) in all dishwashers and are assumed to be one of the first colonizers in recently purchased dishwashers. Pairwise correlations in tested microbiomes showed that certain bacterial groups cooccur, as did the fungal groups. In mixed bacterial-fungal biofilms, early adhesion, contact, and interactions were vital in the process of biofilm formation, where mixed complexes of bacteria and fungi could provide a preliminary biogenic structure for the establishment of these biofilms. IMPORTANCE Worldwide demand for household appliances, such as dishwashers and washing machines, is increasing, as is the number of immunocompromised individuals. The harsh conditions in household dishwashers should prevent the growth of most microorganisms. However, our research shows that persisting polyextremotolerant groups of microorganisms in household appliances are well established under these unfavorable conditions and supported by the biofilm mode of growth. The significance of our research is in identifying the microbial composition of biofilms formed on dishwasher rubber seals, how diverse abiotic conditions affect microbiota, and which key microbial members were represented in early colonization and contamination of dishwashers, as these appliances can present a source of domestic cross-contamination that leads to broader medical impacts. PMID:29330184

Small but Crucial: The Novel Small Heat Shock Protein Hsp21 Mediates Stress Adaptation and Virulence in Candida albicans

PubMed Central

Mayer, François L.; Wilson, Duncan; Jacobsen, Ilse D.; Miramón, Pedro; Slesiona, Silvia; Bohovych, Iryna M.; Brown, Alistair J. P.; Hube, Bernhard

2012-01-01

Small heat shock proteins (sHsps) have multiple cellular functions. However, the biological function of sHsps in pathogenic microorganisms is largely unknown. In the present study we identified and characterized the novel sHsp Hsp21 of the human fungal pathogen Candida albicans. Using a reverse genetics approach we demonstrate the importance of Hsp21 for resistance of C. albicans to specific stresses, including thermal and oxidative stress. Furthermore, a hsp21Δ/Δ mutant was defective in invasive growth and formed significantly shorter filaments compared to the wild type under various filament-inducing conditions. Although adhesion to and invasion into human-derived endothelial and oral epithelial cells was unaltered, the hsp21Δ/Δ mutant exhibited a strongly reduced capacity to damage both cell lines. Furthermore, Hsp21 was required for resisting killing by human neutrophils. Measurements of intracellular levels of stress protective molecules demonstrated that Hsp21 is involved in both glycerol and glycogen regulation and plays a major role in trehalose homeostasis in response to elevated temperatures. Mutants defective in trehalose and, to a lesser extent, glycerol synthesis phenocopied HSP21 deletion in terms of increased susceptibility to environmental stress, strongly impaired capacity to damage epithelial cells and increased sensitivity to the killing activities of human primary neutrophils. Via systematic analysis of the three main C. albicans stress-responsive kinases (Mkc1, Cek1, Hog1) under a range of stressors, we demonstrate Hsp21-dependent phosphorylation of Cek1 in response to elevated temperatures. Finally, the hsp21Δ/Δ mutant displayed strongly attenuated virulence in two in vivo infection models. Taken together, Hsp21 mediates adaptation to specific stresses via fine-tuning homeostasis of compatible solutes and activation of the Cek1 pathway, and is crucial for multiple stages of C. albicans pathogenicity. Hsp21 therefore represents the first reported example of a small heat shock protein functioning as a virulence factor in a eukaryotic pathogen. PMID:22685587

Systemic and mucosal immunization with Candida albicans hsp90 elicits hsp90-specific humoral response in vaginal mucosa which is further enhanced during experimental vaginal candidiasis.

PubMed

Raska, Milan; Belakova, Jana; Horynova, Milada; Krupka, Michal; Novotny, Jiri; Sebestova, Martina; Weigl, Evzen

2008-08-01

The Candida albicans heat shock protein 90 kDa (hsp90-CA) is an important target for protective antibodies in disseminated candidiasis of experimental mice and humans. Hsp90-CA is present in the cell wall of Candida pseudohyphae or hyphae--typical pathogenic morphotypes in both mucosal and systemic Candida infections. However, the potential protective effects of hsp90-CA-specific antibodies in vaginal candidiasis has not yet been reported. In the present study we used various vaccine formulations (recombinant hsp90-CA protein and hsp90-CA-encoding DNA vaccine) and routes of administration (intradermal, intranasal, and intravenous) to induce both hsp90-CA-specific systemic and vaginal mucosa immune responses in experimental BALB/c mice. The results showed that intradermal recombinant hsp90-CA protein priming, followed by intranasal or intradermal recombinant hsp90-CA protein boosting induced significant increases in both serum and vaginal hsp90-CA-specific IgG and IgA antibodies compared to the control group, as well as enhanced hsp90-CA-specific splenocyte responses in vitro. In the intradermally boosted group, subsequent experimental vaginal Candida infection induced additional increases in the hsp90-CA specific IgG isotype, suggesting that Candida has the ability to induce a local hsp90-specific antibody (IgG) response during vulvovaginal candidiasis. Further work is required to elucidate the importance of immunity to highly conserved antigens during infection of the human female reproductive tract where a balance between immunity to and tolerance for commonly antigens such as hsp90 is necessary for the maintenance of fertility.

Biosynthesis of micro- and nanocrystals of Pb (II), Hg (II) and Cd (II) sulfides in four Candida species: a comparative study of in vivo and in vitro approaches.

PubMed

Cuéllar-Cruz, Mayra; Lucio-Hernández, Daniela; Martínez-Ángeles, Isabel; Demitri, Nicola; Polentarutti, Maurizio; Rosales-Hoz, María J; Moreno, Abel

2017-03-01

Nature produces biominerals (biogenic minerals) that are synthesized as complex structures, in terms of their physicochemical properties. These biominerals are composed of minerals and biological macromolecules. They are produced by living organisms and are usually formed through a combination of chemical, biochemical and biophysical processes. Microorganisms like Candida in the presence of heavy metals can biomineralize those metals to form microcrystals (MCs) and nanocrystals (NCs). In this work, MCs and NCs of PbS, HgS or HgCl 2 as well as CdS are synthesized both in vitro (gels) and in vivo by four Candida species. Our in vivo results show that, in the presence of Pb 2+ , Candida cells are able to replicate and form extracellular PbS MCs, whereas in the presence of Hg 2+ and Cd 2+ , they did synthesize intercellular MCs from HgS or HgCl 2 and CdS NCs respectively. The MCs and NCs biologically obtained in Candida were compared with those PbS, HgS and CdS crystals synthetically obtained in vitro through the gel method (grown either in agarose or in sodium metasilicate hydrogels). This is, to our knowledge, the first time that the biosynthesis of the various MCs and NCs (presented in several species of Candida) has been reported. This biosynthesis is differentially regulated in each of these pathogens, which allows them to adapt and survive in different physiological and environmental habitats. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

The Elusive Anti-Candida Vaccine: Lessons From the Past and Opportunities for the Future

PubMed Central

Tso, Gloria Hoi Wan; Reales-Calderon, Jose Antonio; Pavelka, Norman

2018-01-01

Candidemia is a bloodstream fungal infection caused by Candida species and is most commonly observed in hospitalized patients. Even with proper antifungal drug treatment, mortality rates remain high at 40–50%. Therefore, prophylactic or preemptive antifungal medications are currently recommended in order to prevent infections in high-risk patients. Moreover, the majority of women experience at least one episode of vulvovaginal candidiasis (VVC) throughout their lifetime and many of them suffer from recurrent VVC (RVVC) with frequent relapses for the rest of their lives. While there currently exists no definitive cure, the only available treatment for RVVC is again represented by antifungal drug therapy. However, due to the limited number of existing antifungal drugs, their associated side effects and the increasing occurrence of drug resistance, other approaches are greatly needed. An obvious prevention measure for candidemia or RVVC relapse would be to immunize at-risk patients with a vaccine effective against Candida infections. In spite of the advanced and proven techniques successfully applied to the development of antibacterial or antiviral vaccines, however, no antifungal vaccine is still available on the market. In this review, we first summarize various efforts to date in the development of anti-Candida vaccines, highlighting advantages and disadvantages of each strategy. We next unfold and discuss general hurdles encountered along these efforts, such as the existence of large genomic variation and phenotypic plasticity across Candida strains and species, and the difficulty in mounting protective immune responses in immunocompromised or immunosuppressed patients. Lastly, we review the concept of “trained immunity” and discuss how induction of this rapid and nonspecific immune response may potentially open new and alternative preventive strategies against opportunistic infections by Candida species and potentially other pathogens. PMID:29755472

Oral Candida colonization in oral cancer patients and its relationship with traditional risk factors of oral cancer: a matched case-control study.

PubMed

Alnuaimi, Ali D; Wiesenfeld, David; O'Brien-Simpson, Neil M; Reynolds, Eric C; McCullough, Michael J

2015-02-01

Candida, an opportunistic fungal pathogen, has been implicated in oral and oesophageal cancers. This study aimed to examine oral Candida carriage in 52 oral cancer patients and 104 age-, gender- and denture status-matched oral cancer-free subjects. We assessed general health, smoking and alcohol drinking habits, use of alcohol-containing mouthwash and periodontal status (community periodontal index of treatment needs). Yeasts were isolated using oral rinse technique and genetically identified via Real-Time PCR-High resolution melting curve analysis of conserved ribosomal DNA. Conditional and binary logistic regressions were used to identify explanatory variables that are risk factors for oral cancer. The frequencies of oral yeasts' presence and high oral colonization were significantly higher in oral cancer than non-oral cancer patients (p=001; p=0.033, respectively). No significant difference in the isolation profile of Candida species was found between the two groups, except C. parapsilosis was more frequent in non-oral cancer group. Differences were noticed in the incidence of C. albicans strains where significantly more C. albicans genotype-A was isolated from cancer patients and significantly more C. albicans genotype-B isolated from non-cancer patients. Multiple regression analyses showed significant association with cancer observed for alcohol drinking (OR=4.253; 95% CI=1.351, 13.386), Candida presence (OR=3.242; 95% CI=1.505, 6.984) and high oral colonization (OR=3.587; 95% CI=1.153, 11.162). These results indicate that there is a significant association between oral cancer occurrence and Candida oral colonization and that the observed genotypic diversity of C. albicans strains may play a role in oral carcinogenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

First report of Candida auris in America: Clinical and microbiological aspects of 18 episodes of candidemia.

PubMed

Calvo, Belinda; Melo, Analy S A; Perozo-Mena, Armindo; Hernandez, Martin; Francisco, Elaine Cristina; Hagen, Ferry; Meis, Jacques F; Colombo, Arnaldo Lopes

2016-10-01

Characterization of a hospital outbreak of Candida auris candidemia that involved 18 critically ill patients in Venezuela. Bloodstream isolates of C. auris obtained from 18 patients admitted at a medical center in Maracaibo, between March, 2012 and July, 2013 were included. Species identification was confirmed by ITS rDNA sequencing. Isolates were subsequently typed by amplified fragment length polymorphism fingerprinting (AFLP). Susceptibility testing was performed according to CLSI. Clinical data were collected from all cases by using a standard clinical form. A total of 13 critically ill pediatric and 5 adult patients, with a median age of 26 days, were included. All were previously exposed to antibiotics and multiple invasive medical procedures. Clinical management included prompt catheter removal and antifungal therapy. Thirteen patients (72%) survived up to 30 days after onset of candidemia. AFLP fingerprinting of all C. auris isolates suggested a clonal outbreak. The isolates were considered resistant to azoles, but susceptible to anidulafungin and 50% of isolates exhibited amphotericin B MIC values of >1 μg/ml. The study demonstrated that C. auris is a multiresistant yeast pathogen that can be a source of health-care associated infections in tertiary care hospitals with a high potential for nosocomial horizontal transmission. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Specific Human and Candida Cellular Interactions Lead to Controlled or Persistent Infection Outcomes during Granuloma-Like Formation.

PubMed

Misme-Aucouturier, Barbara; Albassier, Marjorie; Alvarez-Rueda, Nidia; Le Pape, Patrice

2017-01-01

A delayed type of multicellular process could be crucial during chronic candidiasis in determining the course of infection. This reaction, consisting of organized immune cells surrounding the pathogen, initiates an inflammatory response to avoid fungal dissemination. The goal of the present study was to examine, at an in vitro cellular scale, Candida and human immune cell interaction dynamics during a long-term period. By challenging human peripheral blood immune cells from 10 healthy donors with 32 Candida albicans and non-albicans (C. glabrata, C. tropicalis, C. parapsilosis, C. dubliniensis, C. lusitaniae, C. krusei, and C. kefyr) clinical isolates, we showed that Candida spp. induced the formation of granuloma-like structures within 6 days after challenge, but their sizes and the respective fungal burdens differed according to the Candida species. These two parameters are positively correlated. Phenotypic characteristics, such as hypha formation and higher axenic growth rate, seem to contribute to yeast persistence within granuloma-like structures. We showed an interindividual variability of the human response against Candida spp. Higher proportions of neutrophils and elevated CD4 + /CD8 + T cell ratios during the first days after challenge were correlated with early production of gamma interferon (IFN-γ) and associated with controlled infection. In contrast, the persistence of Candida could result from upregulation of proinflammatory cytokines such as interleukin-6 (IL-6), IFN-γ, and tumor necrosis factor alpha (TNF-α) and a poor anti-inflammatory negative feedback (IL-10). Importantly, regulatory subsets of NK cells and CD4 lo CD8 hi doubly positive (DP) lymphocytes at late stage infiltrate granuloma-like structures and could correlate with the IL-10 and TNF-α production. These data offer a base frame to explain cellular events that guide infection control or fungal persistence. Copyright © 2016 Misme-Aucouturier et al.

Multiple Origins of the Pathogenic Yeast Candida orthopsilosis by Separate Hybridizations between Two Parental Species.

PubMed

Schröder, Markus S; Martinez de San Vicente, Kontxi; Prandini, Tâmara H R; Hammel, Stephen; Higgins, Desmond G; Bagagli, Eduardo; Wolfe, Kenneth H; Butler, Geraldine

2016-11-01

Mating between different species produces hybrids that are usually asexual and stuck as diploids, but can also lead to the formation of new species. Here, we report the genome sequences of 27 isolates of the pathogenic yeast Candida orthopsilosis. We find that most isolates are diploid hybrids, products of mating between two unknown parental species (A and B) that are 5% divergent in sequence. Isolates vary greatly in the extent of homogenization between A and B, making their genomes a mosaic of highly heterozygous regions interspersed with homozygous regions. Separate phylogenetic analyses of SNPs in the A- and B-derived portions of the genome produces almost identical trees of the isolates with four major clades. However, the presence of two mutually exclusive genotype combinations at the mating type locus, and recombinant mitochondrial genomes diagnostic of inter-clade mating, shows that the species C. orthopsilosis does not have a single evolutionary origin but was created at least four times by separate interspecies hybridizations between parents A and B. Older hybrids have lost more heterozygosity. We also identify two isolates with homozygous genomes derived exclusively from parent A, which are pure non-hybrid strains. The parallel emergence of the same hybrid species from multiple independent hybridization events is common in plant evolution, but is much less documented in pathogenic fungi.

Biocontrol activity of four non- and low-fermenting yeast strains against Aspergillus carbonarius and their ability to remove ochratoxin A from grape juice.

