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Sample records for albicans candida spp

  1. Detection of Salmonella spp., Candida albicans, Aspergillus spp., and Antimicrobial Residues in Raw and Processed Cow Milk from Selected Smallholder Farms of Zimbabwe

    PubMed Central

    Mhone, Tryness Anastazia; Matope, Gift; Saidi, Petronella Tapiwa

    2012-01-01

    A cross-sectional study was conducted to detect the presence of Salmonella spp., Candida albicans, Aspergillus spp., and antimicrobial residues in raw milk (n = 120) and processed cow milk (n = 20) from smallholder dairy farms from three sites in Zimbabwe. Culture and isolation of Salmonella spp., C. albicans, and Aspergillus spp. were performed using selective media, while antimicrobial residues were detected by a dye reduction test. No Salmonella, but C. albicans (17.5%; 21/120), Aspergillus spp. (0.8%; 1/120), and antimicrobial residues (2.5%; 3/120) were detected from raw milk. C. albicans was isolated from all three sites, while Aspergillus spp. and antimicrobial residues were detected from sites 1 and 3, respectively. From processed milk, only C. albicans (5%) was isolated while Aspergillus spp. and antimicrobial residues were not detected. These results suggested low prevalence of Salmonella spp. and Aspergillus spp. and a relatively high prevalence of C. albicans in raw milk from the smallholder farms. The potential public health risks of C. albicans and the detected antimicrobial residues need to be considered. Thus, educating farmers on improving milking hygiene and storage of milk and establishing programmes for monitoring antimicrobial residues may help to improve the safety of milk from smallholder farms. PMID:23050199

  2. Genetics of Candida albicans.

    PubMed Central

    Scherer, S; Magee, P T

    1990-01-01

    Candida albicans is among the most common fungal pathogens. Infections caused by C. albicans and other Candida species can be life threatening in individuals with impaired immune function. Genetic analysis of C. albicans pathogenesis is complicated by the diploid nature of the species and the absence of a known sexual cycle. Through a combination of parasexual techniques and molecular approaches, an effective genetic system has been developed. The close relationship of C. albicans to the more extensively studied Saccharomyces cerevisiae has been of great utility in the isolation of Candida genes and development of the C. albicans DNA transformation system. Molecular methods have been used for clarification of taxonomic relationships and more precise epidemiologic investigations. Analysis of the physical and genetic maps of C. albicans and the closely related Candida stellatoidea has provided much information on the highly fluid nature of the Candida genome. The genetic system is seeing increased application to biological questions such as drug resistance, virulence determinants, and the phenomenon of phenotypic variation. Although most molecular analysis to data has been with C. albicans, the same methodologies are proving highly effective with other Candida species. Images PMID:2215421

  3. Non-albicans Candida Infection: An Emerging Threat

    PubMed Central

    Deorukhkar, Sachin C.; Saini, Santosh

    2014-01-01

    The very nature of infectious diseases has undergone profound changes in the past few decades. Fungi once considered as nonpathogenic or less virulent are now recognized as a primary cause of morbidity and mortality in immunocompromised and severely ill patients. Candida spp. are among the most common fungal pathogens. Candida albicans was the predominant cause of candidiasis. However, a shift toward non-albicans Candida species has been recently observed. These non-albicans Candida species demonstrate reduced susceptibility to commonly used antifungal drugs. In the present study, we investigated the prevalence of non-albicans Candida spp. among Candida isolates from various clinical specimens and analysed their virulence factors and antifungal susceptibility profile. A total of 523 Candida spp. were isolated from various clinical specimens. Non-albicans Candida species were the predominant pathogens isolated. Non-albicans Candida species also demonstrated the production of virulence factors once attributed to Candida albicans. Non-albicans Candida demonstrated high resistance to azole group of antifungal agents. Therefore, it can be concluded that non-albicans Candida species have emerged as an important cause of infections. Their isolation from clinical specimen can no longer be ignored as a nonpathogenic isolate nor can it be dismissed as a contaminant. PMID:25404942

  4. Candida albicans clades.

    PubMed

    Soll, David R; Pujol, Claude

    2003-10-24

    DNA fingerprinting with the complex probe Ca3 has revealed the following five Candida albicans clades: group I, group II, group III, group SA and group E. These groups exhibit geographical specificity. Group SA is relatively specific (i.e., highly enriched) to South Africa, group E is relatively specific to Europe, and group II is absent in the Southwest USA and South America. The maintenance of deep-rooted clades side by side in the same geographical locale and the apparent absence of subclade structure suggest little recombination between clades, but higher rates of recombination within clades. Exclusive 5-fluorocytosine resistance in the majority of group I isolates reinforces the above conclusions on recombination, and demonstrates that clades differ phenotypically. The ramifications of these findings with regard to pathogenesis are discussed. In particular, these findings lay to rest the idea that one strain represents all strains of C. albicans, support the need for a worldwide analysis of population structure and clade-specific phenotypic characteristics, and demonstrate that in the future, pathogenic characteristics must be analyzed in representatives from all five clades. PMID:14556989

  5. Synergy of CAY-1, a Fungicidal Saponin, With Amphotericin B and Itreconazole Against Aspergillus spp and Candida albicans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: CAY-1 (mol.wt. 1243), a fungicidal saponin in cayenne (Capsicum fruitescens) is highly lethal for Aspergillus species, Candida albicans, and Pneumocystis carinii below 24.8 ug/ml. To further characterize CAY-1, synergy studies with amphotericin B (AMB) and itraconazole (IT) were perform...

  6. The novel azole R126638 is a selective inhibitor of ergosterol synthesis in Candida albicans, Trichophyton spp., and Microsporum canis.

    PubMed

    Vanden Bossche, Hugo; Ausma, Jannie; Bohets, Hilde; Vermuyten, Karen; Willemsens, Gustaaf; Marichal, Patrick; Meerpoel, Lieven; Odds, Frank; Borgers, Marcel

    2004-09-01

    R126638 is a novel triazole with in vitro activity similar to that of itraconazole against dermatophytes, Candida spp., and Malassezia spp. In animal models of dermatophyte infections, R126638 showed superior antifungal activity. R126638 inhibits ergosterol synthesis in Candida albicans, Trichophyton mentagrophytes, Trichophyton rubrum, and Microsporum canis at nanomolar concentrations, with 50% inhibitory concentrations (IC(50)s) similar to those of itraconazole. The decreased synthesis of ergosterol and the concomitant accumulation of 14 alpha-methylsterols provide indirect evidence that R126638 inhibits the activity of CYP51 that catalyzes the oxidative removal of the 14 alpha-methyl group of lanosterol or eburicol. The IC(50)s for cholesterol synthesis from acetate in human hepatoma cells were 1.4 microM for itraconazole and 3.1 microM for R126638. Compared to itraconazole (IC(50) = 3.5 microM), R126638 is a poor inhibitor of the 1 alpha-hydroxylation of 25-hydroxyvitamin D(3) (IC(50) > 10 microM). Micromolar concentrations of R126638 and itraconazole inhibited the 24-hydroxylation of 25-hydroxyvitamin D(3) and the conversion of 1,25-dihydroxyvitamin D(3) into polar metabolites. At concentrations up to 10 microM, R126638 had almost no effect on cholesterol side chain cleavage (CYP11A1), 11 beta-hydroxylase (CYP11B1), 17-hydroxylase and 17,20-lyase (CYP17), aromatase (CYP19), or 4-hydroxylation of all-trans retinoic acid (CYP26). At 10 microM, R126638 did not show clear inhibition of CYP1A2, CYP2A6, CYP2D6, CYP2C8, CYP2C9, CYP2C10, CYP2C19, or CYP2E1. Compared to itraconazole, R126638 had a lower interaction potential with testosterone 6 beta hydroxylation and cyclosporine hydroxylation, both of which are catalyzed by CYP3A4, whereas both antifungals inhibited the CYP3A4-catalyzed hydroxylation of midazolam similarly. The results suggest that R126638 has promising properties and merits further in vivo investigations for the treatment of dermatophyte and yeast

  7. Skin Immunity to Candida albicans.

    PubMed

    Kashem, Sakeen W; Kaplan, Daniel H

    2016-07-01

    Candida albicans is a dimorphic commensal fungus that colonizes healthy human skin, mucosa, and the reproductive tract. C. albicans is also a predominantly opportunistic fungal pathogen, leading to disease manifestations such as disseminated candidiasis and chronic mucocutaneous candidiasis (CMC). The differing host susceptibilities for the sites of C. albicans infection have revealed tissue compartmentalization with tailoring of immune responses based on the site of infection. Furthermore, extensive studies of host genetics in rare cases of CMC have identified conserved genetic pathways involved in immune recognition and the response to the extracellular pathogen. We focus here on human and mouse skin as a site of C. albicans infection, and we review established and newly discovered insights into the cellular pathways that promote cutaneous antifungal immunity. PMID:27178391

  8. Candida albicans, plasticity and pathogenesis.

    PubMed

    Poulain, Daniel

    2015-06-01

    The yeast Candida albicans has emerged as a major public health problem during the past two decades. The spectrum of diseases caused by this species ranges from vaginal infections, which affect up to 75% of the women at least once in their lifetime, to deep infections in hospitalized patients which lead to high morbidity and mortality rates. Candida albicans may also play a role in the persistence or worsening of some chronic inflammatory bowel diseases. Active research is now improving our understanding of the molecular mechanisms and genetic factors in the yeast and its host which influence the development of disease. Despite these advances and the availability of a more extensive therapeutic arsenal, current progress in the control of nosocomial infections due to Candida remains limited, mainly due to the difficulties in diagnosing these infections. The biologist has a key role to play in establishing a dialogue with the clinician in order to identify the saprophyte/pathogen transition in patients as early as possible. This review provides a quick synopsis of the modern concepts of Candida pathogenesis with some representative examples illustrating the specifics traits of this yeast in terms of pathogenic adaptation. PMID:23962107

  9. Growth inhibition and ultrastructural alterations induced by Δ24(25)-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms

    PubMed Central

    2009-01-01

    Background Although Candida species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment. The purpose of this study was to evaluate the antifungal activity of inhibitors of Δ24(25)-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5α-pregnan-3β-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of Candida spp., analysing the ultrastructural changes. Results AZA and EIL were found to be potent growth inhibitors of Candida spp. isolates. The median MIC50 was 0.5 μg.ml-1 for AZA and 2 μg.ml-1 for EIL, and the MIC90 was 2 μg.ml-1 for both compounds. All strains used in this study were susceptible to amphotericin B; however, some isolates were fluconazole- and itraconazole-resistant. Most of the azole-resistant isolates were Candida non-albicans (CNA) species, but several of them, such as C. guilliermondii, C. zeylanoides, and C. lipolytica, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain C. krusei (ATCC 6258, FLC-resistant) was consistently susceptible to AZA, although not to EIL. The fungicidal activity of 24-SMTI was particularly high against CNA isolates. Treatment with sub-inhibitory concentrations of AZA and EIL induced several ultrastructural alterations, including changes in the cell-wall shape and thickness, a pronounced disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, mitochondrial swelling, and the presence of electron-dense vacuoles. Fluorescence microscopy analyses indicated an accumulation of lipid bodies and alterations in the cell cycle of the yeasts. The selectivity of 24-SMTI for fungal cells versus mammalian cells was assessed by the sulforhodamine B viability assay. Conclusion Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control Candida spp. infections, including those caused by azole

  10. Candida albicans commensalism in the gastrointestinal tract.

    PubMed

    Neville, B Anne; d'Enfert, Christophe; Bougnoux, Marie-Elisabeth

    2015-11-01

    Candida albicans is a polymorphic yeast species that often forms part of the commensal gastrointestinal mycobiota of healthy humans. It is also an important opportunistic pathogen. A tripartite interaction involving C. albicans, the resident microbiota and host immunity maintains C. albicans in its commensal form. The influence of each of these factors on C. albicans carriage is considered herein, with particular focus on the mycobiota and the approaches used to study it, models of gastrointestinal colonization by C. albicans, the C. albicans genes and phenotypes that are necessary for commensalism and the host factors that influence C. albicans carriage. PMID:26347504

  11. Urinary tract infections and Candida albicans

    PubMed Central

    Behzadi, Payam; Behzadi, Elham

    2015-01-01

    Introduction 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. Material and methods 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. Results 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. Conclusions 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. PMID:25914847

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

    PubMed

    Whibley, Natasha; Gaffen, Sarah L

    2015-11-01

    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 Candida 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

  13. GENETIC CONTROL OF CANDIDA ALBICANS BIOFILM DEVELOPMENT

    PubMed Central

    Finkel, Jonathan S.; Mitchell, Aaron P.

    2014-01-01

    Preface Candida species cause frequent infections due to their ability to form biofilms – surface-associated microbial communities – primarily on implanted medical devices. Increasingly, mechanistic studies have identified the gene products that participate directly in Candida albicans biofilm formation, as well as the regulatory circuitry and networks that control their expression and activity. These studies have revealed new mechanisms and signals that govern C. albicans biofilm formation and associated drug resistance, thus providing biological insight and therapeutic foresight. PMID:21189476

  14. Candida glabrata among Candida spp. from environmental health practitioners of a Brazilian Hospital.

    PubMed

    Savastano, Catarina; de Oliveira Silva, Elisa; Gonçalves, Lindyanne Lemos; Nery, Jéssica Maria; Silva, Naiara Chaves; Dias, Amanda Latercia Tranches

    2016-01-01

    The incidence of the species Candida albicans and non-albicans Candida was evaluated in a Brazilian Tertiary Hospital from the environment and health practitioners. In a 12-month period we had a total positivity of 19.65% of Candida spp. The most recurring non-albicans Candida species was C. glabrata (37.62%), generally considered a species of low virulence, but with a higher mortality rate than C. albicans. Subsequently, C. parapsilosis (25.74%) and C. tropicalis (16.86%) were the second and third most commonly isolated species. Considering the total samples collected from the emergency room and from the inpatient and the pediatric sector, 19.10% were positive for Candida spp., with the predominance of non-albicans Candida species (89.42%). The high percentage of positivity occurred in the hands (24.32%) and the lab coats (21.88%) of the health care assistants. No sample of C. albicans presented a profile of resistance to the drugs. All the non-albicans Candida species presented a decreased susceptibility to miconazole and itraconazole, but they were susceptible to nystatin. Most of the isolates were susceptible to fluconazole and amphotericin B. As expected, a high resistance rate was observed in C. glabrata and C. krusei, which are intrinsically less susceptible to this antifungal agent. The contamination of environmental surfaces by Candida spp. through hand touching may facilitate the occurrence of Candida infections predominantly in immunocompromised patients. In addition to that, the antifungal agents used should be carefully evaluated considering local epidemiologic trends in Candida spp. infections, so that therapeutic choices may be better guided. PMID:26991302

  15. Candida/Candida biofilms. First description of dual-species Candida albicans/C. rugosa biofilm.

    PubMed

    Martins, Carlos Henrique Gomes; Pires, Regina Helena; Cunha, Aline Oliveira; Pereira, Cristiane Aparecida Martins; Singulani, Junya de Lacorte; Abrão, Fariza; Moraes, Thais de; Mendes-Giannini, Maria José Soares

    2016-04-01

    Denture liners have physical properties that favour plaque accumulation and colonization by Candida species, irritating oral tissues and causing denture stomatitis. To isolate and determine the incidence of oral Candida species in dental prostheses, oral swabs were collected from the dental prostheses of 66 patients. All the strains were screened for their ability to form biofilms; both monospecies and dual-species combinations were tested. Candida albicans (63 %) was the most frequently isolated microorganism; Candida tropicalis (14 %), Candida glabrata (13 %), Candida rugosa (5 %), Candida parapsilosis (3 %), and Candida krusei (2 %) were also detected. The XTT assay showed that C. albicans SC5314 possessed a biofilm-forming ability significantly higher (p < 0.001) than non-albicans Candida strains, after 6 h 37 °C. The total C. albicans CFU from a dual-species biofilm was less than the total CFU of a monospecies C. albicans biofilm. In contrast to the profuse hyphae verified in monospecies C. albicans biofilms, micrographies showed that the C. albicans/non-albicans Candida biofilms consisted of sparse yeast forms and profuse budding yeast cells that generated a network. These results suggested that C. albicans and the tested Candida species could co-exist in biofilms displaying apparent antagonism. The study provide the first description of C. albicans/C. rugosa mixed biofilm. PMID:27020154

  16. Development of DNA probes for Candida albicans

    SciTech Connect

    Cheung, L.L.; Hudson, J.B.

    1988-07-01

    An attempt was made to produce DNA probes that could be used as a rapid and efficient means of detecting candidiasis (invasive Candida infection) in immunocompromised patients. Whole DNA from Candida albicans was digested with restriction endonuclease, and the resulting fragments were randomly cloned into a plasmid vector. Several recombinant plasmids were evaluated for cross-hybridization to various other Candida species, other fungal DNAs, and to nonfungal DNAs. Cross reactions were observed between the probes and different yeasts, but none with unrelated DNAs. Some recombinants were genus-specific, and two of these were applied to the analysis of C. albicans growth curves. It became evident that, although both /sup 32/P- and biotin-labelled probes could be made quite sensitive, a possible limitation in their diagnostic potential was the poor liberation of Candida DNA from cells. Thus, better methods of treatment of clinical specimens will be required before such probes will be useful in routine diagnosis.

  17. Endothelial Cell Stimulation by Candida albicans

    PubMed Central

    Phan, Quynh T.; Filler, Scott G.

    2013-01-01

    The opportunistic fungal pathogen, Candida albicans, enters the bloodstream and causes hematogenously disseminated infection in hospitalized patients. During the initiation of a hematogenously disseminated infection, endothelial cells are one of the first host cells to come in contact with C. albicans. Endothelial cells can significantly influence the local host response to C. albicans by expressing leukocyte adhesion molecules and pro-inflammatory cytokines. Thus, it is of interest to investigate the response of endothelial cells to C. albicans in vitro. We describe the use of real-time PCR and enzyme immunoassays to measure the effects of C. albicans on the endothelial cell production of E-selectin and tumor necrosis factor α in vitro. PMID:19089392

  18. Mucosal biofilms of Candida albicans.

    PubMed

    Ganguly, Shantanu; Mitchell, Aaron P

    2011-08-01

    Biofilms are microbial communities that form on surfaces and are embedded in an extracellular matrix. C. albicans forms pathogenic mucosal biofilms that are evoked by changes in host immunity or mucosal ecology. Mucosal surfaces are inhabited by many microbial species; hence these biofilms are polymicrobial. Several recent studies have applied paradigms of biofilm analysis to study mucosal C. albicans infections. These studies reveal that the Bcr1 transcription factor is a master regulator of C. albicans biofilm formation under diverse conditions, though the most relevant Bcr1 target genes can vary with the biofilm niche. An important determinant of mucosal biofilm formation is the interaction with host defenses. Finally, studies of interactions between bacterial species and C. albicans provide insight into the communication mechanisms that endow polymicrobial biofilms with unique properties. PMID:21741878

  19. Mucins Suppress Virulence Traits of Candida albicans

    PubMed Central

    Kavanaugh, Nicole L.; Zhang, Angela Q.; Nobile, Clarissa J.; Johnson, Alexander D.

    2014-01-01

    ABSTRACT Candida albicans is the most prevalent fungal pathogen of humans, causing a variety of diseases ranging from superficial mucosal infections to deep-seated systemic invasions. Mucus, the gel that coats all wet epithelial surfaces, accommodates C. albicans as part of the normal microbiota, where C. albicans resides asymptomatically in healthy humans. Through a series of in vitro experiments combined with gene expression analysis, we show that mucin biopolymers, the main gel-forming constituents of mucus, induce a new oval-shaped morphology in C. albicans in which a range of genes related to adhesion, filamentation, and biofilm formation are downregulated. We also show that corresponding traits are suppressed, rendering C. albicans impaired in forming biofilms on a range of different synthetic surfaces and human epithelial cells. Our data suggest that mucins can manipulate C. albicans physiology, and we hypothesize that they are key environmental signals for retaining C. albicans in the host-compatible, commensal state. PMID:25389175

  20. Molecular Epidemiology of Candida albicans and Its Closely Related Yeasts Candida dubliniensis and Candida africana▿

    PubMed Central

    Romeo, Orazio; Criseo, Giuseppe

    2009-01-01

    We performed a molecular study to determine the occurrence of Candida albicans, Candida africana, and Candida dubliniensis in different clinical samples. The study provides new insights into the epidemiology of candidiasis in hospitalized patients in three hospitals in southern Italy. It also reports the first detailed epidemiological data concerning the occurrence of C. africana in clinical samples. PMID:18987171

  1. Molecular epidemiology of Candida albicans and its closely related yeasts Candida dubliniensis and Candida africana.

    PubMed

    Romeo, Orazio; Criseo, Giuseppe

    2009-01-01

    We performed a molecular study to determine the occurrence of Candida albicans, Candida africana, and Candida dubliniensis in different clinical samples. The study provides new insights into the epidemiology of candidiasis in hospitalized patients in three hospitals in southern Italy. It also reports the first detailed epidemiological data concerning the occurrence of C. africana in clinical samples. PMID:18987171

  2. Candida albicans Biofilms and Human Disease

    PubMed Central

    Nobile, Clarissa J.; Johnson, Alexander D.

    2016-01-01

    In humans, microbial cells (including bacteria, archaea, and fungi) greatly outnumber host cells. Candida albicans is the most prevalent fungal species of the human microbiota; this species asymptomatically colonizes many areas of the body, particularly the gastrointestinal and genitourinary tracts of healthy individuals. Alterations in host immunity, stress, resident microbiota, and other factors can lead to C. albicans overgrowth, causing a wide range of infections, from superficial mucosal to hematogenously disseminated candidiasis. To date, most studies of C. albicans have been carried out in suspension cultures; however, the medical impact of C. albicans (like that of many other microorganisms) depends on its ability to thrive as a biofilm, a closely packed community of cells. Biofilms are notorious for forming on implanted medical devices, including catheters, pacemakers, dentures, and prosthetic joints, which provide a surface and sanctuary for biofilm growth. C. albicans biofilms are intrinsically resistant to conventional antifungal therapeutics, the host immune system, and other environmental perturbations, making biofilm-based infections a significant clinical challenge. Here, we review our current knowledge of biofilms formed by C. albicans and closely related fungal species. PMID:26488273

  3. A Candida albicans PeptideAtlas

    PubMed Central

    Vialas, Vital; Sun, Zhi; Penha, Carla Verónica Loureiro y; Carrascal, Montserrat; Abian, Joaquin; Monteoliva, Lucía; Deutsch, Eric W.; Aebersold, Ruedi; Moritz, Robert L.; Gil, Concha

    2013-01-01

    Candida albicans public proteomic data sets, though growing steadily in the last few years, still have a very limited presence in online repositories. We report here the creation of a C. albicans PeptideAtlas comprising near 22000 distinct peptides at a 0.24 % False Discovery Rate (FDR) that account for over 2500 canonical proteins at a 1.2% FDR. Based on data from 16 experiments, we attained coverage of 41% of the C.albicans open reading frame sequences (ORFs) in the database used for the searches. This PeptideAtlas provides several useful features, including comprehensive protein and peptide-centered search capabilities and visualization tools that establish a solid basis for the study of basic biological mechanisms key to virulence and pathogenesis such as dimorphism, adherence, and apoptosis. Further, it is a valuable resource for the selection of candidate proteotypic peptides for targeted proteomic experiments via selected reaction monitoring (SRM) or SWATH-MS. PMID:23811049

  4. 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

  5. In vitro pharmacodynamic modelling of anidulafungin against Candida spp.

    PubMed

    Gil-Alonso, Sandra; Jauregizar, Nerea; Ortega, Ignacio; Eraso, Elena; Suárez, Elena; Quindós, Guillermo

    2016-03-01

    The aim of this study was to fit anidulafungin in vitro static time-kill data from nine strains of Candida with a pharmacodynamic (PD) model in order to describe the antifungal activity of this drug against Candida spp. Time-kill data from strains of Candida albicans, Candida glabrata and Candida parapsilosis clades were best fit using an adapted sigmoidal Emax model and resulted in a set of PD parameters (Emax, EC50 and Hill factor) for each fungal strain. The data were analysed with NONMEM 7. Anidulafungin was effective in a species- and concentration-dependent manner against the strains of C. glabrata and C. parapsilosis clades as observed with the EC50 estimates. Maximum killing rate constant (Emax) values were higher against C. glabrata and C. parapsilosis complex strains. In conclusion, we demonstrated that the activity of anidulafungin against Candida can be accurately described using an adapted sigmoidal Emax model. PMID:26857078

  6. Adherence and receptor relationships of Candida albicans.

    PubMed Central

    Calderone, R A; Braun, P C

    1991-01-01

    The cell surface of Candida albicans is composed of a variety of polysaccharides such as glucan, chitin, and mannan. The first two components primarily provide structure, while the mannan, often covalently linked to protein, constitutes the major antigen of the organism. Mannoproteins also have enzymatic activity (acid protease) and ligand-receptor functions. The complement receptors of C. albicans appear to be mannoproteins that are required for the adherence of the organism to endothelial cells. This is certainly true of the CR3-like protein of C. albicans. Proof that the CR3 is the Candida receptor for endothelial cells is derived from two observations. First, mutants lacking CR3 activity are less adherent in vitro and, in fact, less virulent. Second, the ligand recognized by the CR3 receptor (C3bi) as well as anti-CR3 antibodies blocks adherence of the organism to endothelial cells. The CR2 of C. albicans appears to promote the adherence of the organism to plastic substrates. Unlike the CR2 of mammalian cells, the Candida CR2 recognizes ligands containing the RGD sequence of amino acids in addition to the C3d ligand, which does not contain the RGD sequence. There is uncertainty as to whether the Candida CR2 and CR3 are, in fact, different proteins. A mannoprotein has also been described as the adhesin for epithelial cells. In this case, the receptor has a lectinlike activity and recognizes fucose- or glucosamine-containing glycoproteins of epithelial cells, depending on the strain of C. albicans. The oligosaccharide component of the receptor is probably not involved in ligand recognition and may serve to stabilize the receptor. However, the oligosaccharide factor 6 epitope of mannan may also provide adhesin activity in the recognition of epithelial cells. Mannoproteins can be extracted from cells by a number of reagents. Zymolyase, for instance, tends to remove structural mannoproteins, which contain relatively little protein and are linked to glucan. Reagents

  7. Coaggregation of Candida albicans, Actinomyces naeslundii and Streptococcus mutans is Candida albicans strain dependent.

    PubMed

    Arzmi, Mohd Hafiz; Dashper, Stuart; Catmull, Deanne; Cirillo, Nicola; Reynolds, Eric C; McCullough, Michael

    2015-08-01

    Microbial interactions are necessarily associated with the development of polymicrobial oral biofilms. The objective of this study was to determine the coaggregation of eight strains of Candida albicans with Actinomyces naeslundii and Streptococcus mutans. In autoaggregation assays, C. albicans strains were grown in RPMI-1640 and artificial saliva medium (ASM) whereas bacteria were grown in heart infusion broth. C. albicans, A. naeslundii and S. mutans were suspended to give 10(6), 10(7) and 10(8) cells mL(-1) respectively, in coaggregation buffer followed by a 1 h incubation. The absorbance difference at 620 nm (ΔAbs) between 0 h and 1 h was recorded. To study coaggregation, the same protocol was used, except combinations of microorganisms were incubated together. The mean ΔAbs% of autoaggregation of the majority of RPMI-1640-grown C. albicans was higher than in ASM grown. Coaggregation of C. albicans with A. naeslundii and/or S. mutans was variable among C. albicans strains. Scanning electron microscopy images showed that A. naeslundii and S. mutans coaggregated with C. albicans in dual- and triculture. In conclusion, the coaggregation of C. albicans, A. naeslundii and S. mutans is C. albicans strain dependent. PMID:26054855

  8. [Candida albicans endocarditis after pulmonary artery banding].

    PubMed

    Talvard, M; Paranon, S; Dulac, Y; Mansir, T; Kreitmann, B; Acar, P

    2009-08-01

    Endocarditis is uncommon in infants and is exceptionally related to Candida albicans on pulmonary banding. We report on a case in a 7-month-old infant who had pulmonary artery banding for a ventricular septal defect and who presented with candidal endocarditis. Banding was chosen because of the patient's poor trophic and unstable status, which could be risky for surgery involving extracorporeal circulation. A few weeks after the banding, the patient developed systemic Candida infection, which was treated successfully. At 7 months, cardiac failure appeared without fever or inflammatory signs. Cardiac echography showed that the banding was not protective as well as a hyperechogenic image on the pulmonary bifurcation. The angioscan showed a hypodense thrombus. Emergency surgery was performed consisting of pulmonary artery exploration, thrombectomy, and ventricular septal defect closure. The exploration showed a pulmonary artery perforation caused by the infected pseudoaneurysm and the migration of the banding into the pulmonary artery. The anatomopathologic analysis of the vegetation identified multisensitive Candida albicans. After surgery and prolonged antifungal treatment, progression was satisfactory. PMID:19525096

  9. Farnesol-induced apoptosis in Candida albicans.

    PubMed

    Shirtliff, Mark E; Krom, Bastiaan P; Meijering, Roelien A M; Peters, Brian M; Zhu, Jingsong; Scheper, Mark A; Harris, Megan L; Jabra-Rizk, Mary Ann

    2009-06-01

    Farnesol, a precursor in the isoprenoid/sterol pathway, was recently identified as a quorum-sensing molecule produced by the fungal pathogen Candida albicans. Farnesol is involved in the inhibition of germination and biofilm formation by C. albicans and can be cytotoxic at certain concentrations. In addition, we have shown that farnesol can trigger apoptosis in mammalian cells via the classical apoptotic pathways. In order to elucidate the mechanism behind farnesol cytotoxicity in C. albicans, the response to farnesol was investigated, using proteomic analysis. Global protein expression profiles demonstrated significant changes in protein expression resulting from farnesol exposure. Among the downregulated proteins were those involved in metabolism, glycolysis, protein synthesis, and mitochondrial electron transport and the respiratory chain, whereas proteins involved in folding, protection against environmental and oxidative stress, actin cytoskeleton reorganization, and apoptosis were upregulated. Cellular changes that accompany apoptosis (regulated cell death) were further analyzed using fluorescent microscopy and gene expression analysis. The results indicated reactive oxygen species accumulation, mitochondrial degradation, and positive terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) in the farnesol-exposed cells concurrent with increased expression of antioxidant-encoding and drug response genes. More importantly, the results demonstrated farnesol-induced upregulation of the caspase gene MCA1 and the intracellular presence of activated caspases. In conclusion, this study demonstrated that farnesol promotes apoptosis in C. albicans through caspase activation, implying an important physiological role for farnesol in the fungal cell life cycle with important implications for adaptation and survival. PMID:19364863

  10. Effect of Tetrandrine against Candida albicans Biofilms

    PubMed Central

    Zhao, Lan-Xue; Li, De-Dong; Hu, Dan-Dan; Hu, Gan-Hai; Yan, Lan; Wang, Yan; Jiang, Yuan-Ying

    2013-01-01

    Candida albicans is the most common human fungal pathogen and has a high propensity to develop biofilms that are resistant to traditional antifungal agents. In this study, we investigated the effect of tetrandrine (TET) on growth, biofilm formation and yeast-to-hypha transition of C. albicans. We characterized the inhibitory effect of TET on hyphal growth and addressed its possible mechanism of action. Treatment of TET at a low concentration without affecting fungal growth inhibited hyphal growth in both liquid and solid Spider media. Real-time RT-PCR revealed that TET down-regulated the expression of hypha-specific genes ECE1, ALS3 and HWP1, and abrogated the induction of EFG1 and RAS1, regulators of hyphal growth. Addition of cAMP restored the normal phenotype of the SC5314 strain. These results indicate that TET may inhibit hyphal growth through the Ras1p-cAMP-PKA pathway. In vivo, at a range of concentrations from 4 mg/L to 32 mg/L, TET prolonged the survival of C. albicans-infected Caenorhabditis elegans significantly. This study provides useful information for the development of new strategies to reduce the incidence of C. albicans biofilm-associated infections. PMID:24260276

  11. Germination of Candida albicans induced by proline.

    PubMed Central

    Dabrowa, N; Taxer, S S; Howard, D H

    1976-01-01

    Blastospores of Candida albicans germinated in proline-biotin-buffer medium incubated at 37 C. Certain other amino acids in the glatamate, asparate, and pyruvate families also fostered germinaton but generally to a lesser extent than did proline. L-Cysteine, D-proline, and certain structural analogues of L-proline inhibited proline-stimualted germination. The concentration of phosphate and glucose was crucial to amino acid-stimulated germination of C. albicans. Clinical isolates and stock cultures varied in their response to the germ tube-inducing activity of proline or other amino acids. The proline-buffer medium cannot be used in a diagnostic test for production of germ tubes by isolates of yeasts. PMID:5375

  12. Electron Microscopy of Young Candida albicans Chlamydospores

    PubMed Central

    Miller, Sara E.; Spurlock, Ben O.; Michaels, G. E.

    1974-01-01

    One- to three-day-old cultures of Candida albicans bearing chlamydospores were grown and harvested by a special technique, free of agar, and prepared for ultramicrotomy and electron microscopy. These young chlamydospores exhibited a subcellular structure similar to that of the yeast phase, e.g., cytoplasmic membrane, ribosomes, and mitochondria. Other structural characteristics unique to chlamydospores were a very thick, layered cell wall, the outer layer of which was continuous with the outer layer of the suspensor cell wall and was covered by hair-like projections; membrane bound organelles; and large lipoid inclusions. Only young chlamydospores less than 3 to 4 days old exhibited these ultrastructural characteristics. Images PMID:4368664

  13. Candida albicans keratitis in an immunocompromised patient

    PubMed Central

    Hassan, H Mohammed J; Papanikolaou, Theocharis; Mariatos, Georgios; Hammad, Amany; Hassan, Hala

    2010-01-01

    Purpose When investigating a case of unexplained corneal ulceration, we need to think of fungal infection and any predisposing factors. Methods A case study of a corneal ulceration in a patient who was HIV positive with a devastating visual outcome. Results Therapeutic corneal graft was necessary due to corneal perforation. Immunocompromised state of patient was retrospectively diagnosed. Conclusions Candida albicans keratitis is an opportunistic infection of a compromised cornea, and sometimes unknowingly compromised host, which can be initially misdiagnosed. Despite intensive antifungal therapy, occasionally patients require corneal grafting to improve vision, and before it is possible to establish an accurate diagnosis. PMID:21060674

  14. Melittin induces apoptotic features in Candida albicans

    SciTech Connect

    Park, Cana; Lee, Dong Gun

    2010-03-26

    Melittin is a well-known antimicrobial peptide with membrane-active mechanisms. In this study, it was found that Melittin exerted its antifungal effect via apoptosis. Candida albicans exposed to Melittin showed the increased reactive oxygen species (ROS) production, measured by DHR-123 staining. Fluorescence microscopy staining with FITC-annexin V, TUNEL and DAPI further confirmed diagnostic markers of yeast apoptosis including phosphatidylserine externalization, and DNA and nuclear fragmentation. The current study suggests that Melittin possesses an antifungal effect with another mechanism promoting apoptosis.

  15. Adherence ability of Candida africana: a comparative study with Candida albicans and Candida dubliniensis.

    PubMed

    Romeo, Orazio; De Leo, Filomena; Criseo, Giuseppe

    2011-07-01

    In this study, we compared the adherence ability to human Hela cells and biofilm formation of three closely related Candida yeast. In our experiments, Candida africana showed poor adhesion ability to human Hela cells and the absence of biofilm formation on polyvinyl chloride strips. Conversely, Candida albicans and Candida dubliniensis formed mature biofilms and stable attachment to Hela cells. To our knowledge, this is the first comparative study reporting data on biofilm formation and adherence to human Hela cells by C. africana. PMID:20202113

  16. 7-hydroxycalamenene Effects on Secreted Aspartic Proteases Activity and Biofilm Formation of Candida spp.

    PubMed Central

    Azevedo, Mariana M. B.; Almeida, Catia A.; Chaves, Francisco C. M.; Rodrigues, Igor A.; Bizzo, Humberto R.; Alviano, Celuta S.; Alviano, Daniela S.

    2016-01-01

    Background: The 7-hydroxycalamenenene-rich essential oil (EO) obtained from the leaves of Croton cajucara (red morphotype) have been described as active against bacteria, protozoa, and fungi species. In this work, we aimed to evaluate the effectiveness of 7-hydroxycalamenenene against Candida albicans and nonalbicans species. Materials and Methods: C. cajucara EO was obtained by hydrodistillation and its major compound, 7-hydroxycalamenene, was purified using preparative column chromatography. The anti-candidal activity was investigated by minimum inhibitory concentration (MIC) and secreted aspartic proteases (SAP) and biofilm inhibition assays. Results: 7-hydroxycalamenene (98% purity) displayed anti-candidal activity against all Candida species tested. Higher activity was observed against Candida dubliniensis, Candida parapsilosis and Candida albicans, showing MIC values ranging from 39.06 μg/ml to 78.12 μg/ml. The purified 7-hydroxycalamenene was able to inhibit 58% of C. albicans ATCC 36801 SAP activity at MIC concentration (pH 7.0). However, 7-hydroxycalamenene demonstrated poor inhibitory activity on C. albicans ATCC 10231 biofilm formation even at the highest concentration tested (2500 μg/ml). Conclusion: The bioactive potential of 7-hydroxycalamenene against planktonic Candida spp. further supports its use for the development of antimicrobials with anti-candidal activity. SUMMARY Croton cajucara Benth. essential oil provides high amounts of 7-hydroxycalamenene7-Hydroxycalameneneisolated from C. cajucarais active against Candida spp7-Hydroxycalameneneinhibits C. albicans aspartic protease activity7-Hydroxycalamenene was not active against C. albicans biofilm formation. Figure PMID:27019560

  17. Presence of Candida spp. in the oral cavity of heart transplantation patients

    PubMed Central

    RIBEIRO, Patrícia Monteiro; BACAL, Fernando; KOGA-ITO, Cristiane Yumi; JUNQUEIRA, Juliana Campos; JORGE, Antonio Olavo Cardoso

    2011-01-01

    Candida spp. can lead to infections or even fungal sepsis particularly among immunocompromized individuals. Objective The aim of the present study was to analyze the presence of Candida spp. among patients subjected to orthotopic heart transplantation. Material and Methods Oral rinses from 50 patients subjected to orthotopic heart transplantation, aged 13 to 70 years, 40 males and 10 females, were examined. Sexage-oral conditions matched-control included 50 individuals who were not subjected to any kind of transplantation and were not immunocompromized for any other reason. Counts of yeasts were expressed as median values of logarithm of cfu/mL and were statistically compared by Mann-Whitney’s test. The heart transplant and control groups were compared for the presence of Candida spp. by chi-square test (p<0.05). Results The results showed statistically significant difference (p=0.001) in the prevalence of Candida spp. between the transplantation and control groups. Counts of yeasts (cfu/mL) in the transplanted group were significantly higher than in the control group (p=0.005). Candida albicans was the most prevalent species isolated from both groups. Conclusion It was concluded that Candida yeast counts were higher in the heart transplant recipients than in the controls. There was higher variation of Candida species among the heart transplant patients and the most frequently isolated samples were: Candida albicans, Candida glabrata and Candida tropicalis. Isolates of Candida dubliniensis was not found in either of the groups. PMID:21437462

  18. Characterization of two aminotransferases from Candida albicans.

    PubMed

    Rząd, Kamila; Gabriel, Iwona

    2015-01-01

    Aminoadipate aminotransferase (AmAA) is an enzyme of α-aminoadipate pathway (AAP) for L-lysine biosynthesis. AmAA may also participated in biosynthesis or degradation of aromatic amino acids and in D-tryptophan based pigment production. The AAP is unique for fungal microorganisms. Enzymes involved in this pathway have specific structures and properties. These features can be used as potential molecular markers. Enzymes catalyzing reactions of L-lysine biosynthesis in Candida albicans may also become new targets for antifungal chemotherapy. Search of the NCBI database resulted in identification of two putative aminoadipate aminotransferase genes from Candida albicans: ARO8 (ORFs 19.2098 and 19.9645) and YER152C (ORFs 19.1180 and 19.8771). ARO8 from C. albicans exhibits 53% identity to ARO8 from S. cerevisiae, while YER152C exhibits 30% identity to ARO8 and 45% to YER152C from S. cerevisiae. We amplified two genes from the C. albicans genome: ARO8 and YER152C. Both were cloned and expressed as His-tagged fusion proteins in E. coli. The purified Aro8CHp gene product revealed aromatic and α-aminoadipate aminotransferase activity. Basic molecular properties of the purified protein were determined. We obtained catalytic parameters of Aro8CHp with aromatic amino acids and aminoadipate (AA) (Km(L-Phe) 0.05±0.003 mM, Km(L-Tyr) 0.1±0.008 mM, Km(L-AA) 0.02±0.006 mM) and confirmed the enzyme broad substrate spectrum. The assays also demonstrated that this enzyme may use 2-oxoadipate and 2-oxoglutarate (2-OG) as amino acceptors. Aro8-CHp exhibited pH optima range of 8, which is similar to AmAA from S. cerevisiae. Our results also indicate that CaYer152Cp has a possible role only in aromatic amino acids degradation, in contrast to CaAro8CHp. PMID:26619256

  19. Interplay between the Gastric Bacterial Microbiota and Candida albicans during Postantibiotic Recolonization and Gastritis

    PubMed Central

    Mason, Katie L.; Erb Downward, John R.; Falkowski, Nicole R.; Young, Vincent B.; Kao, John Y.

    2012-01-01

    The indigenous bacterial microbiome of the stomach, including lactobacilli, is vital in promoting colonization resistance against Candida albicans. However, there are gaps in our understanding about C. albicans gastric colonization versus disease, especially during the postantibiotic recovery phase. This study compared the gastric responses to C. albicans strains CHN1 and SC5314 in microbiome-disturbed and germfree mice to elucidate the contribution of the indigenous microbiota in C. albicans colonization versus disease and yeast-bacterium antagonism during the post-cefoperazone recolonization period. C. albicans can prevent the regrowth of Lactobacillus spp. in the stomach after cefoperazone and promote increased colonization by Enterococcus spp. Using a culture-independent analysis, the effects of oral cefoperazone on the gastric bacterial microbiota were observed to last at least 3 weeks after the cessation of the antibiotic. Disturbance of the gastric bacterial community by cefoperazone alone was not sufficient to cause gastritis, C. albicans colonization was also needed. Gastritis was not evident until after day 7 in cefoperazone-treated infected mice. In contrast, in germfree mice which lack a gastric microbiota, C. albicans induced gastric inflammation within 1 week of inoculation. Therefore, the gastric bacterial community in cefoperazone-treated mice during the first week of postantibiotic recolonization was sufficient to prevent the development of gastritis, despite being ineffective at conferring colonization resistance against C. albicans. Altogether, these data implicate a dichotomy between C. albicans colonization and gastric disease that is bacterial microbiome dependent. PMID:21986629

  20. Portrait of Candida albicans Adherence Regulators

    PubMed Central

    Finkel, Jonathan S.; Xu, Wenjie; Huang, David; Hill, Elizabeth M.; Desai, Jigar V.; Woolford, Carol A.; Nett, Jeniel E.; Taff, Heather; Norice, Carmelle T.; Andes, David R.; Lanni, Frederick; Mitchell, Aaron P.

    2012-01-01

    Cell-substrate adherence is a fundamental property of microorganisms that enables them to exist in biofilms. Our study focuses on adherence of the fungal pathogen Candida albicans to one substrate, silicone, that is relevant to device-associated infection. We conducted a mutant screen with a quantitative flow-cell assay to identify thirty transcription factors that are required for adherence. We then combined nanoString gene expression profiling with functional analysis to elucidate relationships among these transcription factors, with two major goals: to extend our understanding of transcription factors previously known to govern adherence or biofilm formation, and to gain insight into the many transcription factors we identified that were relatively uncharacterized, particularly in the context of adherence or cell surface biogenesis. With regard to the first goal, we have discovered a role for biofilm regulator Bcr1 in adherence, and found that biofilm regulator Ace2 is a major functional target of chromatin remodeling factor Snf5. In addition, Bcr1 and Ace2 share several target genes, pointing to a new connection between them. With regard to the second goal, our findings reveal existence of a large regulatory network that connects eleven adherence regulators, the zinc-response regulator Zap1, and approximately one quarter of the predicted cell surface protein genes in this organism. This limited yet sensitive glimpse of mutant gene expression changes had thus defined one of the broadest cell surface regulatory networks in C. albicans. PMID:22359502

  1. Proinflammatory chemokines during Candida albicans keratitis.

    PubMed

    Yuan, Xiaoyong; Hua, Xia; Wilhelmus, Kirk R

    2010-03-01

    Chemotactic cytokines mediate the recruitment of leukocytes into infected tissues. This study investigated the profile of chemokines during experimental Candida albicans keratitis and determined the effects of chemokine inhibition on leukocyte infiltration and fungal growth during murine keratomycosis. Scarified corneas of BALB/c mice were topically inoculated with C. albicans and monitored daily over one week for fungal keratitis. After a gene microarray for murine chemokines compared infected corneas to controls, real-time reverse transcription polymerase chain reaction (RT-PCR) and immunostaining assessed chemokine expression in infected and mock-inoculated corneas. An anti-chemokine antibody was then administered subconjunctivally and evaluated for effects on clinical severity, corneal inflammation, fungal recovery, and cytokine expression. Of 33 chemokine genes examined by microarray, 6 CC chemokines and 6 CXC chemokines were significantly (P<0.05) upregulated more than two-fold. Chemokine (CC-motif) ligand 3 (CCL3) was upregulated 108-fold (P=0.03) by real-time RT-PCR within one day after fungal inoculation and remained increased 28-fold (P=0.02) at one week, and its in situ expression increased in the epithelium and stroma of infected corneas. Compared to the control antibody-treated group, eyes treated with anti-CCL3 antibody showed reduced clinical severity (P<0.05), less corneal neovascularization (P=0.02), and fewer inflammatory cells infiltrating corneal tissue, but the amount of recoverable fungi was not significantly (P=0.4) affected. Anti-CCL3 treatment significantly (P=0.01) reduced the expression of tumor necrosis factor and interleukin-1beta in infected corneas. These results indicate that chemokines, especially the CC chemokine CCL3, play important roles in the acute inflammatory response to C. albicans corneal infection. PMID:20005222

  2. Investigation of ERG11 gene expression among fluconazole-resistant Candida albicans: first report from an Iranian referral paediatric hospital.

    PubMed

    Teymuri, M; Mamishi, S; Pourakbari, B; Mahmoudi, S; Ashtiani, M T; Sadeghi, R H; Yadegari, M H

    2015-01-01

    The multiplicity of mechanisms of resistance to azole antifungal agents has been described. As fluconazole-resistant clinical Candida albicans isolates that constitutively over-express ERG11 have been identified in previous studies, the aim of this study is to investigate this molecular mechanism involved in fluconazole resistance of C. albicans clinical isolates. Fluconazole susceptibility testing was carried out on clinical isolates of Candida spp. obtained from hospitalised children in an Iranian referral children's hospital. A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique was used to differentiate Candida spp. The resistant C. albicans isolates were subjected to RT-qPCR using primers that identify ERG11 gene expression. Of the 142 Candida spp. isolates studied, C. albicans was the most predominant isolate, occurring in 68.3% (97/142) of the patients. According to the CLSI method, the majority of the C. albicans isolates (91.7%, 89/97), categorised as susceptible (minimum inhibitory concentration [MIC] ≤8 μg/mL), five isolates were considered resistant (MIC ≤64 μg/mL) and three had dose-dependent susceptibility (MIC = 8.16-32 μg/mL). The ERG11 gene in the five fluconazole-resistant C. albicans isolates was upregulated 4.15-5.84-fold relative to the ATCC 10231 control strain. In this study, the expression of ERG11 was upregulated in all the fluconazole-resistant C. albicans isolates. There are limited data on the antifungal susceptibility of Candida spp. as well as the molecular mechanism of azole resistance in Iran, especially for isolates causing infections in children. Therefore, the surveillance of antifungal resistance patterns and investigation of other mechanisms of azole resistance in all Candida spp. isolates is recommended. PMID:25906488

  3. Correlation of atherogenesis with an infection of Candida albicans

    PubMed Central

    Nurgeldiyeva, Maya J; Hojakuliyev, Bayram G; Muhammedov, Merdan B

    2014-01-01

    Purpose: To study contents of atherosclerotic plaques for the presence of fungi of the genus Candida; and an analysis of some immunological and biochemical indices in patients with acute coronary syndrome (ACS) that are positive for Candida albicans. Materials and methods: To test for the presence of fungi in an atherosclerotic plaque, we used a method developed by us (patent NO 531, a priority from 6/28/2010). A total of 47 atherosclerotic plaques were obtained during 20 autopsies. In addition, 80 individuals (58 male, 22 female; age range from 29 to 85) with acute coronary syndrome were subjected to a blood biochemical test, including quantification of TNF-α levels and IgG and IgM to Candida albicans was determined. Results: Fungi of the genus Candida were identified in 31.9% (15 out of 47) of atherosclerotic plaques. Particularly, Candida krusii and Candida grabrata were identified in overwhelming majority, although solitary colonies of Candida tropicalis and a single colony of Candida albicans were also detected. 80 (100%) patients were negative for IgM, but 30 (37.5%) were positive for IgG to Candida albicans. TNF-α was detected in a smaller quantity of IgG-negative patients (36.7%) relative to patients of IgG-positive group (70%), however its levels were considerably above in the first group (511.73±195.80 pg/ml) than in the second one (326.68±259.91 pg/ml, P < 0.05). Differences in the levels of ASAT and ALAT in patients positive to Candida albicans and negative for TNF-α were significantly higher than in the rest of patients. Conclusion: It is conceivable that fungi of the genus Candida are capable of inducing an inflammation of the vascular wall that in turn can lead to the development of atherosclerosis. PMID:25232398

  4. Candida albicans binds to saliva proteins selectively adsorbed to silicone.

    PubMed

    Holmes, Ann R; van der Wielen, Pauline; Cannon, Richard D; Ruske, Dean; Dawes, Patrick

    2006-10-01

    Explanted voice prostheses obtained from 5 patients at the time of prosthesis replacement were consistently colonized by yeast, in particular Candida albicans. A simple, reproducible, in vitro model of C. albicans adherence to saliva-coated voice prosthesis silicone was developed. Whole saliva promoted adherence of C. albicans to silicone in a dose-dependent manner. Saliva rinses from voice prosthesis patients also promoted binding of C. albicans to silicone in vitro (mean adherence 14.9% +/- 2.8% of input C. albicans cells). This was significantly higher than C. albicans adherence to silicone in the absence of saliva (P < .001) or adherence promoted by saliva rinses from healthy volunteers (P < .005). Polyacrylamide gel electrophoresis analysis and a blot overlay adherence assay revealed that certain salivary proteins were selectively adsorbed to silicone and that C. albicans yeast cells adhered specifically to the adsorbed salivary proteins. PMID:16997116

  5. Application of CHROMagar Candida for rapid screening of clinical specimens for Candida albicans, Candida tropicalis, Candida krusei, and Candida (Torulopsis) glabrata.

    PubMed Central

    Pfaller, M A; Houston, A; Coffmann, S

    1996-01-01

    CHROMagar Candida is a new differential culture medium that allows selective isolation of yeasts and simultaneously identifies colonies of Candida albicans, C. tropicalis, and C. krusei. We evaluated the use of this medium with 316 yeast isolates including 247 isolated directly on CHROMagar from clinical material. Over 95% of stock and clinical isolates of C. albicans, C. tropicalis, and C. krusei were correctly identified on the basis of colony morphology and pigmentation on CHROMagar. Additionally, CHROMagar also allowed the identification of C. (Torulopsis) glabrata at a similar level of accuracy. The overall agreement between two observers in reading the CHROMagar plates was 95%. Growth of Candida sp. isolates on CHROMagar had no adverse effect on antifungal MICs or Vitek identification results. In parallel, cultures of 548 stool and rectal swab specimens set up on CHROMagar and Sabouraud glucose agar (SGA) were positive in 234 instances. CHROMagar was positive and SGA was negative for 11 specimens, and CHROMagar was negative and SGA was positive for 18 specimens. A single yeast species was isolated on both media from 162 specimens, and in 146 (90%) of these specimens the same species was detected on both CHROMagar and SGA. A total of 43 of the 234 positive cultures contained mixtures of yeast species. Twenty (47%) of these mixed cultures were detected only on CHROMagar. CHROMagar is extremely useful in making a rapid presumptive identification of common yeast species. This capability plus the ability to detect mixed cultures of Candida spp. promises to improve and streamline the work flow in the mycology and clinical microbiology laboratory. PMID:8748273

  6. Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.

    PubMed

    Ginsburg, I; Koren, E; Feuerstein, O; Zogakis, I P; Shalish, M; Gorelik, S

    2015-10-01

    The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity. PMID:26223507

  7. High-frequency switching in Candida albicans.

    PubMed Central

    Soll, D R

    1992-01-01

    Most strains of Candida albicans are capable of switching frequently and reversibly between a number of phenotypes distinguishable by colony morphology. A number of different switching systems have been defined according to the limited set of phenotypes in each switching repertoire, and each strain appears to possess a single system. Switching can affect many aspects of cellular physiology and morphology and appears to be a second level of phenotypic variability superimposed upon the bud-hypha transition. The most dramatic switching system so far identified is the "white-opaque transition." This system dramatizes the extraordinary effects switching can have on the budding cell phenotype, including the synthesis of opaque-specific antigens, the expression of white-specific and opaque-specific genes, and the genesis of unique cell wall structures. Switching has been demonstrated to occur at sites of infection and between episodes of recurrent vaginitis, and it may function to generate variability in commensal and infecting populations for adaptive reasons. Although the molecular mechanisms involved in the switch event are not understood, recent approaches to its elucidation are discussed and an epigenetic mechanism is proposed. Images PMID:1576587

  8. Synthetic arylquinuclidine derivatives exhibit antifungal activity against Candida albicans, Candida tropicalis and Candida parapsilopsis

    PubMed Central

    2011-01-01

    Background Sterol biosynthesis is an essential pathway for fungal survival, and is the biochemical target of many antifungal agents. The antifungal drugs most widely used to treated fungal infections are compounds that inhibit cytochrome P450-dependent C14α-demethylase (CYP51), but other enzymes of this pathway, such as squalene synthase (SQS) which catalyses the first committed step in sterol biosynthesis, could be viable targets. The aim of this study was to evaluate the antifungal activity of SQS inhibitors on Candida albicans, Candida tropicalis and Candida parapsilopsis strains. Methods Ten arylquinuclidines that act as SQS inhibitors were tested as antiproliferative agents against three ATCC strains and 54 clinical isolates of Candida albicans, Candida tropicalis and Candida parapsilopsis. Also, the morphological alterations induced in the yeasts by the experimental compounds were evaluated by fluorescence and transmission electron microscopy. Results The most potent arylquinuclidine derivative (3-[1'-{4'-(benzyloxy)-phenyl}]-quinuclidine-2-ene) (WSP1267) had a MIC50 of 2 μg/ml for all species tested and MIC90 varying from 4 μg/ml to 8 μg/ml. Ultrathin sections of C. albicans treated with 1 μg/ml of WSP1267 showed several ultrastructural alterations, including (a) loss of cell wall integrity, (b) detachment of the plasma membrane from the fungal cell wall, (c) accumulation of small vesicles in the periplasmic region, (d) presence of large electron-dense vacuoles and (e) significantly increased cell size and cell wall thickness. In addition, fluorescence microscopy of cells labelled with Nile Red showed an accumulation of lipid droplets in the cytoplasm of treated yeasts. Nuclear staining with DAPI revealed the appearance of uncommon yeast buds without a nucleus or with two nuclei. Conclusion Taken together, our data demonstrate that arylquinuclidine derivatives could be useful as lead compounds for the rational synthesis of new antifungal drugs. PMID

  9. Yeasts isolated from Algerian infants's feces revealed a burden of Candida albicans species, non-albicans Candida species and Saccharomyces cerevisiae.

    PubMed

    Seddik, Hamza Ait; Ceugniez, Alexandre; Bendali, Farida; Cudennec, Benoit; Drider, Djamel

    2016-01-01

    This study aimed at showing the yeast diversity in feces of Algerian infants, aged between 1 and 24 months, hospitalized at Bejaia hospital (northeast side of the country). Thus, 20 colonies with yeast characteristics were isolated and identified using biochemical (ID32C Api system) and molecular (sequencing of ITS1-5.8S-ITS2 region) methods. Almost all colonies isolated (19 strains) were identified as Candida spp., with predominance of Candida albicans species, and one strain was identified as Saccharomyces cerevisiae. Screening of strains with inhibitory activities unveiled the potential of Candida parapsilosis P48L1 and Candida albicans P51L1 to inhibit the growth of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Further studies performed with these two Candida strains revealed their susceptibility to clinically used antifungal compounds and were then characterized for their cytotoxicity and hemolytic properties. On the other hand, Saccharomyces cerevisiae P9L1 isolated as well in this study was shown to be devoid of antagonism but resulted safe and overall usable as probiotic. PMID:26404657

  10. Selected mechanisms of molecular resistance of Candida albicans to azole drugs.

    PubMed

    Gołąbek, Karolina; Strzelczyk, Joanna Katarzyna; Owczarek, Aleksander; Cuber, Piotr; Ślemp-Migiel, Anna; Wiczkowski, Andrzej

    2015-01-01

    A phenomenon of increasing resistance of Candida spp. to azoles has been observed for several years now. One of the mechanisms of lack of sensitivity to azoles is associated with CDR1, CDR2, MRD1 genes (their products are active transport pumps conditioning drug efflux from pathogen's cell), and ERG11 gene (encoding lanosterol 14α-demethylase). Test material was 120 strains of Candida albicans (60 resistant and 60 susceptible to azole drugs) obtained from clinical samples. The first stage of experiment assessed the expression of CDR1, CDR2, MDR1 and ERG11 genes by Q-PCR. The impact of ERG11 gene's mutations on the expression of this gene was analysed. The final stage of the experiment assessed the level of genome methylation of Candida albicans strains. An increase in the expression of CDR2, MDR1 and ERG11 was observed in azole-resistant strains of Candida albicans in comparison to strains sensitive to this class of drugs. Furthermore, 19 changes in the sequence of ERG11 were detected in tested strains. Four of the discovered mutations: T495A, A530C, G622A and A945C led to the following amino acid substitutions: D116E, K128T, V159I and E266D, respectively. It has also been found that statistically five mutations: T462C, G1309A, C216T, C1257T and A945C affected the expression of ERG11. The applied method of assessing the level of methylation of Candida albicans genome did not confirm its role in the development of resistance to azoles. The results indicate however, that resistance of Candida albicans strains to azole drugs is multifactorial. PMID:25901298

  11. Candida albicans Airway Colonization Facilitates Subsequent Acinetobacter baumannii Pneumonia in a Rat Model.

    PubMed

    Tan, Xiaojiang; Chen, Ruilan; Zhu, Song; Wang, Huijun; Yan, Dongxing; Zhang, Xiangdong; Farmakiotis, Dimitrios; Mylonakis, Eleftherios

    2016-06-01

    The objective of the study was to determine the effects of Candida albicans respiratory tract colonization on Acinetobacter baumannii pneumonia in a rat model. Rats were colonized with C. albicans by instillation of 3 × 10(6) CFU into their airways, while sterile saline was instilled in the control group. The colonized rats were further divided into two groups: treated with amphotericin B or not. The rats were subsequently infected with A. baumannii (10(8) CFU by tracheobronchial instillation). A. baumannii lung CFU counts, cytokine lung levels, and rates of A. baumannii pneumonia were compared between groups. In vitro expression of A. baumannii virulence genes was measured by reverse transcription (RT)-PCR after 24-hour incubation with C. albicans or with Mueller-Hinton (MH) broth alone. Rats with Candida colonization developed A. baumannii pneumonia more frequently and had higher A. baumannii CFU burdens and heavier lungs than controls. After A. baumannii infection, lung interleukin 17 (IL-17) concentrations were lower and gamma interferon (IFN-γ) concentrations were higher in Candida-colonized rats than in controls. Candida-colonized rats treated with amphotericin B had a decreased rate of A. baumannii pneumonia and lower IFN-γ levels but higher IL-17 levels than untreated rats. Expression of basC, barB, bauA, ptk, plc2, and pld2 was induced while expression of ompA and abaI was suppressed in A. baumannii cultured in the presence of C. albicans C. albicans colonization facilitated the development of A. baumannii pneumonia in a rat model. Among Candida-colonized rats, antifungal treatment lowered the incidence of A. baumannii pneumonia. These findings could be due to modification of the host immune response and/or expression of A. baumannii virulence genes by Candida spp. PMID:27001817

  12. The influence of photodynamic therapy parameters on the inactivation of Candida spp: in vitro and in vivo studies

    NASA Astrophysics Data System (ADS)

    Alves, F.; Mima, E. G.; Dovigo, L. N.; Bagnato, V. S.; Jorge, J. H.; de Souza Costa, C. A.; Pavarina, A. C.

    2014-04-01

    The influence of parameters of photodynamic therapy (PDT), such as pre-irradiation time (PIT), on the inactivation of Candida spp. was assessed in vitro and in vivo. Suspensions of Candida albicans, Candida tropicalis, Candida krusei and Candida glabrata were treated with Photogem®, incubated for 5, 10 or 15 min and illuminated with a blue LED light. Colonies were cultivated and log values of CFU ml-1 were analyzed by ANOVA and Kruskall-Wallis test. For in vivo evaluation, immunosuppressed mice were inoculated with C. albicans. PDT was performed on the dorsum of the tongue by topical administration of Photogem® and illumination after 5, 10 or 15 min. C. albicans was recovered from the tongue and the number of CFU ml-1 was analyzed by ANOVA and Tukey test. Animals were killed and the tongues were surgically removed for histological analysis. Susceptibility of Candida spp. suspensions to PDT was in decreasing order: C. albicans = C. tropicalis < C. krusei < C. glabrata. No significant difference was observed among the different PIT (p > 0.05), both in vivo and in vitro. A significant reduction (p < 0.05) of log(CFU ml-1) of C. albicans from tongues of mice was observed with no adverse effects in the tissue. PDT was effective to inactivate in vitroCandida spp. and for reduction of C. albicans in vivo, independently of the PIT used.

  13. Candida species and C. albicans biotypes in women attending clinics in genitourinary medicine.

    PubMed

    Odds, F C; Webster, C E; Fisk, P G; Riley, V C; Mayuranathan, P; Simmons, P D

    1989-05-01

    Yeasts were isolated from two or more anatomical sites in 198 women attending genitourinary clinics on at least two occasions. The yeast biotypes isolated concurrently from the vagina and urethra were the same in 138 (99%) of 140 instances, and 94% of 124 concurrent genital and anal isolates were of matching types, whereas only 75% of concurrent genital and oral isolates were of the same type. Mixtures of Candida spp. or C. albicans biotypes were encountered only five times among 545 yeast-positive samples. In instances where Candida spp. were isolated at successive times from the same site in a patient, the same yeast type was encountered on 97 (87%) of 112 occasions when the interval between samples was less than 15 weeks, and on 19 (66%) of 29 occasions when the interval was 15 weeks or more. These data indicate a tendency to carriage of phenotypically consistent types of Candida among most women attending genitourinary clinics. PMID:2657069

  14. Candida albicans, the opportunist. A cellular and molecular perspective.

    PubMed

    Dupont, P F

    1995-02-01

    Candida albicans causes the majority of opportunistic fungal infections. The yeast's commensualistic relationship with humans enables it, when environmental conditions are favorable, to multiply and replace much of the normal flora. Virulence factors of C. albicans, enabling the organism to adhere to and penetrate host tissues, involve specific molecular interactions between the cells of the fungus and the host. Localized disease, such as oral candidiasis, onychomycosis, and vaginitis, results. These infections are usually limited to surfaces of the host, and can be quickly and successfully controlled by the use of one of the available antifungal agents. Candida albicans infections typically become systemic and life threatening when the host is immunocompromised. Depending on the immune defect in the host, one of the spectrum of Candida diseases can develop. If successful treatment of these patients is to be achieved, modulation of the immune deficit, as well as the use of an appropriate antifungal drug, must become a routine part of therapeutic interventions. PMID:7877106

  15. Innate immune cell response upon Candida albicans infection.

    PubMed

    Qin, Yulin; Zhang, Lulu; Xu, Zheng; Zhang, Jinyu; Jiang, Yuan-Ying; Cao, Yongbing; Yan, Tianhua

    2016-07-01

    Candida albicans is a polymorphic fungus which is the predominant cause of superficial and deep tissue fungal infections. This microorganism has developed efficient strategies to invade the host and evade host defense systems. However, the host immune system will be prepared for defense against the microbe by recognition of receptors, activation of signal transduction pathways and cooperation of immune cells. As a consequence, C. albicans could either be eliminated by immune cells rapidly or disseminate hematogenously, leading to life-threatening systemic infections. The interplay between Candida albicans and the host is complex, requiring recognition of the invaded pathogens, activation of intricate pathways and collaboration of various immune cells. In this review, we will focus on the effects of innate immunity that emphasize the first line protection of host defense against invaded C. albicans including the basis of receptor-mediated recognition and the mechanisms of cell-mediated immunity. PMID:27078171

  16. Vulvovaginal Candida albicans infections: pathogenesis, immunity and vaccine prospects.

    PubMed

    Cassone, A

    2015-05-01

    Although a number of fungal species belonging to the genus Candida can cause acute vulvovaginal infection (VVC), Candida albicans is by far the most prevalent etiological agent, particularly for the most severe chronic condition known as recurrent vulvovaginal candidiasis (RVVC). This review focuses on recent advances in pathogenic mechanisms and host immune responses to C. albicans and on the utilisation of this information in the development of a vaccine to prevent and/or treat vaginal candidiasis. Currently, two vaccines with main or sole RVVC as clinical indication have completed a phase 1 clinical trial, and one of them has entered a phase 2 trial. PMID:25052208

  17. Determination of MICs of aminocandin for Candida spp. and filamentous fungi.

    PubMed

    Isham, N; Ghannoum, M A

    2006-12-01

    Candida and Aspergillus spp., as well as other filamentous molds, have increasingly been reported as the causes of severe invasive fungal infections. We evaluated the new echinocandin aminocandin (AMN) for its antifungal activities against a range of fungal pathogens by determination of the MICs for the organisms. The MICs of the comparator drugs amphotericin B, caspofungin, micafungin, and voriconazole were also determined. The MICs of AMN for 25 strains each of non-Candida albicans Candida spp. (including Candida parapsilosis, Candida krusei, Candida guilliermondii, and Candida tropicalis), Aspergillus fumigatus, Scedosporium spp., Fusarium spp., and zygomycetes (including Absidia, Mucor, and Rhizopus spp.) were determined by using the Clinical and Laboratory Standards Institute M27-A2 and M38-A methodologies for yeasts and filamentous molds, respectively. The MIC ranges of AMN for all yeasts were similar (0.03 to 4.0 microg/ml), while the MIC ranges of AMN for filamentous fungi were species specific. AMN demonstrated potent antifungal activity against A. fumigatus, limited activity against Scedosporium spp., and no activity against zygomycetes or Fusarium spp. Our data showed that AMN demonstrated potent antifungal activities against all of the yeasts and Aspergillus isolates tested, suggesting that AMN could be an important addition to our arsenal of antifungals for the treatment of invasive fungal disease. PMID:17021057

  18. Analysis of Candida albicans adhesion to salivary mucin.

    PubMed Central

    Hoffman, M P; Haidaris, C G

    1993-01-01

    Clearance of Candida albicans from the oral cavity is thought to be mediated via specific receptor-ligand interactions between salivary constituents and the fungus. Since surfaces in the oral cavity are normally coated with a saliva-derived pellicle, specific interactions between salivary constituents and C. albicans may also contribute to adhesion of C. albicans to the oral mucosa and dental prostheses. Therefore, the purpose of this study was to identify salivary constituents to which C. albicans is capable of binding. A solid-phase overlay assay was used in which electrophoretically separated rat and human salivary constituents bound to membrane filters were incubated with radiolabelled C. albicans cells. C. albicans adhered to a single salivary component from each host. Correlation of cell-binding activity with specific monoclonal antibody (MAb)-binding activity indicated that the constituent bound by C. albicans in human saliva was low-molecular-weight mucin (MG2) and that in rat saliva was rat submandibular gland (RSMG) mucin. Further studies showed an identical cell hybridization signal and MAb colocalization by using RSMG ductal saliva and an aqueous RSMG extract in the solid-phase overlay assay. Analysis of cell binding to the aqueous extract of RSMG fractionated by anion-exchange chromatography demonstrated that C. albicans binding was restricted to an acidic subfraction of the RSMG extract, which also bound the RSMG mucin-specific MAb. The Candida-binding fraction contained predominantly RSMG mucin glycoprotein and also a noncovalently associated, chloroform-extractable material. Furthermore, we identified two strains of C. albicans which differed severalfold in the ability to bind RSMG mucin in the overlay assay. These results suggest that C. albicans binds to only a specific subfraction of RSMG mucin and that the two C. albicans strains tested differ in the ability to bind RSMG mucin subfractions. Images PMID:8478083

  19. Recurrent Candida albicans Ventriculitis Treated with Intraventricular Liposomal Amphotericin B

    PubMed Central

    Toprak, Demet; Öcal Demir, Sevliya; Kadayifci, Eda Kepenekli; Türel, Özden; Soysal, Ahmet; Bakir, Mustafa

    2015-01-01

    Central nervous system (CNS) infection with Candida is rare but significant because of its high morbidity and mortality. When present, it is commonly seen among immunocompromised and hospitalized patients. Herein, we describe a case of a four-year-old boy with acute lymphoblastic leukemia (ALL) who experienced recurrent Candida albicans meningitis. The patient was treated successfully with intravenous liposomal amphotericin B at first attack, but 25 days after discharge he was readmitted to hospital with symptoms of meningitis. Candida albicans was grown in CFS culture again and cranial magnetic resonance imaging (MRI) showed ventriculitis. We administered liposomal amphotericin B both intravenously and intraventricularly and favorable result was achieved without any adverse effects. Intraventricular amphotericin B may be considered for the treatment of recurrent CNS Candida infections in addition to intravenous administration. PMID:26558119

  20. Evaluation of Bichro-Dubli Fumouze to distinguish Candida dubliniensis from Candida albicans.

    PubMed

    Sahand, Ismail H; Moragues, María D; Robert, Raymond; Quindós, Guillermo; Pontón, José

    2006-06-01

    We have evaluated the ability of the Bichro-Dubli Fumouze (Fumouze Diagnostics, Levallois-Perret, France) latex agglutination test to identify colonies of Candida dubliniensis grown on different media. The test was positive for 103 of 106 isolates of C. dubliniensis and negative for Candida albicans and other Candida species studied. The sensitivity and specificity of the test were 97.1% and 100%, respectively. The test is very rapid, simple, and reliable giving the same results independently of whether the colonies are grown previously on Sabouraud dextrose agar, CHROMagar Candida medium, Candida ID2 medium, or CHROMagar-Pal's medium. PMID:16529902

  1. Casein Agar: a Useful Medium for Differentiating Candida dubliniensis from Candida albicans

    PubMed Central

    Mosca, Christian O.; Moragues, María D.; Llovo, José; Al Mosaid, Asmaa; Coleman, David C.; Pontón, José

    2003-01-01

    Production of chlamydospores on casein agar at 24°C for 48 h provides a simple means for differentiating Candida dubliniensis from Candida albicans based on chlamydospore production. Of 109 C. dubliniensis isolates tested on this medium, 106 (97.2%) produced abundant chlamydospores and three produced few chlamydospores. In contrast, of the 120 C. albicans isolates tested, 111 (92.5%) failed to produce any chlamydospores, whereas the remaining nine isolates produced few chlamydospores. These findings indicate that abundant chlamydospore production on casein agar is a useful test for discriminating between C. dubliniensis and C. albicans. PMID:12624062

  2. Sensitization of Candida albicans to terbinafine by berberine and berberrubine

    PubMed Central

    LAM, PIKLING; KOK, STANTON HON LUNG; LEE, KENNETH KA HO; LAM, KIM HUNG; HAU, DESMOND KWOK PO; WONG, WAI YEUNG; BIAN, ZHAOXIANG; GAMBARI, ROBERTO; CHUI, CHUNG HIN

    2016-01-01

    Candida albicans (C. albicans) is an opportunistic fungal pathogen, particularly observed in immunocompromised patients. C. albicans accounts for 50–70% of cases of invasive candidiasis in the majority of clinical settings. Terbinafine, an allylamine antifungal drug, has been used to treat fungal infections previously. It has fungistatic activity against C. albicans. Traditional Chinese medicines can be used as complementary medicines to conventional drugs to treat a variety of ailments and diseases. Berberine is a quaternary alkaloid isolated from the traditional Chinese herb, Coptidis Rhizoma, while berberrubine is isolated from the medicinal plant Berberis vulgaris, but is also readily derived from berberine by pyrolysis. The present study demonstrates the possible complementary use of berberine and berberrubine with terbinafine against C. albicans. The experimental findings assume that the potential application of these alkaloids together with reduced dosage of the standard drug would enhance the resulting antifungal potency. PMID:27073630

  3. 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

  4. 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. PMID:27261732

  5. Candida arthritis: cellular immune responses of synovial fluid and peripheral blood lymphocytes to Candida albicans.

    PubMed Central

    Hermann, E; Mayet, W J; Klein, O; Lohse, A W; Trautwein, C; Michiels, I; Poralla, T; Meyer zum Büschenfelde, K H

    1991-01-01

    A case of septic Candida albicans arthritis of the knee in a patient with systemic candidiasis is presented. Systemic and intra-articular cellular immune responses to C albicans and various bacterial antigens were monitored for 15 weeks. It is shown that the candida induced blastogenesis of synovial fluid lymphocytes was much more stimulated than that of peripheral blood lymphocytes, and that the proportion of activated cells expressing HLA class II antigens was markedly increased in the synovial fluid. Strong cellular immune responses to Candida albicans could still be shown many weeks after the synovial fluid aspirates had become sterile. For the first time synovial fluid derived, CD4 positive T lymphocyte clones with specificity for candida antigens were characterised and further propagated in vitro. Images PMID:1720301

  6. The antimicrobial effects of selenium nanoparticle-enriched probiotics and their fermented broth against Candida albicans

    PubMed Central

    2014-01-01

    Background Lactic acid bacteria are considered important probiotics for prevention of some infections. The aim of this work was to investigate the effect of selenium dioxide on the antifungal activity of Lactobacillus plantarum and L. johnsonii against Candida albicans. Methods Lactobacillus plantarum and L. johnsonii cells, grown in the presence and absence of selenium dioxide, and their cell-free spent culture media were tested for antifungal activity against C. albicans ATCC 14053 by a hole-plate diffusion method and a time-kill assay. Results Both L. plantarum and L. johnsonii reduced selenium dioxide to cell-associated elemental selenium nanoparticles. The cell-free spent culture media, from both Lactobacillus species that had been grown with selenium dioxide for 48 h, showed enhanced antifungal activity against C. albicans. Enhanced antifungal activity of cell biomass against C. albicans was also observed in cultures grown with selenium dioxide. Conclusions Selenium dioxide-treated Lactobacillus spp. or their cell-free spent broth inhibited the growth of C. albicans and should be investigated for possible use in anti-Candida probiotic formulations in future. PMID:24906455

  7. Two unlike cousins: Candida albicans and C. glabrata infection strategies

    PubMed Central

    Brunke, Sascha; Hube, Bernhard

    2013-01-01

    Candida albicans and C. glabrata are the two most common pathogenic yeasts of humans, yet they are phylogenetically, genetically and phenotypically very different. In this review, we compare and contrast the strategies of C. albicans and C. glabrata to attach to and invade into the host, obtain nutrients and evade the host immune response. Although their strategies share some basic concepts, they differ greatly in their outcome. While C. albicans follows an aggressive strategy to subvert the host response and to obtain nutrients for its survival, C. glabrata seems to have evolved a strategy which is based on stealth, evasion and persistence, without causing severe damage in murine models. However, both fungi are successful as commensals and as pathogens of humans. Understanding these strategies will help in finding novel ways to fight Candida, and fungal infections in general. PMID:23253282

  8. Gymnemic acids inhibit hyphal growth and virulence in Candida albicans.

    PubMed

    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

  9. Uptake and antifungal activity of oligonucleotides in Candida albicans

    PubMed Central

    Disney, Matthew D.; Haidaris, Constantine G.; Turner, Douglas H.

