agar and Candidiasis--Vulvovaginal

Vulvovaginal candidiasis/candidosis is a common fungal infection afflicting approximately 75% of women globally caused primarily by the yeast Candida albicans. Fluconazole is widely regarded as the antifungal drug of choice since its introduction in 1990 due to its high oral bioavailability, convenient dosing regimen and favourable safety profile. However, its widespread use has led to the emergence of fluconazole-resistant C. albicans, posing a universal clinical concern. Coupled to the dearth of new antifungal drugs entering the market, it is imperative to introduce new drug classes to counter this threat. Antimicrobial peptides (AMPs) are potential candidates due to their membrane-disrupting mechanism of action. By specifically targeting fungal membranes and being rapidly fungicidal, they can reduce the chances of resistance development and treatment duration. Towards this goal, we conducted a head-to-head comparison of 61 short linear AMPs from the literature to identify the peptide with the most potent activity against fluconazole-resistant C. albicans. The 11-residue peptide, P11-6, was identified and assayed against a panel of clinical C. albicans isolates followed by fungicidal/static determination and a time-kill assay to gauge its potential for further drug development. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

Topics: Agar; Amino Acid Sequence; Antifungal Agents; Antimicrobial Cationic Peptides; Candida albicans; Candidiasis, Vulvovaginal; Drug Resistance, Fungal; Female; Fluconazole; Humans; Miconazole; Microbial Sensitivity Tests; Quantitative Structure-Activity Relationship

Vulvovaginal candidiasis (VVC), particularly the recurrent form, remains an intractable problem for clinicians, microbiologists, and patients. It is essential to confirm the clinical diagnosis by mycological methods and avoid empirical therapy. The recovery of yeast in fungal culture, such as on Sabouraud dextrose agar, remains the gold standard for diagnosis. In this investigation, we examined 474 participants, including 122 (25.7%) with acute VVC cases, 249 (52.5%) who had recurrent VVC (RVVC) cases, and 103 (21.7%) healthy controls. We also administered a questionnaire to obtain information on patient lifestyle and medical, gynecological, and sexual history. In addition, we compared the performance of chromID Candida agar (CAN2) to CHROMagar Candida (CAC) and Sabouraud dextrose agar with gentamicin and chloramphenicol (SGC2). The yeasts were identified by conventional methods including the germ tube test, microscopic morphology on cornmeal-Tween 80 agar, and the commercial API 20C AUX system. We detected yeasts in 60 of 122 (49.2%) patients with acute VVC cases, 110 of 249 (44.2%) with RVVC cases, and in 35 of 103 (34%) healthy controls (P = 0.07). A total of 205 samples were found to be positive for fungi (43.2%), of which 176 (85.9%) were monofungal, and 29 (14.1%) were polyfungal. In addition, 198 of these samples (96.6%) were positive on CAN2, 195 (95.1%) on CAC, 189 (92.2%) on SGC2, and 183 (89.3%) samples on all three (P = 0.17). The 234 yeast isolates recovered were C. albicans (n = 118), C. glabrata (n = 82), C. kefyr (n = 11), C. krusei (n = 9), C. lipolytica (n = 3), C. colliculosa (n = 2), C. parapsilosis (n = 2), C. pelliculosa (n = 2), C. tropicalis (n = 2), and other species of Candida (n = 3). Of the 29 polyfungal populations, 28 (96.6%) were detected in CAN2, 25 in (86.2%) CAC, and 25 (86.2%) on both (P = 0.35). Notably, we detected the high predominance of C. albicans+C. glabrata (86.2%) in polyfungal populations. Briefly, the detection of C. albicans after 24 h of incubation was easier on CAN2 (64.4%) than on CAC (25.4%). This study showed that CAN2 is a rapid and reliable medium for immediate identification of C. albicans and for detecting polyfungal populations in vaginal specimens. We observed that the use of antibiotics, intrauterine devices, as well as, perineal laceration, short anovaginal distance (< 3 cm), and genital epilation in common areas are predisposing factors for RVVC (P < 0.001). In addition, we detected that the use

Topics: Adolescent; Adult; Agar; Candida; Candidiasis, Vulvovaginal; Culture Media; Female; Humans; Middle Aged; Mycology; Recurrence; Risk Factors; Surveys and Questionnaires; Young Adult