PubMed

Fiori, Stefano; Urgeghe, Pietro Paolo; Hammami, Walid; Razzu, Salvatorico; Jaoua, Samir; Migheli, Quirico

2014-10-17

Aspergillus spp. infection of grape may lead to ochratoxin A (OTA) contamination in processed beverages such as wine and grape juice. The aim of the current study was to evaluate the biocontrol potential of two non-fermenting (Cyberlindnera jadinii 273 and Candida friedrichii 778) and two low-fermenting (Candida intermedia 235 and Lachancea thermotolerans 751) yeast strains against the pathogenic fungus and OTA-producer Aspergillus carbonarius, and their ability to remove OTA from grape juice. Two strains, 235 and 751, showed a significant ability to inhibit A. carbonarius both on grape berries and in in vitro experiments. Neither their filtrate nor their autoclaved filtrate culture broth was able to prevent consistently pathogen growth. Volatile organic compounds (VOCs) produced by all four selected yeasts were likely able to consistently prevent pathogen sporulation in vitro. VOCs produced by the non-fermenting strain 778 also significantly reduced A. carbonarius vegetative growth. Three yeast strains (235, 751, and 778) efficiently adsorbed artificially spiked OTA from grape juice, while autoclaving treatment improved OTA adsorption capacity by all the four tested strains. Biological control of A. carbonarius and OTA-decontamination using yeast is proposed as an approach to meet the Islamic dietary laws concerning the absence of alcohol in halal beverages. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Modelling the host-pathogen interactions of macrophages and Candida albicans using Game Theory and dynamic optimization.

PubMed

Dühring, Sybille; Ewald, Jan; Germerodt, Sebastian; Kaleta, Christoph; Dandekar, Thomas; Schuster, Stefan

2017-07-01

The release of fungal cells following macrophage phagocytosis, called non-lytic expulsion, is reported for several fungal pathogens. On one hand, non-lytic expulsion may benefit the fungus in escaping the microbicidal environment of the phagosome. On the other hand, the macrophage could profit in terms of avoiding its own lysis and being able to undergo proliferation. To analyse the causes of non-lytic expulsion and the relevance of macrophage proliferation in the macrophage- Candida albicans interaction, we employ Evolutionary Game Theory and dynamic optimization in a sequential manner. We establish a game-theoretical model describing the different strategies of the two players after phagocytosis. Depending on the parameter values, we find four different Nash equilibria and determine the influence of the systems state of the host upon the game. As our Nash equilibria are a direct consequence of the model parameterization, we can depict several biological scenarios. A parameter region, where the host response is robust against the fungal infection, is determined. We further apply dynamic optimization to analyse whether macrophage mitosis is relevant in the host-pathogen interaction of macrophages and C. albicans For this, we study the population dynamics of the macrophage- C. albicans interactions and the corresponding optimal controls for the macrophages, indicating the best macrophage strategy of switching from proliferation to attacking fungal cells. © 2017 The Author(s).

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.

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

Denture plaque--past and recent concerns.

PubMed

Nikawa, H; Hamada, T; Yamamoto, T

1998-05-01

This paper critically reviews the history of denture plaque and identifies some concerns with the presence of Candida in the mouth. This review covers literature sources related to Candida albicans and its relationship to denture plaque. The articles selected for this review are from referred journals and describe C. albicans and its relationship to oral, gastrointestinal and pleuropulmonary infections. The relationship to caries, root caries and periodontal disease is also covered. Denture plaque containing Candida could cause not only oral candidiasis, like oral thrush or denture-induced stomatitis, but also caries, root caries and periodontitis of abutment teeth. However, there is only limited experimental evidence or information available on the cariogenicity of Candida. The continuous swallowing or aspiration of micro-organisms from denture plaque exposes patients, particularly the immunocompromised host or medicated elderly, to the risks of unexpected infections. The term, 'denture plaque' has been used throughout the review. However, the term 'plaque on denture' should be used because the microbial flora and its pathogenicity of denture plaque resembles those of plaque formed on the tooth surface, so called dental plaque. In addition, the term 'denture related stomatitis' would be preferable to 'denture induced stomatitis', since the inflammation of (palatal) mucosa is not induced by the denture, but by wearing the denture or by plaque on the denture.

Calcineurin controls hyphal growth, virulence, and drug tolerance of Candida tropicalis.

PubMed

Chen, Ying-Lien; Yu, Shang-Jie; Huang, Hsin-Yu; Chang, Ya-Lin; Lehman, Virginia N; Silao, Fitz Gerald S; Bigol, Ursela G; Bungay, Alice Alma C; Averette, Anna; Heitman, Joseph

2014-07-01

Candida tropicalis, a species closely related to Candida albicans, is an emerging fungal pathogen associated with high mortality rates of 40 to 70%. Like C. albicans and Candida dubliniensis, C. tropicalis is able to form germ tubes, pseudohyphae, and hyphae, but the genes involved in hyphal growth machinery and virulence remain unclear in C. tropicalis. Recently, echinocandin- and azole-resistant C. tropicalis isolates have frequently been isolated from various patients around the world, making treatment difficult. However, studies of the C. tropicalis genes involved in drug tolerance are limited. Here, we investigated the roles of calcineurin and its potential target, Crz1, for core stress responses and pathogenesis in C. tropicalis. We demonstrate that calcineurin and Crz1 are required for hyphal growth, micafungin tolerance, and virulence in a murine systemic infection model, while calcineurin but not Crz1 is essential for tolerance of azoles, caspofungin, anidulafungin, and cell wall-perturbing agents, suggesting that calcineurin has both Crz1-dependent and -independent functions in C. tropicalis. In addition, we found that calcineurin and Crz1 have opposite roles in controlling calcium tolerance. Calcineurin serves as a negative regulator, while Crz1 plays a positive role for calcium tolerance in C. tropicalis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Anti-Candida and anti-Cryptococcus antifungal produced by marine microorganisms.

PubMed

El Amraoui, B; El Amraoui, M; Cohen, N; Fassouane, A

2014-12-01

In order to search for antifungal from biological origin, we performed a screening of marine microorganisms isolated from seawater, seaweed, sediment and marine invertebrates collected from different coastal areas of the Moroccan Atlantic Ocean. The antifungal activities of these isolates were investigated against the pathogenic yeasts involved in medical mycology. Whole cultures of 34 marine microorganisms were screened for antifungal activities using the method of agar diffusion against four yeasts. The results showed that among the 34 isolates studied, 13 (38%) strains have antifungal activity against at least one out of four yeast species, 11 isolates have anti-Candida albicans CIP 48.72 activity, 12 isolates have anti-C. albicans CIP 884.65 activity, 13 isolates have anti-Cryptococcus neoformans activity and only 6 isolates are actives against Candida tropicalis R2 resistant to nystatin and amphotericin B. Nine isolates showed strong fungicidal activity. Fourteen microorganisms were identified and assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea, and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms could produce more antimicrobials; therefore these marine microorganisms were expected to be potential resources of natural products such as those we research: anti-Candida and anti-Cryptococcus fungicides. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Tramadol, an Opioid Receptor Agonist: An Inhibitor of Growth, Morphogenesis, and Biofilm Formation in the Human Pathogen, Candida albicans.

PubMed

Kathwate, Gunderao Hanumantrao; Karuppayil, S Mohan

2016-12-01

Tramadol is a synthetic, centrally acting low-affinity agonist of μ-opioid receptors in humans. It is used as an analgesic and is shown to have local anesthetic action. In this study, we have tried to explore its anti-Candida potential. Minimum inhibitory concentration (MIC50) and minimum fungicidal concentration (MFC) values were established. MIC50 ranged from 2 to 4 mg/mL, whereas MFC was recorded at 8 mg/mL. Also, the effect of tramadol on germ tube formation, adhesion, and biofilms in Candida albicans was studied. Tramadol impaired in vitro growth of C. albicans. A time-dependent killing assay showed that it kills C. albicans within 24 h of exposure. Tramadol has strong activity against Candida virulence factors such as yeast-to-hyphal form switching and adhesion. C. albicans biofilms, which are notoriously resistant to many antifungals, were sensitive to tramadol. At 8 mg/mL of tramadol, 82% of early stage biofilms and 52.88% of matured biofilms were inhibited. Although our results show that the antifungal effect of tramadol requires concentrations that can be achieved only locally, they may provide potential candidates for development of novel antifungal drugs.

Gaining Insights from Candida Biofilm Heterogeneity: One Size Does Not Fit All

PubMed Central

Kean, Ryan; Delaney, Christopher; Rajendran, Ranjith; Sherry, Leighann; Metcalfe, Rebecca; Thomas, Rachael; McLean, William; Williams, Craig; Ramage, Gordon

2018-01-01

Despite their clinical significance and substantial human health burden, fungal infections remain relatively under-appreciated. The widespread overuse of antibiotics and the increasing requirement for indwelling medical devices provides an opportunistic potential for the overgrowth and colonization of pathogenic Candida species on both biological and inert substrates. Indeed, it is now widely recognized that biofilms are a highly important part of their virulence repertoire. Candida albicans is regarded as the primary fungal biofilm forming species, yet there is also increasing interest and growing body of evidence for non-Candida albicans species (NCAS) biofilms, and interkingdom biofilm interactions. C. albicans biofilms are heterogeneous structures by definition, existing as three-dimensional populations of yeast, pseudo-hyphae, and hyphae, embedded within a self-produced extracellular matrix. Classical molecular approaches, driven by extensive studies of laboratory strains and mutants, have enhanced our knowledge and understanding of how these complex communities develop, thrive, and cause host-mediated damage. Yet our clinical observations tell a different story, with differential patient responses potentially due to inherent biological heterogeneity from specific clinical isolates associated with their infections. This review explores some of the recent advances made in an attempt to explore the importance of working with clinical isolates, and what this has taught us. PMID:29371505

GSL-enriched membrane microdomains in innate immune responses.

PubMed

Nakayama, Hitoshi; Ogawa, Hideoki; Takamori, Kenji; Iwabuchi, Kazuhisa

2013-06-01

Many pathogens target glycosphingolipids (GSLs), which, together with cholesterol, GPI-anchored proteins, and various signaling molecules, cluster on host cell membranes to form GSL-enriched membrane microdomains (lipid rafts). These GSL-enriched membrane microdomains may therefore be involved in host-pathogen interactions. Innate immune responses are triggered by the association of pathogens with phagocytes, such as neutrophils, macrophages and dendritic cells. Phagocytes express a diverse array of pattern-recognition receptors (PRRs), which sense invading microorganisms and trigger pathogen-specific signaling. PRRs can recognize highly conserved pathogen-associated molecular patterns expressed on microorganisms. The GSL lactosylceramide (LacCer, CDw17), which binds to various microorganisms, including Candida albicans, is expressed predominantly on the plasma membranes of human mature neutrophils and forms membrane microdomains together with the Src family tyrosine kinase Lyn. These LacCer-enriched membrane microdomains can mediate superoxide generation, migration, and phagocytosis, indicating that LacCer functions as a PRR in innate immunity. Moreover, the interactions of GSL-enriched membrane microdomains with membrane proteins, such as growth factor receptors, are important in mediating the physiological properties of these proteins. Similarly, we recently found that interactions between LacCer-enriched membrane microdomains and CD11b/CD18 (Mac-1, CR3, or αMβ2-integrin) are significant for neutrophil phagocytosis of non-opsonized microorganisms. This review describes the functional role of LacCer-enriched membrane microdomains and their interactions with CD11b/CD18.

Antibiofilm activity of carboxymethyl chitosan on the biofilms of non-Candida albicans Candida species.

PubMed

Tan, Yulong; Leonhard, Matthias; Moser, Doris; Schneider-Stickler, Berit

2016-09-20

Although most cases of candidiasis have been attributed to Candida albicans, non-C. albicans Candida species have been isolated in increasing numbers in patients. In this study, we determined the inhibition of carboxymethyl chitosan (CM-chitosan) on single and mixed species biofilm of non-albicans Candida species, including Candida tropicalis, Candida parapsilosis, Candida krusei and Candida glabrata. Biofilm by all tested species in microtiter plates were inhibited nearly 70%. CM-chitosan inhibited mixed species biofilm in microtiter plates and also on medical materials surfaces. To investigate the mechanism, the effect of CM-chitosan on cell viability and biofilm growth was employed. CM-chitosan inhibited Candida planktonic growth as well as adhesion. Further biofilm formation was inhibited with CM-chitosan added at 90min, 12h or 24h after biofilm initiation. CM-chitosan was not only able to inhibit the metabolic activity of Candida cells, but was also active upon the establishment and the development of biofilms. Copyright © 2016 Elsevier Ltd. All rights reserved.

The antibiotic polymyxin B exhibits novel antifungal activity against Fusarium species.

PubMed

Hsu, Li-Hang; Wang, Hsuan-Fu; Sun, Pei-Lun; Hu, Fung-Rong; Chen, Ying-Lien

2017-06-01

The genus Fusarium comprises many species, including Fusarium oxysporum, Fusarium solani, Fusarium graminearum and Fusarium verticillioides, and causes severe infections in plants and humans. In clinical settings, Fusarium is the third most frequent mould to cause invasive fungal infections after Aspergillus and the Mucorales. F. solani and F. oxysporum are the most prevalent Fusarium spp. causing clinical disease. However, few effective antifungal drugs are available to treat human and plant Fusarium infections. The cationic peptide antibiotic polymyxin B (PMB) exhibits antifungal activity against the human fungal pathogens Candida albicans and Cryptococcus neoformans, but its efficacy against Fusarium spp. is unknown. In this study, the antifungal activity of PMB was tested against 12 Fusarium strains that infect humans and plants (banana, tomato, melon, pea, wheat and maize). PMB was fungicidal against all 12 Fusarium strains, with minimum fungicidal concentrations of 32 µg/mL or 64 µg/mL for most strains tested, as evidenced by broth dilution, methylene blue staining and XTT reduction assays. PMB can reduce the germination rates of conidia, but not chlamydospores, and can cause defects in cell membrane integrity in Fusarium strains. PMB exhibits synergistic activity with posaconazole and can potentiate the effect of fluconazole, voriconazole or amphotericin B against Fusarium spp. However, PMB does not show synergistic effects with fluconazole against Fusarium spp. as it does against Candida glabrata and C. neoformans, indicating evolutionary divergence of mechanisms between yeast pathogens and the filamentous fungus Fusarium. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Developmental Regulation of an Adhesin Gene during Cellular Morphogenesis in the Fungal Pathogen Candida albicans▿ †

PubMed Central

Argimón, Silvia; Wishart, Jill A.; Leng, Roger; Macaskill, Susan; Mavor, Abigail; Alexandris, Thomas; Nicholls, Susan; Knight, Andrew W.; Enjalbert, Brice; Walmsley, Richard; Odds, Frank C.; Gow, Neil A. R.; Brown, Alistair J. P.