    2003-01-01

    Candida albicans is a significant cause of disease in immunocompromised humans. Because the number of people infected by fungal pathogens is increasing, strategies are being developed to target RNAs in fungi. This work shows that oligonucleotides can serve as therapeutics against C. albicans. In particular, oligonucleotides are taken up from cell culture medium in an energy-dependent process. After uptake, oligonucleotides, including RNA, remain mostly intact after 12 h in culture. For culture conditions designed for mammalian cells, intracellular concentrations of oligonucleotides in C. albicans exceed those in COS-7 mammalian cells, suggesting that uptake can provide selective targeting of fungi over human cells. A 19-mer 2′OMe (oligonucleotide with a 2′-O-methyl backbone) hairpin is described that inhibits growth of a C. albicans strain at pH < 4.0. This pH is easily tolerated in some parts of the body subject to C. albicans infections. In vivo dimethyl sulfate modification of ribosomal RNA and the decreased rate of protein synthesis suggest that this hairpin's activity may be due to targeting the ribosome in a way that does not depend on base pairing. Addition of anti-C. albicans oligonucleotides to COS-7 mammalian cells has no effect on cell growth. Evidently, oligonucleotides can selectively serve as therapeutics toward C. albicans and, presumably, other pathogens. Information from genome sequencing and functional genomics studies on C. albicans and other pathogens should allow rapid design and testing of other approaches for oligonucleotide therapies. PMID:12552085

  10. IL-17 Signaling in Host Defense Against Candida albicans

    PubMed Central

    Gaffen, Sarah L.; Hernandez-Santos, Nydiaris; Peterson, Alanna C.

    2012-01-01

    The discovery of the Th17 lineage in 2005 triggered a major change in how immunity to infectious diseases is viewed. Fungal infections, in particular, have long been a relatively understudied area of investigation in terms of the host immune response. Candida albicans is a commensal yeast that colonizes mucosal sites and skin. In healthy individuals it is non-pathogenic, but in conditions of immune deficiency, this organism can cause a variety of infections associated with considerable morbidity. Candida can also cause disseminated infections that have a high mortality rate and are a major clinical problem in hospital settings. Although immunity to Candida albicans was long considered to be mediated by Th1 cells, new data in both rodent models and in humans have revealed an essential role for the Th17 lineage, and in particular its signature cytokine IL-17. PMID:21717069

  11. Baicalin prevents Candida albicans infections via increasing its apoptosis rate

    SciTech Connect

    Yang, Shulong; Fu, Yingyuan Wu, Xiuzhen; Zhou, Zhixing; Xu, Jing; Zeng, Xiaoping; Kuang, Nanzhen; Zeng, Yurong

    2014-08-15

    Highlights: • Baicalin increases the ratio of the G0/G1 stages and C. albicans apoptosis. • Baicalin decreases the proliferation index of C. albicans. • Baicalin inhibits the biosynthesis of DNA, RNA and protein in C. albicans. • Baicalin depresses Succinate Dehydrogenase and Ca{sup 2+}–Mg{sup 2+} ATPase in C. albicans. • Baicalin increases the endocytic free Ca{sup 2+} concentration in C. albicans. - Abstract: Background: These experiments were employed to explore the mechanisms underlying baicalin action on Candida albicans. Methodology and principal findings: We detected the baicalin inhibition effects on three isotope-labeled precursors of {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C. albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca{sup 2+}–Mg{sup 2+} ATPase, cytosolic Ca{sup 2+} concentration, the cell cycle and apoptosis, as well as the ultrastructure of C.albicans were also tested. We found that baicalin inhibited {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C.albicans (P < 0.005). The activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase of C.albicans in baicalin groups were lower than those in control group (P < 0.05). Ca{sup 2+} concentrations of C. albicans in baicalin groups were much higher than those in control group (P < 0.05). The ratio of C.albicans at the G0/G1 stage increased in baicalin groups in dose dependent manner (P < 0.01). There were a significant differences in the apoptosis rate of C.albicans between baicalin and control groups (P < 0.01). After 12–48 h incubation with baicalin (1 mg/ml), C. albicans shown to be markedly damaged under transmission electron micrographs. Innovation and significance: Baicalin can increase the apoptosis rate of C. albicans. These effects of Baicalin may involved in its inhibiting the activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase, increasing

  12. Postantifungal Effect of Micafungin against the Species Complexes of Candida albicans and Candida parapsilosis

    PubMed Central

    Gil-Alonso, Sandra; Jauregizar, Nerea; Eraso, Elena; Quindós, Guillermo

    2015-01-01

    Micafungin is an effective antifungal agent useful for the therapy of invasive candidiasis. Candida albicans is the most common cause of invasive candidiasis; however, infections due to non-C. albicans species, such as Candida parapsilosis, are rising. Killing and postantifungal effects (PAFE) are important factors in both dose interval choice and infection outcome. The aim of this study was to determinate the micafungin PAFE against 7 C. albicans strains, 5 Candida dubliniensis, 2 Candida Africana, 3 C. parapsilosis, 2 Candida metapsilosis and 2 Candida orthopsilosis. For PAFE studies, cells were exposed to micafungin for 1 h at concentrations ranging from 0.12 to 8 μg/ml. Time-kill experiments (TK) were conducted at the same concentrations. Samples were removed at each time point (0-48 h) and viable counts determined. Micafungin (2 μg/ml) was fungicidal (≥ 3 log10 reduction) in TK against 5 out of 14 (36%) strains of C. albicans complex. In PAFE experiments, fungicidal endpoint was achieved against 2 out of 14 strains (14%). In TK against C. parapsilosis, 8 μg/ml of micafungin turned out to be fungicidal against 4 out 7 (57%) strains. Conversely, fungicidal endpoint was not achieved in PAFE studies. PAFE results for C. albicans complex (41.83 ± 2.18 h) differed from C. parapsilosis complex (8.07 ± 4.2 h) at the highest tested concentration of micafungin. In conclusion, micafungin showed significant differences in PAFE against C. albicans and C. parapsilosis complexes, being PAFE for the C. albicans complex longer than for the C. parapsilosis complex. PMID:26168269

  13. VINEGAR AS AN ANTIMICROBIAL AGENT FOR CONTROL OF Candida spp. IN COMPLETE DENTURE WEARERS

    PubMed Central

    Pinto, Telma Maria Silva; Neves, Ana Christina Claro; Leão, Mariella Vieira Pereira; Jorge, Antonio Olavo Cardoso

    2008-01-01

    The use of denture is known to increase the carriage of Candida in healthy patients, and the proliferation of Candida albicans strains can be associated with denture-induced stomatitis. The aim of this study was to evaluate the use of vinegar as an antimicrobial agent for control of Candida spp. in complete upper denture wearers. Fifty-five patients were submitted to a detailed clinical interview and oral clinical examination, and were instructed to keep their dentures immersed in a 10% vinegar solution (pH less than 3) overnight for 45 days. Before and after the experimental period, saliva samples were collected for detection of Candida, counting of cfu/mL and identification of species by phenotypical tests (germ tube formation, chlamidoconidia production, and carbohydrate fermentation and assimilation). The results were analyzed using Spearman's correlation and Student's t-test (p≤0.05). Candida yeasts were present in 87.3% of saliva samples before the treatment. A significant reduction was verified in CFU/mL counts of Candida after treatment. A positive correlation between Candida and denture stomatitis was verified, since the decrease of cfu/mL counts was correlated with a reduction in cases of denture stomatitis. Although it was not able to eliminate C. albicans, the immersion of the complete denture in 10% vinegar solution, during the night, reduced the amounts (cfu/mL) of Candida spp. in the saliva and the presence of denture stomatitis in the studied patients. PMID:19082396

  14. Molecular genetic techniques for gene manipulation in Candida albicans

    PubMed Central

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

    2014-01-01

    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. PMID:24759671

  15. Cloning, purification, and properties of Candida albicans thymidylate synthase.

    PubMed Central

    Singer, S C; Richards, C A; Ferone, R; Benedict, D; Ray, P

    1989-01-01

    The thymidylate synthase (TS) gene was isolated from a genomic Candida albicans library by functional complementation of a Saccharomyces cerevisiae strain deficient in TS. The gene was localized on a 4-kilobase HindIII DNA fragment and was shown to be expressed in a Thy- strain of Escherichia coli. The nucleotide sequence of the TS gene predicted a protein of 315 amino acids with a molecular weight of 36,027. The gene was cloned into a T7 expression vector in E. coli, allowing purification of large amounts of C. albicans TS. It was also purified from a wild-type C. albicans strain. Comparison of several enzyme properties including analysis of amino-terminal amino acid sequences showed the native and cloned C. albicans TS to be the same. PMID:2646281

  16. In vitro activity of eugenol against Candida albicans biofilms.

    PubMed

    He, Miao; Du, Minquan; Fan, Mingwen; Bian, Zhuan

    2007-03-01

    Most manifestations of candidiasis are associated with biofilm formation occurring on the surfaces of host tissues and medical devices. Candida albicans is the most frequently isolated causative pathogen of candidiasis, and the biofilms display significantly increased levels of resistance to the conventional antifungal agents. Eugenol, the major phenolic component of clove essential oil, possesses potent antifungal activity. The aim of this study was to investigate the effects of eugenol on preformed biofilms, adherent cells, subsequent biofilm formation and cell morphogenesis of C. albicans. Eugenol displayed in vitro activity against C. albicans cells within biofilms, when MIC(50) for sessile cells was 500 mg/L. C. albicans adherent cell populations (after 0, 1, 2 and 4 h of adherence) were treated with various concentrations of eugenol (0, 20, 200 and 2,000 mg/L). The extent of subsequent biofilm formation were then assessed with the tetrazolium salt reduction assay. Effect of eugenol on morphogenesis of C. albicans cells was observed by scanning electron microscopy (SEM). The results indicated that the effect of eugenol on adherent cells and subsequent biofilm formation was dependent on the initial adherence time and the concentration of this compound, and that eugenol can inhibit filamentous growth of C. albicans cells. In addition, using human erythrocytes, eugenol showed low hemolytic activity. These results indicated that eugenol displayed potent activity against C. albicans biofilms in vitro with low cytotoxicity and therefore has potential therapeutic implication for biofilm-associated candidal infections. PMID:17356790

  17. Effect of Marine Polyunsaturated Fatty Acids on Biofilm Formation of Candida albicans and Candida dubliniensis

    PubMed Central

    Thibane, Vuyisile S.; Kock, Johan L. F.; Ells, Ruan; van Wyk, Pieter W. J.; Pohl, Carolina H.

    2010-01-01

    The effect of marine polyunsaturated fatty acids on biofilm formation by the human pathogens Candida albicans and Candida dubliniensis was investigated. It was found that stearidonic acid (18:4 n-3), eicosapentaenoic acid (20:5 n-3), docosapentaenoic acid (22:5 n-3) and docosahexaenoic acid (22:6 n-3) have an inhibitory effect on mitochondrial metabolism of both C. albicans and C. dubliniensis and that the production of biofilm biomass by C. dubliniensis was more susceptible to these fatty acids than C. albicans. Ultrastructural differences, which may be due to increased oxidative stress, were observed between treated and untreated cells of C. albicans and C. dubliniensis with formation of rough cell walls by both species and fibrillar structures in C. dubliniensis. These results indicate that marine polyunsaturated fatty acids may be useful in the treatment and/or prevention of biofilms formed by these pathogenic yeasts. PMID:21116408

  18. Doxorubicin induces drug efflux pumps in Candida albicans.

    PubMed

    Kofla, Grzegorz; Turner, Vincent; Schulz, Bettina; Storch, Ulrike; Froelich, Daniela; Rognon, Bénédicte; Coste, Alix T; Sanglard, Dominique; Ruhnke, Markus

    2011-02-01

    Candida albicans is one of the most important opportunistic fungal pathogens. It can cause serious fungal diseases in immunocompromised patients, including those with cancer. Treatment failures due to the emergence of drug-resistant C. albicans strains have become a serious clinical problem. Resistance incidents were often mediated by fungal efflux pumps which are closely related to the human ABC transporter P-glycoprotein (P-gp). P-gp is often overexpressed in cancer cells and confers resistance to many cytotoxic drugs. We examined whether cytotoxic drugs commonly used for cancer treatment (doxorubicin and cyclophosphamide) could alter the expression of genes responsible for the development of fluconazole resistance in Candida cells in the way they can influence homologous genes in cancer cell lines. ABC transporters (CDR1 and CDR2) and other resistance genes (MDR1 and ERG11) were tested by real-time PCR for their expression in C. albicans cells at the mRNA level after induction by antineoplastic drugs. The results were confirmed by a lacZ gene reporter system and verified at the protein level using GFP and immunoblotting. We showed that doxorubicin is a potent inducer of CDR1/CDR2 expression in C. albicans at both the mRNA and protein level and thus causes an increase in fluconazole MIC values. However, cyclophosphamide, which is not a substrate of human P-gp, did not induce ABC transporter expression in C. albicans. Neither doxorubicin nor cyclophosphamide could influence the expression of the other resistance genes (MDR1 and ERG11). The induction of CDR1/CDR2 by doxorubicin in C. albicans and the resulting alteration of antifungal susceptibility might be of clinical relevance for the antifungal treatment of Candida infections occurring after anticancer chemotherapy with doxorubicin. PMID:20818920

  19. The exocyst in Candida albicans polarized secretion and filamentation.

    PubMed

    Chavez-Dozal, Alba A; Bernardo, Stella M; Lee, Samuel A

    2016-05-01

    The exocyst is an octameric complex that orchestrates the docking and tethering of vesicles to the plasma membrane during exocytosis and is fundamental for key biological processes including growth and establishment of cell polarity. Although components of the exocyst are well conserved among fungi, the specific functions of each component of the exocyst complex unique to Candida albicans biology and pathogenesis are not fully understood. This commentary describes recent findings regarding the role of exocyst subunits Sec6 and Sec15 in C. albicans filamentation and virulence. PMID:26762634

  20. Induction of apoptosis in oral epithelial cells by Candida albicans.

    PubMed

    Villar, C Cunha; Chukwuedum Aniemeke, J; Zhao, X-R; Huynh-Ba, G

    2012-12-01

    During infection, interactions between Candida albicans and oral epithelial cells result in oral epithelial cell death. This is clinically manifested by the development of oral mucosal ulcerations generally associated with discomfort. In vitro studies have shown that C. albicans induces early apoptotic alterations in oral epithelial cells; however, these studies have also shown that treatment of infected cells with caspase inhibitors does not prevent their death. The reasons for these contradictory results are unknown and it is still not clear if C. albicans stimulates oral epithelial signaling pathways that promote apoptotic cell death. Activation of specific death pathways in response to microbial organisms plays an essential role in modulating the pathogenesis of a variety of infectious diseases. The aim of this study was to (i) characterize C. albicans-induced apoptotic morphological alterations in oral epithelial cells, and (ii) investigate the activation of apoptotic signaling pathways and expression of apoptotic genes during infection. Candida albicans induced early apoptotic changes in over 50% of oral epithelial cells. However, only 15% of those showed mid-late apoptotic alterations. At the molecular level, C. albicans caused a loss of the mitochondrial transmembrane potential and translocation of mitochondrial cytochrome c. Caspase-3/9 activities increased only during the first hours of infection. Moreover, poly[ADP ribose] polymerase 1 was cleaved into apoptotic and necrotic-like fragments. Finally, five anti-apoptotic genes were significantly upregulated and two pro-apoptotic genes were downregulated during infection. Altogether, these findings indicate that epithelial apoptotic pathways are activated in response to C. albicans, but fail to progress and promote apoptotic cell death. PMID:23134609

  1. Design and evaluation of peptide nucleic acid probes for specific identification of Candida albicans.

    PubMed

    Kim, Hyun-Joong; Brehm-Stecher, Byron F

    2015-02-01

    Candida albicans is an important cause of systemic fungal infections, and rapid diagnostics for identifying and differentiating C. albicans from other Candida species are critical for the timely application of appropriate antimicrobial therapy, improved patient outcomes, and pharmaceutical cost savings. In this work, two 28S rRNA-directed peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) probes, P-Ca726 (targeting a novel region of the ribosome) and P-CalB2208 (targeting a previously reported region), were evaluated. Hybridization conditions were optimized by using both fluorescence microscopy (FM) and flow cytometry (FCM), and probes were screened for specificity and discriminative ability against a panel of C. albicans and various nontarget Candida spp. The performance of these PNA probes was compared quantitatively against that of DNA probes or DNA probe/helper combinations directed against the same target regions. Ratiometric analyses of FCM results indicated that both the hybridization quality and yield of the PNA probes were higher than those of the DNA probes. In FCM-based comparisons of the PNA probes, P-Ca726 was found to be highly specific, showing 2.5- to 5.5-fold-higher discriminatory power for C. albicans than P-CalB2208. The use of formamide further improved the performance of the new probe. Our results reinforce the significant practical and diagnostic advantages of PNA probes over their DNA counterparts for FISH and indicate that P-Ca726 may be used advantageously for the rapid and specific identification of C. albicans in clinical and related applications, especially when combined with FCM. PMID:25428160

  2. Design and Evaluation of Peptide Nucleic Acid Probes for Specific Identification of Candida albicans

    PubMed Central

    Kim, Hyun-Joong

    2014-01-01

    Candida albicans is an important cause of systemic fungal infections, and rapid diagnostics for identifying and differentiating C. albicans from other Candida species are critical for the timely application of appropriate antimicrobial therapy, improved patient outcomes, and pharmaceutical cost savings. In this work, two 28S rRNA-directed peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) probes, P-Ca726 (targeting a novel region of the ribosome) and P-CalB2208 (targeting a previously reported region), were evaluated. Hybridization conditions were optimized by using both fluorescence microscopy (FM) and flow cytometry (FCM), and probes were screened for specificity and discriminative ability against a panel of C. albicans and various nontarget Candida spp. The performance of these PNA probes was compared quantitatively against that of DNA probes or DNA probe/helper combinations directed against the same target regions. Ratiometric analyses of FCM results indicated that both the hybridization quality and yield of the PNA probes were higher than those of the DNA probes. In FCM-based comparisons of the PNA probes, P-Ca726 was found to be highly specific, showing 2.5- to 5.5-fold-higher discriminatory power for C. albicans than P-CalB2208. The use of formamide further improved the performance of the new probe. Our results reinforce the significant practical and diagnostic advantages of PNA probes over their DNA counterparts for FISH and indicate that P-Ca726 may be used advantageously for the rapid and specific identification of C. albicans in clinical and related applications, especially when combined with FCM. PMID:25428160

  3. Colonization of congenitally athymic, gnotobiotic mice by Candida albicans.

    PubMed Central

    Balish, E; Balish, M J; Salkowski, C A; Lee, K W; Bartizal, K F

    1984-01-01

    Colony counts, scanning electron microscopy, and light microscopy were used to assess the capacity of Candida albicans to colonize (naturally) and infect the alimentary tract of adult and neonatal (athymic [nu/nu] or heterozygous [+/nu] littermates) germfree BALB/c mice. When exposed to yeast-phase C. albicans, the alimentary tract of adult germfree mice (nu/nu or +/nu) is quickly (within 24 to 48 h) colonized with yeast cells. Neither morbidity nor mortality was evident in any mice that were colonized with a pure culture of C. albicans for 6 months. Yeast cells of C. albicans predominated on mucosal surfaces in the oral cavities and vaginas of adult athymic and heterozygous mice. In both genotypes, C. albicans hyphae were observed in keratinized tissue on the dorsal posterior tongue surface and in the cardial-atrium section of the stomach. Conversely, neonatal athymic or heterozygous mice, born to germfree or C. albicans-colonized mothers, do not become heavily colonized or infected with C. albicans until 11 to 15 days after birth. Although yeast cells adhered to some mucosal surfaces in vivo, neither widespread mucocutaneous candidiasis, i.e., invasion of mucosal surfaces with C. albicans hyphae, nor overwhelming systemic candidiasis was evident in neonatal (nu/nu or +/nu) mice. Thus, even in the absence of functional T-cells and a viable bacterial flora, athymic and heterozygous littermate mice (adult or neonatal BALB/c) that are colonized with a pure culture of C. albicans manifest resistance to extensive mucocutaneous and systemic candidiasis. Images PMID:6372689

  4. Identification and Characterization of a Candida albicans Mating Pheromone

    PubMed Central

    Bennett, Richard J.; Uhl, M. Andrew; Miller, Mathew G.; Johnson, Alexander D.

    2003-01-01

    Candida albicans, the most prevalent fungal pathogen of humans, has recently been shown to undergo mating. Here we describe a mating pheromone produced by C. albicans α cells and show that the gene which encodes it (MFα) is required for α cells, but not a cells, to mate. We also identify the receptor for this mating pheromone as the product of the STE2 gene and show that this gene is required for the mating of a cells, but not α cells. Cells of the a mating type respond to the α mating pheromone by producing long polarized projections, similar to those observed in bona fide mating mixtures of C. albicans a and α cells. During this process, transcription of approximately 62 genes is induced. Although some of these genes correspond to those induced in Saccharomyces cerevisiae by S. cerevisiae α-factor, most are specific to the C. albicans pheromone response. The most surprising class encode cell surface and secreted proteins previously implicated in virulence of C. albicans in a mouse model of disseminated candidiasis. This observation suggests that aspects of cell-cell communication in mating may have been evolutionarily adopted for host-pathogen interactions in C. albicans. PMID:14585977

  5. Heparin-Binding Motifs and Biofilm Formation by Candida albicans

    PubMed Central

    Green, Julianne V.; Orsborn, Kris I.; Zhang, Minlu; Tan, Queenie K. G.; Greis, Kenneth D.; Porollo, Alexey; Andes, David R.; Long Lu, Jason; Hostetter, Margaret K.

    2013-01-01

    Candida albicans is a leading pathogen in infections of central venous catheters, which are frequently infused with heparin. Binding of C. albicans to medically relevant concentrations of soluble and plate-bound heparin was demonstrable by confocal microscopy and enzyme-linked immunosorbent assay (ELISA). A sequence-based search identified 34 C. albicans surface proteins containing ≥1 match to linear heparin-binding motifs. The virulence factor Int1 contained the most putative heparin-binding motifs (n = 5); peptides encompassing 2 of 5 motifs bound to heparin-Sepharose. Alanine substitution of lysine residues K805/K806 in 804QKKHQIHK811 (motif 1 of Int1) markedly attenuated biofilm formation in central venous catheters in rats, whereas alanine substitution of K1595/R1596 in 1593FKKRFFKL1600 (motif 4 of Int1) did not impair biofilm formation. Affinity-purified immunoglobulin G (IgG) recognizing motif 1 abolished biofilm formation in central venous catheters; preimmune IgG had no effect. After heparin treatment of C. albicans, soluble peptides from multiple C. albicans surface proteins were detected, such as Eno1, Pgk1, Tdh3, and Ssa1/2 but not Int1, suggesting that heparin changes candidal surface structures and may modify some antigens critical for immune recognition. These studies define a new mechanism of biofilm formation for C. albicans and a novel strategy for inhibiting catheter-associated biofilms. PMID:23904295

  6. Oxidative stress of photodynamic antimicrobial chemotherapy inhibits Candida albicans virulence

    NASA Astrophysics Data System (ADS)

    Kato, Ilka Tiemy; Prates, Renato Araujo; Tegos, George P.; Hamblin, Michael R.; Simões Ribeiro, Martha

    2011-03-01

    Photodynamic antimicrobial chemotherapy (PACT) is based on the principal that microorganisms will be inactivated using a light source combined to a photosensitizing agent in the presence of oxygen. Oxidative damage of cell components occurs by the action of reactive oxygen species leading to cell death for microbial species. It has been demonstrated that PACT is highly efficient in vitro against a wide range of pathogens, however, there is limited information for its in vivo potential. In addition, it has been demonstrated that sublethal photodynamic inactivation may alter the virulence determinants of microorganisms. In this study, we explored the effect of sublethal photodynamic inactivation to the virulence factors of Candida albicans. Methylene Blue (MB) was used as photosensitizer for sublethal photodynamic challenge on C. albicans associated with a diode laser irradiation (λ=660nm). The parameters of irradiation were selected in causing no reduction of viable cells. The potential effects of PACT on virulence determinants of C. albicans cells were investigated by analysis of germ tube formation and in vivo pathogenicity assays. Systemic infection was induced in mice by the injection of fungal suspension in the lateral caudal vein. C. albicans exposed to sublethal photodynamic inactivation formed significantly less germ tube than untreated cells. In addition, mice infected with C. albicans submitted to sublethal PACT survived for a longer period of time than mice infected with untreated cells. The oxidative damage promoted by sublethal photodynamic inactivation inhibited virulence determinants and reduced in vivo pathogenicity of C. albicans.

  7. Candida albicans and Enterococcus faecalis in the gut

    PubMed Central

    Garsin, Danielle A; Lorenz, Michael C

    2013-01-01

    The fungus Candida albicans and the gram-positive bacterium Enterococcus faecalis are both normal residents of the human gut microbiome and cause opportunistic disseminated infections in immunocompromised individuals. Using a nematode infection model, we recently showed that co-infection resulted in less pathology and less mortality than infection with either species alone and this was partly explained by an interkingdom signaling event in which a bacterial-derived product inhibits hyphal morphogenesis of C. albicans. In this addendum we discuss these findings in the contest of other described bacterial-fungal interactions and recent data suggesting a potentially synergistic relationship between these two species in the mouse gut as well. We suggest that E. faecalis and C. albicans promote a mutually beneficial association with the host, in effect choosing a commensal lifestyle over a pathogenic one. PMID:23941906

  8. Interleukin 17-Mediated Host Defense against Candida albicans

    PubMed Central

    Sparber, Florian; LeibundGut-Landmann, Salomé

    2015-01-01

    Candida albicans is part of the normal microbiota in most healthy individuals. However, it can cause opportunistic infections if host defenses are breached, with symptoms ranging from superficial lesions to severe systemic disease. The study of rare congenital defects in patients with chronic mucocutaneous candidiasis led to the identification of interleukin-17 (IL-17) as a key factor in host defense against mucosal fungal infection. Experimental infections in mice confirmed the critical role of IL-17 in mucocutaneous immunity against C. albicans. Research on mouse models has also contributed importantly to our current understanding of the regulation of IL-17 production by different cellular sources and its effector functions in distinct tissues. In this review, we highlight recent findings on IL-17-mediated immunity against C. albicans in mouse and man. PMID:26274976

  9. A morphogenetic regulatory role for ethyl alcohol in Candida albicans.

    PubMed

    Chauhan, Nitin M; Raut, Jayant S; Karuppayil, S Mohan

    2011-11-01

    Regulation of morphogenesis through the production of chemical signalling molecules such as isoamyl alcohol, 2-phenylethyl alcohol, 1-dodecanol, E-nerolidol and farnesol is reported in Candida albicans. The present study focuses on the effect of ethyl alcohol on C. albicans dimorphism and biofilm development. Ethyl alcohol inhibited germ tube formation induced by the four standard inducers in a concentration-dependent manner. The germ tube inhibitory concentration (4%) did not have any effect on the growth and viability of C. albicans cells. Ethyl alcohol also inhibited the elongation of germ tubes. Four percentage of ethyl alcohol significantly inhibited biofilm development on polystyrene and silicone surfaces. We suggest a potential morphogenetic regulatory role for ethyl alcohol, which may influence dissemination, virulence and establishment of infection. PMID:21605190

  10. Candida albicans in oral biofilms could prevent caries.

    PubMed

    Willems, Hubertine Marjoleine; Kos, Kevin; Jabra-Rizk, Mary Ann; Krom, Bastiaan P

    2016-07-01

    Streptococcus mutans is a Gram-positive bacterium involved in development to caries, the most common infectious disease of our time. Streptococcus mutans interacts with other microbes, like the fungus Candida albicans and both are commonly isolated from patients with caries. Since the role of C. albicans in caries remains unknown, our aim was to unravel this using an in vitro dual-species cariogenic oral biofilm model. Biofilms were grown for 24-72 h on glass cover slips or hydroxyapatite (HA) disks to mimic the surface of teeth. Medium pH, lactic acid production capacity and calcium release from HA disks were determined. All 24-h biofilms had external pH values below the critical pH of 5.5 where enamel dissolves. In contrast, 72-h dual-species biofilms had significantly higher pH (above the critical pH) and consequently decreased calcium release compared to single-species S. mutans biofilms. Counter intuitively, lactic acid production and growth of S. mutans were increased in 72-h dual-species biofilms. Candida albicans modulates the pH in dual-species biofilms to values above the critical pH where enamel dissolves. Our results suggest that C. albicans is not by definition a cariogenic microorganism; it could prevent caries by actively increasing pH preventing mineral loss. PMID:27129365

  11. Ocimum sanctum essential oil inhibits virulence attributes in Candida albicans.

    PubMed

    Khan, Amber; Ahmad, Aijaz; Xess, Immaculata; Khan, Luqman A; Manzoor, Nikhat

    2014-03-15

    Candida albicans is an opportunistic human fungal pathogen which causes disease mainly in immunocompromised patients. Activity of hydrolytic enzymes is essential for virulence of C. albicans and so is the capacity of these cells to undergo transition from yeast to mycelial form of growth. Ocimum sanctum is cultivated worldwide for its essential oil which exhibits medicinal properties. This work evaluates the anti-virulence activity of O. sanctum essential oil (OSEO) on 22 strains of C. albicans (including a standard strain ATCC 90028) isolated from both HIV positive and HIV negative patients. Candida isolates were exposed to sub-MICs of OSEO. In vitro secretion of proteinases and phospholipases was evaluated by plate assay containing BSA and egg yolk respectively. Morphological transition from yeast to filamentous form was monitored microscopically in LSM. For genetic analysis, respective genes associated with morphological transition (HWP1), proteinase (SAP1) and phospholipase (PLB2) were also investigated by Real Time PCR (qRT-PCR). Results were analyzed using Student's t-test. OSEO inhibits morphological transition in C. albicans and had a significant inhibitory effect on extracellular secretion of proteinases and phospholipases. Expression profile of respective selected genes associated with C. albicans virulence by qRT-PCR showed a reduced expression of HWP1, SAP1 and PLB2 genes in cells treated with sub-inhibitory concentrations of OSEO. This work suggests that OSEO inhibits morphological transition in C. albicans and decreases the secretion of hydrolytic enzymes involved in the early stage of infection as well as down regulates the associated genes. Further studies will assess the clinical application of OSEO and its constituents in the treatment of fungal infections. PMID:24252340

  12. Chlamydospore formation in Candida albicans and Candida dubliniensis--an enigmatic developmental programme.

    PubMed

    Staib, Peter; Morschhäuser, Joachim

    2007-01-01

    Chlamydospore formation has served for a long time for identification of the human fungal pathogen Candida albicans, but the biological function of these structures still remains a secret. They have been proposed to allow survival in harsh environmental conditions, but this assumption remains to be proven. Chlamydospores are produced only by the two closely related species C. albicans and Candida dubliniensis, whose natural habitats are humans and warm-blooded animals, but not by other Candida species that are also found outside animal hosts. However, no role in the pathogenesis of Candida infections has been assigned to these unusual cells and only a limited number of studies have been conducted in the past to unravel their function. The development of new molecular tools and the recent discovery of mating in C. albicans have also restimulated investigations to understand the morphogenesis and function of chlamydospores. The finding that chlamydospore formation is differentially controlled by certain environmental signals in C. albicans and C. dubliniensis has opened new approaches to study the regulation of this morphogenetic programme. These studies have already identified genes and signalling pathways that are required for chlamydospore production and should lead to a detailed understanding of this fascinating developmental process. PMID:17302741

  13. Baicalein induces programmed cell death in Candida albicans.

    PubMed

    Dai, Bao-Di; Cao, Ying-Ying; Huang, Shan; Xu, Yong-Gang; Gao, Ping-Hui; Wang, Yan; Jiang, Yuan-Ying

    2009-08-01

    Recent evidence has revealed the occurrence of an apoptotic phenotype in Candida albicans that is inducible with environmental stresses such as acetic acid, hydrogen peroxide, and amphotericin B. In the present study, we found that the Chinese herbal medicine Baicalein (BE), which was one of the skullcapflavones, can induce apoptosis in C. albicans. The apoptotic effects of BE were detected by flow cytometry using Annexin V-FITC and DAPI, and it was confirmed by transmission electron microscopy analysis. After exposure to 4 microg/ml BE for 12 h, about 10% of C. albicans cells were apoptotic. Both the increasing intracellular levels of reactive oxygen species (ROS) and upregulation of some redox-related genes (CAP1, SOD2, TRR1) were observed. Furthermore, we compared the survivals of CAP1 deleted, wild-type, and overexpressed strains and found that Cap1p attenuated BE-initiated cell death, which was coherent with a higher mRNA level of the CAP1 gene. In addition, the mitochondrial membrane potential of C. albicans cells changed significantly ( p<0.001) upon BE treatment compared with control. Taken together, our results indicate that BE treatment induces apoptosis in C.albicans cells, and the apoptosis was associated with the breakdown of mitochondrial membrane potential. PMID:19734718

  14. Candida albicans Quorum Sensing Molecules Stimulate Mouse Macrophage Migration

    PubMed Central

    Hargarten, Jessica C.; Moore, Tyler C.; Petro, Thomas M.; Nickerson, Kenneth W.

    2015-01-01

    The polymorphic commensal fungus Candida albicans causes life-threatening disease via bloodstream and intra-abdominal infections in immunocompromised and transplant patients. Although host immune evasion is a common strategy used by successful human fungal pathogens, C. albicans provokes recognition by host immune cells less capable of destroying it. To accomplish this, C. albicans white cells secrete a low-molecular-weight chemoattractive stimulant(s) of macrophages, a phagocyte that they are able to survive within and eventually escape from. C. albicans opaque cells do not secrete this chemoattractive stimulant(s). We report here a physiological mechanism that contributes to the differences in the interaction of C. albicans white and opaque cells with macrophages. E,E-Farnesol, which is secreted by white cells only, is a potent stimulator of macrophage chemokinesis, whose activity is enhanced by yeast cell wall components and aromatic alcohols. E,E-farnesol results in up to an 8.5-fold increase in macrophage migration in vitro and promotes a 3-fold increase in the peritoneal infiltration of macrophages in vivo. Therefore, modulation of farnesol secretion to stimulate host immune recognition by macrophages may help explain why this commensal is such a successful pathogen. PMID:26195556

  15. A Photonic Crystal Protein Hydrogel Sensor for Candida albicans.

    PubMed

    Cai, Zhongyu; Kwak, Daniel H; Punihaole, David; Hong, Zhenmin; Velankar, Sachin S; Liu, Xinyu; Asher, Sanford A

    2015-10-26

    We report two-dimensional (2D) photonic crystal (PC) sensing materials that selectively detect Candida albicans (C. albicans). These sensors utilize Concanavalin A (Con A) protein hydrogels with a 2D PC embedded on the Con A protein hydrogel surface, that multivalently and selectively bind to mannan on the C. albicans cell surface to form crosslinks. The resulting crosslinks shrink the Con A protein hydrogel, reduce the 2D PC particle spacing, and blue-shift the light diffracted from the PC. The diffraction shifts can be visually monitored, measured with a spectrometer, or determined from the Debye diffraction ring diameter. Our unoptimized hydrogel sensor has a detection limit of around 32 CFU/mL for C. albicans. This sensor distinguishes between C. albicans and those microbes devoid of cell-surface mannan such as the gram-negative bacterium E. coli. This sensor provides a proof-of-concept for utilizing recognition between lectins and microbial cell surface carbohydrates to detect microorganisms in aqueous environments. PMID:26480336

  16. Candida albicans Quorum Sensing Molecules Stimulate Mouse Macrophage Migration.

    PubMed

    Hargarten, Jessica C; Moore, Tyler C; Petro, Thomas M; Nickerson, Kenneth W; Atkin, Audrey L

    2015-10-01

    The polymorphic commensal fungus Candida albicans causes life-threatening disease via bloodstream and intra-abdominal infections in immunocompromised and transplant patients. Although host immune evasion is a common strategy used by successful human fungal pathogens, C. albicans provokes recognition by host immune cells less capable of destroying it. To accomplish this, C. albicans white cells secrete a low-molecular-weight chemoattractive stimulant(s) of macrophages, a phagocyte that they are able to survive within and eventually escape from. C. albicans opaque cells do not secrete this chemoattractive stimulant(s). We report here a physiological mechanism that contributes to the differences in the interaction of C. albicans white and opaque cells with macrophages. E,E-Farnesol, which is secreted by white cells only, is a potent stimulator of macrophage chemokinesis, whose activity is enhanced by yeast cell wall components and aromatic alcohols. E,E-farnesol results in up to an 8.5-fold increase in macrophage migration in vitro and promotes a 3-fold increase in the peritoneal infiltration of macrophages in vivo. Therefore, modulation of farnesol secretion to stimulate host immune recognition by macrophages may help explain why this commensal is such a successful pathogen. PMID:26195556

  17. Oxidative stress responses in the human fungal pathogen, Candida albicans.

    PubMed

    Dantas, Alessandra da Silva; 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

  18. Candida species distribution, genotyping and virulence factors of Candida albicans isolated from the oral cavity of kidney transplant recipients of two geographic regions of Brazil

    PubMed Central

    2014-01-01

    Background Candida albicans is a diploid yeast that in some circumstances may cause oral or oropharyngeal infections. This investigation aimed to study the prevalence of Candida spp. and to analyze the ABC genotypes of 76 clinical isolates of C. albicans obtained from the oral cavity of kidney transplant patients from two distinct geographic regions of Brazil. Methods We typed 48 strains with ABC genotyping and Microsatelitte using primer M13 and tested three virulence factors in vitro: phospholipase activity, morphogenesis and the ability to evade from polymorphonuclear neutrophils phagocytosis. Results C. albicans was the most prevalent species (86.4%), followed by C. tropicalis (4.5%). C. albicans genotype A was the most prevalent (58 isolates; 76.4%), followed by genotype C (15 isolates; 19.7%) and genotype B (3 isolates; 3.9%). When Microsatellite technique with primer M13 was applied, 80% of the isolates from the South were placed within the same cluster. The majority of Genotype C strains were grouped together within two different clusters. Genotype C was considered more resistant to PMNs attack than genotypes A and B. Strains isolated from the South of Brazil showed also better ability to combat PMNs phagocytosis. Conclusions We found a high rate of C. albicans genotype C strains isolated from the oral cavity of this group of patients. This study characterized oral C. albicans strains isolated from kidney transplant recipients and will contribute to a better understanding of the pathogenesis of oral candidiasis. PMID:24628850

  19. Spaceflight enhances cell aggregation and random budding in Candida albicans.

    PubMed

    Crabbé, Aurélie; Nielsen-Preiss, Sheila M; Woolley, Christine M; Barrila, Jennifer; Buchanan, Kent; McCracken, James; Inglis, Diane O; Searles, Stephen C; Nelman-Gonzalez, Mayra A; Ott, C Mark; Wilson, James W; Pierson, Duane L; Stefanyshyn-Piper, Heidemarie M; Hyman, Linda E; Nickerson, Cheryl A

    2013-01-01

    This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 452 genes compared to synchronous ground controls, which represented 8.3% of the analyzed ORFs. Spaceflight-cultured C. albicans-induced genes involved in cell aggregation (similar to flocculation), which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p.) infection model was observed under the conditions of this study. Collectively, our data represent an important basis for the assessment of the risk that commensal flora could play during human spaceflight missions. Furthermore, since the low fluid

  20. Cellular Components Mediating Coadherence of Candida albicans and Fusobacterium nucleatum.

    PubMed

    Wu, T; Cen, L; Kaplan, C; Zhou, X; Lux, R; Shi, W; He, X

    2015-10-01

    Candida albicans is an opportunistic fungal pathogen found as part of the normal oral flora. It can be coisolated with Fusobacterium nucleatum, an opportunistic bacterial pathogen, from oral disease sites, such as those involved in refractory periodontitis and pulp necrosis. The physical coadherence between these 2 clinically important microbes has been well documented and suggested to play a role in facilitating their oral colonization and colocalization and contributing to polymicrobial pathogenesis. Previous studies indicated that the physical interaction between C. albicans and F. nucleatum was mediated by the carbohydrate components on the surface of C. albicans and the protein components on the Fusobaterium cell surface. However, the identities of the components involved still remain elusive. This study was aimed at identifying the genetic determinants involved in coaggregation between the 2 species. By screening a C. albicans SN152 mutant library and a panel of F. nucleatum 23726 outer membrane protein mutants, we identified FLO9, which encodes a putative adhesin-like cell wall mannoprotein of C. albicans and radD, an arginine-inhibitable adhesin-encoding gene in F. nucleatum that is involved in interspecies coadherence. Consistent with these findings, we demonstrated that the strong coaggregation between wild-type F. nucleatum 23726 and C. albicans SN152 in an in vitro assay could be greatly inhibited by arginine and mannose. Our study also suggested a complex multifaceted mechanism underlying physical interaction between C. albicans and F. nucleatum and for the first time revealed the identity of major genetic components involved in mediating the coaggregation. These observations provide useful knowledge for developing new targeted treatments for disrupting interactions between these 2 clinically relevant pathogens. PMID:26152186

  1. Molecular and Phenotypic Characterization of Genotypic Candida albicans Subgroups and Comparison with Candida dubliniensis and Candida stellatoidea

    PubMed Central

    McCullough, Michael J.; Clemons, Karl V.; Stevens, David A.

    1999-01-01

    There have been increased reports of the isolation of unusual genotypic groups of Candida albicans (groups C and D) based on a well-defined genotypic method; this method uses cellular DNA digested with the EcoRI enzyme and the restriction fragment length polymorphisms (RFLPs) generated by agarose gel electrophoresis. The aim of the present study was to use additional molecular tools to characterize these unusual strains and to compare them with authentic strains of C. dubliniensis, a recently delineated species, and type I C. stellatoidea. The RFLPs of PCR products generated from the intergenic transcribed spacer (ITS) region did not differentiate among C. albicans genotypes A, B, and C and type I C. stellatoidea. However, this method did differentiate the C. albicans genotype D strains, which were identical to C. dubliniensis. The RFLPs generated by HaeIII digestion of the PCR products of the V3 region of the 25S rRNA gene (rDNA) could differentiate the same groups as RFLP analysis of the PCR amplicon of the ITS region. C. albicans genotype B isolates have been shown to have a transposable intron in the 25S rDNA, whereas genotype A isolates do not; C. dubliniensis strains also have an intron that is larger than that in genotype B C. albicans strains but that is in the same location. PCR designed to span this region resulted in a single product for C. albicans genotype A (450 bp), B (840 bp), type 1 C. stellatoidea (840 bp), and C. dubliniensis (1,080 bp), whereas the C. albicans genotype C isolates had two major products (450 and 840 bp). All C. albicans genotype D isolates gave a PCR product identical to that given by C. dubliniensis. These results indicate that those strains previously designated C. albicans genotype D are in fact C. dubliniensis, that no differences were found between type 1 C. stellatoidea and C. albicans genotype B strains, and that the C. albicans genotype C strains appear to have the transposable intron incompletely inserted throughout the

  2. Total Protein Profile and Drug Resistance in Candida albicans Isolated from Clinical Samples

    PubMed Central

    Thawani, Vijay; Mehra, Arti

    2016-01-01

    This study was done to assess the antifungal susceptibility of clinical isolates of Candida albicans and to evaluate its total protein profile based on morphological difference on drug resistance. Hundred and twenty clinical isolates of C. albicans from various clinical specimens were tested for susceptibility against four antifungal agents, namely, fluconazole, itraconazole, amphotericin B, and ketoconazole. A significant increase of drug resistance in clinical isolates of C. albicans was observed. The study showed 50% fluconazole and itraconazole resistance at 32 μg mL−1 with a MIC50 and MIC90 values at 34 and 47 and 36 and 49 μg mL−1, respectively. All isolates were sensitive to amphotericin B and ketoconazole. The SDS-PAGE protein profile showed a prevalent band of ~52.5 kDa, indicating overexpression of gene in 72% strains with fluconazole resistance. Since the opportunistic infections of Candida spp. are increasing along with drug resistance, the total protein profile will help in understanding the evolutionary changes in drug resistance and also to characterize them. PMID:27478638

  3. Selective photoinactivation of Candida albicans in the non-vertebrate host infection model Galleria mellonella

    PubMed Central

    2013-01-01

    Background Candida spp. are recognized as a primary agent of severe fungal infection in immunocompromised patients, and are the fourth most common cause of bloodstream infections. Our study explores treatment with photodynamic therapy (PDT) as an innovative antimicrobial technology that employs a nontoxic dye, termed a photosensitizer (PS), followed by irradiation with harmless visible light. After photoactivation, the PS produces either singlet oxygen or other reactive oxygen species (ROS) that primarily react with the pathogen cell wall, promoting permeabilization of the membrane and cell death. The emergence of antifungal-resistant Candida strains has motivated the study of antimicrobial PDT (aPDT) as an alternative treatment of these infections. We employed the invertebrate wax moth Galleria mellonella as an in vivo model to study the effects of aPDT against C. albicans infection. The effects of aPDT combined with conventional antifungal drugs were also evaluated in G. mellonella. Results We verified that methylene blue-mediated aPDT prolonged the survival of C. albicans infected G. mellonella larvae. The fungal burden of G. mellonella hemolymph was reduced after aPDT in infected larvae. A fluconazole-resistant C. albicans strain was used to test the combination of aPDT and fluconazole. Administration of fluconazole either before or after exposing the larvae to aPDT significantly prolonged the survival of the larvae compared to either treatment alone. Conclusions G. mellonella is a useful in vivo model to evaluate aPDT as a treatment regimen for Candida infections. The data suggests that combined aPDT and antifungal therapy could be an alternative approach to antifungal-resistant Candida strains. PMID:24083556

  4. In vitro interactions between anidulafungin and nonsteroidal anti-inflammatory drugs on biofilms of Candida spp.

    PubMed

    Rosato, Antonio; Catalano, Alessia; Carocci, Alessia; Carrieri, Antonio; Carone, Addolorata; Caggiano, Giuseppina; Franchini, Carlo; Corbo, Filomena; Montagna, Maria Teresa

    2016-03-01

    Candida spp. are responsible for many biomaterial-related infections; they give rise to infective pathologies typically associated with biofilm formation. We recently reported that the echinocandin anidulafungin (ANF) showed a strong in vitro activity against both planktonic and biofilms cells. Herein, we report the antifungal activities of ANF alone and in association with some non-steroidal anti-inflammatory drugs (NSAIDs) against nine Candida strain biofilms: four Candida albicans, two Candida glabrata and three Candida guilliermondii. The activity of ANF was assessed using an in vitro microbiological model relevant for clinical practice. ANF proved oneself to be active against biofilms cells, and a clear-cut synergism was found against Candida species biofilms when ANF was used in combination with three NSAIDs: aspirin, diclofenac, ibuprofen. The positive synergism against Candida spp. of ANF in association with aspirin or the other NSAIDs proved to be a very effective antifungal treatment (FICI<0.5). These results may provide the starting point for new combination therapies of ANF with NSAIDs against Candida biofilm pathologies. PMID:26833243

  5. Bax-induced cell death in Candida albicans.

    PubMed

    De Smet, Kris; Eberhardt, Ines; Reekmans, Rieka; Contreras, Roland

    2004-12-01

    Bax is a pro-apoptotic member of the Bcl-2 family of proteins involved in the regulation of genetically programmed cell death in mammalian cells. It has been shown that heterologous expression of Bax in several yeast species, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Pichia pastoris, also induces cell death. In this study we investigated the effects of Bax expression in the pathogenic yeast Candida albicans. Cell death inducing expression of Bax required a synthetic BAX gene that was codon-optimized for expression in Candida albicans. Expression of this BAX gene resulted in growth inhibition and cell death. By fusing Bax with the yeast enhanced green fluorescent protein of Aequoria victoria, the cell death-inducing effect of Bax was increased due to reduced proteolytic degradation of Bax. Using this fusion protein we showed that, upon expression in C. albicans, Bax co-localizes with the mitochondria. Furthermore, we showed for the first time that expression of Bax in yeast causes the mitochondria, which are normally distributed throughout the cell, to cluster in the perinuclear region. PMID:15565645

  6. Structural characterization of CA1462, the Candida albicans thiamine pyrophosphokinase

    PubMed Central

    Santini, Sébastien; Monchois, Vincent; Mouz, Nicolas; Sigoillot, Cécile; Rousselle, Tristan; Claverie, Jean-Michel; Abergel, Chantal

    2008-01-01

    Background In search of new antifungal targets of potential interest for pharmaceutical companies, we initiated a comparative genomics study to identify the most promising protein-coding genes in fungal genomes. One criterion was the protein sequence conservation between reference pathogenic genomes. A second criterion was that the corresponding gene in Saccharomyces cerevisiae should be essential. Since thiamine pyrophosphate is an essential product involved in a variety of metabolic pathways, proteins responsible for its production satisfied these two criteria. Results We report the enzymatic characterization and the crystallographic structure of the Candida albicans Thiamine pyrophosphokinase. The protein was co-crystallized with thiamine or thiamine-PNP. Conclusion The presence of an inorganic phosphate in the crystallographic structure opposite the known AMP binding site relative to the thiamine moiety suggests that a second AMP molecule could be accommodated in the C. albicans structure. Together with the crystallographic structures of the enzyme/substrate complexes this suggests the existence of a secondary, less specific, nucleotide binding site in the Candida albicans thiamine pyrophosphokinase which could transiently serve during the release or the binding of ATP. The structures also highlight a conserved Glutamine residue (Q138) which could interact with the ATP α-phosphate and act as gatekeeper. Finally, the TPK/Thiamine-PNP complex is consistent with a one step mechanism of pyrophosphorylation. PMID:18652651

  7. Nanocapsules with glycerol monolaurate: Effects on Candida albicans biofilms.

    PubMed

    Lopes, Leonardo Quintana Soares; Santos, Cayane Genro; Vaucher, Rodrigo de Almeida; Raffin, Renata Platcheck; Santos, Roberto Christ Vianna

    2016-08-01

    Candida albicans does not only occur in the free living planktonic form but also grows in surface-attached biofilm communities. Moreover, these biofilms appear to be the most common lifestyle and are involved in the majority of human Candida infections. Nanoparticles can be used as an alternative to conventional antimicrobial agents and can also act as carriers for antibiotics and other drugs. In view of this, the aim of the study was develop, characterize and verify the anti-biofilm potential of GML Nanocapsules against C. albicans. The GML Nanocapsules showed mean diameter of 193.2 nm, polydispersion index of 0.044, zeta potential of -23.3 mV and pH 6.32. The microdilution assay showed MIC of 15.5 μg mL(-1) to GML Nanocapsules and 31.25 μg mL(-1) to GML. The anti-biofilm assay showed the significantly reduction of biomass of C. albicans biofilm treated with GML Nanocapsules while the GML does not exhibit effect. The kinetic assay demonstrated that at 48 h, the GML Nanocapsules reduce 94% of formed biofilm. The positive results suggest the promisor alternative for this public health problem that is biofilm infections. PMID:27241236

  8. Germ tube-specific antigens of Candida albicans cell walls

    SciTech Connect

    Sundstrom, P.R.

    1986-01-01

    Studies were performed to characterize the surface differences between blastospores and germ tubes of the pathogenic, dimorphic yeast, Candida albicans, and to identify components of yeast cells responsible for these differences. Investigation of surfaces differences of the two growth forms was facilitated by the production of rabbit antiserum prepared against Formalin-treated yeast possessing germ tubes. To prepare antiserum specific for germ tubes, this serum was adsorbed with stationary phase blastospores. Whereas the unadsorbed antiserum reacted with both blastospore and germ tube forms by immunofluorescence and Enzyme-Linked Immunosorbent Assay, the adsorbed antiserum did not react with blastospores but detected germ tube-specific antigens in hyphal forms. The differences between blastospores and germ tubes of Candida albicans, were further studied by comparing enzymatic digests of cell walls of both growth forms in radiolabeled organisms. Organisms were labeled either on the surface with /sup 125/I, or metabolically with (/sup 35/S) methionine or (/sup 3/H) mannose. Three-surface-located components (as shown by antibody adsorption and elution experiments) were precipitated from Zymolase digests. All three components were mannoproteins as shown by their ability to bind Concanavalin A, and to be labeled in protein labeling procedures, and two of these (200,000 and 155,000 molecular weight) were germ tube specific, as shown by their ability to be precipitated by germ tube-specific antiserum. Monoclonal antibodies were prepared to C. albicans, using blastospores bearing germ tubes as immunogen.

  9. A Human-Curated Annotation of the Candida albicans Genome

    PubMed Central

    Braun, Burkhard R; van het Hoog, Marco; d'Enfert, Christophe; Martchenko, Mikhail; Dungan, Jan; Kuo, Alan; Inglis, Diane O; Uhl, M. Andrew; Hogues, Hervé; Berriman, Matthew; Lorenz, Michael; Levitin, Anastasia; Oberholzer, Ursula; Bachewich, Catherine; Harcus, Doreen; Marcil, Anne; Dignard, Daniel; Iouk, Tatiana; Zito, Rosa; Frangeul, Lionel; Tekaia, Fredj; Rutherford, Kim; Wang, Edwin; Munro, Carol A; Bates, Steve; Gow, Neil A; Hoyer, Lois L; Köhler, Gerwald; Morschhäuser, Joachim; Newport, George; Znaidi, Sadri; Raymond, Martine; Turcotte, Bernard; Sherlock, Gavin; Costanzo, Maria; Ihmels, Jan; Berman, Judith; Sanglard, Dominique; Agabian, Nina; Mitchell, Aaron P; Johnson, Alexander D; Whiteway, Malcolm; Nantel, André

    2005-01-01

    Recent sequencing and assembly of the genome for the fungal pathogen Candida albicans used simple automated procedures for the identification of putative genes. We have reviewed the entire assembly, both by hand and with additional bioinformatic resources, to accurately map and describe 6,354 genes and to identify 246 genes whose original database entries contained sequencing errors (or possibly mutations) that affect their reading frame. Comparison with other fungal genomes permitted the identification of numerous fungus-specific genes that might be targeted for antifungal therapy. We also observed that, compared to other fungi, the protein-coding sequences in the C. albicans genome are especially rich in short sequence repeats. Finally, our improved annotation permitted a detailed analysis of several multigene families, and comparative genomic studies showed that C. albicans has a far greater catabolic range, encoding respiratory Complex 1, several novel oxidoreductases and ketone body degrading enzymes, malonyl-CoA and enoyl-CoA carriers, several novel amino acid degrading enzymes, a variety of secreted catabolic lipases and proteases, and numerous transporters to assimilate the resulting nutrients. The results of these efforts will ensure that the Candida research community has uniform and comprehensive genomic information for medical research as well as for future diagnostic and therapeutic applications. PMID:16103911

  10. Polyketide Glycosides from Bionectria ochroleuca Inhibit Candida albicans Biofilm Formation

    PubMed Central

    2015-01-01

    One of the challenges presented by Candida infections is that many of the isolates encountered in the clinic produce biofilms, which can decrease these pathogens’ susceptibilities to standard-of-care antibiotic therapies. Inhibitors of fungal biofilm formation offer a potential solution to counteracting some of the problems associated with Candida infections. A screening campaign utilizing samples from our fungal extract library revealed that a Bionectria ochroleuca isolate cultured on Cheerios breakfast cereal produced metabolites that blocked the in vitro formation of Candida albicans biofilms. A scale-up culture of the fungus was undertaken using mycobags (also known as mushroom bags or spawn bags), which afforded four known [TMC-151s C–F (1–4)] and three new [bionectriols B–D (5–7)] polyketide glycosides. All seven metabolites exhibited potent biofilm inhibition against C. albicans SC5314, as well as exerted synergistic antifungal activities in combination with amphotericin B. In this report, we describe the structure determination of the new metabolites, as well as compare the secondary metabolome profiles of fungi grown in flasks and mycobags. These studies demonstrate that mycobags offer a useful alternative to flask-based cultures for the preparative production of fungal secondary metabolites. PMID:25302529

  11. Evaluation of a rapid immunochromatographic assay for identification of Candida albicans and Candida dubliniensis.

    PubMed

    Marot-Leblond, Agnes; Grimaud, Linda; David, Sandrine; Sullivan, Derek J; Coleman, David C; Ponton, Jose; Robert, Raymond

    2004-11-01

    Candida dubliniensis was first established as a novel yeast species in 1995. It is particularly associated with recurrent episodes of oral candidosis in human immunodeficiency virus (HIV)-infected patients, but it has also been detected at other anatomical sites and at a low incidence level in non-HIV-infected patients. It shares so many phenotypic characteristics with C. albicans that it is easily misidentified as such. No rapid, simple, and commercial test that allows differentiation between C. dubliniensis and C. albicans has been developed, until now. Accurate species identification requires the use of genotype-based techniques that are not routinely available in most clinical microbiology diagnostic laboratories. The present study was designed to evaluate the efficiency of a new test (the immunochromatographic membrane [ICM] albi-dubli test; SR2B, Avrille, France) to differentiate between C. albicans and C. dubliniensis. The organisms evaluated were strains whose identities had previously been confirmed by PCR tests and freshly isolated clinical strains and included 58 C. albicans isolates, 60 C. dubliniensis isolates, and 82 isolates belonging to other species of yeast. The ICM albi-dubli test is based on the principle of immunochromatographic analysis and involves the use of two distinct monoclonal antibodies that recognize two unrelated epitopes expressed by both species or specific to only one species. The assay requires no complex instrumentation for analysis and can be recommended for routine use in clinical microbiology laboratories. Results are obtained within 2 h and 30 min and are easy to interpret. This evaluation demonstrated the good performance of this immunochromatographic test for C. albicans and C. dubliniensis isolated on Sabouraud dextrose agar, CHOROMagar Candida, and CandidaSelect, with sensitivities and specificities ranging from 93.1 to 100%. These parameters decreased, however, to 91.4% when the test was performed with yeast isolated

  12. Evaluation of a Rapid Immunochromatographic Assay for Identification of Candida albicans and Candida dubliniensis

    PubMed Central

    Marot-Leblond, Agnes; Grimaud, Linda; David, Sandrine; Sullivan, Derek J.; Coleman, David C.; Ponton, Jose; Robert, Raymond

    2004-01-01

    Candida dubliniensis was first established as a novel yeast species in 1995. It is particularly associated with recurrent episodes of oral candidosis in human immunodeficiency virus (HIV)-infected patients, but it has also been detected at other anatomical sites and at a low incidence level in non-HIV-infected patients. It shares so many phenotypic characteristics with C. albicans that it is easily misidentified as such. No rapid, simple, and commercial test that allows differentiation between C. dubliniensis and C. albicans has been developed, until now. Accurate species identification requires the use of genotype-based techniques that are not routinely available in most clinical microbiology diagnostic laboratories. The present study was designed to evaluate the efficiency of a new test (the immunochromatographic membrane [ICM] albi-dubli test; SR2B, Avrillé, France) to differentiate between C. albicans and C. dubliniensis. The organisms evaluated were strains whose identities had previously been confirmed by PCR tests and freshly isolated clinical strains and included 58 C. albicans isolates, 60 C. dubliniensis isolates, and 82 isolates belonging to other species of yeast. The ICM albi-dubli test is based on the principle of immunochromatographic analysis and involves the use of two distinct monoclonal antibodies that recognize two unrelated epitopes expressed by both species or specific to only one species. The assay requires no complex instrumentation for analysis and can be recommended for routine use in clinical microbiology laboratories. Results are obtained within 2 h and 30 min and are easy to interpret. This evaluation demonstrated the good performance of this immunochromatographic test for C. albicans and C. dubliniensis isolated on Sabouraud dextrose agar, CHOROMagar Candida, and CandidaSelect, with sensitivities and specificities ranging from 93.1 to 100%. These parameters decreased, however, to 91.4% when the test was performed with yeast isolated

  13. Coaggregation of Streptococcus sanguis and other streptococci with Candida albicans.

    PubMed Central

    Jenkinson, H F; Lala, H C; Shepherd, M G

    1990-01-01

    Thirteen strains of viridans group streptococci and two strains of other streptococci were tested for coaggregation with Candida albicans. Streptococcus sanguis strains generally exhibited low levels of adherence to 28 degrees C-grown exponential-phase yeast cells, but starvation of yeast cells for glucose at 37 degrees C (or at 28 degrees C) increased their coaggregating activity with these streptococci by at least tenfold. This was a property common to four C. albicans strains tested, two of which were able to form mycelia (6406 and MEN) and two of which were not (MM2002 and CA2). The expression of the coaggregation adhesin during yeast cell starvation was inhibited by addition of trichodermin or amphotericin B. The strains of S. sanguis, Streptococcus gordonii, and Streptococcus oralis tested for coaggregating activity encompassed a diverse range of physiological and morphological types, yet all exhibited saturable coaggregation with starved C. albicans cells. There was no correlation of cell surface hydrophobicity, of either yeast or streptococcal cells, with their abilities to coaggregate. Strains of Streptococcus anginosus also coaggregated with starved yeast cells; Streptococcus salivarius and Streptococcus pyogenes coaggregated to a lesser degree with C. albicans, and the coaggregation with S. pyogenes was not promoted by yeast cell starvation; Streptococcus mutans and Enterococcus faecalis did not coaggregate with yeast. The coaggregation reactions of S. sanguis and S. gordonii with C. albicans were inhibited by EDTA and by heat or protease treatment of the yeast cells and were not reversible by the addition of lactose or other simple sugars. These observations extend the range of intergeneric coaggregations that are known to occur between oral microbes and suggest that coaggregations of C. albicans with viridans group streptococci may be important for colonization of oral surfaces by the yeast. PMID:2182544

  14. Spaceflight Enhances Cell Aggregation and Random Budding in Candida albicans

    PubMed Central

    Woolley, Christine M.; Barrila, Jennifer; Buchanan, Kent; McCracken, James; Inglis, Diane O.; Searles, Stephen C.; Nelman-Gonzalez, Mayra A.; Ott, C. Mark; Wilson, James W.; Pierson, Duane L.; Stefanyshyn-Piper, Heidemarie M.; Hyman, Linda E.; Nickerson, Cheryl A.

    2013-01-01

    This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 452 genes compared to synchronous ground controls, which represented 8.3% of the analyzed ORFs. Spaceflight-cultured C. albicans–induced genes involved in cell aggregation (similar to flocculation), which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p.) infection model was observed under the conditions of this study. Collectively, our data represent an important basis for the assessment of the risk that commensal flora could play during human spaceflight missions. Furthermore, since the low fluid

  15. Factors Supporting Cysteine Tolerance and Sulfite Production in Candida albicans

    PubMed Central

    Hennicke, Florian; Grumbt, Maria; Lermann, Ulrich; Ueberschaar, Nico; Palige, Katja; Böttcher, Bettina; Jacobsen, Ilse D.; Staib, Claudia; Morschhäuser, Joachim; Monod, Michel; Hube, Bernhard; Hertweck, Christian

    2013-01-01

    The amino acid cysteine has long been known to be toxic at elevated levels for bacteria, fungi, and humans. However, mechanisms of cysteine tolerance in microbes remain largely obscure. Here we show that the human pathogenic yeast Candida albicans excretes sulfite when confronted with increasing cysteine concentrations. Mutant construction and phenotypic analysis revealed that sulfite formation from cysteine in C. albicans relies on cysteine dioxygenase Cdg1, an enzyme with similar functions in humans. Environmental cysteine induced not only the expression of the CDG1 gene in C. albicans, but also the expression of SSU1, encoding a putative sulfite efflux pump. Accordingly, the deletion of SSU1 resulted in enhanced sensitivity of the fungal cells to both cysteine and sulfite. To study the regulation of sulfite/cysteine tolerance in more detail, we screened a C. albicans library of transcription factor mutants in the presence of sulfite. This approach and subsequent independent mutant analysis identified the zinc cluster transcription factor Zcf2 to govern sulfite/cysteine tolerance, as well as cysteine-inducible SSU1 and CDG1 gene expression. cdg1Δ and ssu1Δ mutants displayed reduced hypha formation in the presence of cysteine, indicating a possible role of the newly proposed mechanisms of cysteine tolerance and sulfite secretion in the pathogenicity of C. albicans. Moreover, cdg1Δ mutants induced delayed mortality in a mouse model of disseminated infection. Since sulfite is toxic and a potent reducing agent, its production by C. albicans suggests diverse roles during host adaptation and pathogenicity. PMID:23417561

  16. Medical treatment of a pacemaker endocarditis due to Candida albicans and to Candida glabrata.

    PubMed

    Roger, P M; Boissy, C; Gari-Toussaint, M; Foucher, R; Mondain, V; Vandenbos, F; le Fichoux, Y; Michiels, J F; Dellamonica, P

    2000-09-01

    We describe a case of pacemaker infection due to two fungal species: Candida albicans and C. glabrata. Transthoracic echocardiography showed a large vegetation on the intraventricular wires. Because of severe underlying diseases, surgery was believed to be contraindicated. The patient was treated using high dose of fluconazole, resulting in clinical improvement and negative blood cultures. However, 2 months later, the patient underwent a fatal stroke. At autopsy, a large vegetation was found only all along the wires. Postmortem culture of the infected material was positive for both C. albicans and C. glabrata. PMID:11023765

  17. Zebrafish Egg Infection Model for Studying Candida albicans Adhesion Factors.

    PubMed

    Chen, Yin-Zhi; Yang, Yun-Liang; Chu, Wen-Li; You, May-Su; Lo, Hsiu-Jung

    2015-01-01

    Disseminated candidiasis is associated with 30-40% mortality in severely immunocompromised patients. Among the causal agents, Candida albicans is the dominant one. Various animal models have been developed for investigating gene functions in C. albicans. Zebrafish injection models have increasingly been applied in elucidating C. albicans pathogenesis because of the conserved immunity, prolific fecundity of the zebrafish and the low costs of care systems. In this study, we established a simple, noninvasive zebrafish egg bath infection model, defined its optimal conditions, and evaluated the model with various C. albicans mutant strains. The deletion of SAP6 did not have significant effect on the virulence. By contrast, the deletion of BCR1, CPH1, EFG1, or TEC1 significantly reduced the virulence under current conditions. Furthermore, all embryos survived when co-incubated with bcr1/bcr1, cph1/cph1 efg1/efg1, efg1/efg1, or tec1/tec1 mutant cells. The results indicated that our novel zebrafish model is time-saving and cost effective. PMID:26569623

  18. Disruption of Sphingolipid Biosynthesis Blocks Phagocytosis of Candida albicans.

    PubMed

    Tafesse, Fikadu G; Rashidfarrokhi, Ali; Schmidt, Florian I; Freinkman, Elizaveta; Dougan, Stephanie; Dougan, Michael; Esteban, Alexandre; Maruyama, Takeshi; Strijbis, Karin; Ploegh, Hidde L

    2015-10-01

    The ability of phagocytes to clear pathogens is an essential attribute of the innate immune response. The role of signaling lipid molecules such as phosphoinositides is well established, but the role of membrane sphingolipids in phagocytosis is largely unknown. Using a genetic approach and small molecule inhibitors, we show that phagocytosis of Candida albicans requires an intact sphingolipid biosynthetic pathway. Blockade of serine-palmitoyltransferase (SPT) and ceramide synthase-enzymes involved in sphingolipid biosynthesis- by myriocin and fumonisin B1, respectively, impaired phagocytosis by phagocytes. We used CRISPR/Cas9-mediated genome editing to generate Sptlc2-deficient DC2.4 dendritic cells, which lack serine palmitoyl transferase activity. Sptlc2-/- DC2.4 cells exhibited a stark defect in phagocytosis, were unable to bind fungal particles and failed to form a normal phagocytic cup to engulf C. albicans. Supplementing the growth media with GM1, the major ganglioside present at the cell surface, restored phagocytic activity of Sptlc2-/- DC2.4 cells. While overall membrane trafficking and endocytic pathways remained functional, Sptlc2-/- DC2.4 cells express reduced levels of the pattern recognition receptors Dectin-1 and TLR2 at the cell surface. Consistent with the in vitro data, compromised sphingolipid biosynthesis in mice sensitizes the animal to C. albicans infection. Sphingolipid biosynthesis is therefore critical for phagocytosis and in vivo clearance of C. albicans. PMID:26431038

  19. Enhanced antibody responses induced by Candida albicans in mice.

    PubMed

    Cutler, J E; Lloyd, R K

    1982-12-01

    Candida albicans may immunopotentiate antibody responses in mice to antigens unrelated to the fungus. This effect occurred best with cell-associated, rather than soluble, antigens. When dead yeasts, cell walls, or a water-soluble candidal polysaccharide were used, immunopotentiation was most dramatic when the antigen and fungal materials were given concomitantly via an intraperitoneal injection. However, mice infected with viable yeasts several days before antigen administration also developed heightened responses to the antigen. The mechanism of the C. albicans-induced adjuvanticity was not defined, but the effect seemed to correlate with induction of inflammation. The presence of C. albicans or other inflammatory agents in the peritoneal cavity caused a more rapid uptake of particulate antigen by the liver. The relationship between this event and immunopotentiation is not known. These studies demonstrate that C. albicans may have profound effects on host immune responses. Because immunological aberrations are commonly found in patients with candidiasis it may be important to determine whether some of these aberrations result from, rather than precede candidiasis. PMID:6185421

  20. Blood group glycolipids as epithelial cell receptors for Candida albicans.

    PubMed Central

    Cameron, B J; Douglas, L J

    1996-01-01

    The role of glycosphingolipids as possible epithelial cell receptors for Candida albicans was examined by investigating the binding of biotinylated yeasts to lipids extracted from human buccal epithelial cells and separated on thin-layer chromatograms. Binding was visualized by the addition of 125I-streptavidin followed by autoradiography. Five C. albicans strains thought from earlier work to have a requirement for fucose-containing receptors all bound to the same three components in the lipid extract. A parallel chromatogram overlaid with biotinylated Ulex europaeus lectin, which is a fucose-binding lectin with a specificity for the H blood group antigen, showed that two of these glycosphingolipids carried this antigenic determinant. Preparations of crude and purified adhesin (a protein with a size of 15.7 kDa which lacked cysteine residues) from one of the strains also bound to these same two components. The third glycosphingolipid, which bound whole cells but neither preparation of adhesin, was recognized by Helix pomatia lectin, indicating that it contained N-acetylgalactosamine, possibly in the form of the A blood group antigen. Overlay assays with a sixth strain of C. albicans (GDH 2023) revealed a completely different binding pattern of four receptors, each of which contained N-acetylglucosamine. These results confirm earlier predictions about the receptor specificity of the strains made on the basis of adhesion inhibition studies and indicate that blood group antigens can act as epithelial cell receptors for C. albicans. PMID:8641797

  1. Local Probiotic Therapy for Vaginal Candida albicans Infections.

    PubMed

    Kovachev, Stefan Miladinov; Vatcheva-Dobrevska, Rossitza Stefanova

    2015-03-01

    The high rate of vaginal Candida albicans recurrence is attributed to azole resistance rates as high as 15%. The aim of this study was to determine the clinical and microbiological efficacy of standard azole therapy for treatment of vaginal C. albicans infection alone and in combination with local probiotic as well as the effects on vaginal microbiota. This study included 436 women with vaginal candidiasis randomly assigned to two treatment groups. The first group, with 207 patients (12 dropouts), was administered 150 mg fluconazole and a single vaginal globule of fenticonazole (600 mg) on the same day. The second group of 209 patients (8 dropouts) followed the same treatment schedule; however, ten applications of a vaginal probiotic containing Lactobacillus acidophilus, L. rhamnosus, Streptococcus thermophilus, and L. delbrueckii subsp. bulgaricus were also administered beginning the fifth day after azole treatment. Microbiological analysis of the therapy efficacy in the first treatment group showed C. albicans resistance in over 30% of patients. Clinical complaints persisted after treatment administration in 79.7% (n = 165) of women in this group. Clinical complaints in the second group decreased to 31.1% (n = 65) and microbiological efficacy also improved among investigated parameters, from 93.7% (n = 193) to 95.2% (n = 198). The local application of probiotics after administration of combined azoles for treatment of vaginal C. albicans infections increases therapy efficacy and could prevent relapse. PMID:25362524

  2. Inhibition of Candida albicans virulence factors by novel levofloxacin derivatives.

    PubMed

    Shafreen, Raja Mohamed Beema; Raja Mohamed, Beema Shafreen; Muthamil, Subramanian; Subramanian, Muthamil; Pandian, Shunmugiah Karutha; Shunmugiah, Karutha Pandian

    2014-08-01

    Candida albicans is an important opportunistic fungal pathogen, responsible for biofilm associated infections in immunocompromised patients. The aim of the present study was to investigate the antibiofilm properties of novel levofloxacin derivatives on C. albicans biofilms. The levofloxacin derivatives at their Biofilm Inhibitory Concentrations (BIC) were able to inhibit the biofilms of C. albicans, the yeast-to-hyphal transition and were also able to disrupt their mature biofilms. Furthermore, Real-time PCR analysis showed that the expression of ergosterol biosynthesis pathway gene (ERG11) and the efflux pump-encoding genes (CDR1 and MDR1) was decreased upon treatment with the levofloxacin derivatives. The total ergosterol content quantified using UV spectrophotomer showed decrease in ergosterol in the presence of levofloxacin derivatives. Overall, levofloxacin derivatives (6a, 6c and 7d) are capable of inhibiting C. albicans virulence factors. Therefore, these compounds with potential therapeutic implications can be used as new strategy to treat biofilm-related candidal infections. PMID:24723295

  3. Transformations of inorganic mercury by Candida albicans and Saccharomyces cerevisiae

    SciTech Connect

    Yannai, S.; Berdicevsky, I.; Duek, L. )

    1991-01-01

    Saccharomyces cerevisiae and Candida albicans were incubated with 0.25, 0.5, or 0.75 {mu}g of Hg (as HgCl{sub 2}) per ml of Nelson's medium in the presence of trace amounts of oxygen at 28{degree}C for 12 days. Two control media were used, one without added Hg and one without yeast inoculum. Yeast cell growth was estimated after 1, 2, 3, and 8 days of incubation. The contents of organomercury in the system and of elemental mercury released from the media and collected in traps were determined at the end of the experiments. The results were as follows: (1) C. albicans was the more mercury-resistant species, but both yeast species failed to grown in the media containing 0.75 {mu}g of Hg per ml.; (2) The amounts of organomercury produced by the two species were proportional to the amount of HgCl{sub 2} added to the medium. In all cases C. albicans produced considerably larger amounts of methylmercury than S. cerevisiae; (3) The amounts of elemental Hg produced were inversely proportional to the HgCl{sub 2} level added in the case of S. cerevisiae but were all similar in the case of C. albicans;and (4) Neither organomercury nor elemental Hg was produced in any of the control media.