Chromogenic Candida agar (OCCA) is a novel medium facilitating isolation and identification of Candida albicans, C. tropicalis, and C. krusei, as well as indicating polyfungal population in clinical samples. We compare the performance of OCCA, to CHROMagar Candida (CAC) and Sabouraud chloramphenicol agar (SCA). Vaginal swab samples from 392 women were simultaneously inoculated onto three study media. A total of 161 (41.1%) were found to be positive for fungi of which 140 (87%) were monofungal, and 21 (13%) polyfungal. One-hundred and fifty-seven samples (97.5%) were positive on CAC, 156 (96.9%) on OCCA, 148 (91.9%) on SCA and 144 (89.4%) samples were positive on all three media. The yeasts were identified by conventional methods including germ tube test, microscopic morphology on cornmeal-Tween 80 agar, and the commercial API 20C AUX. The 182 isolates were C. albicans (n = 104), C. glabrata (n = 51), C. krusei (n = 7), C. tropicalis (n = 5), C. famata (n = 3), C. kefyr (n = 3), C. zeylanoides (n = 3), C. colliculosa (n = 2), and other species of Candida (n = 4). Among the 21 polyfungal populations, 20 (95.2%) were detected in OCCA, 14 (66.7%) in CAC, and 13 (61.9%) in CAC and OCCA (P <0.05). Most polyfungal populations (47.6%) yielded C. albicans + C. glabrata. The efficiency of both chromogenic media for C. albicans was >or=92.9% at 72 h. OCCA is more efficient and reliable for rapidly identifying C. albicans and polyfungal populations than CAC. However, CAC is more efficient for identifying C. krusei and C. tropicalis. A chromogenic agar with a higher isolation rate of yeasts and better detection of polyfungal populations than SCA, is suggested as a medium of first choice when available.

Topics: Agar; Candida; Candidiasis, Vulvovaginal; Culture Media; Female; Humans; Mycology; Sensitivity and Specificity; Vagina

Even though vulvovaginal candidiasis and bacterial vaginosis are seldom simultaneously found, we have detected this association at an above average frequency. Thus, we set out to study the activity of proteinases and phospholipases, virulence factors of Candida albicans, to assess their role in the above mentioned association. Of a total of 70 Candida isolates were retrieved from samples of vaginal secretions analyzed at our Diagnostic Service, 65 were identified as C. albicans (a group of n=26 obtained from clinical samples of pH>4.5 and a group of n=39 from clinical samples of pH=or<4.5). The evaluation of phospholipases activity was performed on malt agar and Sabouraud dextrose agar with the addition of egg yolk as substrate. The proteolytic activity was detected on plates of agar base medium with the addition of bovine albumin serum as substrate as sole nitrogen source. Phospholipases activity was essentially the same in both groups of samples (p=0.2003). Proteolytic activity was detected in 61.5% of the isolates from the group with pH=or<4.5 and in 96.2% in the group with pH>4.5; being the former much higher than the latter (p=0.0001). Based on these results we postulate that the simultaneous occurrence of bacterial vaginosis and vulvovaginal candidiasis could be related to the proteolytic activity but unrelated to phospholipases activity.

Topics: Adult; Agar; Body Fluids; Candida albicans; Candidiasis, Vulvovaginal; Culture Media; Edible Grain; Egg Yolk; Female; Fungal Proteins; Gardnerella vaginalis; Humans; Hydrogen-Ion Concentration; Peptide Hydrolases; Phospholipases; Vagina; Vaginosis, Bacterial; Virulence

Candida dubliniensis is very similar to Candida albicans in terms of genotypic and phenotypic characteristics. As the hormonal milieu of the vagina during pregnancy, characterised by a lack of maternal cell-mediated immunity, enhances Candida colonisation and serves as a risk factor for symptomatic expression, investigation into the isolation of C. dubliniensis in vaginal discharges of pregnant women with vulvovaginal candidosis was made. A total of 77 Candida isolates obtained from 60 patients positive for vulvovaginal candidosis collected from 218 pregnant women were investigated for C. dubliniensis subsistence. In total 41 Candida species phenotypically identified as C. albicans on the basis of a positive germ tube test and carbohydrate assimilation tests were screened for the presence of C. dubliniensis. Phenotypic tests for differentiation of C. dubliniensis from C. albicans, such as growth at 42 and 45 degrees C on Sabouraud dextrose agar, appearance on CHROMagar and colony morphology on Cornmeal-Tween-80 agar and Staib agar were carried out. Only one strain (2.43%) was phenotypically identified as C. dubliniensis. According to our study, a combination of at least five phenotypic methods is necessary for an exact diagnosis of C. dubliniensis. Large-scale studies of pregnant women are required to discover the aetiological importance of this yeast.