2007-01-01

Candida albicans expresses specific virulence traits that promote disease establishment and progression. These traits include morphological transitions between yeast and hyphal growth forms that are thought to contribute to dissemination and invasion and cell surface adhesins that promote attachment to the host. Here, we describe the regulation of the adhesin gene ALS3, which is expressed specifically during hyphal development in C. albicans. Using a combination of reporter constructs and regulatory mutants, we show that this regulation is mediated by multiple factors at the transcriptional level. The analysis of ALS3 promoter deletions revealed that this promoter contains two activation regions: one is essential for activation during hyphal development, while the second increases the amplitude of this activation. Further deletion analyses using the Renilla reniformis luciferase reporter delineate the essential activation region between positions −471 and −321 of the promoter. Further 5′ or 3′ deletions block activation. ALS3 transcription is repressed mainly by Nrg1 and Tup1, but Rfg1 contributes to this repression. Efg1, Tec1, and Bcr1 are essential for the transcriptional activation of ALS3, with Tec1 mediating its effects indirectly through Bcr1 rather than through the putative Tec1 sites in the ALS3 promoter. ALS3 transcription is not affected by Cph2, but Cph1 contributes to full ALS3 activation. The data suggest that multiple morphogenetic signaling pathways operate through the promoter of this adhesin gene to mediate its developmental regulation in this major fungal pathogen. PMID:17277173

Biotin protein ligase from Candida albicans: expression, purification and development of a novel assay.

PubMed

Pendini, Nicole R; Bailey, Lisa M; Booker, Grant W; Wilce, Matthew C J; Wallace, John C; Polyak, Steven W

2008-11-15

Biotin protein ligase (BPL) is an essential enzyme responsible for the activation of biotin-dependent enzymes through the covalent attachment of biotin. In yeast, disruption of BPL affects important metabolic pathways such as fatty acid biosynthesis and gluconeogenesis. This makes BPL an attractive drug target for new antifungal agents. Here we report the cloning, recombinant expression and purification of BPL from the fungal pathogen Candida albicans. The biotin domains of acetyl CoA carboxylase and pyruvate carboxylase were also cloned and characterised as substrates for BPL. A novel assay was established thereby allowing examination of the enzyme's properties. These findings will facilitate future structural studies as well as screening efforts to identify potential inhibitors.

Phospholipid biosynthesis in Candida albicans: Regulation by the precursors inositol and choline

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

Klig, L.S.; Friedli, L.; Schmid, E.

1990-08-01

Phospholipid metabolism in the pathogenic fungus Candida albicans was examined. The phospholipid biosynthetic pathways of C. albicans were elucidated and were shown to be similar to those of Saccharomyces cerevisiae. However, marked differences were seen between these two fungi in the regulation of the pathways in response to exogenously provided precursors inositol and choline. In S. cerevisiae, the biosynthesis of phosphatidylcholine via methylation of phosphatidylethanolamine appears to be regulated in response to inositol and choline; provision of choline alone does not repress the activity of this pathway. The same pathway in C. albicans responds to the exogenous provision of choline.more » Possible explanations for the observed differences in regulation are discussed.« less

Direct impression on agar surface as a diagnostic sampling procedure for candida balanitis.

PubMed

Lisboa, Carmen; Santos, António; Azevedo, Filomena; Pina-Vaz, Cidália; Rodrigues, Acácio Gonçalves

2010-02-01

The diagnosis of candida balanitis should be based upon both clinical and mycological data. The procedure of material collection is a critical issue to confirm or rule out the clinical diagnosis of candida balanitis. To compare direct impression of the glans on the agar surface of solid culture media with the collection of genital exudates with cotton swab for the diagnosis of candida balanitis. A prospective cross-sectional study was carried out during a 36-month period. Sexually transmitted disease clinic attendees with balanitis and asymptomatic men were included. Specimens for yeast culture were collected from the glans penis and inner preputial layer using the direct impression on CHROMagar candida medium and by swabbing with a sterile cotton swab. Among 478 men enrolled, 189 had balanitis. The prevalence of candida balanitis was 17.8% (85/478) confirmed after culture by direct impression; the swab method detected only 54/85 (63.5%) of these men. Of the 289 asymptomatic men, 36 (12.5%) yielded Candida spp; the swab method detected only 38.9% of these men. The risk of having candida balanitis is 8.9 (IC 95% 2.48 to 32.04) whenever the number of candida colonies recovered by direct impression was greater than 10. Direct impression on CHROMagar candida medium resulted in the highest Candida spp recovery rate. More than 10 colonies yielded by impression culture were statistically associated with candida balanitis. This method shows the ideal profile for sampling the male genital area for yeasts and should be included in the management of balanitis.

Bacteremias in liver transplant recipients: shift toward gram-negative bacteria as predominant pathogens.

PubMed

Singh, Nina; Wagener, Marilyn M; Obman, Asia; Cacciarelli, Thomas V; de Vera, Michael E; Gayowski, Timothy

2004-07-01

During the 1990s, gram-positive bacteria emerged as major pathogens after liver transplantation. We sought to determine whether the pathogens associated with bacteremias in liver transplant recipients have changed. Patients included 233 liver transplant recipients transplanted between 1989 and 2003. The proportion of all infections due to bacteremias increased significantly over time (P <.0001). Of other major infections, a trend toward a decrease in fungal infections (P =.089) and a significant decrease in cytomegalovirus (CMV) disease (P =.0004) were documented. Whereas the proportion of bacteremias due to gram-negatives increased from 25% in the period of 1989-1993 to 51.8% in 1998-03, that of gram-positive bacteria decreased from 75% in the period of 1989-93 to 48.2% in the period of 1998-2003. Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most frequent pathogens in bacteremic patients. The incidence of bacteremias due to MRSA and Pseudomonas aeruginosa has remained unchanged (P <.20); however, that due to enteric gram-negative bacteria, particularly Klebsiella pneumoniae has increased (P =.02). Klebsiella pneumoniae isolates in the current quartile were not clonally related. In conclusion, bacteremias as a proportion of all infections in liver transplant recipients have increased significantly over time, due in part to a decline in infections due to other major pathogens, e.g., fungi, primarily Candida species, and CMV. Gram-negative bacteria have emerged as predominant pathogens in bacteremic liver transplant recipients.

Antibiosis of vineyard ecosystem fungi against food-borne microorganisms.

PubMed

Cueva, Carolina; Moreno-Arribas, M Victoria; Bartolomé, Begoña; Salazar, Óscar; Vicente, M Francisca; Bills, Gerald F

2011-12-01

Fermentation extracts from fungi isolated from vineyard ecosystems were tested for antimicrobial activities against a set of test microorganisms, including five food-borne pathogens (Staphylococcus aureus EP167, Acinetobacter baumannii (clinically isolated), Pseudomonas aeruginosa PAO1, Escherichia coli O157:H7 (CECT 5947) and Candida albicans MY1055) and two probiotic bacteria (Lactobacillus plantarum LCH17 and Lactobacillus brevis LCH23). A total of 182 fungi was grown in eight different media, and the fermentation extracts were screened for antimicrobial activity. A total of 71 fungi produced extracts active against at least one pathogenic microorganism, but not against any probiotic bacteria. The Gram-positive bacterium S. aureus EP167 was more susceptible to antimicrobial fungi broth extracts than Gram-negative bacteria and pathogenic fungi. Identification of active fungi based on internal transcribed spacer rRNA sequence analysis revealed that species in the orders Pleosporales, Hypocreales and Xylariales dominated. Differences in antimicrobial selectivity were observed among isolates from the same species. Some compounds present in the active extracts were tentatively identified by liquid chromatography-mass spectrometry. Antimicrobial metabolites produced by vineyard ecosystem fungi may potentially limit colonization and spoilage of food products by food-borne pathogens, with minimal effect on probiotic bacteria. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Genome Sequence of the Yeast Clavispora lusitaniae Type Strain CBS 6936.

PubMed

Durrens, Pascal; Klopp, Christophe; Biteau, Nicolas; Fitton-Ouhabi, Valérie; Dementhon, Karine; Accoceberry, Isabelle; Sherman, David J; Noël, Thierry

2017-08-03

Clavispora lusitaniae , an environmental saprophytic yeast belonging to the CTG clade of Candida , can behave occasionally as an opportunistic pathogen in humans. We report here the genome sequence of the type strain CBS 6936. Comparison with sequences of strain ATCC 42720 indicates conservation of chromosomal structure but significant nucleotide divergence. Copyright © 2017 Durrens et al.

Genome Sequence of the Yeast Clavispora lusitaniae Type Strain CBS 6936

PubMed Central

Klopp, Christophe; Biteau, Nicolas; Fitton-Ouhabi, Valérie; Dementhon, Karine; Accoceberry, Isabelle; Sherman, David J.; Noël, Thierry

2017-01-01

ABSTRACT Clavispora lusitaniae, an environmental saprophytic yeast belonging to the CTG clade of Candida, can behave occasionally as an opportunistic pathogen in humans. We report here the genome sequence of the type strain CBS 6936. Comparison with sequences of strain ATCC 42720 indicates conservation of chromosomal structure but significant nucleotide divergence. PMID:28774979

Metabolism in Fungal Pathogenesis

PubMed Central

Ene, Iuliana V.; Brunke, Sascha; Brown, Alistair J.P.; Hube, Bernhard

2014-01-01

Fungal pathogens must assimilate local nutrients to establish an infection in their mammalian host. We focus on carbon, nitrogen, and micronutrient assimilation mechanisms, discussing how these influence host–fungus interactions during infection. We highlight several emerging trends based on the available data. First, the perturbation of carbon, nitrogen, or micronutrient assimilation attenuates fungal pathogenicity. Second, the contrasting evolutionary pressures exerted on facultative versus obligatory pathogens have led to contemporary pathogenic fungal species that display differing degrees of metabolic flexibility. The evolutionarily ancient metabolic pathways are conserved in most fungal pathogen, but interesting gaps exist in some species (e.g., Candida glabrata). Third, metabolic flexibility is generally essential for fungal pathogenicity, and in particular, for the adaptation to contrasting host microenvironments such as the gastrointestinal tract, mucosal surfaces, bloodstream, and internal organs. Fourth, this metabolic flexibility relies on complex regulatory networks, some of which are conserved across lineages, whereas others have undergone significant evolutionary rewiring. Fifth, metabolic adaptation affects fungal susceptibility to antifungal drugs and also presents exciting opportunities for the development of novel therapies. PMID:25190251

Calcineurin Controls Drug Tolerance, Hyphal Growth, and Virulence in Candida dubliniensis▿†

PubMed Central

Chen, Ying-Lien; Brand, Alexandra; Morrison, Emma L.; Silao, Fitz Gerald S.; Bigol, Ursela G.; Malbas, Fedelino F.; Nett, Jeniel E.; Andes, David R.; Solis, Norma V.; Filler, Scott G.; Averette, Anna; Heitman, Joseph

2011-01-01

Candida dubliniensis is an emerging pathogenic yeast species closely related to Candida albicans and frequently found colonizing or infecting the oral cavities of HIV/AIDS patients. Drug resistance during C. dubliniensis infection is common and constitutes a significant therapeutic challenge. The calcineurin inhibitor FK506 exhibits synergistic fungicidal activity with azoles or echinocandins in the fungal pathogens C. albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In this study, we show that calcineurin is required for cell wall integrity and wild-type tolerance of C. dubliniensis to azoles and echinocandins; hence, these drugs are candidates for combination therapy with calcineurin inhibitors. In contrast to C. albicans, in which the roles of calcineurin and Crz1 in hyphal growth are unclear, here we show that calcineurin and Crz1 play a clearly demonstrable role in hyphal growth in response to nutrient limitation in C. dubliniensis. We further demonstrate that thigmotropism is controlled by Crz1, but not calcineurin, in C. dubliniensis. Similar to C. albicans, C. dubliniensis calcineurin enhances survival in serum. C. dubliniensis calcineurin and crz1/crz1 mutants exhibit attenuated virulence in a murine systemic infection model, likely attributable to defects in cell wall integrity, hyphal growth, and serum survival. Furthermore, we show that C. dubliniensis calcineurin mutants are unable to establish murine ocular infection or form biofilms in a rat denture model. That calcineurin is required for drug tolerance and virulence makes fungus-specific calcineurin inhibitors attractive candidates for combination therapy with azoles or echinocandins against emerging C. dubliniensis infections. PMID:21531874

Vulvovaginitis in prepubertal girls

PubMed Central

Stricker, T; Navratil, F; Sennhauser, F

2003-01-01

This retrospective study evaluated the clinical features and findings in bacterial cultures and in microscopic examination of vaginal secretions in 80 prepubertal girls, aged 2–12 years, with vulvovaginitis. Vaginal secretions were obtained directly from the vagina with a sterile catheter carefully inserted into the vagina. Pathogenic bacteria were isolated in 36% of cases. In 59% of these cases the isolated pathogen was group A ß-haemolytic streptococcus. Candida was not found in any of the patients. The finding of leucocytes in vaginal secretions as an indicator for growth of pathogenic bacteria had a sensitivity of 83% and a specificity of 59%. Antimicrobial treatment should therefore be based on bacteriological findings of vaginal secretions and not on the presence of leucocytes alone. PMID:12651758

Simultaneous detection of multiple lower genital tract pathogens by an impedimetric immunochip.

PubMed

Chiriacò, Maria Serena; Primiceri, Elisabetta; De Feo, Francesco; Montanaro, Alessandro; Monteduro, Anna Grazia; Tinelli, Andrea; Megha, Marcella; Carati, Davide; Maruccio, Giuseppe

2016-05-15

Lower genital tract infections caused by both sexually and not-sexually transmitted pathogens in women are a key public health priority worldwide, especially in developing countries. Since standard analyses are time-consuming, appropriate therapeutic intervention is often neglected or delayed. Lab-on-chips and biosensors open new perspectives and offer innovative tools to simplify the diagnosis by medical staff, especially in countries with inadequate resources. Here we report a biosensing platform based on Electrochemical Impedance Spectroscopy (EIS) that allows multiplexed detection of Candida albicans, Streptococcus agalactiae and Chlamydia trachomatis with a single biochip, enabling a quick screening thanks to the presence of different immobilized antibodies, each specific for one of the different target pathogens. Copyright © 2015 Elsevier B.V. All rights reserved.

Sexually transmitted pathogens in pregnant women in a rural South African community.

PubMed Central

O'Farrell, N; Hoosen, A A; Kharsany, A B; van den Ende, J

1989-01-01

One hundred and ninety three consecutive pregnant women attending peripheral antenatal clinics attached to Ngwelezana Hospital, Empangeni, Kwa-Zulu, were examined for evidence of sexually transmitted pathogens. The following incidences were found: Trichomonas vaginalis 49.2% (95), Candida spp 38.3% (74), Chlamydia trachomatis 11.4% (22), Gardnerella vaginalis 6.2% (12), Neisseria gonorrhoeae 5.7% (11), positive syphilis serology results 11.9% (23), hepatitis B surface antigen 4.1% (eight). No woman had antibody to human immunodeficiency virus (HIV). Dyskaryotic smears were found in 20 (10.4%). Human papillomavirus (HPV) was detected cytologically in 11 (5.7%). The range of sexually transmitted pathogens found in this rural community was similar to that found in urban groups studied in South Africa. PMID:2807289

[Analysis of characteristics of bacteria in respiratory tract infection in 2013-2016 in Heibei 3A hospital: a single-center report of 7 497 patients].