  4. Disruption of Sphingolipid Biosynthesis Blocks Phagocytosis of Candida albicans

    PubMed Central

    Schmidt, Florian I.; Freinkman, Elizaveta; Dougan, Stephanie; Dougan, Michael; Esteban, Alexandre; Maruyama, Takeshi; Strijbis, Karin; Ploegh, Hidde L.

    2015-01-01

    The ability of phagocytes to clear pathogens is an essential attribute of the innate immune response. The role of signaling lipid molecules such as phosphoinositides is well established, but the role of membrane sphingolipids in phagocytosis is largely unknown. Using a genetic approach and small molecule inhibitors, we show that phagocytosis of Candida albicans requires an intact sphingolipid biosynthetic pathway. Blockade of serine-palmitoyltransferase (SPT) and ceramide synthase-enzymes involved in sphingolipid biosynthesis- by myriocin and fumonisin B1, respectively, impaired phagocytosis by phagocytes. We used CRISPR/Cas9-mediated genome editing to generate Sptlc2-deficient DC2.4 dendritic cells, which lack serine palmitoyl transferase activity. Sptlc2-/- DC2.4 cells exhibited a stark defect in phagocytosis, were unable to bind fungal particles and failed to form a normal phagocytic cup to engulf C. albicans. Supplementing the growth media with GM1, the major ganglioside present at the cell surface, restored phagocytic activity of Sptlc2-/- DC2.4 cells. While overall membrane trafficking and endocytic pathways remained functional, Sptlc2-/- DC2.4 cells express reduced levels of the pattern recognition receptors Dectin-1 and TLR2 at the cell surface. Consistent with the in vitro data, compromised sphingolipid biosynthesis in mice sensitizes the animal to C. albicans infection. Sphingolipid biosynthesis is therefore critical for phagocytosis and in vivo clearance of C. albicans. PMID:26431038

  5. Two mechanisms of butenafine action in Candida albicans.

    PubMed Central

    Iwatani, W; Arika, T; Yamaguchi, H

    1993-01-01

    The mechanism of action of a new benzylamine antimycotic, butenafine hydrochloride, was studied in Candida albicans by using the thiocarbamate antimycotic tolnaftate as a reference drug. Butenafine completely inhibited the growth of a test strain of C. albicans at 25 micrograms/ml and was cidal at 50 micrograms/ml. Tolnaftate did not show any growth-inhibitory activity up to 100 micrograms/ml. Both butenafine and tolnaftate inhibited squalene epoxidation in C. albicans, with 50% inhibitory concentrations being 0.57 and 0.17 microgram/ml, respectively. Butenafine, but not tolnaftate, induced the release of appreciable amounts of Pi from C. albicans cells at 12.5 micrograms/ml. This effect of butenafine was augmented when the cells were pretreated with tolnaftate. The results suggest that the direct membrane-damaging effect of butenafine may play a major role in its anticandidal activity and that the drug-induced alteration in the cellular sterol composition renders the cell membrane more susceptible to the membrane-damaging effect of this drug. PMID:8494375

  6. Two mechanisms of butenafine action in Candida albicans.

    PubMed

    Iwatani, W; Arika, T; Yamaguchi, H

    1993-04-01

    The mechanism of action of a new benzylamine antimycotic, butenafine hydrochloride, was studied in Candida albicans by using the thiocarbamate antimycotic tolnaftate as a reference drug. Butenafine completely inhibited the growth of a test strain of C. albicans at 25 micrograms/ml and was cidal at 50 micrograms/ml. Tolnaftate did not show any growth-inhibitory activity up to 100 micrograms/ml. Both butenafine and tolnaftate inhibited squalene epoxidation in C. albicans, with 50% inhibitory concentrations being 0.57 and 0.17 microgram/ml, respectively. Butenafine, but not tolnaftate, induced the release of appreciable amounts of Pi from C. albicans cells at 12.5 micrograms/ml. This effect of butenafine was augmented when the cells were pretreated with tolnaftate. The results suggest that the direct membrane-damaging effect of butenafine may play a major role in its anticandidal activity and that the drug-induced alteration in the cellular sterol composition renders the cell membrane more susceptible to the membrane-damaging effect of this drug. PMID:8494375

  7. Effects of ambroxol on Candida albicans growth and biofilm formation.

    PubMed

    Rene, Hernandez-Delgadillo; José, Martínez-Sanmiguel Juan; Isela, Sánchez-Nájera Rosa; Claudio, Cabral-Romero

    2014-04-01

    Typically, the onset of candidiasis is characterised by the appearance of a biofilm of Candida albicans, which is associated with several diseases including oral candidiasis in young and elderly people. The objective of this work was to investigate the in vitro fungicidal activity as well as the antibiofilm activity of ambroxol (AMB) against C. albicans growth. In the present investigation, the fungicidal activity of AMB was established using the cell viability 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Also the minimum inhibitory concentration (MIC) of AMB required to inhibit the fungal growth was determined. Simultaneously, the antibiofilm activity of AMB was evaluated using fluorescence microscopy. The study revealed that 2 mg ml(-1) of AMB exhibited higher fungicidal activity than 3.3 mg ml(-1) of terbinafine, one of most common commercial antifungals. A MIC of 1 mg ml(-1) was determined for AMB to interfere with C. albicans growth. Furthermore, AMB was found to be effective in inhibiting the biofilm formation of C. albicans and exerted its fungicidal activity against the fungal cells interspersed in the preformed biofilm. The study suggests a potential role of the mucolytic agent, AMB, as an interesting therapeutic alternative in the treatment of oral candidiasis. PMID:24224742

  8. Deltamethrin Increases Candida albicans infection susceptibility in mice.

    PubMed

    Rehman, H; Mohan, A; Tabassum, H; Ahmad, F; Rahman, S; Parvez, S; Raisuddin, S

    2011-05-01

    Deltamethrin, an alpha-cyano type II synthetic pyrethroid insecticide, is used to control a wide range of insects on a variety of crops and vectors of diseases. Deltamethrin has been previously reported for its immunotoxic effects and therefore its exposure may affect the host resistance to infection and tumour challenge. Effect of exposure of deltamethrin on host resistance to Candida albicans infection was examined in Swiss albino mice. The objective of this study was to investigate the modulatory action of deltamethrin in C. albicans infected mice. The dose of deltamethrin was initially tested and selected from our previous study (18 mg/kg). Percentage of infection in deltamethrin treated animals increased faster when compared to that of the controls. Deltamethrin exposure along with C. albicans infection caused alteration of humoral immune response. The number of colony forming unit in liver and spleen were also found to be significantly increased in the treated group. The results from our present study suggest that deltamethrin exhibits an immunosuppressive effect and has a negative impact on host resistance to C. albicans infection. PMID:21272049

  9. Hydrophobic polyoxins are resistant to intracellular degradation in Candida albicans.

    PubMed Central

    Smith, H A; Shenbagamurthi, P; Naider, F; Kundu, B; Becker, J M

    1986-01-01

    Two novel polyoxins, N-epsilon-(octanoyl)-lysyl-uracil polyoxin C (Oct-Lys-UPOC) and N-gamma-(octyl)-glutaminyluracil polyoxin C (Oct-Gln-UPOC), were synthesized by reacting uracil polyoxin C with the appropriate amino acid p-nitrophenyl ester. Oct-Lys-UPOC and Oct-Gln-UPOC were strong inhibitors (Kis = 1.7 X 10(-6)M) of chitin synthetase from Candida albicans membrane preparations. In a permeabilized-cell assay, Oct-Gln-UPOC had a 10-fold-lower inhibitory activity toward chitin synthetase than did the Oct-Lys-UPOC analog. Both compounds were resistant to hydrolysis by a cell extract of C. albicans H317; however, Oct-Gln-UPOC was hydrolyzed with a half-life of 23 min by a permeabilized-cell preparation. Oct-Lys-UPOC was resistant to hydrolysis by permeabilized cells. Oct-Gln-UPOC and Oct-Lys-UPOC did not compete with the transport of peptides or uridine into the cell. At concentrations up to 2 mM these two new polyoxins were ineffective in the inhibition of cell growth or reduction of cell viability, but they induced aberrant morphologies in C. albicans at a concentration of 0.25 mM. These data suggest that polyoxins containing hydrophobic amino acids retain strong chitin synthetase inhibitory activity and are resistant to cellular hydrolysis. They provide the first example of effective synthetic chitin synthetase inhibitors which are stable inside C. albicans. PMID:3524423

  10. Th17 cells in immunity to Candida albicans

    PubMed Central

    Hernández-Santos, Nydiaris; Gaffen, Sarah L.

    2012-01-01

    Our understanding of immunity to fungal pathogens has advanced considerably in recent years. Particularly significant have been the parallel discoveries in the C-type lectin receptor family and the Th effector arms of immunity, especially Th17 cells and their signature cytokine IL-17. Many of these studies have focused on the most common human fungal pathogen Candida albicans, which is typically a commensal microbe in healthy individuals but causes various disease manifestations in immunocompromised hosts, ranging from mild mucosal infections to lethal disseminated disease. Here, we discuss emerging fundamental discoveries with C. albicans that have informed our overall molecular understanding of fungal immunity. In particular, we focus on the importance of pattern recognition receptor-mediated fungal recognition and subsequent IL-17 responses in host defense against mucosal candidiasis. In light of these recent advances, we also discuss the implications for anti-cytokine biologic therapy and vaccine development. PMID:22607796

  11. Lemongrass-Incorporated Tissue Conditioner Against Candida albicans Culture

    PubMed Central

    Amornvit, Pokpong; Srithavaj, Theerathavaj

    2014-01-01

    Background: Tissue conditioner is applied popularly with dental prosthesis during wound healing process but it becomes a reservoir of oral microbiota, especially Candida species after long-term usage. Several antifungal drugs have been mixed with this material to control fungal level. In this study, lemongrass essential oil was added into COE-COMFORT tissue conditioner before being determined for anti-Candida efficacy. Materials and Methods: Lemongrass (Cymbopogon citratus) essential oil was primarily determined for antifungal activity against C. albicans American type culture collection (ATCC) 10231 and MIC (minimum inhibitory concentration) value by agar disk diffusion and broth microdilution methods, respectively. COE-COMFORT tissue conditioner was prepared as recommended by the manufacturer after a fixed volume of the oil at its MIC or higher concentrations were mixed thoroughly in its liquid part. Antifungal efficacy of the tissue conditioner with/without herb was finally analyzed. Results: Lemongrass essential oil displayed potent antifungal activity against C. albicans ATCC 10231and its MIC value was 0.06% (v/v). Dissimilarly, the tissue conditioner containing the oil at MIC level did not cease the growth of the tested fungus. Both reference and clinical isolates of C. albicans were completely inhibited after exposed to the tissue conditioner containing at least 0.25% (v/v) of the oil (approximately 4-time MIC). The tissue conditioner without herb or with nystatin was employed as negative or positive control, respectively. Conclusion: COE-COMFORT tissue conditioner supplemented with lemongrass essential oil obviously demonstrated another desirable property as in vitro anti-Candida efficacy to minimize the risk of getting Candidal infection. PMID:25177638

  12. 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

  13. Interactions between amphotericin B and nitroimidazoles against Candida albicans.

    PubMed

    Cury, A E; Hirschfeld, M P

    1997-10-01

    This work proved that nitroimidazole antiprotozoal agents, such as metronidazole, ornidazole, secnidazole and tinidazole, in concentrations of up to 64 micrograms ml-1 did not present any antifungal activity against 17 strains of Candida albicans. The combination of each drug with amphotericin B showed the occurrence of variable interactions according to the studied strain. Promising results were observed based on synergistic and additive interactions of the polyene with the metronidazole; the inhibitory and lethal activities of the drugs were potentiated against all strains in concentrations reachable in vivo. PMID:9476486

  14. Susceptibility characterisation of Candida spp. to four essential oils.

    PubMed

    Rath, C C; Mohapatra, S

    2015-02-01

    In the present investigation, anti-Candida activity of four essential oils i.e. Black cumin (Nigella sativa), Curry leaf (Murraya koienigii), Ajwain (Trachiyspirum ammi), and Betel leaf (Piper betel) were screened against four human pathogenic species of Candida viz. Candida albicans, Candida tropicalis, Candida glabrata, and Candida parapsilosis. The minimum inhibitory concentration (MIC) values of the oils ranged between 15.62 and 250 μl/ml while studied through tube dilution method. The oils retained their anti-Candida activities even after heat treatment (at 45ΊC, 60ΊC, 100ΊC for 1 hour) and also on autoclaving. Both Ajwain and Black Cumin leaf oils showed better anti-Candida activity against Candida albicans, resulting in an irreversible damage to the cells. The anti-Candida activity of these essential oils could be attributable to the membrane inhibition mechanism. The activity of the oils is reported to be microbicidal (Candida-cidal). PMID:25657164

  15. Candida albicans Ultrastructure: Colonization and Invasion of Oral Epithelium

    PubMed Central

    Howlett, Julie A.; Squier, Christopher A.

    1980-01-01

    The colonization and invasion of various animal oral mucosae by Candida albicans were examined in an organ culture model. Scanning and transmission electron microscopy of the oral epithelium between 12 and 30 h after inoculation with the fungus revealed the morphological relationships between host and parasite. Examination of the fungi in thin sections showed five distinct layers in the cell wall of C. albicans within the epithelium, but changes were evident in the organization and definition of the outer cell wall layers in budding hyphae and in hyphae participating in colonization and invasion of the epithelial cells. Adherence of the fungus to the superficial cells of the oral mucosa appeared to involve intimate contact between the epithelial cell surface and the deeper layers of the fungal cell wall. During invasion a close seal was maintained between the invading hyphae and the surrounding epithelial cell envelope, there being no other evidence of damage to the host cell surface except at the site of entry. Within the epithelial cells there was only occasional loss of cytoplasmic components in the vicinity of the invading hyphae. These findings would suggest that enzymatic lysis associated with the invasive process is localized and that the mechanical support provided by surface adherence and the intimate association between the fungus and the epithelial cell envelope may permit growth of Candida on through the epithelium. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:6995338

  16. The ABCs of Candida albicans Multidrug Transporter Cdr1

    PubMed Central

    Banerjee, Atanu; Khandelwal, Nitesh Kumar; Dhamgaye, Sanjiveeni

    2015-01-01

    In the light of multidrug resistance (MDR) among pathogenic microbes and cancer cells, membrane transporters have gained profound clinical significance. Chemotherapeutic failure, by far, has been attributed mainly to the robust and diverse array of these proteins, which are omnipresent in every stratum of the living world. Candida albicans, one of the major fungal pathogens affecting immunocompromised patients, also develops MDR during the course of chemotherapy. The pivotal membrane transporters that C. albicans has exploited as one of the strategies to develop MDR belongs to either the ATP binding cassette (ABC) or the major facilitator superfamily (MFS) class of proteins. The ABC transporter Candida drug resistance 1 protein (Cdr1p) is a major player among these transporters that enables the pathogen to outplay the battery of antifungals encountered by it. The promiscuous Cdr1 protein fulfills the quintessential need of a model to study molecular mechanisms of multidrug transporter regulation and structure-function analyses of asymmetric ABC transporters. In this review, we cover the highlights of two decades of research on Cdr1p that has provided a platform to study its structure-function relationships and regulatory circuitry for a better understanding of MDR not only in yeast but also in other organisms. PMID:26407965

  17. Chloroquine sensitizes biofilms of Candida albicans to antifungal azoles.

    PubMed

    Shinde, Ravikumar Bapurao; Raut, Jayant Shankar; Chauhan, Nitin Mahendra; Karuppayil, Sankunny Mohan

    2013-01-01

    Biofilms formed by Candida albicans, a human pathogen, are known to be resistant to different antifungal agents. Novel strategies to combat the biofilm associated Candida infections like multiple drug therapy are being explored. In this study, potential of chloroquine to be a partner drug in combination with four antifungal agents, namely fluconazole, voriconazole, amphotericin B, and caspofungin, was explored against biofilms of C. albicans. Activity of various concentrations of chloroquine in combination with a particular antifungal drug was analyzed in a checkerboard format. Growth of biofilm in presence of drugs was analyzed by XTT-assay, in terms of relative metabolic activity compared to that of drug free control. Results obtained by XTT-metabolic assay were confirmed by scanning electron microscopy. The interactions between chloroquine and four antifungal drugs were determined by calculating fractional inhibitory concentration indices. Azole resistance in biofilms was reverted significantly (p<0.05) in presence of 250μg/mL of chloroquine, which resulted in inhibition of biofilms at very low concentrations of antifungal drugs. No significant alteration in the sensitivity of biofilms to caspofungin and amphotericin B was evident in combination with chloroquine. This study for the first time indicates that chloroquine potentiates anti-biofilm activity of fluconazole and voriconazole. PMID:23602464

  18. The ABCs of Candida albicans Multidrug Transporter Cdr1.

    PubMed

    Prasad, Rajendra; Banerjee, Atanu; Khandelwal, Nitesh Kumar; Dhamgaye, Sanjiveeni

    2015-12-01

    In the light of multidrug resistance (MDR) among pathogenic microbes and cancer cells, membrane transporters have gained profound clinical significance. Chemotherapeutic failure, by far, has been attributed mainly to the robust and diverse array of these proteins, which are omnipresent in every stratum of the living world. Candida albicans, one of the major fungal pathogens affecting immunocompromised patients, also develops MDR during the course of chemotherapy. The pivotal membrane transporters that C. albicans has exploited as one of the strategies to develop MDR belongs to either the ATP binding cassette (ABC) or the major facilitator superfamily (MFS) class of proteins. The ABC transporter Candida drug resistance 1 protein (Cdr1p) is a major player among these transporters that enables the pathogen to outplay the battery of antifungals encountered by it. The promiscuous Cdr1 protein fulfills the quintessential need of a model to study molecular mechanisms of multidrug transporter regulation and structure-function analyses of asymmetric ABC transporters. In this review, we cover the highlights of two decades of research on Cdr1p that has provided a platform to study its structure-function relationships and regulatory circuitry for a better understanding of MDR not only in yeast but also in other organisms. PMID:26407965

  19. SOME CYTOLOGICAL AND PATHOGENIC PROPERTIES OF SPHEROPLASTS OF CANDIDA ALBICANS

    PubMed Central

    Kobayashi, George S.; Friedman, Lorraine; Kofroth, Judith F.

    1964-01-01

    Kobayashi, George S. (Tulane University, New Orleans, La.), Lorraine Friedman, and Judith F. Kofroth. Some cytological and pathogenic properties of spheroplasts of Candida albicans. J. Bacteriol. 88:795–801. 1964.—Spheroplasts of Candida albicans were prepared by use of an enzymatic mixture from the digestive tract of the snail Helix pomatia. Untreated cells exhibited well-defined cell walls, whereas such structures were absent from spheroplasts. The intravenous inoculation of either spheroplasts or intact cells into rabbits produced a fever which was apparent within 30 min, the “immediate” fever response characteristic of microbial endotoxin. Cell-wall fragments of enzyme-treated cells did not induce a convincing pyrogenic response. When the inoculum was viable, body temperatures did not return to normal but remained elevated until death of the animal 1 or more days later, exhibiting the “delayed” fever of infection. The gross pathological picture in animals succumbing to infection by viable spheroplasts was similar to that obtained with untreated yeast cells. Images PMID:14208520

  20. Ultrastructural Analysis of Candida albicans When Exposed to Silver Nanoparticles

    PubMed Central

    Vazquez-Muñoz, Roberto; Avalos-Borja, Miguel; Castro-Longoria, Ernestina

    2014-01-01

    Candida albicans is the most common fungal pathogen in humans, and recently some studies have reported the antifungal activity of silver nanoparticles (AgNPs) against some Candida species. However, ultrastructural analyses on the interaction of AgNPs with these microorganisms have not been reported. In this work we evaluated the effect of AgNPs on C. albicans, and the minimum inhibitory concentration (MIC) was found to have a fungicidal effect. The IC50 was also determined, and the use of AgNPs with fluconazole (FLC), a fungistatic drug, reduced cell proliferation. In order to understand how AgNPs interact with living cells, the ultrastructural distribution of AgNPs in this fungus was determined. Transmission electron microscopy (TEM) analysis revealed a high accumulation of AgNPs outside the cells but also smaller nanoparticles (NPs) localized throughout the cytoplasm. Energy dispersive spectroscopy (EDS) analysis confirmed the presence of intracellular silver. From our results it is assumed that AgNPs used in this study do not penetrate the cell, but instead release silver ions that infiltrate into the cell leading to the formation of NPs through reduction by organic compounds present in the cell wall and cytoplasm. PMID:25290909

  1. Candida albicans repetitive elements display epigenetic diversity and plasticity

    PubMed Central

    Freire-Benéitez, Verónica; Price, R. Jordan; Tarrant, Daniel; Berman, Judith; Buscaino, Alessia

    2016-01-01

    Transcriptionally silent heterochromatin is associated with repetitive DNA. It is poorly understood whether and how heterochromatin differs between different organisms and whether its structure can be remodelled in response to environmental signals. Here, we address this question by analysing the chromatin state associated with DNA repeats in the human fungal pathogen Candida albicans. Our analyses indicate that, contrary to model systems, each type of repetitive element is assembled into a distinct chromatin state. Classical Sir2-dependent hypoacetylated and hypomethylated chromatin is associated with the rDNA locus while telomeric regions are assembled into a weak heterochromatin that is only mildly hypoacetylated and hypomethylated. Major Repeat Sequences, a class of tandem repeats, are assembled into an intermediate chromatin state bearing features of both euchromatin and heterochromatin. Marker gene silencing assays and genome-wide RNA sequencing reveals that C. albicans heterochromatin represses expression of repeat-associated coding and non-coding RNAs. We find that telomeric heterochromatin is dynamic and remodelled upon an environmental change. Weak heterochromatin is associated with telomeres at 30 °C, while robust heterochromatin is assembled over these regions at 39 °C, a temperature mimicking moderate fever in the host. Thus in C. albicans, differential chromatin states controls gene expression and epigenetic plasticity is linked to adaptation. PMID:26971880

  2. 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

  3. Distribution of Candida albicans genotypes among family members

    NASA Technical Reports Server (NTRS)

    Mehta, S. K.; Stevens, D. A.; Mishra, S. K.; Feroze, F.; Pierson, D. L.

    1999-01-01

    Thirty-three families (71 subjects) were screened for the presence of Candida albicans in mouthwash or stool specimens; 12 families (28 subjects) were culture-positive for this yeast. An enrichment procedure provided a twofold increase in the recovery of C. albicans from mouthwash specimens. Nine of the twelve culture-positive families had two positive members each, two families had three positive members each, and one family had four positive members. Genetic profiles were obtained by three methods: pulsed-field gel electrophoresis; restriction endonuclease analysis, and random amplification of polymorphic DNA analysis. DNA fingerprinting of C. albicans isolated from one body site three consecutive times revealed that each of the 12 families carried a distinct genotype. No two families shared the same strain, and two or more members of a family commonly shared the same strain. Intrafamily genotypic identity (i.e., each member within the family harbored the same strain) was demonstrated in six families. Genotypes of isolates from husband and wife differed from one another in five families. All three methods were satisfactory in determining genotypes; however, we concluded that restriction endonuclease analysis provided adequate resolving power.

  4. Fluconazole Assists Berberine To Kill Fluconazole-Resistant Candida albicans

    PubMed Central

    Li, De-Dong; Xu, Yi; Zhang, Da-Zhi; Quan, Hua; Mylonakis, Eleftherios; Hu, Dan-Dan; Li, Ming-Bang; Zhao, Lan-Xue; Zhu, Liang-Hua

    2013-01-01

    It was found in our previous study that berberine (BBR) and fluconazole (FLC) used concomitantly exhibited a synergism against FLC-resistant Candida albicans in vitro. The aim of the present study was to clarify how BBR and FLC worked synergistically and the underlying mechanism. Antifungal time-kill curves indicated that the synergistic effect of the two drugs was BBR dose dependent rather than FLC dose dependent. In addition, we found that BBR accumulated in C. albicans cells, especially in the nucleus, and resulted in cell cycle arrest and significant change in the transcription of cell cycle-related genes. Besides BBR, other DNA intercalators, including methylene blue, sanguinarine, and acridine orange, were all found to synergize with FLC against FLC-resistant C. albicans. Detection of intracellular BBR accumulation by fluorescence measurement showed that FLC played a role in increasing intracellular BBR concentration, probably due to its effect in disrupting the fungal cell membrane. Similar to the case with FLC, other antifungal agents acting on the cell membrane were able to synergize with BBR. Interestingly, we found that the efflux of intracellular BBR was FLC independent but strongly glucose dependent and associated with the drug efflux pump Cdr2p. These results suggest that BBR plays a major antifungal role in the synergism of FLC and BBR, while FLC plays a role in increasing the intracellular BBR concentration. PMID:24060867

  5. High Recovery Rate of Non-albicans Candida Species Isolated From Burn Patients With Candidemia in Iran

    PubMed Central

    Lotfi, Nazanin; Shokohi, Tahereh; Nouranibaladezaei, Seyed Zahra; Nasrolahi Omran, Ayatollah; Kondori, Nahid

    2015-01-01

    Background: Blood stream infections (BSIs) are major causes of morbidity and mortality in burn patients. Microorganisms responsible for BSI are generally bacteria; however, Candida spp. are the infection agents in as many as 8% of all cases. Burn wound colonization and infections are generally the first steps to systemic infection. Candidemia in burn patients has been associated with high mortality and a prolonged hospital stay. Objectives: Candidemia in burn patients has been defined as a preterminal event, leading to high morbidity and mortality rates among these patients. The aim of this study was to establish the incidence of candidemia in burn patients in Iran. Patients and Methods: We consecutively collected 405 blood samples from 113 burn patients. The yeast isolates were identified to the species level using conventional procedures. In vitro antifungal susceptibility of the Candida isolates to amphotericin B, fluconazole, voriconazole and caspofungin was performed using the Etest. Results: Twenty-seven samples (6.7%) of the blood cultures from 13 patients (12%) were positive for Candida species. Candida parapsilosis (38%) and C. tropicalis (38%) were the most commonly found Candida species, followed by C. albicans (15%) and C. guilliermondii (15%) in the patients. The incidence of candidemia was significantly correlated with increased duration of hospitalization, increased time of stay in the intensive care unit, and higher mortality. The antifungal susceptibility tests demonstrated that amphotericin B and voriconazole had the lowest minimum inhibitory concentrations (MICs) against Candida spp. Conclusions: Non-albicans Candida should be considered as significant pathogens in burned patients with candidemia. PMID:26587207

  6. Systematic Analysis of the Lysine Acetylome in Candida albicans.

    PubMed

    Zhou, Xiaowei; Qian, Guanyu; Yi, Xingling; Li, Xiaofang; Liu, Weida

    2016-08-01

    Candida albicans (C. albicans) is a worldwide cause of fungal infectious diseases. As a general post-translational modification (PTM), lysine acetylation of proteins play an important regulatory role in almost every cell. In our research, we used a high-resolution proteomic technique (LC-MS/MS) to present the comprehensive analysis of the acetylome in C. albicans. In general, we detected 477 acetylated proteins among all 9038 proteins (5.28%) in C. albicans, which had 1073 specific acetylated sites. The bioinformatics analysis of the acetylome showed a significant role in the regulation of metabolism. To be more precise, proteins involved in carbon metabolism and biosynthesis were the underlying objectives of acetylation. Besides, through the study of the acetylome, we found a universal rule in acetylated motifs: the +4, +5, or +6 position, which is an alkaline residue with a long side chain (K or R), and the +1 or +2 position, which is a residue with a long side chain (Y, H, W, or F). To the best of our knowledge, all screening acetylated histone sites of this study have not been previously reported. Moreover, protein-protein interaction network (PPI) study demonstrated that a variety of connections in glycolysis/gluconeogenesis, oxidative phosphorylation, and the ribosome were modulated by acetylation and phosphorylation, but the phosphorylated proteins in oxidative phosphorylation PPI network were not abundant, which indicated that acetylation may have a more significant effect than phosphorylation on oxidative phosphorylation. This is the first study of the acetylome in human pathogenic fungi, providing an important starting point for the in-depth discovery of the functional analysis of acetylated proteins in such fungal pathogens. PMID:27297460

  7. Mitochondrial two-component signaling systems in Candida albicans.

    PubMed

    Mavrianos, John; Berkow, Elizabeth L; Desai, Chirayu; Pandey, Alok; Batish, Mona; Rabadi, Marissa J; Barker, Katherine S; Pain, Debkumar; Rogers, P David; Eugenin, Eliseo A; Chauhan, Neeraj

    2013-06-01

    Two-component signal transduction pathways are one of the primary means by which microorganisms respond to environmental signals. These signaling cascades originated in prokaryotes and were inherited by eukaryotes via endosymbiotic lateral gene transfer from ancestral cyanobacteria. We report here that the nuclear genome of the pathogenic fungus Candida albicans contains elements of a two-component signaling pathway that seem to be targeted to the mitochondria. The C. albicans two-component response regulator protein Srr1 (stress response regulator 1) contains a mitochondrial targeting sequence at the N terminus, and fluorescence microscopy reveals mitochondrial localization of green fluorescent protein-tagged Srr1. Moreover, phylogenetic analysis indicates that C. albicans Srr1 is more closely related to histidine kinases and response regulators found in marine bacteria than are other two-component proteins present in the fungi. These data suggest conservation of this protein during the evolutionary transition from endosymbiont to a subcellular organelle. We used microarray analysis to determine whether the phenotypes observed with a srr1Δ/Δ mutant could be correlated with gene transcriptional changes. The expression of mitochondrial genes was altered in the srr1Δ/Δ null mutant in comparison to their expression in the wild type. Furthermore, apoptosis increased significantly in the srr1Δ/Δ mutant strain compared to the level of apoptosis in the wild type, suggesting the activation of a mitochondrion-dependent apoptotic cell death pathway in the srr1Δ/Δ mutant. Collectively, this study shows for the first time that a lower eukaryote like C. albicans possesses a two-component response regulator protein that has survived in mitochondria and regulates a subset of genes whose functions are associated with the oxidative stress response and programmed cell death (apoptosis). PMID:23584995

  8. Oxidant-specific regulation of protein synthesis in Candida albicans.

    PubMed

    Sundaram, Arunkumar; Grant, Chris M

    2014-06-01

    Eukaryotic cells typically respond to stress conditions by inhibiting global protein synthesis. The initiation phase is the main target of regulation and represents a key control point for eukaryotic gene expression. In Saccharomyces cerevisiae and mammalian cells this is achieved by phosphorylation of eukaryotic initiation factor 2 (eIF2α). We have examined how the fungal pathogen Candida albicans responds to oxidative stress conditions and show that oxidants including hydrogen peroxide, the heavy metal cadmium and the thiol oxidant diamide inhibit translation initiation. The inhibition in response to hydrogen peroxide and cadmium largely depends on phosphorylation of eIF2α since minimal inhibition is observed in a gcn2 mutant. In contrast, translation initiation is inhibited in a Gcn2-independent manner in response to diamide. Our data indicate that all three oxidants inhibit growth of C. albicans in a dose-dependent manner, however, loss of GCN2 does not improve growth in the presence of hydrogen peroxide or cadmium. Examination of translational activity indicates that these oxidants inhibit translation at a post-initiation phase which may account for the growth inhibition in a gcn2 mutant. As well as inhibiting global translation initiation, phosphorylation of eIF2α also enhances expression of the GCN4 mRNA in yeast via a well-known translational control mechanism. We show that C. albicans GCN4 is similarly induced in response to oxidative stress conditions and Gcn4 is specifically required for hydrogen peroxide tolerance. Thus, the response of C. albicans to oxidative stress is mediated by oxidant-specific regulation of translation initiation and we discuss our findings in comparison to other eukaryotes including the yeast S. cerevisiae. PMID:24699161

  9. Mitochondrial Two-Component Signaling Systems in Candida albicans

    PubMed Central

    Mavrianos, John; Berkow, Elizabeth L.; Desai, Chirayu; Pandey, Alok; Batish, Mona; Rabadi, Marissa J.; Barker, Katherine S.; Pain, Debkumar; Rogers, P. David; Eugenin, Eliseo A.

    2013-01-01

    Two-component signal transduction pathways are one of the primary means by which microorganisms respond to environmental signals. These signaling cascades originated in prokaryotes and were inherited by eukaryotes via endosymbiotic lateral gene transfer from ancestral cyanobacteria. We report here that the nuclear genome of the pathogenic fungus Candida albicans contains elements of a two-component signaling pathway that seem to be targeted to the mitochondria. The C. albicans two-component response regulator protein Srr1 (stress response regulator 1) contains a mitochondrial targeting sequence at the N terminus, and fluorescence microscopy reveals mitochondrial localization of green fluorescent protein-tagged Srr1. Moreover, phylogenetic analysis indicates that C. albicans Srr1 is more closely related to histidine kinases and response regulators found in marine bacteria than are other two-component proteins present in the fungi. These data suggest conservation of this protein during the evolutionary transition from endosymbiont to a subcellular organelle. We used microarray analysis to determine whether the phenotypes observed with a srr1Δ/Δ mutant could be correlated with gene transcriptional changes. The expression of mitochondrial genes was altered in the srr1Δ/Δ null mutant in comparison to their expression in the wild type. Furthermore, apoptosis increased significantly in the srr1Δ/Δ mutant strain compared to the level of apoptosis in the wild type, suggesting the activation of a mitochondrion-dependent apoptotic cell death pathway in the srr1Δ/Δ mutant. Collectively, this study shows for the first time that a lower eukaryote like C. albicans possesses a two-component response regulator protein that has survived in mitochondria and regulates a subset of genes whose functions are associated with the oxidative stress response and programmed cell death (apoptosis). PMID:23584995

  10. Binding of the extracellular matrix component entactin to Candida albicans.

    PubMed Central

    López-Ribot, J L; Chaffin, W L

    1994-01-01

    We have investigated the interaction between Candida albicans and entactin, a recently characterized glycoprotein present in the extracellular matrix, especially in the basement membrane. Organisms of both the yeast and the hyphal morphologies of the fungus had the ability to bind recombinant entactin, as detected by an indirect immunofluorescence assay. Material present in the 2-mercaptoethanol cell wall extracts from both C. albicans growth forms was capable of binding to immobilized recombinant entactin in a dose-dependent manner. Binding to entactin was approximately twice that observed for laminin. Binding of an extract component(s) to entactin was partially inhibited by an Arg-Gly-Asp-Ser peptide. A polyclonal antientactin antiserum, as well as a pooled antiserum preparation raised against components present in different C. albicans cell wall extracts, completely or almost completely abolished binding. The existence of morphology-specific receptor-like molecules which bind to different domains of the entactin molecule was ruled out in a competition binding assay. The entactin-binding material(s) in the cell wall also displayed some ability to bind laminin and fibronectin, since preadsorption in the presence of these extracellular matrix components resulted in reduction of binding to entactin. Moieties with a molecular mass of approximately 25, 44, and 65 kDa present in the 2-mercaptoethanol cell wall extracts from both blastoconidia and germ tubes were detected in a ligand affinity blotting experiment as having the ability to bind entactin. Interactions between C. albicans and entactin could be important in mediating adhesion of the fungus to the host tissues and may play a role in the establishment of the disseminated form of the disease. Images PMID:7927722

  11. In Vitro Activity of Tea Tree Oil Vaginal Suppositories against Candida spp. and Probiotic Vaginal Microbiota.

    PubMed

    Di Vito, Maura; Mattarelli, Paola; Modesto, Monica; Girolamo, Antonietta; Ballardini, Milva; Tamburro, Annunziata; Meledandri, Marcello; Mondello, Francesca

    2015-10-01

    The aim of this work is to evaluate the in vitro microbicidal activity of vaginal suppositories (VS) containing tea tree oil (TTO-VS) towards Candida spp. and vaginal probiotics. A total of 20 Candida spp. strains, taken from patients with vaginitis and from an established type collection, including reference strains, were analysed by using the CLSI microdilution method. To study the action of VS towards the beneficial vaginal microbiota, the sensitivity of Bifidobacterium animalis subsp. lactis (DSM 10140) and Lactobacillus spp. (Lactobacillus casei R-215 and Lactobacillus acidophilus R-52) was tested. Both TTO-VS and TTO showed fungicidal activity against all strains of Candida spp. whereas placebo-VS or the Aloe gel used as controls were ineffective. The study of fractional fungicidal concentrations (FFC) showed synergistic interaction with the association between Amphotericin B and TTO (0.25 to 0.08 µg/ml, respectively) against Candida albicans. Instead, the probiotics were only affected by TTO concentration ≥ 4% v/v, while, at concentrations < 2% v/v, they remained viable. TTO-VS exhibits, in vitro, a selective fungicidal action, slightly affecting only the Bifidobacteriun animalis strain growth belonging to the vaginal microbiota. In vivo studies are needed to confirm the efficacy to prevent acute or recurrent vaginal candidiasis. PMID:26235937

  12. Antimicrobial effects of three tropical plant extracts on Staphylococcus aureus, Escherichia coli and Candida albicans.

    PubMed

    Okigbo, R N; Mmeka, E C

    2008-01-01

    Antimicrobial activities of the leaf extracts of Cymbopogon citatrus (lemongrass) and Vernonia amygdalina (bitter leaf) and the seed extracts of Garcinia kola (bitter kola) were carried out. G. kola had effect only on Staphylococcus aureus and Escherichia coli with no inhibition on Candida albicans. Ethanol, cold water and hot water extracts of Vernonia amygdalina and Cymbopogon citratus showed inhibition on the three organism but G. kola ethanol, cold water and hot water extracts only inhibited S. aureus and E. coli with no inhibition on Candida albicans. The organism's susceptibility varied with more inhibition to S. aureus and least to Candida albicans. PMID:20161941

  13. In vitro activity of essential oils extracted from plants used as spices against fluconazole-resistant and fluconazole-susceptible Candida spp.

    PubMed

    Pozzatti, Patrícia; Scheid, Liliane Alves; Spader, Tatiana Borba; Atayde, Margareth Linde; Santurio, Janio Morais; Alves, Sydney Hartz

    2008-11-01

    In the present study, the antifungal activity of selected essential oils obtained from plants used as spices was evaluated against both fluconazole-resistant and fluconazole-susceptible Candida spp. The Candida species studied were Candida albicans, Candida dubliniensis, Candida tropicalis, Candida glabrata, and Candida krusei. For comparison purposes, they were arranged in groups as C. albicans, C. dubliniensis, and Candida non-albicans. The essential oils were obtained from Cinnamomum zeylanicum Breyn, Lippia graveolens HBK, Ocimum basilicum L., Origanum vulgare L., Rosmarinus officinalis L., Salvia officinalis L., Thymus vulgaris L., and Zingiber officinale. The susceptibility tests were based on the M27-A2 methodology. The chemical composition of the essential oils was obtained by gas chromatography-mass spectroscopy and by retention indices. The results showed that cinnamon, Mexican oregano, oregano, thyme, and ginger essential oils have different levels of antifungal activity. Oregano and ginger essential oils were found to be the most and the least efficient, respectively. The main finding was that the susceptibilities of fluconazole-resistant C. albicans, C. dubliniensis, and Candida non-albicans to Mexican oregano, oregano, thyme, and ginger essential oils were higher than those of the fluconazole-susceptible yeasts (P<0.05). In contrast, fluconazole-resistant C. albicans and Candida non-albicans were less susceptible to cinnamon essential oil than their fluconazole-susceptible counterparts (P<0.05). A relationship between the yeasts' susceptibilities and the chemical composition of the essential oils studied was apparent when these 2 parameters were compared. Finally, basil, rosemary, and sage essential oils did not show antifungal activity against Candida isolates at the tested concentrations. PMID:18997851

  14. Propargyl-Linked Antifolates are Dual Inhibitors of Candida albicans and Candida glabrata

    PubMed Central

    2015-01-01

    Species of Candida, primarily C. albicans and with increasing prevalence, C. glabrata, are responsible for the majority of fungal bloodstream infections that cause morbidity, especially among immune compromised patients. While the development of new antifungal agents that target the essential enzyme, dihydrofolate reductase (DHFR), in both Candida species would be ideal, previous attempts have resulted in antifolates that exhibit inconsistencies between enzyme inhibition and antifungal properties. In this article, we describe the evaluation of pairs of propargyl-linked antifolates that possess similar physicochemical properties but different shapes. All of these compounds are effective at inhibiting the fungal enzymes and the growth of C. glabrata; however, the inhibition of the growth of C. albicans is shape-dependent with extended para-linked compounds proving more effective than compact, meta-linked compounds. Using crystal structures of DHFR from C. albicans and C. glabrata bound to lead compounds, 13 new para-linked compounds designed to inhibit both species were synthesized. Eight of these compounds potently inhibit the growth of both fungal species with three compounds displaying dual MIC values less than 1 μg/mL. Analysis of the active compounds shows that shape and distribution of polar functionality is critical in achieving dual antifungal activity. PMID:24568657

  15. Effect of tyrosol on adhesion of Candida albicans and Candida glabrata to acrylic surfaces.

    PubMed

    Monteiro, Douglas Roberto; Feresin, Leonardo Perina; Arias, Laís Salomão; Barão, Valentim Adelino Ricardo; Barbosa, Debora Barros; Delbem, Alberto Carlos Botazzo

    2015-09-01

    The prevention of adhesion of Candida cells to acrylic surfaces can be regarded as an alternative to prevent denture stomatitis. The use of quorum sensing molecules, such as tyrosol, could potentially interfere with the adhesion process. Therefore, the aim of this study was to assess the effect of tyrosol on adhesion of single and mixed cultures of Candida albicans and Candida glabrata to acrylic resin surfaces. Tyrosol was diluted in each yeast inoculum (10(7) cells/ml in artificial saliva) at 25, 50, 100, and 200 mM. Then, each dilution was added to wells of 24-well plates containing the acrylic specimens, and the plates were incubated at 37°C for 2 h. After, the effect of tyrosol was determined by total biomass quantification, metabolic activity of the cells and colony-forming unit counting. Chlorhexidine gluconate (CHG) was used as a positive control. Data were analyzed using analysis of variance (ANOVA) and the Holm-Sidak post hoc test (α = 0.05). The results of total biomass quantification and metabolic activity revealed that the tyrosol promoted significant reductions (ranging from 22.32 to 86.16%) on single C. albicans and mixed cultures. Moreover, tyrosol at 200 mM and CHG significantly reduced (p < 0.05) the number of adhered cells to the acrylic surface for single and mixed cultures of both species, with reductions ranging from 1.74 to 3.64-log10. In conclusion, tyrosol has an inhibitory effect on Candida adhesion to acrylic resin, and further investigations are warranted to clarify its potential against Candida infections. PMID:26162470

  16. 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). PMID:24252829

  17. Gastrointestinal granuloma due to Candida albicans in an immunocompetent cat

    PubMed Central

    Duchaussoy, Anne-Claire; Rose, Annie; Talbot, Jessica J.; Barrs, Vanessa R.

    2015-01-01

    A 3.5 year-old cat was admitted to the University of Melbourne Veterinary Teaching Hospital for chronic vomiting. Abdominal ultrasonography revealed a focal, circumferential thickening of the wall of the duodenum extending from the pylorus aborally for 3 cm, and an enlarged gastric lymph node. Cytology of fine-needle aspirates of the intestinal mass and lymph node revealed an eosinophilic inflammatory infiltrate and numerous extracellular septate acute angle branching fungal-type hyphae. Occasional hyphae had globose terminal ends, as well as round to oval blastospores and germ tubes. Candida albicans was cultured from a surgical biopsy of the duodenal mass. No underlying host immunodeficiencies were identified. Passage of an abrasive intestinal foreign body was suspected to have caused intestinal mucosal damage resulting in focal intestinal candidiasis. The cat was treated with a short course of oral itraconazole and all clinical signs resolved. PMID:26862475

  18. Epithelial discrimination of commensal and pathogenic Candida albicans.

    PubMed

    Tang, S X; Moyes, D L; Richardson, J P; Blagojevic, M; Naglik, J R

    2016-04-01

    All mucosal surfaces are lined by epithelial cells and are colonised by opportunistic microbes. In health, these opportunistic microbes remain commensal and are tolerated by the immune system. However, when the correct environmental conditions arise, these microbes can become pathogenic and need to be controlled or cleared by the immune system to prevent disease. The mechanisms that enable epithelial cells to initiate the 'danger' signals activated specifically by pathogenic microbes are critical to mucosal defence and homeostasis but are not well understood. Deciphering these mechanisms will provide essential understanding to how mucosal tissues maintain health and activate immunity, as well as how pathogens promote disease. This review focuses on the interaction of the human fungal pathogen Candida albicans with epithelial cells and the epithelial mechanisms that enable mucosal tissues to discriminate between the commensal and pathogenic state of this medically important fungus. PMID:26843519

  19. In vitro activity of Caspofungin combined with Fluconazole on mixed Candida albicans and Candida glabrata biofilm.

    PubMed

    Pesee, Siripen; Angkananuwat, Chayanit; Tancharoensukjit, Sudarat; Muanmai, Somporn; Sirivan, Pattaraporn; Bubphawas, Manita; Tanarerkchai, Nissara

    2016-05-01

    The objective of this study was to evaluate the antifungal effect of caspofungin (CAS) combined with fluconazole (FLU) on the biofilm biomass and cultivable viability and microstructure ofCandida albicansandCandida glabratamixed biofilmin vitro.Biofilms were formed in a 96-well microtiter plate for crystal violet assay and colony forming unit (CFU) method and grown on plastic coverslip disks for scanning electron microscopy. MIC50of CAS and FLU against singleCandida spp.and mixedCandida spp.biofilms were evaluated using crystal violet assay. Additional,C. albicansandC. glabratamixed biofilms were incubated with subinhibitory CAS concentration plus FLU and their percentages ofCandidabiofilm reduction were calculated. We found that percentages of biofilm reduction were significantly decreased when CAS at 0.25MIC and FLU (0.25 or 0.5MIC) were combined (P< .05) but not different when CAS at 0.5 MIC combined with FLU at 0.25 or 0.5MIC, compared to CAS treatment alone. Structural analyses revealed that CAS/FLU combination-treated biofilms showed less hyphae and blastospores with some aberrant cells compared to control group. Although it was evident that a greater CFU ofCandida glabratawere demonstrated in every group, the total viable cells derived from CAS/FLU combination-treated biofilms at any ratio were not significantly different from positive control. Overall, CAS/FLU combinations appeared to affect the quantity and cell architecture, but number of viable cell, ofCandida albicansandCandida glabratamixed biofilm. This antifungal effect was CAS concentration dependent. PMID:26768371

  20. Miltefosine is effective against Candida albicans and Fusarium oxysporum nail biofilms in vitro.

    PubMed

    Machado Vila, Taissa Vieira; Sousa Quintanilha, Natália; Rozental, Sonia

    2015-11-01

    Onychomycosis is a fungal nail infection that represents ∼50 % of all nail disease cases worldwide. Clinical treatment with standard antifungals frequently requires long-term systemic therapy to avoid chronic disease. Onychomycosis caused by non-dermatophyte moulds, such as Fusarium spp., and yeasts, such as Candida spp., is particularly difficult to treat, possibly due to the formation of drug-resistant fungal biofilms on affected areas. Here, we show that the alkylphospholipid miltefosine, used clinically against leishmaniasis and cutaneous breast metastases, has potent activity against biofilms of Fusarium oxysporum and Candida albicans formed on human nail fragments in vitro. Miltefosine activity was compared with that of commercially available antifungals in the treatment of biofilms at two distinct developmental phases: formation and maturation (pre-formed biofilms). Drug activity towards biofilms formed on nail fragments and on microplate surfaces (microdilution assays) was evaluated using XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assays, and drug effects on fingernail biofilms were analysed by scanning electron microscopy (SEM). For F. oxysporum, miltefosine at 8 μg ml- 1 inhibited biofilm formation by 93%, whilst 256 μg ml- 1 reduced the metabolic activity of pre-formed nail biofilms by 93%. Treatment with miltefosine at 1000 μg ml- 1 inhibited biofilm formation by 89% and reduced the metabolic activity of pre-formed C. albicans biofilms by 99%. SEM analyses of biofilms formed on fingernail fragments showed a clear reduction in biofilm biomass after miltefosine treatment, in agreement with XTT results. Our results show that miltefosine has potential as a therapeutic agent against onychomycosis and should be considered for in vivo efficacy studies, especially in topical formulations for refractory disease treatment. PMID:26404553

  1. Attenuated virulence of chitin-deficient mutants of Candida albicans.

    PubMed Central

    Bulawa, C E; Miller, D W; Henry, L K; Becker, J M

    1995-01-01

    We have analyzed the role of chitin, a cell-wall polysaccharide, in the virulence of Candida albicans. Mutants with a 5-fold reduction in chitin were obtained in two ways: (i) by selecting mutants resistant to Calcofluor, a fluorescent dye that binds to chitin and inhibits growth, and (ii) by disrupting CHS3, the C. albicans homolog of CSD2/CAL1/DIT101/KT12, a Saccharomyces cerevisiae gene required for synthesis of approximately 90% of the cell-wall chitin. Chitin-deficient mutants have no obvious alterations in growth rate, sugar assimilation, chlamydospore formation, or germ-tube formation in various media. When growing vegetatively in liquid media, the mutants tend to clump and display minor changes in morphology. Staining of cells with the fluorescent dye Calcofluor indicates that CHS3 is required for synthesis of the chitin rings found on the surface of yeast cells but not formation of septa in either yeast cells or germ tubes. Despite their relatively normal growth, the mutants are significantly less virulent than the parental strain in both immunocompetent and immunosuppressed mice; at 13 days after infection, survival was 95% in immunocompetent mice that received chs3/chs3 cells and 10% in immunocompetent mice that received an equal dose of chs3/CHS3 cells. Chitin-deficient strains can colonize the organs of infected mice, suggesting that the reduced virulence of the mutants is not due to accelerated clearing. Images Fig. 1 Fig. 2 PMID:7479842

  2. Modulation of Candida albicans Biofilm by Different Carbon Sources.

    PubMed

    Pemmaraju, Suma C; Pruthi, Parul A; Prasad, R; Pruthi, Vikas

    2016-06-01

    In the present investigation, the role of carbon sources (glucose, lactate, sucrose, and arabinose) on Candida albicans biofilm development and virulence factors was studied on polystyrene microtiter plates. Besides this, structural changes in cell wall component β-glucan in presence of different carbon sources have also been highlighted. Biofilm formation was analyzed by XTT (2,3-bis[2-Methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay. Glucose-grown cells exhibited the highest metabolic activity during adhesion among all carbon sources tested (p < 0.05). However, cells exposed to sucrose exhibited highest biofilm formation and matrix polysaccharides secretion after 48 h. The results also correlated with the biofilm height and roughness measurements by atomic force microscopy. Exposure to lactate induced hyphal structures with the highest proteinase activity while arabinose-grown cells formed pseudohyphal structures possessing the highest phospholipase activity. Structural changes in β-glucan characterized by Fourier transform infrared (FTIR) spectroscopy displayed characteristic band of β-glucan at 892 cm(-1) in all carbon sources tested. The β(1→6) to β(1→3) glucan ratio calculated as per the band area of the peak was less in lactate (1.15) as compared to glucose (1.73), sucrose (1.62), and arabinose (2.85). These results signify that carbon sources influence C. albicans biofilm development and modulate virulence factors and structural organization of cell wall component β-glucan. PMID:26899861

  3. Characterization of a fucoside-binding adhesin of Candida albicans.

    PubMed Central

    Tosh, F D; Douglas, L J

    1992-01-01

    Candida albicans GDH 2346 produces extracellular polymeric material (EP) which contains a mannoprotein adhesin with a lectin-like affinity for fucose-containing glycosides. EP isolated from culture supernatants of this strain was used as starting material for purification of the adhesin. The purification protocol involved a stepwise treatment of EP with N-glycanase, papain, and dilute alkali to cleave the protein and carbohydrate portions of the mannoprotein molecule. Fucoside-binding protein fragments were then recovered by affinity adsorption with the trisaccharide determinant of the H (type 2) blood group antigen which terminates in a residue of L-fucose. The purified adhesin was devoid of carbohydrate and inhibited yeast adhesion to buccal epithelial cells 221 times more efficiently, on a protein weight basis, than did EP. Adhesion inhibition reached a maximum of 78 to 80% at an adhesin concentration of 10 micrograms ml-1. Our results indicate that this protein is the major adhesin of yeast-phase cells of C. albicans GDH 2346 but that one or more secondary adhesion mechanisms may operate. PMID:1398983

  4. Scolopendin 2 leads to cellular stress response in Candida albicans.

    PubMed

    Lee, Heejeong; Hwang, Jae-Sam; Lee, Dong Gun

    2016-07-01

    Centipedes, a kind of arthropod, have been reported to produce antimicrobial peptides as part of an innate immune response. Scolopendin 2 (AGLQFPVGRIGRLLRK) is a novel antimicrobial peptide derived from the body of the centipede Scolopendra subspinipes mutilans by using RNA sequencing. To investigate the intracellular responses induced by scolopendin 2, reactive oxygen species (ROS) and glutathione accumulation and lipid peroxidation were monitored over sublethal and lethal doses. Intracellular ROS and antioxidant molecule levels were elevated and lipids were peroxidized at sublethal concentrations. Moreover, the Ca(2+) released from the endoplasmic reticulum accumulated in the cytosol and mitochondria. These stress responses were considered to be associated with yeast apoptosis. Candida albicans cells exposed to scolopendin 2 were identified using diagnostic markers of apoptotic response. Various responses such as phosphatidylserine externalization, chromatin condensation, and nuclear fragmentation were exhibited. Scolopendin 2 disrupted the mitochondrial membrane potential and activated metacaspase, which was mediated by cytochrome c release. In conclusion, treatment of C. albicans with scolopendin 2 induced the apoptotic response at sublethal doses, which in turn led to mitochondrial dysfunction, metacaspase activation, and cell death. The cationic antimicrobial peptide scolopendin 2 from the centipede is a potential antifungal peptide, triggering the apoptotic response. PMID:27207682

  5. A patient with allergic bronchopulmonary mycosis caused by Aspergillus fumigatus and Candida albicans.

    PubMed

    Wardhana; Datau, E A

    2012-10-01

    Allergic Bronchopulmonary Mycosis (ABPM) is an exagregated immunologic response to fungal colonization in the lower airways. It may cause by many kinds of fungal, but Aspergillus fumigatus is the most common cause of ABPM, although other Aspergillus and other fungal organisms, like Candida albicans, have been implicated. Aspergllus fumigatus and Candida albicans may be found as outdoor and indoor fungi, and cause the sensitization, elicitation of the disease pathology, and its clinical manifestations. Several diagnostic procedurs may be impicated to support the diagnosis of ABPM caused by Aspergillus fumigatus and Candida albicans. A case of allergic bronchopulmonary mycosis caused by Aspergillus fumigatus and Candida albicans in a 48 year old man was discussed. The patient was treated with antifungal, corticosteroids, and antibiotic for the secondary bacterial infection. The patient's condition is improved without any significant side effects. PMID:23314973

  6. Functional diversity of complex I subunits in Candida albicans mitochondria.

    PubMed

    Li, Dongmei; She, Xiaodong; Calderone, Richard

    2016-02-01

    Our interest in the mitochondria of Candida albicans has progressed to the identification of several proteins that are critical to complex I (CI) activity. We speculated that there should be major functional differences at the protein level between mammalian and fungal mitochondria CI. In our pursuit of this idea, we were helped by published data of CI subunit proteins from a broad diversity of species that included two subunit proteins that are not found in mammals. These subunit proteins have been designated as Nuo1p and Nuo2p (NADH-ubiquinone oxidoreductases). Since functional assignments of both C. albicans proteins were unknown, other than having a putative NADH-oxidoreductase activity, we constructed knock-out strains that could be compared to parental cells. The relevance of our research relates to the critical roles of both proteins in cell biology and pathogenesis and their absence in mammals. These features suggest they may be exploited in antifungal drug discovery. Initially, we characterized Goa1p that apparently regulates CI activity but is not a CI subunit protein. We have used the goa1∆ for comparisons to Nuo1p and Nuo2p. We have demonstrated the critical role of these proteins in maintaining CI activities, virulence, and prolonging life span. More recently, transcriptional profiling of the three mutants and an ndh51∆ (protein is a highly conserved CI subunit) has revealed that there are overlapping yet also different functional assignments that suggest subunit specificity. The differences and similarities of each are described below along with our hypotheses to explain these data. Our conclusion and perspective is that the C. albicans CI subunit proteins are highly conserved except for two that define non-mammalian functions. PMID:26373419

  7. Early detection of Candida albicans biofilms at porous electrodes.

    PubMed

    Congdon, Robert B; Feldberg, Alexander S; Ben-Yakar, Natalie; McGee, Dennis; Ober, Christopher; Sammakia, Bahgat; Sadik, Omowunmi A

    2013-02-15

    We describe the development of an electrochemical sensor for early detection of biofilm using Candida albicans. The electrochemical sensor used the ability of biofilms to accept electrons from redox mediators relative to the number of metabolically active cells present. Cyclic voltammetry and differential pulse voltammetry techniques were used to monitor the redox reaction of K(3)Fe(CN)(6) at porous reticulated vitreous carbon (RVC) (238.7 cm(2)) working electrodes versus Ag/AgCl reference. A shift in the peak potential occurred after 12 h of film growth, which is attributed to the presence of C. albicans. Moreover, the intensity of the ferricyanide reduction peak first increased as C. albicans deposited onto the porous electrodes at various growth times. The peak current subsequently decreased at extended periods of growth of 48 h. The reduction in peak current was attributed to the biofilm reaching its maximum growth thickness, which correlated with the maximum number of metabolically active cells. The observed diffusion coefficients for the bare RVC and biofilm-coated electrodes were 2.2 × 10(-3) and 7.0 × 10(-6) cm(2)/s, respectively. The increase in diffusivity from the bare electrode to the biofilm-coated electrode indicated some enhancement of electron transfer mediated by the biofilm to the porous electrode. Verification of the growth of biofilm was achieved using scanning electron microcopy and laser scanning confocal imaging microscopy. Validation with conventional plating techniques confirmed that the correlation (R(2) = 0.9392) could be achieved between the electrochemical sensors data and colony-forming units. PMID:23107627

  8. Vaginal lactobacilli as potential probiotics against Candida SPP.

    PubMed

    Gil, Natalia F; Martinez, Rafael C R; Gomes, Bruna C; Nomizo, Auro; De Martinis, Elaine C P

    2010-01-01

    Urogenital infections affect millions of people every year worldwide. The treatment of these diseases usually requires the use of antimicrobial agents, and more recently, the use of probiotic lactic acid bacteria (LAB) cultures for the management of vaginal infections has been extensively studied. In this work, 11 vaginal lactobacilli isolates, previously obtained from healthy patients, were studied to screen microorganisms with probiotic properties against Candida spp. The LAB were tested for their ability of auto-aggregation, co-aggregation with C. albicans, C. glabrata, C. krusei, and C. tropicalis, adhesion to Caco-2 epithelial cells and production of lactic acid and hydrogen peroxide (H2O2). All lactobacilli isolates tested were able to auto-aggregate (ranging from 25.3% to 75.4% assessed at 4 hours of incubation) and to co-aggregate with the four Candida species into different degrees; among them L. crispatus showed the highest scores of co-aggregation. The highest amount of lactic acid was produced by L. salivarius (13.9 g/l), followed by L. johnsonii (6.5 g/l), L. acidophilus (5.5 g/l), and L. jensenii (5.4 g/l). All isolates produced H2O2, but the highest levels (3 - 10 mg/l) were observed for L. acidophilus, L. crispatus, L. gasseri, L. johnsonii, and L. vaginalis. Only L. agilis, L. jensenii, L. johnsonii and L. ruminus were able to adhere to epithelial Caco-2 cells. Among the isolates evaluated, L agilis, L. jensenii, L. johnsonii, and L. ruminus exhibited simultaneously several desirable properties as potential probiotic strains justifying future studies to evaluate their technological properties in different pharmaceutical preparations for human use. PMID:24031455

  9. Vaginal lactobacilli as potential probiotics against Candida SPP.

    PubMed Central

    Gil1, Natalia F.; Martinez, Rafael C.R.; Gomes, Bruna C.; Nomizo, Auro; De Martinis, Elaine C. P.

    2010-01-01

    Urogenital infections affect millions of people every year worldwide. The treatment of these diseases usually requires the use of antimicrobial agents, and more recently, the use of probiotic lactic acid bacteria (LAB) cultures for the management of vaginal infections has been extensively studied. In this work, 11 vaginal lactobacilli isolates, previously obtained from healthy patients, were studied to screen microorganisms with probiotic properties against Candida spp. The LAB were tested for their ability of auto-aggregation, co-aggregation with C. albicans, C. glabrata, C. krusei, and C. tropicalis, adhesion to Caco-2 epithelial cells and production of lactic acid and hydrogen peroxide (H2O2). All lactobacilli isolates tested were able to auto-aggregate (ranging from 25.3% to 75.4% assessed at 4 hours of incubation) and to co-aggregate with the four Candida species into different degrees; among them L. crispatus showed the highest scores of co-aggregation. The highest amount of lactic acid was produced by L. salivarius (13.9 g/l), followed by L. johnsonii (6.5 g/l), L. acidophilus (5.5 g/l), and L. jensenii (5.4 g/l). All isolates produced H2O2, but the highest levels (3 – 10 mg/l) were observed for L. acidophilus, L. crispatus, L. gasseri, L. johnsonii, and L. vaginalis. Only L. agilis, L. jensenii, L. johnsonii and L. ruminus were able to adhere to epithelial Caco-2 cells. Among the isolates evaluated, L agilis, L. jensenii, L. johnsonii, and L. ruminus exhibited simultaneously several desirable properties as potential probiotic strains justifying future studies to evaluate their technological properties in different pharmaceutical preparations for human use. PMID:24031455

  10. Investigation of minor species Candida africana, Candida stellatoidea and Candida dubliniensis in the Candida albicans complex among Yaoundé (Cameroon) HIV-infected patients.

    PubMed

    Ngouana, Thierry K; Krasteva, Donika; Drakulovski, Pascal; Toghueo, Rufin K; Kouanfack, Charles; Ambe, Akaba; Reynes, Jacques; Delaporte, Eric; Boyom, Fabrice F; Mallié, Michèle; Bertout, Sébastien

    2015-01-01

    Minor species of the Candida albicans complex may cause overestimation of the epidemiology of C. albicans, and misidentifications could mask their implication in human pathology. Authors determined the occurrence of minor species of the C. albicans complex (C. africana, C. dubliniensis and C. stellatoidea) among Yaoundé HIV-infected patients, Cameroon. Stool, vaginal discharge, urine and oropharyngeal samples were analysed by mycological diagnosis. Isolates were identified by conventional methods and mass spectrometry (MS; carried out by the matrix-assisted laser desorption-ionisation time-of-flight MS protocol). Candida albicans isolates were thereafter submitted to the PCR amplification of the Hwp1 gene. The susceptibility of isolates to antifungal drugs was tested using the Clinical and Laboratory Standards Institute M27-A3 protocol. From 115 C. albicans obtained isolates, neither C. dubliniensis nor C. stellatoidea was observed; two strains of C. africana (422PV and 448PV) were identified by PCR electrophoretic profiles at 700 bp. These two C. africana strains were vaginal isolates. The isolate 448PV was resistant to ketoconazole at the minimal inhibitory concentration of 2 μg ml(-1), and showed reduced susceptibility to amphotericin B at 1 μg ml(-1). This first report on C. africana occurrence in Cameroon brings clues for the understanding of the global epidemiology of this yeast as well as that of minor species of the C. albicans complex. PMID:25289589

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  12. Enhanced production of farnesol by Candida albicans treated with four azoles.

    PubMed

    Hornby, Jacob M; Nickerson, Kenneth W

    2004-06-01

    The dimorphic fungus Candida albicans excretes farnesol, which is produced enzymatically from the sterol biosynthetic intermediate farnesyl pyrophosphate. Inhibition of C. albicans by four azole antifungals, fluconazole, ketoconazole, miconazole, and clotrimazole, caused elevated farnesol production (10- to 45-fold). Furthermore, farnesol production occurs in both laboratory strains and clinical isolates (J. M. Hornby et al., Appl. Environ. Microbiol. 67:2982-2992, 2001) of C. albicans. PMID:15155241

  13. National surveillance of nosocomial blood stream infection due to species of Candida other than Candida albicans: frequency of occurrence and antifungal susceptibility in the SCOPE Program. SCOPE Participant Group. Surveillance and Control of Pathogens of Epidemiologic.

    PubMed

    Pfaller, M A; Jones, R N; Messer, S A; Edmond, M B; Wenzel, R P

    1998-02-01

    A national surveillance program of nosocomial blood stream infections (BSI) in the USA between April 1995 and June 1996 revealed that Candida was the fourth leading cause of nosocomial BSI, accounting for 8% of all infections. Forty-eight percent of 379 episodes of candidemia were due to species other than Candida albicans. The rank order of non-C. albicans species was C. glabrata (20%) > C. tropicalis (11%) > C. parapsilosis (8%) > C. krusei (5%) > other Candida spp. (4%). The species distribution varied according to geographic region, with non-C. albicans species predominating in the Northeast (54%) and Southeast (53%) regions, and C. albicans predominating in the Northwest (60%) and Southwest (70%) regions. In vitro susceptibility studies demonstrated that 95% of non-C. albicans isolates were susceptible to 5-fluorocytosine, and 84% and 75% were susceptible to fluconazole and itraconazole, respectively. Geographic variation in susceptibility to itraconazole, but not other agents, was observed. Isolates from the Northwest and Southeast regions were more frequently resistant to itraconazole (29-30%) than those from the Northeast and Southwest regions (17-18%). Molecular epidemiologic studies revealed possible nosocomial transmission (five medical centers). Continued surveillance for the presence of non-C. albicans species among hospitalized patients is recommended. PMID:9554180

  14. Candida albicans strain types from the genitalia of patients with and without Candida infection.

    PubMed

    Odds, F C; Abbott, A B; Reed, T A; Willmott, F E

    1983-04-01

    The strain phenotypes of 266 C. albicans isolates from patients attending a genitourinary clinic were determined on the basis of 9 biochemical tests. Analysis of the strain patterns of isolates from the genitalia showed that there were no statistically significant differences between types associated with clinically overt Candida infection and types isolated in the absence of symptoms of candidosis. This finding accords with the traditional view of C. albicans as an opportunistic pathogen, rather than a species containing some strains of high virulence. In cases where isolations were made from the same patient at different times, or from different anatomical sites in the same patient, it was found that usually, but not always, a patient carried the same phenotype at different sites and different times. Similarly, the same strain type was isolated from the genitalis of both partners in a majority of instances where strains were isolated from consorts; however, this was not the case for a substantial minority of couples, particularly in those where high promiscuity appeared to promote considerable mixture and interchange of the C. albicans genital microflora. PMID:6350074

  15. Performance comparison of phenotypic and molecular methods for detection and differentiation of Candida albicans and Candida dubliniensis

    PubMed Central

    2012-01-01

    Background Candida albicans is the most pathogenic Candida species but shares many phenotypic features with Candida dubliniensis and may, therefore, be misidentified in clinical microbiology laboratories. Candidemia cases due to C. dubliniensis are increasingly being reported in recent years. Accurate identification is warranted since mortality rates are highest for C. albicans infections, however, C. dubliniensis has the propensity to develop resistance against azoles more easily. We developed a duplex PCR assay for rapid detection and differentiation of C. albicans from C. dubliniensis for resource-poor settings equipped with basic PCR technology and compared its performance with three phenotypic methods. Methods Duplex PCR was performed on 122 germ tube positive and 12 germ tube negative isolates of Candida species previously identified by assimilation profiles on Vitek 2 ID-YST system. Typical morphologic characteristics on simplified sunflower seed agar (SSA), and reaction with a commercial (Bichro-Dubli) latex agglutination test were also performed. The assay was further applied on 239 clinical yeast and yeast-like fungi and results were confirmed by DNA sequencing of internal transcribed spacer (ITS) region of rDNA. Results The results of duplex PCR assay for 122 germ tube positive and 12 germ tube negative isolates of Candida species were comparable to their identification by Vitek 2 ID-YST system, colony characteristics on SSA and latex agglutination test. Application of duplex PCR also correctly identified all 148 C. albicans and 50 C. dubliniensis strains among 239 yeast-like fungi. Conclusions The data show that both, duplex PCR and Bichro-Dubli are reliable tests for rapid (within few hours) identification of clinical yeast isolates as C. dubliniensis or C. albicans. However, duplex PCR may be applied directly on clinical yeast isolates for their identification as C. dubliniensis or C. albicans as it does not require prior testing for germ tube

  16. Live Candida albicans Suppresses Production of Reactive Oxygen Species in Phagocytes▿ †

    PubMed Central

    Wellington, Melanie; Dolan, Kristy; Krysan, Damian J.

    2009-01-01

    Production of reactive oxygen species (ROS) is an important aspect of phagocyte-mediated host responses. Since phagocytes play a crucial role in the host response to Candida albicans, we examined the ability of Candida to modulate phagocyte ROS production. ROS production was measured in the murine macrophage cell line J774 and in primary phagocytes using luminol-enhanced chemiluminescence. J774 cells, murine polymorphonuclear leukocytes (PMN), human monocytes, and human PMN treated with live C. albicans produced significantly less ROS than phagocytes treated with heat-killed C. albicans. Live C. albicans also suppressed ROS production in murine bone marrow-derived macrophages from C57BL/6 mice, but not from BALB/c mice. Live C. albicans also suppressed ROS in response to external stimuli. C. albicans and Candida glabrata suppressed ROS production by phagocytes, whereas Saccharomyces cerevisiae stimulated ROS production. The cell wall is the initial point of contact between Candida and phagocytes, but isolated cell walls from both heat-killed and live C. albicans stimulated ROS production. Heat-killed C. albicans has increased surface exposure of 1,3-β-glucan, a cell wall component that can stimulate phagocytes. To determine whether surface 1,3-β-glucan exposure accounted for the difference in ROS production, live C. albicans cells were treated with a sublethal dose of caspofungin to increase surface 1,3-β-glucan exposure. Caspofungin-treated C. albicans was fully able to suppress ROS production, indicating that suppression of ROS overrides stimulatory signals from 1,3-β-glucan. These studies indicate that live C. albicans actively suppresses ROS production in phagocytes in vitro, which may represent an important immune evasion mechanism. PMID:18981256

  17. The Fungus Candida albicans Tolerates Ambiguity at Multiple Codons

    PubMed Central

    Simões, João; Bezerra, Ana R.; Moura, Gabriela R.; Araújo, Hugo; Gut, Ivo; Bayes, Mónica; Santos, Manuel A. S.