Topics: Agar; Candida; Candidiasis, Vulvovaginal; Culture Media; Female; Hospitals, University; Humans; Mycological Typing Techniques; Phenotype; Pregnancy; Pregnancy Complications, Infectious; Prevalence; Spores, Fungal; Turkey

In this study, 250 vaginal samples from patients with vulvovaginal candidosis were inoculated onto two chromogenic media, Albicans ID(2) and Biggy agar, as well as onto Sabouraud chloramphenicol agar, yielding a total of 63 yeast (25.2 %) on all three media. These strains were identified as Candida glabrata in 20 (31.8 %) samples, Candida albicans in 15 samples (23.8 %), Candida tropicalis in 10 samples (15.9 %), Candida krusei in five samples (7.9 %), Candida kefyr in five samples (7.9 %), Candida dubliniensis in four samples (6.3 %), Candida parapsilosis in two samples (3.2 %) and Candida guilliermondii in two samples (3.2 %). Mixed fungal cultures and bacterial growth or filamentous fungi were not detected on any of the selected media. The sensitivity and specificity of the Albicans ID(2) and Biggy agar with regard to the identification of C. albicans were 80.0 and 64.6 %, and 86.7 and 56.3 %, respectively. This study showed these two chromogenic media to be as effective as Sabouraud chloramphenicol agar with respect to fungal detection. However, neither Albicans ID(2) nor Biggy agar was sufficient for reliable differentiation of yeasts to the species level.

Topics: Agar; Bacteria; Candida; Candidiasis, Vulvovaginal; Color; Culture Media; Female; Humans; Mycology; Sensitivity and Specificity; Vagina

The objectives were to compare the outcome of polymerase chain reaction (PCR), culture and microscopy of introital and vaginal samples for detection of candida in women with a history of recurrent vulvovaginal candidosis (RVVC). One hundred and three women with a history of RVVC, i.e. with at least four episodes of the condition in the previous year and who consulted with complaints consistent with a new episode, were studied. Introital and vaginal swabs were cultured on Sabouraud and CHROMagar. Isolated strains were identified on the chromogenic agar and by API 32C kits and by Vitek automatized identification system (BioMérieux, France). PCR for detection of Candida spp. was performed on vaginal lavage fluid. There was a complete agreement in the recovery rate when using the two agar media. However, complete concordance was not obtained between culture and PCR. In 32 (43.8%) of 73 women both PCR and culture were positive, and in 17 (23.3%) both were negative. In 15 (20.5%), only cultures proved positive, while in another 13 (17.8%) patients only the PCR was positive. Four of the PCR-negative became PCR-positive on retesting after dilution of the sample to try to reduce any potential putative PCR inhibitors. In the 47 PCR-positive women, 26 (55.3%) of the introital smears and 31 (65.9%) posterior vaginal smears showed candida morphotypes. In the 25 PCR-negative women, the corresponding figures were 9 (36.0%) and 17 (68.0%), respectively. The PCR test identified Candida albicans in 21 (87.5%) instances, but failed to do so in three (12.5%) cases in which the metabolic/assimilation tests were positive for this species. The corresponding figures for non-albicans Candida spp. were four (57%) and three (43%), respectively. The study of women with RVVC did not show any uniform agreement between the different diagnostic methods used to identify candida in genital samples or for speciation of yeast isolates. Thus reliance only on microscopy, culture or PCR may lead to inaccurate results.

Topics: Adolescent; Adult; Agar; Candida; Candidiasis, Vulvovaginal; Culture Media; Female; Humans; Microscopy; Polymerase Chain Reaction; Recurrence; Vagina; Vaginal Smears

Candida glabrata switches spontaneously at high frequency among the following four graded phenotypes discriminated on agar containing 1 mM CuSO(4): white, light brown, dark brown (DB), and very dark brown. C. glabrata also contains three mating type loci with a configuration similar to that of the Saccharomyces cerevisiae mating type cassette system, suggesting it may also undergo cassette switching at the expression locus MTL1. To analyze both reversible, high-frequency phenotypic switching and mating type switching at sites of colonization, primary samples from the oral cavities and vaginal canals of three patients suffering from C. glabrata vaginitis were clonally plated on agar containing CuSO(4). It was demonstrated that (i) in each vaginitis patient, there was only one colonizing strain; (ii) an individual could have vaginal colonization without oral colonization; (iii) phenotypic switching occurred at sites of colonization; (iv) the DB phenotype predominated at the site of infection in all three patients; (v) genetically unrelated strains switched in similar, but not identical, fashions and caused vaginal infection; (vi) different switch phenotypes of the same strain could simultaneously dominate different body locations in the same host; (vii) pathogenesis could be caused by cells in different mating type classes; and (viii) mating type switching demonstrated at both the genetic and transcription levels occurred in one host.