PubMed

Hou, Lili; Liu, Lili; Dang, Ping; Kang, Guannan; Zhang, Qinfeng; Li, Dongling

2017-09-01

To analyze the changes and characteristics of respiratory tract bacteria in Hebei 3A Hospital, and to provide new rationale for clinical diagnosis and treatment. A single-center retrospective analysis was conducted. 7 497 patients with respiratory tract infection admitted to Hebei Chest Hospital from January 2013 to December 2016 were enrolled. Deep sputum was collected, and the bacterial cultures and susceptibility analysis was conducted in sputum and upper respiratory secretions were collected by fiberoptic bronchoscopy. A total of 7 497 patients with respiratory tract infection were enrolled in the study, and 11 909 strains of 13 kinds of dominant pathogens were isolated. The dominant pathogens for respiratory tract infection were Monilia albican (23.7%), Klebsiella pneumoniae (12.9%), Pseudomonas aeruginosa (11.6%), Escherichia coli (9.5%), Candida glabrata (9.1%), Acinetobacter baumanii (7.9%), Aspergillus (6.7%), Stenotrophomonas maltophilia (4.5%), coagulase negative Staphylococcus (3.7%) and some species of Pseudomonas (3.7%), Staphylococcus aureus (3.0%), Aerobacter cloacae (1.9%), and Candida tropicalis (1.8%). A total of 6 198 strains of 7 kinds of Gram negative (G - ) bacilli infection dominant pathogens accounts for 52.0% of all infections, Klebsiella pneumonia (24.8%), Pseudomonas aeruginosa (22.3%), Escherichia coli (18.2%) and Acinetobacter baumanii (15.3%) were the main pathogens, and increased year by year. Susceptibility analysis showed that the preferred antibiotics for G - bacteria were carbapenems, followed by risperidone, sulbactam, cefepime, amikacin, and the third generation of cephalosporins. A total of 798 strains of 2 kinds of Gram positive (G + ) bacilli infection dominant pathogens accounted for 6.7% of all infections, were coagulase negative Staphylococcus (54.8%) and Staphylococcus aureus (45.2%), each had changed little by year. Susceptibility analysis showed that G + bacteria were sensitive to glycopeptides, followed by cefoxitin, cotrimoxazole, the tetracyclines, quinolones, azithromycin, erythromycin and so on. The advantages of 4 species of fungi were 4 913 strains, accounted for all of the 41.3% strains, with 57.5% of Candida albicans, and the trend was increasing year by year. Susceptibility analysis results showed that the antifungal susceptibility of dominant fungi were higher. G - bacilli is still the main source of infection, and showed an upward trend year by year. Fungal infection rate cannot be ignored, and we must pay attention to fungal infection incentives. We should strengthen the rational use of antibiotics.

Indolo[3,2-a]carbazoles from a deep-water sponge of the genus Asteropus.

PubMed

Russell, Floyd; Harmody, Dedra; McCarthy, Peter J; Pomponi, Shirley A; Wright, Amy E

2013-10-25

Two new indolo[3,2-a]carbazoles (1, 2) were isolated from a deep-water collection of a sponge of the genus Asteropus. The structures of 1 and 2 were determined through the analysis of spectroscopic data including mass spectrometry and 2D-NMR. Compound 1 showed minimum inhibitory concentrations of 25 μg/mL against the fungal pathogen Candida albicans and 50 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA). Compounds 1 and 2 showed no cytotoxicity against the PANC1 human pancreatic carcinoma and NCI/ADR-RES ovarian adenocarcinoma cell lines at our standard test concentration of 5 μg/mL.

Indolo[3,2-a]carbazoles from a Deep-Water Sponge of the Genus Asteropus

PubMed Central

2013-01-01

Two new indolo[3,2-a]carbazoles (1, 2) were isolated from a deep-water collection of a sponge of the genus Asteropus. The structures of 1 and 2 were determined through the analysis of spectroscopic data including mass spectrometry and 2D-NMR. Compound 1 showed minimum inhibitory concentrations of 25 μg/mL against the fungal pathogen Candida albicans and 50 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA). Compounds 1 and 2 showed no cytotoxicity against the PANC1 human pancreatic carcinoma and NCI/ADR-RES ovarian adenocarcinoma cell lines at our standard test concentration of 5 μg/mL. PMID:24063539

In Vitro Activity of Miltefosine against Candida albicans under Planktonic and Biofilm Growth Conditions and In Vivo Efficacy in a Murine Model of Oral Candidiasis

PubMed Central

Chaturvedi, Ashok K.; Rozental, Sonia

2015-01-01

The generation of a new antifungal against Candida albicans biofilms has become a major priority, since biofilm formation by this opportunistic pathogenic fungus is usually associated with an increased resistance to azole antifungal drugs and treatment failures. Miltefosine is an alkyl phospholipid with promising antifungal activity. Here, we report that, when tested under planktonic conditions, miltefosine displays potent in vitro activity against multiple fluconazole-susceptible and -resistant C. albicans clinical isolates, including isolates overexpressing efflux pumps and/or with well-characterized Erg11 mutations. Moreover, miltefosine inhibits C. albicans biofilm formation and displays activity against preformed biofilms. Serial passage experiments confirmed that miltefosine has a reduced potential to elicit resistance, and screening of a library of C. albicans transcription factor mutants provided additional insight into the activity of miltefosine against C. albicans growing under planktonic and biofilm conditions. Finally, we demonstrate the in vivo efficacy of topical treatment with miltefosine in the murine model of oropharyngeal candidiasis. Overall, our results confirm the potential of miltefosine as a promising antifungal drug candidate, in particular for the treatment of azole-resistant and biofilm-associated superficial candidiasis. PMID:26416861

Frequency and antimicrobial susceptibility of aerobic bacterial vaginal isolates.

PubMed

Tariq, Nabia; Jaffery, Tara; Ayub, Rukhsana; Alam, Ali Yawar; Javid, Mahmud Haider; Shafique, Shamsa

2006-03-01

To determine the frequency and antimicrobial susceptibility of aerobic bacterial isolates from high vaginal swab cultures. Cross-sectional survey. Shifa International Hospital, Islamabad, from January 2003 to February 2004. The subjects included 136 symptomatic women attending Obstetrics and Gynecology Out-Patient Department. A proforma was filled to document the demographic details, presenting complaint and examination findings. High vaginal swabs were taken for gram staining, culture and antimicrobial sensitivity testing using standard microbiologic techniques. Normal flora was isolated in 30% of the cases, followed by Candida spp. (21.3%), Enterococcus spp. (14.7%), E.coli (10.2%), Beta hemolytic Streptococcus spp. (7.3%), Staphylococcus spp. (4.4%), Enterobacter spp. (4.4%), while Streptococcus pyogenes, Staphylococcus epidermidis and Klebsiella spp. were isolated 1.5% each. Enterococcus, Staphylococcus and Streptococcus were mostly sensitive to penicillin and amoxicillin while E.coli and Klebsiella were sensitive to (piperacillin-Tazobactum, Imipenem and vancomycin. Enterococci species showed significant resistance to aminoglycoside antibiotics (68.8% to 81.3%) resistance to vancomycin was 5%. Thirty percent of symptomatic patients had normal flora on culture. Candida spp was the most frequent pathogen isolated. Co-amoxiclav should be used as empiric therapy until culture-sensitivity report is available.

Anti-Candida albicans natural products, sources of new antifungal drugs: A review.

PubMed

Zida, A; Bamba, S; Yacouba, A; Ouedraogo-Traore, R; Guiguemdé, R T

2017-03-01

Candida albicans is the most prevalent fungal pathogen in humans. Due to the development of drug resistance, there is today a need for new antifungal agents for the efficient management of C. albicans infections. Therefore, we reviewed antifungal activity, mechanisms of action, possible synergism with antifungal drugs of all natural substances experimented to be efficient against C. albicans for future. An extensive and systematic review of the literature was undertaken and all relevant abstracts and full-text articles analyzed and included in the review. A total of 111 documents were published and highlighted 142 anti-C. albicans natural products. These products are mostly are reported in Asia (44.37%) and America (28.17%). According to in vitro model criteria, from the 142 natural substances, antifungal activity can be considered as important for 40 (28.20%) and moderate for 24 (16.90%). Sixteen products have their antifungal activity confirmed by in vivo gold standard experimentation. Microbial natural products, source of antifungals, have their antifungal mechanism well described in the literature: interaction with ergosterol (polyenes), inhibition 1,3-β-d-glucan synthase (Echinocandins), inhibition of the synthesis of cell wall components (chitin and mannoproteins), inhibition of sphingolipid synthesis (serine palmitoyltransferase, ceramide synthase, inositol phosphoceramide synthase) and inhibition of protein synthesis (sordarins). Natural products from plants mostly exert their antifungal effects by membrane-active mechanism. Some substances from arthropods are also explored to act on the fungal membrane. Interestingly, synergistic effects were found between different classes of natural products as well as between natural products and azoles. Search for anti-C. albicans new drugs is promising since the list of natural substances, which disclose activity against this yeast is today long. Investigations must be pursued not only to found more new anti-Candida compounds from plants and organisms but also to carried out details on molecules from already known anti-Candida compounds and to more elucidate mechanisms of action. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Targeting and synergistic action of an antifungal peptide in an antibiotic drug-delivery system.

PubMed

Park, Seong-Cheol; Kim, Young-Min; Lee, Jong-Kook; Kim, Nam-Hong; Kim, Eun-Ji; Heo, Hun; Lee, Min-Young; Lee, Jung Ro; Jang, Mi-Kyeong

2017-06-28

Amphotericin B (AmB) has been widely used against fungal infections throughout almost the entire body, including the skin, nails, oral cavity, respiratory tract, and urinary tract. However, the development of AmB-loaded nanoparticles demands a novel technique that reduces its toxicity and other associated problems. Here, we developed a pH-responsive and redox-sensitive polymer-based AmB-delivery carrier system. In particular, this system was functionalized by conjugation with the antifungal peptide histatin 5, which acts both as a targeting ligand and a synergistic antifungal molecule against Candida albicans, a major systemic fungal pathogen of humans. Our results in vitro and in vivo suggest that this drug-delivery system may serve as a novel tool to facilitate the use of antimicrobial peptides as targeting ligands to pathogenic microbes, which would open new avenues of investigation in the field of drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

Candida albicans gastrointestinal colonization and invasion in the mouse: effect of antibacterial dosing, antifungal therapy and immunosuppression.

PubMed

Kinsman, O S; Pitblado, K

1989-12-01

Infant mice infected with Candida albicans by the oral-intragastric route became colonized in the gut and were persistently colonized into adulthood. Faecal levels of Candida were correlated with total gastrointestinal Candida and provided a useful means of detecting yeast overgrowth or elimination. Antibacterial agents promoting Candida overgrowth when given by the oral or parenteral route included ceftriaxone, augmentin and cefoperazone. Ceftizoxime had less effect. Ceftazidime and latamoxef produced raised levels only by the oral route. Gentamicin, vancomycin and metronidazole did not affect the Candida levels. Dosing with some antibacterials promoted an increase in gastrointestinal Candida and invasion to a greater extent than immunosuppression. Antifungal therapy to reduce gastrointestinal colonization was investigated using amphotericin B, nystatin, ketoconazole, intraconazole and fluconazole. Fluconazole was most effective at reducing faecal Candida.

Aloe vera extract reduces both growth and germ tube formation by Candida albicans.

PubMed

Bernardes, Ivy; Felipe Rodrigues, Monalisa Poliana; Bacelli, Gabrielle Klug; Munin, Egberto; Alves, Leandro Procópio; Costa, Maricilia Silva

2012-05-01

Due to the increased number of immunocompromised patients, the infections associated with the pathogen of the genus Candida have significantly increased in recent years. To grow, Candida albicans may form a germ tube extension from the cells, which is essential for virulence. In this work, we studied the effect of crude glycolic extract of Aloe vera fresh leaves (20% w/v) on growth and germ tube formation by C. albicans. The C. albicans growth was determined in the presence of different concentrations of A. vera extracts in Sabouraud dextrose broth medium. In the presence of A. vera extract (10% v/v), the pronounced inhibition in the C. albicans growth (90-100%) was observed. This inhibition occurred parallel to the decrease in the germ tube formation induced by goat serum. Our results demonstrated that A. vera fresh leaves plant extract can inhibit both the growth and the germ tube formation by C. albicans. Our results suggest the possibility that A. vera extract may be used as a promising novel antifungal treatment. © 2011 Blackwell Verlag GmbH.

Rapid Hypothesis Testing with Candida albicans through Gene Disruption with Short Homology Regions

PubMed Central

Wilson, R. Bryce; Davis, Dana; Mitchell, Aaron P.

1999-01-01

Disruption of newly identified genes in the pathogen Candida albicans is a vital step in determination of gene function. Several gene disruption methods described previously employ long regions of homology flanking a selectable marker. Here, we describe disruption of C. albicans genes with PCR products that have 50 to 60 bp of homology to a genomic sequence on each end of a selectable marker. We used the method to disrupt two known genes, ARG5 and ADE2, and two sequences newly identified through the Candida genome project, HRM101 and ENX3. HRM101 and ENX3 are homologous to genes in the conserved RIM101 (previously called RIM1) and PacC pathways of Saccharomyces cerevisiae and Aspergillus nidulans. We show that three independent hrm101/hrm101 mutants and two independent enx3/enx3 mutants are defective in filamentation on Spider medium. These observations argue that HRM101 and ENX3 sequences are indeed portions of genes and that the respective gene products have related functions. PMID:10074081

Candida albicans Biofilms Do Not Trigger Reactive Oxygen Species and Evade Neutrophil Killing

PubMed Central

Xie, Zhihong; Thompson, Angela; Sobue, Takanori; Kashleva, Helena; Xu, Hongbin; Vasilakos, John; Dongari-Bagtzoglou, Anna

2012-01-01

Neutrophils are found within Candida albicans biofilms in vivo and could play a crucial role in clearing the pathogen from biofilms forming on catheters and mucosal surfaces. Our goal was to compare the antimicrobial activity of neutrophils against developing and mature C. albicans biofilms and identify biofilm-specific properties mediating resistance to immune cells. Antibiofilm activity was measured with the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)2H-tetrazolium-5-carboxanilide assay and a molecular Candida viability assay. Reactive oxygen species generation was assessed by measuring fluorescence of 5-(and-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate, acetyl ester in preloaded neutrophils. We found that mature biofilms were resistant to leukocytic killing and did not trigger reactive oxygen species, even though neutrophils retained their viability and functional activation potential. Beta-glucans found in the extracellular matrix negatively affected antibiofilm activities. We conclude that these polymers act as a decoy mechanism to prevent neutrophil activation and that this represents an important innate immune evasion mechanism of C. albicans biofilms. PMID:23033146

Study of virulence factor of Candida species in oral lesions and its association with potentially malignant and malignant lesions.