    2016-01-01

    The ascomycete Candida albicans is a normal resident of the gastrointestinal tract of humans and other warm-blooded animals. It occurs in a broad range of body sites and has high capacity to survive and proliferate in adverse environments with drastic changes in oxygen, carbon dioxide, pH, osmolarity, nutrients, and temperature. Its biology is unique due to flexible reassignment of the leucine CUG codon to serine and synthesis of statistical proteins. Under standard growth conditions, CUG sites incorporate leucine (3% of the times) and serine (97% of the times) on a proteome wide scale, but leucine incorporation fluctuates in response to environmental stressors and can be artificially increased up to 98%. In order to determine whether such flexibility also exists at other codons, we have constructed several serine tRNAs that decode various non-cognate codons. Expression of these tRNAs had minor effects on fitness, but growth of the mistranslating strains at different temperatures, in medium with different pH and nutrients composition was often enhanced relatively to the wild type (WT) strain, supporting our previous data on adaptive roles of CUG ambiguity in variable growth conditions. Parallel evolution of the recombinant strains (100 generations) followed by full genome resequencing identified various strain specific single nucleotide polymorphisms (SNP) and one SNP in the deneddylase (JAB1) gene in all strains. Since JAB1 is a subunit of the COP9 signalosome complex, which interacts with cullin (Cdc53p) to mediate degradation of a variety of cellular proteins, our data suggest that neddylation plays a key role in tolerance and adaptation to codon ambiguity in C. albicans. PMID:27065968

  18. The Fungus Candida albicans Tolerates Ambiguity at Multiple Codons.

    PubMed

    Simões, João; Bezerra, Ana R; Moura, Gabriela R; Araújo, Hugo; Gut, Ivo; Bayes, Mónica; Santos, Manuel A S

    2016-01-01

    The ascomycete Candida albicans is a normal resident of the gastrointestinal tract of humans and other warm-blooded animals. It occurs in a broad range of body sites and has high capacity to survive and proliferate in adverse environments with drastic changes in oxygen, carbon dioxide, pH, osmolarity, nutrients, and temperature. Its biology is unique due to flexible reassignment of the leucine CUG codon to serine and synthesis of statistical proteins. Under standard growth conditions, CUG sites incorporate leucine (3% of the times) and serine (97% of the times) on a proteome wide scale, but leucine incorporation fluctuates in response to environmental stressors and can be artificially increased up to 98%. In order to determine whether such flexibility also exists at other codons, we have constructed several serine tRNAs that decode various non-cognate codons. Expression of these tRNAs had minor effects on fitness, but growth of the mistranslating strains at different temperatures, in medium with different pH and nutrients composition was often enhanced relatively to the wild type (WT) strain, supporting our previous data on adaptive roles of CUG ambiguity in variable growth conditions. Parallel evolution of the recombinant strains (100 generations) followed by full genome resequencing identified various strain specific single nucleotide polymorphisms (SNP) and one SNP in the deneddylase (JAB1) gene in all strains. Since JAB1 is a subunit of the COP9 signalosome complex, which interacts with cullin (Cdc53p) to mediate degradation of a variety of cellular proteins, our data suggest that neddylation plays a key role in tolerance and adaptation to codon ambiguity in C. albicans. PMID:27065968

  19. Function and Regulation of Cph2 in Candida albicans

    PubMed Central

    Lane, Shelley; Di Lena, Pietro; Tormanen, Kati; Baldi, Pierre

    2015-01-01

    Candida albicans is associated with humans as both a harmless commensal organism and a pathogen. Cph2 is a transcription factor whose DNA binding domain is similar to that of mammalian sterol response element binding proteins (SREBPs). SREBPs are master regulators of cellular cholesterol levels and are highly conserved from fungi to mammals. However, ergosterol biosynthesis is regulated by the zinc finger transcription factor Upc2 in C. albicans and several other yeasts. Cph2 is not necessary for ergosterol biosynthesis but is important for colonization in the murine gastrointestinal (GI) tract. Here we demonstrate that Cph2 is a membrane-associated transcription factor that is processed to release the N-terminal DNA binding domain like SREBPs, but its cleavage is not regulated by cellular levels of ergosterol or oxygen. Chromatin immunoprecipitation sequencing (ChIP-seq) shows that Cph2 binds to the promoters of HMS1 and other components of the regulatory circuit for GI tract colonization. In addition, 50% of Cph2 targets are also bound by Hms1 and other factors of the regulatory circuit. Several common targets function at the head of the glycolysis pathway. Thus, Cph2 is an integral part of the regulatory circuit for GI colonization that regulates glycolytic flux. Transcriptome sequencing (RNA-seq) shows a significant overlap in genes differentially regulated by Cph2 and hypoxia, and Cph2 is important for optimal expression of some hypoxia-responsive genes in glycolysis and the citric acid cycle. We suggest that Cph2 and Upc2 regulate hypoxia-responsive expression in different pathways, consistent with a synthetic lethal defect of the cph2 upc2 double mutant in hypoxia. PMID:26342020

  20. Humoral Immunity Links Candida albicans Infection and Celiac Disease

    PubMed Central

    Fradin, Chantal; Salleron, Julia; Damiens, Sébastien; Moragues, Maria Dolores; Souplet, Vianney; Jouault, Thierry; Robert, Raymond; Dubucquoi, Sylvain; Sendid, Boualem; Colombel, Jean Fréderic; Poulain, Daniel

    2015-01-01

    Objective The protein Hwp1, expressed on the pathogenic phase of Candida albicans, presents sequence analogy with the gluten protein gliadin and is also a substrate for transglutaminase. This had led to the suggestion that C. albicans infection (CI) may be a triggering factor for Celiac disease (CeD) onset. We investigated cross-immune reactivity between CeD and CI. Methods Serum IgG levels against recombinant Hwp1 and serological markers of CeD were measured in 87 CeD patients, 41 CI patients, and 98 healthy controls (HC). IgA and IgG were also measured in 20 individuals from each of these groups using microchips sensitized with 38 peptides designed from the N-terminal of Hwp1. Results CI and CeD patients had higher levels of anti-Hwp1 (p=0.0005 and p=0.004) and anti-gliadin (p=0.002 and p=0.0009) antibodies than HC but there was no significant difference between CeD and CI patients. CeD and CI patients had higher levels of anti-transglutaminase IgA than HC (p=0.0001 and p=0.0039). During CI, the increase in anti-Hwp1 paralleled the increase in anti-gliadin antibodies. Microchip analysis showed that CeD patients were more reactive against some Hwp1 peptides than CI patients, and that some deamidated peptides were more reactive than their native analogs. Binding of IgG from CeD patients to Hwp1 peptides was inhibited by γIII gliadin peptides. Conclusions Humoral cross-reactivity between Hwp1 and gliadin was observed during CeD and CI. Increased reactivity to Hwp1 deamidated peptide suggests that transglutaminase is involved in this interplay. These results support the hypothesis that CI may trigger CeD onset in genetically-susceptible individuals. PMID:25793717

  1. Functional characterization of Candida albicans Hos2 histone deacetylase

    PubMed Central

    Karthikeyan, G; Paul-Satyaseela, Maneesh; Dhatchana Moorthy, Nachiappan; Gopalaswamy, Radha; Narayanan, Shridhar

    2014-01-01

    Candida albicans is a mucosal commensal organism capable of causing superficial (oral and vaginal thrush) infections in immune normal hosts, but is a major pathogen causing systemic and mucosal infections in immunocompromised individuals. Azoles have been very effective anti-fungal agents and the mainstay in treating opportunistic mold and yeast infections. Azole resistant strains have emerged compromising the utility of this class of drugs. It has been shown that azole resistance can be reversed by the co-administration of a histone deacetylase (HDAC) inhibitor, suggesting that resistance is mediated by epigenetic mechanisms possibly involving Hos2, a fungal deacetylase. We report here the cloning and functional characterization of  HOS2 (High Osmolarity  Sensitive) , a gene coding for fungal histone deacetylase from  C. albicans. Inhibition studies showed that Hos2 is susceptible to pan inhibitors such as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), but is not inhibited by class I inhibitors such as MS-275. This  in  vitro enzymatic assay, which is amenable to high throughput could be used for screening potent fungal Hos2 inhibitors that could be a potential anti-fungal adjuvant. Purified Hos2 protein consistently deacetylated tubulins, rather than histones from TSA-treated cells. Hos2 has been reported to be a putative NAD+ dependent histone deacetylase, a feature of sirtuins. We assayed for sirtuin activation with resveratrol and purified Hos2 protein and did not find any sirtuin activity. PMID:25110576

  2. Function and Regulation of Cph2 in Candida albicans.

    PubMed

    Lane, Shelley; Di Lena, Pietro; Tormanen, Kati; Baldi, Pierre; Liu, Haoping

    2015-11-01

    Candida albicans is associated with humans as both a harmless commensal organism and a pathogen. Cph2 is a transcription factor whose DNA binding domain is similar to that of mammalian sterol response element binding proteins (SREBPs). SREBPs are master regulators of cellular cholesterol levels and are highly conserved from fungi to mammals. However, ergosterol biosynthesis is regulated by the zinc finger transcription factor Upc2 in C. albicans and several other yeasts. Cph2 is not necessary for ergosterol biosynthesis but is important for colonization in the murine gastrointestinal (GI) tract. Here we demonstrate that Cph2 is a membrane-associated transcription factor that is processed to release the N-terminal DNA binding domain like SREBPs, but its cleavage is not regulated by cellular levels of ergosterol or oxygen. Chromatin immunoprecipitation sequencing (ChIP-seq) shows that Cph2 binds to the promoters of HMS1 and other components of the regulatory circuit for GI tract colonization. In addition, 50% of Cph2 targets are also bound by Hms1 and other factors of the regulatory circuit. Several common targets function at the head of the glycolysis pathway. Thus, Cph2 is an integral part of the regulatory circuit for GI colonization that regulates glycolytic flux. Transcriptome sequencing (RNA-seq) shows a significant overlap in genes differentially regulated by Cph2 and hypoxia, and Cph2 is important for optimal expression of some hypoxia-responsive genes in glycolysis and the citric acid cycle. We suggest that Cph2 and Upc2 regulate hypoxia-responsive expression in different pathways, consistent with a synthetic lethal defect of the cph2 upc2 double mutant in hypoxia. PMID:26342020

  3. Morphological and physiological changes induced by contact-dependent interaction between Candida albicans and Fusobacterium nucleatum.

    PubMed

    Bor, Batbileg; Cen, Lujia; Agnello, Melissa; Shi, Wenyuan; He, Xuesong

    2016-01-01

    Candida albicans and Fusobacterium nucleatum are well-studied oral commensal microbes with pathogenic potential that are involved in various oral polymicrobial infectious diseases. Recently, we demonstrated that F. nucleatum ATCC 23726 coaggregates with C. albicans SN152, a process mainly mediated by fusobacterial membrane protein RadD and Candida cell wall protein Flo9. The aim of this study was to investigate the potential biological impact of this inter-kingdom interaction. We found that F. nucleatum ATCC 23726 inhibits growth and hyphal morphogenesis of C. albicans SN152 in a contact-dependent manner. Further analysis revealed that the inhibition of Candida hyphal morphogenesis is mediated via RadD and Flo9 protein pair. Using a murine macrophage cell line, we showed that the F. nucleatum-induced inhibition of Candida hyphal morphogenesis promotes C. albicans survival and negatively impacts the macrophage-killing capability of C. albicans. Furthermore, the yeast form of C. albicans repressed F. nucleatum-induced MCP-1 and TNFα production in macrophages. Our study suggests that the interaction between C. albicans and F. nucleatum leads to a mutual attenuation of virulence, which may function to promote a long-term commensal lifestyle within the oral cavity. This finding has significant implications for our understanding of inter-kingdom interaction and may impact clinical treatment strategies. PMID:27295972

  4. Morphological and physiological changes induced by contact-dependent interaction between Candida albicans and Fusobacterium nucleatum

    PubMed Central

    Bor, Batbileg; Cen, Lujia; Agnello, Melissa; Shi, Wenyuan; He, Xuesong

    2016-01-01

    Candida albicans and Fusobacterium nucleatum are well-studied oral commensal microbes with pathogenic potential that are involved in various oral polymicrobial infectious diseases. Recently, we demonstrated that F. nucleatum ATCC 23726 coaggregates with C. albicans SN152, a process mainly mediated by fusobacterial membrane protein RadD and Candida cell wall protein Flo9. The aim of this study was to investigate the potential biological impact of this inter-kingdom interaction. We found that F. nucleatum ATCC 23726 inhibits growth and hyphal morphogenesis of C. albicans SN152 in a contact-dependent manner. Further analysis revealed that the inhibition of Candida hyphal morphogenesis is mediated via RadD and Flo9 protein pair. Using a murine macrophage cell line, we showed that the F. nucleatum-induced inhibition of Candida hyphal morphogenesis promotes C. albicans survival and negatively impacts the macrophage-killing capability of C. albicans. Furthermore, the yeast form of C. albicans repressed F. nucleatum-induced MCP-1 and TNFα production in macrophages. Our study suggests that the interaction between C. albicans and F. nucleatum leads to a mutual attenuation of virulence, which may function to promote a long-term commensal lifestyle within the oral cavity. This finding has significant implications for our understanding of inter-kingdom interaction and may impact clinical treatment strategies. PMID:27295972

  5. Effect of Low-Level Laser therapy on the fungal proliferation of Candida albicans

    NASA Astrophysics Data System (ADS)

    Carneiro, Vanda S. M.; Araújo, Natália C.; Menezes, Rebeca F. d.; Moreno, Lara M.; Santos-Neto, Alexandrino d. P.; Gerbi, Marleny Elizabeth M.

    2016-03-01

    Candida albicans plays an important role in triggering infections in HIV+ patients. The indiscriminate use of antifungals has led to resistance to Candida albicans, which requires new treatment alternatives for oral candidiasis. Low-level laser therapy promotes a considerable improvement in the healing of wounds and in curing illnesses caused by microorganisms. The aim of the present study was to assess the effect of laser radiation on the cell proliferation of Candida albicans in immunosuppressed patients. Six Candida albicans strains that had been isolated from immunosuppressed patients were divided into a control group and experimental groups, which received eight sessions of laser therapy (InGaAlP, λ685nm, P = 30mW, CW, Φ~6 mm and GaAlAs, λ830nm, P = 40mW, CW, Φ~6 mm) using dosimetries of 6J/cm2, 8J/cm2, 10J/cm2 and 12J/cm2 for each wavelength and power. The results were not statistically significant (Kruskal Wallis, p > 0.05), although the proliferation of Candida albicans was lower in some of the experimental groups. The dosimetry of 6J/cm2 (GaAlAs, λ830nm, P = 40mW) provided lower mean scores than the other groups for the growth of Candida. Further studies are required to confirm whetehr laser therapy is a viable option in the treatment of fungal infections.

  6. Activity of Hoechst 33258 against Pneumocystis carinii f. sp. muris, Candida albicans, and Candida dubliniensis

    PubMed Central

    Disney, Matthew D.; Stephenson, Ruth; Wright, Terry W.; Haidaris, Constantine G.; Turner, Douglas H.; Gigliotti, Francis

    2005-01-01

    Hoechst 33258 is a compound that binds nucleic acids. We report that Hoechst 33258 exhibits antimicrobial activity against Pneumocystis carinii f. sp. muris in a mouse model for P. carinii pneumonia and against Candida albicans and Candida dubliniensis in vitro. Relative to saline treatment, a 14-day, daily treatment of mice with 37.5 mg of Hoechst 33258/kg of body weight after inoculation with P. carinii reduced by about 100-fold the number of P. carinii organisms detected by either PCR or by microscopy after silver staining. For comparison, treatment based on a dose of 15 to 20 mg of the trimethoprim component in trimethoprim-sulfamethoxazole/kg reduced the number of P. carinii by about fourfold. In vitro inhibition of P. carinii group I intron splicing was observed with a 50% inhibitory concentration (IC50)of 30 μM in 2 or 4 mM Mg2+, suggesting RNA as a possible target. However, Hoechst 33258 inhibits growth of Candida strains with and without group I introns. IC50s ranged from 1 to 9 μM for strains with group I introns and were 12 and 32 μM for two strains without group I introns. These studies demonstrate that compounds that bind fungal nucleic acids have the potential to be developed as new therapeutics for Pneumocystis and possibly other fungi, especially if they could be directed to structures that are not present in mammalian cells, such as self-splicing introns. PMID:15793106

  7. Characterization of recombinant homocitrate synthase from Candida albicans.

    PubMed

    Gabriel, Iwona; Milewski, Sławomir

    2016-09-01

    LYS21 and LYS22 genes from Candida albicans encoding isoforms of homocitrate synthase (HCS), an enzyme catalyzing the first committed step in the l-lysine biosynthetic pathway, were cloned and expressed as N-oligoHistagged fusion proteins in Escherichia coli. The purified gene products revealed HCS activity, i.e. catalyzed the condensation of α-ketoglutarate with acetyl-coenzyme A to yield homocitrate. The recombinant enzymes were purified to homogeneity and characterized for their physical properties and substrate specificities. As determined by size-exclusion chromatography (SEC) and native page electrophoresis, both isoenzymes adopt multiple quaternary structures, with the homotetrameric one being the most abundant. The KM (acetyl-CoA)=0.8±0.15mM and KM (α-ketoglutarate)=0.113±0.02mM for His6CaLys21p and KM (acetyl-CoA)=0.48±0.09mM and KM (α-ketoglutarate)=0.152±0.03mM values for His6CaLys22p were determined. Both enzyme versions were inhibited by l-Lys, i.e. the end product of the α-aminoadipate pathway but Lys22p was more sensitive than Lys21p, with Ki (L-Lys)=128±8μM for His6CaLys21p and Ki (L-Lys)=4.37±0.68μM for His6CaLys22p. The isoforms of C. albicans HCS exhibited differential sensitivity to several l-Lys analogues. Most notably, dl-α-difluoromethyllysine strongly inhibited His6CaLys22p (IC50 32±3μM) but was not inhibitory at all towards His6CaLys21p. Differential sensitivity of recombinant C. albicans Δlys21/LYS22, LYS21/Δlys22 and Δlys21/Δlys22 mutant strains to lysine analog, 2-aminoethyl-l-cysteine and biochemical properties of homocitrate synthase isoforms suggest different roles of two HCS isoenzymes in α-aminoadipate pathway. PMID:26363118

  8. Oral administration of the broad-spectrum antibiofilm compound toremifene inhibits Candida albicans and Staphylococcus aureus biofilm formation in vivo.

    PubMed

    De Cremer, Kaat; Delattin, Nicolas; De Brucker, Katrijn; Peeters, Annelies; Kucharíková, Soña; Gerits, Evelien; Verstraeten, Natalie; Michiels, Jan; Van Dijck, Patrick; Cammue, Bruno P A; Thevissen, Karin

    2014-12-01

    We here report on the in vitro activity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, including Candida albicans, Candida glabrata, Candida dubliniensis, Candida krusei, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We validated the in vivo efficacy of orally administered toremifene against C. albicans and S. aureus biofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound. PMID:25288093

  9. Upc2p-associated differential protein expression in Candida albicans.

    PubMed

    Hoehamer, Christopher F; Cummings, Edwin D; Hilliard, George M; Morschhäuser, Joachim; David Rogers, Phillip

    2009-10-01

    The gain-of-function mutation G648D in UPC2 causes ERG11 up-regulation and increased fluconazole resistance in Candida albicans. In this study, we performed 2-DE and PMF to identify proteomic alterations in an ERG11-overexpressing fluconazole-resistant C. albicans clinical isolate compared with its fluconazole-susceptible parent strain. We identified 23 differentially expressed proteins, and among them, seven became differentially expressed in a C. albicans wild-type strain after the introduction of a UPC2 allele carrying this mutation. These Upc2p-regulated proteins may contribute to fluconazole resistance in C. albicans. PMID:19750515

  10. Regulation of copper toxicity by Candida albicans GPA2.

    PubMed

    Schwartz, Jennifer A; Olarte, Karen T; Michalek, Jamie L; Jandu, Gurjinder S; Michel, Sarah L J; Bruno, Vincent M

    2013-07-01

    Copper is an essential nutrient that is toxic to cells when present in excess. The fungal pathogen Candida albicans employs several mechanisms to survive in the presence of excess copper, but the molecular pathways that govern these responses are not completely understood. We report that deletion of GPA2, which specifies a G-protein α subunit, confers increased resistance to excess copper and propose that the increased resistance is due to a combination of decreased copper uptake and an increase in copper chelation by metallothioneins. This is supported by our observations that a gpa2Δ/Δ mutant has reduced expression of the copper uptake genes, CTR1 and FRE7, and a marked decrease in copper accumulation following exposure to high copper levels. Furthermore, deletion of GPA2 results in an increased expression of the copper metallothionein gene, CRD2. Gpa2p functions upstream in the cyclic AMP (cAMP)-protein kinase A (PKA) pathway to govern hyphal morphogenesis. The copper resistance phenotype of the gpa2Δ/Δ mutant can be reversed by artificially increasing the intracellular concentration of cAMP. These results provide evidence for a novel role of the PKA pathway in regulation of copper homeostasis. Furthermore, the connection between the PKA pathway and copper homeostasis appears to be conserved in the pathogen Cryptococcus neoformans but not in the nonpathogenic Saccharomyces cerevisiae. PMID:23584994

  11. Molecular and Histological Association Between Candida albicans from Oral Soft Tissue and Carious Dentine of HIV-Positive Children.

    PubMed

    Blignaut, Elaine; van Heerden, Willie F P

    2015-10-01

    Candida albicans and caries are frequently investigated among healthy and immunosuppressed individuals. The objective of this study was to demonstrate the presence of C. albicans on both oral soft and hard tissue and to investigate, at molecular level, the genetic subtype of the organism from the two oral sites. Tongue swabs and dentine scrapings from 362 HIV-positive children, referred for the extraction of carious primary teeth, were cultured on CHROMagar and identified to species level with ID32C. Histological staining of extracted carious teeth was also done. In patients with positive C. albicans cultures from both the tongue and carious dentine, DNA fingerprinting of such paired isolates was performed, using Southern blot hybridisation with the Ca3 probe. Yeasts were cultured from the tongue of 151 (41.7 %) individuals and 57 (37.7 %) simultaneously yielded positive C. albicans cultures from carious dentine. Nine different yeast spp. were identified from the tongue using the ID32C commercial system, but C. albicans was the only species recovered from carious dentine and histological investigation demonstrated fungal elements penetrated into the dentine and not limited to superficial debris on the floor of the cavity. Twelve of 13 paired isolates of C. albicans revealed identical fingerprinting patterns. The findings from this study demonstrated that in a particular individual, the same genetic subtype of C. albicans was capable of colonising both oral soft tissue and carious dentine. This renders carious teeth a constant source, or reservoir, of potentially infectious agents and, particularly among immunosuppressed individuals, should therefore not be left unattended. PMID:26153022

  12. A Novel Antifungal Is Active against Candida albicans Biofilms and Inhibits Mutagenic Acetaldehyde Production In Vitro

    PubMed Central

    Nieminen, Mikko T.; Novak-Frazer, Lily; Rautemaa, Vilma; Rajendran, Ranjith; Sorsa, Timo; Ramage, Gordon; Bowyer, Paul; Rautemaa, Riina

    2014-01-01

    The ability of C. albicans to form biofilms is a major virulence factor and a challenge for management. This is evident in biofilm-associated chronic oral-oesophageal candidosis, which has been shown to be potentially carcinogenic in vivo. We have previously shown that most Candida spp. can produce significant levels of mutagenic acetaldehyde (ACH). ACH is also an important mediator of candidal biofilm formation. We have also reported that D,L-2-hydroxyisocaproic acid (HICA) significantly inhibits planktonic growth of C. albicans. The aim of the present study was to investigate the effect of HICA on C. albicans biofilm formation and ACH production in vitro. Inhibition of biofilm formation by HICA, analogous control compounds or caspofungin was measured using XTT to measure biofilm metabolic activity and PicoGreen as a marker of biomass. Biofilms were visualised by scanning electron microscopy (SEM). ACH levels were measured by gas chromatography. Transcriptional changes in the genes involved in ACH metabolism were measured using RT-qPCR. The mean metabolic activity and biomass of all pre-grown (4, 24, 48 h) biofilms were significantly reduced after exposure to HICA (p<0.05) with the largest reductions seen at acidic pH. Caspofungin was mainly active against biofilms pre-grown for 4 h at neutral pH. Mutagenic levels (>40 µM) of ACH were detected in 24 and 48 h biofilms at both pHs. Interestingly, no ACH production was detected from D-glucose in the presence of HICA at acidic pH (p<0.05). Expression of genes responsible for ACH catabolism was up-regulated by HICA but down-regulated by caspofungin. SEM showed aberrant hyphae and collapsed hyphal structures during incubation with HICA at acidic pH. We conclude that HICA has potential as an antifungal agent with ability to inhibit C. albicans cell growth and biofilm formation. HICA also significantly reduces the mutagenic potential of C. albicans biofilms, which may be important when treating bacterial-fungal biofilm

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

    SciTech Connect

    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 organism 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.

  14. Chronic Candida albicans Meningitis in a 4-Year-Old Girl with a Homozygous Mutation in the CARD9 Gene (Q295X).

    PubMed

    Herbst, Martin; Gazendam, Roel; Reimnitz, Denise; Sawalle-Belohradsky, Julie; Groll, Andreas; Schlegel, Paul-Gerhardt; Belohradsky, Bernd; Renner, Ellen; Klepper, Jörg; Grimbacher, Bodo; Kuijpers, Taco; Liese, Johannes

    2015-09-01

    A 4-year-old Turkish girl of consanguineous parents was hospitalized for the evaluation of headaches and recurrent febrile episodes of unknown origin. Her medical history was unremarkable except for a few episodes of uncomplicated oral thrush. Meningitis was diagnosed, and Candida albicans was the only pathogen identified by polymerase chain reaction and culture. Despite systemic antifungal multidrug therapy, a prolonged course of 16 months of therapy was necessary to clear C. albicans from the cerebrospinal fluid. Molecular genetic analysis revealed a homozygous caspase recruitment domain 9 (CARD9) mutation (Q295X), which was reported to predispose to chronic mucocutaneous candidiasis. Immunologic workup excluded predisposing B-cell and T-cell defects. In addition, T cells producing interleukin-17 were repeatedly measured within the normal range. Analyses of neutrophils demonstrated normal nicotinamide adenine dinucleotide phosphate oxidase activity in response to various stimuli including Staphylococcus aureus and C. albicans. Additional neutrophilic functional testing, however, showed a decreased cytotoxicity to nonopsonized C. albicans, indicating an impaired killing mechanism against Candida spp. independent from the production of reactive oxygen species by the nicotinamide adenine dinucleotide phosphate oxidase system. Because this defect was only demonstrated in the absence of opsonins, it might especially predispose to chronic C. albicans infections in the central nervous system where opsonin concentrations are usually low. We, therefore, suggest that due to an additional neutrophil dependent defect CARD9 deficiency predisposes not only to chronic mucocutaneous candidiasis, but also to invasive chronic Candida infections, especially of the central nervous system. PMID:25933095

  15. Person-to-person transfer of Candida albicans in the spacecraft environment

    NASA Technical Reports Server (NTRS)

    Pierson, D. L.; Mehta, S. K.; Magee, B. B.; Mishra, S. K.

    1995-01-01

    We assessed the exchange of Candida albicans among crew members during 10 Space Shuttle missions. Throat, nasal, urine and faecal specimens were collected from 61 crew members twice before and once after space flights ranging from 7 to 10 days in duration; crews consisted of groups of five, six or seven men and women. Candida albicans was isolated at least once from 20 of the 61 subjects (33%). Candida strains were identified by restriction-fragment length polymorphism (RFLP) after digestion by the endonucleases EcoRI and HinfI; further discrimination was gained by Southern blot hybridization with the C. albicans repeat fragment 27A. Eighteen of the 20 Candida-positive crew members carried different strains of C. albicans in the specimens collected. Possible transfer of C. albicans between members of the same crew was demonstrated only once in the 10 missions studied. We conclude that the transfer of C. albicans among crew members during Space Shuttle flights is less frequent than had been predicted from earlier reports.

  16. Intra-amniotic Candida albicans infection induces mucosal injury and inflammation in the ovine fetal intestine

    PubMed Central

    Nikiforou, Maria; Jacobs, Esmee M.R.; Kemp, Matthew W.; Hornef, Mathias W.; Payne, Matthew S.; Saito, Masatoshi; Newnham, John P.; Janssen, Leon E.W.; Jobe, Alan H.; Kallapur, Suhas G.; Kramer, Boris W.; Wolfs, Tim G.A.M.

    2016-01-01

    Chorioamnionitis is caused by intrauterine infection with microorganisms including Candida albicans (C.albicans). Chorioamnionitis is associated with postnatal intestinal pathologies including necrotizing enterocolitis. The underlying mechanisms by which intra-amniotic C.albicans infection adversely affects the fetal gut remain unknown. Therefore, we assessed whether intra-amniotic C.albicans infection would cause intestinal inflammation and mucosal injury in an ovine model. Additionally, we tested whether treatment with the fungistatic fluconazole ameliorated the adverse intestinal outcome of intra-amniotic C.albicans infection. Pregnant sheep received intra-amniotic injections with 107 colony-forming units C.albicans or saline at 3 or 5 days before preterm delivery at 122 days of gestation. Fetuses were given intra-amniotic and intra-peritoneal fluconazole treatments 2 days after intra-amniotic administration of C.albicans. Intra-amniotic C.albicans caused intestinal colonization and invasive growth within the fetal gut with mucosal injury and intestinal inflammation, characterized by increased CD3+ lymphocytes, MPO+ cells and elevated TNF-α and IL-17 mRNA levels. Fluconazole treatment in utero decreased intestinal C.albicans colonization, mucosal injury but failed to attenuate intestinal inflammation. Intra-amniotic C.albicans caused intestinal infection, injury and inflammation. Fluconazole treatment decreased mucosal injury but failed to ameliorate C.albicans-mediated mucosal inflammation emphasizing the need to optimize the applied antifungal therapeutic strategy. PMID:27411776

  17. Intra-amniotic Candida albicans infection induces mucosal injury and inflammation in the ovine fetal intestine.

    PubMed

    Nikiforou, Maria; Jacobs, Esmee M R; Kemp, Matthew W; Hornef, Mathias W; Payne, Matthew S; Saito, Masatoshi; Newnham, John P; Janssen, Leon E W; Jobe, Alan H; Kallapur, Suhas G; Kramer, Boris W; Wolfs, Tim G A M

    2016-01-01

    Chorioamnionitis is caused by intrauterine infection with microorganisms including Candida albicans (C.albicans). Chorioamnionitis is associated with postnatal intestinal pathologies including necrotizing enterocolitis. The underlying mechanisms by which intra-amniotic C.albicans infection adversely affects the fetal gut remain unknown. Therefore, we assessed whether intra-amniotic C.albicans infection would cause intestinal inflammation and mucosal injury in an ovine model. Additionally, we tested whether treatment with the fungistatic fluconazole ameliorated the adverse intestinal outcome of intra-amniotic C.albicans infection. Pregnant sheep received intra-amniotic injections with 10(7) colony-forming units C.albicans or saline at 3 or 5 days before preterm delivery at 122 days of gestation. Fetuses were given intra-amniotic and intra-peritoneal fluconazole treatments 2 days after intra-amniotic administration of C.albicans. Intra-amniotic C.albicans caused intestinal colonization and invasive growth within the fetal gut with mucosal injury and intestinal inflammation, characterized by increased CD3(+) lymphocytes, MPO(+) cells and elevated TNF-α and IL-17 mRNA levels. Fluconazole treatment in utero decreased intestinal C.albicans colonization, mucosal injury but failed to attenuate intestinal inflammation. Intra-amniotic C.albicans caused intestinal infection, injury and inflammation. Fluconazole treatment decreased mucosal injury but failed to ameliorate C.albicans-mediated mucosal inflammation emphasizing the need to optimize the applied antifungal therapeutic strategy. PMID:27411776

  18. [A case report of pulmonary infiltration with eosinophilia syndrome induced by Candida albicans].

    PubMed

    Miyagawa, H; Yokota, S; Kajimoto, K; Makimoto, K; Sato, K; Nabe, M; Tada, S; Kimura, I

    1992-01-01

    A sixty six-year-old female who had been treated for bronchial asthma for about 25 years was admitted to the hospital with complaints of episodes of dyspnea, eosinophilia and infiltrative shadows in the chest X-ray film. An infiltrative shadow appeared to move from the left to the right lung field and finally formed a shadow of atelectasis in the middle field of the right lung. A sputum culture showed only Candida albicans. Allergic and immunologic examination revealed high IgE serum levels with specific IgE against Candida albicans in high titer, and Aspergillus fumigatus in low titer. The precipitating antibody was shown only against Candida antigen. Additionally, the blastogenic response to Candida antigen was high in comparison with other fungal antigens including Aspergillus fumigatus. The clinical features and laboratory findings of this patient were found to satisfy Rosenberg's criteria for allergic bronchopulmonary aspergillosis (ABPA), except for the existence of Candida albicans in place of Aspergillus species as the causative antigen. The pathogenesis of PIE syndrome has been studied and various allergic mechanisms against many antigens reported. In this patient Candida albicans could be playing the crucial role in the formation of PIE syndrome, which might be best described as allergic bronchopulmonary candidiasis (ABPC). PMID:1554325

  19. [In vitro nystatin sensitivity of vaginal isolates of Candida spp].

    PubMed

    Andreu, C M; Medina, Y E; Gonzáles, T C; Llanes, D M

    2001-01-01

    The minimum inhibitory concentration (MIC) of nistatine, one of the most used antifungal agents for this micosis, was determined in 68 Candida strains isolated from vaginal smears. Candida albicans represented 75% of the total strains whereas C. parapsilosis, C. krusei and C. glabrata were much less frequently found. The predisposing factors were pregnancy and antibacterial treatment whereas leukorrhea and itching were the prevailing symptoms in most of the cases. MIC values from the use of a broth dilution method ranged from 0,5-8mg/mL and the geometric mean was 1.36mg/ mL. For C. albicans, MIC was 4mg/mL due to two strains that showed the highest MIC values (8 mg/mL). Similarly, the strains showed low MIC values, this means that therapeutic failures are not inherent to the emergence of resistant strains. PMID:15846923

  20. Imaging morphogenesis of Candida albicans during infection in a live animal

    NASA Astrophysics Data System (ADS)

    Mitra, Soumya; Dolan, Kristy; Foster, Thomas H.; Wellington, Melanie

    2010-01-01

    Candida albicans is an opportunistic human fungal pathogen that requires an intact host immune response to prevent disease. Thus, studying host-pathogen interactions is critical to understanding and preventing this disease. We report a new model infection system in which ongoing C. albicans infections can be imaged at high spatial resolution in the ears of living mice. Intradermal inoculation into mouse ears with a C. albicans strain expressing green fluorescent protein results in systemic C. albicans infection that can be imaged in vivo using confocal microscopy. We observed filamentous growth of the organism in vivo as well as formation of microabscesses. This model system will allow us to gain significant new information about C. albicans pathogenesis through studies of host-C. albicans interactions in the native environment.

  1. Cilofungin (LY121019), an antifungal agent with specific activity against Candida albicans and Candida tropicalis.

    PubMed Central

    Hall, G S; Myles, C; Pratt, K J; Washington, J A

    1988-01-01

    Cilofungin (LY121019) is an antifungal agent that interferes with beta-glucan synthesis in the cells walls of fungi. The activity of this agent against 256 clinical isolates of yeasts was determined. It was found to be very active in vitro against Candida albicans (MIC for 90% of isolates [MIC90], less than or equal to 0.31 microgram/ml; minimal fungicidal concentration for 90% of isolates [MFC90], less than or equal to 0.31 micrograms/ml) and C. tropicalis (MIC90, less than or equal to 0.31 microgram/ml; MFC90, less than or equal to 0.31 microgram/ml) and moderately active against Torulopsis glabrata (MIC90 and MFC90, less than or equal to 20 micrograms/ml). All C. parapsilosis, Cryptococcus, and Saccharomyces cerevisiae strains were resistant. The activity of cilofungin was affected by medium and inoculum size. Antibiotic medium no. 3 was used as the standard medium. Isolates of C. albicans and C. tropicalis demonstrated a paradoxical effect in Sabouraud dextrose broth and yeast nitrogen base broth in that growth was partially inhibited at MICs equivalent to those in antibiotic medium no. 3, but growth continued, in many instances, throughout all concentrations tested. There was decreased activity of cilofungin with inocula greater than 10(5) CFU/ml. The temperature and duration of incubation did not affect its activity. Images PMID:3058017

  2. Effectiveness of Photodynamic Therapy for the Inactivation of Candida spp. on Dentures: In Vitro Study

    PubMed Central

    Mima, Ewerton Garcia de Oliveira; Ribeiro, Daniela Garcia; Dovigo, Livia Nordi; Vergani, Carlos Eduardo; Bagnato, Vanderlei Salvador

    2011-01-01

    Abstract Objective: This in vitro study evaluated the effectiveness of photodynamic therapy (PDT) for the inactivation of different species of Candida on maxillary complete dentures. Background data: The treatment of denture stomatitis requires the inactivation of Candida spp. on dentures. PDT has been reported as an effective method for Candida inactivation. Methods: Reference strains of C. albicans, C. glabrata, C. tropicalis, C. dubliniensis and C. krusei were tested. Thirty-four dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated with one of the strains and incubated at 37°C for 24 h. Dentures submitted to PDT (P+L+) were individually sprayed with 50 mg/L of Photogem® (PS) and, after 30 min, illuminated by LED light for 26 min (37.5 J/cm2). Additional dentures were treated only with PS (P+L-) or light (P-L+) or neither (P-L-). Samples of serial dilutions were spread on Sabouraud dextrose agar and incubated at 37°C for 48 h. The colonies were counted and the values of log (cfu/mL) were analyzed by Kruskall-Wallis and Dunn tests (p<0.05). Results: For all species of Candida, PDT resulted in significant reduction (p<0.05) of cfu/mL values from dentures when compared with P-L- (reductions from 1.73 to 3.99 log10). Significant differences (p<0.05), but lower reductions, were also observed for P+L- and P-L+when compared with P-L- for some species of Candida. Conclusions: PDT was an effective method for reducing Candida spp. on dentures. PMID:21916614

  3. Evaluation of anti-Candida potential of geranium oil constituents against clinical isolates of Candida albicans differentially sensitive to fluconazole: inhibition of growth, dimorphism and sensitization.

    PubMed

    Zore, Gajanan B; Thakre, Archana D; Rathod, V; Karuppayil, S Mohan

    2011-07-01

    Fluconazole (FLC) susceptibility of isolates of Candida spp., (n = 42) and efficacy as well as mechanism of anti-Candida activity of three constituents of geranium oil is evaluated in this study. No fluconazole resistance was observed among the clinical isolates tested, however 22% were susceptible-dose-dependent (S-DD) [minimal inhibitory concentration (MIC) ≥ 16 μg ml(-1)] and a standard strain of C. albicans ATCC 10231 was resistant (≥ 64 μg ml(-1)). Geraniol and geranyl acetate were equally effective, fungicidal at 0.064% v/v concentrations i.e. MICs (561 μg ml(-1) and 584 μg ml(-1) respectively) and killed 99.9% inoculum within 15 and 30 min of exposures respectively. Citronellol was least effective and fungistatic. C. albicans dimorphism (Y → H) was highly sensitive to geranium oil constituents tested (IC50 approximately 0.008% v/v). Geraniol, geranyl acetate and citronellol brought down MICs of FLC by 16-, 32- and 64-fold respectively in a FLC-resistant strain. Citronellol and geraniol arrested cells in G1 phase while geranyl acetate in G2-M phase of cell cycle at MIC(50). In vitro cytotoxicity study revealed that geraniol, geranyl acetate and citronellol were non-toxic to HeLa cells at MICs of the C. albicans growth. Our results indicate that two of the three geranium oil constituents tested exhibit excellent anti-Candida activity and significant synergistic activity with fluconazole. PMID:20337938

  4. Performance of commercial latex agglutination tests for the differentiation of Candida dubliniensis and Candida albicans in routine diagnostics.

    PubMed

    Chryssanthou, E; Fernandez, V; Petrini, B

    2007-11-01

    Candida dubliniensis is phenotypically similar to Candida albicans and may therefore be underdiagnosed in the clinical microbiology laboratory. The performance of Bichro-Dubli latex agglutination test for rapid species identification of C. dubliniensis was prospectively evaluated on 111 vaginal and 118 respiratory isolates. These had presumptively been identified as C. albicans/C. dubliniensis by their green colonies on CHROMagar Candida plates. Bichro-Dubli test identifed 2 (1.8%) vaginal and 6 (5.1%) respiratory isolates as C. dubliniensis. The test was also positive for 37 C. dubliniensis control strains characterised by 18S-28S DNA-sequencing. Bichro-Dubli test is thus a sensitive and accurate tool for rapid diagnostics in routine laboratories. PMID:18092961

  5. Delicate Metabolic Control and Coordinated Stress Response Critically Determine Antifungal Tolerance of Candida albicans Biofilm Persisters

    PubMed Central

    Li, Peng; Alpi, Emanuele; Vizcaino, Juan A.

    2015-01-01

    Candida infection has emerged as a critical health care burden worldwide, owing to the formation of robust biofilms against common antifungals. Recent evidence shows that multidrug-tolerant persisters critically account for biofilm recalcitrance, but their underlying biological mechanisms are poorly understood. Here, we first investigated the phenotypic characteristics of Candida biofilm persisters under consecutive harsh treatments of amphotericin B. The prolonged treatments effectively killed the majority of the cells of biofilms derived from representative strains of Candida albicans, Candida glabrata, and Candida tropicalis but failed to eradicate a small fraction of persisters. Next, we explored the tolerance mechanisms of the persisters through an investigation of the proteomic profiles of C. albicans biofilm persister fractions by liquid chromatography-tandem mass spectrometry. The C. albicans biofilm persisters displayed a specific proteomic signature, with an array of 205 differentially expressed proteins. The crucial enzymes involved in glycolysis, the tricarboxylic acid cycle, and protein synthesis were markedly downregulated, indicating that major metabolic activities are subdued in the persisters. It is noteworthy that certain metabolic pathways, such as the glyoxylate cycle, were able to be activated with significantly increased levels of isocitrate lyase and malate synthase. Moreover, a number of important proteins responsible for Candida growth, virulence, and the stress response were greatly upregulated. Interestingly, the persisters were tolerant to oxidative stress, despite highly induced intracellular superoxide. The current findings suggest that delicate metabolic control and a coordinated stress response may play a crucial role in mediating the survival and antifungal tolerance of Candida biofilm persisters. PMID:26195524

  6. An Optimized Lock Solution Containing Micafungin, Ethanol and Doxycycline Inhibits Candida albicans and Mixed C. albicans – Staphyloccoccus aureus Biofilms

    PubMed Central

    Lown, Livia; Peters, Brian M.; Walraven, Carla J.; Noverr, Mairi C.; Lee, Samuel A.

    2016-01-01

    Candida albicans is a major cause of catheter-related bloodstream infections and is associated with high morbidity and mortality. Due to the propensity of C. albicans to form drug-resistant biofilms, the current standard of care includes catheter removal; however, reinsertion may be technically challenging or risky. Prolonged exposure of an antifungal lock solution within the catheter in conjunction with systemic therapy has been experimentally attempted for catheter salvage. Previously, we demonstrated excellent in vitro activity of micafungin, ethanol, and high-dose doxycycline as single agents for prevention and treatment of C. albicans biofilms. Thus, we sought to investigate optimal combinations of micafungin, ethanol, and/or doxycycline as a lock solution. We performed two- and three-drug checkerboard assays to determine the in vitro activity of pairwise or three agents in combination for prevention or treatment of C. albicans biofilms. Optimal lock solutions were tested for activity against C. albicans clinical isolates, reference strains and polymicrobial C. albicans-S. aureus biofilms. A solution containing 20% (v/v) ethanol, 0.01565 μg/mL micafungin, and 800 μg/mL doxycycline demonstrated a reduction of 98% metabolic activity and no fungal regrowth when used to prevent fungal biofilm formation; however there was no advantage over 20% ethanol alone. This solution was also successful in inhibiting the regrowth of C. albicans from mature polymicrobial biofilms, although it was not fully bactericidal. Solutions containing 5% ethanol with low concentrations of micafungin and doxycycline demonstrated synergistic activity when used to prevent monomicrobial C. albicans biofilm formation. A combined solution of micafungin, ethanol and doxycycline is highly effective for the prevention of C. albicans biofilm formation but did not demonstrate an advantage over 20% ethanol alone in these studies. PMID:27428310

  7. Effects of simulated microgravity by RCCS on the biological features of Candida albicans.

    PubMed

    Jiang, Wenjun; Xu, Bingxin; Yi, Yong; Huang, Yuling; Li, Xiao-Ou; Jiang, Fuquan; Zhou, Jinlian; Zhang, Jianzhong; Cui, Yan

    2014-01-01

    During the spaceflight, a wide variety of microorganisms may be carried to the outer space by astronauts and aviation component. The yeast Candida albicans is an important opportunistic pathogen responsible for a variety of cutaneous and systemic human infections in human body, and the yeast cell itself could be affected by various stressful environmental factors including the weightless environment. We evaluated the effects of simulated microgravity on biological features of Candida albicans using the rotary cell culture system (RCCS). The growth curves of Candida albicans cultured in RCCS were recorded by spectrophotometer, the morphogenic switches were observed by optical microscope, and the viability of cells exposed to the various concentrations of fluconazole solution was assayed by flow cytometry at 7th, 14th and 21st day of experiment. The results showed that Candida albicans SC5314 under modeled microgravity were manifested as the growth curves leftward-shifted, lag phase shortened, along with logarithmic phase and stationary phase forwarded (P < 0.05). The simulated microgravity increased the growth rate and mycelia formation of Candida albicans. A statistically significant decrease in viability was detected in cells cultured for 7 d, 14 d and 21 d in group of simulated microgravity compared with the control group (P < 0.05). The increase of exposure time to simulate microgravity resulted in the decrease of viability of cells accordingly in same drug concentration compared with the control group. The study demonstrated that the three weeks' simulated microgravity in RCCS had a noticeable affect on the growth status of mycelia and spores and the morphogenic switches of Candida albicans, meanwhile, the yeast cells under simulated microgravity showed an increased antifungal susceptibility to fluconazole. PMID:25120754

  8. Reduced inhibition of Candida albicans adhesion by saliva from patients receiving oral cancer therapy.

    PubMed Central

    Umazume, M; Ueta, E; Osaki, T

    1995-01-01

    The effect of saliva on the adhesion of Candida albicans to epithelial cells was examined in vitro by using saliva from healthy controls and patients with oral squamous cell carcinoma. The adhesion of C. albicans to established epithelial tumor cells was reduced by 40% by salivary treatment of the C. albicans or epithelial cells. The inhibitory activity of saliva was almost completely abolished by anti-secretory immunoglobulin A antibody, concanavalin A, and mannose. Compared with saliva from healthy individuals, that from patients who had received chemoradiotherapy for oral carcinoma showed reduced suppression of C. albicans adhesion, which accompanied decreased salivary secretory immunoglobulin A and lactoferrin concentrations. A greater number of C. albicans cells adhered to buccal cells obtained from patients who had received chemoradiotherapy than to those from healthy individuals. Treatment of either epithelial cells or C. albicans with anticancer drugs induced an increase in adherence of epithelial cells and yeast cells. In contrast, concanavalin A- and mannose-pretreated C. albicans exhibited reduced adhesion to epithelial cells. No further decrease of C. albicans adhesion was observed when both epithelial cells and yeast phase C. albicans were treated with mannose. In conclusion, the inhibition of C. albicans adhesion by saliva depends largely on mannose residues on salivary glycoproteins and mannose is one of the binding ligands on both C. albicans and epithelial cells. In addition, anticancer therapy may induce oral C. albicans overgrowth by decreasing salivation and the concentrations of glycoproteins in saliva inhibiting C. albicans adhesion and by increasing the adhesive properties of both C. albicans and oral epithelial cells. PMID:7714204

  9. RAPID IDENTIFICATION OF CANDIDA ALBICANS DIRECTLY FROM YEAST POSITIVE BLOOD CULTURE BOTTLES BY FLUORESCENCE IN SITU HYBRIDIZATION USING PNA PROBES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new fluorescence in situ hybridization (FISH) method using peptide nucleic acid (PNA) probes for identification of Candida albicans directly from yeast-positive blood culture bottles is described. The test (C. albicans PNA FISH) is based on a fluorescein-labeled PNA probe targeting C. albicans 26...

  10. 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

  11. Cerebral candidiasis: case report of brain abscess secondary to Candida albicans, and review of literature

    PubMed Central

    Black, Joseph T.

    1970-01-01

    A patient with a brain abscess due to Candida albicans is reported. This patient had three episodes of systemic candidiasis in spite of the fact that she had no underlying debilitating disease and had never received prior antibiotic or adrenocortical steroid therapy. A review of the literature reveals 42 cases of central nervous system Candida albicans infection. The salient features of these cases are tabulated and discussed. The clinical features, pathology, pathogenesis, treatment, and aetiology of cerebral candidiasis are also discussed. Images PMID:5531906

  12. The synthesis and synergistic antifungal effects of chalcones against drug resistant Candida albicans.

    PubMed

    Wang, Yuan-Hua; Dong, Huai-Huai; Zhao, Fei; Wang, Jie; Yan, Fang; Jiang, Yuan-Ying; Jin, Yong-Sheng

    2016-07-01

    To identify effective and low toxicity synergistic antifungal compounds, 24 derivatives of chalcone were synthesized to restore the effectiveness of fluconazole against fluconazole-resistant Candida albicans. The minimal inhibitory concentration (MIC80) and the fractional inhibitory concentration index (FICI) of the antifungal synergist fluconazole were measured against fluconazole-resistant Candida albicans. This was done via methods established by the clinical and laboratory standards institute (CLSI). Of the synthesized compounds, 2'-hydroxy-4'-methoxychalcone (8) exhibited the most potent in vitro (FICI=0.007) effects. The structure activity relationship of the compounds are then discussed. PMID:27210436

  13. A Monoclonal Antibody Directed against a Candida albicans Cell Wall Mannoprotein Exerts Three Anti-C. albicans Activities

    PubMed Central

    Moragues, María D.; Omaetxebarria, Miren J.; Elguezabal, Natalia; Sevilla, María J.; Conti, Stefania; Polonelli, Luciano; Pontón, José

    2003-01-01

    Antibodies are believed to play a role in the protection against Candida albicans infections by a number of mechanisms, including the inhibition of adhesion or germ tube formation, opsonization, neutralization of virulence-related enzymes, and direct candidacidal activity. Although some of these biological activities have been demonstrated individually in monoclonal antibodies (MAbs), it is not clear if all these anti-C. albicans activities can be displayed by a single antibody. In this report, we characterized a monoclonal antibody raised against the main target of salivary secretory immunoglobulin A in the cell wall of C. albicans, which exerts three anti-C. albicans activities: (i) inhibition of adherence to HEp-2 cells, (ii) inhibition of germination, and (iii) direct candidacidal activity. MAb C7 reacted with a proteinic epitope from a mannoprotein with a molecular mass of >200 kDa predominantly expressed on the C. albicans germ tube cell wall surface as well as with a number of antigens from Candida lusitaniae, Cryptococcus neoformans, Aspergillus fumigatus, and Scedosporium prolificans. MAb C7 caused a 31.1% inhibition in the adhesion of C. albicans to HEp-2 monolayers and a 55.3% inhibition in the adhesion of C. albicans to buccal epithelial cells, produced a 38.5% decrease in the filamentation of C. albicans, and exhibited a potent fungicidal effect against C. albicans, C. lusitaniae, Cryptococcus neoformans, A. fumigatus, and S. prolificans, showing reductions in fungal growth ranging from 34.2 to 88.7%. The fungicidal activity showed by MAb C7 seems to be related to that reported by antibodies mimicking the activity of a killer toxin produced by the yeast Pichia anomala, since one of these MAbs also reacted with the C. albicans mannoprotein with a molecular mass of >200 kDa. Results presented in this study support the concept of a family of microbicidal antibodies that could be useful in the treatment of a wide range of microbial infections when used

  14. Systemic Staphylococcus aureus infection mediated by Candida albicans hyphal invasion of mucosal tissue

    PubMed Central

    Schlecht, Lisa Marie; Peters, Brian M.; Krom, Bastiaan P.; Freiberg, Jeffrey A.; Hänsch, Gertrud M.; Filler, Scott G.

    2015-01-01

    Candida albicans and Staphylococcus aureus are often co-isolated in cases of biofilm-associated infections. C. albicans can cause systemic disease through morphological switch from the rounded yeast to the invasive hyphal form. Alternatively, systemic S. aureus infections arise from seeding through breaks in host epithelial layers although many patients have no documented portal of entry. We describe a novel strategy by which S. aureus is able to invade host tissue and disseminate via adherence to the invasive hyphal elements of Candida albicans. In vitro and ex vivo findings demonstrate a specific binding of the staphylococci to the candida hyphal elements. The C. albicans cell wall adhesin Als3p binds to multiple staphylococcal adhesins. Furthermore, Als3p is required for C. albicans to transport S. aureus into the tissue and cause a disseminated infection in an oral co-colonization model. These findings suggest that C. albicans can facilitate the invasion of S. aureus across mucosal barriers, leading to systemic infection in co-colonized patients. PMID:25332378

  15. Inhibitory Effect of Alpha-Mangostin on Adhesion of Candida albicans to Denture Acrylic

    PubMed Central

    Kaomongkolgit, Ruchadaporn; Jamdee, Kusuma

    2015-01-01

    Objective: Candida-associated denture stomatitis is a very common disease affecting denture wearers. It is characterized by the presence of yeast biofilm on the denture, primarily associated with C. albicans. The investigation of agents that can reduce C. albicans adhesion may represent a significant advancement in the prevention and treatment of this disease. This study aims to investigate the effect of alpha-mangostin on the in vitro adhesion of C. albicans to denture acrylic and germ tube formation by C. albicans and to compare its activity with clotrimazole which is a topical antifungal agent commonly used for the treatment of Candida-associated denture stomatitis. Materials and Methodology: Alpha-mangostin was extracted by thin layer chromatography. The effect of alpha-mangostin on adhesion of C. albicans to denture acrylic was determined by using a colorimetric tetrazolium assay and germ tube formation by C. albicans was determined by using the counting chamber. Results: A significant reduction of C. albicans adhesion to denture acrylic was evident after exposure to 2,000 µg/ml of alpha-mangostin for only 15 min. In addition, the 2,000 µg/ml of the alpha-mangostin-treated C. albicans had a reduced ability for germ tube formation. These inhibitory effects of alpha-mangostin were as effective as clotrimazole. Conclusion: Alpha-mangostin has antifungal property against C. albicans by inhibiting the adhesion to denture acrylic and germ tube formation in vitro. These results suggest the potential application of alpha-mangostin as a topical medication or a natural oral hygiene product for treatment of Candida-associated denture stomatitis. PMID:26962371

  16. Presumptive identification of Candida species other than C. albicans, C. krusei, and C. tropicalis with the chromogenic medium CHROMagar Candida

    PubMed Central

    Hospenthal, Duane R; Beckius, Miriam L; Floyd, Karon L; Horvath, Lynn L; Murray, Clinton K

    2006-01-01

    Background CHROMagar Candida (CaC) is increasingly being reported as a medium used to differentiate Candida albicans from non-albicans Candida (NAC) species. Rapid identification of NAC can assist the clinician in selecting appropriate antifungal therapy. CaC is a differential chromogenic medium designed to identify C. albicans, C. krusei, and C. tropicalis based on colony color and morphology. Some reports have proposed that CaC can also reliably identify C. dubliniensis and C. glabrata. Methods We evaluated the usefulness of CaC in the identification of C. dubliniensis, C. famata, C. firmetaria, C. glabrata, C. guilliermondii, C. inconspicua, C. kefyr, C. lipolytica, C. lusitaniae, C. norvegensis, C. parapsilosis, and C. rugosa. Results Most NAC produced colonies that were shades of pink, lavender, or ivory. Several isolates of C. firmetaria and all C. inconspicua produced colonies difficult to differentiate from C. krusei. Most C. rugosa isolates produced unique colonies with morphology like C. krusei except in a light blue-green color. C. glabrata isolates produced small dark violet colonies that could be differentiated from the pink and lavender colors produced by other species. All seventeen isolates of C. dubliniensis produced green colonies similar to those produced by C. albicans. Conclusion C. glabrata and C. rugosa appear distinguishable from other species using CaC. Some NAC, including C. firmetaria and C. inconspicua, could be confused with C. krusei using this medium. PMID:16390552

  17. Essential Oils, Silver Nanoparticles and Propolis as Alternative Agents Against Fluconazole Resistant Candida albicans, Candida glabrata and Candida krusei Clinical Isolates.

    PubMed

    Szweda, Piotr; Gucwa, Katarzyna; Kurzyk, Ewelina; Romanowska, Ewa; Dzierżanowska-Fangrat, Katarzyna; Zielińska Jurek, Anna; Kuś, Piotr Marek; Milewski, Sławomir

    2015-06-01

    Development of effective and safe therapeutic treatment of fungal infections remains one of the major challenge for modern medicine. The aim of presented investigation was to analyze the in vitro antifungal activity of selected essential oils, ethanolic extracts of propolis and silver nanoparticles dropped on TiO2 against azole-resistant C. albicans (n = 20), C. glabrata (n = 14) and C. krusei (n = 10) clinical isolates. Among tested essential oils, the highest activity has definitely been found in the case of the oil isolated from the bark of Cinnamomum cassia, with MIC and MFC values for all tested strains in the range of 0.0006-0.0097 % (v/v) and 0.0012-0.019 % (v/v), respectively. High activity was also observed for the Lemon, Basil, Thyme, Geranium and Clove (from buds) essential oils. Significant differences in fungicidal activity have been observed in the case of four tested propolis samples. Only one of them revealed high activity, with MFC values in the range from 0.156 to 1.25 % (v/v). Satisfactory fungicidal activity, against C. albicans and C. glabrata isolates, was also observed in the case of silver nanoparticles, however C. krusei isolates were mostly resistant. We also revealed that constituents of most of essential oils and propolis as well as silver nanoparticles are not substrates for drug transporters, which belong to the most important factors affecting resistance of Candida spp. clinical isolates to many of conventional antimycotics. To conclude, the results of our investigation revealed that essential oils, propolis and silver nanoparticles represent high potential for controlling and prevention candidiasis. PMID:25805904

  18. Phospholipid biosynthesis in Candida albicans: Regulation by the precursors inositol and choline

    SciTech Connect

    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. Possible explanations for the observed differences in regulation are discussed.

  19. Influence of radiation therapy on oral Candida albicans colonization: a quantitative assessment

    SciTech Connect

    Rossie, K.M.; Taylor, J.; Beck, F.M.; Hodgson, S.E.; Blozis, G.G.

    1987-12-01

    An increase in quantity of oral Candida albicans was documented in patients receiving head and neck radiation therapy during and after therapy, as assessed by an oral-rinse culturing technique. The amount of the increase was greater in denture wearers and directly related to increasing radiation dose and increasing volume of parotid gland included in the radiation portal. A significant number of patients who did not carry C. albicans prior to radiation therapy developed positive cultures by 1 month after radiation therapy. The percentage of patients receiving head and neck radiation therapy who carried C. albicans prior to radiation therapy did not differ significantly from matched dental patient controls.

  20. 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

  1. Use of immunoblotting to identify antigenic differences between the yeast and mycelial phases of Candida albicans.

    PubMed Central

    Burnie, J P; Matthews, R C; Fox, A; Tabaqchali, S

    1985-01-01

    Western blotting was applied to the analysis of Candida albicans in the yeast and mycelial phases in an attempt to recognise mycelial specific antigens which might be of serodiagnostic value. The antisera were prepared in rabbits by immunising them with pressates of C albicans type A NCTC 3153 in the yeast phase or the mycelial phase. These were blotted against C albicans in the yeast and mycelial phases and the yeast phase of C parapsilosis, C krusei, C tropicalis, and Torulopsis glabrata. Cross reactivity was greatest against C parapsilosis. One yeast specific mannoprotein was identified with a molecular weight of 49 000. No mycelial specific antigens could be identified. Images PMID:3891792

  2. Micafungin triggers caspase-dependent apoptosis in Candida albicans and Candida parapsilosis biofilms, including caspofungin non-susceptible isolates.

    PubMed

    Shirazi, F; Kontoyiannis, D P

    2015-01-01

    Candida biofilms play an important role in infections associated with medical devices and are resistant to antifungals. We hypothesized that the echinocandin micafungin (MICA) exerts an enhanced antifungal activity against caspofungin (CAS)-susceptible (CAS-S) and CAS-non-susceptible (CAS-NS) Candida albicans and Candida parapsilosis which is at least in part through apoptosis, even in the biofilm environment. Apoptosis was characterized by detecting reactive oxygen species (ROS) accumulation, depolarization of mitochondrial membrane potential (MMP), DNA fragmentation, lack of plasma membrane integrity, and metacaspase activation following exposure of Candida biofilm to MICA for 3h at 37°C in RPMI 1640 medium. The minimum inhibitory concentration was higher for CAS (2.0-16.0 μg/mL) than for MICA (1.0-8.0 μg/mL) for Candida biofilms. Elevated intracellular ROS levels and depolarization of MMP was evident in CAS-S C. albicans (3.0-4.2 fold) and C. parapsilosis (4.8-5.4 fold) biofilms compared with CAS-NS (1.2 fold) after exposure to MICA (0.25x-1xMIC). Elevated intracellular ROS levels and depolarization of MMP was evident in CAS-S C. albicans (3.0-4.2 fold) and C. parapsilosis (4.8-5.4 fold) biofilms compared with CAS-NS (1.2 fold) after exposure to MICA (0.25x-1xMIC). Finally higher ß-1, 3 glucan levels were seen in sessile cells compared to planktonic cells, especially in CAS-NS strains. MICA treatment might induce a metacaspase-dependent apoptotic process in biofilms of both CAS-S C. albicans and C. parapsilosis, and to some degree in CAS-NS strains. PMID:26065323

  3. CX3CL1 expression induced by Candida albicans in oral fibroblasts.

    PubMed

    Ohta, Kouji; Nishi, Hiromi; Fukui, Akiko; Shigeishi, Hideo; Takechi, Masaaki; Kamata, Nobuyuki

    2010-11-01

    Oral fibroblasts as well as keratinocytes are thought to influence host inflammatory responses against Candida albicans. However, little is known about chemokine expressions in oral fibroblasts against C. albicans infection. We therefore examined whether C. albicans induced several chemokines including fractalkine/CX3CL1 (CX3CL1), a unique chemokine that has properties of both chemoattractants and adhesion molecules, in fibroblasts and keratinocytes. The addition of C. albicans live cells to human immortalized oral keratinocytes (RT7) resulted in increases in the mRNA levels of multiple chemokines, but not of CX3CL1. In contrast, live and heat-killed C. albicans caused an increase in CX3CL1 mRNA and protein expression in human immortalized oral fibroblasts (GT1). CX3CL1 mRNA expression in GT1 cells was also enhanced by stimulation with a nonalbicans species of Candida. Further, the CX3CL1 chemokine domain showed antifungal activity against C. albicans. CX3CL1 secreted by oral fibroblasts appears to play an important role in the oral immune response to C. albicans infection. PMID:20880200

  4. Gene expression profile of THP-1 cells treated with heat-killed Candida albicans

    PubMed Central

    Hu, Zhi-De; Wei, Ting-Ting; Tang, Qing-Qin; Ma, Ning; Wang, Li-Li; Qin, Bao-Dong; Yin, Jian-Rong

    2016-01-01

    Background Mechanisms under immune response against Candida albicans (C. albicans) remain largely unknown. To better understand the mechanisms of innate immune response against C. albicans, we analyzed the gene expression profile of THP-1 cells stimulated with heat-killed C. albicans. Methods THP-1 cells were stimulated with heat-killed C. albicans for 9 hours at a ratio of 1:1, and gene expression profile of the cells was analyzed using Whole Human Genome Oligo Microarray. Differentially expressed genes were defined as change folds more than 2 and with statistical significance. Gene ontology (GO) and pathway analysis were used to systematically identify biological connections of differentially expressed genes, as well as the pathways associated with the immune response against C. albicans. Results A total of 355 genes were up-regulated and 715 genes were down-regulated significantly. The up-regulated genes were particularly involved in biological process of RNA processing and pathway of the spliceosome. In case of down-regulated genes, the particularly involved immune-related pathways were G-protein coupled receptor signaling pathway, calcium signaling pathway, MAPK signaling pathway and Ras pathway. Conclusions We depict the gene expression profile of heat-killed C. albicans stimulated THP-1 cells, and identify the major pathways involved in immune response against C. albicans. These pathways are potential candidate targets for developing anti-C. albicans agent. PMID:27275483

  5. Human Epithelial Cells Discriminate between Commensal and Pathogenic Interactions with Candida albicans

    PubMed Central

    Rast, Timothy J.; Kullas, Amy L.; Southern, Peter J.; Davis, Dana A.

    2016-01-01

    The commensal fungus, Candida albicans, can cause life-threatening infections in at risk individuals. C. albicans colonizes mucosal surfaces of most people, adhering to and interacting with epithelial cells. At low concentrations, C. albicans is not pathogenic nor does it cause epithelial cell damage in vitro; at high concentrations, C. albicans causes mucosal infections and kills epithelial cells in vitro. Here we show that while there are quantitative dose-dependent differences in exposed epithelial cell populations, these reflect a fundamental qualitative difference in host cell response to C. albicans. Using transcriptional profiling experiments and real time PCR, we found that wild-type C. albicans induce dose-dependent responses from a FaDu epithelial cell line. However, real time PCR and Western blot analysis using a high dose of various C. albicans strains demonstrated that these dose-dependent responses are associated with ability to promote host cell damage. Our studies support the idea that epithelial cells play a key role in the immune system by monitoring the microbial community at mucosal surfaces and initiating defensive responses when this community is dysfunctional. This places epithelial cells at a pivotal position in the interaction with C. albicans as epithelial cells themselves promote C. albicans stimulated damage. PMID:27088599

  6. Effect of Nitric Oxide on the Antifungal Activity of Oxidative Stress and Azoles Against Candida albicans.

    PubMed

    Li, De-Dong; Yang, Chang-Chun; Liu, Ping; Wang, Yan; Sun, Yan

    2016-06-01

    Nitric oxide (NO) is a small molecule with a wide range of biological activities in mammalian and bacteria. However, the role of NO in fungi, especially Candida albicans, is not clear. In this study, we confirmed the generation of endogenous NO in C. albicans, and found that the production of endogenous NO in C. albicans was associated with nitric oxide synthase pathway. Our results further indicated that the production of endogenous NO in C. albicans was reduced under oxidative stress such as menadione or H2O2 treatment. Meanwhile, exogenous NO donor, sodium nitroprusside (SNP), synergized with H2O2 against C. albicans. Interestingly, SNP could inhibit the antifungal effect of azoles against C. albicans in vitro, suggesting that NO might be involved in the resistance of C. albicans to antifungals. Collectively, this study demonstrated the production of endogenous NO in C. albicans, and indicated that NO may play an important role in the response of C. albicans to oxidative stress and azoles. PMID:27570314

  7. Antimicrobial blue light therapy for Candida albicans burn infection in mice

    NASA Astrophysics Data System (ADS)

    Zhang, Yunsong; Wang, Yucheng; Murray, Clinton K.; Hamblin, Michael R.; Gu, Ying; Dai, Tianhong

    2015-05-01

    In this preclinical study, we investigated the utility of antimicrobial blue light therapy for Candida albicans infection in acutely burned mice. A bioluminescent strain of C. albicans was used. The susceptibilities to blue light inactivation were compared between C. albicans and human keratinocyte. In vitro serial passaging of C. albicans on blue light exposure was performed to evaluate the potential development of resistance to blue light inactivation. A mouse model of acute thermal burn injury infected with the bioluminescent strain of C. albicans was developed. Blue light (415 nm) was delivered to mouse burns for decolonization of C. albicans. Bioluminescence imaging was used to monitor in real time the extent of fungal infection in mouse burns. Experimental results showed that C. albicans was approximately 42-fold more susceptible to blue light inactivation in vitro than human keratinocyte (P=0.0022). Serial passaging of C. albicans on blue light exposure implied a tendency for the fungal susceptibility to blue light inactivation to decrease with the numbers of passages. Blue light reduced fungal burden by over 4-log10 (99.99%) in acute mouse burns infected with C. albicans in comparison to infected mouse burns without blue light therapy (P=0.015).

  8. Photodynamic Inactivation of Candida albicans with Imidazoacridinones: Influence of Irradiance, Photosensitizer Uptake and Reactive Oxygen Species Generation

    PubMed Central

    Taraszkiewicz, Aleksandra; Szewczyk, Grzegorz; Sarna, Tadeusz; Bielawski, Krzysztof P.; Nakonieczna, Joanna

    2015-01-01

    The increasing applicability of antifungal treatments, the limited range of available drug classes and the emergence of drug resistance in Candida spp. suggest the need for new treatment options. To explore the applicability of C. albicans photoinactivation, we examined nine structurally different imidazoacridinone derivatives as photosensitizing agents. The most effective derivatives showed a >104-fold reduction of viable cell numbers. The fungicidal action of the three most active compounds was compared at different radiant powers(3.5 to 63 mW/cm2), and this analysis indicated that 7 mW/cm2 was the most efficient. The intracellular accumulation of these compounds in fungal cells correlated with the fungicidal activity of all 9 derivatives. The lack of effect of verapamil, an inhibitor targeting Candida ABC efflux pumps, suggests that these imidazoacridinones are not substrates for ABC transporters. Thus, unlike azoles, a major class of antifungals used against Candida, ABC transporter-mediated resistance is unlikely. Electron paramagnetic resonance (EPR)-spin trapping data suggested that the fungicidal light-induced action of these derivatives might depend on the production of superoxide anion. The highest generation rate of superoxide anion was observed for 1330H, 1610H, and 1611. Singlet oxygen production was also detected upon the irradiation of imidazoacridinone derivatives with UV laser light, with a low to moderate yield, depending on the type of compound. Thus, imidazoacridinone derivatives examined in the present study might act via mixed type I/type II photodynamic mechanism. The presented data indicate lack of direct correlation between the structures of studied imidazoacridinones, cell killing ability, and ROS production. However, we showed for the first time that for imidazoacridinones not only intracellular accumulation is necessary prerequisite of lethal photosensitization of C. albicans, but also localization within particular cellular structures

  9. Photodynamic Inactivation of Candida albicans with Imidazoacridinones: Influence of Irradiance, Photosensitizer Uptake and Reactive Oxygen Species Generation.

    PubMed

    Taraszkiewicz, Aleksandra; Szewczyk, Grzegorz; Sarna, Tadeusz; Bielawski, Krzysztof P; Nakonieczna, Joanna

    2015-01-01

    The increasing applicability of antifungal treatments, the limited range of available drug classes and the emergence of drug resistance in Candida spp. suggest the need for new treatment options. To explore the applicability of C. albicans photoinactivation, we examined nine structurally different imidazoacridinone derivatives as photosensitizing agents. The most effective derivatives showed a >10(4)-fold reduction of viable cell numbers. The fungicidal action of the three most active compounds was compared at different radiant powers (3.5 to 63 mW/cm2), and this analysis indicated that 7 mW/cm2 was the most efficient. The intracellular accumulation of these compounds in fungal cells correlated with the fungicidal activity of all 9 derivatives. The lack of effect of verapamil, an inhibitor targeting Candida ABC efflux pumps, suggests that these imidazoacridinones are not substrates for ABC transporters. Thus, unlike azoles, a major class of antifungals used against Candida, ABC transporter-mediated resistance is unlikely. Electron paramagnetic resonance (EPR)-spin trapping data suggested that the fungicidal light-induced action of these derivatives might depend on the production of superoxide anion. The highest generation rate of superoxide anion was observed for 1330H, 1610H, and 1611. Singlet oxygen production was also detected upon the irradiation of imidazoacridinone derivatives with UV laser light, with a low to moderate yield, depending on the type of compound. Thus, imidazoacridinone derivatives examined in the present study might act via mixed type I/type II photodynamic mechanism. The presented data indicate lack of direct correlation between the structures of studied imidazoacridinones, cell killing ability, and ROS production. However, we showed for the first time that for imidazoacridinones not only intracellular accumulation is necessary prerequisite of lethal photosensitization of C. albicans, but also localization within particular cellular

  10. Prospective evaluation of the chromogenic medium CandiSelect 4 for differentiation and presumptive identification of non-Candida albicans Candida species.

    PubMed

    Zhao, Liang; de Hoog, G Sybren; Cornelissen, Akke; Lyu, Qian; Mou, Lili; Liu, Taohua; Cao, Yu; Vatanshenassan, Mansoureh; Kang, Yingqian

    2016-02-01

    Rapid identification of pathogenic yeasts is a crucial step in timely and appropriate antifungal therapy. For diagnostics in the clinical laboratory, simplified alternatives to barcoding are needed. CandiSelect 4 (CS4) medium, a chromogenic medium for isolation of clinical yeasts, allows routine recognition of Candida albicans and presumptive identification of Candida tropicalis, Candida glabrata, and Candida krusei. We evaluated an extension of this method with 46 non-Candida albicans Candida (NCAC) and 7 Malassezia species. The medium supported growth of all species tested and a wide diversity of cultural types were observed. Colony colours were in violet, turquoise (including green and blue), or white tinges. Eight NCAC species produced violet pigmentation similar to that of C. albicans. Most NCAC species, including C. glabrata and C. tropicalis were distributed in the turquoise group. Malassezia species were invariably blue. PMID:26781374

  11. Candida albicans pancreatitis in a child with cystic fibrosis post lung transplantation.

    PubMed

    Hammer, Mark M; Zhang, Lingxin; Stoll, Janis M; Sheybani, Elizabeth F

    2016-04-01

    We present a case of Candida albicans infection of a previously intact pancreas in a child with cystic fibrosis status post lung transplantation. Although Candida superinfection in necrotizing pancreatitis is not uncommon, this is a unique case of Candida infection of non-necrotic pancreatic parenchyma. This case presented a diagnostic dilemma for radiologists because it appeared virtually identical to acute interstitial edematous pancreatitis on imaging. Ultimately, endoscopic US-based biopsy was pursued for diagnosis. Although difficult to treat and compounded by the immunocompromised status of the child, the pancreatic infection improved with antifungal therapy. PMID:26546567

  12. Altered hepatic clearance and killing of Candida albicans in the isolated perfused mouse liver model.

    PubMed Central

    Sawyer, R T; Horst, M N; Garner, R E; Hudson, J; Jenkins, P R; Richardson, A L

    1990-01-01

    The adherence of Candida albicans was studied in situ by using the perfused mouse liver model. After exhaustive washing, 10(6) C. albicans were infused into mouse livers. At the time of recovery, 62 +/- 5% (mean +/- standard error of the mean) of the infused C. albicans were recovered from the liver and 14 +/- 3% were recovered from the effluent for a total recovery of 76 +/- 4%. This indicates that 86 +/- 3% of the original inoculum was trapped by the liver and that 24 +/- 4% was killed within the liver. Chemical pretreatment of C. albicans with 8 M urea, 12 mM dithiothreitol, 2% beta-mercaptoethanol, 1% sodium dodecyl sulfate, 10% Triton X-100, or 3 M potassium chloride or enzyme pretreatment with alpha-mannosidase, alpha-chymotrypsin, subtilisin, beta-N-acetyl-glucosaminidase, pronase, trypsin, papain, or lipase did not alter adherence of C. albicans to hepatic tissue. By contrast, pepsin pretreatment significantly decreased hepatic trapping. Simultaneous perfusion with either 100 mg of C. albicans glycoprotein per liter or 100 mg of C. albicans mannan per liter also decreased trapping. Furthermore, both substances eluted previously trapped C. albicans from hepatic tissue. Chemical pretreatment with 8 M urea, 12 mM dithiothreitol, or 3 M KCI or enzymatic pretreatment with alpha-mannosidase, subtilisin, alpha-chymotrypsin, or papain increased killing of C. albicans three- to fivefold within hepatic tissue. The data suggest that mannose-containing structures on the surface of C. albicans, for example. mannans or glucomannoproteins, mediate adherence of C. albicans within the liver. Indirectly, chemical and enzymatic pretreatment renders C. albicans more susceptible to hepatic killing. PMID:2117571

  13. Candida albicans Shaving to Profile Human Serum Proteins on Hyphal Surface

    PubMed Central

    Marín, Elvira; Parra-Giraldo, Claudia M.; Hernández-Haro, Carolina; Hernáez, María L.; Nombela, César; Monteoliva, Lucía; Gil, Concha

    2015-01-01

    Candida albicans is a human opportunistic fungus and it is responsible for a wide variety of infections, either superficial or systemic. C. albicans is a polymorphic fungus and its ability to switch between yeast and hyphae is essential for its virulence. Once C. albicans obtains access to the human body, the host serum constitutes a complex environment of interaction with C. albicans cell surface in bloodstream. To draw a comprehensive picture of this relevant step in host-pathogen interaction during invasive candidiasis, we have optimized a gel-free shaving proteomic strategy to identify both, human serum proteins coating C. albicans cells and fungi surface proteins simultaneously. This approach was carried out with normal serum (NS) and heat inactivated serum (HIS). We identified 214 human and 372 C. albicans unique proteins. Proteins identified in C. albicans included 147 which were described as located at the cell surface and 52 that were described as immunogenic. Interestingly, among these C. albicans proteins, we identified 23 GPI-anchored proteins, Gpd2 and Pra1, which are involved in complement system evasion and 7 other proteins that are able to attach plasminogen to C. albicans surface (Adh1, Eno1, Fba1, Pgk1, Tdh3, Tef1, and Tsa1). Furthermore, 12 proteins identified at the C. albicans hyphae surface induced with 10% human serum were not detected in other hypha-induced conditions. The most abundant human proteins identified are involved in complement and coagulation pathways. Remarkably, with this strategy, all main proteins belonging to complement cascades were identified on the C. albicans surface. Moreover, we identified immunoglobulins, cytoskeletal proteins, metabolic proteins such as apolipoproteins and others. Additionally, we identified more inhibitors of complement and coagulation pathways, some of them serpin proteins (serine protease inhibitors), in HIS vs. NS. On the other hand, we detected a higher amount of C3 at the C. albicans surface in

  14. Hydrophobic properties of Candida spp. under the influence of selected essential oils.

    PubMed

    Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina; Pęczek, Marlena

    2015-01-01

    Processes of colonization of biotic and abiotic surfaces and biofilm formation depend inter alia on hydrophobic properties of Candida spp. The aim of this research was to determine the effect of tea tree, thyme and clove essential oils on hydrophobic properties of environmental and clinical Candida isolates. The relative cell surface hydrophobicity of strains tested was high, and ranged from 68.7% to 91.2%, with the highest value for a C. rugosa food-borne strain. The effectiveness of essential oils was diversified and depended on the type of essential oil, concentration and yeast strain. Statistically significant decrease of hydrophobicity indexes was observed after application of tea tree oil for C. krusei, clove oil for C. albicans reference strain, and all essential oils tested for C. rugosa. Only in the case of C. famata food-borne strain and C. albicans clinical isolate, solely used essential oils did not affect their hydrophobic properties. To determine the interactions of essential oils, their mixtures (1 MIC:1 MIC, 1 MIC:2 MIC and 2 MIC:1 MIC) were applied. Generally, essential oils used in combinations influenced yeast's hydrophobic properties much more than applied separately. The essential oils' mixtures reduced hydrophobicity of Candida yeasts in the range of 8.2 to 45.1%, depending on combination and strain. The interaction indexes of essential oils used in combinations predominantly indicate their additive effect. The application of tea tree, thyme and clove essential oils, especially in combinations, decreases hydrophobicity of the tested Candida isolates with implications of a probable advantageous limitation of their ability to colonize the food production industry environment. PMID:26601324

  15. Increased phenotypic switching in strains of Candida albicans associated with invasive infections.

    PubMed Central

    Jones, S; White, G; Hunter, P R

    1994-01-01

    This study reports the rates of phenotypic switching in strains of Candida albicans isolated from superficial and invasive infections. Of 19 invasive strains, 68% showed switching activity, often at very high rates, compared with only 28% of 40 strains isolated from superficial sites (P = 0.004). PMID:7852592

  16. Rapid and Accurate Identification of Candida albicans Isolates by Use of PNA FISHFlow▿

    PubMed Central

    Trnovsky, Jan; Merz, William; Della-Latta, Phyllis; Wu, Fann; Arendrup, Maiken Cavling; Stender, Henrik

    2008-01-01

    We developed the simple, rapid (1 h), and accurate PNA FISHFlow method for the identification of Candida albicans. The method exploits unique in solution in situ hybridization conditions under which the cells are simultaneously fixed and hybridized. This method facilitates the accurate identification of clinical yeast isolates using two scoring techniques: flow cytometry and fluorescence microscopy. PMID:18287325

  17. Host responses to Candida albicans: Th17 cells and mucosal candidiasis

    PubMed Central

    Conti, Heather R.; Gaffen, Sarah L.