Topics: Agar; Candida glabrata; Candidiasis, Oral; Candidiasis, Vulvovaginal; Culture Media; DNA Fingerprinting; Female; Fungal Proteins; Gene Expression Regulation, Fungal; Genes, Fungal; Genes, Mating Type, Fungal; Humans; Mouth; Phenotype; Vagina

To establish the best method for boric acid susceptibility testing, we compared two agar dilution methods (high and low inoculum) and a standard broth microdilution method (from the National Commitee for Clinical Laboratory Standards document NCCLS M-27A). Saccharomyces cerevisiae (37) and non-C. albicans Candida (39) isolates, as well as one isolate of Trichosporon sp., were included. All were isolated from female workers with vulvovaginitis. Good agreement within a fourfold dilution range was found between the three methods, and only the broth microdilution method versus the agar dilution method with high inoculum showed significant discrepancies. Reading results was easier with the broth microdilution method than with the agar dilution methods because of partial growth inhibition in the latter. In conclusion, broth microdilution is a suitable method for testing yeast susceptibility to boric acid.

Topics: Agar; Anti-Infective Agents, Local; Antifungal Agents; Boric Acids; Candida; Candidiasis, Vulvovaginal; Culture Media; Female; Humans; Microbial Sensitivity Tests; Mycoses; Saccharomyces cerevisiae; Trichosporon; Vulvovaginitis

To investigate if introital and vaginal flushing samples inoculated on chromogenic agar could increase the recovery rate and rapid identification of Candida and non-albicans species, as compared to culture of posterior vaginal fornix samples on Sabouraud agar and speciation of isolates by biochemical tests.. Samples from the introitus and the posterior vaginal fornix and vaginal lavage samples were collected from 91 women with a history suggestive of recurrent vulvovaginal candidosis (RVVC), and with a suspected new attack of the condition. The specimens were cultured on Sabouraud and CHROMagar. Speciation of yeast isolates was made on the chromogenic agar by API 32C kits and by an atomized system (Vitek).. Forty-six (51%) women were positive for Candida from one or more of the samples. The introital cultures were positive in 43 (47%) women, both on Sabouraud and chromogenic agar. From the posterior vaginal fomix, 42 (46%) women were positive on the Sabouraud and 43 (47%) on chromogenic agar cultures, while the vaginal lavage cultures yielded Candida on those two media in 40 (44%) and 41 (45%) cases, respectively. Candida albicans was the most frequent species recovered, from 40 (87%) cases, followed by C. krusei in 4 (9%), C. glabrata in 2 (4%), and C. parapsilosis in one case. There was only one woman who had a mixed yeast infection, by C. albicans and C. krusei. There was only one discrepancy in the speciation as demonstrated by mean of chromogenic agar and API 32C kit.. Neither cultures of introital nor of vaginal lavage samples increases the detection rate of Candida in RVVC cases as compared to cultures of posterior vaginal fornix samples. Use of chromogenic agar is a convenient and reliable means to detect colonization by Candida and differentiate between C. albicans and non-albicans species.

Topics: Agar; Candida; Candida albicans; Candidiasis, Vulvovaginal; Chromogenic Compounds; Female; Humans; Therapeutic Irrigation; Vagina

Two plant products, Euphorbia hirta leaves and fruits of Musa sapientum, were evaluated as principal ingredients for selective cultivation of fungi. Sapientum glucose agar supported the growth of both dermatophytic, yeast-like, and saprophytic fungi; growth on this medium compared favourably with growth on Sabouraud glucose agar, a standard mycological medium. Sporulation and pigment formation were stronger on sapientum glucose agar than on Sabouraud glucose agar, although fungal growth on the latter was more luxuriant. Addition of Euphorbia extract to mycological media remarkably enhanced fungal growth on the media, and concomitantly suppressed bacterial growth to a similar extent as did antibiotics. The results of this study suggest that Euphorbia sapientum glucose agar can safely be recommended as a cheap and efficient medium for routine isolation of fungi in both clinical and general mycological studies.

Topics: Agar; Candida; Candidiasis, Vulvovaginal; Culture Media; Dermatomycoses; Euphorbiaceae; Female; Fungi; Humans; Mycology; Plant Extracts; Plant Leaves; Zingiberales

A new CHROMagar selective medium (Becton Dickinson) was tested. Strains of Candida species isolated after 48 hours were identified by specific dying of the colonies on the selective medium. The inoculation data were verified by filamentation and fermentation tests. No differences were found. Together with the most frequently isolated species C. albicans, in 20% of the cases we found C. glabrata considered recently as a cause of the recurrent vaginal candidosis with ketoconazole and 5-flucytosine resistant strains.

Topics: Adolescent; Adult; Agar; Candida; Candidiasis, Vulvovaginal; Child; Culture Media; Female; Humans; Middle Aged; Recurrence; Vagina

Topics: Agar; Candida; Candidiasis, Vulvovaginal; Culture Media; Diagnosis, Differential; Edible Grain; Female; Humans; Methods; Pigmentation; Staining and Labeling; Vaginal Smears