PubMed

Castillo, Graciela Del Valle; Blanc, Silvia López de; Sotomayor, Claudia Elena; Azcurra, Ana Isabel

2018-07-01

The aim of this study was to explore the association between malignant and premalignant lesions and the virulence factor profile of Candida spp. recovered from different oral lesions. Candida spp. isolated from malignant lesions (squamous cell carcinoma, OC, n = 25), atypical lichen planus (AL, n = 11), chronic candidiasis (CC, n = 25), and asymptomatic carriers (WI, n = 15, control strains.) Isolates were identified in chromogenic medium, colony morphology and biochemical tests. The lipolytic and proteinase activity was determined on supplemented agar with olive oil and BSA, respectively. The biofilm formation with XTT reduction assay and cellular surface hydrophobicity (CSH) by water-hydrocarbon method were performed. All isolates recovered from oral lesions produced the four virulence factors studied with significantly higher levels than in WI isolates. Interestingly, lipolytic activity was absent in WI isolates. The proteolytic activity was similar in AL and OC isolates. OC isolates showed significantly higher CSH values than other clinical isolates. Non-albicans species showed higher biofilm formation than C.albicans (P = 0.03.) There were no significant differences in virulence factors among species. A strong positive correlation was found between proteinase and lipase activity (r = 0.90, P < 0.0001), and between hydrophobicity and biofilm (R = 0.81, P < 0.0001.) CONCLUSIONS: Our results indicate that OC Candida isolates exhibited a significant higher attributes of virulence than other lesions fungus isolates, providing evidence about the association between Candida pathogenicity and lesions severity. Copyright © 2018. Published by Elsevier Ltd.

PgTeL, the lectin found in Punica granatum juice, is an antifungal agent against Candida albicans and Candida krusei.

PubMed

da Silva, Pollyanna Michelle; de Moura, Maiara Celine; Gomes, Francis Soares; da Silva Trentin, Danielle; Silva de Oliveira, Ana Patrícia; de Mello, Gabriela Souto Vieira; da Rocha Pitta, Maira Galdino; de Melo Rego, Moacyr Jesus Barreto; Coelho, Luana Cassandra Breitenbach Barroso; Macedo, Alexandre José; de Figueiredo, Regina Celia Bressan Queiroz; Paiva, Patrícia Maria Guedes; Napoleão, Thiago Henrique

2018-03-01

The pomegranate (Punica granatum) sarcotesta contains a chitin-binding lectin (PgTeL) with antibacterial activity against human pathogenic species. In this work, the structural stability of PgTeL was evaluated by fluorimetric analysis and the lectin was evaluated for cytotoxicity to human peripheral blood mononuclear cells (PBMCs) and antifungal activity against Candida albicans and Candida krusei. PgTeL folding was impaired when lectin was incubated at pH≥6.0. On the other hand, the lectin did not undergo unfolding even when heated at 100°C. PgTeL (1, 10, and 100μg/mL) was not cytotoxic to PBMCs. Antifungal activity was detected for C. albicans (MIC: 25μg/mL; MFC: 50μg/mL) and C. krusei (MIC and MFC of 12.5μg/mL). Treatment of yeast cells with PgTeL resulted in decrease of intracellular ATP content even at sub-inhibitory concentrations (½MIC and ¼MIC) and induced lipid peroxidation. In addition, PgTeL damaged the integrity of fungal cell wall of both species, with more pronounced effects in C. krusei. The lectin showed significant antibiofilm activity on C. albicans at sub-inhibitory concentrations (0.195 and 0.39μg/mL). In conclusion, PgTeL is an anti-Candida agent whose action mechanism involves oxidative stress, energetic collapse, damage to the cell wall and rupture of yeast cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Volatile organic compounds produced by antarctic strains of candida sake play a role in the control of postharvest pathogens of apples

USDA-ARS?s Scientific Manuscript database

In this study the strategy of isolating psychrotrophic, non-pectinolytic yeasts able to grow in apple juice as potential biocontrol agents was a successful approach. Thirty-four yeasts isolated from Antarctic were able to maintain rot incidence caused by P. expansum and B. cinerea under 25% on appl...

Rapid Methods for the Laboratory Identification of Pathogenic Microorganisms.

DTIC Science & Technology

1981-09-01

Preliminary results provide strong evidence to show that the fungi, Candida and Cryptococcus , can be raoidly differentiated by a lectin test. SFor Oro...SUMMATION LECTIN-YEAST INTERACTIONS Objective: To find a lectin that selectively agglutinates Cryptococcus neoformans (the etiologic agent of...peanut), Conavalia ensiformis (Con A) and mango extract may potentially be utilized to differentiate Cryptococcus from the other yeasts most commonly

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

A novel small molecule methyltransferase is important for virulence in Candida albicans.

PubMed

Lissina, Elena; Weiss, David; Young, Brian; Rella, Antonella; Cheung-Ong, Kahlin; Del Poeta, Maurizio; Clarke, Steven G; Giaever, Guri; Nislow, Corey

2013-12-20

Candida albicans is an opportunistic pathogen capable of causing life-threatening infections in immunocompromised individuals. Despite its significant health impact, our understanding of C. albicans pathogenicity is limited, particularly at the molecular level. One of the largely understudied enzyme families in C. albicans are small molecule AdoMet-dependent methyltransferases (smMTases), which are important for maintenance of cellular homeostasis by clearing toxic chemicals, generating novel cellular intermediates, and regulating intra- and interspecies interactions. In this study, we demonstrated that C. albicans Crg1 (CaCrg1) is a bona fide smMTase that interacts with the toxin in vitro and in vivo. We report that CaCrg1 is important for virulence-related processes such as adhesion, hyphal elongation, and membrane trafficking. Biochemical and genetic analyses showed that CaCrg1 plays a role in the complex sphingolipid pathway: it binds to exogenous short-chain ceramides in vitro and interacts genetically with genes of glucosylceramide pathway, and the deletion of CaCRG1 leads to significant changes in the abundance of phytoceramides. Finally we found that this novel lipid-related smMTase is required for virulence in the waxmoth Galleria mellonella, a model of infection.

Silver nanoparticle production by the fungus Fusarium oxysporum: nanoparticle characterisation and analysis of antifungal activity against pathogenic yeasts

PubMed Central

Ishida, Kelly; Cipriano, Talita Ferreira; Rocha, Gustavo Miranda; Weissmüller, Gilberto; Gomes, Fabio; Miranda, Kildare; Rozental, Sonia

2013-01-01

The microbial synthesis of nanoparticles is a green chemistry approach that combines nanotechnology and microbial biotechnology. The aim of this study was to obtain silver nanoparticles (SNPs) using aqueous extract from the filamentous fungus Fusarium oxysporum as an alternative to chemical procedures and to evaluate its antifungal activity. SNPs production increased in a concentration-dependent way up to 1 mM silver nitrate until 30 days of reaction. Monodispersed and spherical SNPs were predominantly produced. After 60 days, it was possible to observe degenerated SNPs with in additional needle morphology. The SNPs showed a high antifungal activity against Candida and Cryptococcus , with minimum inhibitory concentration values ≤ 1.68 µg/mL for both genera. Morphological alterations of Cryptococcus neoformans treated with SNPs were observed such as disruption of the cell wall and cytoplasmic membrane and lost of the cytoplasm content. This work revealed that SNPs can be easily produced by F. oxysporum aqueous extracts and may be a feasible, low-cost, environmentally friendly method for generating stable and uniformly sized SNPs. Finally, we have demonstrated that these SNPs are active against pathogenic fungi, such as Candida and Cryptococcus . PMID:24714966

Silver nanoparticle production by the fungus Fusarium oxysporum: nanoparticle characterisation and analysis of antifungal activity against pathogenic yeasts.

PubMed

Ishida, Kelly; Cipriano, Talita Ferreira; Rocha, Gustavo Miranda; Weissmüller, Gilberto; Gomes, Fabio; Miranda, Kildare; Rozental, Sonia

2014-04-01

The microbial synthesis of nanoparticles is a green chemistry approach that combines nanotechnology and microbial biotechnology. The aim of this study was to obtain silver nanoparticles (SNPs) using aqueous extract from the filamentous fungus Fusarium oxysporum as an alternative to chemical procedures and to evaluate its antifungal activity. SNPs production increased in a concentration-dependent way up to 1 mM silver nitrate until 30 days of reaction. Monodispersed and spherical SNPs were predominantly produced. After 60 days, it was possible to observe degenerated SNPs with in additional needle morphology. The SNPs showed a high antifungal activity against Candida and Cryptococcus , with minimum inhibitory concentration values ≤ 1.68 µg/mL for both genera. Morphological alterations of Cryptococcus neoformans treated with SNPs were observed such as disruption of the cell wall and cytoplasmic membrane and lost of the cytoplasm content. This work revealed that SNPs can be easily produced by F. oxysporum aqueous extracts and may be a feasible, low-cost, environmentally friendly method for generating stable and uniformly sized SNPs. Finally, we have demonstrated that these SNPs are active against pathogenic fungi, such as Candida and Cryptococcus.

Immune Protection against Lethal Fungal-Bacterial Intra-Abdominal Infections.

PubMed

Lilly, Elizabeth A; Ikeh, Melanie; Nash, Evelyn E; Fidel, Paul L; Noverr, Mairi C

2018-01-16

Polymicrobial intra-abdominal infections (IAIs) are clinically prevalent and cause significant morbidity and mortality, especially those involving fungi. Our laboratory developed a mouse model of IAI and demonstrated that intraperitoneal inoculation with Candida albicans or other virulent non- albicans Candida (NAC) species plus Staphylococcus aureus resulted in 70 to 80% mortality in 48 to 72 h due to robust local and systemic inflammation (sepsis). Surprisingly, inoculation with Candida dubliniensis or Candida glabrata with S. aureus resulted in minimal mortality, and rechallenge of these mice with lethal C. albicans / S. aureus (i.e., coninfection) resulted in >90% protection. The purpose of this study was to define requirements for C. dubliniensis / S. aureus -mediated protection and interrogate the mechanism of the protective response. Protection was conferred by C. dubliniensis alone or by killed C. dubliniensis plus live S. aureus S. aureus alone was not protective, and killed S. aureus compromised C. dubliniensis -induced protection. C. dubliniensis / S. aureus also protected against lethal challenge by NAC plus S. aureus and could protect for a long-term duration (60 days between primary challenge and C. albicans/S. aureus rechallenge). Unexpectedly, mice deficient in T and B cells (Rag-1 knockouts [KO]) survived both the initial C. dubliniensis/S. aureus challenge and the C. albicans/S. aureus rechallenge, indicating that adaptive immunity did not play a role. Similarly, mice depleted of macrophages prior to rechallenge were also protected. In contrast, protection was associated with high numbers of Gr-1 hi polymorphonuclear leukocytes (PMNLs) in peritoneal lavage fluid within 4 h of rechallenge, and in vivo depletion of Gr-1 + cells prior to rechallenge abrogated protection. These results suggest that Candida species can induce protection against a lethal C. albicans / S. aureus IAI that is mediated by PMNLs and postulated to be a unique form of trained innate immunity. IMPORTANCE Polymicrobial intra-abdominal infections are clinically devastating infections with high mortality rates, particularly those involving fungal pathogens, including Candida species. Even in patients receiving aggressive antimicrobial therapy, mortality rates remain unacceptably high. There are no available vaccines against IAI, which is complicated by the polymicrobial nature of the infection. IAI leads to lethal systemic inflammation (sepsis), which is difficult to target pharmacologically, as components of the inflammatory response are also needed to control the infection. Our studies demonstrate that prior inoculation with low-virulence Candida species provides strong protection against subsequent lethal infection with C. albicans and S. aureus Surprisingly, protection is long-lived but not mediated by adaptive (specific) immunity. Instead, protection is dependent on cells of the innate immune system (nonspecific immunity) and provides protection against other virulent Candida species. This discovery implies that a form of trained innate immunity may be clinically effective against polymicrobial IAI. Copyright © 2018 Lilly et al.

[Candida and Aspergillus infections in the light of a new list of alarm factors on the example of the Lodz Medical University Hospital No. 1].

PubMed

Tyczkowska-Sieroń, Ewa; Bartoszko-Tyczkowska, Anna

2012-01-01

In 2011, the Polish Ministry of Health introduced Candida sp. resistant to fluconazole and Aspergillus sp. to the list of Alarm Factors as alert pathogens. The purpose of this paper is to confirm the validity of continuous monitoring of fungal infections caused by the pathogens mentioned above. The role offluconazole therapy in the Candida sp. infections is also discussed. The analysis of the fungal infections is performed based on the results obtained in the University Clinic Hospital (UCH) No. 1 in Lodz in 2009-2011. The swabs were plated on Sabouraud's agar. Body fluids and blood were incubated in an automated system Bactec 9050. Yeast ID Phoenix BD panels were used to determine the species of fungi. In turn, antimicrobial susceptibility testing was carried out by E-tests (bioMerieux). In the analysis of fungal infections occurring among patients in the UCH No. 1 in Lodz in 2009-2011, C. albicans, C. non-albicans and Aspergillus sp. infections are taken into account. This analysis is performed based on relations of the number of infections (per 100 patients) versus six-month periods. As one can see in Fig. 1, a clear, linear and statistically significant increase in the number of C. albicans and C. non-albicans infections is observed throughout the entire time period under discussion. On the other hand, the number of Aspergillus sp. infections remains at an almost constant low level. The more detailed analysis of fungal infections in the different hospital units, which are particularly exposed to this type of infections (Figs. 2-6), shows that there is a clear correlation between the number of C. non-albicans infections and the frequency of therapy with fluconazole. The results presented in this paper show in the example of the UCH No. 1 in Lodz that the number of infections caused by C. albicans and C. non-albicans resistant to fluconazole is clearly increasing in a hospital environment in recent years, which is a great clinical problem. Although the number of Aspergillus sp. infections is relatively much lower in comparison to that of Candidia sp., these infections also constitute a problem of clinical importance. In light of the presented analysis, it should be assessed positively the fact that Candida sp. resistant to fluconazole and Aspergillus sp. are considered to be alert pathogens that require the continuous monitoring.

Yeasts of the genital region of patients attending the dermatology service at Hospital São Paulo, Brazil.

PubMed

Bentubo, Henri Donnarumma Levy; Mantovani, Ariane; Yamashita, Jane Tomimori; Gambale, Walderez; Fischman, Olga

2015-01-01

The knowledge of the diversity of yeasts that make up the skin microbiota of human beings is essential for the efficient monitoring of infections to which a person may be predisposed. This study identified yeasts comprising the genital skin microbiota of patients attending the Dermatology Service at the Hospital São Paulo-UNIFESP, Brazil. Samples were collected from the genital region of each patient and cultured on Sabouraud dextrose agar. Individual colonies were carefully transferred to tubes daily. Yeasts were identified based on classical methodologies and confirmed using a commercial kit. Eighty-three patients were included in the study. Approximately 80% were women and 20% were men. The average age was 55 years. Hypertension, diabetes, kidney transplant and AIDS were the main underlying diseases reported by the patients. The most prevalent yeasts were Candida parapsilosis (36.1%), Rhodotorula mucilaginosa (9.2%), Rhodotorula glutinis (8.3%), Candida tropicalis (5.5%) and Trichosporon inkin (1.8%). Approximately 78% of the isolates were obtained in pure cultures. Trichosporon inkin was isolated only from women, in contrast to literature describing a high prevalence in males. Our results suggest that Candida albicans is not the main yeast found on genital skin as previously thought, and opportunistic pathogens such as C. parapsilosis, C. tropicalis, Rhodotorula spp. and T. inkin make up the genital skin microbiota, representing a risk for infection in immunocompromised subjects. These results also indicate that women are carriers of T. inkin, the etiological agent of white piedra and trichosporonosis. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. 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.