    2010-01-01

    Candida albicans causes mucosal and disseminated candidiasis, which represent serious problems for the rapidly expanding immunocompromised population. Until recently, Th1-mediated immunity was thought to confer the primary protection, particularly for oral candidiasis. However, emerging data indicate that the newly-defined Th17 compartment appears to play the predominant role in mucosal candidiasis. PMID:20381638

  18. Cerebral macroabscess caused by Candida albicans in an immunocompetent patient: A diagnostic challenge

    PubMed Central

    Figueiredo, Sônia M.; Campolina, Sabrina; Rosa, Carlos A.; Gontijo, Marcus; Tirone, Thelma; Assunção, Claudia B.; Freire, Tarcísio F.A.; Christo, Paulo P.; Caligiorne, Rachel B.

    2014-01-01

    We describe the history of a 24-year-old immunocompetent man with an expansive lesion in the brainstem that, after many misdiagnoses, was found to be caused by a Candida albicans abscess. One year after surgery and 3 months of fluconazole treatment, the patient was asymptomatic and all image and laboratory tests were normal. PMID:24567895

  19. Kinetic Patterns of Candida albicans Germ Tube Antibody in Critically Ill Patients: Influence on Mortality▿

    PubMed Central

    Zaragoza, Rafael; Pemán, Javier; Quindós, Guillermo; Iruretagoyena, Jose R.; Cuétara, María S.; Ramírez, Paula; Gómez, Maria D.; Camarena, Juan J.; Viudes, Angel; Pontón, José

    2009-01-01

    The influence of kinetic patterns of Candida albicans germ tube antibodies (CAGTA) on mortality was analyzed in six intensive care units. Statistically significant lower mortality rates were found in patients with patterns of increasing CAGTA titers who had been treated with antifungal agents. Thus, antifungal treatment should be considered when CAGTA titers are increasing in critically ill patients. PMID:19675223

  20. Effect of surface treatments of porcelain on adhesion of Candida albicans.

    PubMed

    Lawaf, Shirin; Azizi, Arash; Farzad, Azin; Adimi, Parvaneh

    2016-01-01

    Surface treatment of porcelain is required to minimize the adhesion of microorganisms to surfaces of the restoration. This study sought to assess the effects of 3 different porcelain surface treatments on adhesion of Candida albicans. This in vitro experimental study was conducted on 60 porcelain disks (10 × 3 mm) randomly divided into 4 groups of 15. The nonglazed group received no surface treatment; specimens in the other 3 groups were glazed in the furnace, overglazed with liquid glaze, or polished using a polishing kit. The specimens were washed, sterilized, and separately incubated with 350 µL of Candida albicans suspension for 24 hours. Specimens were then rinsed for 20 seconds and shaken in 1 mL of saline solution for 1 minute, and 20 µL of this suspension was cultured in a plate and incubated at 37°C for 48 hours. Candida albicans colonies were counted to assess the number of microorganisms adhering to each disk. Data were analyzed with the Kruskal-Wallis test. Statistically significant differences were found among the 4 groups in terms of C albicans adherence (P = 0.001). The nonglazed porcelain had the highest and the overglazed porcelain had the lowest mean adherence value. No statistically significant difference was noted between glazed and polished specimens. Based on the obtained results, overglazing resulted in the least adhesion of C albicans, and polishing provided a surface as smooth as a glazed surface. PMID:27367639

  1. 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.

  2. Evaluation of the new chromogenic medium Candida ID 2 for isolation and identification of Candida albicans and other medically important Candida species.

    PubMed

    Eraso, Elena; Moragues, María D; Villar-Vidal, María; Sahand, Ismail H; González-Gómez, Nagore; Pontón, José; Quindós, Guillermo

    2006-09-01

    The usefulness of Candida ID 2 (CAID2) reformulated medium (bioMérieux, France) has been compared with that of the former Candida ID (CAID; bioMérieux), Albicans ID 2 (ALB2; bioMérieux), and CHROMagar Candida (CAC; Chromagar, France) chromogenic media for the isolation and presumptive identification of clinically relevant yeasts. Three hundred forty-five stock strains from culture collections, and 103 fresh isolates from different clinical specimens were evaluated. CAID2 permitted differentiation based on colony color between Candida albicans (cobalt blue; sensitivity, 91.7%; specificity, 97.2%) and Candida dubliniensis (turquoise blue; sensitivity, 97.9%; specificity, 96.6%). Candida tropicalis gave distinguishable pink-bluish colonies in 97.4% of the strains in CAID2 (sensitivity, 97.4%; specificity, 100%); the same proportion was reached in CAC, where colonies were blue-gray (sensitivity, 97.4%; specificity, 98.7%). CAC and CAID2 showed 100% sensitivity values for the identification of Candida krusei. However, with CAID2, experience is required to differentiate the downy aspect of the white colonies of C. krusei from other white-colony-forming species. The new CAID2 medium is a good candidate to replace CAID and ALB2, and it compares well to CAC for culture and presumptive identification of clinically relevant Candida species. CAID2 showed better results than CAC in some aspects, such as quicker growth and color development of colonies from clinical specimens, detection of mixed cultures, and presumptive differentiation between C. albicans and C. dubliniensis. PMID:16954270

  3. Evaluation of Candida albicans formation on feldspathic porcelain subjected to four surface treatment methods.

    PubMed

    Karayazgan, Banu; Atay, Arzu; Saracli, Mehmet Ali; Gunay, Yumushan

    2010-03-01

    Candida albicans, known for its adhesion on prosthetic materials and oral tissues, is the most frequently encountered fungal infection in dentistry. The aim of this study was to evaluate the effects of four different surface treatment methods and immersion in artificial saliva on the surface roughness of and candida adhesion on dental porcelains. The four surface treatment methods were namely: natural glaze, overglaze, dual ion exchange, and polishing. Surface roughness of porcelain was evaluated using a surface profilometer and by SEM. Candida adhesion was examined by culturing two Candida strains on porcelain specimens followed by a colorimetric method using XTT/Coenzyme Q0. It became evident that Candida adhesion was found more in the specimens treated with natural glaze and polishing. Further, by the visual inspection of SEM images and comparison of surface roughness, polished and natural-glazed specimens showed rougher surface characteristics than overglazed and dual-ion-exchanged specimens. PMID:20379024

  4. IL-33 Priming Enhances Peritoneal Macrophage Activity in Response to Candida albicans.

    PubMed

    Tran, Vuvi G; Cho, Hong R; Kwon, Byungsuk

    2014-08-01

    IL-33 is a member of the IL-1 cytokine family and plays a role in the host defense against bacteria, viruses, and fungi. In this study, we investigated the function of IL-33 and its receptor in in vitro macrophage responses to Candida albicans. Our results demonstrate that pre-sensitization of isolated peritoneal macrophages with IL-33 enhanced their pro-inflammatory cytokine production and phagocytic activity in response to C. albicans. These macrophage activities were entirely dependent on the ST2-MyD88 signaling pathway. In addition, pre-sensitization with IL-33 also increased ROS production and the subsequent killing ability of macrophages following C. albicans challenge. These results indicate that IL-33 may increase anti-fungal activity against Candida through macrophage-mediated resistance mechanisms. PMID:25177252

  5. Antifungal Effect of Zataria multiflora Essence on Experimentally Contaminated Acryl Resin Plates With Candida albicans

    PubMed Central

    Jafari, Abbas Ali; Falah Tafti, Abbas; Hoseiny, Seyed Mehdi; Kazemi, Abdolhossein

    2015-01-01

    Background: Adherence and colonization of Candida species particularly C. albicans on denture surfaces, forms a microbial biofilm, which may result denture stomatitis in complete denture users. Objectives: The purpose of the present study was to evaluate the antifungal effect Zataria multiflora essence in removing of Candida albicans biofilms on experimentally contaminated resin acryl plates. Materials and Methods: In the present experimental study, 160 resin acrylic plates (10 × 10 × 1 mm) were contaminated by immersion in 1 × 103 C. albicans suspension for 24 hours to prepare experimental Candida biofilms. The total number of Candida cells, which adhered to 20 randomly selected acryl resin plates was determined as the Candia load before cleaning. The remaining 140 plates were divided to seven groups of 20 and immersed in five concentrations of Zataria multiflora essence from 50 to 3.125 mg/mL as test, 100000 IU nystatin as the positive and sterile physiologic serum as the negative control. The remaining Candida cells on each acryl plate were also enumerated and data were analyzed using the SPSS 16 software with Kruskal-Wallis and Wilcoxon tests. Results: Zataria essence at concentrations of 50 and 25 mg/mL removed 100% of attached Candida cells similar to nystatine (MFC), while weaker Zataria essence solutions cleaned 88%, 60.5% and 44.7% of attached Candida cells. Kruskal-wallis test showed a statistically significant difference between all test groups (P = 0.0001). In this study 12.5 mg/mL concentration of Zataria multiflora was considered as the minimum inhibitory concentration (MIC90). Conclusions: Zataria essence, at concentrations of 50 and 25 mg/mL, effectively removed Candida cells that had adhered to the denture surface, similar to the level of removal observed for 100000 IU nystatin. PMID:25763273

  6. Dynamic Transcript Profiling of Candida albicans Infection in Zebrafish: A Pathogen-Host Interaction Study

    PubMed Central

    Liu, Fu-Chen; Hsu, Po-Chen; Chen, Hsueh-Fen; Peng, Shih-Chi; Chuang, Yung-Jen; Lan, Chung-Yu; Hsieh, Wen-Ping; Wong, David Shan Hill

    2013-01-01

    Candida albicans is responsible for a number of life-threatening infections and causes considerable morbidity and mortality in immunocompromised patients. Previous studies of C. albicans pathogenesis have suggested several steps must occur before virulent infection, including early adhesion, invasion, and late tissue damage. However, the mechanism that triggers C. albicans transformation from yeast to hyphae form during infection has yet to be fully elucidated. This study used a systems biology approach to investigate C. albicans infection in zebrafish. The surviving fish were sampled at different post-infection time points to obtain time-lapsed, genome-wide transcriptomic data from both organisms, which were accompanied with in sync histological analyses. Principal component analysis (PCA) was used to analyze the dynamic gene expression profiles of significant variations in both C. albicans and zebrafish. The results categorized C. albicans infection into three progressing phases: adhesion, invasion, and damage. Such findings were highly supported by the corresponding histological analysis. Furthermore, the dynamic interspecies transcript profiling revealed that C. albicans activated its filamentous formation during invasion and the iron scavenging functions during the damage phases, whereas zebrafish ceased its iron homeostasis function following massive hemorrhage during the later stages of infection. Most of the immune related genes were expressed as the infection progressed from invasion to the damage phase. Such global, inter-species evidence of virulence-immune and iron competition dynamics during C. albicans infection could be crucial in understanding control fungal pathogenesis. PMID:24019870

  7. Plant-derived decapeptide OSIP108 interferes with Candida albicans biofilm formation without affecting cell viability.

    PubMed

    Delattin, Nicolas; De Brucker, Katrijn; Craik, David J; Cheneval, Olivier; Fröhlich, Mirjam; Veber, Matija; Girandon, Lenart; Davis, Talya R; Weeks, Anne E; Kumamoto, Carol A; Cos, Paul; Coenye, Tom; De Coninck, Barbara; Cammue, Bruno P A; Thevissen, Karin

    2014-05-01

    We previously identified a decapeptide from the model plant Arabidopsis thaliana, OSIP108, which is induced upon fungal pathogen infection. In this study, we demonstrated that OSIP108 interferes with biofilm formation of the fungal pathogen Candida albicans without affecting the viability or growth of C. albicans cells. OSIP108 displayed no cytotoxicity against various human cell lines. Furthermore, OSIP108 enhanced the activity of the antifungal agents amphotericin B and caspofungin in vitro and in vivo in a Caenorhabditis elegans-C. albicans biofilm infection model. These data point to the potential use of OSIP108 in combination therapy with conventional antifungal agents. In a first attempt to unravel its mode of action, we screened a library of 137 homozygous C. albicans mutants, affected in genes encoding cell wall proteins or transcription factors important for biofilm formation, for altered OSIP108 sensitivity. We identified 9 OSIP108-tolerant C. albicans mutants that were defective in either components important for cell wall integrity or the yeast-to-hypha transition. In line with these findings, we demonstrated that OSIP108 activates the C. albicans cell wall integrity pathway and that its antibiofilm activity can be blocked by compounds inhibiting the yeast-to-hypha transition. Furthermore, we found that OSIP108 is predominantly localized at the C. albicans cell surface. These data point to interference of OSIP108 with cell wall-related processes of C. albicans, resulting in impaired biofilm formation. PMID:24566179

  8. Activation of HIF-1α and LL-37 by commensal bacteria inhibits Candida albicans colonization

    PubMed Central

    Fan, Di; Coughlin, Laura A.; Neubauer, Megan M.; Kim, Jiwoong; Kim, Minsoo; Zhan, Xiaowei; Simms-Waldrip, Tiffany R.; Xie, Yang; Hooper, Lora V.; Koh, Andrew Y.

    2015-01-01

    Candida albicans colonization is required for invasive disease1-3. Unlike humans, adult mice with mature intact gut microbiota are resistant to C. albicans gastrointestinal (GI) colonization2,4. But the factors that promote C. albicans colonization resistance are unknown. Here we demonstrate that commensal anaerobic bacteria – specifically Clostridial Firmicutes (Clusters IV and XIVa) and Bacteroidetes – are critical for maintaining C. albicans colonization resistance in mice. Using Bacteroides thetaiotamicron as a model organism, we find that HIF-1α, a transcription factor important for activating innate immune effectors, and the antimicrobial peptide LL37-CRAMP are key determinants of C. albicans colonization resistance. While antibiotic treatment enables C. albicans colonization, pharmacologic activation of colonic Hif1a induces CRAMP expression and results in a significant reduction of C. albicans GI colonization and a 50% decrease in mortality from invasive disease. In the setting of antibiotics, Hif1a and Cramp are required for B. thetaiotamicron-induced protection against CA colonization of the gut. Thus, C. albicans GI colonization modulation by activation of gut mucosal immune effectors may represent a novel therapeutic approach for preventing invasive fungal disease in humans. PMID:26053625

  9. CHARACTERIZATION OF THE PYROGENICITY OF CANDIDA ALBICANS, SACCHAROMYCES CEREVISIAE, AND CRYPTOCOCCUS NEOFORMANS.

    PubMed

    KOBAYASHI, G S; FRIEDMAN, L

    1964-09-01

    Kobayashi, George S. (Tulane University, New Orleans, La.), and Lorraine Friedman. Characterization of the pyrogenicity of Candida albicans, Saccharomyces cerevisiae, and Cryptococcus neoformans. J. Bacteriol. 88:660-666. 1964.-The intravenous injection into rabbits of 10(9) yeast cells of Candida albicans, Saccharomyces cerevisiae, or Cryptococcus neoformans (both slightly and heavily encapsulated forms) induced a febrile response indistinguishable from that elicited by gram-negative bacterial endotoxin. There was a brisk rise in body temperature which began as early as 30 min after injection, peaked once or twice, and then returned to normal after about 10 hr. With viable C. albicans, the febrile response did not return to normal but remained elevated for several days and terminated at death of the animal. Of three extraction procedures employed in attempts to isolate the endotoxin-like pyrogenically active substances from C. albicans, only one, the phenol extraction method, was successful. Pyrogenic substances were more easily extractable from S. cerevisiae, but extracted cells of both species were still highly pyrogenic. It was concluded that the particulate nature of the yeast cell did not contribute to the induction of fever, for latex particles of a similar size were nonpyrogenic. Viable or heat-killed C. albicans, phenol extract of C. albicans, zymosan, and polystyrene latex particles all failed to induce in rabbits increased dermal reactivity to epinephrine. PMID:14208504

  10. Candida albicans chronic colonisation in cystic fibrosis may be associated with inhaled antibiotics.

    PubMed

    Noni, Maria; Katelari, Anna; Kaditis, Athanasios; Theochari, Ioanna; Lympari, Ioulia; Alexandrou-Athanassoulis, Helen; Doudounakis, Stavros-Eleftherios; Dimopoulos, George

    2015-07-01

    Candida albicans is increasingly recognised as a coloniser of the respiratory tract in cystic fibrosis (CF) patients. Yet, the potential role, if any, of the micro-organism in the progress of the disease remains unclear. In this study, we investigated the association between inhaled antibiotics and C. albicans chronic colonisation in patients with CF. A cohort of 121 CF patients born from 1988 to 1996 was, respectively, studied. The medical records of each patient were reviewed from the first time they attended the CF Centre until the occurrence of C. albicans chronic colonisation or their last visit for the year 2010. Chronic colonisation was defined as the presence of C. albicans in more than 50% of cultures in a given year. A number of possible confounders were included in the multivariate logistic regression analysis to identify an independent association between inhaled antibiotics and C. albicans chronic colonisation. Fifty-four (44.6%) of the 121 patients enrolled in the study developed chronic colonisation by the micro-organism. Multivariate logistic regression analysis determined the independent effect of inhaled antibiotic treatment on the odds of chronic colonisation (OR 1.112, 95% CI [1.007-1.229], P = 0.036). Candida albicans chronic colonisation may be associated with the duration of inhaled antibiotic treatment. PMID:26058475

  11. Time-course proteomic profile of Candida albicans during adaptation to a fetal serum.

    PubMed

    Aoki, Wataru; Ueda, Tomomi; Tatsukami, Yohei; Kitahara, Nao; Morisaka, Hironobu; Kuroda, Kouichi; Ueda, Mitsuyoshi

    2013-02-01

    Candida albicans is a commensal organism; however, it causes fatal diseases if the host immunity is compromised. The mortality rate is very high due to the lack of effective treatment, leading to ceaseless demand for novel pharmaceuticals. In this study, time-course proteomics of C. albicans during adaptation to fetal bovine serum (FBS) was described. Time-course proteomics is a promising way to understand the exact process of going adaptation in dynamically changing environments. Candida albicans was cultivated in yeast nitrogen base (YNB) ± FBS media, and we identified 1418 proteins in the endpoint samples incubated for 0 or 60 min by a LC-MS/MS system with a long monolithic silica capillary column. Next, we carried out time-course proteomics of the YNB + FBS samples to identify top-priority proteins for adaption to FBS. We identified 16 proteins as nascent/newly synthesized proteins, and they were recognized as candidates of important virulent factors. Gene ontology analysis revealed that transport-related proteins were enriched in the 16 proteins, indicating that C. albicans probably put priority in time on the acquisition of essential elements. Time-course proteomics of C. albicans revealed the order of priority to adapt to FBS. Depicting time-course dynamics will lead to profound understandings of virulence of C. albicans. PMID:23620121

  12. Inhibition of Candida albicans biofilm formation and modulation of gene expression by probiotic cells and supernatant.

    PubMed

    James, K M; MacDonald, K W; Chanyi, R M; Cadieux, P A; Burton, J P

    2016-04-01

    Oral candidiasis is a disease caused by opportunistic species of Candida that normally reside on human mucosal surfaces. The transition of Candida from budding yeast to filamentous hyphae allows for covalent attachment to oral epithelial cells, followed by biofilm formation, invasion and tissue damage. In this study, combinations of Lactobacillus plantarum SD5870, Lactobacillus helveticus CBS N116411 and Streptococcus salivarius DSM 14685 were assessed for their ability to inhibit the formation of and disrupt Candida albicans biofilms. Co-incubation with probiotic supernatants under hyphae-inducing conditions reduced C. albicans biofilm formation by >75 % in all treatment groups. Likewise, combinations of live probiotics reduced biofilm formation of C. albicans by >67 %. When live probiotics or their supernatants were overlaid on preformed C. albicans biofilms, biofilm size was reduced by >63 and >65 % respectively. Quantitative real-time PCR results indicated that the combined supernatants of SD5870 and CBS N116411 significantly reduced the expression of several C. albicans genes involved in the yeast-hyphae transition: ALS3 (adhesin/invasin) by 70 % (P < 0.0001), EFG1 (hyphae-specific gene activator) by 47 % (P = 0.0061), SAP5 (secreted protease) by 49 % (P < 0.0001) and HWP1 (hyphal wall protein critical to biofilm formation) by >99 % (P < 0.0001). These findings suggest the combination of L. plantarum SD5870, L. helveticus CBS N116411 and S. salivarius DSM 14685 is effective at both preventing the formation of and removing preformed C. albicans biofilms. Our novel results point to the downregulation of several Candida genes critical to the yeast-hyphae transition, biofilm formation, tissue invasion and cellular damage. PMID:26847045

  13. The proteolytic potential of Candida albicans in human saliva supplemented with glucose.

    PubMed

    Samaranayake, L P; Hughes, A; MacFarlane, T W

    1984-02-01

    The production of proteases by Candida albicans in batch cultures of human saliva supplemented with glucose was investigated with two clinical strains of Candida and both individual and pooled samples of whole saliva from volunteers. Salivary proteolysis during a 48-h period was estimated by biochemical and isoelectric focusing techniques. Candidal growth in saliva was associated with acid production and salivary proteolysis and there was a highly significant positive correlation between these two activities. Neither candidal growth nor proteolysis was observed in glucose-free control samples and with one strain of Candida cultured in the saliva of one individual. Isotachophoretic analysis of culture liquor showed a significant increase in acetate and pyruvate ions. The oral cavity provides niches that have a low pH and are periodically supplemented with dietary carbohydrates. The acidic proteases of C. albicans may play a role in the pathogenesis of oral candidoses. PMID:6363704

  14. The expression of genes involved in the ergosterol biosynthesis pathway in Candida albicans and Candida dubliniensis biofilms exposed to fluconazole.

    PubMed

    Borecká-Melkusová, Silvia; Moran, Gary P; Sullivan, Derek J; Kucharíková, Sona; Chorvát, Dusan; Bujdáková, Helena

    2009-03-01

    The expression of the ERG1, ERG3, ERG7, ERG9, ERG11 and ERG25 genes in response to incubation with fluconazole and biofilm formation was investigated using reverse-transcription PCR and real-time PCR in Candida albicans and Candida dubliniensis clinical isolates. The viability of biofilm was measured using an 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay and confocal scanning laser microscopy (CSLM). Expression of the ERG11 gene was found to be low or moderate and it was regulated by fluconazole addition more so than by biofilm formation. Very low or non-detectable expression of ERG1, ERG7 and ERG25 genes was detected in C. albicans. The expression of the ERG9 increased in the presence of fluconazole in some isolates. Following incubation with fluconazole, formation of biofilm by C. dubliniensis was coupled with up-regulation of the ERG3 and ERG25 genes as have been observed previously in C. albicans. Planktonic cells of both Candida species released from biofilm displayed similar resistance mechanisms to fluconazole like attached cells. The XTT reduction assay and CSLM revealed that although incubation with fluconazole decreased the biofilm thickness, these were still comprised metabolically active cells able to disseminate and produce biofilm. Our data indicate that biofilm represents a highly adapted community reflecting the individuality of clinical isolates. PMID:18627475

  15. Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

    PubMed Central

    Baumgartner, C; Freydiere, A M; Gille, Y

    1996-01-01

    Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates were, respectively, 37.0 and 6.0% after 24 h of incubation and 93.6 and 92.2% after 72 h of incubation, with specificities of 99.8 and 100%. Furthermore, CHROMagar Candida plates identified 13 of 14 Candida tropicalis and 9 of 12 Candida krusei strains after 48 h of incubation. PMID:8789038

  16. Antimicrobial blue light inactivation of Candida albicans: In vitro and in vivo studies.

    PubMed

    Zhang, Yunsong; Zhu, Yingbo; Chen, Jia; Wang, Yucheng; Sherwood, Margaret E; Murray, Clinton K; Vrahas, Mark S; Hooper, David C; Hamblin, Michael R; Dai, Tianhong

    2016-07-01

    Fungal infections are a common cause of morbidity, mortality and cost in critical care populations. The increasing emergence of antimicrobial resistance necessitates the development of new therapeutic approaches for fungal infections. In the present study, we investigated the effectiveness of an innovative approach, antimicrobial blue light (aBL), for inactivation of Candida albicans in vitro and in infected mouse burns. A bioluminescent strain of C. albicans was used. The susceptibilities to aBL (415 nm) were compared between C. albicans and human keratinocytes. The potential development of aBL resistance by C. albicans was investigated via 10 serial passages of C. albicans on aBL exposure. For the animal study, a mouse model of thermal burn infected with the bioluminescent C. albicans strain was used. aBL was delivered to mouse burns approximately 12 h after fungal inoculation. Bioluminescence imaging was performed to monitor in real time the extent of infection in mice. The results obtained from the studies demonstrated that C. albicans was approximately 42-fold more susceptible to aBL than human keratinocytes. Serial passaging of C. albicans on aBL exposure implied a tendency of reduced aBL susceptibility of C. albicans with increasing numbers of passages; however, no statistically significant difference was observed in the post-aBL survival rate of C. albicans between the first and the last passage (P>0.05). A single exposure of 432 J/cm(2) aBL reduced the fungal burden in infected mouse burns by 1.75-log10 (P=0.015). Taken together, our findings suggest aBL is a potential therapeutic for C. albicans infections. PMID:26909654

  17. Terpenoids inhibit Candida albicans growth by affecting membrane integrity and arrest of cell cycle.

    PubMed

    Zore, Gajanan B; Thakre, Archana D; Jadhav, Sitaram; Karuppayil, S Mohan

    2011-10-15

    Anti-Candida potential of six terpenoids were evaluated in this study against various isolates of Candida albicans (n=39) and non-C. albicans (n=9) that are differentially susceptible to fluconazole. All the six terpenoids tested, showed excellent activity and were equally effective against isolates of Candida sps., tested in this study. Linalool and citral were the most effective ones, inhibiting all the isolates at ≤0.064% (v/v). Five among the six terpenoids tested were fungicidal. Time dependent kill curve assay showed that MFCs of linalool and eugenol were highly toxic to C. albicans, killing 99.9% inoculum within seven min of exposure, while that of citronellal, linalyl acetate and citral required 15min, 1h and 2h, respectively. FIC index values (Linalool - 0.140, benzyl benzoate - 0.156, eugenol - 0.265, citral - 0.281 and 0.312 for linalyl acetate and citronellal) and isobologram obtained by checker board assay showed that all the six terpenoids tested exhibit excellent synergistic activity with fluconazole against a fluconazole resistant strain of C. albicans. Terpenoids tested arrested C. albicans cells at different phases of the cell cycle i.e. linalool and LA at G1, citral and citronellal at S phase and benzyl benzoate at G2-M phase and induced apoptosis. Linalool, citral, citronellal and benzyl benzoate caused more than 50% inhibition of germ tube induction at 0.008%, while eugenol and LA required 0.032 and 0.016% (v/v) concentrations, respectively. MICs of all the terpenoids for the C. albicans growth were non toxic to HeLa cells. Terpenoids tested exhibited excellent activity against C. albicans yeast and hyphal form growth at the concentrations that are non toxic to HeLa cells. Terpenoids tested in this study may find use in antifungal chemotherapy, not only as antifungal agents but also as synergistic agents along with conventional drugs like fluconazole. PMID:21596542

  18. Control of Candida albicans metabolism and biofilm formation by Pseudomonas aeruginosa phenazines.

    PubMed

    Morales, Diana K; Grahl, Nora; Okegbe, Chinweike; Dietrich, Lars E P; Jacobs, Nicholas J; Hogan, Deborah A

    2013-01-01

    Candida albicans has developmental programs that govern transitions between yeast and filamentous morphologies and between unattached and biofilm lifestyles. Here, we report that filamentation, intercellular adherence, and biofilm development were inhibited during interactions between Candida albicans and Pseudomonas aeruginosa through the action of P. aeruginosa-produced phenazines. While phenazines are toxic to C. albicans at millimolar concentrations, we found that lower concentrations of any of three different phenazines (pyocyanin, phenazine methosulfate, and phenazine-1-carboxylate) allowed growth but affected the development of C. albicans wrinkled colony biofilms and inhibited the fungal yeast-to-filament transition. Phenazines impaired C. albicans growth on nonfermentable carbon sources and led to increased production of fermentation products (ethanol, glycerol, and acetate) in glucose-containing medium, leading us to propose that phenazines specifically inhibited respiration. Methylene blue, another inhibitor of respiration, also prevented the formation of structured colony biofilms. The inhibition of filamentation and colony wrinkling was not solely due to lowered extracellular pH induced by fermentation. Compared to smooth, unstructured colonies, wrinkled colony biofilms had higher oxygen concentrations within the colony, and wrinkled regions of these colonies had higher levels of respiration. Together, our data suggest that the structure of the fungal biofilm promotes access to oxygen and enhances respiratory metabolism and that the perturbation of respiration by bacterial molecules such as phenazines or compounds with similar activities disrupts these pathways. These findings may suggest new ways to limit fungal biofilms in the context of disease. IMPORTANCE Many of the infections caused by Candida albicans, a major human opportunistic fungal pathogen, involve both morphological transitions and the formation of surface-associated biofilms. Through the

  19. Chemical composition and antifungal potential of Brazilian propolis against Candida spp.

    PubMed

    Freires, I A; Queiroz, V C P P; Furletti, V F; Ikegaki, M; de Alencar, S M; Duarte, M C T; Rosalen, P L

    2016-06-01

    Propolis is known to have biological properties against numerous microorganisms of clinical interest. This study aimed to determine the chemical composition and antifungal activity of Brazilian propolis (types 3 and 13) against Candida spp. and their effects on the morphology of preformed and mature Candida biofilms. Samples of propolis (3 and 13) collected by Apis mellifera honeybees were obtained from different regions in Brazil. Ethanolic extracts of propolis (EEP) were prepared, fractionated and submitted to chemical analysis by GC/MS. The extracts and their hexane, dichloromethane and ethyl acetate fractions were tested for their ability to inhibit Candida spp. (C. albicans, C. dubliniensis, C. glabrata, C. kruzei, C. tropicalis and C. parapsilosis) by determination of the minimum inhibitory and fungicidal concentrations (MIC/MFC). Additionally, their effects on morphology of preformed and mature biofilms were observed by scanning electron microscopy. The phenolic compounds p-coumaric acid, caffeic acid phenethyl ester (CAPE), kaempferol and quercetin were identified in the EEP-3 and its bioactive dichloromethane fraction; and isoflavonoids such as medicarpin, vestitol and formononetin were found in the EEP-13, and triterpenes in its bioactive hexane fraction. The EEP-3 and EEP-13 and their bioactive fractions showed MIC values ranging from 0.2 to 125μg/mL and MFC values between 125 and 500μg/mL. The EEP and fractions were predominantly fungistatic agents. All extracts and fractions disrupted biofilm structures at 500μg/mL and amorphous areas with cell damage were clearly observed in preformed and mature biofilms. Propolis types 3 and 13 have strong anti-Candida activity and should be considered as promising candidates to treat oral and systemic candidiasis. PMID:26916845

  20. Impact of oxidative and osmotic stresses on Candida albicans biofilm formation.

    PubMed

    Pemmaraju, Suma C; Padmapriya, Kumar; Pruthi, Parul A; Prasad, R; Pruthi, Vikas

    2016-09-01

    Candida albicans possesses an ability to grow under different host-driven stress conditions by developing robust protective mechanisms. In this investigation the focus was on the impact of osmotic (2M NaCl) and oxidative (5 mM H2O2) stress conditions during C. albicans biofilm formation. Oxidative stress enhanced extracellular DNA secretion into the biofilm matrix, increased the chitin level, and reduced virulence factors, namely phospholipase and proteinase activity, while osmotic stress mainly increased extracellular proteinase and decreased phospholipase activity. Fourier transform infrared and nuclear magnetic resonance spectroscopy analysis of mannan isolated from the C. albicans biofilm cell wall revealed a decrease in mannan content and reduced β-linked mannose moieties under stress conditions. The results demonstrate that C. albicans adapts to oxidative and osmotic stress conditions by inducing biofilm formation with a rich exopolymeric matrix, modulating virulence factors as well as the cell wall composition for its survival in different host niches. PMID:27472386

  1. Increase of mouse resistance to Candida albicans infection by thymosin alpha 1.

    PubMed Central

    Bistoni, F; Marconi, P; Frati, L; Bonmassar, E; Garaci, E

    1982-01-01

    Studies were carried out to assess the ability of thymosin alpha 1 to prolong the survival of mice challenged with Candida albicans. Two- to four-month-old mice were treated with graded doses of thymosin alpha 1 before, after, or before and after intravenous challenge with C. albicans. Significant resistance ot lethal infection was afforded by 100 micrograms of thymosin alpha 1 per kg given before or before and after challenge, whereas no protection was found in mice treated with thymosin alpha 1 administered at any dose level after inoculation. Pretreatment with thymosin alpha 1 also prevented the increased susceptibility to C. albicans infection of mice pretreated with cyclophosphamide on day -6. The results showed that thymosin alpha 1 was capable of protecting untreated or cyclophosphamide-pretreated mice from C. albicans infection at an optimal dose and schedule of administration. PMID:7085074

  2. Correlation between virulence of Candida albicans mutants in mice and Galleria mellonella larvae.

    PubMed

    Brennan, Marc; Thomas, David Y; Whiteway, Malcolm; Kavanagh, Kevin

    2002-10-11

    Candida albicans is a dimorphic human pathogen in which the yeast to hyphal switch may be an important factor in virulence in mammals. This pathogen has recently been shown to also kill insects such as the Greater Wax Moth Galleria mellonella when injected into the haemocoel of the insect larvae. We have investigated the effect of previously characterised C. albicans mutations that influence the yeast to hyphal transition on virulence in G. mellonella larvae. There is a good correlation between the virulence of these mutants in the insect host and the virulence measured through systemic infection of mice. Although the predominant cellular species detected in G. mellonella infections is the yeast form of C. albicans, mutations that influence the hyphal transition also reduce pathogenicity in the insect. The correlation with virulence measured in the mouse infection system suggests that Galleria may provide a convenient and inexpensive model for the in vivo screening of mutants of C. albicans. PMID:12381467

  3. DNA content, kinetic complexity, and the ploidy question in Candida albicans

    SciTech Connect

    Riggsby, W.S.; Torres-Bauza, L.J.; Wills, J.W.; Townes, T.M.

    1982-07-01

    Candida albicans is a dimorphic fungus that is pathogenic for humans. No sexual cycle has been reported for this fungus, and earlier reports have differed on whether typical strains of C. albicans are haploid or diploid. Previous estimates of the DNA content of C. albicans varied by one order of magnitude. The authors used three independent methods to measure the kinetic complexity of the single-copy DNA from a typical strain of C. albicans (strain H317) to determine the DNA content per haploid genote; they obtained values of 15 and 20 fg per cell by using S1 nuclease and hydroxyapatite assays, respectively. Optical assays for DNA reassociation kinetics, although not definitive in themselves, yielded values in this range. Chemical measurements of the DNA content of several typical strains, including strain H317, yielded values clustered about a mean of 37 fg per cell. They concluded that these strains are diploid.

  4. Influence of tumour condition on the macrophage activity in Candida albicans infection.

    PubMed

    Venturini, J; de Camargo, M R; Félix, M C; Vilani-Moreno, F R; de Arruda, M S P

    2009-07-01

    To better understand the interactions between opportunistic fungi and their hosts, we investigated hydrogen peroxide (H2O2), nitric oxide and TNF-alpha production by peritoneal macrophages from Ehrlich tumour-bearing mice (TBM) during microbial infections. For this purpose, TBM at days 7, 14 and 21 of tumour progression were inoculated intraperitoneally with C. albicans and evaluated after 24 and 72 h. We observed that TBM showed significant increases in H2O2, TNF-alpha levels and fungal clearance at day 7 after C. albicans infection. However, as the tumour advanced, there was a progressive decline in the release of H2O2 and TNF-alpha that was paired with the dissemination of C. albicans. These results demonstrate that protective macrophage activities against Candida albicans are limited to the initial stages of tumour growth; continued solid tumour growth weakened the macrophage response and as a consequence, weakened the host's susceptibility to opportunistic infections. PMID:19522762

  5. Potent antifungal activity of extracts and pure compound isolated from pomegranate peels and synergism with fluconazole against Candida albicans.

    PubMed

    Endo, Eliana Harue; Cortez, Diógenes Aparício Garcia; Ueda-Nakamura, Tânia; Nakamura, Celso Vataru; Dias Filho, Benedito Prado

    2010-09-01

    Activity-guided repeated fractionation of crude hydro alcoholic extract prepared from the fruit peel of Punica granatum on a silica-gel column yielded a compound that exhibited strong antifungal activity against Candida spp. Based on spectral analyses, the compound was identified as punicalagin. Punicalagin showed strong activity against Candida albicans and Candida parapsilosis, with MICs of 3.9 and 1.9 microg/ml, respectively. The combination of punicalagin and fluconazole showed a synergistic interaction. MIC for fluconazole decreased twofold when combined with the extract. The FIC index was 0.25. The synergism observed in disk-diffusion and checkerboard assays was confirmed in time-kill curves. The effect of punicalagin on the morphology and ultrastructure in treated yeast cells was examined by scanning and transmission electron microscopy. An irregular budding pattern and pseudohyphae were seen in treated yeasts. By transmission electron microscopy, treated cells showed a thickened cell wall, changes in the space between cell wall and the plasma membrane, vacuoles, and a reduction in cytoplasmic content. Since the punicalagin concentration effective in vitro is achievable in vivo, the combination of this agent with fluconazole represents an attractive prospect for the development of new management strategies for candidiasis, and should be investigated further in in vivo models. PMID:20541606

  6. Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder.

    PubMed

    Severance, Emily G; Gressitt, Kristin L; Stallings, Catherine R; Katsafanas, Emily; Schweinfurth, Lucy A; Savage, Christina L; Adamos, Maria B; Sweeney, Kevin M; Origoni, Andrea E; Khushalani, Sunil; Leweke, F Markus; Dickerson, Faith B; Yolken, Robert H

    2016-01-01

    Immune aberrations in schizophrenia and bipolar disorder have led to the hypotheses that infectious agents or corresponding immune responses might contribute to psychiatric etiopathogeneses. We investigated case-control differences in exposure to the opportunistic fungal pathogen, Candida albicans, and examined associations with cognition, medication, lifestyle, and somatic conditions. We quantified C. albicans IgG antibodies in two cohorts totaling 947 individuals and evaluated odds ratios (OR) of exposure with psychiatric disorder using multivariate regressions. The case-control cohort included 261 with schizophrenia, 270 with bipolar disorder, and 277 non-psychiatric controls; the second included 139 with first-episode schizophrenia, 78 of whom were antipsychotic naive. No differences in C. albicans exposures were found until diagnostic groups were stratified by sex. In males, C. albicans seropositivity conferred increased odds for a schizophrenia diagnosis (OR 2.04-9.53, P⩽0.0001). In females, C. albicans seropositivity conferred increased odds for lower cognitive scores on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in schizophrenia (OR 1.12, P⩽0.004), with significant decreases on memory modules for both disorders (P⩽0.0007-0.03). C. albicans IgG levels were not impacted by antipsychotic medications. Gastrointestinal (GI) disturbances were associated with elevated C. albicans in males with schizophrenia and females with bipolar disorder (P⩽0.009-0.02). C. albicans exposure was associated with homelessness in bipolar males (P⩽0.0015). In conclusion, sex-specific C. albicans immune responses were evident in psychiatric disorder subsets. Inquiry regarding C. albicans infection or symptoms may expedite amelioration of this treatable comorbid condition. Yeast exposure as a risk factor for schizophrenia and its associated cognitive and GI effects require further investigation including the possible contribution of gut

  7. Streptococcus mutans Can Modulate Biofilm Formation and Attenuate the Virulence of Candida albicans

    PubMed Central

    Barbosa, Júnia Oliveira; Rossoni, Rodnei Dennis; Vilela, Simone Furgeri Godinho; de Alvarenga, Janaína Araújo; Velloso, Marisol dos Santos; Prata, Márcia Cristina de Azevedo; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2016-01-01

    Streptococcus mutans and Candida albicans are found together in the oral biofilms on dental surfaces, but little is known about the ecological interactions between these species. Here, we studied the effects of S. mutans UA159 on the growth and pathogencity of C. albicans. Initially, the effects of S. mutans on the biofilm formation and morphogenesis of C. albicans were tested in vitro. Next, we investigate the influence of S. mutans on pathogenicity of C. albicans using in vivo host models, in which the experimental candidiasis was induced in G. mellonella larvae and analyzed by survival curves, C. albicans count in hemolymph, and quantification of hyphae in the host tissues. In all the tests, we evaluated the direct effects of S. mutans cells, as well as the indirect effects of the subproducts secreted by this microorganism using a bacterial culture filtrate. The in vitro analysis showed that S. mutans cells favored biofilm formation by C. albicans. However, a reduction in biofilm viable cells and inhibition of hyphal growth was observed when C. albicans was in contact with the S. mutans culture filtrate. In the in vivo study, injection of S. mutans cells or S. mutans culture filtrate into G. mellonella larvae infected with C. albicans increased the survival of these animals. Furthermore, a reduction in hyphal formation was observed in larval tissues when C. albicans was associated with S. mutans culture filtrate. These findings suggest that S. mutans can secrete subproducts capable to inhibit the biofilm formation, morphogenesis and pathogenicity of C. albicans, attenuating the experimental candidiasis in G. mellonella model. PMID:26934196

  8. Effect of UV irradiation on lethal infection of mice with Candida albicans.

    PubMed

    Denkins, Y M; Kripke, M L

    1993-02-01

    Exposure of mice to UV radiation inhibits the induction and elicitation of the delayed-type hypersensitivity (DTH) response to Candida albicans. To determine whether UV irradiation also affects the pathogenesis of systemic C. albicans infection, C3H mice were exposed to a single dose of 48 kJ/m2 UV-B radiation from FS40 sunlamps 5 days before or 5 days after sensitization with formalin-fixed C. albicans and challenged intravenously (i.v.) with a lethal dose of viable fungi 6 days after sensitization (11 or 1 days after UV irradiation). Exposing unsensitized mice to UV radiation 11 days before lethal challenge had no effect on survival, but the survival time of mice exposed to UV radiation 1 day before challenge was reduced by more than 50%. In the latter group, decreased survival time correlated with persistence of C. albicans in the brain and progressive growth of C. albicans in the kidneys. Sensitization of unirradiated mice with formalin-fixed C. albicans extended their survival time following lethal i.v. challenge with viable C. albicans. Exposing the mice to UV radiation 5 days before sensitization did not abrogate this beneficial effect of sensitization on survival, even though it significantly reduced the DTH response. Thus, immunity to systemic infection did not depend on the ability of the mice to exhibit a DTH response to C. albicans. The beneficial effect of sensitization on survival after lethal infection was abrogated, however, in mice exposed to UV radiation 1 day before lethal challenge with C. albicans. Furthermore, these mice were unable to contain the progressive growth of C. albicans in the kidneys, in contrast to sensitized, unirradiated mice. PMID:8451288

  9. Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder

    PubMed Central

    Severance, Emily G; Gressitt, Kristin L; Stallings, Catherine R; Katsafanas, Emily; Schweinfurth, Lucy A; Savage, Christina L; Adamos, Maria B; Sweeney, Kevin M; Origoni, Andrea E; Khushalani, Sunil; Leweke, F Markus; Dickerson, Faith B; Yolken, Robert H

    2016-01-01

    Immune aberrations in schizophrenia and bipolar disorder have led to the hypotheses that infectious agents or corresponding immune responses might contribute to psychiatric etiopathogeneses. We investigated case–control differences in exposure to the opportunistic fungal pathogen, Candida albicans, and examined associations with cognition, medication, lifestyle, and somatic conditions. We quantified C. albicans IgG antibodies in two cohorts totaling 947 individuals and evaluated odds ratios (OR) of exposure with psychiatric disorder using multivariate regressions. The case–control cohort included 261 with schizophrenia, 270 with bipolar disorder, and 277 non-psychiatric controls; the second included 139 with first-episode schizophrenia, 78 of whom were antipsychotic naive. No differences in C. albicans exposures were found until diagnostic groups were stratified by sex. In males, C. albicans seropositivity conferred increased odds for a schizophrenia diagnosis (OR 2.04–9.53, P⩽0.0001). In females, C. albicans seropositivity conferred increased odds for lower cognitive scores on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in schizophrenia (OR 1.12, P⩽0.004), with significant decreases on memory modules for both disorders (P⩽0.0007–0.03). C. albicans IgG levels were not impacted by antipsychotic medications. Gastrointestinal (GI) disturbances were associated with elevated C. albicans in males with schizophrenia and females with bipolar disorder (P⩽0.009–0.02). C. albicans exposure was associated with homelessness in bipolar males (P⩽0.0015). In conclusion, sex-specific C. albicans immune responses were evident in psychiatric disorder subsets. Inquiry regarding C. albicans infection or symptoms may expedite amelioration of this treatable comorbid condition. Yeast exposure as a risk factor for schizophrenia and its associated cognitive and GI effects require further investigation including the possible contribution of

  10. Effect of Candida albicans on Intestinal Ischemia-reperfusion Injury in Rats

    PubMed Central

    Yan, Lei; Wu, Chun-Rong; Wang, Chen; Yang, Chun-Hui; Tong, Guang-Zhi; Tang, Jian-Guo

    2016-01-01

    Background: Inflammation is supposed to play a key role in the pathophysiological processes of intestinal ischemia-reperfusion injury (IIRI), and Candida albicans in human gut commonly elevates inflammatory cytokines in intestinal mucosa. This study aimed to explore the effect of C. albicans on IIRI. Methods: Fifty female Wistar rats were divided into five groups according to the status of C. albicans infection and IIRI operation: group blank and sham; group blank and IIRI; group cefoperazone plus IIRI; group C. albicans plus cefoperazone and IIRI (CCI); and group C. albicans plus cefoperazone and sham. The levels of inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and diamine oxidase (DAO) measured by enzyme-linked immunosorbent assay were used to evaluate the inflammation reactivity as well as the integrity of small intestine. Histological scores were used to assess the mucosal damage, and the C. albicans blood translocation was detected to judge the permeability of intestinal mucosal barrier. Results: The levels of inflammatory factors TNF-α, IL-6, and IL-1β in serum and intestine were higher in rats undergone both C. albicans infection and IIRI operation compared with rats in other groups. The levels of DAO (serum: 44.13 ± 4.30 pg/ml, intestine: 346.21 ± 37.03 pg/g) and Chiu scores (3.41 ± 1.09) which reflected intestinal mucosal disruption were highest in group CCI after the operation. The number of C. albicans translocated into blood was most in group CCI ([33.80 ± 6.60] ×102 colony forming unit (CFU)/ml). Conclusion: Intestinal C. albicans infection worsened the IIRI-induced disruption of intestinal mucosal barrier and facilitated the subsequent C. albicans translocation and dissemination. PMID:27411459

  11. Lipopeptides from Bacillus strain AR2 inhibits biofilm formation by Candida albicans.

    PubMed

    Rautela, Ria; Singh, Anil Kumar; Shukla, Abha; Cameotra, Swaranjit Singh

    2014-05-01

    The ability of the human fungal pathogen Candida albicans to reversibly switch between different morphological forms and establish biofilms is crucial for establishing infection. Targeting phenotypic plasticity and biofilm formation in C. albicans represents a new concept for antifungal drug discovery. The present study evaluated the influence of cyclic lipopeptide biosurfactant produced by Bacillus amyloliquefaciens strain AR2 on C. albicans biofilms. The biosurfactant was characterized as a mixture of iturin and fengycin by MALDI-TOF and amino acid analysis. The biosurfactant exhibited concentration dependent growth inhibition and fungicidal activity. The biosurfactant at sub-minimum growth inhibition concentration decreased cell surface hydrophobicity, hindered germ tube formation and reduced the mRNA expression of hyphae-specific gene HWP1 and ALS3 without exhibiting significant growth inhibition. The biosurfactants inhibited biofilm formation in the range of 46-100 % depending upon the concentration and Candida strains. The biosurfactant treatment dislodged 25-100 % of preformed biofilm from polystyrene plates. The biosurfactant retained its antifungal and antibiofilm activity even after exposure to extreme temperature. By virtue of the ability to inhibit germ tube and biofilm formation, two important traits of C. albicans involved in establishing infection, lipopeptides from strain AR2 may represent a potential candidate for developing heat stable anti-Candida drugs. PMID:24623107

  12. Mechanisms of adherence of Candida albicans to cultured human epidermal keratinocytes.

    PubMed Central

    Ollert, M W; Söhnchen, R; Korting, H C; Ollert, U; Bräutigam, S; Bräutigam, W

    1993-01-01

    We established an in vitro adherence model with primarily cultured human keratinocytes as target cells which allows for the investigation of the molecular mechanisms that are responsible for Candida albicans host cell attachment in the initiation of cutaneous candidosis. The extent of C. albicans binding to cultured human keratinocytes was dependent on the yeast inoculum size and the incubation temperature. Heat and paraform-aldehyde treatment of yeasts completely abolished the binding activity of C. albicans. Of the different Candida species tested, C. albicans was by far the most adhesive species. C. albicans adherence was blocked by the acid protease inhibitor pepstatin A and the metabolic inhibitor sodium azide. The latter, however, was much less effective when yeasts were preincubated, suggesting that sodium azide was mainly acting on the keratinocytes. The extracellular matrix protein fibronectin was slightly inhibitory, whereas the fibronectin-derived peptides RGD and RGDS were not able to prevent attachment. PepTite-2000, another RGD-containing synthetic peptide, reduced C. albicans adherence by a margin of 25% (P < 0.005). CDPGYIGSR-NH2, which is a synthetic adhesive peptide derived from the laminin B chain, was much more efficient in its inhibitory activity than the RGD peptides and reduced C. albicans adherence to cultured human keratinocytes up to 76% (P < 0.001). Laminin itself and the synthetic pentapeptide YIGSR were less active. A dose-dependent reduction in adherence was also observed with collagen type III. Additionally, saccharides were tested for their potential to inhibit C. albicans attachment to keratinocytes. The most potent competitive saccharide inhibitors of C. albicans adherence to human keratinocytes were the amino sugars D-(+)-glucosamine and D-(+)-galactosamine with one isolate of C. albicans (4918) and D-(+)-glucosamine and alpha-D-(+)-fucose with another C. albicans isolate (Sp-1). Collectively, our data suggest the existence of

  13. Antifungal drug resistance pattern of Candida. spp isolated from vaginitis in Ilam-Iran during 2013-2014

    PubMed Central

    Mohamadi, Jasem; Havasian, Mohamad Reza; Panahi, Jafar; Pakzad, Iraj

    2015-01-01

    Vaginal Candidiasis is the most common and important opportunistic fungal infection in women. By increasing use of antifungal drugs in recent years, it has caused drug resistance. This study aims to evaluate antifungal drugs susceptibility of Candida. spp isolated of women with vaginitis from Ilam-Iran during 2013-2014. samples were collected and cultured from 385 women with vaginitis, then Candida.spp was diagnosed by standard method. Antifungal drug susceptibility test for nystatin 100 unit/disk, fluconazole 10µg/disk, itraconazole 10µg/disk, ketoconazole 10µg/disk, amphotericinB 20µg/disk, clotrimazole 10µg/disk, posaconazole 5µg/disk, and voriconazole 1µg/disk were carried out by M44-A method(CLSI). From all culture positive samples, 150 isolates were Candida albicans and 89 isolates were non-albicans. The resistance to fluconazole, itraconazole, ketoconazole, clotrimazole, voriconazole, posaconazole, nystatin and amphotericin B was 76%, 62%, 72%, 55%, 6%, 7%, 1% and 0%. The highest resistance was seen for fluconazole , itraconazole, and the highest susceptible was seen for nystatin and amphotericin B. These results indicate nystatin and amphotericin B can be used as the first line for empirical therapy of vaginal candidiasis in the district. PMID:26124561

  14. Candida albicans-induced agglutinin and immunoglobulin E responses in mice.

    PubMed Central

    Winterrowd, G E; Cutler, J E

    1983-01-01

    Mice varied in their ability to make detectable antibody responses to cell surface determinants of Candida albicans depending upon the antigen preparation and the immunization schedule used. Immunoglobulin M (IgM) appeared to be the major class of antibody responsible for the C. albicans-agglutinating activity of the immune sera. Various inbred strains of mice injected with a ribosomal fraction from C. albicans produced a low titer (average, 4 to 8) of yeast cell agglutinins and a higher titer (64 to 512) of IgE antibodies detected by passive cutaneous anaphylaxis (PCA) in rats. The two kinds of antibodies appeared to be specific for different antigens because the agglutinin, but not IgE, could be removed by absorbing the serum with a polysaccharide from the cell wall of C. albicans, but the polysaccharide did not provoke the PCA reaction. C. albicans-specific IgE antibodies showed cross-reactivity (PCA) with ribosomal antigens from a strain of C. albicans and C. tropicalis, but PCA reactions could not be elicited with similar antigen preparations from other yeast species. IgE responses were also detected in over 20% of the mice infected intravenously or intraperitoneally with live C. albicans. PMID:6190755

  15. Streptococcus gordonii comCDE (competence) operon modulates biofilm formation with Candida albicans

    PubMed Central

    Jack, Alison A.; Daniels, Debbie E.; Jepson, Mark A.; Vickerman, M. Margaret; Lamont, Richard J.; Jenkinson, Howard F.

    2015-01-01

    Candida albicans is a pleiomorphic fungus that forms mixed species biofilms with Streptococcus gordonii, an early colonizer of oral cavity surfaces. Activation of quorum sensing (QS; intercellular signalling) promotes monospecies biofilm development by these micro-organisms, but the role of QS in mixed species communities is not understood. The comCDE genes in S. gordonii encode a sensor–regulator system (ComDE), which is activated by the comC gene product (CSP, competence stimulating peptide) and modulates expression of QS-regulated genes. Dual species biofilms of S. gordonii ΔcomCDE or ΔcomC mutants with C. albicans showed increased biomass compared to biofilms of S. gordonii DL1 wild-type with C. albicans. The ΔcomCDE mutant dual species biofilms in particular contained more extracellular DNA (eDNA), and could be dispersed with DNase I or protease treatment. Exogenous CSP complemented the S. gordonii ΔcomC transformation deficiency, as well as the ΔcomC-C. albicans biofilm phenotype. Purified CSP did not affect C. albicans hyphal filament formation but inhibited monospecies biofilm formation by C. albicans. The results suggest that the S. gordonii comCDE QS-system modulates the production of eDNA and the incorporation of C. albicans into dual species biofilms. PMID:25505189

  16. Fluconazole Resistance Candida albicans in Females With Recurrent Vaginitis and Pir1 Overexpression

    PubMed Central

    Nasrollahi, Zahra; Yadegari, Mohammad Hossein; Roudbar Mohammadi, Shahla; Roudbary, Maryam; Hosseini Poor, Maryam; Nikoomanesh, Fatemeh; Rajabi Bazl, Masumeh

    2015-01-01

    Background: Some genes may be associated with Candida albicans resistance to azoles. Pir1 gene is described as responsible to induce resistance in C. albicans. Objectives: The current study aimed to find the relationship between fluconazole resistance and Pir1 protein (Pir1p) overexpression in the females with recurrent C. albicans vaginitis requiring longer fluconazole therapy. Patients and Methods: A total of 52l vaginal samples were obtained from the females with C. albicans vaginitis. The azole susceptibility phenotype was determined according to the Clinical Laboratory for Standards Institute (CLSI) protocol for disk diffusion method and inhibition zone for fluconazole. Expression of pir1 gene and fluconazole -resistance were evaluated using polymerase chain reaction (PCR) in C. albicans. Results: In the 52 isolates, 49 (94%) were resistant to fluconazole. Overexpression of Pir1 gene was detected in 47 (96%) fluconazole-resistant C. albicans isolates. Conclusions: The findings show fluconazole -resistance in C. albicans isolates with overexpression of Pir1p. PMID:26495107

  17. Presence of extracellular DNA in the Candida albicans biofilm matrix and its contribution to biofilms

    PubMed Central

    Martins, Margarida; Uppuluri, Priya; Thomas, Derek P.; Cleary, Ian A.; Henriques, Mariana; Lopez-Ribot, José L.; Oliveira, Rosário

    2014-01-01

    DNA has been described as a structural component of the extracellular matrix (ECM) in bacterial biofilms. In Candida albicans there is a scarce knowledge concerning the contribution of extracellular DNA (eDNA) to biofilm matrix and overall structure. This work examined the presence and quantified the amount of eDNA in C.albicans biofilm ECM and the effect of DNase treatment and the addition of exogenous DNA on C. albicans biofilm development as indicators of a role for eDNA in biofilm development. We were able to detect the accumulation of eDNA in biofilm ECM extracted from C. albicans biofilms formed under conditions of flow, although the quantity of eDNA detected differed according to growth conditions, in particular with regards to the medium used to grow the biofilms. Experiments with C. albicans biofilms formed statically using a microtiter plate model indicated that the addition of exogenous DNA (>160 ng/ml) increases biofilm biomass and, conversely, DNase treatment (>0.03 mg/ml) decreases biofilm biomass at later time points of biofilm development. We present evidence for the role of eDNA in C. albicans biofilm structure and formation, consistent with eDNA being a key element of the ECM in mature C. albicans biofilms and playing a predominant role in biofilm structural integrity and maintenance. PMID:20012895

  18. Adherence of Candida albicans to a cell surface polysaccharide receptor on Streptococcus gordonii.

    PubMed Central

    Holmes, A R; Gopal, P K; Jenkinson, H F

    1995-01-01

    Candida albicans ATCC 10261 and CA2 bound to cells of the oral bacteria Streptococcus gordonii, Streptococcus oralis, and Streptococcus sanguis when these bacteria were immobilized onto microtiter plate wells, but they did not bind to cells of Streptococcus mutans or Streptococcus salivarius. Cell wall polysaccharide was extracted with alkali from S. gordonii NCTC 7869, the streptococcal species to which C. albicans bound with highest affinity, and was effective in blocking the coaggregation of C. albicans and S. gordonii cells in the fluid phase. When fixed to microtiter plate wells, the S. gordonii polysaccharide was bound by all strains of C. albicans tested. The polysaccharide contained Rha, Glc, GalNAc, GlcNAc, and Gal and was related compositionally to previously characterized cell wall polysaccharides from strains of S. oralis and S. sanguis. The adherence of yeast cells to the immobilized polysaccharide was not inhibitable by a number of saccharides. Antiserum raised to the S. gordonii NCTC 7869 polysaccharide blocked adherence of C. albicans ATCC 10261 to the polysaccharide. The results identify a complex cell wall polysaccharide of S. gordonii as the coaggregation receptor for C. albicans. Adherent interactions of yeast cells with streptococci and other bacteria may be important for colonization of both hard and soft oral surfaces by C. albicans. PMID:7729891

  19. Essential Functional Modules for Pathogenic and Defensive Mechanisms in Candida albicans Infections

    PubMed Central

    Tsai, I-Chun; Lin, Che; Chuang, Yung-Jen

    2014-01-01

    The clinical and biological significance of the study of fungal pathogen Candida albicans (C. albicans) has markedly increased. However, the explicit pathogenic and invasive mechanisms of such host-pathogen interactions have not yet been fully elucidated. Therefore, the essential functional modules involved in C. albicans-zebrafish interactions were investigated in this study. Adopting a systems biology approach, the early-stage and late-stage protein-protein interaction (PPI) networks for both C. albicans and zebrafish were constructed. By comparing PPI networks at the early and late stages of the infection process, several critical functional modules were identified in both pathogenic and defensive mechanisms. Functional modules in C. albicans, like those involved in hyphal morphogenesis, ion and small molecule transport, protein secretion, and shifts in carbon utilization, were seen to play important roles in pathogen invasion and damage caused to host cells. Moreover, the functional modules in zebrafish, such as those involved in immune response, apoptosis mechanisms, ion transport, protein secretion, and hemostasis-related processes, were found to be significant as defensive mechanisms during C. albicans infection. The essential functional modules thus determined could provide insights into the molecular mechanisms of host-pathogen interactions during the infection process and thereby devise potential therapeutic strategies to treat C. albicans infection. PMID:24757665

  20. Regulation of Candida albicans Interaction with Macrophages through the Activation of HOG Pathway by Genistein.

    PubMed

    Cui, Shuna; Hassan, Rabeay Y A; Heintz-Buschart, Anna; Bilitewski, Ursula

    2016-01-01

    The severity of infections caused by Candida albicans, the most common opportunistic human fungal pathogen, needs rapid and effective antifungal treatments. One of the effective ways is to control the virulence factors of the pathogen. Therefore, the current study examined the effects of genistein, a natural isoflavone present in soybeans, on C. albicans. The genistein-treated C. albicans cells were then exposed to macrophages. Although no inhibition effect on the growth rates of C. albicans was noted an enhancement of the immune response to macrophages has been observed, indicated by phagocytosis and release of cytokines TNF-α and IL-10. The effect of genistein on the enhanced phagocytosis can be mimicked by the fungicides fludioxonil or iprodione, which inhibit the histidine kinase Cos1p and lead to activation of HOG pathway. The western blot results showed a clear phosphorylation of Hog1p in the wild type strain of C. albicans after incubation with genistein. In addition, effects of genistein on the phosphorylation of Hog1p in the histidine kinase mutants Δcos1 and Δsln1 were also observed. Our results thus indicate a new bio-activity of genistein on C. albicans by activation of the HOG pathway of the human pathogen C. albicans. PMID:26828477

  1. Antifungal activity of Rubus chingii extract combined with fluconazole against fluconazole-resistant Candida albicans.

    PubMed

    Han, Bing; Chen, Jia; Yu, Yi-qun; Cao, Yong-bing; Jiang, Yuan-ying

    2016-02-01

    This study aimed to investigate the antifungal activity of Rubus chingii extract in combination with fluconazole (FLC) against FLC-resistant Candida albicans 100 in vitro. A R. chingii extract and FLC-resistant C. albicans fungus suspension were prepared. The minimum inhibitory concentration and fractional inhibitory concentration index of R. chingii extract combined with FLC against C. albicans were determined, after which growth curves for C. albicans treated with R. chingii extract, FLC alone and a combination of these preparations were constructed. Additionally, the mechanisms of drug combination against C. albicans were explored by flow cytometry, gas chromatographic mass spectrometry and drug efflux pump function detection. R. chingii extract combined with FLC showed significant synergy. Flow cytometry suggested that C. albicans cells mainly arrest in G1 and S phases when they have been treated with the drug combination. The drug combination resulted in a marked decrease in the ergosterol content of the cell membrane. Additionally, efflux of Rhodamine 6G decreased with increasing concentrations of R. chingii extract. R. chingii extract combined with FLC has antifungal activity against FLC-resistant C. albicans. PMID:26891940

  2. Quantitative and qualitative analyses of the cell death process in Candida albicans treated by antifungal agents.

    PubMed

    Kim, Kyung Sook; Kim, Young-Sun; Han, Ihn; Kim, Mi-Hyun; Jung, Min Hyung; Park, Hun-Kuk

    2011-01-01

    The death process of Candida albicans was investigated after treatment with the antifungal agents flucytosine and amphotericin B by assessing morphological and biophysical properties associated with cell death. C. albicans was treated varying time periods (from 6 to 48 hours) and examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM and AFM images clearly showed changes in morphology and biophysical properties. After drug treatment, the membrane of C. albicans was perforated, deformed, and shrunken. Compared to the control, C. albicans treated with flucytosine was softer and initially showed a greater adhesive force. Conversely, C. albicans treated with amphotericin B was harder and had a lower adhesive force. In both cases, the surface roughness increased as the treatment time increased. The relationships between morphological changes and the drugs were observed by AFM clearly; the surface of C. albicans treated with flucytosine underwent membrane collapse, expansion of holes, and shrinkage, while the membranes of cells treated with amphotericin B peeled off. According to these observations, the death process of C. albicans was divided into 4 phases, CDP(0), CDP(1), CDP(2), and CDP(4), which were determined based on morphological changes. Our results could be employed to further investigate the antifungal activity of compounds derived from natural sources. PMID:22174777

  3. Prevalence and antifungal susceptibility of Candida albicans and its related species Candida dubliniensis and Candida africana isolated from vulvovaginal samples in a hospital of Argentina.

    PubMed

    Theill, Laura; Dudiuk, Catiana; Morano, Susana; Gamarra, Soledad; Nardin, María Elena; Méndez, Emilce; Garcia-Effron, Guillermo

    2016-01-01

    Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates. PMID:26922471

  4. Beyond the wall: Candida albicans secret(e)s to survive.

    PubMed

    Sorgo, Alice G; Heilmann, Clemens J; Brul, Stanley; de Koster, Chris G; Klis, Frans M

    2013-01-01

    The opportunistic fungal pathogen Candida albicans occupies various niches of the human body such as the skin and the mucosal surfaces of the gastrointestinal and urogenital tracts. It can also enter the blood stream and cause deadly, systemic infections, especially in immunocompromised patients, but also in immunocompetent individuals through inserted medical devices. To survive in these diverse host environments, C. albicans has developed specialized virulence attributes and rapidly adapts itself to local growth conditions and defense mechanisms. Candida albicans secretes a considerable number of proteins that are involved in biofilm formation, tissue invasion, immune evasion, and wall maintenance, as well as acquisition of nutrients including metal ions. The secretome of C. albicans is predicted to comprise 225 proteins. On a proteomic level, however, analysis of the secretome of C. albicans is incomplete as many secreted proteins are only produced under certain conditions. Interestingly, glycosylphosphatidylinositol proteins and known cytoplasmic proteins are also consistently detected in the growth medium. Importantly, a core set of seven wall polysaccharide-processing enzymes seems to be consistently present, including the diagnostic marker Mp65. Overall, we discuss the importance of the secretome for virulence and suggest potential targets for better and faster diagnostic methods. PMID:23170918

  5. The Extracellular Matrix of Candida albicans Biofilms Impairs Formation of Neutrophil Extracellular Traps.

    PubMed

    Johnson, Chad J; Cabezas-Olcoz, Jonathan; Kernien, John F; Wang, Steven X; Beebe, David J; Huttenlocher, Anna; Ansari, Hamayail; Nett, Jeniel E

    2016-09-01

    Neutrophils release extracellular traps (NETs) in response to planktonic C. albicans. These complexes composed of DNA, histones, and proteins inhibit Candida growth and dissemination. Considering the resilience of Candida biofilms to host defenses, we examined the neutrophil response to C. albicans during biofilm growth. In contrast to planktonic C. albicans, biofilms triggered negligible release of NETs. Time lapse imaging confirmed the impairment in NET release and revealed neutrophils adhering to hyphae and migrating on the biofilm. NET inhibition depended on an intact extracellular biofilm matrix as physical or genetic disruption of this component resulted in NET release. Biofilm inhibition of NETosis could not be overcome by protein kinase C activation via phorbol myristate acetate (PMA) and was associated with suppression of neutrophil reactive oxygen species (ROS) production. The degree of impaired NET release correlated with resistance to neutrophil attack. The clinical relevance of the role for extracellular matrix in diminishing NET production was corroborated in vivo using a rat catheter model. The C. albicans pmr1Δ/Δ, defective in production of matrix mannan, appeared to elicit a greater abundance of NETs by scanning electron microscopy imaging, which correlated with a decreased fungal burden. Together, these findings show that C. albicans biofilms impair neutrophil response through an inhibitory pathway induced by the extracellular matrix. PMID:27622514

  6. Transcriptional regulation of drug-resistance genes in Candida albicans biofilms in response to antifungals.

    PubMed

    Watamoto, T; Samaranayake, L P; Egusa, H; Yatani, H; Seneviratne, C J

    2011-09-01

    Biofilm formation is a major virulence attribute of Candida albicans and is directly associated with therapeutic failure. One method by which Candida acquires antifungal resistance is the expression of drug-resistance genes. This study aimed to evaluate the transcriptional regulation of several genes associated with antifungal resistance of C. albicans under planktonic, recently adhered and biofilm growth modes and in C. albicans biofilms in response to antifungal agents. Initially, the antifungal susceptibility of C. albicans cultures in different growth modes was evaluated by standard antifungal susceptibility testing. Next, to assess CDR1, CDR2, MDR1, ERG11, FKS1 and PIL1 expression, RNA was harvested from cells in each growth mode, and from biofilms after drug treatment, and subjected to quantitative real-time RT-PCR (qRT-PCR). Biofilm C. albicans was more resistant to antifungals than recently adhered cells and stationary-phase planktonic cultures. Transcriptional expression of CDR1, CDR2, MDR1, ERG11 and FKS1 was lower in recently adhered C. albicans than in the stationary-phase planktonic cultures. In contrast, PIL1 levels were significantly increased in recently adhered and biofilm modes of growth. The expression of MDR1 in biofilms greatly increased on challenge with amphotericin B but not with the other drugs tested (P<0.01). ERG11 was significantly upregulated by ketoconazole (P<0.01). Caspofungin and amphotericin B significantly upregulated FKS1 expression, whereas they significantly downregulated PIL1 expression (P<0.01). These results indicate that the expression of drug-resistance genes is associated with higher drug resistance of Candida biofilms, and lay a foundation for future large-scale genome-wide expression analysis. PMID:21474609

  7. Candida albicans-epithelial interactions and pathogenicity mechanisms: scratching the surface

    PubMed Central

    Moyes, David L; Richardson, Jonathan P; Naglik, Julian R

    2015-01-01

    Until recently, epithelial cells have been a largely ignored component of host responses to microbes. However, this has been largely overturned over the last decade as an ever increasing number of studies have highlighted the key role that these cells play in many of our interactions with our microbiota and pathogens. Interactions of these cells with Candida albicans have been shown to be critical not just in host responses, but also in fungal cell responses, regulating fungal morphology and gene expression profile. In this review, we will explore the interactions between C. albicans and epithelial cells, and discuss how these interactions affect our relationship with this fungus. PMID:25714110

  8. Attachment of Candida albicans to denture base acrylic resin processed by three different methods.

    PubMed

    Young, Beth; Jose, Anto; Cameron, Donald; McCord, Fraser; Murray, Colin; Bagg, Jeremy; Ramage, Gordon

    2009-01-01

    Denture stomatitis is a debilitating disease associated with the presence of adherent Candida albicans. This study compared the attachment capacity of C. albicans to three different acrylic resin materials (self-curing [SC], conventional pressure-packed [CPP], and injection-molded [IM]) to determine whether the physical properties of the materials influenced candidal attachment. No significant differences in attachment between the isolates were observed for each acrylic resin. However, a comparison of the mean of all isolates showed significantly less attachment to SC than to CPP (P < .05). These data indicate that choice of denture acrylic resin material may influence the capacity for developing denture stomatitis. PMID:20095199

  9. Comparative Analysis of Protein Glycosylation Pathways in Humans and the Fungal Pathogen Candida albicans

    PubMed Central

    Martínez-Duncker, Iván; Díaz-Jímenez, Diana F.; Mora-Montes, Héctor M.

    2014-01-01

    Protein glycosylation pathways are present in all kingdoms of life and are metabolic pathways found in all the life kingdoms. Despite sharing commonalities in their synthesis, glycans attached to glycoproteins have species-specific structures generated by the presence of different sets of enzymes and acceptor substrates in each organism. In this review, we present a comparative analysis of the main glycosylation pathways shared by humans and the fungal pathogen Candida albicans: N-linked glycosylation, O-linked mannosylation and glycosylphosphatidylinositol-anchorage. The knowledge of similarities and divergences between these metabolic pathways could help find new pharmacological targets for C. albicans infection. PMID:25104959

  10. Post-transcriptional gene regulation in the biology and virulence of Candida albicans.

    PubMed

    Verma-Gaur, Jiyoti; Traven, Ana

    2016-06-01

    In the human fungal pathogen Candida albicans, remodelling of gene expression drives host adaptation and virulence. Recent studies revealed that in addition to transcription, post-transcriptional mRNA control plays important roles in virulence-related pathways. Hyphal morphogenesis, biofilm formation, stress responses, antifungal drug susceptibility and virulence in animal models require post-transcriptional regulators. This includes RNA binding proteins that control mRNA localization, decay and translation, as well as the cytoplasmic mRNA decay pathway. Comprehensive understanding of how modulation of gene expression networks drives C. albicans virulence will necessitate integration of our knowledge on transcriptional and post-transcriptional mRNA control. PMID:26999710

  11. Antagonism of Fluconazole and a Proton Pump Inhibitor against Candida albicans

    PubMed Central

    Liu, Ning-Ning

    2015-01-01

    Hospitalized ill patients, at risk for invasive candidiasis, often receive multiple medications, including proton pump inhibitors (PPIs). The antifungal fluconazole perturbs the vacuolar proton ATPase. The PPI omeprazole antagonized Candida albicans growth inhibition by fluconazole. A C. albicans codon-adapted pHluorin, Ca.pHluorin, was generated to measure cytosolic pH. The fungal cytosol was acidified by omeprazole and realkalinized by coexposure to fluconazole. Vacuolar pH was alkalinized by fluconazole. Off-target effects of any medication on fungal pathogens may occur. PMID:26596946

  12. Roles of IL-33 in Resistance and Tolerance to Systemic Candida albicans Infections

    PubMed Central

    Park, Sang Jun; Cho, Hong Rae

    2016-01-01

    IL-33 is a multifunctional cytokine that is released in response to a variety of intrinsic and extrinsic stimuli. The role of IL-33 in Candida albicans infections is just beginning to be revealed. This cytokine has beneficial effects on host defense against systemic C. albicans infections, and it promotes resistance mechanisms by which the immune system eliminates the invading fungal pathogens; and it also elevates host tolerance by reducing the inflammatory response and thereby, potentially, tissue damage. Thus, IL-33 is classified as a cytokine that has evolved functionally to protect the host from damage by pathogens and immunopathology. PMID:27340384

  13. Comparison of Switching and Biofilm Formation between MTL-Homozygous Strains of Candida albicans and Candida dubliniensis

    PubMed Central

    Pujol, Claude; Daniels, Karla J.

    2015-01-01

    Candida albicans and Candida dubliniensis are highly related species that share the same main developmental programs. In C. albicans, it has been demonstrated that the biofilms formed by strains heterozygous and homozygous at the mating type locus (MTL) differ functionally, but studies rarely identify the MTL configuration. This becomes a particular problem in studies of C. dubliniensis, given that one-third of natural strains are MTL homozygous. For that reason, we have analyzed MTL-homozygous strains of C. dubliniensis for their capacity to switch from white to opaque, the stability of the opaque phenotype, CO2 induction of switching, pheromone induction of adhesion, the effects of minority opaque cells on biofilm thickness and dry weight, and biofilm architecture in comparison with C. albicans. Our results reveal that C. dubliniensis strains switch to opaque at lower average frequencies, exhibit a far lower level of opaque phase stability, are not stimulated to switch by high CO2, exhibit more variability in biofilm architecture, and most notably, form mature biofilms composed predominately of pseudohyphae rather than true hyphae. Therefore, while several traits of MTL-homozygous strains of C. dubliniensis appear to be degenerating or have been lost, others, most notably several related to biofilm formation, have been conserved. Within this context, the possibility is considered that C. dubliniensis is transitioning from a hypha-dominated to a pseudohypha-dominated biofilm and that aspects of C. dubliniensis colonization may provide insights into the selective pressures that are involved. PMID:26432632

  14. Candida albicans biofilm inhibition by synergistic action of terpenes and fluconazole.

    PubMed

    Pemmaraju, Suma C; Pruthi, Parul A; Prasad, R; Pruthi, Vikas

    2013-11-01

    The current treatment options for Candida albicans biofilm-device related infections are very scarce due to their intrinsic increased tolerance to antimycotics. The aim of this work was to study synergistic action of terpenes (eugenol, menthol and thymol) with fluconazole (FLA) on C. albicans biofilm inhibition. The minimum inhibitory concentration (MIC) assayed using CLSI M27-A3 broth micro-dilution method showed antifungal activity against C. albicans MTCC 227 at a concentration of 0.12 % (v/v) for both thymol and eugenol as compared to 0.25 % (v/v) for menthol. FLA was taken as positive control. The effect of these terpenes on metabolic activity of preformed C. albicans biofilm cells was evaluated using 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay in 96-well polystyrene microtiter plate. Thymol and eugenol were more effective at lower concentrations of > or = 1.0 % (v/v) than menthol. Synergistic studies using checkerboard micro-dilution assay showed fractional inhibitory concentration index (sigma FIC = 0.31) between thymol/FLA followed by eugenol/FLA (sigma FIC = 0.37) and menthol/FLA (sigma FIC < 0.5) against pre-formed C. albicans biofilms. Thymol with fluconazole showed highest synergy in reduction of biofilm formation than eugenol and menthol which was not observed when their activities were observed independently. Adherence assay showed 30% viability of C. albicans cells after 2 h of treatment with 0.05 % (v/v) thymol/FLA. Effect of thymol/FLA on C. albicans adhesion visualized by SEM micrographs showed disruption in number of candidal cells and alteration in structural design of C. albicans. Thus, the study demonstrated synergistic effect of terpenes with fluconazole on C. albicans biofilm, which could be future medications for biofilm infections. PMID:24416942

  15. Function and subcellular localization of Gcn5, a histone acetyltransferase in Candida albicans.

    PubMed

    Chang, Peng; Fan, Xueyi; Chen, Jiangye

    2015-08-01

    Candida albicans is an opportunistic fungal pathogen commonly found in humans. It has the ability to switch reversibly between three growth forms: budding yeast, pseudohypha, and hypha. The transition between yeast and hyphal growth forms is critical for the pathogenesis of C. albicans. During the yeast-to-hypha morphologic transition, gene expression is regulated by transcriptional regulators including histone modifying complexes and chromatin remodeling complexes. We previously reported that Esa1, a catalytic subunit in the histone acetyltransferase complex NuA4, is essential for the hyphal development of C. albicans. In this study, we analyzed the functional roles of Gcn5, a catalytic subunit in the histone acetyltransferase complex SAGA, in C. albicans. Gcn5 is required for the invasive and filamentous growth of C. albicans. Deletion of GCN5 impaired hyphal elongation in sensing serum and attenuated the virulence of C. albicans in a mouse systemic infection model. The C. albicans gcn5/gcn5 mutant cells also exhibited sensitivity to cell wall stress. Functional analysis showed that the HAT domain and Bromodomain in Gcn5 play distinct roles in morphogenesis and cell wall stress response of C. albicans. Our results show that the conserved residue Glu188 is crucial for the Gcn5 HAT activity and for Gcn5 function during filamentous growth. In addition, the subcellular distribution of ectopically expressed GFP-Gcn5 correlates with the different growth states of C. albicans. In stationary phase, Gcn5 accumulated in the nucleus, while during vegetative growth it localized in the cytoplasm in a morpha-independent manner. Our results suggest that the nuclear localization of Gcn5 depends on the existence of its N-terminal NLS and HAT domains. PMID:25656079

  16. Reduced susceptibility of Candida albicans clinical isolates to azoles and detection of mutations in the ERG11 gene.

    PubMed

    Zhang, Lei; Yang, Hai-Fei; Liu, Yan-Yan; Xu, Xi-Hai; Ye, Ying; Li, Jia-Bin

    2013-12-01

    We investigated the susceptibility of Candida albicans isolated from clinic specimens to azole antifungal agents and estimated the association of the ERG11 mutations with azole resistance during recent 5years in China. In this study, novel mutations G346A, A434V, and L480F in ERG11 may be related to azole resistance in C. albicans. PMID:24070847

  17. A Candida albicans CRISPR system permits genetic engineering of essential genes and gene families

    PubMed Central

    Vyas, Valmik K.; Barrasa, M. Inmaculada; Fink, Gerald R.

    2015-01-01

    Candida albicans is a pathogenic yeast that causes mucosal and systematic infections with high mortality. The absence of facile molecular genetics has been a major impediment to analysis of pathogenesis. The lack of meiosis coupled with the absence of plasmids makes genetic engineering cumbersome, especially for essential functions and gene families. We describe a C. albicans CRISPR system that overcomes many of the obstacles to genetic engineering in this organism. The high frequency with which CRISPR-induced mutations can be directed to target genes enables easy isolation of homozygous gene knockouts, even without selection. Moreover, the system permits the creation of strains with mutations in multiple genes, gene families, and genes that encode essential functions. This CRISPR system is also effective in a fresh clinical isolate of undetermined ploidy. Our method transforms the ability to manipulate the genome of Candida and provides a new window into the biology of this pathogen. PMID:25977940

  18. Candida albicans--adriamycin interactions: ultrastructural and spectrofluorometric study of whole yeasts and spheroplasts.

    PubMed

    Bobichon, H; Bussy, V; Angiboust, J F; Manfait, M; Bouchet, P; Jardillier, J C

    1990-01-01

    The occurrence of candidiasis in cancer patients who undergo chemotherapy requires the interrelation of Candida albicans and the antimitotic drug Adriamycin (ADM) which is well known as an intercalating agent. The whole yeasts were not affected by 2 h of contact with the drug at 10(-4) M neither for their growth curve nor for their ultrastructure, despite the presence of free ADM on their surface. Spheroplasts displayed a delay in their growth and exhibited altered nucleoli with segregation of their granular and fibrillar components. The modified emission spectrum of ADM, determined by spectrofluorometry, corresponded neither to the free ADM nor to the DNA-bound drug, but it could be related to a metabolite of the drug. The cell wall appeared to be one of the main sites for ADM resistance of Candida albicans in vitro. PMID:2085691

  19. Effects of Ploidy and Mating Type on Virulence of Candida albicans

    PubMed Central

    Ibrahim, Ashraf S.; Magee, B. B.; Sheppard, D. C.; Yang, Molly; Kauffman, Sarah; Becker, Jeff; Edwards, John E.; Magee, P. T.

    2005-01-01

    Candida albicans is the most common fungal pathogen of humans. The recent discovery of sexuality in this organism has led to the demonstration of a mating type locus which is usually heterozygous, although some isolates are homozygous. Tetraploids can be formed between homozygotes of the opposite mating type. However, the role of the mating process and tetraploid formation in virulence has not been investigated. We describe here experiments using a murine model of disseminated candidiasis which demonstrate that in three strains, including CAI-4, the most commonly used strain background, tetraploids are less virulent than diploids and can undergo changes in ploidy during infection. In contrast to reports with other strains, we find that MTL homozygotes are almost as virulent as the heterozygotes. These results show that the level of ploidy in Candida albicans can affect virulence, but the mating type configuration does not necessarily do so. PMID:16239535

  20. Members of the Candida parapsilosis Complex and Candida albicans are Differentially Recognized by Human Peripheral Blood Mononuclear Cells

    PubMed Central

    Estrada-Mata, Eine; Navarro-Arias, María J.; Pérez-García, Luis A.; Mellado-Mojica, Erika; López, Mercedes G.; Csonka, Katalin; Gacser, Attila; Mora-Montes, Héctor M.

    2016-01-01

    The systemic infections caused by members of the Candida parapsilosis complex are currently associated to high morbility and mortality rates, and are considered as relevant as those caused by Candida albicans. Since the fungal cell wall is the first point of contact with the host cells, here we performed a comparison of this organelle in members of the C. parapsilosis complex, and its relevance during interaction with human peripheral blood mononuclear cells (PBMCs). We found that the wall of the C. parapsilosis complex members is similar in composition, but differs to that from C. albicans, with less mannan content and more β-glucan and porosity levels. Furthermore, lectin-based analysis showed increased chitin and β1,3-glucan exposure at the surface of C. parapsilosis sensu lato when compared to C. albicans. Yeast cells of members of the C. parapsilosis complex stimulated more cytokine production by human PBMCs than C. albicans cells; and this significantly changed upon removal of O-linked mannans, indicating this wall component plays a significant role in cytokine stimulation by C. parapsilosis sensu lato. When inner wall components were exposed on the wall surface, C. parapsilosis sensu stricto and C. metapsilosis, but not C. orthopsilosis, stimulated higher cytokine production. Moreover, we found a strong dependency on β1,3-glucan recognition for the members of the C. parapsilosis complex, but not for live C. albicans cells; whereas TLR4 was required for TNFα production by the three members of the complex, and stimulation of IL-6 by C. orthopsilosis. Mannose receptor had a significant role during TNFα and IL-1β stimulation by members of the complex. Finally, we demonstrated that purified N- and O-mannans from either C. parapsilosis sensu lato or C. albicans are capable to block the recognition of these pathogens by human PBMCs. Together; our results suggest that the innate immune recognition of the members of the C. parapsilosis complex is differential

  1. Anaerobic bacteria grow within Candida albicans biofilms and induce biofilm formation in suspension cultures.

    PubMed

    Fox, Emily P; Cowley, Elise S; Nobile, Clarissa J; Hartooni, Nairi; Newman, Dianne K; Johnson, Alexander D

    2014-10-20

    The human microbiome contains diverse microorganisms, which share and compete for the same environmental niches. A major microbial growth form in the human body is the biofilm state, where tightly packed bacterial, archaeal, and fungal cells must cooperate and/or compete for resources in order to survive. We examined mixed biofilms composed of the major fungal species of the gut microbiome, Candida albicans, and each of five prevalent bacterial gastrointestinal inhabitants: Bacteroides fragilis, Clostridium perfringens, Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. We observed that biofilms formed by C. albicans provide a hypoxic microenvironment that supports the growth of two anaerobic bacteria, even when cultured in ambient oxic conditions that are normally toxic to the bacteria. We also found that coculture with bacteria in biofilms induces massive gene expression changes in C. albicans, including upregulation of WOR1, which encodes a transcription regulator that controls a phenotypic switch in C. albicans, from the "white" cell type to the "opaque" cell type. Finally, we observed that in suspension cultures, C. perfringens induces aggregation of C. albicans into "mini-biofilms," which allow C. perfringens cells to survive in a normally toxic environment. This work indicates that bacteria and C. albicans interactions modulate the local chemistry of their environment in multiple ways to create niches favorable to their growth and survival. PMID:25308076

  2. Effect of emodin on Candida albicans growth investigated by microcalorimetry combined with chemometric analysis.

    PubMed

    Kong, W J; Wang, J B; Jin, C; Zhao, Y L; Dai, C M; Xiao, X H; Li, Z L

    2009-07-01

    Using the 3114/3115 thermal activity monitor (TAM) air isothermal microcalorimeter, ampoule mode, the heat output of Candida albicans growth at 37 degrees C was measured, and the effect of emodin on C. albicans growth was evaluated by microcalorimetry coupled with chemometric methods. The similarities between the heat flow power (HFP)-time curves of C. albicans growth affected by different concentrations of emodin were calculated by similarity analysis (SA). In the correspondence analysis (CA) diagram of eight quantitative parameters taken from the HFP-time curves, it could be deduced that emodin had definite dose-effect relationship as the distance between different concentrations of it increased along with the dosage and the effect. From the principal component analysis (PCA) on eight quantitative parameters, the action of emodin on C. albicans growth could be easily evaluated by analyzing the change of values of the main two parameters, growth rate constant k (2) and maximum power output P(2)(m). The coherent results of SA, CA, and PCA showed that emodin at different concentrations had different effects on C. albicans growth metabolism: A low concentration (0-10 microg ml(-1)) poorly inhibited the growth of C. albicans, and a high concentration (15-35 microg ml(-1)) could notably inhibit growth of this fungus. This work provided a useful idea of the combination of microcalorimetry and chemometric analysis for investigating the effect of drug and other compounds on microbes. PMID:19543891

  3. Candida albicans adapts to host copper during infection by swapping metal cofactors for superoxide dismutase

    PubMed Central

    Li, Cissy X.; Gleason, Julie E.; Zhang, Sean X.; Bruno, Vincent M.; Cormack, Brendan P.; Culotta, Valeria Cizewski

    2015-01-01

    Copper is both an essential nutrient and potentially toxic metal, and during infection the host can exploit Cu in the control of pathogen growth. Here we describe a clever adaptation to Cu taken by the human fungal pathogen Candida albicans. In laboratory cultures with abundant Cu, C. albicans expresses a Cu-requiring form of superoxide dismutase (Sod1) in the cytosol; but when Cu levels decline, cells switch to an alternative Mn-requiring Sod3. This toggling between Cu- and Mn-SODs is controlled by the Cu-sensing regulator Mac1 and ensures that C. albicans maintains constant SOD activity for cytosolic antioxidant protection despite fluctuating Cu. This response to Cu is initiated during C. albicans invasion of the host where the yeast is exposed to wide variations in Cu. In a murine model of disseminated candidiasis, serum Cu was seen to progressively rise over the course of infection, but this heightened Cu response was not mirrored in host tissue. The kidney that serves as the major site of fungal infection showed an initial rise in Cu, followed by a decline in the metal. C. albicans adjusted its cytosolic SODs accordingly and expressed Cu-Sod1 at early stages of infection, followed by induction of Mn-Sod3 and increases in expression of CTR1 for Cu uptake. Together, these studies demonstrate that fungal infection triggers marked fluctuations in host Cu and C. albicans readily adapts by modulating Cu uptake and by exchanging metal cofactors for antioxidant SODs. PMID:26351691

  4. Anti-fungal activity of cathelicidins and their potential role in Candida albicans skin infection.

    PubMed

    López-García, Belén; Lee, Phillip H A; Yamasaki, Kenshi; Gallo, Richard L

    2005-07-01

    Cathelicidins have broad anti-microbial capacity and are important for host defense against skin infections by some bacterial and viral pathogens. This study investigated the activity of cathelicidins against Candida albicans. The human cathelicidin LL-37, and mouse cathelicidin mCRAMP, killed C. albicans, but this fungicidal activity was dependent on culture conditions. Evaluation of the fungal membrane by fluorescent dye penetration after incubation with cathelicidins correlated membrane permeabilization and inhibition of fungal growth. Anti-fungal assays carried out in an ionic environment that mimicked human sweat and with the processed forms of cathelicidin such as are present in sweat found that the cleavage of LL-37 to forms such as RK-31 conferred additional activity against C. albicans. C. albicans also induced an increase in the expression of cathelicidin in mouse skin, but this induction did not confer systemic or subcutaneous resistance as mCRAMP-deficient mice were not more susceptible to C. albicans in blood-killing assays or in an intradermal infection model. Therefore, cathelicidins appear active against C. albicans, but may be most effective as a superficial barrier to infection. PMID:15982310

  5. Innate Immunity and Saliva in Candida albicans-mediated Oral Diseases.

    PubMed

    Salvatori, O; Puri, S; Tati, S; Edgerton, M

    2016-04-01

    The oral cavity is a unique niche where Candida albicans infections occur in immunocompetent as well as immunosuppressed individuals. Here we critically review the significance of human innate immune response in preventing oral candidiasis. One important line of defense against oropharyngeal candidiasis is the oral microbiota that prevents infection by competing for space and nutrients as well as by secreting antagonistic molecules and triggering local inflammatory responses. C. albicans is able to induce mucosal defenses through activation of immune cells and production of cytokines. Also, saliva contains various proteins that affect C. albicans growth positively by promoting mucosal adherence and negatively through immune exclusion and direct fungicidal activity. We further discuss the role of saliva in unifying host innate immune defenses against C. albicans as a communicating medium and how C. albicans overgrowth in the oral cavity may be a result of aberrations ranging from microbial dysbiosis and salivary dysfunction to epithelial damage. Last we underscore select oral diseases in which C. albicans is a contributory microorganism in immune-competent individuals. PMID:26747422

  6. Genetic organization and mRNA expression of enolase genes of Candida albicans.

    PubMed

    Postlethwait, P; Sundstrom, P

    1995-04-01

    In previous work, we cloned a Candida albicans cDNA for the glycolytic enzyme enolase and found a single, abundant enolase transcript on Northern (RNA) blots and a single protein on immunoblots, using antiserum raised against a recombinant enolase fusion protein. Because C. albicans enolase is abundantly produced during infection and elicits strong host immune responses, the mechanisms regulating enolase production are important for understanding the growth of C. albicans in vivo. To obtain more information on enolase gene expression by C. albicans, we used the enolase cDNA clone to investigate the genetic organization of enolase genes and the steady-state levels of enolase mRNA under several growth conditions. Gene disruption techniques in combination with Southern blot analyses of genomic DNA showed the presence of two enolase gene loci that could be distinguished by the locations of ClaI and Mn/I sites in their 3' flanking regions. Enolase steady-state mRNA levels were greatest during the middle phase of the logarithmic growth curve and were low during stationary phase. Minimal differences in enolase mRNA levels between yeast cells and hyphae were found. Propagation of C. albicans in glucose did not cause increased enolase mRNA levels compared with growth in a nonfermentable carbon source (pyruvate). It was concluded that two gene loci exist for C. albicans enolase and that enolase mRNA is constitutively produced at high levels during active metabolism. PMID:7896700

  7. Opportunistic pathogen Candida albicans elicits a temporal response in primary human mast cells

    PubMed Central

    Lopes, José Pedro; Stylianou, Marios; Nilsson, Gunnar; Urban, Constantin F.

    2015-01-01

    Immunosuppressed patients are frequently afflicted with severe mycoses caused by opportunistic fungal pathogens. Besides being a commensal, colonizing predominantly skin and mucosal surfaces, Candida albicans is the most common human fungal pathogen. Mast cells are present in tissues prone to fungal colonization being expectedly among the first immune cells to get into contact with C. albicans. However, mast cell-fungus interaction remains a neglected area of study. Here we show that human mast cells mounted specific responses towards C. albicans. Collectively, mast cell responses included the launch of initial, intermediate and late phase components determined by the secretion of granular proteins and cytokines. Initially mast cells reduced fungal viability and occasionally internalized yeasts. C. albicans could evade ingestion by intracellular growth leading to cellular death. Furthermore, secreted factors in the supernatants of infected cells recruited neutrophils, but not monocytes. Late stages were marked by the release of cytokines that are known to be anti-inflammatory suggesting a modulation of initial responses. C. albicans-infected mast cells formed extracellular DNA traps, which ensnared but did not kill the fungus. Our results suggest that mast cells serve as tissue sentinels modulating antifungal immune responses during C. albicans infection. Consequently, these findings open new doors for understanding fungal pathogenicity. PMID:26192381

  8. Candida albicans adapts to host copper during infection by swapping metal cofactors for superoxide dismutase.

    PubMed

    Li, Cissy X; Gleason, Julie E; Zhang, Sean X; Bruno, Vincent M; Cormack, Brendan P; Culotta, Valeria Cizewski

    2015-09-22

    Copper is both an essential nutrient and potentially toxic metal, and during infection the host can exploit Cu in the control of pathogen growth. Here we describe a clever adaptation to Cu taken by the human fungal pathogen Candida albicans. In laboratory cultures with abundant Cu, C. albicans expresses a Cu-requiring form of superoxide dismutase (Sod1) in the cytosol; but when Cu levels decline, cells switch to an alternative Mn-requiring Sod3. This toggling between Cu- and Mn-SODs is controlled by the Cu-sensing regulator Mac1 and ensures that C. albicans maintains constant SOD activity for cytosolic antioxidant protection despite fluctuating Cu. This response to Cu is initiated during C. albicans invasion of the host where the yeast is exposed to wide variations in Cu. In a murine model of disseminated candidiasis, serum Cu was seen to progressively rise over the course of infection, but this heightened Cu response was not mirrored in host tissue. The kidney that serves as the major site of fungal infection showed an initial rise in Cu, followed by a decline in the metal. C. albicans adjusted its cytosolic SODs accordingly and expressed Cu-Sod1 at early stages of infection, followed by induction of Mn-Sod3 and increases in expression of CTR1 for Cu uptake. Together, these studies demonstrate that fungal infection triggers marked fluctuations in host Cu and C. albicans readily adapts by modulating Cu uptake and by exchanging metal cofactors for antioxidant SODs. PMID:26351691

  9. Plasma-membrane Cnh1 Na+/H+ antiporter regulates potassium homeostasis in Candida albicans.

    PubMed

    Kinclova-Zimmermannova, Olga; Sychrová, Hana

    2007-08-01

    The physiological role of Candida albicans Cnh1, a member of the Na+/H+ antiporter family, was characterized. Though CaCnh1p had broad substrate specificity and mediated efflux of at least four alkali metal cations upon heterologous expression in Saccharomyces cerevisiae, its presence in C. albicans cells was important especially for potassium homeostasis. In C. albicans, CaCnh1p tagged with GFP was localized in the plasma membrane of cells growing as both yeasts and hyphae. Deletion of CNH1 alleles did not affect tolerance to NaCl, LiCl or CsCl, but resulted in increased sensitivity to high external concentrations of KCl and RbCl. The potassium and rubidium tolerance of a cnh1 homozygous mutant was fully restored by reintegration of CNH1 into the genome. The higher sensitivity of the cnh1/cnh1 mutant to external KCl was caused by a lower K+ efflux from these cells. Together, the functional characterization of the CaCnh1 antiporter in C. albicans revealed that this antiporter plays a significant role in C. albicans physiology. It ensures potassium and rubidium tolerance and participates in the regulation of intracellular potassium content of C. albicans cells. PMID:17660424

  10. In Vitro Antifungal Susceptibility Profiles of Candida albicans Complex Isolated from Patients with Respiratory Infections.

    PubMed

    Sharifynia, Somayeh; Badali, Hamid; Sharifi Sorkherizi, Mina; Shidfar, Mohammad Reza; Hadian, Atefe; Shahrokhi, Shadi; Ghandchi, Ghazale; Rezaie, Sassan

    2016-06-01

    Candidiasis, the main opportunistic fungal infection has been increased over the past decades. This study aimed to characterize C.albicans species complex (C.albicans, C.dubliniensis, and C.africana) isolated from patients with respiratory infections by molecular tools and in vitro antifungal susceptibilities by using broth microdilution method according to CLSI M27-A3 guidelines. Totally, 121 respiratory samples were collected from patients with respiratory infections. Of these, 83 strains were germ tube positive and green colonies on chromogenic media, so initially identified as C.albicans species complex and subsequently were classified as C.albicans (89.15%), C.dubliniensis (9.63%), and C.africana (1.2%) based on PCR-RFLP and amplification of hwp1 gene. Minimum inhibitory concentration (MICs) results showed that all tested isolates of C.albicans complex were highly susceptible to triazole drugs. However, caspofungin had highest activity against C.albicans, C.dubliniensis, and C.africana. Our findings indicated the variety of antifungal resistance of Candida strains in different areas. These results may increase the knowledge about the local distribution of the mentioned strains as well as their antifungal susceptibility pattern which play an important role in appropriate therapy. PMID:27306344

  11. Hyphal formation of Candida albicans is controlled by electron transfer system

    SciTech Connect

    Watanabe, Toshihiko . E-mail: twatanab@tohoku-pharm.ac.jp; Ogasawara, Ayako; Mikami, Takeshi; Matsumoto, Tatsuji

    2006-09-15

    Most Candida albicans cells cultured in RPMI1640 medium at 37 deg. C grow in hyphal form in aerobic conditions, but they grow in yeast form in anaerobic conditions. The hyphal growth of C. albicans was inhibited in glucose-deficient conditions. Malonic acid, an inhibitor of succinate dehydrogenase, enhanced the yeast proliferation of C. albicans, indicating that the hyphal-formation signal was derived from the glycolysis system and the signal was transmitted to the electron transfer system via the citric acid cycle. Thenoyl trifluoro acetone (TTFA), an inhibitor of the signal transmission between complex II and Co Q, significantly inhibited the hyphal growth of C. albicans. Antimycin, KCN, and oligomycin, inhibitors of complex III, IV, and V, respectively, did not inhibit the hyphal growth of C. albicans. The production of mRNAs for the hyphal formation signal was completely inhibited in anaerobic conditions. These results indicate that the electron transfer system functions upstream of the RAS1 signal pathway and activates the expression of the hyphal formation signal. Since the electron transfer system is inactivated in anaerobic conditions, C. albicans grew in yeast form in this condition.

  12. 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. PMID:24102473

  13. Antifungal Activity of Bee Venom and Sweet Bee Venom against Clinically Isolated Candida albicans

    PubMed Central

    Lee, Seung-Bae

    2016-01-01

    Objectives: The purpose of this study was to investigate the antifungal effect of bee venom (BV) and sweet bee venom (SBV) against Candida albicans (C. albicans) clinical isolates. Methods: In this study, BV and SBV were examined for antifungal activities against the Korean Collection for Type Cultures (KCTC) strain and 10 clinical isolates of C. albicans. The disk diffusion method was used to measure the antifungal activity and minimum inhibitory concentration (MIC) assays were performed by using a broth microdilution method. Also, a killing curve assay was conducted to investigate the kinetics of the anti- fungal action. Results: BV and SBV showed antifungal activity against 10 clinical isolates of C. albicans that were cultured from blood and the vagina by using disk diffusion method. The MIC values obtained for clinical isolates by using the broth microdilution method varied from 62.5 μg/ mL to 125 μg/mL for BV and from 15.63 μg/mL to 62.5 μg/mL for SBV. In the killing-curve assay, SBV behaved as amphotericin B, which was used as positive control, did. The antifungal efficacy of SBV was much higher than that of BV. Conclusion: BV and SBV showed antifungal activity against C. albicans clinical strains that were isolated from blood and the vagina. Especially, SBV might be a candidate for a new antifungal agent against C. albicans clinical isolates. PMID:27280049

  14. Candida albicans morphology and dendritic cell subsets determine T helper cell differentiation.

    PubMed

    Kashem, Sakeen W; Igyártó, Botond Z; Gerami-Nejad, Maryam; Kumamoto, Yosuke; Mohammed, Javed; Jarrett, Elizabeth; Drummond, Rebecca A; Zurawski, Sandra M; Zurawski, Gerard; Berman, Judith; Iwasaki, Akiko; Brown, Gordon D; Kaplan, Daniel H

    2015-02-17

    Candida albicans is a dimorphic fungus responsible for chronic mucocutaneous and systemic infections. Mucocutaneous immunity to C. albicans requires T helper 17 (Th17) cell differentiation that is thought to depend on recognition of filamentous C. albicans. Systemic immunity is considered T cell independent. Using a murine skin infection model, we compared T helper cell responses to yeast and filamentous C. albicans. We found that only yeast induced Th17 cell responses through a mechanism that required Dectin-1-mediated expression of interleukin-6 (IL-6) by Langerhans cells. Filamentous forms induced Th1 without Th17 cell responses due to the absence of Dectin-1 ligation. Notably, Th17 cell responses provided protection against cutaneous infection while Th1 cell responses provided protection against systemic infection. Thus, C. albicans morphology drives distinct T helper cell responses that provide tissue-specific protection. These findings provide insight into compartmentalization of Th cell responses and C. albicans pathogenesis and have critical implications for vaccine strategies. PMID:25680275

  15. Identification of the aminocatechol A-3253 as an in vitro poison of DNA topoisomerase I from Candida albicans.

    PubMed Central

    Fostel, J; Montgomery, D

    1995-01-01

    The aminocatechol A-3253 is active against several pathogenic fungi, including Candida albicans, Cryptococcus albidus, and Aspergillus niger. A-3253 interferes with both the in vitro biosynthesis of (1,3)-beta-glucan and the activity of topoisomerases I isolated from Candida spp. It is likely that one or more of the enzymes involved in glucan biosynthesis rather than topoisomerase I is the primary intracellular target of A-3253, since a strain of Saccharomyces cerevisiae lacking topoisomerase I is as susceptible to A-3253 as cells containing wild-type levels of topoisomerase I. However, the interaction of A-3253 with topoisomerase I in vitro is of interest since the Candida topoisomerase is more susceptible to A-3253 than is the topoisomerase I isolated from human HeLa cells. A-3253 is both a reversible inhibitor of topoisomerase I catalysis and a reversible poison of topoisomerase I, and in both reactions the fungal topoisomerase I is more susceptible than the human topoisomerase I to A-3253. In contrast, an earlier study found that the human topoisomerase I is more susceptible than the fungal topoisomerase to camptothecin (J. M. Fostel, D. A. Montgomery, and L. L. Shen, Antimicrob. Agents Chemother. 36:2131-2138, 1992). Taken together with the response to camptothecin, the greater susceptibility of the Candida topoisomerase I to A-3253 suggests that there are structural differences between the human and fungal type I topoisomerases which can likely be exploited to allow for the development of antifungal agents which act against the fungal topoisomerase and which have minimal activity against the human enzyme. PMID:7793856

  16. Candida albicans-Derived β-1,2-Linked Mannooligosaccharides Induce Desensitization of Macrophages

    PubMed Central

    Jouault, Thierry; Fradin, Chantal; Trinel, Pierre-André; Poulain, Daniel

    2000-01-01

    Candida albicans β-1,2-oligomannosides stimulate macrophage tumor necrosis factor alpha (TNF-α) but not NO release. This stimulation desensitized macrophages by altering β-1,2-oligomannoside-dependent TNF-α production and lipopolysaccharide-dependent TNF-α and NO secretion. Desensitization was not related to tyrosine phosphorylation signal transduction but was transferred by culture supernatants in which arachidonic acid derivatives were evidenced. PMID:10639473

  17. Ibuprofen Potentiates the In Vivo Antifungal Activity of Fluconazole against Candida albicans Murine Infection

    PubMed Central

    Miranda, Isabel M.; Silva-Dias, Ana; Silva, Ana P.; Rodrigues, Acácio G.; Pina-Vaz, Cidália

    2015-01-01

    Candida albicans is the most prevalent cause of fungemia worldwide. Its ability to develop resistance in patients receiving azole antifungal therapy is well documented. In a murine model of systemic infection, we show that ibuprofen potentiates fluconazole antifungal activity against a fluconazole-resistant strain, drastically reducing the fungal burden and morbidity. The therapeutic combination of fluconazole with ibuprofen may constitute a new approach for the management of antifungal therapeutics to reverse the resistance conferred by efflux pump overexpression. PMID:25845879

  18. Micafungin for Candida albicans pacemaker-associated endocarditis: a case report and review of the literature.

    PubMed

    Tascini, Carlo; Bongiorni, Maria Grazia; Tagliaferri, Enrico; Di Paolo, Antonello; Flammini, Sarah; Soldati, Ezio; Leonildi, Alessandro; Di Cori, Andrea; Menichetti, Francesco

    2013-02-01

    We report on the treatment with micafungin of a pacemaker-associated endocarditis due to Candida albicans. Antifungal therapy was able to reduce vegetation size from 5 to 1 cm making possible the transvenous removal of the device without a high risk of pulmonary embolism. Noteworthy, a high micafungin concentration was documented into the lead vegetation (10 μg/g of vegetation tissue) and this may have contributed to the striking size reduction of vegetation. PMID:23073824

  19. Effect of Delta-9-Tetrahydrocannabinol on Mouse Resistance to Systemic Candida albicans Infection

    PubMed Central

    Blumstein, Gideon W.; Parsa, Arya; Park, Anthony K.; McDowell, Beverly L. P.; Arroyo-Mendoza, Melissa; Girguis, Marie; Adler-Moore, Jill P.; Olson, Jon; Buckley, Nancy E.

    2014-01-01

    Delta-9-tetrahydrocannabinol (Δ9-THC), the psychoactive component of marijuana, is known to suppress the immune responses to bacterial, viral and protozoan infections, but its effects on fungal infections have not been studied. Therefore, we investigated the effects of chronic Δ9-THC treatment on mouse resistance to systemic Candida albicans (C. albicans) infection. To determine the outcome of chronic Δ9-THC treatment on primary, acute systemic candidiasis, c57BL/6 mice were given vehicle or Δ9-THC (16 mg/kg) in vehicle on days 1–4, 8–11 and 15–18. On day 19, mice were infected with 5×105 C. albicans. We also determined the effect of chronic Δ9-THC (4–64 mg/kg) treatment on mice infected with a non-lethal dose of 7.5×104 C. albicans on day 2, followed by a higher challenge with 5×105 C. albicans on day 19. Mouse resistance to the infection was assessed by survival and tissue fungal load. Serum cytokine levels were determine to evaluate the immune responses. In the acute infection, chronic Δ9-THC treatment had no effect on mouse survival or tissue fungal load when compared to vehicle treated mice. However, Δ9-THC significantly suppressed IL-12p70 and IL-12p40 as well as marginally suppressed IL-17 versus vehicle treated mice. In comparison, when mice were given a secondary yeast infection, Δ9-THC significantly decreased survival, increased tissue fungal burden and suppressed serum IFN-γ and IL-12p40 levels compared to vehicle treated mice. The data showed that chronic Δ9-THC treatment decreased the efficacy of the memory immune response to candida infection, which correlated with a decrease in IFN-γ that was only observed after the secondary candida challenge. PMID:25057822

  20. Inhibition of human natural killer (NK) cytotoxicity by Candida albicans

    SciTech Connect

    Zunino, S.; Hudig, D.

    1986-03-01

    Experiments were initiated to determine whether human NK cells are cytotoxic to C. albicans with similar activity observed for mouse NK cells against the yeast Paracoccidiodes brasiliensis. In 48 hour assays using limiting dilutions of C. albicans, strain 3153A, mononuclear leukocytes with NK activity had only marginal effects on yeast outgrowth, whereas granulocytes killed most of the yeast. However, these yeast were able to block NK activity in 4 hr /sup 51/Cr release assays with K562 cells, at yeast to K562 ratios of 10:1 and 100:1. Yeast pretreated with the serum of the majority of donors blocked the NK activity more than untreated yeast. Two of the 7 donors did not enhance NK inhibition after pretreatment of the yeast with their serum. Serum antibody to C. albicans and complement consumption by the yeast correlated with the relative efficiency of NK inhibition for most donors. This report suggests that there may be in vivo interactions between NK cells of the immune system and opportunistic fungal pathogens, which may compromise NK cell function.

  1. Manipulation of Host Diet To Reduce Gastrointestinal Colonization by the Opportunistic Pathogen Candida albicans

    PubMed Central

    Tornberg-Belanger, Stephanie N.; Matthan, Nirupa R.; Lichtenstein, Alice H.

    2015-01-01

    ABSTRACT 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 drugs prevents C. albicans-associated mortalities. C. albicans provides a clinically relevant system for studying the relationship between diet and the microbiota as it relates to commensalism and pathogenicity. As a first step toward a dietary intervention to reduce C. albicans GI colonization, we investigated the impact of dietary lipids on murine colonization by C. albicans. Coconut oil and its constituent fatty acids have antifungal activity in vitro; we hypothesized that dietary coconut oil would reduce GI colonization by C. albicans. Colonization was lower in mice fed a coconut oil-rich diet than in mice fed diets rich in beef tallow or soybean oil. Switching beef tallow-fed mice to a coconut oil diet reduced preexisting colonization. Coconut oil reduced colonization even when the diet also contained beef tallow. Dietary coconut oil also altered the metabolic program of colonizing C. albicans cells. Long-chain fatty acids were less abundant in the cecal contents of coconut oil-fed mice than in the cecal contents of beef tallow-fed mice; the expression of genes involved in fatty acid utilization was lower in C. albicans from coconut oil-fed mice than in C. albicans from beef tallow-fed mice. Extrapolating to humans, these findings suggest that coconut oil could become the first dietary intervention to reduce C. albicans GI colonization. IMPORTANCE Candida albicans, the most common human fungal pathogen, can cause infections with a mortality rate of ~40%. C. albicans is part of the normal gut flora, but when a patient’s immune system is compromised, it can leave the gut and cause infections. By reducing the amount of C. albicans in the gut of

  2. Manipulation of Host Diet To Reduce Gastrointestinal Colonization by the Opportunistic Pathogen Candida albicans.

    PubMed

    Gunsalus, Kearney T W; Tornberg-Belanger, Stephanie N; Matthan, Nirupa R; Lichtenstein, Alice H; Kumamoto, Carol A

    2016-01-01

    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 drugs prevents C. albicans-associated mortalities. C. albicans provides a clinically relevant system for studying the relationship between diet and the microbiota as it relates to commensalism and pathogenicity. As a first step toward a dietary intervention to reduce C. albicans GI colonization, we investigated the impact of dietary lipids on murine colonization by C. albicans. Coconut oil and its constituent fatty acids have antifungal activity in vitro; we hypothesized that dietary coconut oil would reduce GI colonization by C. albicans. Colonization was lower in mice fed a coconut oil-rich diet than in mice fed diets rich in beef tallow or soybean oil. Switching beef tallow-fed mice to a coconut oil diet reduced preexisting colonization. Coconut oil reduced colonization even when the diet also contained beef tallow. Dietary coconut oil also altered the metabolic program of colonizing C. albicans cells. Long-chain fatty acids were less abundant in the cecal contents of coconut oil-fed mice than in the cecal contents of beef tallow-fed mice; the expression of genes involved in fatty acid utilization was lower in C. albicans from coconut oil-fed mice than in C. albicans from beef tallow-fed mice. Extrapolating to humans, these findings suggest that coconut oil could become the first dietary intervention to reduce C. albicans GI colonization. IMPORTANCE Candida albicans, the most common human fungal pathogen, can cause infections with a mortality rate of ~40%. C. albicans is part of the normal gut flora, but when a patient's immune system is compromised, it can leave the gut and cause infections. By reducing the amount of C. albicans in the gut of susceptible

  3. In vitro effects of Salvia officinalis L. essential oil on Candida albicans

    PubMed Central

    Sookto, Tularat; Srithavaj, Theerathavaj; Thaweboon, Sroisiri; Thaweboon, Boonyanit; Shrestha, Binit

    2013-01-01

    Objective To determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface. Methods Disc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey's test was used for multiple comparisons. Results S. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05). Conclusions S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis. PMID:23646301

  4. Farnesol biosynthesis in Candida albicans: cellular response to sterol inhibition by zaragozic acid B.

    PubMed

    Hornby, Jacob M; Kebaara, Bessie W; Nickerson, Kenneth W

    2003-07-01

    The dimorphic fungus Candida albicans produces farnesol as a quorum-sensing molecule that regulates cellular morphology. The biosynthetic origin of farnesol has been resolved by treating these cells with zaragozic acid B, a potent inhibitor of squalene synthase in the sterol biosynthetic pathway. Treatment with zaragozic acid B leads to an eightfold increase in the amount of farnesol produced by C. albicans. Furthermore, C. albicans cell extracts contain enzymatic activity to convert [(3)H]farnesyl pyrophosphate to [(3)H]farnesol. Many common antifungal antibiotics (e.g., zaragozic acids, azoles, and allylamines) target steps in sterol biosynthesis. We suggest that the fungicidal activity of zaragozic acid derives in large part from the accumulation of farnesol that accompanies the inhibition of sterol biosynthesis. PMID:12821501

  5. Oral Immunization Against Candidiasis Using Lactobacillus casei Displaying Enolase 1 from Candida albicans

    PubMed Central

    Shibasaki, Seiji; Karasaki, Miki; Tafuku, Senji; Aoki, Wataru; Sewaki, Tomomitsu; Ueda, Mitsuyoshi

    2014-01-01

    Abstract Candidiasis is a common fungal infection that is prevalent in immunocompromised individuals. In this study, an oral vaccine against Candida albicans was developed by using the molecular display approach. Enolase 1 protein (Eno1p) of C. albicans was expressed on the Lactobacillus casei cell surface by using poly-gamma-glutamic acid synthetase complex A from Bacillus subtilis as an anchoring protein. The Eno1p-displaying L. casei cells were used to immunize mice, which were later challenged with a lethal dose of C. albicans. The data indicated that the vaccine elicited a strong IgG response and increased the survival rate of the vaccinated mice. Furthermore, L. casei acted as a potent adjuvant and induced high antibody titers that were comparable to those induced by strong adjuvants such as the cholera toxin. Overall, the molecular display method can be used to rapidly develop vaccines that can be conveniently administered and require minimal processing. PMID:25853077

  6. Modulation of Candida albicans attachment to human epithelial cells by bacteria and carbohydrates.

    PubMed Central

    Centeno, A; Davis, C P; Cohen, M S; Warren, M M

    1983-01-01

    The effects of carbohydrates (mannose and dextrose). Escherichia coli 07KL. and Klebsiella pneumoniae on Candida albicans attachment to epithelial cells was studied. Dextrose had no effect on yeast attachment to epithelial cells. Conversely, mannose significantly decreased both yeast and piliated bacterial attachment (E. coli 07KL, heavily piliated K. pneumoniae) whereas having no effect on nonpiliated K. pneumoniae attachment to epithelial cells. The number of yeasts attaching to epithelial cells was enhanced by preincubation of epithelial cells with piliated strains of bacteria, whereas preincubation with nonpiliated strains of bacteria had no effect on yeast attachment. Scanning electron microscopy showed that piliated bacteria and yeasts were juxtaposed on the epithelial cell surface. These data suggest that certain piliated strains of bacteria can enhance C. albicans attachment to epithelial cells and that type 1 pili of bacteria can be a factor in the enhanced attachment of C. albicans to epithelial cells. Images PMID:6132878

  7. The Role of Autophagy-Related Proteins in Candida albicans Infections.

    PubMed

    Tam, Jenny M; Mansour, Michael K; Acharya, Mridu; Sokolovska, Anna; Timmons, Allison K; Lacy-Hulbert, Adam; Vyas, Jatin M

    2016-01-01

    Autophagy plays an important role in maintaining cell homeostasis by providing nutrients during periods of starvation and removing damaged organelles from the cytoplasm. A marker in the autophagic process is the reversible conjugation of LC3, a membrane scaffolding protein, to double membrane autophagosomes. Recently, a role for LC3 in the elimination of pathogenic bacteria and fungi, including Candida albicans (C. albicans), was demonstrated, but these organisms reside in single membrane phagosomes. This process is distinct from autophagy and is termed LC3-associated phagocytosis (LAP). This review will detail the hallmarks of LAP that distinguish it from classical autophagy and review the role of autophagy proteins in host response to C. albicans and other pathogenic fungi. PMID:27043636

  8. Mice with persistent gastrointestinal Candida albicans as a model for antifungal therapy.

    PubMed Central

    Herrera, C; Guentzel, M N

    1982-01-01

    Persistent infection of the gastrointestinal tract of CFW mice with Candida albicans was produced by the oral-intragastric inoculation of 6-day-old infants. Other intraabdominal organs (liver, kidneys, and spleen) were usually free of the organism in survivors at 20 days of age. However, all survivors retained high levels of the organism in the stomach and intestinal tract at 30 days of age. The possible utility of these persisting C. albicans infections of the gastrointestinal tract for the study of the efficacy of short-term antifungal therapy was studied. Drug treatment was initiated for a 2-week period when the survivors were 15 to 19 days old. Some representative antifungal agents in current use (i.e., amphotericin B, 5-fluorocytosine, and miconazole) effected significant reductions in the numbers of C. albicans in homogenates of gastrointestinal organs. PMID:7044301

  9. Eugenol and thymol, alone or in combination, induce morphological alterations in the envelope of Candida albicans.

    PubMed

    Braga, P C; Sasso, M Dal; Culici, M; Alfieri, M

    2007-09-01

    The envelope of Candida albicans, with its outermost array of macromolecules protruding towards the environment, is pivotal to the expression of major virulence factors such as adhesiveness, and the morphological transition to hyphal form. We tested the anticandidal activity of eugenol, main component of clove oil, and thymol, main component of thyme oil, alone or in combination, by investigating their ability to interfere with the architecture of the envelope of C. albicans. Both molecules alterated the morphogenesis of the envelope, but the effects of thymol were more pronounced than those of eugenol. Certain combinations of the two molecules led to a synergistic effect, which is interesting in the view of potentiating their inhibition of C. albicans colonisation and infectiousness. PMID:17590533

  10. Novel Regulatory Mechanisms of Pathogenicity and Virulence to Combat MDR in Candida albicans

    PubMed Central

    Hameed, Saif; Fatima, Zeeshan

    2013-01-01

    Continuous deployment of antifungals in treating infections caused by dimorphic opportunistic pathogen Candida albicans has led to the emergence of drug resistance resulting in cross-resistance to many unrelated drugs, a phenomenon termed multidrug resistance (MDR). Despite the current understanding of major factors which contribute to MDR mechanisms, there are many lines of evidence suggesting that it is a complex interplay of multiple factors which may be contributed by still unknown mechanisms. Coincidentally with the increased usage of antifungal drugs, the number of reports for antifungal drug resistance has also increased which further highlights the need for understanding novel molecular mechanisms which can be explored to combat MDR, namely, ROS, iron, hypoxia, lipids, morphogenesis, and transcriptional and signaling networks. Considering the worrying evolution of MDR and significance of C. albicans being the most prevalent human fungal pathogen, this review summarizes these new regulatory mechanisms which could be exploited to prevent MDR development in C. albicans as established from recent studies. PMID:24163696

  11. Effect of ferrocene-substituted porphyrin RL-91 on Candida albicans biofilm formation.

    PubMed

    Lippert, Rainer; Vojnovic, Sandra; Mitrovic, Aleksandra; Jux, Norbert; Ivanović-Burmazović, Ivana; Vasiljevic, Branka; Stankovic, Nada

    2014-08-01

    Ferrocene-substituted porphyrin RL-91 exhibits antifungal activity against opportune human pathogen Candida albicans. RL-91 efficiently inhibits growth of both planktonic C. albicans cells and cells within biofilms without photoactivation. The minimal inhibitory concentration for plankton form (PMIC) was established to be 100 μg/mL and the same concentration killed 80% of sessile cells in the mature biofilm (SMIC80). Furthermore PMIC of RL-91 efficiently prevents C. albicans biofilm formation. RL-91 is cytotoxic for human fibroblasts in vitro in concentration of 10 μg/mL, however it does not cause hemolysis in concentrations of up to 50 μg/mL. These findings open possibility for application of RL-91 as an antifungal agent for external antibiofilm treatment of medical devices as well as a scaffold for further development of porphyrin based systemic antifungals. PMID:24929472

  12. Artemisinins, new miconazole potentiators resulting in increased activity against Candida albicans biofilms.

    PubMed

    De Cremer, Kaat; Lanckacker, Ellen; Cools, Tanne L; Bax, Marijke; De Brucker, Katrijn; Cos, Paul; Cammue, Bruno P A; Thevissen, Karin

    2015-01-01

    Mucosal biofilm-related fungal infections are very common, and the incidence of recurrent oral and vulvovaginal candidiasis is significant. As resistance to azoles (the preferred treatment) is occurring, we aimed at identifying compounds that increase the activity of miconazole against Candida albicans biofilms. We screened 1,600 compounds of a drug-repositioning library in combination with a subinhibitory concentration of miconazole. Synergy between the best identified potentiators and miconazole was characterized by checkerboard analyses and fractional inhibitory concentration indices. Hexachlorophene, pyrvinium pamoate, and artesunate act synergistically with miconazole in affecting C. albicans biofilms. Synergy was most pronounced for artesunate and structural homologues thereof. No synergistic effect could be observed between artesunate and fluconazole, caspofungin, or amphotericin B. Our data reveal enhancement of the antibiofilm activity of miconazole by artesunate, pointing to potential combination therapy consisting of miconazole and artesunate to treat C. albicans biofilm-related infections. PMID:25367916

  13. In vitro effects of glycyrrhetinic acid on the growth of clinical isolates of Candida albicans.

    PubMed

    Pellati, Donatella; Fiore, Cristina; Armanini, Decio; Rassu, Mario; Bertoloni, Giulio

    2009-04-01

    Compounds derived from Glycyrrhiza glabra L. root have been used widely for centuries for their numerous therapeutic properties. The present study aimed to test the in vitro activity against Candida albicans strains of the compound 18-beta glycyrrhetinic acid (18-beta GA), derived from the root of Glycyrrhiza species. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS) method on C. albicans strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC). The in vitro growth of the C. albicans strains was markedly reduced, in a pH-dependent manner, by relatively low doses (6.2 microg/mL) of 18-beta GA. The results demonstrate that 18-beta GA is a promising biological alternative for the topical treatment of recurrent vulvovaginal candidiasis (RVVC). PMID:19067381

  14. The Role of Autophagy-Related Proteins in Candida albicans Infections

    PubMed Central

    Tam, Jenny M.; Mansour, Michael K.; Acharya, Mridu; Sokolovska, Anna; Timmons, Allison K.; Lacy-Hulbert, Adam; Vyas, Jatin M.

    2016-01-01

    Autophagy plays an important role in maintaining cell homeostasis by providing nutrients during periods of starvation and removing damaged organelles from the cytoplasm. A marker in the autophagic process is the reversible conjugation of LC3, a membrane scaffolding protein, to double membrane autophagosomes. Recently, a role for LC3 in the elimination of pathogenic bacteria and fungi, including Candida albicans (C. albicans), was demonstrated, but these organisms reside in single membrane phagosomes. This process is distinct from autophagy and is termed LC3-associated phagocytosis (LAP). This review will detail the hallmarks of LAP that distinguish it from classical autophagy and review the role of autophagy proteins in host response to C. albicans and other pathogenic fungi. PMID:27043636

  15. Oral Immunization Against Candidiasis Using Lactobacillus casei Displaying Enolase 1 from Candida albicans.

    PubMed

    Shibasaki, Seiji; Karasaki, Miki; Tafuku, Senji; Aoki, Wataru; Sewaki, Tomomitsu; Ueda, Mitsuyoshi

    2014-09-01

    Candidiasis is a common fungal infection that is prevalent in immunocompromised individuals. In this study, an oral vaccine against Candida albicans was developed by using the molecular display approach. Enolase 1 protein (Eno1p) of C. albicans was expressed on the Lactobacillus casei cell surface by using poly-gamma-glutamic acid synthetase complex A from Bacillus subtilis as an anchoring protein. The Eno1p-displaying L. casei cells were used to immunize mice, which were later challenged with a lethal dose of C. albicans. The data indicated that the vaccine elicited a strong IgG response and increased the survival rate of the vaccinated mice. Furthermore, L. casei acted as a potent adjuvant and induced high antibody titers that were comparable to those induced by strong adjuvants such as the cholera toxin. Overall, the molecular display method can be used to rapidly develop vaccines that can be conveniently administered and require minimal processing. PMID:25853077

  16. Comparison of Antifungal Activity of 2% Chlorhexidine, Calcium Hydroxide, and Nanosilver gels against Candida Albicans

    PubMed Central

    Mozayeni, Mohammad Ali; Hadian, Ali; Bakhshaei, Pedram; Dianat, Omid

    2015-01-01

    Objectives: Residual microorganisms in the root canal system (RCS) after endodontic therapy such as Candida albicans are a major cause of endodontic failure. Calcium hydroxide (CH) and chlorhexidine (CHX) have suitable antimicrobial activity against bacteria and can be used as intracanal medicaments. Nanosilver has also shown antimicrobial activity against microorganisms. This study aimed to compare the antifungal effect of calcium hydroxide, 2% chlorhexidine and nanosilver gels on Candida albicans. Materials and Methods: Eighty-one single-rooted teeth were selected. After root canal preparation, the teeth were contaminated. After culture, the teeth were randomly divided into 4 groups. In experimental groups, 24 teeth were selected and completely filled with CH, 2% CHX and nanosilver gels in each group. Nine teeth were selected in the control group and filled with saline solution. After 1, 3, and 7 days, samples were obtained by #30 sterile paper points, and #2 and #4 Gates Glidden drills and cultured on solid Sabouraud agar. Results: The results demonstrated that CH and 2% CHX had equal antifungal effects on samples taken by paper point and #2 Gates Glidden drill at all time points. Both CH and 2% CHX were more effective than nanosilver at all time periods. There was no statistically significant difference between medicaments in samples taken by #4 Gates Glidden drill. Conclusion: CH and 2% CHX gels have significantly higher antifungal activity than nanosilver gel. Also, CH and 2% CHX gels are equally effective against Candida albicans. PMID:26056520

  17. DLH1 is a functional Candida albicans homologue of the meiosis-specific gene DMC1

    SciTech Connect

    Diener, A.C.; Fink, G.R.

    1996-06-01

    DMC1/LIM15 homologue 1 (DLH1), a gene related to meiosis-specific genes, has been isolated from Candida albicans, a fungus thought not to undergo meiosis. The deduced protein sequence of DLH1 contains 74% amino acid identity with Dmc1p from Saccharomyces cerevisiae and 63% with Lim15p from the plant Lilium longiflorum, meiosis-specific homologous of Escherichia coli RecA. Candida DLH1 complements a dmc1/dmc1 null mutant in S. cerevisiae. High copy expression of DLH1 restores both sporulation and meiotic recombination to a Saccharomyces dmc1/{Delta}/dmc1{Delta} strain. Unlike the DMC1 gene, which is transcribed only in meiotic cells, the heterologous Candida DLH1 gene is transcribed in both vegetative and meiotic cells of S. cerevisiae. Transcription of DLH1 is not detected or induced in C. albicans under conditions that induce DMC1 and meiosis in S. cerevisiae. The presence of an intact homologue of a meiosis-specific gene in C. albicans raises the possibility that this organism has a cryptic meiotic pathway. 25 refs., 6 figs., 3 tabs.

  18. The effect of thyme and tea tree oils on morphology and metabolism of Candida albicans.

    PubMed

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

    2014-01-01

    Members of Candida species cause significant problems in medicine and in many industrial branches also. In order to prevent from Candida sp. development, essential oils are more and more frequently applied as natural, non-toxic, non-pollutive and biodegradable agents with a broad spectrum of antimicrobial activity. The aim of the research was to determine changes in morphology and metabolic properties of Candida albicans in the presence of thyme and tea tree oils. Changes of enzymatic activity of isolates were observed in the presence of both tested essential oils, and they were primarily associated with loss or decrease of activity of all enzymes detected for control. Furthermore, only for 3 out of 11 isolates additional activity of N-acetyl-β-glucosaminidase, α-mannosidase, α-fucosidase and trypsin was detected. Vivid changes in biochemical profiles were found after treatment with tea tree oil and they were related to loss of ability to assimilate D-xylose, D-sorbitol and D-trehalose. The main differences in morphology of isolates compared to the control strain concerned formation of pseudohyphae structures. Both examined essential oils caused changes in cell and colony morphology, as well as in the metabolism of Candida albicans. However, the extent of differences depends on the type and concentration of an essential oil. The most important finding is the broad spectrum of changes in yeast enzymatic profiles induced by thyme and tea tree oils. It can be supposed that these changes, together with loss of ability to assimilate saccharides could significantly impact Candida albicans pathogenicity. PMID:24918492

  19. Possible Inhibitory Molecular Mechanism of Farnesol on the Development of Fluconazole Resistance in Candida albicans Biofilm

    PubMed Central

    Yu, Li-hua; Ma, Ming; Chen, Xiao-jun; Xu, Shuang-bo

    2012-01-01

    Candida albicans biofilm infections are usually treated with azole antifungals such as fluconazole. However, the development of resistance to this drug in C. albicans biofilms is very common, especially in immunocompromised individuals. The upregulation of the sterol biosynthetic pathway gene ERG and the efflux pump genes CDR and MDR may contribute to this azole tolerance in Candida species. We hypothesize that farnesol, an endogenous quorum sensing molecule with possible antimicrobial properties which is also the precursor of ergosterols in C. albicans, may interfere with the development of fluconazole resistance in C. albicans biofilms. To test this hypothesis, MICs were compared and morphology changes were observed by confocal laser scanning microscopy (CLSM) for farnesol-treated and -untreated and fluconazole-resistant groups. The expression of possible target genes (ERG11, ERG25, ERG6, ERG5, ERG3, ERG1, MDR1, CDR1, and CDR2) in biofilms was analyzed by reverse transcription-PCR (RT-PCR) and quantitative PCR (qPCR) to investigate the molecular mechanisms of the inhibitory effects of farnesol. The results showed a decreased MIC of fluconazole and thinner biofilms for the farnesol-treated group, indicating that farnesol inhibited the development of fluconazole resistance. The sterol biosynthetic pathway may contribute to the inhibitory effects of farnesol, as the transcription levels of the ERG11, ERG25, ERG6, ERG3, and ERG1 genes decreased in the farnesol-treated group. PMID:22106223

  20. Effect of two monoterpene phenols on antioxidant defense system in Candida albicans.

    PubMed

    Khan, Amber; Ahmad, Aijaz; Ahmad Khan, Luqman; Padoa, Carolyn J; van Vuuren, Sandy; Manzoor, Nikhat

    2015-03-01

    Thymol and carvacrol from the class of monoterpene phenols are one of the most potent plant essential oil components possessing antimicrobial effects. Known for their wide bioactive spectrum, these positional isomers of isopropyl cresol deplete ergosterol content, compromise membrane permeability, block efflux pumps and restore antifungal susceptibility to fluconazole in resistant Candida strains. Exposure to these natural compounds induces a cascade of stress responses, which are important to comprehend their microbicidal mechanisms. This study evaluates the antioxidant defense response to lower concentrations of thymol and carvacrol in Candida albicans. The antioxidant defense responses in C. albicans are important for developmental mechanisms pertaining to resistance against the immune system, infection establishment and drug resistance. In this view, primary and secondary antioxidant defense enzymes, and oxidative stress markers including glutathione and lipid peroxidation were determined in C. albicans cells exposed to lower concentrations of thymol and carvacrol. These compounds were found to induce oxidative stress and compromised the antioxidant defense system in C. albicans at lower concentrations. This study helps in understanding the 'in cell' antifungal mechanisms of natural monoterpene phenols originating from oxidative stress. Thymol and carvacrol induced membrane deterioration reported earlier, is further explained as a result of a toxic radical cascade mediated by lipid peroxidation. Findings reinforce the observed toxic oxidizing effects of these compounds as a consequence of direct damage to antioxidant components and not to their genetic manipulations. PMID:25681060

  1. Top-down characterization data on the speciation of the Candida albicans immunome in candidemia

    PubMed Central

    Pitarch, Aida; Nombela, César; Gil, Concha

    2015-01-01

    The characterization of pathogen-specific antigenic proteins at the protein species level is crucial in the development and molecular optimization of novel immunodiagnostics, vaccines or immunotherapeutics for infectious diseases. The major requirements to achieve this molecular level are to obtain 100% sequence coverage and identify all post-translational modifications of each antigenic protein species. In this article, we show nearly complete sequence information for five discrete antigenic species of Candida albicans Tdh3 (glyceraldehyde-3-phosphate dehydrogenase), which have been reported to be differentially recognized both among candidemia patients and between candidemia and control patients. A comprehensive description of the top-down immunoproteomic strategy used for seroprofiling at the C. albicans protein species level in candidemia as well as for the chemical characterization of this immunogenic protein (based on high-resolution 2-DE, Western blotting, peptide mass fingerprinting, tandem mass spectrometry and de novo peptide sequencing) is also provided. The top-down characterization data on the speciation of the C. albicans immunome in candidemia presented here are related to our research article entitled “Seroprofiling at the Candida albicans protein species level unveils an accurate molecular discriminator for candidemia” (Pitarch et al., J. Proteomics, 2015, http://dx.doi.org/10.1016/j.jprot.2015.10.022). PMID:26862568

  2. Possible inhibitory molecular mechanism of farnesol on the development of fluconazole resistance in Candida albicans biofilm.

    PubMed

    Yu, Li-Hua; Wei, Xin; Ma, Ming; Chen, Xiao-Jun; Xu, Shuang-Bo

    2012-02-01

    Candida albicans biofilm infections are usually treated with azole antifungals such as fluconazole. However, the development of resistance to this drug in C. albicans biofilms is very common, especially in immunocompromised individuals. The upregulation of the sterol biosynthetic pathway gene ERG and the efflux pump genes CDR and MDR may contribute to this azole tolerance in Candida species. We hypothesize that farnesol, an endogenous quorum sensing molecule with possible antimicrobial properties which is also the precursor of ergosterols in C. albicans, may interfere with the development of fluconazole resistance in C. albicans biofilms. To test this hypothesis, MICs were compared and morphology changes were observed by confocal laser scanning microscopy (CLSM) for farnesol-treated and -untreated and fluconazole-resistant groups. The expression of possible target genes (ERG11, ERG25, ERG6, ERG5, ERG3, ERG1, MDR1, CDR1, and CDR2) in biofilms was analyzed by reverse transcription-PCR (RT-PCR) and quantitative PCR (qPCR) to investigate the molecular mechanisms of the inhibitory effects of farnesol. The results showed a decreased MIC of fluconazole and thinner biofilms for the farnesol-treated group, indicating that farnesol inhibited the development of fluconazole resistance. The sterol biosynthetic pathway may contribute to the inhibitory effects of farnesol, as the transcription levels of the ERG11, ERG25, ERG6, ERG3, and ERG1 genes decreased in the farnesol-treated group. PMID:22106223

  3. Application of surface plasmon resonance biosensor for the detection of Candida albicans

    NASA Astrophysics Data System (ADS)

    Yodmongkol, Sirasa; Thaweboon, Sroisiri; Thaweboon, Boonyanit; Puttharugsa, Chokchai; Sutapun, Boonsong; Amarit, Ratthasart; Somboonkaew, Armote; Srikhirin, Toemsak

    2016-02-01

    In this study, surface plasmon resonance imaging (SPR imaging) was developed for the detection of Candida albicans which is a causal agent of oral infection. The detection was based on the sandwich assay. The capture antibody was covalently immobilized on the mixed self assemble monolayers (SAMs). The ratio of mixed SAMs between 11-mercaptoundecanoic acid and 3-mercaptopropanol was varied to find the optimal ratio for use as a sensor surface. The results showed that the suitable surface for C. albicans detection was SAM of carboxylic (mixed SAMs 1:0), even though mixed SAMs 1:40 had a high detection signal in comparison to mixed SAMs 1:0, but the non-specific signal was higher. The detection limit was 107 cells/ml for direct detection, and was increased to 106 cells/ml with sandwich antibody. The use of polyclonal C. albicans antibody as capture and sandwich antibody showed good selectivity against the relevant oral bacteria including Escherichia coli, Streptococcus mutan, Staphylococcus aureus, β-streptococci, and Lactobacillus casei. SPR platform in this study could detect C. albicans from the mixed microbial suspension without requirement of skillful technician. This SPR imaging biosensor could be applied for Candida identification after cultivation.

  4. Nanoscopic cell-wall architecture of an immunogenic ligand in Candida albicans during antifungal drug treatment

    PubMed Central

    Lin, Jia; Wester, Michael J.; Graus, Matthew S.; Lidke, Keith A.; Neumann, Aaron K.

    2016-01-01

    The cell wall of Candida albicans is composed largely of polysaccharides. Here we focus on β-glucan, an immunogenic cell-wall polysaccharide whose surface exposure is often restricted, or “masked,” from immune recognition by Dectin-1 on dendritic cells (DCs) and other innate immune cells. Previous research suggested that the physical presentation geometry of β-glucan might determine whether it can be recognized by Dectin-1. We used direct stochastic optical reconstruction microscopy to explore the fine structure of β-glucan exposed on C. albicans cell walls before and after treatment with the antimycotic drug caspofungin, which alters glucan exposure. Most surface-accessible glucan on C. albicans yeast and hyphae is limited to isolated Dectin-1–binding sites. Caspofungin-induced unmasking caused approximately fourfold to sevenfold increase in total glucan exposure, accompanied by increased phagocytosis efficiency of DCs for unmasked yeasts. Nanoscopic imaging of caspofungin-unmasked C. albicans cell walls revealed that the increase in glucan exposure is due to increased density of glucan exposures and increased multiglucan exposure sizes. These findings reveal that glucan exhibits significant nanostructure, which is a previously unknown physical component of the host–Candida interaction that might change during antifungal chemotherapy and affect innate immune activation. PMID:26792838

  5. Top-down characterization data on the speciation of the Candida albicans immunome in candidemia.

    PubMed

    Pitarch, Aida; Nombela, César; Gil, Concha

    2016-03-01

    The characterization of pathogen-specific antigenic proteins at the protein species level is crucial in the development and molecular optimization of novel immunodiagnostics, vaccines or immunotherapeutics for infectious diseases. The major requirements to achieve this molecular level are to obtain 100% sequence coverage and identify all post-translational modifications of each antigenic protein species. In this article, we show nearly complete sequence information for five discrete antigenic species of Candida albicans Tdh3 (glyceraldehyde-3-phosphate dehydrogenase), which have been reported to be differentially recognized both among candidemia patients and between candidemia and control patients. A comprehensive description of the top-down immunoproteomic strategy used for seroprofiling at the C. albicans protein species level in candidemia as well as for the chemical characterization of this immunogenic protein (based on high-resolution 2-DE, Western blotting, peptide mass fingerprinting, tandem mass spectrometry and de novo peptide sequencing) is also provided. The top-down characterization data on the speciation of the C. albicans immunome in candidemia presented here are related to our research article entitled "Seroprofiling at the Candida albicans protein species level unveils an accurate molecular discriminator for candidemia" (Pitarch et al., J. Proteomics, 2015, http://dx.doi.org/10.1016/j.jprot.2015.10.022). PMID:26862568

  6. Candida albicans Hypha Formation and Mannan Masking of β-Glucan Inhibit Macrophage Phagosome Maturation

    PubMed Central

    Louw, Johanna; Lewis, Leanne E.; Okai, Blessing; Walls, Catriona A.; Ballou, Elizabeth R.; Walker, Louise A.; Reid, Delyth; Munro, Carol A.; Brown, Alistair J. P.; Brown, Gordon D.; Gow, Neil A. R.; Erwig, Lars P.

    2014-01-01

    ABSTRACT Candida albicans is a major life-threatening human fungal pathogen in the immunocompromised host. Host defense against systemic Candida infection relies heavily on the capacity of professional phagocytes of the innate immune system to ingest and destroy fungal cells. A number of pathogens, including C. albicans, have evolved mechanisms that attenuate the efficiency of phagosome-mediated inactivation, promoting their survival and replication within the host. Here we visualize host-pathogen interactions using live-cell imaging and show that viable, but not heat- or UV-killed C. albicans cells profoundly delay phagosome maturation in macrophage cell lines and primary macrophages. The ability of C. albicans to delay phagosome maturation is dependent on cell wall composition and fungal morphology. Loss of cell wall O-mannan is associated with enhanced acquisition of phagosome maturation markers, distinct changes in Rab GTPase acquisition by the maturing phagosome, impaired hyphal growth within macrophage phagosomes, profound changes in macrophage actin dynamics, and ultimately a reduced ability of fungal cells to escape from macrophage phagosomes. The loss of cell wall O-mannan leads to exposure of β-glucan in the inner cell wall, facilitating recognition by Dectin-1, which is associated with enhanced phagosome maturation. PMID:25467440

  7. Structure and regulation of the HSP90 gene from the pathogenic fungus Candida albicans.

    PubMed Central

    Swoboda, R K; Bertram, G; Budge, S; Gooday, G W; Gow, N A; Brown, A J

    1995-01-01

    Candida albicans HSP90 sequences were isolated by screening cDNA and genomic libraries with a probe derived from the Saccharomyces cerevisiae homolog, HSP82, which encodes a member of the heat shock protein 90 family of molecular chaperones. Identical sequences were obtained for the 2,197-bp overlap of the cDNA and gene sequences, which were derived from C. albicans 3153A and ATCC 10261, respectively. The C. albicans HSP90 gene contained no introns, and it showed strong homology (61 to 79% identity) to HSP90 sequences from other fungi, vertebrates, and plants. The C-terminal portion of the predicted Hsp90 amino acid sequence was identical to the 47-kDa protein which is thought to be immunoprotective during C. albicans infections (R. C. Matthews, J. Med. Microbiol. 36:367-370, 1992), confirming that this protein represents the C-terminal portion of the 81-kDa Hsp90 protein. Quantitative Northern (RNA) analyses revealed that C. albicans HSP90 mRNA was heat shock inducible and that its levels changed during batch growth, with its maximum levels being reached during the mid-exponential growth phase. HSP90 mRNA levels increased transiently during the yeast-to-hyphal transition but did not correlate directly with germ tube production per se. These data do not exclude a role for Hsp90 in the dimorphic transition. Southern blotting revealed only one HSP90 locus in the diploid C. albicans genome. Repeated attempts to disrupt both alleles and generate a homozygous C. albicans delta hsp90/delta hsp90 null mutant were unsuccessful. These observations suggest the existence of a single HSP90 locus which is essential for viability in C. albicans. PMID:7591093

  8. O-Mannosylation in Candida albicans Enables Development of Interkingdom Biofilm Communities

    PubMed Central

    Dutton, Lindsay C.; Nobbs, Angela H.; Jepson, Katy; Jepson, Mark A.; Vickerman, M. Margaret; Aqeel Alawfi, Sami; Munro, Carol A.; Lamont, Richard J.; Jenkinson, Howard F.

    2014-01-01

    ABSTRACT Candida albicans is a fungus that colonizes oral cavity surfaces, the gut, and the genital tract. Streptococcus gordonii is a ubiquitous oral bacterium that has been shown to form biofilm communities with C. albicans. Formation of dual-species S. gordonii-C. albicans biofilm communities involves interaction of the S. gordonii SspB protein with the Als3 protein on the hyphal filament surface of C. albicans. Mannoproteins comprise a major component of the C. albicans cell wall, and in this study we sought to determine if mannosylation in cell wall biogenesis of C. albicans was necessary for hyphal adhesin functions associated with interkingdom biofilm development. A C. albicans mnt1Δ mnt2Δ mutant, with deleted α-1,2-mannosyltransferase genes and thus defective in O-mannosylation, was abrogated in biofilm formation under various growth conditions and produced hyphal filaments that were not recognized by S. gordonii. Cell wall proteomes of hypha-forming mnt1Δ mnt2Δ mutant cells showed growth medium-dependent alterations, compared to findings for the wild type, in a range of protein components, including Als1, Als3, Rbt1, Scw1, and Sap9. Hyphal filaments formed by mnt1Δ mnt2Δ mutant cells, unlike wild-type hyphae, did not interact with C. albicans Als3 or Hwp1 partner cell wall proteins or with S. gordonii SspB partner adhesin, suggesting defective functionality of adhesins on the mnt1Δ mnt2Δ mutant. These observations imply that early stage O-mannosylation is critical for activation of hyphal adhesin functions required for biofilm formation, recognition by bacteria such as S. gordonii, and microbial community development. PMID:24736223

  9. The Effect of Essential Oils and Bioactive Fractions on Streptococcus mutans and Candida albicans Biofilms: A Confocal Analysis.

    PubMed

    Freires, Irlan Almeida; Bueno-Silva, Bruno; Galvão, Lívia Câmara de Carvalho; Duarte, Marta Cristina Teixeira; Sartoratto, Adilson; Figueira, Glyn Mara; de Alencar, Severino Matias; Rosalen, Pedro Luiz

    2015-01-01

    The essential oils (EO) and bioactive fractions (BF) from Aloysia gratissima, Baccharis dracunculifolia, Coriandrum sativum, Cyperus articulatus, and Lippia sidoides were proven to have strong antimicrobial activity on planktonic microorganisms; however, little is known about their effects on the morphology or viability of oral biofilms. Previously, we determined the EO/fractions with the best antimicrobial activity against Streptococcus mutans and Candida spp. In this report, we used a confocal analysis to investigate the effect of these EO and BF on the morphology of S. mutans biofilms (thickness, biovolume, and architecture) and on the metabolic viability of C. albicans biofilms. The analysis of intact treated S. mutans biofilms showed no statistical difference for thickness in all groups compared to the control. However, a significant reduction in the biovolume of extracellular polysaccharides and bacteria was observed for A. gratissima and L. sidoides groups, indicating that these BF disrupt biofilm integrity and may have created porosity in the biofilm. This phenomenon could potentially result in a weakened structure and affect biofilm dynamics. Finally, C. sativum EO drastically affected C. albicans viability when compared to the control. These results highlight the promising antimicrobial activity of these plant species and support future translational research on the treatment of dental caries and oral candidiasis. PMID:25821503

  10. The Effect of Essential Oils and Bioactive Fractions on Streptococcus mutans and Candida albicans Biofilms: A Confocal Analysis

    PubMed Central

    Freires, Irlan Almeida; Bueno-Silva, Bruno; Galvão, Lívia Câmara de Carvalho; Duarte, Marta Cristina Teixeira; Sartoratto, Adilson; Figueira, Glyn Mara; de Alencar, Severino Matias; Rosalen, Pedro Luiz

    2015-01-01

    The essential oils (EO) and bioactive fractions (BF) from Aloysia gratissima, Baccharis dracunculifolia, Coriandrum sativum, Cyperus articulatus, and Lippia sidoides were proven to have strong antimicrobial activity on planktonic microorganisms; however, little is known about their effects on the morphology or viability of oral biofilms. Previously, we determined the EO/fractions with the best antimicrobial activity against Streptococcus mutans and Candida spp. In this report, we used a confocal analysis to investigate the effect of these EO and BF on the morphology of S. mutans biofilms (thickness, biovolume, and architecture) and on the metabolic viability of C. albicans biofilms. The analysis of intact treated S. mutans biofilms showed no statistical difference for thickness in all groups compared to the control. However, a significant reduction in the biovolume of extracellular polysaccharides and bacteria was observed for A. gratissima and L. sidoides groups, indicating that these BF disrupt biofilm integrity and may have created porosity in the biofilm. This phenomenon could potentially result in a weakened structure and affect biofilm dynamics. Finally, C. sativum EO drastically affected C. albicans viability when compared to the control. These results highlight the promising antimicrobial activity of these plant species and support future translational research on the treatment of dental caries and oral candidiasis. PMID:25821503

  11. Sensitization of Candida albicans biofilms to fluconazole by terpenoids of plant origin.

    PubMed

    Doke, Sonali Kashinath; Raut, Jayant Shankar; Dhawale, Shashikant; Karuppayil, Sankunny Mohan

    2014-01-01

    Infections associated with the biofilms of Candida albicans are a challenge to antifungal treatment. Combinatorial therapy involving plant molecules with antifungal drugs would be an effective complementary approach against drug-resistant Candida biofilms. The aim of this study was to evaluate the efficacy of three bioactive terpenoids (carvacrol, eugenol and thymol) in combination with fluconazole against planktonic cells, biofilm development and mature biofilms of C. albicans. Activities of the selected molecules were tested using a microplate-based methodology, while their combinations with fluconazole were performed in a checkerboard format. Biofilms were quantitated by XTT-metabolic assay and confirmed by microscopic observations. Combinations of carvacrol and eugenol with fluconazole were found synergistic against planktonic growth of C. albicans, while that of thymol with fluconazole did not have any interaction. Biofilm development and mature biofilms were highly resistant to fluconazole, but susceptible to three terpenoids. Sensitization of cells by sub-inhibitory concentrations of carvacrol and eugenol resulted in prevention of biofilm formation at low fluconazole concentrations, i.e. 0.032 and 0.002 mg ml(-1), respectively. Addition of thymol could not potentiate activity of fluconazole against biofilm formation by C. albicans. Fractional inhibitory concentration indices (FICI) for carvacrol-fluconazole and eugenol-fluconazole combinations for biofilm formation were 0.311 and 0.25, respectively. The FICI value of 1.003 indicated a status of indifference for the combination of thymol and fluconazole against biofilm formation. Eugenol and thymol combinations with fluconazole did not have useful interaction against mature biofilms of C. albicans, but the presence of 0.5 mg ml(-1) of carvacrol caused inhibition of mature biofilms at a significantly low concentration (i.e. 0.032 mg ml(-1)) of fluconazole. The study indicated that carvacrol and eugenol

  12. Human submandibular-sublingual saliva promotes adhesion of Candida albicans to polymethylmethacrylate.

    PubMed Central

    Edgerton, M; Scannapieco, F A; Reddy, M S; Levine, M J

    1993-01-01

    The purpose of this study was to identify components of saliva that interact with Candida albicans in solution and that may modulate adhesion to dental acrylic (polymethylmethacrylate [PMMA]) surfaces. Saliva-derived pellicles extracted from C. albicans blastoconidia and hyphal-form cells mixed with fresh human submandibular-sublingual saliva (HSMSL) contained predominantly high- and low-molecular-weight mucins (MG1 and MG2, respectively). In contrast, few components from fresh human parotid saliva were adsorbed to yeast cells. Coating PMMA beads with HSMSL significantly enhanced (10-fold) adhesion of both growth forms of C. albicans compared with human parotid saliva (2-fold), suggesting a role for mucins in adhesion. HSMSL-enhanced adhesion was completely abolished by preadsorbing HSMSL with either blastoconidia or hyphal-form cells prior to coating PMMA. However, coating PMMA with purified salivary mucins or the addition of mucin to preadsorbed saliva did not enhance or restore adhesion to levels found with fresh HSMSL. Adhesion assays employing guanidine-treated fresh HSMSL showed a complete lack of Candida binding, suggesting that subjecting HSMSL to dissociating conditions may alter a property of salivary mucins crucial for C. albicans adhesion. Protease and glycosidase treatment of yeast cells significantly reduced adhesion to HSMSL-coated PMMA. In addition, preincubation of C. albicans with mannose and galactose inhibited adhesion to HSMSL-coated PMMA. These results suggest that mucins may play a role in C. albicans adhesion to saliva-coated PMMA and that a glycoprotein on the yeast surface may be involved in these events. Images PMID:8500903

  13. Dithiocarbamates are strong inhibitors of the beta-class fungal carbonic anhydrases from Cryptococcus neoformans, Candida albicans and Candida glabrata.