Rab14 Regulates Maturation of Macrophage Phagosomes Containing the Fungal Pathogen Candida albicans and Outcome of the Host-Pathogen Interaction

PubMed Central

Okai, Blessing; Lyall, Natalie; Gow, Neil A. R.; Erwig, Lars-Peter

2015-01-01

Avoidance of innate immune defense is an important mechanism contributing to the pathogenicity of microorganisms. The fungal pathogen Candida albicans undergoes morphogenetic switching from the yeast to the filamentous hyphal form following phagocytosis by macrophages, facilitating its escape from the phagosome, which can result in host cell lysis. We show that the intracellular host trafficking GTPase Rab14 plays an important role in protecting macrophages from lysis mediated by C. albicans hyphae. Live-cell imaging of macrophages expressing green fluorescent protein (GFP)-tagged Rab14 or dominant negative Rab14, or with small interfering RNA (siRNA)-mediated knockdown of Rab14, revealed the temporal dynamics of this protein and its influence on the maturation of macrophage phagosomes following the engulfment of C. albicans cells. Phagosomes containing live C. albicans cells became transiently Rab14 positive within 2 min following engulfment. The duration of Rab14 retention on phagosomes was prolonged for hyphal cargo and was directly proportional to hyphal length. Interference with endogenous Rab14 did not affect the migration of macrophages toward C. albicans cells, the rate of engulfment, the overall uptake of fungal cells, or early phagosome processing. However, Rab14 depletion delayed the acquisition of the late phagosome maturation markers LAMP1 and lysosomal cathepsin, indicating delayed formation of a fully bioactive lysosome. This was associated with a significant increase in the level of macrophage killing by C. albicans. Therefore, Rab14 activity promotes phagosome maturation during C. albicans infection but is dysregulated on the phagosome in the presence of the invasive hyphal form, which favors fungal survival and escape. PMID:25644001

Combinatorial drug approaches to tackle Candida albicans biofilms.

PubMed

De Cremer, Kaat; Staes, Ines; Delattin, Nicolas; Cammue, Bruno P A; Thevissen, Karin; De Brucker, Katrijn

2015-08-01

The human fungal opportunistic pathogen Candida albicans resides in the human gut, genitourinary tract and on the skin. The majority of infections caused by C. albicans are biofilm-related. In the first part of this review, we discuss new insights into C. albicans biofilm characteristics, concentrating on the extracellular matrix, phenotypic switching, efflux pumps and persister cells. It is widely accepted that this multicellular lifestyle is more resistant to traditional antifungal treatment compared to free-living cells. Therefore, much effort is put in the search for combinations of drugs leading to synergistic interactions against microbial biofilms to achieve lower effective doses of the drugs. In the second part of this manuscript, we review all recently identified compounds that act synergistically with azoles, echinocandins and/or polyenes against C. albicans biofilms.

Phospholipid biosynthesis in Candida albicans: regulation by the precursors inositol and choline.

PubMed Central

Klig, L S; Friedli, L; Schmid, E

1990-01-01

Phospholipid metabolism in the pathogenic fungus Candida albicans was examined. The phospholipid biosynthetic pathways of C. albicans were elucidated and were shown to be similar to those of Saccharomyces cerevisiae. However, marked differences were seen between these two fungi in the regulation of the pathways in response to exogenously provided precursors inositol and choline. In S. cerevisiae, the biosynthesis of phosphatidylcholine via methylation of phosphatidylethanolamine appears to be regulated in response to inositol and choline; provision of choline alone does not repress the activity of this pathway (G. M. Carman and S. A. Henry, Annu. Rev. Biochem. 58:636-669, 1989). The same pathway in C. albicans responds to the exogenous provision of choline. Possible explanations for the observed differences in regulation are discussed. Images PMID:2198258

Development and regulation of single- and multi-species Candida albicans biofilms

PubMed Central

Lohse, Matthew B.; Gulati, Megha; Johnson, Alexander D.; Nobile, Clarissa J.

2017-01-01

Candida albicans is among the most prevalent fungal species of the human microbiota and asymptomatically colonizes healthy individuals. However, it is also an opportunistic pathogen that can cause severe, and often fatal, bloodstream infections. The medical impact of C. albicans typically depends on its ability to form biofilms, which are closely packed communities of cells that attach to surfaces, such as tissues and implanted medical devices. In this Review, we provide an overview of the processes involved in the formation of C. albicans biofilms and discuss the core transcriptional network that regulates biofilm development. We also consider some of the advantages that biofilms provide to C. albicans in comparison with planktonic growth and explore polymicrobial biofilms that are formed by C. albicans and certain bacterial species. PMID:29062072

In vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and the correlation between triazoles susceptibility: Results from a five-year study.

PubMed

Lei, J; Xu, J; Wang, T

2018-06-01

Candida spp. is a common cause of invasive fungal disease. The aim of this study was to examine the susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and explore the correlation between triazoles susceptibility. The antifungal susceptibility in the present study was measured by ATB Fungus 3 method, and the potential relationship was examined by obtaining the correlation of measured minimal inhibitory concentrations (MICs) of Candida spp. isolates. A total of 2099 clinical isolates of Candida spp. from 1441 patients were analyzed. The organisms included 1435 isolates of Candida albicans, 207 isolates of Candida glabrata, 65 isolates of Candida parapsilosis, 31 isolates of Candida krusei, 268 isolates of Candida tropicalis. Voriconazole and itraconazole were more active than fluconazole and against Candida spp. in vitro. The fluconazole, itraconazole and voriconazole MIC 90 (MIC for 90% of the isolates) for all Candida spp. isolates was 4mg/L, 1mg/L and 0.25mg/L, respectively. There was a moderate correlation between the fluconazole MIC s for Candida spp. isolates and this for voriconazole (R 2 =0.475; P<0.01) and itraconazole (R 2 =0.431; P<0.01). Voriconazole MICs for the Candida spp. isolates also correlated with those for itraconazole (R 2 =0.401; P<0.01). These observations suggest that the in vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole exhibits a moderate correlation. Published by Elsevier Masson SAS.

Two new species of the genus Candida in the Zygoascus clade, Candida lundiana sp. nov. and Candida suthepensis sp. nov., isolated from raw honey in Thailand.

PubMed

Saksinchai, Sujinan; Suzuki, Motofumi; Lumyong, Saisamorn; Ohkuma, Moriya; Chantawannakul, Panuwan

2012-03-01

During a survey of yeasts associated with raw honey collected in Thailand, two strains of the Zygoascus clade were isolated from the Asian cavity-nesting honeybee Apis cerana and the stingless bee Homotrigona fimbriata. Phylogeny based on 26S rDNA D1/D2 sequences placed these yeasts as members of a clade including Candida bituminiphila, Candida patagonica and Candida polysorbophila. The strains of the two novel species, CBS 12271(T) and CBS 12270(T), respectively, could be unquestionably distinguished from their relatives by rDNA sequences and other taxonomic characteristics. Therefore, the novel anamorphic species, Candida lundiana sp. nov. (type strain CBS 12271(T) = JCM 16823(T)) and Candida suthepensis sp. nov. (type strain CBS 12270(T) = JCM 16822(T)) are described.

[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.

Antifungal nanofibers made by controlled release of sea animal derived peptide

NASA Astrophysics Data System (ADS)

Viana, Juliane F. C.; Carrijo, Jéssica; Freitas, Camila G.; Paul, Arghya; Alcaraz, Jarib; Lacorte, Cristiano C.; Migliolo, Ludovico; Andrade, César A.; Falcão, Rosana; Santos, Nuno C.; Gonçalves, Sónia; Otero-González, Anselmo J.; Khademhosseini, Ali; Dias, Simoni C.; Franco, Octávio L.

2015-03-01

Candida albicans is a common human-pathogenic fungal species with the ability to cause several diseases including surface infections. Despite the clear difficulties of Candida control, antimicrobial peptides (AMPs) have emerged as an alternative strategy for fungal control. In this report, different concentrations of antifungal Cm-p1 (Cencritchis muricatus peptide 1) were electrospun into nanofibers for drug delivery. The nanofibers were characterized by mass spectrometry confirming the presence of the peptide on the scaffold. Atomic force microscopy and scanning electronic microscopy were used to measure the diameters, showing that Cm-p1 affects fiber morphology as well as the diameter and scaffold thickness. The Cm-p1 release behavior from the nanofibers demonstrated peptide release from 30 min to three days, leading to effective yeast control in the first 24 hours. Moreover, the biocompatibility of the fibers were evaluated through a MTS assay as well as ROS production by using a HUVEC model, showing that the fibers do not affect cell viability and only nanofibers containing 10% Cm-p1-PVA improved ROS generation. In addition, the secretion of pro-inflammatory cytokines IL-6 and TNF-α by the HUVECs was also slightly modified by the 10% Cm-p1-PVA nanofibers. In conclusion, the electrospinning technique applied here allowed for the manufacture of biodegradable biomimetic nanofibrous extracellular membranes with the ability to control fungal infection.Candida albicans is a common human-pathogenic fungal species with the ability to cause several diseases including surface infections. Despite the clear difficulties of Candida control, antimicrobial peptides (AMPs) have emerged as an alternative strategy for fungal control. In this report, different concentrations of antifungal Cm-p1 (Cencritchis muricatus peptide 1) were electrospun into nanofibers for drug delivery. The nanofibers were characterized by mass spectrometry confirming the presence of the peptide on the scaffold. Atomic force microscopy and scanning electronic microscopy were used to measure the diameters, showing that Cm-p1 affects fiber morphology as well as the diameter and scaffold thickness. The Cm-p1 release behavior from the nanofibers demonstrated peptide release from 30 min to three days, leading to effective yeast control in the first 24 hours. Moreover, the biocompatibility of the fibers were evaluated through a MTS assay as well as ROS production by using a HUVEC model, showing that the fibers do not affect cell viability and only nanofibers containing 10% Cm-p1-PVA improved ROS generation. In addition, the secretion of pro-inflammatory cytokines IL-6 and TNF-α by the HUVECs was also slightly modified by the 10% Cm-p1-PVA nanofibers. In conclusion, the electrospinning technique applied here allowed for the manufacture of biodegradable biomimetic nanofibrous extracellular membranes with the ability to control fungal infection. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00767d

Candidiasis: Prevalence and resistance profiling in a tertiary care hospital of Pakistan.

PubMed

Jamil, Bushra; Mukhtar Bokhari, Mohammad Tauseef; Saeed, Azhar; Mukhtar Bokhari, Mohammad Zahid; Hussain, Zakir; Khalid, Tayyaba; Bokhari, Habib; Imran, Mohammad; Abbasi, Shahid Ahmad

2017-05-01

To determine Candida colonisation/infection in renal transplant patients and to determine the resistance pattern against antifungal drugs. This prospective, observational study was conducted at Al-Sayyed Hospital, Rawalpindi, Pakistan, from January to October 2014, in collaboration with the Microbiology and Public Health Laboratory's, Islamabad campus..The clinical specimens investigated included respiratory tract secretions, blood, urine, high vaginal swab, skin scrapings, and plastic devices samples. Of the 7,850 samples, 164(2.08%) were positive for Candida. Candida albicans were most prevalent as they were found in 114(69%) samples. Besides, 56(34%) of the positive samples were resistant to one or more antifungal agents. Highest resistance was obtained against fluconazole. We found only 5(3.04%) positive samples of Candida glabrata; of them, 3(60%)were resistant. In case of Candida spp, 27(48%) resistance was observed. In Candida albicans, 23(41%) of the samples were found to be resistant. Most of the Candida isolates was recovered from bronchial alveolar lavage. Although Candida albicans remained the main responsible species for Candida infections, but non-albican Candida species are also emerging.

Resistance Patterns and Clinical Significance of Candida Colonization and Infection in Combat-Related Injured Patients From Iraq and Afghanistan

PubMed Central

Blyth, Dana M.; Mende, Katrin; Weintrob, Amy C.; Beckius, Miriam L.; Zera, Wendy C.; Bradley, William; Lu, Dan; Tribble, David R.; Murray, Clinton K.

2014-01-01

Background  Penetrating wounds with environmental contamination are associated with a range of infectious complications, including fungus. This is the first study to examine the epidemiology, resistance patterns, and outcomes of Candida infections and colonization in United States military patients injured in Iraq and Afghanistan. Methods  Clinical information associated with initial unique and serial Candida isolates collected from patients (June 2009–October 2013) through the Trauma Infectious Disease Outcomes Study (TIDOS) was evaluated. Susceptibilities were performed using Sensititre YeastOne (YO-9) plates and interpreted by Clinical Laboratory and Standards Institute (CLSI) and adjusted-European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. Results  The analysis included 127 patients with 131 unique Candida isolates, of which 102 were Candida albicans and 29 non-albicans Candida spp. Overall, 99% of patients were male with a median age of 23 and an injury severity score of 22. Injuries were primarily due to blasts (77%) and sustained among personnel serving in Afghanistan (89%). There was a median of 7 days from injury to Candida isolation, and 74 isolates were associated with infection. In the multivariate analysis, non-albicans Candida spp were associated with prior antifungal exposure, blood isolates, and wound isolates (P < .01). Nonsusceptibility by CLSI and EUCAST criteria was associated with non-albicans Candida spp (P < .05). Patients with Candida isolation had a 7.1% mortality rate, compared with 1.4% from the overall TIDOS population. Conclusions  Candida isolation from patients with penetrating war injuries may identify a population at higher risk for death. Prospective studies are needed to determine whether targeted antifungals and surgical management will affect this mortality rate. PMID:25734177

Dual-species relations between Candida tropicalis isolated from apple juice ultrafiltration membranes, with Escherichia coli O157:H7 and Salmonella sp.

PubMed

Tarifa, M C; Lozano, J E; Brugnoni, L I

2015-02-01

The objective of this study was to determine the interactions between common spoilage yeast, Candida tropicalis, isolated from ultrafiltration membranes, and Escherichia coli O157:H7 and Salmonella sp. on stainless steel surfaces. Single and dual-species attachment assays were performed on stainless steel at 25°C using apple juice as culture medium. The growth of Salmonella sp. rose when it was co-cultivated with C. tropicalis in dual biofilms at 16 and 24 h; the same effect was observed for E. coli O157:H7 at 24 h. The colonization of C. tropicalis on stainless steel surfaces was reduced when it was co-cultivated with both pathogenic bacteria, reducing C. tropicalis population by at least 1.0 log unit. Visualization by SEM demonstrated that E. coli O157:H7 and Salmonella sp. adhere closely to hyphal elements using anchorage structures to attach to the surface and other cells. These results suggest a route for potential increased survival of pathogens in juice processing environments. These support the notion that the species involved interact in mixed yeast-bacteria communities favouring the development of bacteria over yeast. This study support the plausibility that pathogen interactions with strong biofilm forming members of spoilage microbiota, such as C. tropicalis, might play an important role for the survival and dissemination of E. coli O157:H7 and Salmonella sp. in food-processing environments. © 2014 The Society for Applied Microbiology.

Role of the male partner in the lower genitourinary tract infection of female.

PubMed

Sahoo, B; Bhandari, H; Sharma, M; Malhotra, S; Sawhney, H; Kumar, B

2000-07-01

We studied the relationships of selected microbes and the role of consorts in the causation of vaginal discharge which may be due to cervicitis or vaginitis. A total of 93 consecutive patients in the reproductive age group with symptoms of vaginal discharge along with their sexual partners were studied. Samples were collected from the cervix and posterior fornix of the female patients and from the urethra and sub-prepucial area of the male partner for culture of Neisseria gonorrhoeae, Gardnerella vaginalis, Mycoplasma hominis, ureaplasma, candida, aerobic and anaerobic organisms. Apart from cultures, KOH and Gram stain of the discharge were made. Predominant pathogen isolated was Ureaplasma urealyticum from 40 (43.01%) females and 23 (24.7%) males. The next common pathogenic organisms isolated were candida species from 11 (11.8%) females and 5 (5.4%) males and Chlamydia trachomatis in 3 (3.2%) females and 1 (1.1%) male. Various organisms were more frequently isolated from the 29 of 43 (67.4%) couples who had had sexual intercourse 7 days prior to the recruitment as compared to 14 of 43 (32.6%) who had had coitus more than 7 days prior to their recruitment. This may be due to the spontaneous disappearance or decrease in the number of organisms to the level that they could be detected by culture. In our study, 6 (6.5%) of male partners carrying pathogenic organisms were asymptomatic, indicating that their screening and treatment is vital.

Cranberry proanthocyanidins inhibit the adherence properties of Candida albicans and cytokine secretion by oral epithelial cells

PubMed Central

2012-01-01

Background Oral candidiasis is a common fungal disease mainly caused by Candida albicans. The aim of this study was to investigate the effects of A-type cranberry proanthocyanidins (AC-PACs) on pathogenic properties of C. albicans as well as on the inflammatory response of oral epithelial cells induced by this oral pathogen. Methods Microplate dilution assays were performed to determine the effect of AC-PACs on C. albicans growth as well as biofilm formation stained with crystal violet. Adhesion of FITC-labeled C. albicans to oral epithelial cells and to acrylic resin disks was monitored by fluorometry. The effects of AC-PACs on C. albicans-induced cytokine secretion, nuclear factor-kappa B (NF-κB) p65 activation and kinase phosphorylation in oral epithelial cells were determined by immunological assays. Results Although AC-PACs did not affect growth of C. albicans, it prevented biofilm formation and reduced adherence of C. albicans to oral epithelial cells and saliva-coated acrylic resin discs. In addition, AC-PACs significantly decreased the secretion of IL-8 and IL-6 by oral epithelial cells stimulated with C. albicans. This anti-inflammatory effect was associated with reduced activation of NF-κB p65 and phosphorylation of specific signal intracellular kinases. Conclusion AC-PACs by affecting the adherence properties of C. albicans and attenuating the inflammatory response induced by this pathogen represent potential novel therapeutic agents for the prevention/treatment of oral candidiasis. PMID:22248145

Direct Isolation of Candida spp. from Blood Cultures on the Chromogenic Medium CHROMagar Candida

PubMed Central

Horvath, Lynn L.; Hospenthal, Duane R.; Murray, Clinton K.; Dooley, David P.

2003-01-01

CHROMagar Candida is a selective and differential chromogenic medium that has been shown to be useful for identification of Candida albicans, Candida krusei, Candida tropicalis, and perhaps Candida glabrata. Colony morphology and color have been well defined when CHROMagar Candida has been used to isolate yeast directly from clinical specimens, including stool, urine, respiratory, vaginal, oropharyngeal, and esophageal sources. Direct isolation of yeast on CHROMagar Candida from blood cultures has not been evaluated. We evaluated whether the color and colony characteristics produced by Candida spp. on CHROMagar Candida were altered when yeasts were isolated directly from blood cultures. Fifty clinical isolates of Candida were inoculated into aerobic and anaerobic blood culture bottles and incubated at 35°C in an automated blood culture system. When growth was detected, an aliquot was removed and plated onto CHROMagar Candida. As a control, CHROMagar Candida plates were inoculated with the same isolate of yeast grown on Sabouraud dextrose agar simultaneously. No significant difference was detected in color or colony morphology between the blood and control isolates in any of the tested organisms. All C. albicans (n = 12), C. tropicalis (n = 12), C. glabrata (n = 9), and C. krusei (n = 5) isolates exhibited the expected species-specific colony characteristics and color, whether isolated directly from blood or from control cultures. CHROMagar Candida can be reliably used for direct isolation of yeast from blood cultures. Direct isolation could allow mycology laboratories to more rapidly identify Candida spp., enable clinicians to more quickly make antifungal agent selections, and potentially decrease patient morbidity and mortality. PMID:12791890

Evaluation of Novel Broad-Range Real-Time PCR Assay for Rapid Detection of Human Pathogenic Fungi in Various Clinical Specimens▿

PubMed Central

Vollmer, Tanja; Störmer, Melanie; Kleesiek, Knut; Dreier, Jens

2008-01-01

In the present study, a novel broad-range real-time PCR was developed for the rapid detection of human pathogenic fungi. The assay targets a part of the 28S large-subunit ribosomal RNA (rDNA) gene. We investigated its application for the most important human pathogenic fungal genera, including Aspergillus, Candida, Cryptococcus, Mucor, Penicillium, Pichia, Microsporum, Trichophyton, and Scopulariopsis. Species were identified in PCR-positive reactions by direct DNA sequencing. A noncompetitive internal control was applied to prevent false-negative results due to PCR inhibition. The minimum detection limit for the PCR was determined to be one 28S rDNA copy per PCR, and the 95% detection limit was calculated to 15 copies per PCR. To assess the clinical applicability of the PCR method, intensive-care patients with artificial respiration and patients with infective endocarditis were investigated. For this purpose, 76 tracheal secretion samples and 70 heart valve tissues were analyzed in parallel by real-time PCR and cultivation. No discrepancies in results were observed between PCR analysis and cultivation methods. Furthermore, the application of the PCR method was investigated for other clinical specimens, including cervical swabs, nail and horny skin scrapings, and serum, blood, and urine samples. The combination of a broad-range real-time PCR and direct sequencing facilitates rapid screening for fungal infection in various clinical specimens. PMID:18385440

Evaluation of novel broad-range real-time PCR assay for rapid detection of human pathogenic fungi in various clinical specimens.

PubMed

Vollmer, Tanja; Störmer, Melanie; Kleesiek, Knut; Dreier, Jens

2008-06-01

In the present study, a novel broad-range real-time PCR was developed for the rapid detection of human pathogenic fungi. The assay targets a part of the 28S large-subunit ribosomal RNA (rDNA) gene. We investigated its application for the most important human pathogenic fungal genera, including Aspergillus, Candida, Cryptococcus, Mucor, Penicillium, Pichia, Microsporum, Trichophyton, and Scopulariopsis. Species were identified in PCR-positive reactions by direct DNA sequencing. A noncompetitive internal control was applied to prevent false-negative results due to PCR inhibition. The minimum detection limit for the PCR was determined to be one 28S rDNA copy per PCR, and the 95% detection limit was calculated to 15 copies per PCR. To assess the clinical applicability of the PCR method, intensive-care patients with artificial respiration and patients with infective endocarditis were investigated. For this purpose, 76 tracheal secretion samples and 70 heart valve tissues were analyzed in parallel by real-time PCR and cultivation. No discrepancies in results were observed between PCR analysis and cultivation methods. Furthermore, the application of the PCR method was investigated for other clinical specimens, including cervical swabs, nail and horny skin scrapings, and serum, blood, and urine samples. The combination of a broad-range real-time PCR and direct sequencing facilitates rapid screening for fungal infection in various clinical specimens.

Role of Nitrogen and Carbon Transport, Regulation, and Metabolism Genes for Saccharomyces cerevisiae Survival In Vivo†

PubMed Central

Kingsbury, Joanne M.; Goldstein, Alan L.; McCusker, John H.

2006-01-01

Saccharomyces cerevisiae is both an emerging opportunistic pathogen and a close relative of pathogenic Candida species. To better understand the ecology of fungal infection, we investigated the importance of pathways involved in uptake, metabolism, and biosynthesis of nitrogen and carbon compounds for survival of a clinical S. cerevisiae strain in a murine host. Potential nitrogen sources in vivo include ammonium, urea, and amino acids, while potential carbon sources include glucose, lactate, pyruvate, and fatty acids. Using mutants unable to either transport or utilize these compounds, we demonstrated that no individual nitrogen source was essential, while glucose was the most significant primary carbon source for yeast survival in vivo. Hydrolysis of the storage carbohydrate glycogen made a slight contribution for in vivo survival compared with a substantial requirement for trehalose hydrolysis. The ability to sense and respond to low glucose concentrations was also important for survival. In contrast, there was little or no requirement in vivo in this assay for any of the nitrogen-sensing pathways, nitrogen catabolite repression, the ammonium- or amino acid-sensing pathways, or general control. By using auxotrophic mutants, we found that some nitrogenous compounds (polyamines, methionine, and lysine) can be acquired from the host, while others (threonine, aromatic amino acids, isoleucine, and valine) must be synthesized by the pathogen. Our studies provide insights into the yeast-host environment interaction and identify potential antifungal drug targets. PMID:16682459

Systematic Genetic Screen for Transcriptional Regulators of the Candida albicans White-Opaque Switch

PubMed Central

Lohse, Matthew B.; Ene, Iuliana V.; Craik, Veronica B.; Hernday, Aaron D.; Mancera, Eugenio; Morschhäuser, Joachim; Bennett, Richard J.; Johnson, Alexander D.

2016-01-01

The human fungal pathogen Candida albicans can reversibly switch between two cell types named “white” and “opaque,” each of which is stable through many cell divisions. These two cell types differ in their ability to mate, their metabolic preferences and their interactions with the mammalian innate immune system. A highly interconnected network of eight transcriptional regulators has been shown to control switching between these two cell types. To identify additional regulators of the switch, we systematically and quantitatively measured white–opaque switching rates of 196 strains, each deleted for a specific transcriptional regulator. We identified 19 new regulators with at least a 10-fold effect on switching rates and an additional 14 new regulators with more subtle effects. To investigate how these regulators affect switching rates, we examined several criteria, including the binding of the eight known regulators of switching to the control region of each new regulatory gene, differential expression of the newly found genes between cell types, and the growth rate of each mutant strain. This study highlights the complexity of the transcriptional network that regulates the white–opaque switch and the extent to which switching is linked to a variety of metabolic processes, including respiration and carbon utilization. In addition to revealing specific insights, the information reported here provides a foundation to understand the highly complex coupling of white–opaque switching to cellular physiology. PMID:27280690

Risk factors for totally implantable venous access device-associated complications in cystic fibrosis.

PubMed

McCarthy, C; O'Carroll, O; O'Brien, M E; McEnery, T; Franciosi, A; Gunaratnam, C; McElvaney, N G

2018-05-01

Candidaemia is an important nosocomial infection, seen frequently in immunocompromised and critically ill patients and increasingly recognised in cystic fibrosis (CF) patients with totally implantable venous access devices (TIVADs). This study aims to investigate the incidence and risk factors for the development of TIVAD-associated candidaemia and to assess the rate of TIVAD-related complications in CF patients. A 10-year retrospective study was carried out on adult CF patients attending a single centre. Complications were recorded including the incidence of candidaemia and correlated to clinical parameters. Complication rates were calculated based on incidence per 1000 catheter days. Statistical analysis was performed using Mann-Whitney U test and Fisher's exact test. Fourteen cases of candidaemia were observed in the CF cohort, primarily caused by Candida parapsilosis and Candida albicans. Candidaemia was associated with lower FEV1 (p = 0.0117) and higher frequency of pulmonary exacerbation (p < 0.0001). A TIVAD complication rate of 0.337/1000 catheter days was observed in the CF cohort. Complications included venous thrombosis, stenosis, and port extrusion; complications were independently associated with more frequent pulmonary exacerbations (p = 0.04). TIVAD complications are observed more commonly in those with lower FEV1 and frequent pulmonary exacerbations, suggesting that candidaemia may be related to antibiotic use and furthermore can occur following invasive procedures causing translocation of fungal species allowing transformation from colonisation to pathogenic infection.

Peptides from the scorpion Vaejovis punctatus with broad antimicrobial activity.

PubMed

Ramírez-Carreto, Santos; Jiménez-Vargas, Juana María; Rivas-Santiago, Bruno; Corzo, Gerardo; Possani, Lourival D; Becerril, Baltazar; Ortiz, Ernesto

2015-11-01

The antimicrobial potential of two new non-disulfide bound peptides, named VpAmp1.0 (LPFFLLSLIPSAISAIKKI, amidated) and VpAmp2.0 (FWGFLGKLAMKAVPSLIGGNKSSSK) is here reported. These are 19- and 25-aminoacid-long peptides with +2 and +4 net charges, respectively. Their sequences correspond to the predicted mature regions from longer precursors, putatively encoded by cDNAs derived from the venom glands of the Mexican scorpion Vaejovis punctatus. Both peptides were chemically synthesized and assayed against a variety of microorganisms, including pathogenic strains from clinical isolates and strains resistant to conventional antibiotics. Two shorter variants, named VpAmp1.1 (FFLLSLIPSAISAIKKI, amidated) and VpAmp2.1 (FWGFLGKLAMKAVPSLIGGNKK), were also synthesized and tested. The antimicrobial assays revealed that the four synthetic peptides effectively inhibit the growth of both Gram-positive (Staphylococcus aureus and Streptococcus agalactiaea) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, with MICs in the range of 2.5-24.0 μM; yeasts (Candida albicans and Candida glabrata) with MICs of 3.1-50.0 μM; and two clinically isolated strains of Mycobacterium tuberculosis-including a multi-drug resistant one- with MICs in the range of 4.8-30.5 μM. A comparison between the activities of the original peptides and their derivatives gives insight into the structural/functional role of their distinctive residues. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Inhibition of gold nanoparticles (AuNPs) on pathogenic biofilm formation and invasion to host cells.

PubMed

Yu, Qilin; Li, Jianrong; Zhang, Yueqi; Wang, Yufan; Liu, Lu; Li, Mingchun

2016-05-25

Owing to the growing infectious diseases caused by eukaryotic and prokaryotic pathogens, it is urgent to develop novel antimicrobial agents against clinical pathogenic infections. Biofilm formation and invasion into the host cells are vital processes during pathogenic colonization and infection. In this study, we tested the inhibitory effect of Au nanoparticles (AuNPs) on pathogenic growth, biofilm formation and invasion. Interestingly, although the synthesized AuNPs had no significant toxicity to the tested pathogens, Candida albicans and Pseudomonas aeruginosa, the nanoparticles strongly inhibited pathogenic biofilm formation and invasion to dental pulp stem cells (DPSCs). Further investigations revealed that AuNPs abundantly bound to the pathogen cells, which likely contributed to their inhibitory effect on biofilm formation and invasion. Moreover, treatment of AuNPs led to activation of immune response-related genes in DPSCs, which may enhance the activity of host immune system against the pathogens. Zeta potential analysis and polyethylene glycol (PEG)/polyethyleneimine (PEI) coating tests further showed that the interaction between pathogen cells and AuNPs is associated with electrostatic attractions. Our findings shed novel light on the application of nanomaterials in fighting against clinical pathogens, and imply that the traditional growth inhibition test is not the only way to evaluate the drug effect during the screening of antimicrobial agents.

Use of cefoperazone/sulbactam in neonates.