    PubMed

    Monti, Simona Maria; Maresca, Alfonso; Viparelli, Francesca; Carta, Fabrizio; De Simone, Giuseppina; Mühlschlegel, Fritz A; Scozzafava, Andrea; Supuran, Claudiu T

    2012-01-15

    A series of N-mono- and N,N-disubstituted dithiocarbamates have been investigated as inhibitors of three β-carbonic anhydrases (CAs, EC 4.2.1.1) from the fungal pathogens Cryptococcus neoformans, Candida albicans and Candida glabrata, that is, Can2, CaNce103 and CgNce103, respectively. These enzymes were inhibited with efficacies between the subnanomolar to the micromolar range, depending on the substitution pattern at the nitrogen atom from the dithiocarbamate zinc-binding group. This new class of β-CA inhibitors may have the potential for developing antifungal agents with a diverse mechanism of action compared to the clinically used drugs for which drug resistance was reported, and may also explain the efficacy of dithiocarbamates as agricultural antifungal agents. PMID:22209456

  14. Budding off: bringing functional genomics to Candida albicans.

    PubMed

    Anderson, Matthew Z; Bennett, Richard J

    2016-03-01

    Candidaspecies are the most prevalent human fungal pathogens, withCandida albicansbeing the most clinically relevant species.Candida albicansresides as a commensal of the human gastrointestinal tract but is a frequent cause of opportunistic mucosal and systemic infections. Investigation ofC. albicansvirulence 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 withinCandidaspecies), 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 inC. albicansand discuss the use of these approaches to addressing both commensalism and pathogenesis in this species. PMID:26424829

  15. A Candida albicans Strain Expressing Mammalian Interleukin-17A Results in Early Control of Fungal Growth during Disseminated Infection

    PubMed Central

    Huppler, Anna R.; Whibley, Natasha; Woolford, Carol A.; Childs, Erin E.; He, Jie; Biswas, Partha S.; McGeachy, Mandy J.; Mitchell, Aaron P.

    2015-01-01

    Candida albicans is normally a commensal fungus of the human mucosae and skin, but it causes life-threatening systemic infections in hospital settings in the face of predisposing conditions, such as indwelling catheters, abdominal surgery, or antibiotic use. Immunity to C. albicans involves various immune parameters, but the cytokine interleukin-17A (IL-17A) (also known as IL-17) has emerged as a centrally important mediator of immune defense against both mucosal and systemic candidiasis. Conversely, IL-17A has been suggested to enhance the virulence of C. albicans, indicating that it may exert detrimental effects on pathogenesis. In this study, we hypothesized that a C. albicans strain expressing IL-17A would exhibit reduced virulence in vivo. To that end, we created a Candida-optimized expression cassette encoding murine IL-17A, which was transformed into the DAY286 strain of C. albicans. Candida-derived IL-17A was indistinguishable from murine IL-17A in terms of biological activity and detection in standard enzyme-linked immunosorbent assays (ELISAs). Expression of IL-17A did not negatively impact the growth of these strains in vitro. Moreover, the IL-17A-expressing C. albicans strains showed significantly reduced pathogenicity in a systemic model of Candida infection, mainly evident during the early stages of disease. Collectively, these findings suggest that IL-17A mitigates the virulence of C. albicans. PMID:26150537

  16. Impaired killing of Candida albicans by granulocytes mobilized for transfusion purposes: a role for granule components

    PubMed Central

    Gazendam, Roel P.; van de Geer, Annemarie; van Hamme, John L.; Tool, Anton T.J.; van Rees, Dieke J.; Aarts, Cathelijn E.M.; van den Biggelaar, Maartje; van Alphen, Floris; Verkuijlen, Paul; Meijer, Alexander B.; Janssen, Hans; Roos, Dirk; van den Berg, Timo K.; Kuijpers, Taco W.

    2016-01-01

    Granulocyte transfusions are used to treat neutropenic patients with life-threatening bacterial or fungal infections that do not respond to anti-microbial drugs. Donor neutrophils that have been mobilized with granulocyte-colony stimulating factor (G-CSF) and dexamethasone are functional in terms of antibacterial activity, but less is known about their fungal killing capacity. We investigated the neutrophil-mediated cytotoxic response against C. albicans and A. fumigatus in detail. Whereas G-CSF/dexamethasone-mobilized neutrophils appeared less mature as compared to neutrophils from untreated controls, these cells exhibited normal ROS production by the NADPH oxidase system and an unaltered granule mobilization capacity upon stimulation. G-CSF/dexamethasone-mobilized neutrophils efficiently inhibited A. fumigatus germination and killed Aspergillus and Candida hyphae, but the killing of C. albicans yeasts was distinctly impaired. Following normal Candida phagocytosis, analysis by mass spectrometry of purified phagosomes after fusion with granules demonstrated that major constituents of the antimicrobial granule components, including major basic protein (MBP), were reduced. Purified MBP showed candidacidal activity, and neutrophil-like Crisp-Cas9 NB4-KO-MBP differentiated into phagocytes were impaired in Candida killing. Together, these findings indicate that G-CSF/dexamethasone-mobilized neutrophils for transfusion purposes have a selectively impaired capacity to kill Candida yeasts, as a consequence of an altered neutrophil granular content. PMID:26802050

  17. Impaired killing of Candida albicans by granulocytes mobilized for transfusion purposes: a role for granule components.

    PubMed

    Gazendam, Roel P; van de Geer, Annemarie; van Hamme, John L; Tool, Anton T J; van Rees, Dieke J; Aarts, Cathelijn E M; van den Biggelaar, Maartje; van Alphen, Floris; Verkuijlen, Paul; Meijer, Alexander B; Janssen, Hans; Roos, Dirk; van den Berg, Timo K; Kuijpers, Taco W

    2016-05-01

    Granulocyte transfusions are used to treat neutropenic patients with life-threatening bacterial or fungal infections that do not respond to anti-microbial drugs. Donor neutrophils that have been mobilized with granulocyte-colony stimulating factor (G-CSF) and dexamethasone are functional in terms of antibacterial activity, but less is known about their fungal killing capacity. We investigated the neutrophil-mediated cytotoxic response against C. albicans and A. fumigatus in detail. Whereas G-CSF/dexamethasone-mobilized neutrophils appeared less mature as compared to neutrophils from untreated controls, these cells exhibited normal ROS production by the NADPH oxidase system and an unaltered granule mobilization capacity upon stimulation. G-CSF/dexamethasone-mobilized neutrophils efficiently inhibited A. fumigatus germination and killed Aspergillus and Candida hyphae, but the killing of C. albicans yeasts was distinctly impaired. Following normal Candida phagocytosis, analysis by mass spectrometry of purified phagosomes after fusion with granules demonstrated that major constituents of the antimicrobial granule components, including major basic protein (MBP), were reduced. Purified MBP showed candidacidal activity, and neutrophil-like Crisp-Cas9 NB4-KO-MBP differentiated into phagocytes were impaired in Candida killing. Together, these findings indicate that G-CSF/dexamethasone-mobilized neutrophils for transfusion purposes have a selectively impaired capacity to kill Candida yeasts, as a consequence of an altered neutrophil granular content. PMID:26802050

  18. Azole-resistant Candida albicans from a wild Brazilian porcupine (Coendou prehensilis): a sign of an environmental imbalance?

    PubMed

    Castelo-Branco, D S C M; Brilhante, R S N; Paiva, M A N; Teixeira, C E C; Caetano, E P; Ribeiro, J F; Cordeiro, R A; Sidrim, J J C; Monteiro, A J; Rocha, M F G

    2013-07-01

    This study aimed at evaluating the in vitro antifungal susceptibility of Candida albicans isolates obtained during necropsy of a wild Brazilian porcupine and the mechanism of azole resistance. Initially, we investigated the in vitro susceptibility of the three isolates to amphotericin B, caspofungin, fluconazole, itraconazole, ketoconazole and voriconazole. Afterwards, three sub-inhibitory concentrations (47, 21 and 12 mg/l) of promethazine, an efflux pump inhibitor, were tested in combination with the antifungal drugs in order to evaluate the role of these pumps in the development of antifungal resistance. In addition, the three isolates were submitted to RAPD-PCR and M13-fingerprinting analyses. The minimum inhibitory concentrations (MICs) obtained with the isolates were 1, 0.03125, 250, 125, 8 and 250 mg/l for amphotericin B, caspofungin, fluconazole, itraconazole, ketoconazole and voriconazole, respectively, and the isolates were found to be resistant to all tested azoles. The addition of the three subinhibitory concentrations of promethazine resulted in statistically significant (P < 0.05) reductions in the MICs for all tested drugs, with decreases to azoles being statistically greater than those for amphotericin B and caspofungin (P < 0.05). The molecular analyses showed a genetic similarity among the three tested isolates, suggesting the occurrence of candidemia in the studied animal. These findings highlight the importance of monitoring antifungal susceptibility of Candida spp. from veterinary sources, especially as they may indicate the occurrence of primary azole resistance even in wild animals. PMID:23286353

  19. Nucleotide substitutions in the Candida albicans ERG11 gene of azole-susceptible and azole-resistant clinical isolates.

    PubMed

    Strzelczyk, Joanna Katarzyna; Slemp-Migiel, Anna; Rother, Magdalena; Gołąbek, Karolina; Wiczkowski, Andrzej

    2013-01-01

    One of the mechanisms of Candida albicans resistance to azole drugs used in antifungal therapy relies on increased expression and presence of point mutations in the ERG11 gene that encodes sterol 14α demethylase (14DM), an enzyme which is the primary target for the azole class of antifungals. The aim of the study was to analyze nucleotide substitutions in the Candida albicans ERG11 gene of azole-susceptible and azole-resistant clinical isolates. The Candida albicans isolates represented a collection of 122 strains selected from 658 strains isolated from different biological materials. Samples were obtained from hospitalized patients. Fluconazole susceptibility was tested in vitro using a microdilution assay. Candida albicans strains used in this study consisted of two groups: 61 of the isolates were susceptible to azoles and the 61 were resistant to azoles. Four overlapping regions of the ERG11 gene of the isolates of Candida albicans strains were amplified and sequenced. The MSSCP (multitemperature single strand conformation polymorphism) method was performed to select Candida albicans samples presenting genetic differences in the ERG11 gene fragments for subsequent sequence analysis. Based on the sequencing results we managed to detect 19 substitutions of nucleotides in the ERG11 gene fragments. Sequencing revealed 4 different alterations: T495A, A530C, G622A and A945C leading to changes in the corresponding amino acid sequence: D116E, K128T, V159I and E266D. The single nucleotide changes in the ERG11 gene did not affect the sensitivity of Candida albicans strains, whereas multiple nucleotide substitutions in the ERG11 gene fragments indicated a possible relation with the increase in resistance to azole drugs. PMID:24340302

  20. Adherence of Candida albicans to human buccal epithelial cells: host-induced protein synthesis and signaling events.

    PubMed Central

    Bailey, A; Wadsworth, E; Calderone, R

    1995-01-01

    The synthesis of proteins by Candida albicans was studied following adherence of blastoconidia to human buccal epithelial cells (HBEC). Initially, labeling of HBEC, C. albicans, and HBEC-C. albicans with [35S]methionine was performed. After a 3-h incubation and prior to labeling with [35S]methionine, the cultures were treated with cycloheximide to prevent HBEC protein synthesis. The HBEC-C. albicans mixture as well as C. albicans and HBEC incubated separately were extracted with beta-mercaptoethanol (beta-ME). These extracts as well as the cell residue (solubilized by boiling with sodium dodecyl sulfate [SDS]) were examined by SDS-polyacrylamide gel electrophoresis and autoradiography. In comparison to cultures of C. albicans incubated without HBEC, proteins with molecular masses of approximately 52 to 56 kDa from beta-ME extracts and from SDS-solubilized cells were observed only from adhering cultures. In addition, unlabeled beta-ME extracts were electrotransferred to nitrocellulose and immunoblotted with antiphosphotyrosine antibodies to determine whether cell signaling events were occurring during adherence. Proteins with molecular masses of 54 and 60 kDa were recognized only in mixed cultures of C. albicans and HBEC. These data indicate that following adherence of C. albicans to HBEC, new Candida proteins are expressed. Further, these events are accompanied by the expression of signal proteins, presumably of Candida origin. PMID:7822023

  1. Mechanism of iron uptake by the pathogenic yeast, Candida albicans

    SciTech Connect

    Ismail, A.

    1986-01-01

    C. albicans requires iron for growth and phenotypic development. When deprived of iron, mycelium and bud formation was suppressed. Survival of the organism was also reduced under iron-limiting conditions. The combination of elevated temperature and iron-deprivation further reduced phenotypic development and survival of the yeast. The combination of elevated temperature and iron starvation resulted in a decrease in both the growth rate and siderophore production. However, with time, the cells were able to show partial recovery in the growth rate which occurred concomitantly with an increase in siderophore production. In order for siderophores to be utilized, ferri-siderophore receptors must be produced. The receptor was shown to be located in the plasma membrane of the yeast. Scatchard analysis of the binding of ferri-siderophores to plasma membrane receptors showed an increase in receptor affinity and number of binding sites in iron-starved cells when compared to control cells. Autoradiograms of the /sup 58/Fe-siderophore-protein complex following SDS-PAGE separation of candidal proteins revealed the presence of a ferri-siderophore receptor of approximately 10,000 daltons. C. albicans strains which lacked the ability to synthesize phenolate siderophore maintained a phenolate receptor and bound candidal phenolate siderophore better than non-candidal phenolate siderophores.

  2. Fimbria-mediated adherence of Candida albicans to glycosphingolipid receptors on human buccal epithelial cells.

    PubMed Central

    Yu, L; Lee, K K; Sheth, H B; Lane-Bell, P; Srivastava, G; Hindsgaul, O; Paranchych, W; Hodges, R S; Irvin, R T

    1994-01-01

    Candida albicans is an opportunist fungal pathogen that has the ability to adhere to host cell surface receptors via a number of adhesins. Yu et al. (L. Yu, K. K. Lee, K. Ens, P. C. Doig, M. R. Carpenter, W. Staddon, R. S. Hodges, W. Paranchych, and R. T. Irvin, Infect. Immun. 62:2834-2842, 1994) described the purification and initial characterization of a fimbrial adhesin from C. albicans. In this paper, we show that C. albicans fimbriae also bind to asialo-GM1 [gangliotetraosylceramide: beta Gal(1-3)beta GalNAc(1-4) beta Gal(1-4)beta Glc(1-1)Cer] immobilized on microtiter plates in a saturable and concentration-dependent manner. C. albicans fimbrial binding to exfoliated human buccal epithelial cells (BECs) was inhibited by asialo-GM1 in in vitro binding assays. The fimbriae interact with the glycosphingolipid receptors via the carbohydrate portion of the receptors, since fimbriae were observed to bind to synthetic beta GalNAc(1-4)beta Gal-protein conjugates and the disaccharide was able to inhibit binding of fimbriae to BECs in in vitro binding assays. We conclude from these results that the C. albicans yeast form expresses a fimbrial adhesin that binds to glycosphingolipids displayed on the surface of human BECs. Images PMID:8005674

  3. A comprehensive Candida albicans PeptideAtlas build enables deep proteome coverage.

    PubMed

    Vialas, Vital; Sun, Zhi; Reales-Calderón, Jose A; Hernáez, María L; Casas, Vanessa; Carrascal, Montserrat; Abián, Joaquín; Monteoliva, Lucía; Deutsch, Eric W; Moritz, Robert L; Gil, Concha

    2016-01-10

    To provide new and expanded proteome documentation of the opportunistically pathogen Candida albicans, we have developed new protein extraction and analysis routines to provide a new, extended and enhanced version of the C. albicans PeptideAtlas. Two new datasets, resulting from experiments consisting of exhaustive subcellular fractionations and different growing conditions, plus two additional datasets from previous experiments on the surface and the secreted proteomes, have been incorporated to increase the coverage of the proteome. High resolution precursor mass spectrometry (MS) and ion trap tandem MS spectra were analyzed with three different search engines using a database containing allele-specific sequences. This approach, novel for a large-scale C. albicans proteomics project, was combined with the post-processing and filtering implemented in the Trans Proteomic Pipeline consistently used in the PeptideAtlas project and resulted in 49,372 additional peptides (3-fold increase) and 1630 more proteins (1.6-fold increase) identified in the new C. albicans PeptideAtlas with respect to the previous build. A total of 71,310 peptides and 4174 canonical (minimal non-redundant set) proteins (4115 if one protein per pair of alleles is considered) were identified representing 66% of the 6218 proteins in the predicted proteome. This makes the new PeptideAtlas build the most comprehensive C. albicans proteomics resource available and the only large-scale one with detections of individual alleles. PMID:26493587

  4. In vivo evaluation of photodynamic inactivation using Photodithazine® against Candida albicans.

    PubMed

    Carmello, J C; Dovigo, L N; Mima, E G; Jorge, J H; de Souza Costa, C A; Bagnato, V S; Pavarina, A C

    2015-07-01

    This study describes the photoinactivation of Candida albicans in a murine model of oral candidosis, mediated by Photodithazine® (PDZ). Six-week-old female Swiss mice were immunosuppressed, and inoculated with C. albicans to induce oral candidosis. After five days, photodynamic inactivation (PDI) mediated by PDZ at concentrations of 75, 100, 125 and 150 mg L(-1) was applied on the tongue of mice. Next, microbiological evaluation was performed by recovering C. albicans from the tongue via colony forming units (CFU mL(-1)). After 24 h of treatment, the animals were killed and the tongues were surgically removed for histological analysis. PDI was effective in reducing C. albicans on the tongue of mice using 100 mg L(-1) of PDZ, when compared to the positive control group (without treatment). No adverse effect on the tongue tissue was verified after PDI. Therefore, PDI was effective for inactivation of C. albicans without causing any harmful effects on host tissues, which is promising for future clinical trials. PMID:26069900

  5. Inhibitory Effect of Sophorolipid on Candida albicans Biofilm Formation and Hyphal Growth

    PubMed Central

    Haque, Farazul; Alfatah, Md.; Ganesan, K.; Bhattacharyya, Mani Shankar

    2016-01-01

    Candida albicans causes superficial and life-threatening systemic infections. These are difficult to treat often due to drug resistance, particularly because C. albicans biofilms are inherently resistant to most antifungals. Sophorolipid (SL), a glycolipid biosurfactant, has been shown to have antimicrobial and anticancer properties. In this study, we investigated the effect of SL on C. albicans biofilm formation and preformed biofilms. SL was found to inhibit C. albicans biofilm formation as well as reduce the viability of preformed biofilms. Moreover, SL, when used along with amphotericin B (AmB) or fluconazole (FLZ), was found to act synergistically against biofilm formation and preformed biofilms. Effect of SL on C. albicans biofilm formation was further visualized by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), which revealed absence of hyphae, typical biofilm architecture and alteration in the morphology of biofilm cells. We also found that SL downregulates the expression of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4, which possibly explains the inhibitory effect of SL on hyphae and biofilm formation. PMID:27030404

  6. Transcriptional response to fluconazole and amphotericin B in Candida albicans biofilms.

    PubMed

    Nailis, Heleen; Vandenbosch, Davy; Deforce, Dieter; Nelis, Hans J; Coenye, Tom

    2010-05-01

    Biofilm formation is often associated with persistent Candida albicans infections. Treatment of these infections is difficult, since sessile C. albicans cells show increased resistance towards antifungal agents. The molecular mechanisms behind biofilm resistance in C. albicans are not yet understood. In the present study, we investigated the transcriptional response in young and mature in vitro-grown biofilms after a short and longer exposure time to high doses of fluconazole or amphotericin B. Treatment of biofilms with high doses of antifungal agents resulted in a drug-specific transcriptional response. Exposure of biofilms to fluconazole induced upregulation of genes encoding enzymes involved in ergosterol biosynthesis (ERG1, ERG3, ERG11 and ERG25). Treatment of biofilms with amphotericin B resulted in an overexpression of KRE1 and SKN1, two genes encoding proteins involved in beta-1,6-glucan biosynthesis. Our data indicate that sessile C. albicans cells show controlled regulation of gene expression, as they quickly mount a drug-specific transcriptional response in the presence of high doses of antifungal agents. These transcriptional changes suggest upregulation of ergosterol biosynthesis (fluconazole) and upregulation of beta-1,6-glucan biosynthesis (amphotericin B) in sessile C. albicans cells that might contribute to a resistant biofilm phenotype. PMID:20170727

  7. Candida albicans Primes TLR Cytokine Responses through a Dectin-1/Raf-1–Mediated Pathway

    PubMed Central

    Ifrim, Daniela C.; Joosten, Leo A. B.; Kullberg, Bart-Jan; Jacobs, Liesbeth; Jansen, Trees; Williams, David L.; Gow, Neil A. R.; van der Meer, Jos W. M.; Netea, Mihai G.

    2013-01-01

    The immune system is essential to maintain homeostasis with resident microbial populations, ensuring that the symbiotic host–microbial relationship is maintained. In parallel, commensal microbes significantly shape mammalian immunity at the host mucosal surface, as well as systemically. Candida albicans is an opportunistic pathogen that lives as a commensal on skin and mucosa of healthy individuals. Little is known about its capacity to modulate responses toward other microorganisms, such as colonizing bacteria (e.g., intestinal microorganisms). The aim of this study was to assess the cytokine production of PBMCs induced by commensal bacteria when these cells were primed by C. albicans. We show that C. albicans and β-1,3-glucan induce priming of human primary mononuclear cells and this leads to enhanced cytokine production upon in vitro stimulation with TLR ligands and bacterial commensals. This priming requires the β-1,3-glucan receptor dectin-1 and the noncanonical Raf-1 pathway. In addition, although purified mannans cannot solely mediate the priming, the presence of mannosyl residues in the cell wall of C. albicans is nevertheless required. In conclusion, C. albicans is able to modify cytokine responses to TLR ligands and colonizing bacteria, which is likely to impact the inflammatory reaction during mucosal diseases. PMID:23475217

  8. In vivo photodynamic inactivation of Candida albicans using chloro-aluminum phthalocyanine.

    PubMed

    Carmello, J C; Alves, F; Ribeiro, Apd; Basso, F G; de Souza Costa, C A; Tedesco, A C; Primo, F L; Mima, E G; Pavarina, A C

    2016-07-01

    This study evaluated the photoinactivation of Candida albicans in a murine model of oral candidiasis using chloro-aluminum phthalocyanine (ClAlP) encapsulated in cationic nanoemulsions (NE) and chloro-aluminum phthalocyanine (ClAlP) diluted in DMSO (DMSO) as photosensitizer (PS). Seventy-five 6-week-old female Swiss mice were immunosuppressed and inoculated with C. albicans to induce oral candidiasis. PDT was performed on the tongue by the application of the photosensitizers and LED light (100 J cm(-2) -660 nm). Twenty-four hours and 7 days after treatments, microbiological evaluation was carried out by recovering C. albicans from the tongue of animals (CFU ml(-1) ). Then, mice were sacrificed and the tongues were surgically removed for histological and biomolecular analysis of pro- and anti-inflammatory cytokines. Data were analyzed by ANOVA followed by Tukey's post hoc test. ClAlP-NE-mediated PDT reduced 2.26 log10 of C. albicans recovered from the tongue when compared with the control group (P-L-) (P < 0.05). PDT did not promote adverse effects on the tongue tissue. Seven days after treatment, all animals were completely healthy. In summary, PDT mediated by chloro-aluminum phthalocyanine entrapped in cationic nanoemulsions was effective in reducing C. albicans recovered from the oral lesions of immunocompromised mice. PMID:26914185

  9. Stimulation of superoxide production increases fungicidal action of miconazole against Candida albicans biofilms

    PubMed Central

    De Cremer, Kaat; De Brucker, Katrijn; Staes, Ines; Peeters, Annelies; Van den Driessche, Freija; Coenye, Tom; Cammue, Bruno P. A.; Thevissen, Karin

    2016-01-01

    We performed a whole-transcriptome analysis of miconazole-treated Candida albicans biofilms, using RNA-sequencing. Our aim was to identify molecular pathways employed by biofilm cells of this pathogen to resist action of the commonly used antifungal miconazole. As expected, genes involved in sterol biosynthesis and genes encoding drug efflux pumps were highly induced in biofilm cells upon miconazole treatment. Other processes were affected as well, including the electron transport chain (ETC), of which eight components were transcriptionally downregulated. Within a diverse set of 17 inhibitors/inducers of the transcriptionally affected pathways, the ETC inhibitors acted most synergistically with miconazole against C. albicans biofilm cells. Synergy was not observed for planktonically growing C. albicans cultures or when biofilms were treated in oxygen-deprived conditions, pointing to a biofilm-specific oxygen-dependent tolerance mechanism. In line, a correlation between miconazole’s fungicidal action against C. albicans biofilm cells and the levels of superoxide radicals was observed, and confirmed both genetically and pharmacologically using a triple superoxide dismutase mutant and a superoxide dismutase inhibitor N-N′-diethyldithiocarbamate, respectively. Consequently, ETC inhibitors that result in mitochondrial dysfunction and affect production of reactive oxygen species can increase miconazole’s fungicidal activity against C. albicans biofilm cells. PMID:27272719

  10. Endogenous nitric oxide accumulation is involved in the antifungal activity of Shikonin against Candida albicans.

    PubMed

    Liao, Zebin; Yan, Yu; Dong, Huaihuai; Zhu, Zhenyu; Jiang, Yuanying; Cao, Yingying

    2016-01-01

    The aim of the present study was to investigate the role of nitric oxide (NO) in the antifungal activity of Shikonin (SK) against Candida albicans (C. albicans) and to clarify the underlying mechanism. The results showed that the NO donors S-nitrosoglutathione (GSNO) and L-arginine could enhance the antifungal activity of SK, whereas the NO production inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) attenuated antifungal action. Using the fluorescent dye 3-amino,4-aminomethyl-2', 7-difluorescein, diacetate (DAF-FM DA), we found that the accumulation of NO in C. albicans was increased markedly by SK in a time- and dose-dependent manner. In addition, the results of real-time reverse transcription-PCR (RT-PCR) demonstrated that the transcription level of YHB1 in C. albicans was greatly increased upon incubation of SK. Consistently, the YHB1-null mutant (yhb1Δ/Δ) exhibited a higher susceptibility to SK than wild-type cells. In addition, although the transcription level of CTA4 in C. albicans was not significantly changed when exposed to SK, the CTA4-null mutant (cta4Δ/Δ) was more susceptible to SK. Collectively, SK is the agent found to execute its antifungal activity directly via endogenous NO accumulation, and NO-mediated damage is related to the suppression of YHB1 and the function of CTA4. PMID:27530748

  11. In vivo role of Candida albicans β-hexosaminidase (HEX1) in carbon scavenging

    PubMed Central

    Ruhela, Deepa; Kamthan, Mohan; Saha, Paramita; Majumdar, Subeer S; Datta, Kasturi; Abdin, Malik Zainul; Datta, Asis

    2015-01-01

    The capability to utilize of N-acetylglucosamine (GlcNAc) as a carbon source is an important virulence attribute of Candida albicans. But there is a lack of information about the in vivo source of GlcNAc for the pathogen within the host environment. Here, we have characterized the GlcNAc-inducible β-hexosaminidase gene (HEX1) of C. albicans showing a role in carbon scavenging. In contrast to earlier studies, we have reported HEX1 to be a nonessential gene as shown by homozygous trisomy test. Virulence study in the systemic mouse murine model showed that Δhex1 strain is significantly less virulent in comparison to the wild-type strain. Moreover, Δhex1 strain also showed a higher susceptibility to peritoneal macrophages. In an attempt to determine possible substrates of Hex1, hyaluronic acid (HA) was treated with purified Hex1 enzyme. A significant release of GlcNAc was observed by gas chromatography-mass spectrometry analysis analysis suggesting HA degradation. Interestingly, immunohistochemistry analysis showed significant accumulation of HA in the mice kidney infected with the wild-type strain of C. albicans. Northern blot analysis showed that C. albicans HEX1 is expressed during mice renal colonization. Thus, C. albicans can obtain GlcNAc during organ colonization by secreting Hex1 via degradation of host HA. PMID:26177944

  12. Stimulation of superoxide production increases fungicidal action of miconazole against Candida albicans biofilms.

    PubMed

    De Cremer, Kaat; De Brucker, Katrijn; Staes, Ines; Peeters, Annelies; Van den Driessche, Freija; Coenye, Tom; Cammue, Bruno P A; Thevissen, Karin

    2016-01-01

    We performed a whole-transcriptome analysis of miconazole-treated Candida albicans biofilms, using RNA-sequencing. Our aim was to identify molecular pathways employed by biofilm cells of this pathogen to resist action of the commonly used antifungal miconazole. As expected, genes involved in sterol biosynthesis and genes encoding drug efflux pumps were highly induced in biofilm cells upon miconazole treatment. Other processes were affected as well, including the electron transport chain (ETC), of which eight components were transcriptionally downregulated. Within a diverse set of 17 inhibitors/inducers of the transcriptionally affected pathways, the ETC inhibitors acted most synergistically with miconazole against C. albicans biofilm cells. Synergy was not observed for planktonically growing C. albicans cultures or when biofilms were treated in oxygen-deprived conditions, pointing to a biofilm-specific oxygen-dependent tolerance mechanism. In line, a correlation between miconazole's fungicidal action against C. albicans biofilm cells and the levels of superoxide radicals was observed, and confirmed both genetically and pharmacologically using a triple superoxide dismutase mutant and a superoxide dismutase inhibitor N-N'-diethyldithiocarbamate, respectively. Consequently, ETC inhibitors that result in mitochondrial dysfunction and affect production of reactive oxygen species can increase miconazole's fungicidal activity against C. albicans biofilm cells. PMID:27272719

  13. Transcriptomics Analysis of Candida albicans Treated with Huanglian Jiedu Decoction Using RNA-seq.

    PubMed

    Yang, Qianqian; Gao, Lei; Tao, Maocan; Chen, Zhe; Yang, Xiaohong; Cao, Yi

    2016-01-01

    Candida albicans is the major invasive fungal pathogen of humans, causing diseases ranging from superficial mucosal infections to disseminated, systemic infections that are often life-threatening. Resistance of C. albicans to antifungal agents and limited antifungal agents has potentially serious implications for management of infections. As a famous multiherb prescription in China, Huanglian Jiedu Decoction (HLJJD, Orengedokuto in Japan) is efficient against Trichophyton mentagrophytes and C. albicans. But the antifungal mechanism of HLJDD remains unclear. In this study, by using RNA-seq technique, we performed a transcriptomics analysis of gene expression changes for C. albicans under the treatment of HLJDD. A total of 6057 predicted protein-encoding genes were identified. By gene expression analysis, we obtained a total of 735 differentially expressed genes (DEGs), including 700 upregulated genes and 35 downregulated genes. Genes encoding multidrug transporters such as ABC transporter and MFS transporter were identified to be significantly upregulated. Meanwhile, by pathway enrichment analysis, we identified 26 significant pathways, in which pathways of DNA replication and transporter activity were mainly involved. These results might provide insights for the inhibition mechanism of HLJDD against C. albicans. PMID:27143984

  14. Human salivary histatin 5 fungicidal action does not induce programmed cell death pathways in Candida albicans.

    PubMed

    Wunder, David; Dong, Jin; Baev, Didi; Edgerton, Mira

    2004-01-01

    Salivary histatins (Hsts) are potent candidacidal proteins that induce a nonlytic form of cell death in Candida albicans accompanied by loss of mean cell volume, cell cycle arrest, and elevation of intracellular levels of reactive oxygen species (ROS). Since these phenotypes are often markers of programmed cell death and apoptosis, we investigated whether other classical markers of apoptosis, including generation of intracellular ROS and protein carbonyl groups, chromosomal fragmentation (laddering), and cytochrome c release, are found in Hst 5-mediated cell death. Increased intracellular levels of ROS in C. albicans were detected in cells both following exogenous application of Hst 5 and following intracellular expression of Hst 5. However, Western blot analysis failed to detect specifically increased protein carbonylation in Hst 5-treated cells. There was no evidence of chromosomal laddering and no cytochrome c release was observed following treatment of C. albicans mitochondria with Hst 5. Superoxide dismutase enzymes of C. albicans and Saccharomyces cerevisiae provide essential protection against oxidative stress; therefore, we tested whether SOD mutants have increased susceptibility to Hst 5, as expected if ROS mediate fungicidal effects. Cell survival of S. cerevisiae SOD1/SOD2 mutants and C. albicans SOD1 mutants following Hst 5 treatment (31 micro M) was indistinguishable from the survival of wild-type cells treated with Hst 5. We conclude that ROS may not play a direct role in fungicidal activity and that Hst 5 does not initiate apoptosis or programmed cell death pathways. PMID:14693527

  15. Transcriptomics Analysis of Candida albicans Treated with Huanglian Jiedu Decoction Using RNA-seq

    PubMed Central

    Yang, Qianqian; Gao, Lei; Tao, Maocan; Chen, Zhe; Yang, Xiaohong; Cao, Yi

    2016-01-01

    Candida albicans is the major invasive fungal pathogen of humans, causing diseases ranging from superficial mucosal infections to disseminated, systemic infections that are often life-threatening. Resistance of C. albicans to antifungal agents and limited antifungal agents has potentially serious implications for management of infections. As a famous multiherb prescription in China, Huanglian Jiedu Decoction (HLJJD, Orengedokuto in Japan) is efficient against Trichophyton mentagrophytes and C. albicans. But the antifungal mechanism of HLJDD remains unclear. In this study, by using RNA-seq technique, we performed a transcriptomics analysis of gene expression changes for C. albicans under the treatment of HLJDD. A total of 6057 predicted protein-encoding genes were identified. By gene expression analysis, we obtained a total of 735 differentially expressed genes (DEGs), including 700 upregulated genes and 35 downregulated genes. Genes encoding multidrug transporters such as ABC transporter and MFS transporter were identified to be significantly upregulated. Meanwhile, by pathway enrichment analysis, we identified 26 significant pathways, in which pathways of DNA replication and transporter activity were mainly involved. These results might provide insights for the inhibition mechanism of HLJDD against C. albicans. PMID:27143984

  16. Cloning and characterization of the plasma membrane H(+)-ATPase from Candida albicans.

    PubMed Central

    Monk, B C; Kurtz, M B; Marrinan, J A; Perlin, D S

    1991-01-01

    The Candida albicans PMA1 gene was isolated from a genomic library by using a hybridization probe obtained from the PMA1 gene of Saccharomyces cerevisiae. The gene was localized to chromosome III of the Candida genome. An open reading frame of 2,685 nucleotides predicts an amino acid sequence of 895 amino acids that is 83% homologous at both the DNA and protein levels to its S. cerevisiae equivalent. A polyadenylated mRNA transcript of about 4,000 nucleotides contains a highly folded AU-rich leader of 242 nucleotides. The structure of the gene, codon bias, and levels of approximately 100-kDa H(+)-ATPase protein recovered in plasma membranes indicate a highly expressed gene. The plasma membrane ATPase was purified to about 90% homogeneity and appeared to be blocked at the amino terminus. Three hydrophobic membrane sector tryptic fragments from the partially digested ATPase provided internal sequence information for over 50 amino acids, which agrees with the sequence predicted by the cloned gene. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the C. albicans enzyme is about 3 kDa smaller than its Saccharomyces counterpart and was consistent with a predicted Mr of 97,398. Antibodies to the S. cerevisiae whole ATPase or its carboxyl terminus bound to the C. albicans enzyme but with lower avidity. Kinetic analysis showed that the Candida and Saccharomyces ATPases respond to glucose activation-starvation in nonidentical fashions. The amino-terminal domain of the C. albicans ATPase is marked by a net deletion of 23 amino acids in comparison with the S. cerevisiae ATPase. These differences maintain net charge, occur in nonconserved regions of fungal ATPases, and are sufficient to account for the observed difference in electrophoretic mobility between the two yeast ATPases. Images FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 7 PMID:1834633

  17. Prostaglandin E2 from Candida albicans Stimulates the Growth of Staphylococcus aureus in Mixed Biofilms

    PubMed Central

    Krause, Jan; Geginat, Gernot; Tammer, Ina

    2015-01-01

    Background Previous studies showed that Staphylococcus aureus and Candida albicans interact synergistically in dual species biofilms resulting in enhanced mortality in animal models. Methodology/Principal Findings The aim of the current study was to test possible candidate molecules which might mediate this synergistic interaction in an in vitro model of mixed biofilms, such as farnesol, tyrosol and prostaglandin (PG) E2. In mono-microbial and dual biofilms of C.albicans wild type strains PGE2 levels between 25 and 250 pg/mL were measured. Similar concentrations of purified PGE2 significantly enhanced S.aureus biofilm formation in a mode comparable to that observed in dual species biofilms. Supernatants of the null mutant deficient in PGE2 production did not stimulate the proliferation of S.aureus and the addition of the cyclooxygenase inhibitor indomethacin blocked the S.aureus biofilm formation in a dose-dependent manner. Additionally, S. aureus biofilm formation was boosted by low and inhibited by high farnesol concentrations. Supernatants of the farnesol-deficient C. albicans ATCC10231 strain significantly enhanced the biofilm formation of S. aureus but at a lower level than the farnesol producer SC5314. However, C. albicans ATCC10231 also produced PGE2 but amounts were significantly lower compared to SC5314. Conclusion/Significance In conclision, we identified C. albicans PGE2 as a key molecule stimulating the growth and biofilm formation of S. aureus in dual S. aureus/C. albicans biofilms, although C. albicans derived farnesol, but not tyrosol, may also contribute to this effect but to a lesser extent. PMID:26262843

  18. Evaluation of APR1 Gene Expression in Candida albicans Strains Isolated From Patients With Multiple Sclerosis

    PubMed Central

    Amri Saroukolaei, Shahla; Ghabaee, Mojdeh; Shokri, Hojjatollah; Khosravi, Alireza; Badiei, Alireza

    2016-01-01

    Background Intracellular aspartic proteinase A enzyme is expressed by the APR1 gene and is one of the important factors in the development of systemic candidiasis caused by Candida albicans. Objectives The aim of this study was to evaluate the expression of the APR1 gene in C. albicans isolates obtained from patients with multiple sclerosis (MS) and from controls. Patients and Methods The samples were obtained from 135 MS patients with candidiasis and 100 matched controls of healthy individuals during 2010 - 2011. The clinical and control isolates of C. albicans obtained from individuals were cultured onto sabouraud dextrose agar (SDA). The evaluation of APR1 gene expression was performed using the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Results There was a statistically significant difference in APR1 gene expression of C. albicans strains between MS patients (mean ± SD: 0.5208 ± 0.11518) and the control group (mean ± SD: 0.7603 ± 0.11405) (P = 0.000). Significant correlations were found between the APR1 gene expression of C. albicans strains from MS patients with regard to age and the expanded disability status scale (EDSS) (P = 0.000). The mean values of EDSS were 1.6074 ± 0.1081 after antifungal treatment and 2.2519 ± 0.1323 before antifungal treatment (P = 0.000). No significant correlation was observed between the APR1 gene expression with regard to sex and MS subtypes. Conclusions The results suggested that APR1 gene expression in C. albicans strains isolated from MS patients may be an important factor for invasive C. albicans strains in the progression of MS disease. PMID:27540458

  19. Antifungal activity of clotrimazole against Candida albicans depends on carbon sources, growth phase and morphology.

    PubMed

    Kasper, Lydia; Miramón, Pedro; Jablonowski, Nadja; Wisgott, Stephanie; Wilson, Duncan; Brunke, Sascha; Hube, Bernhard

    2015-07-01

    Vulvovaginal candidiasis, a superficial infection caused predominantly by the pathogenic fungus Candida albicans, is frequently treated with clotrimazole. Some drug formulations contain lactate for improved solubility. Lactate may modify C. albicans physiology and drug sensitivity by serving as a carbon source for the fungus and/or affecting local pH. Here, we explored the effects of lactate, in combination with pH changes, on C. albicans proliferation, morphology and clotrimazole sensitivity. Moreover, we determined the influence of growth phase and morphology per se on drug sensitivity. We showed that utilization of lactate as a carbon source did not promote fast fungal proliferation or filamentation. Lactate had no influence on clotrimazole-mediated killing of C. albicans in standard fungal cultivation medium but had an additive effect on the fungicidal clotrimazole action under in vitro vagina-simulative conditions. Moreover, clotrimazole-mediated killing was growth-phase and morphology dependent. Post-exponential cells were resistant to the fungicidal action of clotrimazole, whilst logarithmic cells were sensitive, and hyphae showed the highest susceptibility. Finally, we showed that treatment of pre-formed C. albicans hyphae with sublethal concentrations of clotrimazole induced a reversion to yeast-phase growth. As C. albicans hyphae are considered the pathogenic morphology during mucosal infections, these data suggest that elevated fungicidal activity of clotrimazole against hyphae plus clotrimazole-induced hyphae-to-yeast reversion may help to dampen acute vaginal infections by reducing the relative proportion of hyphae and thus shifting to a non-invasive commensal-like population. In addition, lactate as an ingredient of clotrimazole formulations may potentiate clotrimazole killing of C. albicans in the vaginal microenvironment. PMID:25976001

  20. Flavodoxin-Like Proteins Protect Candida albicans from Oxidative Stress and Promote Virulence

    PubMed Central

    Li, Lifang; Naseem, Shamoon; Sharma, Sahil; Konopka, James B.

    2015-01-01

    The fungal pathogen Candida albicans causes lethal systemic infections in humans. To better define how pathogens resist oxidative attack by the immune system, we examined a family of four Flavodoxin-Like Proteins (FLPs) in C. albicans. In agreement with previous studies showing that FLPs in bacteria and plants act as NAD(P)H quinone oxidoreductases, a C. albicans quadruple mutant lacking all four FLPs (pst1Δ, pst2Δ, pst3Δ, ycp4Δ) was more sensitive to benzoquinone. Interestingly, the quadruple mutant was also more sensitive to a variety of oxidants. Quinone reductase activity confers important antioxidant effects because resistance to oxidation was restored in the quadruple mutant by expressing either Escherichia coli wrbA or mammalian NQO1, two distinct types of quinone reductases. FLPs were detected at the plasma membrane in C. albicans, and the quadruple mutant was more sensitive to linolenic acid, a polyunsaturated fatty acid that can auto-oxidize and promote lipid peroxidation. These observations suggested that FLPs reduce ubiquinone (coenzyme Q), enabling it to serve as an antioxidant in the membrane. In support of this, a C. albicans coq3Δ mutant that fails to synthesize ubiquinone was also highly sensitive to oxidative stress. FLPs are critical for survival in the host, as the quadruple mutant was avirulent in a mouse model of systemic candidiasis under conditions where infection with wild type C. albicans was lethal. The quadruple mutant cells initially grew well in kidneys, the major site of C. albicans growth in mice, but then declined after the influx of neutrophils and by day 4 post-infection 33% of the mice cleared the infection. Thus, FLPs and ubiquinone are important new antioxidant mechanisms that are critical for fungal virulence. The potential of FLPs as novel targets for antifungal therapy is further underscored by their absence in mammalian cells. PMID:26325183

  1. Flexible Survival Strategies of Pseudomonas aeruginosa in Biofilms Result in Increased Fitness Compared with Candida albicans *

    PubMed Central

    Purschke, Frauke Gina; Hiller, Ekkehard; Trick, Iris; Rupp, Steffen

    2012-01-01

    The majority of microorganisms persist in nature as surface-attached communities often surrounded by an extracellular matrix, called biofilms. Most natural biofilms are not formed by a single species but by multiple species. Microorganisms not only cooperate as in some multispecies biofilms but also compete for available nutrients. The Gram-negative bacterium Pseudomonas aeruginosa and the polymorphic fungus Candida albicans are two opportunistic pathogens that are often found coexisting in a human host. Several models of mixed biofilms have been reported for these organisms showing antagonistic behavior. To investigate the interaction of P. aeruginosa and C. albicans in more detail, we analyzed the secretome of single and mixed biofilms of both organisms using MALDI-TOF MS/MS at several time points. Overall 247 individual proteins were identified, 170 originated from P. aeruginosa and 77 from C. albicans. Only 39 of the 131 in mixed biofilms identified proteins were assigned to the fungus whereby the remaining 92 proteins belonged to P. aeruginosa. In single-species biofilms, both organisms showed a higher diversity of proteins with 73 being assigned to C. albicans and 154 to P. aeruginosa. Most interestingly, P. aeruginosa in the presence of C. albicans secreted 16 proteins in significantly higher amounts or exclusively among other virulence factors such as exotoxin A and iron acquisition systems. In addition, the high affinity iron-binding siderophore pyoverdine was identified in mixed biofilms but not in bacterial biofilms, indicating that P. aeruginosa increases its capability to sequester iron in competition with C. albicans. In contrast, C. albicans metabolism was significantly reduced, including a reduction in detectable iron acquisition proteins. The results obtained in this study show that microorganisms not only compete with the host for essential nutrients but also strongly with the present microflora in order to gain a competitive advantage. PMID

  2. Assessing the potential of four cathelicidins for the management of mouse candidiasis and Candida albicans biofilms.

    PubMed

    Yu, Haining; Liu, Xuelian; Wang, Chen; Qiao, Xue; Wu, Sijin; Wang, Hui; Feng, Lan; Wang, Yipeng

    2016-02-01

    As the most common fungal pathogen of humans, severe drug resistance has emerged in the clinically isolated Candida albicans, which lead to the urgency to develop novel antifungal agents. Here, four our previously characterized cathelicidins (cathelicidin-BF, Pc-CATH1, Cc-CATH2, Cc-CATH3) were selected and their antifungal activities against C. albicans were evaluated in vitro and in vivo using amphotericin B and LL-37 as control. Results showed that all four cathelicidins could eradicate standard and clinically isolated C. albicans strains with most MIC values ranging from 1 to 16 μg/ml, in less than 0.5 h revealed by time-kill kinetic assay. Four peptides only exhibited slight hemolytic activity with most HC50 > 200 μg/ml, and retained potent anti-C. albicans activity at salt concentrations below and beyond physiological level. In animal experiment, 50 mg/kg administration of the four cathelicidins could significantly reduce the fungal counts in a murine oral candidiasis model induced by clinically isolated C. albicans. The antibiofilm activity of cathelicidin-BF, the most potent among the five peptides was evaluated, and result showed that cathelicidin-BF strongly inhibited C. albicans biofilm formation at 20 μg/ml. Furthermore, cathelicidin-BF also exhibited potent anti-C. albicans activity in established biofilms as measured by metabolic and fluorescent viability assays. Structure-function analyses suggest that they mainly adopt an α-helical conformations, which enable them to act as a membrane-active molecule. Altogether, the four cathelicidins display great potential for antifungal agent development against candidiasis. PMID:26656137

  3. Decrease in Ribosomal RNA in Candida albicans Induced by Serum Exposure

    PubMed Central

    Fleischmann, Jacob; Rocha, Miguel A.

    2015-01-01

    Candida albicans is an important polymorphic human pathogen. It can switch from a unicellular yeast form to germinating hypha, which may play a role in making it the successful pathogen it is. This hyphal transformation can be triggered by various extracellular stimuli, the most potent one being serum from any source. We have previously reported that Candida albicans transiently polyadenylates portions of both the large and small subunits of ribosomal RNA, shortly after serum exposure. Northern blots at the same time suggested that serum might induce a decrease in total ribosomal RNA. We have carried out a number of experiments to carefully assess this possibility and now report that serum significantly reduces ribosomal RNA in Candida albicans. Fluorometric measurements, Northern blotting and quantitative RT-PCR, have all confirmed this decrease. Timed experiments show that serum induces this decrease rapidly, as it was seen in as early as five minutes. Cell mass is not decreased as total cellular protein content remains the same and metabolic activity does not appear to slow, as assessed by XTT assay, and by the observation that cells form hyphal structures robustly. Another hyphal inducer, N-acetylglucosamine, also caused RNA decrease, but to a lesser extent. We also observed it in non-germinating yeast, such as Candida glabrata. The reason for this decrease is unknown and overall our data suggests that decrease in rRNA does not play a causal role in hyphal transformation. Rapid and significant decrease in a molecule so central to the yeast’s biology is of some importance, and further studies, such as its effect on protein metabolism, will be required to better understand its purpose. PMID:25946110

  4. Anticandidal Effect and Mechanisms of Monoterpenoid, Perillyl Alcohol against Candida albicans.

    PubMed

    Ansari, Moiz A; Fatima, Zeeshan; Hameed, Saif

    2016-01-01

    This study explored the antifungal potential of perillyl alcohol (PA), a natural monoterpene alcohol, against most prevalent human fungal pathogen C. albicans, its clinical isolates and four non-albicans species of Candida. To resolve the potential mechanisms, we used whole genome transcriptome analyses of PA treated Candida cells to examine the affected cellular circuitry of this pathogen. The transcriptome data revealed a link between calcineurin signaling and PA as among the several categories of PA responsive genes the down regulation of calcineurin signaling gene CNB1 was noteworthy which was also confirmed by both molecular docking and susceptibility assays. We observed that PA treated Candida phenocopied compromised calcineurin pathway stress responses and turned sensitive to alkaline pH, ionic, membrane, salinity, endoplasmic reticulum and serum stresses. Indispensability of functional calcineurin was further confirmed as calcineurin mutant was hypersensitive to PA while constitutively expressed calcineurin strain remained resistant. We explored that PA leads to perturbed membrane integrity as depicted through depleted ergosterol levels and disrupted pH homeostasis. Moreover, PA caused cell wall damage which was evident from hypersensitivity against cell wall perturbing agents (congo red, calcoflour white), SEM and enhanced rate of cell sedimentation. Furthermore, PA inhibited potential virulence traits including morphological transition, biofilm formation and displayed diminished capacity to adhere both to the polystyrene surface and buccal epithelial cells. The study also revealed that PA leads to cell cycle arrest and mitochondrial dysfunction in C. albicans. Together, the present study provides enough evidence for further work on PA so that better strategies could be employed to treat Candida infections. PMID:27627759

  5. Multilocus sequence typing of Candida albicans isolates from a burn intensive care unit in Iran.

    PubMed

    Afsarian, Mohammad H; Badali, Hamid; Boekhout, Teun; Shokohi, Tahereh; Katiraee, Farzad

    2015-03-01

    Burn intensive care unit (BICU) patients are specifically exposed to deep-seated nosocomial infections due to Candida albicans. Superficial carriage of C. albicans is a potential source of infection and dissemination, and typing methods could be useful to trace the different isolates. Multilocus sequence typing is a powerful genotyping method for pathogenic micro-organisms, including Candida albicans. Thirty clinical isolates of C. albicans obtained from 22 patients that were admitted to the BICU from a burn hospital at Sari, Mazandaran state, Iran, were studied epidemiologically by multilocus sequence typing (MLST). Seventy-five variable nucleotide sites were found. Sixty-two alleles were identified among the seven loci of the C. albicans isolates and one new allele was obtained. Eighteen diploid sequence types (DSTs) were identified, and among those 10 were new. These isolates belonged to nine clonal clusters (CCs) while two isolates occurred as singletons. Eleven (36.7 %) isolates belonged to CC 124 after eBURST analysis and 13 isolates (43.3 %) were assigned to clade 4. Approximately 17 % of the 30 isolates belonged to clade 1 (CC 69 and CC 766). Isolates from several patients with burns were found to be related genetically. Some patients yielded multiple isolates with identical DSTs, suggesting colonization or infection caused by cross-contamination between patients. Isolates that show identical or similar allelic profiles are presumed to be identical or closely related and may be used to evaluate the genetic relationships between isolates from a specific environment such as the BICU. PMID:25596113

  6. In Vitro Analysis of Finasteride Activity against Candida albicans Urinary Biofilm Formation and Filamentation

    PubMed Central

    Chavez-Dozal, Alba A.; Lown, Livia; Jahng, Maximillian; Walraven, Carla J.

    2014-01-01

    Candida albicans is the 3rd most common cause of catheter-associated urinary tract infections, with a strong propensity to form drug-resistant catheter-related biofilms. Due to the limited efficacy of available antifungals against biofilms, drug repurposing has been investigated in order to identify novel agents with activities against fungal biofilms. Finasteride is a 5-α-reductase inhibitor commonly used for the treatment of benign prostatic hyperplasia, with activity against human type II and III isoenzymes. We analyzed the Candida Genome Database and identified a C. albicans homolog of type III 5-α-reductase, Dfg10p, which shares 27% sequence identity and 41% similarity to the human type III 5-α-reductase. Thus, we investigated finasteride for activity against C. albicans urinary biofilms, alone and in combination with amphotericin B or fluconazole. Finasteride alone was highly effective in the prevention of C. albicans biofilm formation at doses of ≥16 mg/liter and the treatment of preformed biofilms at doses of ≥128 mg/liter. In biofilm checkerboard analyses, finasteride exhibited synergistic activity in the prevention of biofilm formation in a combination of 4 mg/liter finasteride with 2 mg/liter fluconazole. Finasteride inhibited filamentation, thus suggesting a potential mechanism of action. These results indicate that finasteride alone is highly active in the prevention of C. albicans urinary biofilms in vitro and has synergistic activity in combination with fluconazole. Further investigation of the clinical utility of finasteride in the prevention of urinary candidiasis is warranted. PMID:25049253

  7. Candida albicans Gene Deletion with a Transient CRISPR-Cas9 System

    PubMed Central

    Min, Kyunghun; Ichikawa, Yuichi

    2016-01-01

    ABSTRACT Clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated gene 9 (CRISPR-Cas9) systems are used for a wide array of genome-editing applications in organisms ranging from fungi to plants and animals. Recently, a CRISPR-Cas9 system has been developed for the diploid fungal pathogen Candida albicans; the system accelerates genetic manipulation dramatically [V. K. Vyas, M. I. Barrasa, and G. R. Fink, Sci Adv 1(3):e1500248, 2015, http://dx.doi.org/10.1126/sciadv.1500248]. We show here that the CRISPR-Cas9 genetic elements can function transiently, without stable integration into the genome, to enable the introduction of a gene deletion construct. We describe a transient CRISPR-Cas9 system for efficient gene deletion in C. albicans. Our observations suggest that there are two mechanisms that lead to homozygous deletions: (i) independent recombination of transforming DNA into each allele and (ii) recombination of transforming DNA into one allele, followed by gene conversion of the second allele. Our approach will streamline gene function analysis in C. albicans, and our results indicate that DNA can function transiently after transformation of this organism. IMPORTANCE The fungus Candida albicans is a major pathogen. Genetic analysis of this organism has revealed determinants of pathogenicity, drug resistance, and other unique biological features, as well as the identities of prospective drug targets. The creation of targeted mutations has been greatly accelerated recently through the implementation of CRISPR genome-editing technology by Vyas et al. [Sci Adv 1(3):e1500248, 2015, http://dx.doi.org/10.1126/sciadv.1500248]. In this study, we find that CRISPR elements can be expressed from genes that are present only transiently, and we develop a transient CRISPR system that further accelerates C. albicans genetic manipulation. PMID:27340698

  8. The effect of two artificial salivas on the adhesion of Candida albicans to heat-polymerized acrylic resin

    PubMed Central

    2015-01-01

    PURPOSE Xerostomia can diminish the quality of life, leads to changes in normal chemical composition of saliva and oral microbiata, and increases the risk for opportunistic infections, such as Candida albicans. Various artificial salivas have been considered for patients with xerostomia. However, the knowledge on the antifungal and antiadhesive activity of artificial saliva substitutes is limited. The aim of the present study was to evaluate influence of two artificial salivas on the adhesion of Candida albicans to the polymethylmethacrylate disc specimens. MATERIALS AND METHODS Two commercial artificial salivas (Saliva Orthana and Biotene Oral Balance Gel) were selected. 45 polymethylmethacrylate disc specimens were prepared and randomly allocated into 3 groups; Saliva Orthana, Biotene-Oral Balance gel and distilled water. Specimens were stored in the artificial saliva or in the sterile distilled water for 60 minutes at 37℃. Then they were exposed to yeast suspensions including Candida albicans. Yeast cells were counted using ×40 magnification under a light microscope and data were analysed. RESULTS Analysis of data indicated statistically significant difference in adhesion of Candida albicans among all experimental groups (P=.000). Findings indicated that Saliva Orthana had higher adhesion scores than the Biotene Oral Balance gel and distilled water (P<.05). CONCLUSION In comparison of Saliva Orthana, the use of Biotene Oral Balance Gel including lysozyme, lactoferrin and peroxidase may be an appropriate treatment method to prevent of adhesion of Candida albicans and related infections in patients with xerostomia. PMID:25932306

  9. Tumor necrosis factor as an autocrine and paracrine signal controlling the macrophage secretory response to Candida albicans.

    PubMed Central

    Blasi, E; Pitzurra, L; Bartoli, A; Puliti, M; Bistoni, F

    1994-01-01

    We have previously demonstrated that the hyphal form of Candida albicans (H-Candida), but not the yeast form (Y-Candida), acts as a macrophage-stimulating agent. The early response (1 to 3 h) of the macrophage cell line ANA-1 to H-Candida results in enhanced tumor necrosis factor (TNF) transcription and production. Here we show that when coincubation times are prolonged (3 to 24 h), Y-Candida also exhibits stimulatory properties. This phenomenon has been ascribed to the occurrence of the dimorphic transition, as demonstrated by microscopic evaluation of the cultures and by experiments in which both killed Y-Candida and the agerminative strain C. albicans PCA-2 failed to induce cytokine production. TNF produced in response to H-Candida acts as an autocrine and paracrine signal controlling the macrophage secretory response to C. albicans. In fact, addition of anti-TNF polyclonal antibodies to the coculture of ANA-1 macrophages and H-Candida results in a marked and time-dependent decrease of TNF transcript levels. Moreover, pretreatment of macrophages with recombinant TNF for 3 h enhances TNF and induces interleukin-1 production in response to both forms of Candida, while pretreatment for 18 h renders macrophages refractory to any stimuli. Interestingly, the kinetics of interleukin-1 transcription and secretion in response to H-Candida are delayed with respect to those of TNF. Overall, these data indicate that TNF, produced by macrophages in response to H-Candida, regulates its own production as well as that of other soluble factors, thus suggesting that this cytokine plays multiple roles in the immune mechanisms involved in Candida infection. Images PMID:8132326

  10. Characterization of Binding of Candida albicans to Small Intestinal Mucin and Its Role in Adherence to Mucosal Epithelial Cells

    PubMed Central

    de Repentigny, Louis; Aumont, Francine; Bernard, Karine; Belhumeur, Pierre

    2000-01-01

    In order to approximate and adhere to mucosal epithelial cells, Candida must traverse the overlying mucus layer. Interactions of Candida species with mucin and human buccal epithelial cells (BECs) were thus investigated in vitro. Binding of the Candida species to purified small intestinal mucin showed a close correlation with their hierarchy of virulence. Significant differences (P < 0.05) were found among three categories of Candida species adhering highly (C. dubliniensis, C. tropicalis, and C. albicans), moderately (C. parapsilosis and C. lusitaniae) or weakly (C. krusei and C. glabrata) to mucin. Adherence of C. albicans to BECs was quantitatively inhibited by graded concentrations of mucin. However, inhibition of adherence was reversed by pretreatment of mucin with pronase or C. albicans secretory aspartyl proteinase Sap2p but not with sodium periodate. Saturable concentration- and time-dependent binding of mucin to C. albicans was abrogated by pronase or Sap2p treatment of mucin but was unaffected by β-mercaptoethanol, sodium periodate, neuraminidase, lectins, or potentially inhibitory sugars. Probing of membrane blots of the mucin with C. albicans revealed binding of the yeast to the 66-kDa cleavage product of the 118-kDa C-terminal glycopeptide of mucin. Although no evidence was found for the participation of C. albicans cell surface mannoproteins in specific receptor-ligand binding to mucin, inhibition of binding by p-nitrophenol (1 mM) and tetramethylurea (0.36 M) revealed that hydrophobic interactions are involved in adherence of C. albicans to mucin. These results suggest that C. albicans may both adhere to and enzymatically degrade mucins by the action of Saps, and that both properties may act to modulate Candida populations in the oral cavity and gastrointestinal tract. PMID:10816460

  11. Early differential molecular response of a macrophage cell line to yeast and hyphal forms of Candida albicans.

    PubMed Central

    Blasi, E; Pitzurra, L; Puliti, M; Lanfrancone, L; Bistoni, F

    1992-01-01

    The dimorphic transition of Candida albicans from the yeast (Y-Candida) to the hyphal (H-Candida) form is a complex event; the relevance of this transition in fungal pathogenicity is still poorly understood. By using a cloned macrophage cell line (ANA-1), we questioned whether the interaction between macrophages and Y-Candida or H-Candida could affect specific cell functions, i.e., tumor necrosis factor and lysozyme production. We found that ANA-1 macrophages selectively responded to H-Candida with increased tumor necrosis factor and downregulated lysozyme, as assessed by measurement of relative mRNA levels and secreted biological activities. The H-Candida-mediated effects were (i) dependent upon the ratio between ANA-1 macrophages and H-Candida, (ii) detectable after 1 h of coincubation, and (iii) accomplished without fungal ingestion. Conversely, Y-Candida, which was found inside the ANA-1 macrophages, did not affect tumor necrosis factor and lysozyme production, nor did it prevent the macrophage response to other stimuli. Overall, these results indicate that a macrophage can distinguish between Y-Candida and H-Candida and that only the latter is able to modulate specific functions. H-Candida is recognized and probably processed as an extracellular target. The possible implication of macrophages as autocrine and paracrine regulatory cells during Candida infections is discussed. Images PMID:1541557

  12. Drug resistance mechanisms and their regulation in non-albicans Candida species.

    PubMed

    Kołaczkowska, Anna; Kołaczkowski, Marcin

    2016-06-01

    Fungal pathogens use various mechanisms to survive exposure to drugs. Prolonged treatment very often leads to the stepwise acquisition of resistance. The limited number of antifungal therapeutics and their mostly fungistatic rather than fungicidal character facilitates selection of resistant strains. These are able to cope with cytotoxic molecules by acquisition of appropriate mutations, re-wiring gene expression and metabolic adjustments. Recent evidence points to the paramount importance of the permeability barrier and cell wall integrity in the process of adaptation to high drug concentrations. Molecular details of basal and acquired drug resistance are best characterized in the most frequent human fungal pathogen, Candida albicans Effector genes directly related to the acquisition of elevated tolerance of this species to azole and echinocandin drugs are well described. The emergence of high-level drug resistance against intrinsically lower susceptibility to azoles in yeast species other than C. albicans is, however, of particular concern. This is due to their steadily increasing contribution to high mortality rates associated with disseminated infections. Recent findings concerning underlying mechanisms associated with elevated drug resistance suggest a link to cell wall and plasma membrane metabolism in non-albicans Candida species. PMID:26801081

  13. Two independent killing mechanisms of Candida albicans by human neutrophils: evidence from innate immunity defects.

    PubMed

    Gazendam, Roel P; van Hamme, John L; Tool, Anton T J; van Houdt, Michel; Verkuijlen, Paul J J H; Herbst, Martin; Liese, Johannes G; van de Veerdonk, Frank L; Roos, Dirk; van den Berg, Timo K; Kuijpers, Taco W

    2014-07-24

    Invasive fungal infections, accompanied by high rates of mortality, represent an increasing problem in medicine. Neutrophils are the major effector immune cells in fungal killing. Based on studies with neutrophils from patients with defined genetic defects, we provide evidence that human neutrophils use 2 distinct and independent phagolysosomal mechanisms to kill Candida albicans. The first mechanism for the killing of unopsonized C albicans was found to be dependent on complement receptor 3 (CR3) and the signaling proteins phosphatidylinositol-3-kinase and caspase recruitment domain-containing protein 9 (CARD9), but was independent of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. The second mechanism for the killing of opsonized C albicans was strictly dependent on Fcγ receptors, protein kinase C (PKC), and reactive oxygen species production by the NADPH oxidase system. Each of the 2 pathways of Candida killing required Syk tyrosine kinase activity, but dectin-1 was dispensable for both of them. These data provide an explanation for the variable clinical presentation of fungal infection in patients suffering from different immune defects, including dectin-1 deficiency, CARD9 deficiency, or chronic granulomatous disease. PMID:24948657

  14. Diverse Nitrogen Sources in Seminal Fluid Act in Synergy To Induce Filamentous Growth of Candida albicans

    PubMed Central

    Alvarez, Francisco J.; Ryman, Kicki; Hooijmaijers, Cornelis; Bulone, Vincent

    2015-01-01

    The pathogenic fungus Candida albicans is the leading cause of vulvovaginal candidiasis (VVC). VVC represents a major quality-of-life issue for women during their reproductive years, a stage of life where the vaginal epithelium is subject to periodic hormonally induced changes associated with menstruation and concomitant exposure to serum as well as potential intermittent contact with seminal fluid. Seminal fluid potently triggers Candida albicans to switch from yeastlike to filamentous modes of growth, a developmental response tightly linked to virulence. Conversely, vaginal fluid inhibits filamentation. Here, we used artificial formulations of seminal and vaginal fluids that faithfully mimic genuine fluids to assess the contribution of individual components within these fluids to filamentation. The high levels of albumin, amino acids, and N-acetylglucosamine in seminal fluid act synergistically as potent inducers of filamentous growth, even at atmospheric levels of CO2 and reduced temperatures (30°C). Using a simplified in vitro model that mimics the natural introduction of seminal fluid into the vulvovaginal environment, a pulse of artificial seminal fluid (ASF) was found to exert an enduring potential to overcome the inhibitory efficacy of artificial vaginal fluid (AVF) on filamentation. These findings suggest that a transient but substantial change in the nutrient levels within the vulvovaginal environment during unprotected coitus can induce resident C. albicans cells to engage developmental programs associated with virulent growth. PMID:25662979

  15. Ibuprofen reverts antifungal resistance on Candida albicans showing overexpression of CDR genes.

    PubMed

    Ricardo, Elisabete; Costa-de-Oliveira, Sofia; Dias, Ana Silva; Guerra, José; Rodrigues, Acácio Gonçalves; Pina-Vaz, Cidália

    2009-06-01

    Several mechanisms may be associated with Candida albicans resistance to azoles. Ibuprofen was described as being able to revert resistance related to efflux activity in Candida. The aim of this study was to uncover the molecular base of antifungal resistance in C. albicans clinical strains that could be reverted by ibuprofen. Sixty-two clinical isolates and five control strains of C. albicans were studied: the azole susceptibility phenotype was determined according to the Clinical Laboratory for Standards Institute, M27-A2 protocol and minimal inhibitory concentration values were recalculated with ibuprofen (100 microg mL(-1)); synergistic studies between fluconazole and FK506, a Cdr1p inhibitor, were performed using an agar disk diffusion assay and were compared with ibuprofen results. Gene expression was quantified by real-time PCR, with and without ibuprofen, regarding CDR1, CDR2, MDR1, encoding for efflux pumps, and ERG11, encoding for azole target protein. A correlation between susceptibility phenotype and resistance gene expression profiles was determined. Ibuprofen and FK506 showed a clear synergistic effect when combined with fluconazole. Resistant isolates reverting to susceptible after incubation with ibuprofen showed CDR1 and CDR2 overexpression especially of the latter. Conversely, strains that did not revert displayed a remarkable increase in ERG11 expression along with CDR genes. Ibuprofen did not alter resistance gene expression significantly (P>0.05), probably acting as a Cdrp blocker. PMID:19416368

  16. Population Structure of Candida albicans from Three Teaching Hospitals in Ghana.

    PubMed

    Adjapong, Gloria; Hale, Marie; Garrill, Ashley

    2016-02-01

    Previous studies on Candida species in a clinical setting in Ghana have shown a prevalence of Candida albicans. Despite this, very little is known about the various strain types and their population genetic structure. In this study three microsatellite loci, CAI, CAIII and CAVI, were used to investigate the population genetic structure of C. albicans from clinical isolates in Ghana. In all, 240 clinically unrelated C. albicans isolates were recovered from patients reporting at three teaching hospitals. All the isolates were heterozygous for at least one of the three loci, except for one isolate, which was homozygous for all three loci. Sixty-seven unique alleles and 240 different genotypes were generated by the three polymorphic microsatellite loci, resulting in a very high discriminatory potential of approximately 0.98. There was no significant difference in allele frequencies from the small number of anatomical sites sampled, regardless of the host conditions although high genotypic diversities were observed among the isolates. There was evidence for clonal reproduction, including over-expression of observed heterozygotes across the populations. The populations deviated significantly from Hardy-Weinberg equilibrium and pair-wise genotypic linkage disequilibria comparisons across the three loci were significant, also suggesting a clonal population. The overall Wright FIS for the three loci was negative, and the overall FST value was not significantly different from zero for the three loci analyzed, indicating a clonal and homogeneous population across the three sampling locations from Ghana. PMID:26483431

  17. CO(2) acts as a signalling molecule in populations of the fungal pathogen Candida albicans.

    PubMed

    Hall, Rebecca A; De Sordi, Luisa; Maccallum, Donna M; Topal, Hüsnü; Eaton, Rebecca; Bloor, James W; Robinson, Gary K; Levin, Lonny R; Buck, Jochen; Wang, Yue; Gow, Neil A R; Steegborn, Clemens; Mühlschlegel, Fritz A

    2010-01-01

    When colonising host-niches or non-animated medical devices, individual cells of the fungal pathogen Candida albicans expand into significant biomasses. Here we show that within such biomasses, fungal metabolically generated CO(2) acts as a communication molecule promoting the switch from yeast to filamentous growth essential for C. albicans pathology. We find that CO(2)-mediated intra-colony signalling involves the adenylyl cyclase protein (Cyr1p), a multi-sensor recently found to coordinate fungal responses to serum and bacterial peptidoglycan. We further identify Lys 1373 as essential for CO(2)/bicarbonate regulation of Cyr1p. Disruption of the CO(2)/bicarbonate receptor-site interferes selectively with C. albicans filamentation within fungal biomasses. Comparisons between the Drosophila melanogaster infection model and the mouse model of disseminated candidiasis, suggest that metabolic CO(2) sensing may be important for initial colonisation and epithelial invasion. Our results reveal the existence of a gaseous Candida signalling pathway and its molecular mechanism and provide insights into an evolutionary conserved CO(2)-signalling system. PMID:21124988

  18. Genome-Wide Transposon Mutagenesis in Saccharomyces cerevisiae and Candida albicans

    PubMed Central

    Xu, Tao; Bharucha, Nikë; Kumar, Anuj

    2016-01-01

    Transposon mutagenesis is an effective method for generating large sets of random mutations in target DNA, with applicability toward numerous types of genetic screens in prokaryotes, single-celled eukaryotes, and metazoans alike. Relative to methods of random mutagenesis by chemical/UV treatment, transposon insertions can be easily identified in mutants with phenotypes of interest. The construction of transposon insertion mutants is also less labor-intensive on a genome-wide scale than methods for targeted gene replacement, although transposon insertions are not precisely targeted to a specific residue, and thus coverage of the target DNA can be problematic. The collective advantages of transposon mutagenesis have been well demonstrated in studies of the budding yeast Saccharomyces cerevisiae and the related pathogenic yeast Candida albicans, as transposon mutagenesis has been used extensively for phenotypic screens in both yeasts. Consequently, we present here protocols for the generation and utilization of transposon-insertion DNA libraries in S. cerevisiae and C. albicans. Specifically, we present methods for the large-scale introduction of transposon insertion alleles in a desired strain of S. cerevisiae. Methods are also presented for transposon mutagenesis of C. albicans, encompassing both the construction of the plasmid-based transposon-mutagenized DNA library and its introduction into a desired strain of Candida. In total, these methods provide the necessary information to implement transposon mutagenesis in yeast, enabling the construction of large sets of identifiable gene disruption mutations, with particular utility for phenotypic screening in nonstandard genetic backgrounds. PMID:21815095

  19. Role of Toll-like receptors in systemic Candida albicans infections.

    PubMed

    Luisa Gil, Maria; Murciano, Celia; Yáñez, Alberto; Gozalbo, Daniel

    2016-01-01

    Toll-like receptors (TLRs) constitute a family of pattern-recognition receptors (PRRs) that recognize molecular signatures of microbial pathogens and function as sensors for infection. Recognition of Candida albicans by TLRs on mature immune cells, such as phagocytic cells, activates intracellular signalling pathways that trigger production of proinflammatory cytokines which are critical for innate host defence and orchestrate the adaptive response. TLR2, and TLR4 in a minor extent, recognize cell wall-associated ligands; endosomal TLR9 and TLR7 recognize DNA and RNA respectively. Interaction of C. albicans with TLRs is a complex process, as TLRs may collaborate with other PRRs and expression of surface-associated fungal ligands depends on the strain and the morphotype (yeasts or hyphae), thus defining the final induced adaptive response (Th1/Th2/Th17). TLRs are also expressed on hematopoietic stem and progenitor cells (HSPCs) where they may play a role in modulating hematopoiesis; engagement of TLR2 induces, upon recognition of C. albicans, the differentiation of HSPCs towards specific subsets of mature myeloid cells. This has opened a new perspective for anti-Candida immunointervention. PMID:26709773

  20. Candida albicans and Pseudomonas aeruginosa Interaction, with Focus on the Role of Eicosanoids

    PubMed Central

    Fourie, Ruan; Ells, Ruan; Swart, Chantel W.; Sebolai, Olihile M.; Albertyn, Jacobus; Pohl, Carolina H.