PubMed

Ovali, Fahri; Gursoy, Tugba; Sari, Ilkay; Divrikli, Demet; Aktas, Alev

2012-02-01

Neonates are at high risk for nosocomial infections due to multidrug-resistant pathogens. The use of β-lactamase inhibitors in combination with β-lactam antibiotics broadens the antimicrobial spectrum. Cefoperazone/sulbactam is used in children but there are limited data on its usage in neonates. The purpose of the present study was therefore to evaluate the use of cefoperazone/sulbactam in the treatment of neonatal infections caused by multidrug-resistant pathogens. The records of neonates who were hospitalized and who received cefoperazone/sulbactam were reviewed. There were 90 infants who received cefoperazone/sulbactam. A pathogen could be isolated in 41 (45.6%) of the infants. In total, 17.1% of isolated pathogens were resistant to cefoperazone/sulbactam. Side-effects were seen in four of the infants. Two infants had cholestasis, one infant had neutropenia and one had superinfection with candida. Cefoperazone/sulbactam can be used in the treatment of nosocomial infections caused by multidrug-resistant pathogens in neonates. © 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.

Antifungal activity of different neem leaf extracts and the nimonol against some important human pathogens

PubMed Central

Mahmoud, D.A.; Hassanein, N.M.; Youssef, K.A.; Abou Zeid, M.A.

2011-01-01

This study was conducted to evaluate the effect of aqueous, ethanolic and ethyl acetate extracts from neem leaves on growth of some human pathogens (Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, Candida albicans and Microsporum gypseum) in vitro. Different concentrations (5, 10, 15 and 20%) prepared from these extracts inhibited the growth of the test pathogens and the effect gradually increased with concentration. The 20% ethyl acetate extract gave the strongest inhibition compared with the activity obtained by the same concentration of the other extracts. High Performance Liquid Chromatography (HPLC) analysis of ethyl acetate extract showed the presence of a main component (nimonol) which was purified and chemically confirmed by Nuclear Magnetic Resonance (NMR) spectroscopic analysis. The 20% ethyl acetate extract lost a part of its antifungal effect after pooling out the nimonol and this loss in activity was variable on test pathogens. The purified nimonol as a separate compound did not show any antifungal activity when assayed against all the six fungal pathogens. PMID:24031718

Epidemiologic and microbiologic evaluation of nosocomial infections associated with Candida spp in children: A multicenter study from Istanbul, Turkey.

PubMed

Sutcu, Murat; Salman, Nuran; Akturk, Hacer; Dalgıc, Nazan; Turel, Ozden; Kuzdan, Canan; Kadayifci, Eda Kepenekli; Sener, Dicle; Karbuz, Adem; Erturan, Zayre; Somer, Ayper

2016-10-01

The purpose of this study was to establish species distribution of Candida isolates from pediatric patients in Istanbul, Turkey, and to determine risk factors associated with nosocomial Candida infections. This study was conducted between June 2013 and June 2014 by participation of 7 medical centers in Istanbul. Candida spp strains isolated from the clinical specimens of pediatric patients were included. Clinical features were recorded on a standardized data collection sheet. A total of 134 systemic Candida infections were identified in 134 patients. The patients were admitted in pediatric and neonatal intensive care units (41.8% and 9.7%, respectively) and in pediatric wards (48.5%). Candida albicans was the most prevalent species (47%), followed by Candida parapsilosis (13.4%), Candida tropicalis (8.2%), Candida glabrata (4.5%), Candida lusitaniae (3.7%), Candida kefyr (2.2%), Candida guilliermondii (1.5%), Candida dubliniensis (0.7%), and Candida krusei (0.7%). Types of Candida infections were candidemia (50.7%), urinary tract infection (33.6%), surgical site infection (4.5%), central nervous system infection (3.7%), catheter infection (3.7%), and intra-abdominal infection (3.7%). In multivariate analysis, younger age (1-24 months) and detection of non-albicans Candida spp was found to be risk factors associated with candidemia (P = 0.040; odds ratio [OR], 4.1; 95% confidence interval [CI], 1.06-15.86; and P = 0.02; OR, 2.4; 95% CI, 1.10-5.53, respectively). This study provides an update for the epidemiology of nosocomial Candida infections in Istanbul, which is important for the management of patients and implementation of appropriate infection control measures. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Fungi that Infect Humans.

PubMed

Köhler, Julia R; Hube, Bernhard; Puccia, Rosana; Casadevall, Arturo; Perfect, John R

2017-06-01

Fungi must meet four criteria to infect humans: growth at human body temperatures, circumvention or penetration of surface barriers, lysis and absorption of tissue, and resistance to immune defenses, including elevated body temperatures. Morphogenesis between small round, detachable cells and long, connected cells is the mechanism by which fungi solve problems of locomotion around or through host barriers. Secretion of lytic enzymes, and uptake systems for the released nutrients, are necessary if a fungus is to nutritionally utilize human tissue. Last, the potent human immune system evolved in the interaction with potential fungal pathogens, so few fungi meet all four conditions for a healthy human host. Paradoxically, the advances of modern medicine have made millions of people newly susceptible to fungal infections by disrupting immune defenses. This article explores how different members of four fungal phyla use different strategies to fulfill the four criteria to infect humans: the Entomophthorales, the Mucorales, the Ascomycota, and the Basidiomycota. Unique traits confer human pathogenic potential on various important members of these phyla: pathogenic Onygenales comprising thermal dimorphs such as Histoplasma and Coccidioides ; the Cryptococcus spp. that infect immunocompromised as well as healthy humans; and important pathogens of immunocompromised patients- Candida , Pneumocystis , and Aspergillus spp. Also discussed are agents of neglected tropical diseases important in global health such as mycetoma and paracoccidiomycosis and common pathogens rarely implicated in serious illness such as dermatophytes. Commensalism is considered, as well as parasitism, in shaping genomes and physiological systems of hosts and fungi during evolution.

Broad-Range Detection of Microorganisms Directly from Bronchoalveolar Lavage Specimens by PCR/Electrospray Ionization-Mass Spectrometry

PubMed Central

Ullberg, Måns; Lüthje, Petra; Mölling, Paula; Strålin, Kristoffer

2017-01-01

The clinical demand on rapid microbiological diagnostic is constantly increasing. PCR coupled to electrospray ionization-mass spectrometry, PCR/ESI-MS, offers detection and identification of over 750 bacteria and Candida species directly from clinical specimens within 6 hours. In this study, we investigated the clinical performance of the IRIDICA BAC LRT Assay for detection of bacterial pathogens in 121 bronchoalveolar lavage (BAL) samples that were received consecutively at our bacterial laboratory for BAL culture. Commensal or pathogenic microorganisms were detected in 118/121 (98%) BAL samples by PCR/ESI-MS, while in 104/121 (86%) samples by routine culture (P<0.01). Detection of potentially pathogenic microorganisms by PCR/ESI-MS was evaluated in comparison with conventional culture-based or molecular methods. The agreement between positive findings was overall good. Most Staphylococcus aureus-positive PCR/ESI-MS results were confirmed by culture or species-specific PCR (27/33, 82%). The identity of Streptococcus pneumoniae could however be confirmed for only 6/17 (35%) PCR/ESI-MS-positive samples. Non-cultivable and fastidious pathogens, which were not covered by standard culture procedures were readily detected by PCR/ESI-MS, including Legionella pneumophila, Bordetella pertussis, Norcadia species and Mycoplasma pneumoniae. In conclusion, PCR/ESI-MS detected a broad range of potential pathogens with equal or superior sensitivity compared to conventional methods within few hours directly from BAL samples. This novel method might thus provide a relevant tool for diagnostics in critically ill patients. PMID:28085931

Antibody to a conserved antigenic target is protective against diverse prokaryotic and eukaryotic pathogens

PubMed Central

Cywes-Bentley, Colette; Skurnik, David; Zaidi, Tanweer; Roux, Damien; DeOliveira, Rosane B.; Garrett, Wendy S.; Lu, Xi; O’Malley, Jennifer; Kinzel, Kathryn; Zaidi, Tauqeer; Rey, Astrid; Perrin, Christophe; Fichorova, Raina N.; Kayatani, Alexander K. K.; Maira-Litràn, Tomas; Gening, Marina L.; Tsvetkov, Yury E.; Nifantiev, Nikolay E.; Bakaletz, Lauren O.; Pelton, Stephen I.; Golenbock, Douglas T.; Pier, Gerald B.

2013-01-01

Microbial capsular antigens are effective vaccines but are chemically and immunologically diverse, resulting in a major barrier to their use against multiple pathogens. A β-(1→6)–linked poly-N-acetyl-d-glucosamine (PNAG) surface capsule is synthesized by four proteins encoded in genetic loci designated intercellular adhesion in Staphylococcus aureus or polyglucosamine in selected Gram-negative bacterial pathogens. We report that many microbial pathogens lacking an identifiable intercellular adhesion or polyglucosamine locus produce PNAG, including Gram-positive, Gram-negative, and fungal pathogens, as well as protozoa, e.g., Trichomonas vaginalis, Plasmodium berghei, and sporozoites and blood-stage forms of Plasmodium falciparum. Natural antibody to PNAG is common in humans and animals and binds primarily to the highly acetylated glycoform of PNAG but is not protective against infection due to lack of deposition of complement opsonins. Polyclonal animal antibody raised to deacetylated glycoforms of PNAG and a fully human IgG1 monoclonal antibody that both bind to native and deacetylated glycoforms of PNAG mediated complement-dependent opsonic or bactericidal killing and protected mice against local and/or systemic infections by Streptococcus pyogenes, Streptococcus pneumoniae, Listeria monocytogenes, Neisseria meningitidis serogroup B, Candida albicans, and P. berghei ANKA, and against colonic pathology in a model of infectious colitis. PNAG is also a capsular polysaccharide for Neisseria gonorrhoeae and nontypable Hemophilus influenzae, and protects cells from environmental stress. Vaccination targeting PNAG could contribute to immunity against serious and diverse prokaryotic and eukaryotic pathogens, and the conserved production of PNAG suggests that it is a critical factor in microbial biology. PMID:23716675

Cross-feeding and interkingdom communication in dual-species biofilms of Streptococcus mutans and Candida albicans

PubMed Central

Sztajer, Helena; Szafranski, Szymon P; Tomasch, Jürgen; Reck, Michael; Nimtz, Manfred; Rohde, Manfred; Wagner-Döbler, Irene

2014-01-01

Polymicrobial biofilms are of large medical importance, but relatively little is known about the role of interspecies interactions for their physiology and virulence. Here, we studied two human pathogens co-occuring in the oral cavity, the opportunistic fungus Candida albicans and the caries-promoting bacterium Streptococcus mutans. Dual-species biofilms reached higher biomass and cell numbers than mono-species biofilms, and the production of extracellular polymeric substances (EPSs) by S. mutans was strongly suppressed, which was confirmed by scanning electron microscopy, gas chromatography–mass spectrometry and transcriptome analysis. To detect interkingdom communication, C. albicans was co-cultivated with a strain of S. mutans carrying a transcriptional fusion between a green fluorescent protein-encoding gene and the promoter for sigX, the alternative sigma factor of S. mutans, which is induced by quorum sensing signals. Strong induction of sigX was observed in dual-species biofilms, but not in single-species biofilms. Conditioned media from mixed biofilms but not from C. albicans or S. mutans cultivated alone activated sigX in the reporter strain. Deletion of comS encoding the synthesis of the sigX-inducing peptide precursor abolished this activity, whereas deletion of comC encoding the competence-stimulating peptide precursor had no effect. Transcriptome analysis of S. mutans confirmed induction of comS, sigX, bacteriocins and the downstream late competence genes, including fratricins, in dual-species biofilms. We show here for the first time the stimulation of the complete quorum sensing system of S. mutans by a species from another kingdom, namely the fungus C. albicans, resulting in fundamentally changed virulence properties of the caries pathogen. PMID:24824668

Effective killing of the human pathogen Candida albicans by a specific inhibitor of non-essential mitotic kinesin Kip1p

PubMed Central

Chua, Penelope R; Roof, David M; Lee, Yan; Sakowicz, Roman; Clarke, David; Pierce, Dan; Stephens, Thoryn; Hamilton, Matthew; Morgan, Brad; Morgans, David; Nakai, Takashi; Tomasi, Adam; Maxon, Mary E

2007-01-01

Kinesins from the bipolar (Kinesin-5) family are conserved in eukaryotic organisms and play critical roles during the earliest stages of mitosis to mediate spindle pole body separation and formation of a bipolar mitotic spindle. To date, genes encoding bipolar kinesins have been reported to be essential in all organisms studied. We report the characterization of CaKip1p, the sole member of this family in the human pathogenic yeast Candida albicans. C. albicans Kip1p appears to localize to the mitotic spindle and loss of CaKip1p function interferes with normal progression through mitosis. Inducible excision of CaKIP1 revealed phenotypes unique to C. albicans, including viable homozygous Cakip1 mutants and an aberrant spindle morphology in which multiple spindle poles accumulate in close proximity to each other. Expression of the C. albicans Kip1 motor domain in Escherichia coli produced a protein with microtubule-stimulated ATPase activity that was inhibited by an aminobenzothiazole (ABT) compound in an ATP-competitive fashion. This inhibition results in ‘rigor-like’, tight association with microtubules in vitro. Upon treatment of C. albicans cells with the ABT compound, cells were killed, and terminal phenotype analysis revealed an aberrant spindle morphology similar to that induced by loss of the CaKIP1 gene. The ABT compound discovered is the first example of a fungal spindle inhibitor targeted to a mitotic kinesin. Our results also show that the non-essential nature and implementation of the bipolar motor in C. albicans differs from that seen in other organisms, and suggest that inhibitors of a non-essential mitotic kinesin may offer promise as cidal agents for antifungal drug discovery. PMID:17573815

Performance of two MALDI-TOF MS systems for the identification of yeasts isolated from bloodstream infections and cerebrospinal fluids using a time-saving direct transfer protocol.

PubMed

Hamprecht, Axel; Christ, Sara; Oestreicher, Tanja; Plum, Georg; Kempf, Volkhard A J; Göttig, Stephan

2014-04-01

The rapid and correct identification of pathogens is of paramount importance for the treatment of patients with invasive infections. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) can speed up the identification of bacteria and fungi and has quickly been embraced by medical microbiology laboratories worldwide. Different MALDI-TOF systems have been compared in studies focussing on identification rates of different pathogens. Another aspect that has not been systematically assessed is the performance in daily routine and handling, which is important especially for microbiology routine laboratories. We compared two widespread commercial systems, Microflex LT Biotyper (Bruker) and VitekMS (bioMérieux), for the identification of 210 relevant clinical yeasts under routine conditions, using a time-saving direct transfer protocol. We assessed the need for an additional extraction step, the threshold for species identification and the duration of measurements with the two systems. The tested yeasts included 34 Candida albicans isolates, 144 non-albicans Candida spp. and 32 yeasts of different genera. The results of the two MS systems were compared with that of biochemical identification and, in case of discrepancies, DNA sequencing of the internal transcribed spacer or the large subunit of ribosomal DNA. Both systems correctly identified 96.2 % of isolates [202/210, non-significant (n.s.)]. Misidentifications were observed for VitekMS only (n = 5, no major errors, n.s.). VitekMS was the slower system (19.8 vs. 8.0 min for 10 samples, p = 0.002) but had the advantage of a more effective direct transfer protocol with less need for an additional extraction step.