    2016-01-01

    Candida albicans is commonly found in mixed infections with Pseudomonas aeruginosa, especially in the lungs of cystic fibrosis (CF) patients. Both of these opportunistic pathogens are able to form resistant biofilms and frequently infect immunocompromised individuals. The interaction between these two pathogens, which includes physical interaction as well as secreted factors, is mainly antagonistic. In addition, research suggests considerable interaction with their host, especially with immunomodulatory lipid mediators, termed eicosanoids. Candida albicans and Pseudomonas aeruginosa are both able to utilize arachidonic acid (AA), liberated from the host cells during infection, to form eicosanoids. The production of these eicosanoids, such as Prostaglandin E2, by the host and the pathogens may affect the dynamics of polymicrobial infection and the outcome of infections. It is of considerable importance to elucidate the role of host-produced, as well as pathogen-produced eicosanoids in polymicrobial infection. This review will focus on in vitro as well as in vivo interaction between C. albicans and P. aeruginosa, paying special attention to the role of eicosanoids in the cross-talk between host and the pathogens. PMID:26955357

  1. Effects of Mentha suaveolens Essential Oil Alone or in Combination with Other Drugs in Candida albicans

    PubMed Central

    Stringaro, Annarita; Vavala, Elisabetta; Pepi, Federico; Mignogna, Giuseppina; Garzoli, Stefania; Angiolella, Letizia

    2014-01-01

    Candidosis is the most important cause of fungal infections in humans. The yeast Candida albicans can form biofilms, and it is known that microbial biofilms play an important role in human diseases and are very difficult to treat. The prolonged treatment with drugs has often resulted in failure and resistance. Due to the emergence of multidrug resistance, alternatives to conventional antimicrobial therapy are needed. This study aims to analyse the effects induced by essential oil of Mentha suaveolens Ehrh (EOMS) on Candida albicans and its potential synergism when used in combination with conventional drugs. Morphological differences between control and EOMS treated yeast cells or biofilms were observed by scanning electron microscopy and transmission electron microscopy (SEM and TEM resp.,). In order to reveal the presence of cell cycle alterations, flow cytometry analysis was carried out as well. The synergic action of EOMS was studied with the checkerboard method, and the cellular damage induced by different treatments was analysed by TEM. The results obtained have demonstrated both the effects of EOMS on C. albicans yeast cells and biofilms and the synergism of EOMS when used in combination with conventional antifungal drugs as fluconazole (FLC) and micafungin (MCFG), and therefore we can hypothesize on its potential use in therapy. Further studies are necessary to know its mechanism of action. PMID:24719638

  2. Production and function of cytokines in natural and acquired immunity to Candida albicans infection.

    PubMed Central

    Ashman, R B; Papadimitriou, J M

    1995-01-01

    Host resistance against infections caused by the yeast Candida albicans is mediated predominantly by polymorphonuclear leukocytes and macrophages. Antigens of Candida stimulate lymphocyte proliferation and cytokine synthesis, and in both humans and mice, these cytokines enhance the candidacidal functions of the phagocytic cells. In systemic candidiasis in mice, cytokine production has been found to be a function of the CD4+ T helper (Th) cells. The Th1 subset of these cells, characterized by the production of gamma interferon and interleukin-2, is associated with macrophage activation and enhanced resistance against reinfection, whereas the Th2 subset, which produces interleukins-4, -6, and -10, is linked to the development of chronic disease. However, other models have generated divergent data. Mucosal infection generally elicits Th1-type cytokine responses and protection from systemic challenge, and identification of cytokine mRNA present in infected tissues of mice that develop mild or severe lesions does not show pure Th1- or Th2-type responses. Furthermore, antigens of C. albicans, mannan in particular, can induce suppressor cells that modulate both specific and nonspecific cellular and humoral immune responses, and there is an emerging body of evidence that molecular mimicry may affect the efficiency of anti-Candida responses within defined genetic contexts. PMID:8531890

  3. Th17 cells confer long-term adaptive immunity to oral mucosal Candida albicans infections.

    PubMed

    Hernández-Santos, N; Huppler, A R; Peterson, A C; Khader, S A; McKenna, K C; Gaffen, S L

    2013-09-01

    Oropharyngeal candidiasis (OPC) is an opportunistic infection caused by Candida albicans. Despite its prevalence, little is known about C. albicans-specific immunity in the oral mucosa. Vaccines against Candida generate both T helper type 1 (Th1) and Th17 responses, and considerable evidence implicates interleukin (IL)-17 in immunity to OPC. However, IL-17 is also produced by innate immune cells that are remarkably similar to Th17 cells, expressing the same markers and localizing to similar mucosal sites. To date, the relative contribution(s) of Th1, Th17, and innate IL-17-producing cells in OPC have not been clearly defined. Here, we sought to determine the nature and function of adaptive T-cell responses to OPC, using a new recall infection model. Mice subjected to infection and re-challenge with Candida mounted a robust and stable antigen-specific IL-17 response in CD4+ but not CD8+ T cells. There was little evidence for Th1 or Th1/Th17 responses. The Th17 response promoted accelerated fungal clearance, and Th17 cells could confer protection in Rag1-/- mice upon adoptive transfer. Surprisingly, CD4 deficiency did not cause OPC but was instead associated with compensatory IL-17 production by Tc17 and CD3+CD4-CD8- cells. Therefore, classic CD4+Th17 cells protect from OPC but can be compensated by other IL-17-producing cells in CD4-deficient hosts. PMID:23250275

  4. Cellular Structural Changes in Candida albicans Caused by the Hydroalcoholic Extract from Sapindus saponaria L.

    PubMed

    Shinobu-Mesquita, Cristiane S; Bonfim-Mendonça, Patricia S; Moreira, Amanda L; Ferreira, Izabel C P; Donatti, Lucelia; Fiorini, Adriana; Svidzinski, Terezinha I E

    2015-01-01

    Vulvovaginal candidiasis (VVC) is a disease caused by the abnormal growth of yeast-like fungi in the mucosa of the female genital tract. Candida albicans is the principal etiological agent involved in VVC, but reports have shown an increase in the prevalence of Candida non-C. albicans (CNCA) cases, which complicates VVC treatment because CNCA does not respond well to antifungal therapy. Our group has reported the in vitro antifungal activity of extracts from Sapindus saponaria L. The present study used scanning electron microscopy and transmission electron microscopy to further evaluate the antifungal activity of hydroalcoholic extract from S. saponaria (HE) against yeast obtained from VVC and structural changes induced by HE. We observed the antifungal activity of HE against 125 vaginal yeasts that belonged to four different species of the Candida genus and S. cerevisae. The results suggest that saponins that are present in HE act on the cell wall or membrane of yeast at the first moments after contact, causing damage to these structures and cell lysis. PMID:26007191

  5. Azole Drugs Are Imported By Facilitated Diffusion in Candida albicans and Other Pathogenic Fungi

    PubMed Central

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

    2010-01-01

    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 Km of 0.64 uM and Vmax 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. PMID:20941354

  6. Evolution and replacement of Candida albicans strains during recurrent vaginitis demonstrated by DNA fingerprinting.

    PubMed Central

    Schröppel, K; Rotman, M; Galask, R; Mac, K; Soll, D R

    1994-01-01

    Southern blot hybridization with the Ca3 probe and the C fragment of the Ca3 probe was used to assess the genetic relatedness of Candida albicans strains from one patient with recurrent C. albicans infection in whom the same strain was maintained, one patient in whom the infecting strain was replaced, and their male sexual partners. In the patient in whom the infecting strain was maintained, the infecting strain exhibited a minor genetic change in each successive episode of Candida vaginitis. These genetic changes occurred in the C-fragment bands of the Ca3 hybridization pattern. In the patient in whom the infecting strain was replaced by another infecting strain, a transition infection involved a genetically mixed infecting population, and the replacement strain appeared to have originated from the oral cavity of the male partner. The results demonstrate that the infecting strains of recurrent Candida vaginitis are not genetically stable, that drug treatment can result in the selection of variants of the previously infecting strain or replacement by a genetically unrelated strain, and that the male partner can be the source of a replacement strain. Images PMID:7852550

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

    PubMed

    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

  8. 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

  9. Synthesis, morphology and antifungal activity of nano-particulated amphotericin-B, ketoconazole and thymoquinone against Candida albicans yeasts and Candida biofilm.

    PubMed

    Randhawa, Mohammad A; Gondal, Mohammed A; Al-Zahrani, Al-Hosain J; Rashid, Siddique G; Ali, Ashraf

    2015-01-01

    In the current study, nano-particulated drugs-Amphotericin-B, Ketoconazole and Thymoquinone (an active ingredient of Nigella sativa)-were prepared using the ball milling technique, and their particle sizes were examined by transmission electron microscopy (TEM) and using a particle size analyzer. The grain sizes of the prepared compounds were found in between 5 to 20 nm, and exhibited quasi-spherical morphology. The antifungal activity of each nano-particulated drug was investigated in vitro against Candida albicans yeasts and Candida biofilm, and compared with their micro-structured conventional forms. Nano-sized drugs were found to be two to four times more effective in disinfecting both the Candida yeasts and Candida biofilm. The study is a first of its kind as nano-forms of drugs have not been studied against Candida and Candida biofilm before. Further investigations are required for the determination of the clinical significance of the nano-formulation of antifungal substances. PMID:25560257

  10. Rapid Detection of Candida albicans by Polymerase Spiral Reaction Assay in Clinical Blood Samples

    PubMed Central

    Jiang, Xiaoqun; Dong, Derong; Bian, Lihong; Zou, Dayang; He, Xiaoming; Ao, Da; Yang, Zhan; Huang, Simo; Liu, Ningwei; Liu, Wei; Huang, Liuyu

    2016-01-01

    Candida albicans is the most common human yeast pathogen which causes mucosal infections and invasive fungal diseases. Early detection of this pathogen is needed to guide preventative and therapeutic treatment. The aim of this study was to establish a polymerase spiral reaction (PSR) assay that rapidly and accurately detects C. albicans and to assess the clinical applicability of PSR-based diagnostic testing. Internal transcribed spacer 2 (ITS2), a region between 5.8S and 28S fungal ribosomal DNA, was used as the target sequence. Four primers were designed for amplification of ITS2 with the PSR method, which was evaluated using real time turbidity monitoring and visual detection using a pH indicator. Fourteen non-C. albicans yeast strains were negative for detection, which indicated the specificity of PSR assay was 100%. A 10-fold serial dilution of C. albicans genomic DNA was subjected to PSR and conventional polimerase chain reaction (PCR) to compare their sensitivities. The detection limit of PSR was 6.9 pg/μl within 1 h, 10-fold higher than that of PCR (69.0 pg/μl). Blood samples (n = 122) were collected from intensive care unit and hematological patients with proven or suspected C. albicans infection at two hospitals in Beijing, China. Both PSR assay and the culture method were used to analyze the samples. Of the 122 clinical samples, 34 were identified as positive by PSR. The result was consistent with those obtained by the culture method. In conclusion, a novel and effective C. albicans detection assay was developed that has a great potential for clinical screening and point-of-care testing. PMID:27379048

  11. In Vitro and In Vivo Antifungal Activity of Lichochalcone-A against Candida albicans Biofilms

    PubMed Central

    Seleem, Dalia; Benso, Bruna; Noguti, Juliana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2016-01-01

    Oral candidiasis (OC) is an opportunistic fungal infection with high prevalence among immunocompromised patients. Candida albicans is the most common fungal pathogen responsible for OC, often manifested in denture stomatitis and oral thrush. Virulence factors, such as biofilms formation and secretion of proteolytic enzymes, are key components in the pathogenicity of C. albicans. Given the limited number of available antifungal therapies and the increase in antifungal resistance, demand the search for new safe and effective antifungal treatments. Lichochalcone-A is a polyphenol natural compound, known for its broad protective activities, as an antimicrobial agent. In this study, we investigated the antifungal activity of lichochalcone-A against C. albicans biofilms both in vitro and in vivo. Lichochalcone-A (625 μM; equivalent to 10x MIC) significantly reduced C. albicans (MYA 2876) biofilm growth compared to the vehicle control group (1% ethanol), as indicated by the reduction in the colony formation unit (CFU)/ml/g of biofilm dry weight. Furthermore, proteolytic enzymatic activities of proteinases and phospholipases, secreted by C. albicans were significantly decreased in the lichochalcone-A treated biofilms. In vivo model utilized longitudinal imaging of OC fungal load using a bioluminescent-engineered C. albicans (SKCa23-ActgLUC) and coelenterazine substrate. Mice treated with lichochalcone-A topical treatments exhibited a significant reduction in total photon flux over 4 and 5 days post-infection. Similarly, ex vivo analysis of tongue samples, showed a significant decrease in CFU/ml/mg in tongue tissue sample of lichochalcone-A treated group, which suggest the potential of lichochalcone-A as a novel antifungal agent for future clinical use. PMID:27284694

  12. In Vitro and In Vivo Activities of Pterostilbene against Candida albicans Biofilms

    PubMed Central

    Li, De-Dong; Zhao, Lan-Xue; Mylonakis, Eleftherios; Hu, Gan-Hai; Zou, Yong; Huang, Tong-Kun; Yan, Lan

    2014-01-01

    Pterostilbene (PTE) is a stilbene-derived phytoalexin that originates from several natural plant sources. In this study, we evaluated the activity of PTE against Candida albicans biofilms and explored the underlying mechanisms. In 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assays, biofilm biomass measurement, confocal laser scanning microscopy, and scanning electron microscopy, we found that ≤16 μg/ml PTE had a significant effect against C. albicans biofilms in vitro, while it had no fungicidal effect on planktonic C. albicans cells, which suggested a unique antibiofilm effect of PTE. Then we found that PTE could inhibit biofilm formation and destroy the maintenance of mature biofilms. At 4 μg/ml, PTE decreased cellular surface hydrophobicity (CSH) and suppressed hyphal formation. Gene expression microarrays and real-time reverse transcription-PCR showed that exposure of C. albicans to 16 μg/ml PTE altered the expression of genes that function in morphological transition, ergosterol biosynthesis, oxidoreductase activity, and cell surface and protein unfolding processes (heat shock proteins). Filamentation-related genes, especially those regulated by the Ras/cyclic AMP (cAMP) pathway, including ECE1, ALS3, HWP1, HGC1, and RAS1 itself, were downregulated upon PTE treatment, indicating that the antibiofilm effect of PTE was related to the Ras/cAMP pathway. Then, we found that the addition of exogenous cAMP reverted the PTE-induced filamentous growth defect. Finally, with a rat central venous catheter infection model, we confirmed the in vivo activity of PTE against C. albicans biofilms. Collectively, PTE had strong activities against C. albicans biofilms both in vitro and in vivo, and these activities were associated with the Ras/cAMP pathway. PMID:24514088

  13. Assessment of antifungal activity of herbal and conventional toothpastes against clinical isolates of Candida albicans

    PubMed Central

    Adwan, Ghaleb; Salameh, Yousef; Adwan, Kamel; Barakat, Ali

    2012-01-01

    Objective To detect the anticandidal activity of nine toothpastes containing sodium fluoride, sodium monofluorophosphate and herbal extracts as an active ingredients against 45 oral and non oral Candida albicans (C. albicans) isolates. Methods The antifungal activity of these toothpaste formulations was determined using a standard agar well diffusion method. Statistical analysis was performed using a statistical package, SPSS windows version 15, by applying mean values using one-way ANOVA with post-hoc least square differences (LSD) method. A P value of less than 0.05 was considered significant. Results All toothpastes studied in our experiments were effective in inhibiting the growth of all C. albicans isolates. The highest anticandidal activity was obtained from toothpaste that containing both herbal extracts and sodium fluoride as active ingredients, while the lowest activity was obtained from toothpaste containing sodium monofluorophosphate as an active ingredient. Antifungal activity of Parodontax toothpaste showed a significant difference (P< 0.001) against C. albicans isolates compared to toothpastes containing sodium fluoride or herbal products. Conclusions In the present study, it has been demonstrated that toothpaste containing both herbal extracts and sodium fluoride as active ingredients are more effective in control of C. albicans, while toothpaste that containing monofluorophosphate as an active ingredient is less effective against C. albicans. Some herbal toothpaste formulations studied in our experiments, appear to be equally effective as the fluoride dental formulations and it can be used as an alternative to conventional formulations for individuals who have an interest in naturally-based products. Our results may provide invaluable information for dental professionals. PMID:23569933

  14. In Vitro and In Vivo Antifungal Activity of Lichochalcone-A against Candida albicans Biofilms.

    PubMed

    Seleem, Dalia; Benso, Bruna; Noguti, Juliana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2016-01-01

    Oral candidiasis (OC) is an opportunistic fungal infection with high prevalence among immunocompromised patients. Candida albicans is the most common fungal pathogen responsible for OC, often manifested in denture stomatitis and oral thrush. Virulence factors, such as biofilms formation and secretion of proteolytic enzymes, are key components in the pathogenicity of C. albicans. Given the limited number of available antifungal therapies and the increase in antifungal resistance, demand the search for new safe and effective antifungal treatments. Lichochalcone-A is a polyphenol natural compound, known for its broad protective activities, as an antimicrobial agent. In this study, we investigated the antifungal activity of lichochalcone-A against C. albicans biofilms both in vitro and in vivo. Lichochalcone-A (625 μM; equivalent to 10x MIC) significantly reduced C. albicans (MYA 2876) biofilm growth compared to the vehicle control group (1% ethanol), as indicated by the reduction in the colony formation unit (CFU)/ml/g of biofilm dry weight. Furthermore, proteolytic enzymatic activities of proteinases and phospholipases, secreted by C. albicans were significantly decreased in the lichochalcone-A treated biofilms. In vivo model utilized longitudinal imaging of OC fungal load using a bioluminescent-engineered C. albicans (SKCa23-ActgLUC) and coelenterazine substrate. Mice treated with lichochalcone-A topical treatments exhibited a significant reduction in total photon flux over 4 and 5 days post-infection. Similarly, ex vivo analysis of tongue samples, showed a significant decrease in CFU/ml/mg in tongue tissue sample of lichochalcone-A treated group, which suggest the potential of lichochalcone-A as a novel antifungal agent for future clinical use. PMID:27284694

  15. Rapid Detection of Candida albicans by Polymerase Spiral Reaction Assay in Clinical Blood Samples.

    PubMed

    Jiang, Xiaoqun; Dong, Derong; Bian, Lihong; Zou, Dayang; He, Xiaoming; Ao, Da; Yang, Zhan; Huang, Simo; Liu, Ningwei; Liu, Wei; Huang, Liuyu

    2016-01-01

    Candida albicans is the most common human yeast pathogen which causes mucosal infections and invasive fungal diseases. Early detection of this pathogen is needed to guide preventative and therapeutic treatment. The aim of this study was to establish a polymerase spiral reaction (PSR) assay that rapidly and accurately detects C. albicans and to assess the clinical applicability of PSR-based diagnostic testing. Internal transcribed spacer 2 (ITS2), a region between 5.8S and 28S fungal ribosomal DNA, was used as the target sequence. Four primers were designed for amplification of ITS2 with the PSR method, which was evaluated using real time turbidity monitoring and visual detection using a pH indicator. Fourteen non-C. albicans yeast strains were negative for detection, which indicated the specificity of PSR assay was 100%. A 10-fold serial dilution of C. albicans genomic DNA was subjected to PSR and conventional polimerase chain reaction (PCR) to compare their sensitivities. The detection limit of PSR was 6.9 pg/μl within 1 h, 10-fold higher than that of PCR (69.0 pg/μl). Blood samples (n = 122) were collected from intensive care unit and hematological patients with proven or suspected C. albicans infection at two hospitals in Beijing, China. Both PSR assay and the culture method were used to analyze the samples. Of the 122 clinical samples, 34 were identified as positive by PSR. The result was consistent with those obtained by the culture method. In conclusion, a novel and effective C. albicans detection assay was developed that has a great potential for clinical screening and point-of-care testing. PMID:27379048

  16. Microsatellite typing identifies the major clades of the human pathogen Candida albicans.

    PubMed

    Chávez-Galarza, Julio; Pais, Célia; Sampaio, Paula

    2010-07-01

    Candida albicans population studies showed that this species could be divided into sub-groups of closely related strains, designated by clades. Since the emergence of microsatellite analysis as a PCR based method, this technique has been successfully used as a tool to differentiate C. albicans isolates but has never been tested regarding clustering of the five major clades. In this study we tested microsatellite length polymorphism (MLP) ability to group 29 C. albicans strains previously defined as belonging to clades I, II, III, E and SA, nine atypical strains from Angola and Madagascar, and 78 Portuguese clinical isolates. MLP typing of the total 116 strains analyzed yielded 87 different multilocus allelic combinations which resulted in a high discriminatory power index, of 0.987, with only two markers, CA1 and CEF3. Cluster analysis of the 29 previously defined strains grouped them according to their clade designation with a matrix cophenetic correlation of r=0.963 after a normalized Mantel statistic. Clustering analysis of the 116 strains maintained the same groupings, clearly defining the five major C. albicans clades. The cophenetic value obtained was of r=0.839, and the one-tail probability of the normalized Mantel statistic out of 1000 random permutations was P=0.0020. The proportion of Portuguese isolates in the groups I, II, III and SA was of 2.7%, 15.4%, 3.8% and 0%, respectively. None of the isolates co-clustered with the atypical strains. These results confirm MLP typing as a good method both to type and differentiate C. albicans isolates and to group isolates, identifying the major C. albicans clades, similarly to Ca3 fingerprinting and multilocus sequence typing (MLST). PMID:20348035

  17. Staphylococcus aureus adherence to Candida albicans hyphae is mediated by the hyphal adhesin Als3p

    PubMed Central

    Peters, Brian M.; Ovchinnikova, Ekaterina S.; Krom, Bastiaan P.; Schlecht, Lisa Marie; Zhou, Han; Hoyer, Lois L.; Busscher, Henk J.; van der Mei, Henny C.; Jabra-Rizk, Mary Ann

    2012-01-01

    The bacterium Staphylococcus (St.) aureus and the opportunistic fungus Candida albicans are currently among the leading nosocomial pathogens, often co-infecting critically ill patients, with high morbidity and mortality. Previous investigations have demonstrated preferential adherence of St. aureus to C. albicans hyphae during mixed biofilm growth. In this study, we aimed to characterize the mechanism behind this observed interaction. C. albicans adhesin-deficient mutant strains were screened by microscopy to identify the specific receptor on C. albicans hyphae recognized by St. aureus. Furthermore, an immunoassay was developed to validate and quantify staphylococcal binding to fungal biofilms. The findings from these experiments implicated the C. albicans adhesin agglutinin-like sequence 3 (Als3p) in playing a major role in the adherence process. This association was quantitatively established using atomic force microscopy, in which the adhesion force between single cells of the two species was significantly reduced for a C. albicans mutant strain lacking als3. Confocal microscopy further confirmed these observations, as St. aureus overlaid with a purified recombinant Als3 N-terminal domain fragment (rAls3p) exhibited robust binding. Importantly, a strain of Saccharomyces cerevisiae heterologously expressing Als3p was utilized to further confirm this adhesin as a receptor for St. aureus. Although the parental strain does not bind bacteria, expression of Als3p on the cell surface conferred upon the yeast the ability to strongly bind St. aureus. To elucidate the implications of these in vitro findings in a clinically relevant setting, an ex vivo murine model of co-infection was designed using murine tongue explants. Fluorescent microscopic images revealed extensive hyphal penetration of the epithelium typical of C. albicans mucosal infection. Interestingly, St. aureus bacterial cells were only seen within the epithelial tissue when associated with the invasive

  18. Binding Force Dynamics of Streptococcus mutans-glucosyltransferase B to Candida albicans.

    PubMed

    Hwang, G; Marsh, G; Gao, L; Waugh, R; Koo, H

    2015-09-01

    Candida albicans cells are often detected with Streptococcus mutans in plaque biofilms from children affected with early childhood caries. The coadhesion between these 2 organisms appears to be largely mediated by the S. mutans-derived exoenzyme glucosyltransferase B (GtfB); GtfB readily binds to C. albicans cells in an active form, producing glucans locally that provide enhanced binding sites for S. mutans. However, knowledge is limited about the mechanisms by which the bacterial exoenzyme binds to and functions on the fungal surface to promote this unique cross-kingdom interaction. In this study, we use atomic force microscopy to understand the strength and binding dynamics modulating GtfB-C. albicans adhesive interactions in situ. Single-molecule force spectroscopy with GtfB-functionalized atomic force microscopy tips demonstrated that the enzyme binds with remarkable strength to the C. albicans cell surface (~2 nN) and showed a low dissociation rate, suggesting a highly stable bond. Strikingly, the binding strength of GtfB to the C. albicans surface was ~2.5-fold higher and the binding stability, ~20 times higher, as compared with the enzyme adhesion to S. mutans. Furthermore, adhesion force maps showed an intriguing pattern of GtfB binding. GtfB adhered heterogeneously on the surface of C. albicans, showing a higher frequency of adhesion failure but large sections of remarkably strong binding forces, suggesting the presence of GtfB binding domains unevenly distributed on the fungal surface. In contrast, GtfB bound uniformly across the S. mutans cell surface with less adhesion failure and a narrower range of binding forces (vs. the C. albicans surface). The data provide the first insights into the mechanisms underlying the adhesive and mechanical properties governing GtfB interactions with C. albicans. The strong and highly stable GtfB binding to C. albicans could explain, at least in part, why this bacterially derived exoenzyme effectively modulates this

  19. Drug Susceptibility of Matrix-Encapsulated Candida albicans Nano-Biofilms

    PubMed Central

    Srinivasan, Anand; Gupta, Celia Macias; Agrawal, C. Mauli; Leung, Kai P.; Lopez-Ribot, Jose L.; Ramasubramanian, Anand K.

    2015-01-01

    The rise in the use of biomedical devices and implants has seen a concomitant surge in the advent of device-related nosocomial (hospital-acquired) infections of bacterial and fungal origins. The most common nosocomial fungal infection is candidiasis caused mainly by Candida albicans biofilms. Candidiasis is associated with an unacceptably high mortality rate, and there is an urgent need for the discovery of new antifungal drugs that prevent or control biofilm formation. To this end, we recently developed an ultra-high-throughput microarray platform consisting of nano-scale biofilms of C. albicans encapsulated in collagen or alginate hydrogel matrices for antifungal drug screening. Here, we report that the choice of matrix influences the apparent susceptibility of C. albicans to the common anti-fungal drugs, amphotericin B and caspofungin. While amphotericin B is equally effective against biofilms grown in collagen and alginate matrices, caspofungin is effective only against biofilms grown only in alginate, but not in collagen. We demonstrate differences in the distribution of the drugs in the two matrices may contribute to the susceptibility of C. albicans nano-biofilms. In a larger context, our results highlight the importance of the choice of matrix as a parameter in 3D cell encapsulation, and suggest a screening strategy to predict drug performance in vivo. PMID:24114441

  20. Candida albicans Shed Msb2 and Host Mucins Affect the Candidacidal Activity of Salivary Hst 5

    PubMed Central

    Puri, Sumant; Friedman, Justin; Saraswat, Darpan; Kumar, Rohitashw; Li, Rui; Ruszaj, Donna; Edgerton, Mira

    2015-01-01

    Salivary Histatin 5 (Hst 5) is an antimicrobial peptide that exhibits potent antifungal activity towards Candida albicans, the causative agent of oral candidiasis. However, it exhibits limited activity in vivo, largely due to inactivation by salivary components of both host and pathogen origin. Proteins secreted by C. albicans during infection such as secreted aspartyl proteases (Saps) and shed mucin Msb2 can reduce Hst 5 activity; and human salivary mucins, while suggested to protect Hst 5 from proteolytic degradation, can entrap peptides into mucin gels, thereby reducing bioavailability. We show here that Sap6 that is secreted during hyphal growth reduces Hst 5 activity, most likely a result of proteolytic degradation of Hst 5 since this effect is abrogated with heat inactivated Sap 6. We further show that just like C. albicans shedding Msb2, mammalian mucins, fetuin and porcine gut mucin (that is related to salivary mucins), also reduce Hst 5 activity. However, we identify mucin-like protein-induced changes in C. albicans cell morphology and aggregation patterns, suggesting that the effect of such proteins on Hst 5 cannot be interpreted independently of their effect on yeast cells. PMID:26529023

  1. Comparison of the in vitro Effect of Chemical and Herbal Mouthwashes on Candida albicans

    PubMed Central

    Talebi, Somayeh; Sabokbar, Azar; Riazipour, Majid; Saffari, Mohsen

    2014-01-01

    Background: During the recent decades research has focused to find scientific evidence for the effects of herbal medicines. Researchers are interested in herbal remedies for medication and aim to substitute herbal material instead of chemical formula with limited side effects for human being. Objectives: The aim of the current study was to compare the in vitro effect of herbal and chemical mouthwashes against Candida albicans. Materials and Methods: In this research, we used a standard strain of C. albicans, PTCC 5027. The suspension was made by a fresh culture of C. albicans (24 hours) and the optical density (turbidity equating to a McFarland standard of 0.5) was read at 530 nm. The C. albicans suspension was cultured on Sabouraud dextrose agar plate. Next, two wells were filled with mouthwashes and after incubation at 30ºC for 24 hours, the inhibition zone was measured. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of mouthwashes were determined. Data were analyzed using the SPSS software, independent T-tests and one-sided variance analysis (ANOVA-one way). Results: Based on these findings on agar diffusion with (P = 0.764), MIC and MFC tests (P = 0.879), there were no significant differences between the antifungal effect of herbal and chemical mouthwashes. Conclusions: This study showed that, chemical mouthwashes acted better than herbal mouthwashes and among different chemical mouthwashes, Oral B was most effective. PMID:25741429

  2. CD4+ T-helper-cell responses in mice with low-level Candida albicans infection.

    PubMed Central

    Mencacci, A; Spaccapelo, R; Del Sero, G; Enssle, K H; Cassone, A; Bistoni, F; Romani, L

    1996-01-01

    Resistance and susceptibility to Candida albicans infection have been shown to be dependent upon the activation of CD4+ T helper (Th) type 1 or Th2 cells, respectively. To study the type, kinetics, and cytokine dependency of CD4+ Th-cell responses in low-level C. albicans infection, susceptible mice were infected with sublethal doses of C. albicans and assessed for parameters of CD4+ Th-dependent immunity. Interleukin (IL)-12 and gamma interferon were always produced early in infection regardless of the pathogen load. In contrast, production of IL-4, and hence Th2-cell reactivity, was strictly dose dependent, being induced at the higher dose of the fungus. Production of IL-12 correlated with a successful control of infection in mice exposed to the lower doses of C. albicans but not with the development of acquired immunity. An antigenic stimulus appeared to be required for IL-12 to induce a protective anticandidal response. Cytokine depletion in vivo revealed that neutralization of IL-4 was protective early but not late in infection, suggesting a different role for IL-4 in the induction versus maintenance of an ongoing anticandidal Th response. Late in infection, an exacerbative effect was also observed upon IL-12 neutralization. These results indicate that the fungal burden and timing of cytokine appearance greatly influence CD4+ Th induction and effector functions in mice with candidiasis. PMID:8945525

  3. Synergy Between Polyvinylpyrrolidone-Coated Silver Nanoparticles and Azole Antifungal Against Drug-Resistant Candida albicans.

    PubMed

    Sun, Lingmei; Liao, Kai; Li, Yiping; Zhao, Lei; Liang, Sai; Guo, Dan; Hu, Jun; Wang, Dayong

    2016-03-01

    In the clinical practice, resistance of Candida albicans to antifungal agents has frequently emerged. Silver-nanoparticles (Ag-NPs) have been demonstrated to have the antifungal property. We investigated the potential for synergy between polyvinylpyrrolidone (PVP)-coated Ag-NPs and azole antifungal, such as fluconazole or voriconazole, against drug-resistant C. albicans strain CA10. When antifungal agent was examined alone, fluconazole and voriconazole did not kill drug-resistant C. albicans, and PVP-coated Ag-NPs had only the moderate killing ability. In contrast, the combinational treatment of PVP-coated Ag-NPs with fluconazole or voriconazole was effective in being against the drug-resistant C. albicans. After the combinational treatment, we detected the disruption of cell membrane integrity, the tendency of PVP-coated Ag-NPs to adhere to cell membrane, and the inhibition of budding process. Moreover, after the combinational treatment, the defects in ergosterol signaling and efflux pump functions were detected. Our results suggest that the combinational use of engineered nanomaterials (ENMs), such as PVP-coated Ag-NPs, with the conventional antifungal may be a viable strategy to combat drug-resistant fungal infection. PMID:27455637

  4. Mechanisms of azole resistance in Candida albicans clinical isolates from Shanghai, China.

    PubMed

    Liu, Jin-Yan; Shi, Ce; Wang, Ying; Li, Wen-Jing; Zhao, Yue; Xiang, Ming-Jie

    2015-04-01

    This study was undertaken to characterize the mechanism(s) of azole resistance in clinical isolates of Candida albicans collected in Shanghai, China, focusing on the role of efflux pumps, target enzymes of fluconazole (Erg11), respiratory status and the ergosterol biosynthetic pathway. Clinical isolates of C. albicans (n = 30) were collected from 30 different non-HIV-infected patients in four hospitals in Shanghai. All 30 C. albicans isolates were susceptible to amphotericin B and 5-fluorocytosine. Twelve C. albicans isolates showed resistance to at least one type of triazole antifungal. Flow cytometry analysis of rhodamine 6G efflux showed that azole-resistant isolates had greater efflux pump activity, which was consistent with elevated levels of CDR1 and CDR2 genes that code for ABC efflux pumps. However, we did not observe increased expression of ERG11 and MDR1 or respiratory deficiency. Several mutations of ERG11 and TAC1 genes were detected. The F964Y mutation in the TAC1 gene was identified for the first time. Two main sterols, ergosterol and lanosterol, were identified by GC-MS chromatogram, and no missense mutations were found in ERG3. Furthermore, seven amino acid substitutions in ERG11, A114S, Y132H, Y132F, K143Q, K143R, Y257H and G448E were found, by Type II spectral quantitative analysis, to contribute to low affinity binding between Erg11 and fluconazole. PMID:25748216

  5. Fungistatic activity of all-trans retinoic acid against Aspergillus fumigatus and Candida albicans

    PubMed Central

    Campione, Elena; Gaziano, Roberta; Marino, Daniele; Orlandi, Augusto

    2016-01-01

    Purpose Fungal infections are a major complication in hematologic and neoplastic patients causing severe morbidity and mortality. Aspergillus fumigatus and Candida albicans are among the most invasive opportunistic pathogens in immunocompromised patients, and classic antifungal drugs are frequently unsuccessful in these patients. Recent reports hypothesize that the antifungal efficacy of all-trans retinoic acid (ATRA) is mainly related to its strong capacity to stimulate monocyte-mediated immunity, but no consideration was given to its potential direct fungistatic activity. Moreover, ATRA offers the opportunity for systemic therapy. Methods and results We investigated the efficacy of ATRA at different concentrations for its antifungal activity against opportunistic A. fumigatus and C. albicans obtained from clinical samples according to standard protocols. A fungistatic activity of ATRA on A. fumigatus and C. albicans at 0.5–1 mM concentration was documented up to 7 days. Conclusion This is the first evidence of a direct and strong fungistatic activity of ATRA against A. fumigatus and C. albicans. The potential adjuvant therapeutic application of ATRA might be useful in the treatment and/or prevention of systemic mycoses in immunocompromised patients. The discovery of a direct fungistatic activity, in association with its reported immunomodulatory properties, makes ATRA an excellent candidate for new combined antifungal strategies for systemic mycoses in immunocompromised and cancer patients. PMID:27199548

  6. In vitro and ex vivo assays of virulence in Candida albicans.

    PubMed

    Calderone, Richard A

    2009-01-01

    The measurement of virulence using ex vivo and in vitro models is discussed in the context of the human pathogenic yeast, Candida albicans. The models described are of two types. First, reconstituted tissues of various sorts are used that are derived from human carcinomas. The tissues are grown in vitro in complex media, attain a three-dimensional tissue structure, and retain cell-surface antigens typical of the specific tissue. Both adherence and invasion of tissues can be studied following infection with strains of C. albicans (1, 2). Further, one can increase the level of complexity by providing infected tissues with host phagocytes or cytokines such that an immune contribution to protection can be followed (3-5). The second model employs Drosophila melanogaster larvae that are infected with C. albicans (6). In this model, the progression of virulence is followed after injection of strains of a pathogen of interest into the fly abdomen. Thus, in the case of human pathogenic fungi, the recognition of host tissues and invasion by the specific pathogen can be studied in vitro and correlations developed for human disease. The obvious advantage to using animal models (e.g., mice) is reduced cost, such that large numbers of C. albicans strains can be assessed for their virulence properties. Additionally, another application of these models is in drug discovery. It is clear that there are both advantages and disadvantages of the use of alternate models other than a murine model, to evaluate disease, and this is discussed below. PMID:19152042

  7. Effect of nonylphenol on growth of Neurospora crassa and Candida albicans.

    PubMed Central

    Karley, A J; Powell, S I; Davies, J M

    1997-01-01

    The effects of the nonionic surfactant nonylphenol on the growth and morphologies of the filamentous fungus Neurospora crassa and the diploid yeast Candida albicans have been examined. Nonylphenol inhibited respiration and growth of N. crassa, effecting a 10-fold decrease in organism yield at 25 microM. Severe morphological defects were also induced: cell shape was abnormal and apical dominance was lost. Nonylphenol monoethoxylate (the parent compound of nonylphenol) was a less potent growth inhibitor and morphogen. The growth of the yeast form of C. albicans was sensitive to nonylphenol (inducing an order of magnitude decrease in specific growth rate with a 10-fold increase in dose concentration) but not nonylphenol monoethoxylate. Similarly, C. albicans ATP content was reduced and glucose-induced extracellular acidification was inhibited only by nonylphenol. Although estrogens may induce the dimorphic transition of C. albicans, nonylphenol (as an environmental estrogen mimic) failed to trigger germ tube formation under nonpermissive conditions and inhibited it under permissive conditions. The effects of nonylphenol are most readily explained as the result of uncoupling of respiration, which produces multiple physiological effects. PMID:9097428

  8. Hairpin dsRNA does not trigger RNA interference in Candida albicans cells.

    PubMed

    Staab, Janet F; White, Theodore C; Marr, Kieren A

    2011-01-01

    RNA interference/silencing mechanisms triggered by double-stranded RNA (dsRNA) have been described in many eukaryotes, including fungi. These mechanisms have in common small RNA molecules (siRNAs or microRNAs) originating from dsRNAs that, together with the effector protein Argonaute, mediate silencing. The genome of the fungal pathogen Candida albicans harbours a well-conserved Argonaute and a non-canonical Dicer, essential members of silencing pathways. Prototypical siRNAs are detected as members of the C. albicans transcriptome, which is potential evidence of RNA interference/silencing pathways in this organism. Surprisingly, expression of a dsRNA a hairpin ADE2 dsRNA molecule to interfere with the endogenous ADE2 mRNA did not result in down-regulation of the message or produce adenine auxotrophic strains. Cell free assays showed that the hairpin dsRNA was a substrate for the putative C. albicans Dicer, discounting the possibility that the nature of the dsRNA trigger affects silencing functionality. Our results suggested that unknown cellular events govern the functionality of siRNAs originating from transgenes in RNA interference/silencing pathways in C. albicans. PMID:20737430

  9. A FACS-Optimized Screen Identifies Regulators of Genome Stability in Candida albicans

    PubMed Central

    Loll-Krippleber, Raphaël; Feri, Adeline; Nguyen, Marie; Maufrais, Corinne; Yansouni, Jennifer; d'Enfert, Christophe

    2015-01-01

    Loss of heterozygosity (LOH) plays important roles in genome dynamics, notably, during tumorigenesis. In the fungal pathogen Candida albicans, LOH contributes to the acquisition of antifungal resistance. In order to investigate the mechanisms that regulate LOH in C. albicans, we have established a novel method combining an artificial heterozygous locus harboring the blue fluorescent protein and green fluorescent protein markers and flow cytometry to detect LOH events at the single-cell level. Using this fluorescence-based method, we have confirmed that elevated temperature, treatment with methyl methanesulfonate, and inactivation of the Mec1 DNA damage checkpoint kinase triggered an increase in the frequency of LOH. Taking advantage of this system, we have searched for C. albicans genes whose overexpression triggered an increase in LOH and identified four candidates, some of which are known regulators of genome dynamics with human homologues contributing to cancer progression. Hence, the approach presented here will allow the implementation of new screens to identify genes that are important for genome stability in C. albicans and more generally in eukaryotic cells. PMID:25595446

  10. Waikialoid A suppresses hyphal morphogenesis and inhibits biofilm development in pathogenic Candida albicans.

    PubMed

    Wang, Xiaoru; You, Jianlan; King, Jarrod B; Powell, Douglas R; Cichewicz, Robert H

    2012-04-27

    A chemically prolific strain of Aspergillus was isolated from a soil sample collected near Waikiki Beach, Honolulu, Hawaii. The fungus produced several secondary metabolites, which were purified and placed in our natural products library and were later screened for substances capable of inhibiting biofilm formation by Candida albicans. It was determined that one of the secondary metabolites from the Hawaiian fungal isolate, a new complex prenylated indole alkaloid named waikialoid A (1), inhibited biofilm formation with an IC(50) value of 1.4 μM. Another structurally unrelated, presumably polyketide metabolite, waikialide A (15), also inhibited C. albicans biofilm formation, but was much less potent (IC(50) value of 32.4 μM). Microscopy studies revealed that compound 1 also inhibited C. albicans hyphal morphogenesis. While metabolite 1 appears ineffective at disrupting preformed biofilms, the accumulated data indicate that the new compound may exert its activity against C. albicans during the early stages of surface colonization involving cell adherence, hyphal development, and/or biofilm assembly. Unlike some other stephacidin/notoamide compounds, metabolite 1 was not cytotoxic to fungi or human cells (up to 200 μM), which makes this an intriguing model compound for studying the adjunctive use of biofilm inhibitors in combination with standard antifungal antibiotics. PMID:22400916

  11. Antifungal activity, kinetics and molecular mechanism of action of garlic oil against Candida albicans.

    PubMed

    Li, Wen-Ru; Shi, Qing-Shan; Dai, Huan-Qin; Liang, Qing; Xie, Xiao-Bao; Huang, Xiao-Mo; Zhao, Guang-Ze; Zhang, Li-Xin

    2016-01-01

    The antifungal activity, kinetics, and molecular mechanism of action of garlic oil against Candida albicans were investigated in this study using multiple methods. Using the poisoned food technique, we determined that the minimum inhibitory concentration of garlic oil was 0.35 μg/mL. Observation by transmission electron microscopy indicated that garlic oil could penetrate the cellular membrane of C. albicans as well as the membranes of organelles such as the mitochondria, resulting in organelle destruction and ultimately cell death. RNA sequencing analysis showed that garlic oil induced differential expression of critical genes including those involved in oxidation-reduction processes, pathogenesis, and cellular response to drugs and starvation. Moreover, the differentially expressed genes were mainly clustered in 19 KEGG pathways, representing vital cellular processes such as oxidative phosphorylation, the spliceosome, the cell cycle, and protein processing in the endoplasmic reticulum. In addition, four upregulated proteins selected after two-dimensional fluorescence difference in gel electrophoresis (2D-DIGE) analysis were identified with high probability by mass spectrometry as putative cytoplasmic adenylate kinase, pyruvate decarboxylase, hexokinase, and heat shock proteins. This is suggestive of a C. albicans stress responses to garlic oil treatment. On the other hand, a large number of proteins were downregulated, leading to significant disruption of the normal metabolism and physical functions of C. albicans. PMID:26948845

  12. The Ess1 prolyl isomerase is required for growth and morphogenetic switching in Candida albicans.

    PubMed Central

    Devasahayam, Gina; Chaturvedi, Vishnu; Hanes, Steven D

    2002-01-01

    Prolyl-isomerases (PPIases) are found in all organisms and are important for the folding and activity of many proteins. Of the 13 PPIases in Saccharomyces cerevisiae only Ess1, a parvulin-class PPIase, is essential for growth. Ess1 is required to complete mitosis, and Ess1 and its mammalian homolog, Pin1, interact directly with RNA polymerase II. Here, we isolate the ESS1 gene from the pathogenic fungus Candida albicans and show that it is functionally homologous to the S. cerevisiae ESS1. We generate conditional-lethal (ts) alleles of C. albicans ESS1 and use these mutations to demonstrate that ESS1 is essential for growth in C. albicans. We also show that reducing the dosage or activity of ESS1 blocks morphogenetic switching from the yeast to the hyphal and pseudohyphal forms under certain conditions. Analysis of double mutants of ESS1 and TUP1 or CPH1, two genes known to be involved in morphogenetic switching, suggests that ESS1 functions in the same pathway as CPH1 and upstream of or in parallel to TUP1. Given that switching is important for virulence of C. albicans, inhibitors of Ess1 might be useful as antifungal agents. PMID:11805043

  13. Effect of ethanolic extract of Ecballium elaterium against Staphylococcus aureus and Candida albicans

    PubMed Central

    Adwan, Ghaleb; Salameh, Yousef; Adwan, Kamel

    2011-01-01

    Objective To evaluate the antimicrobial activity of ethanolic extract of Ecballium elaterium (E. elaterium) fruits alone against Staphylococcus aureus (S. aureus) strains and Candida albicans (C. albicans) strains, or in combination with penicillin against Staphylococcus areus strains. Methods Evaluation of the antimicrobial activity or synergy interaction was carried out using microdilution method. Results The results showed that ethanolic extract of E. elaterium fruits has antimicrobial activity against methicillin resistant S. aureus (MRSA), methicillin sensitive S. aureus (MSSA) and C. albicans. This extract showed a significant decrease in minimum inhibitory concentrations (MIC) of penicillin against both MRSA and MSSA strains. Fractional inhibitory concentration index (FIC) between penicillin and ethanolic extract of E. elaterium fruits against these test strains was less than 0.5. Conclusions This study suggests that ethanolic extract of E. elaterium fruits has antimicrobial activity against S. aureus and C. albicans and there is a possibility of concurrent use of penicillin and E. elaterium extract in combination in the treatment of infections caused by MRSA and MSSA strains. A wider study is needed to identify the effective components, the mode of action and the possible toxic effect in vivo of these ingredients. PMID:23569813

  14. Candida albicans Mucin Msb2 Is a Broad-Range Protectant against Antimicrobial Peptides

    PubMed Central

    Swidergall, Marc; Ernst, Andreas M.

    2013-01-01

    The human fungal pathogen Candida albicans releases a large glycofragment of the Msb2 surface protein (Msb2*) into the growth environment, which protects against the action of human antimicrobial peptides (AMPs) LL-37 and histatin-5. Quantitation of Msb2*/LL-37 interactions by microscale thermophoresis revealed high-affinity binding (dissociation constant [KD] = 73 nM), which was lost or greatly diminished by lack of O-glycosylation or by Msb2* denaturation. Msb2* also interacted with human α- and β-defensins and protected C. albicans against these AMPs. In addition, the lipopeptide antibiotic daptomycin was bound and inactivated by Msb2*, which prevented the killing of bacterial pathogens Staphylococcus aureus, Enterococcus faecalis, and Corynebacterium pseudodiphtheriticum. In coculturings or mixed biofilms of S. aureus with C. albicans wild-type but not msb2 mutant strains, the protective effects of Msb2* on the bactericidal action of daptomycin were demonstrated. These results suggest that tight binding of shed Msb2* to AMPs that occurs during bacterial coinfections with C. albicans compromises antibacterial therapy by inactivating a relevant reserve antibiotic. PMID:23733470

  15. The Antifungal Plant Defensin HsAFP1 from Heuchera sanguinea Induces Apoptosis in Candida albicans

    PubMed Central

    Aerts, An M.; Bammens, Leen; Govaert, Gilmer; Carmona-Gutierrez, Didac; Madeo, Frank; Cammue, Bruno P. A.; Thevissen, Karin

    2011-01-01

    Plant defensins are active against plant and human pathogenic fungi (such as Candida albicans) and baker's yeast. However, they are non-toxic to human cells, providing a possible source for treatment of fungal infections. In this study, we characterized the mode of action of the antifungal plant defensin HsAFP1 from coral bells by screening the Saccharomyces cerevisiae deletion mutant library for mutants with altered HsAFP1 sensitivity and verified the obtained genetic data by biochemical assays in S. cerevisiae and C. albicans. We identified 84 genes, which when deleted conferred at least fourfold hypersensitivity or resistance to HsAFP1. A considerable part of these genes were found to be implicated in mitochondrial functionality. In line, sodium azide, which blocks the respiratory electron transport chain, antagonized HsAFP1 antifungal activity, suggesting that a functional respiratory chain is indispensable for HsAFP1 antifungal action. Since mitochondria are the main source of cellular reactive oxygen species (ROS), we investigated the ROS-inducing nature of HsAFP1. We showed that HsAFP1 treatment of C. albicans resulted in ROS accumulation. As ROS accumulation is one of the phenotypic markers of apoptosis in yeast, we could further demonstrate that HsAFP1 induced apoptosis in C. albicans. These data provide novel mechanistic insights in the mode of action of a plant defensin. PMID:21993350

  16. Genome-Wide Synthetic Genetic Screening by Transposon Mutagenesis in Candida albicans

    PubMed Central

    Horton, Brooke N.; Kumar, Anuj

    2016-01-01

    Transposon-based mutagenesis is an effective method for genetic screening on a genome-wide scale, with particular applicability in organisms possessing compact genomes where transforming DNA tends to integrate by homologous recombination. Methods for transposon mutagenesis have been applied with great success in the budding yeast Saccharomyces cerevisiae and in the related pathogenic yeast Candida albicans. In C. albicans, we have implemented transposon mutagenesis to generate heterozygous mutations for the analysis of complex haploinsufficiency, a type of synthetic genetic interaction wherein a pair of non-complementing heterozygous mutations results in a stronger phenotype then either individual mutation in isolation. Genes exhibiting complex haploinsufficiency typically function within a regulatory pathway, in parallel pathways, or in parallel branches within a single pathway. Here, we present protocols to implement transposon mutagenesis for complex haploinsufficiency screening in C. albicans, indicating methods for transposon construction, mutagenesis, phenotypic screening, and identification of insertion sites in strains of interest. In total, the approach is a useful means to implement large-scale synthetic genetic screening in the diploid C. albicans. PMID:25636616

  17. Antifungal activity, kinetics and molecular mechanism of action of garlic oil against Candida albicans

    PubMed Central

    Li, Wen-Ru; Shi, Qing-Shan; Dai, Huan-Qin; Liang, Qing; Xie, Xiao-Bao; Huang, Xiao-Mo; Zhao, Guang-Ze; Zhang, Li-Xin

    2016-01-01

    The antifungal activity, kinetics, and molecular mechanism of action of garlic oil against Candida albicans were investigated in this study using multiple methods. Using the poisoned food technique, we determined that the minimum inhibitory concentration of garlic oil was 0.35 μg/mL. Observation by transmission electron microscopy indicated that garlic oil could penetrate the cellular membrane of C. albicans as well as the membranes of organelles such as the mitochondria, resulting in organelle destruction and ultimately cell death. RNA sequencing analysis showed that garlic oil induced differential expression of critical genes including those involved in oxidation-reduction processes, pathogenesis, and cellular response to drugs and starvation. Moreover, the differentially expressed genes were mainly clustered in 19 KEGG pathways, representing vital cellular processes such as oxidative phosphorylation, the spliceosome, the cell cycle, and protein processing in the endoplasmic reticulum. In addition, four upregulated proteins selected after two-dimensional fluorescence difference in gel electrophoresis (2D-DIGE) analysis were identified with high probability by mass spectrometry as putative cytoplasmic adenylate kinase, pyruvate decarboxylase, hexokinase, and heat shock proteins. This is suggestive of a C. albicans stress responses to garlic oil treatment. On the other hand, a large number of proteins were downregulated, leading to significant disruption of the normal metabolism and physical functions of C. albicans. PMID:26948845

  18. Antifungal activity and pore-forming mechanism of astacidin 1 against Candida albicans.

    PubMed

    Choi, Hyemin; Lee, Dong Gun

    2014-10-01

    In a previous report, a novel antibacterial peptide astacidin 1 (FKVQNQHGQVVKIFHH) was isolated from hemocyanin of the freshwater crayfish Pacifastacus leniusculus. In this study, the antifungal activity and mechanism of astacidin 1 were evaluated. Astacidin 1 exhibited antifungal activity against Candida albicans, Trichosporon beigelii, Malassezia furfur, and Trichophyton rubrum. Also, astacidin 1 had fungal cell selectivity in human erythrocytes without causing hemolysis. To understand the antifungal mechanism, membrane studies were done against C. albicans and T. beigelii. Flow cytometric analysis and K(+) measurement showed membrane damage, resulting in membrane permeabilization and K(+) release-induced membrane depolarization. Furthermore, the calcein leakage from liposomes mimicking C. albicans membrane demonstrated that the membrane-active action was driven by pore-forming mechanism. Live cell imaging using fluorescein isothiocyanate-labeled dextrans of various sizes suggested that the radii of pores formed in the C. albicans membrane were 1.4-2.3 nm. Therefore, the present study suggests that astacidin 1 exerts its antifungal effect by damaging the fungal membrane via pore formation. PMID:24955933

  19. Proteomics unravels extracellular vesicles as carriers of classical cytoplasmic proteins in Candida albicans.

    PubMed

    Gil-Bona, Ana; Llama-Palacios, Arancha; Parra, Claudia Marcela; Vivanco, Fernando; Nombela, César; Monteoliva, Lucía; Gil, Concha

    2015-01-01

    The commensal fungus Candida albicans secretes a considerable number of proteins and, as in different fungal pathogens, extracellular vesicles (EVs) have also been observed. Our report contains the first proteomic analysis of EVs in C. albicans and a comparative proteomic study of the soluble secreted proteins. With this purpose, cell-free culture supernatants from C. albicans were separated into EVs and EV-free supernatant and analyzed by LC-MS/MS. A total of 96 proteins were identified including 75 and 61 proteins in EVs and EV-free supernatant, respectively. Out of these, 40 proteins were found in secretome by proteomic analysis for the first time. The soluble proteins were enriched in cell wall and secreted pathogenesis related proteins. Interestingly, more than 90% of these EV-free supernatant proteins were classical secretory proteins with predicted N-terminal signal peptide, whereas all the leaderless proteins involved in metabolism, including some moonlighting proteins, or in the exocytosis and endocytosis process were exclusively cargo of the EVs. We propose a model of the different mechanisms used by C. albicans secreted proteins to reach the extracellular medium. Furthermore, we tested the potential of the Bgl2 protein, identified in vesicles and EV-free supernatant, to protect against a systemic candidiasis in a murine model. PMID:25367658

  20. Humoral immune responses to Candida albicans complement receptor 3-related protein in the atopic subjects with vulvovaginal candidiasis. Novel sensitive marker for Candida infection.

    PubMed

    Paulovičová, Ema; Bujdáková, Helena; Chupáčová, Jarmila; Paulovičová, Lucia; Kertys, Pavol; Hrubiško, Martin

    2015-03-01

    In vitro evaluation of specific anti-Candida albicans sera antibodies based on synthetically prepared complement receptor 3-related protein (CR3-RP) mimicking the structure of native complement receptor 3 in a cohort of 72 patients with atopy and recurrent Candida vulvovaginitis (RVC) revealed effective humoral response against Candida CR3-RP. The most significant have been IgM and IgA isotype antibodies (33 and 47% positive cases, respectively). The quantitative evaluation of anti-CR3RP isotype antibodies was confronted with results of commercial ELISA anti-C. albicans antibodies diagnostics based on C. albicans cell wall mannan and β-glucan antigens, the most significant correlation being observed with anti-CR3-RP IgM and anti-β-D-glucan IgM (r(2) = 0.624) followed by isotype IgA (r(2) = 0.381). The immunogenicity and immunoreactivity of CR3RP antigen in RVC patients' sera had been evaluated with regard to the results reached by counterimmunoelectrophoresis and heterogeneous enzyme immunoassay. Obviously, synthetically prepared CR3-RP mimicking the Candida cell-wall-derived structure moiety represents a promising immunological tool not only for Candida serodiagnostics, but also prospectively for follow-up of targeted antifungal therapy and as promising Candida vaccine candidate. PMID:25673750

  1. Effect of alcohols on filamentation, growth, viability and biofilm development in Candida albicans.

    PubMed

    Chauhan, Nitin M; Shinde, Ravikumar B; Karuppayil, S Mohan

    2013-12-01

    In this study we report the potential of alcohols as morphogenetic regulators in Candida albicans. All the alcohols tested influenced various modes of growth like planktonic as well as biofilm forms. Viability was affected at high concentrations. Among the alcohols, the response of C. albicans to amyl alcohol (pentanol) was noteworthy. Amyl alcohol at a concentration 0.5% which was not inhibitory to growth and viability specifically inhibited morphogenetic switching from yeast to hyphal forms. It also inhibited normal biofilm development favoring yeast dominated biofilms. Based on this study we hypothesize that alcohols produced under anaerobic conditions may not favor biofilm development and support dissemination of yeast cells. Since anaerobic conditions are not found to favor production of quorum sensing molecules like farnesol, the alcohols may play a role in morphogenetic regulation. PMID:24688528

  2. Chemosensitization of multidrug resistant Candida albicans by the oxathiolone fused chalcone derivatives

    PubMed Central

    Ła̧cka, Izabela; Konieczny, Marek T.; Bułakowska, Anita; Kodedová, Marie; Gašková, Dana; Maurya, Indresh K.; Prasad, Rajendra; Milewski, Sławomir

    2015-01-01

    Three structurally related oxathiolone fused chalcone derivatives appeared effective chemosensitizers, able to restore in part sensitivity to fluconazole of multidrug-resistant C. albicans strains. Compound 21 effectively chemosensitized cells resistant due to the overexpression of the MDR1 gene, compound 6 reduced resistance of cells overexpressing the ABC-type drug transporters CDR1/CDR2 and derivative 18 partially reversed fluconazole resistance mediated by both types of yeast drug efflux pumps. The observed effect of sensitization of resistant strains of Candida albicans to fluconazole activity in the presence of active compounds most likely resulted from inhibition of the pump-mediated efflux, as was revealed by the results of studies involving the fluorescent probes, Nile Red, Rhodamine 6G and diS-C3(3). PMID:26300857

  3. Thiamin Pyrimidine Biosynthesis in Candida albicans: A Remarkable Reaction between Histidine and Pyridoxal Phosphate

    SciTech Connect

    Lai, Rung-Yi; Huang, Siyu; Fenwick, Michael K.; Hazra, Amrita; Zhang, Yang; Rajashankar, Kanagalaghatta; Philmus, Benjamin; Kinsland, Cynthia; Sanders, Jennie Mansell; Ealick, Steven E.; Begley, Tadhg P.

    2012-06-26

    In Saccharomyces cerevisiae, thiamin pyrimidine is formed from histidine and pyridoxal phosphate (PLP). The origin of all of the pyrimidine atoms has been previously determined using labeling studies and suggests that the pyrimidine is formed using remarkable chemistry that is without chemical or biochemical precedent. Here we report the overexpression of the closely related Candida albicans pyrimidine synthase (THI5p) and the reconstitution and preliminary characterization of the enzymatic activity. A structure of the C. albicans THI5p shows PLP bound at the active site via an imine with Lys62 and His66 in close proximity to the PLP. Our data suggest that His66 of the THI5 protein is the histidine source for pyrimidine formation and that the pyrimidine synthase is a single-turnover enzyme.

  4. Synergistic action of starch and honey against Candida albicans in correlation with diastase number

    PubMed Central

    Boukraa, Laïd; Benbarek, Hama; Moussa, Ahmed

    2008-01-01

    To evaluate the synergistic action of starch on the antifungal activity of honey, a comparative method of adding honey with and without starch to culture media was used. Candida albicans has been used to determine the minimum inhibitory concentration (MIC) of five varieties of honey. In a second step, lower concentrations of honey than the MIC were incubated with a set of concentrations of starch added to media to determine the minimum synergistic inhibitory concentration (MSIC). The MIC for the five varieties of honey without starch against C. albicans ranged between 40% and 45% (v/v). When starch was incubated with honey and then added to media, a MIC drop has been noticed with each variety. It ranged between 7% and 25%. A negative correlation has been established between the MIC drop and the diastase number (DN). PMID:24031175

  5. Quick Detection of FKS1 Mutations Responsible for Clinical Echinocandin Resistance in Candida albicans.

    PubMed

    Dudiuk, Catiana; Gamarra, Soledad; Jimenez-Ortigosa, Cristina; Leonardelli, Florencia; Macedo, Daiana; Perlin, David S; Garcia-Effron, Guillermo

    2015-07-01

    A rapid molecular-based assay for the detection of the Candida albicans FKS1 gene mutations responsible for resistance to echinocandin drugs was designed and evaluated. The assay consisted of a multiplexed PCR set of 5 tubes able to detect the most commonly described resistance mechanism, including FKS1 hot spot 1 and hot spot 2 mutations. The performance and specificity of the assay was evaluated using a double-blinded panel of 50 C. albicans strains. The assay showed a sensitivity of 96% and was able to detect all homozygous mutants included in the collection of strains, demonstrating that it is a robust, quick, and labor-saving method that is suitable for a routine clinical diagnostic laboratory. PMID:25878347

  6. Allyl alcohol and garlic (Allium sativum) extract produce oxidative stress in Candida albicans

    PubMed Central

    Lemar, Katey M.; Passa, Ourania; Aon, Miguel A.; Cortassa, Sonia; Müller, Carsten T.; Plummer, Sue; O’Rourke, Brian; Lloyd, David

    2009-01-01

    Both the growth and respiration of Candida albicans are sensitive to extracts of Allium sativum and investigations into the anticandidal activities are now focussing on the purified constituents to determine the targets of inhibition. Of particular interest is allyl alcohol (AA), a metabolic product that accumulates after trituration of garlic cloves. Putative targets for AA were investigated by monitoring changes in intracellular responses after exposure of C. albicans cells to AA or a commercially available garlic extract. Two-photon laser scanning microscopy and other techniques were used. Changes typical of oxidative stress – NADH oxidation and glutathione depletion, and increased reactive oxygen species – were observed microscopically and by flow cytometry. Known targets for AA are alcohol dehydrogenases Adh1 and 2 (in the cytosol) and Adh3 (mitochondrial), although the significant decrease in NAD(P)H after addition of AA is indicative of another mechanism of action. PMID:16207909

  7. Effect of alcohols on filamentation, growth, viability and biofilm development in Candida albicans

    PubMed Central

    Chauhan, Nitin M; Shinde, Ravikumar B; Karuppayil, S. Mohan

    2013-01-01

    In this study we report the potential of alcohols as morphogenetic regulators in Candida albicans. All the alcohols tested influenced various modes of growth like planktonic as well as biofilm forms. Viability was affected at high concentrations. Among the alcohols, the response of C. albicans to amyl alcohol (pentanol) was noteworthy. Amyl alcohol at a concentration 0.5% which was not inhibitory to growth and viability specifically inhibited morphogenetic switching from yeast to hyphal forms. It also inhibited normal biofilm development favoring yeast dominated biofilms. Based on this study we hypothesize that alcohols produced under anaerobic conditions may not favor biofilm development and support dissemination of yeast cells. Since anaerobic conditions are not found to favor production of quorum sensing molecules like farnesol, the alcohols may play a role in morphogenetic regulation. PMID:24688528

  8. 5-fluoro-orotic acid induces chromosome alterations in genetically manipulated strains of Candida albicans.

    PubMed

    Wellington, Melanie; Kabir, M Anaul; Rustchenko, Elena

    2006-01-01

    We previously reported the occurrence of chromosome alterations in a Candida albicans prototrophic strain 3153A treated with 5-fluoro-orotic acid (5-FOA). In this study we investigated the mutagenic properties of 5-FOA with two derivatives of C. albicans strain CAF4-2 (ura3/ura3), each containing an ectopic copy of URA3 gene (ura3/ ura3 URA3) on a different chromosome. As expected, after the ura3/ura3 URA3 constructs were applied to 5-FOA containing solid medium, the "pop-outs" that lost URA3 appeared. However most of the "pop-outs" acquired various chromosome alterations. Thus constructs exposed to 5-FOA should be examined for chromosome alterations or the use of 5-FOA should be avoided. PMID:17040068

  9. 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. PMID:26920878

  10. Candida albicans osteomyelitis as a cause of chest pain and visual loss.

    PubMed

    Magano, Rita; Cortez, Joana; Ramos, Evelise; Trindade, Luís

    2015-01-01

    Candida albicans osteomyelitis is a rare disease that occurs in immunocompromised individuals, sometimes with a late diagnosis related to the mismatch between symptoms and candidemia. This case refers to a 36-year-old male patient with a history of oesophageal surgery for achalasia with multiple subsequent surgeries and hospitalisation in the intensive care unit for oesophageal fistula complication. Four months after discharge, the patient was admitted to the infectious diseases department with pain in the 10th-12th left ribs, swelling of the 4th-6th costal cartilage and decreased visual acuity. An MRI study showed thickening and diffuse enhancement, with no defined borders in the cartilage and ribs, compatible with infection. After performing a CT-guided bone biopsy, isolated C. albicans sensitive to antifungal agents was detected. The patient started therapy with liposomal amphotericin B and maintenance fluconazole for 6 months and showed clinical and radiological improvement within this time. PMID:26475877

  11. High frame-rate resolution of cell division during Candida albicans filamentation.

    PubMed

    Thomson, Darren D; Berman, Judith; Brand, Alexandra C

    2016-03-01

    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

  12. Neonatal malnutrition programs the oxidant function of macrophages in response to Candida albicans.

    PubMed

    Costa, Thacianna Barreto Da; Morais, Natália Gomes De; Pedrosa, Amanda Lúcia F; De Albuquerque, Suênia Da Cunha G; De Castro, Maria Carolina A B; Pereira, Valéria Rêgo A; Cavalcanti, Milena De Paiva; De Castro, Célia Maria M B

    2016-06-01

    Experimental maternal nutrition restriction models are used to investigate short or long-term consequences of nutritional deficiency on puppies' growth. By assuming that the immune function is directly related to host's nutritional status, the current study aims to investigate the effects of neonatal malnutrition on oxidative stress and on the cell death of the alveolar macrophage after in vitro infection by Candida albicans. Wistar rats were suckled by mothers fed on diets containing 17% protein (Nourished group) or 8% protein (Malnourished group) in the current assay. Both groups received the standard diet used in the vivarium until adulthood, after weaning. The results showed that the offspring from mothers fed on low-protein diet presented lower body weight from 5 days of life on. Their low weight remained until adulthood when it was compared to that of rats in the nourished group. Superoxide and nitric oxide production was lower in malnourished animals and it was accompanied by low inducible nitric oxide synthase gene expression levels in systems in which the alveolar macrophages were challenged by immunogenic stimulus. No significant differences were observed in comparisons performed between the nourished and malnourished groups in any of the analyzed cell viability (apoptosis/necrosis) parameters. The fungal inoculum-stimulated system induced higher oxidative stress and cell death by necrosis. The current study demonstrated that dietary restriction during lactation alters the oxidant function of alveolar macrophages in puppies; It happens from the gene transcription step to the release of mediators, thus compromising the host's defenses against Candida albicans. It raises the possibility that Candida albicans may cease to be a commensal fungus to become a pathogen in offspring that have suffered nutritional deficiency during critical developmental periods, due to impaired immune responses. PMID:27001703

  13. Epidemiology of Candida infection. II. Application of biochemical methods for typing of Candida albicans strains.

    PubMed

    Budak, A

    1990-01-01

    Biochemical profiles of 350 C. albicans isolates from five towns in Poland and from Freiburg in Germany were determined on the basis of nine biochemical tests of Odds and Abbott method. API 20 C AUX system and additionally a resistogram. The analysis of the strains according to Odds' and Abbotts's system showed that investigated strains can be typed into 9 profile codes of common biochemical patterns. There were some differences among the profiles according to their geographical origin and anatomical sources of the isolation. On the basis of the ability C. albicans strains to assimilate of carbon sources, 350 isolates were categorised into 13 separate auxotrophic profiles with the major one: 2,576,174 accounting for 81% of the total. The majority of the investigated isolates were susceptible to antifungal agents (83%). A disproportionate distribution of auxotrophic profiles limited the use of resistogram method and API 20 C AUX as systems for typing C. albicans strains. On the other hand, the method of Odds and Abbott provides valuable criteria for typing of C. albicans. PMID:2130802

  14. Ultrastructural and biochemical studies of two dynamically expressed cell surface determinants on Candida albicans.

    PubMed Central

    Brawner, D L; Cutler, J E

    1986-01-01

    Variability in the expression of two different cell surface carbohydrate determinants was examined with two agglutinating immunoglobulin M monoclonal antibodies (H9 and C6) and immunoelectron microscopy during growth of three strains of Candida albicans. A single strain of Candida parapsilosis did not express either antigen at any time during growth. Antigens were detected on the surface of C. albicans by agglutination tests with either H9 or C6 over a 48-h growth period. The difference in specificities of the monoclonal antibodies was demonstrated by Ouchterlony double-diffusion tests with solubilized antigens and by variabilities in the reactivity of the agglutinins among yeast strains. The antigenic determinants were isolated by specific immunoprecipitation and protease digestion and characterized by methods including high-pressure liquid chromatography, gas-liquid chromatography, and mass spectroscopy with both chemical and electron ionization. These determinants both contain mannose and glucose. In the case of antigen H9, an additional carbohydrate was detected with gas chromatography and mass spectroscopy. The location of antigens on individual cells was determined by indirect labeling of the determinants, first reacting cells with H9 or C6 followed by goat anti-mouse antibody conjugated with 20-nm colloidal gold particles. Transmission electron microscopy was used to examine cells. The antigens that were reactive with the monoclonal antibodies were associated with a flocculent surface layer. Expression of this layer and expression of the antigens is a dynamic process which is growth phase and strain dependent. The antigens were not expressed on very young cells and disappeared from the cell surface of most C. albicans strains with age. The use of monoclonal antibody to cell surface determinants may allow characterization of cell surface antigens of C. albicans and be helpful in establishing receptors which mediate adherence. Images PMID:3510174

  15. Secretory Aspartyl Proteinases Cause Vaginitis and Can Mediate Vaginitis Caused by Candida albicans in Mice

    PubMed Central

    Pericolini, Eva; Gabrielli, Elena; Amacker, Mario; Kasper, Lydia; Roselletti, Elena; Luciano, Eugenio; Sabbatini, Samuele; Kaeser, Matthias; Moser, Christian; Hube, Bernhard; Vecchiarelli, Anna

    2015-01-01

    ABSTRACT Vaginal inflammation (vaginitis) is the most common disease caused by the human-pathogenic fungus Candida albicans. Secretory aspartyl proteinases (Sap) are major virulence traits of C. albicans that have been suggested to play a role in vaginitis. To dissect the mechanisms by which Sap play this role, Sap2, a dominantly expressed member of the Sap family and a putative constituent of an anti-Candida vaccine, was used. Injection of full-length Sap2 into the mouse vagina caused local neutrophil influx and accumulation of the inflammasome-dependent interleukin-1β (IL-1β) but not of inflammasome-independent tumor necrosis factor alpha. Sap2 could be replaced by other Sap, while no inflammation was induced by the vaccine antigen, the N-terminal-truncated, enzymatically inactive tSap2. Anti-Sap2 antibodies, in particular Fab from a human combinatorial antibody library, inhibited or abolished the inflammatory response, provided the antibodies were able, like the Sap inhibitor Pepstatin A, to inhibit Sap enzyme activity. The same antibodies and Pepstatin A also inhibited neutrophil influx and cytokine production stimulated by C. albicans intravaginal injection, and a mutant strain lacking SAP1, SAP2, and SAP3 was unable to cause vaginal inflammation. Sap2 induced expression of activated caspase-1 in murine and human vaginal epithelial cells. Caspase-1 inhibition downregulated IL-1β and IL-18 production by vaginal epithelial cells, and blockade of the IL-1β receptor strongly reduced neutrophil influx. Overall, the data suggest that some Sap, particularly Sap2, are proinflammatory proteins in vivo and can mediate the inflammasome-dependent, acute inflammatory response of vaginal epithelial cells to C. albicans. These findings support the notion that vaccine-induced or passively administered anti-Sap antibodies could contribute to control vaginitis. PMID:26037125

  16. Candida albicans VPS4 contributes differentially to epithelial and mucosal pathogenesis

    PubMed Central

    Rane, Hallie S; Hardison, Sarah; Botelho, Claudia; Bernardo, Stella M; Wormley, Floyd; Lee, Samuel A

    2014-01-01

    We have previously demonstrated that the C. albicans pre-vacuolar protein sorting gene VPS4 is required for extracellular secretion of the secreted aspartyl proteases Sap2p and Saps4–6p. Furthermore, the vps4Δ null mutant has been shown to be markedly hypovirulent in a murine tail vein model of disseminated candidiasis. In these experiments, we sought to further define the role of the pre-vacuolar secretion pathway mediated by the pre-vacuolar sorting gene VPS4 in the pathogenesis of epithelial and mucosal infection using a broad range of virulence models. The C. albicans vps4Δ mutant demonstrates reduced tolerance of cell wall stresses compared to its isogenic, complemented control strain. In an in vitro oral epithelial model (OEM) of tissue invasion, the vps4Δ mutant caused reduced tissue damage compared to controls. Further, the vps4Δ mutant was defective in macrophage killing in vitro, and was attenuated in virulence in an in vivo Caenorhabditis elegans model representative of intestinal epithelial infection. In contrast, the vps4Δ mutant caused a similar degree of tissue damage in an in vitro uroepithelial model of Candida infection compared with controls. Furthermore, in an in vivo murine model of vaginal candidiasis there was no reduction in fungal colony burden and no differences in vaginal histopathology compared to wild-type and complemented controls. These results suggest that VPS4 contributes to several key aspects of oral epithelial but not uroepithelial infection, and in contrast to systemic infection, plays no major role in the pathogenesis of Candida vaginitis. By using a wide range of virulence models, we demonstrate that C. albicans VPS4 contributes to virulence according to the specific tissue that is infected. Thus, in order to gain a full understanding of C. albicans virulence in relation to a particular gene or pathway of interest, a selected range of infection models may need to be utilized. PMID:25483774

  17. Modification of Surface Properties of Biomaterials Influences the Ability of Candida albicans To Form Biofilms

    PubMed Central

    Chandra, Jyotsna; Patel, Jasmine D.; Li, Jian; Zhou, Guangyin; Mukherjee, Pranab K.; McCormick, Thomas S.; Anderson, James M.; Ghannoum, Mahmoud A.

    2005-01-01

    Candida albicans biofilms form on indwelling medical devices (e.g., denture acrylic or intravenous catheters) and are associated with both oral and invasive candidiasis. Here, we determined whether surface modifications of polyetherurethane (Elasthane 80A [E80A]), polycarbonateurethane, and poly(ethyleneterephthalate) (PET) can influence fungal biofilm formation. Polyurethanes were modified by adding 6% polyethylene oxide (6PEO), 6% fluorocarbon, or silicone, while the PET surface was modified to generate hydrophilic, hydrophobic, cationic, or anionic surfaces. Formation of biofilm was quantified by determining metabolic activity and total biomass (dry weight), while its architecture was analyzed by confocal scanning laser microscopy (CSLM). The metabolic activity of biofilm formed by C. albicans on 6PEO-E80A was significantly reduced (by 78%) compared to that of biofilm formed on the nonmodified E80A (optical densities of 0.054 ± 0.020 and 0.24 ± 0.10, respectively; P = 0.037). The total biomass of Candida biofilm formed on 6PEO-E80A was 74% lower than that on the nonmodified E80A surface (0.46 ± 0.15 versus 1.76 ± 0.32 mg, respectively; P = 0.003). Fungal cells were easily detached from the 6PEO-E80A surface, and we were unable to detect C. albicans biofilm on this surf