Prevalence of Candida spp. in cervical-vaginal samples and the in vitro susceptibility of isolates

Vulvovaginal candidiasis (VVC) is an infection of the genital mucosa caused by different species of the genus Candida. Considering the lack of data on this topic in the south of Brazil, this study aimed to assess the prevalence of Candida spp. in the cervical-vaginal mucosa of patients treated at a university hospital in southern Rio Grande do Sul, as well as the etiology and the susceptibility of the isolates against fluconazole, itraconazole, miconazole and nystatin. Samples were collected at the gynecology clinic of the Federal Hospital of the University of Rio Grande, and the isolates were identified using phenotypic and biochemical tests. The susceptibility analysis was performed according to the CLSI M27-A2 protocol. Of the 263 patients included, Candida spp. was isolated in 27%, corresponding to a prevalence of approximately 15% for both VVC and colonization. More than 60% of the isolates were identified as Candida albicans; C. non-albicans was isolated at a rate of 8.6% in symptomatic patients and 14.3% in asymptomatic patients. The prevalence of resistance against fluconazole and itraconazole was 42% and 48%, respectively; the minimal inhibitory concentration of miconazole ranged from 0.031 to 8 µg/mL, and that of nystatin ranged from 2 to >16 µg/mL. The high rate of resistance to triazoles observed in our study suggests the necessity of the association of laboratory exams to clinical diagnosis to minimize the practice of empirical treatments that can contribute to the development of resistance in the isolates.(AU)

Susceptibility and molecular characterization of Candida species from patients with vulvovaginitis

Vulvovaginal candidiasis affects women of reproductive age, which represents approximately 1525% of vaginitis cases. The present study aimed to isolate and characterize yeast from the patients irrespective of the presentation of clinical symptoms. The isolates were subjected to in vitro susceptibility profile and characterization by molecular markers, which intended to assess the distribution of species. A total of 40 isolates were obtained and identified through the CHROMagar, API20aux and by ITS and D1/D2 regions sequencing of DNAr gene. Candida albicans strains were genotyped by the ABC system and the isolates were divided into two genotypic groups. The identity of the C. albicans, C. glabrata, C. guilliermondii, C. kefyr and Saccharomyces cerevisiae isolates was confirmed by the multilocus analysis. The strains of Candida, isolated from patients with complications, were found to be resistant to nystatin but sensitive to fluconazole, amphotericin B and ketoconazole, as observed by in vitro sensitivity profile. The isolates from asymptomatic patients, i.e., the colonized group, showed a dose-dependent sensitivity to the anti-fungal agents, fluconazole and amphotericin B. However, the isolates of C. albicans that belong to distinct genotypic groups showed the same in vitro susceptibility profile.(AU)

Candida species biofilm and Candida albicans ALS3 polymorphisms in clinical isolates

Over the last decades, there have been important changes in the epidemiology of Candida infections. In recent years, Candida species have emerged as important causes of invasive infections mainly among immunocompromised patients. This study analyzed Candida spp. isolates and compared the frequency and biofilm production of different species among the different sources of isolation: blood, urine, vulvovaginal secretions and peritoneal dialysis fluid. Biofilm production was quantified in 327 Candida isolates obtained from patients attended at a Brazilian tertiary public hospital (Botucatu, Sao Paulo). C. albicans ALS3 gene polymorphism was also evaluated by determining the number of repeated motifs in the central domain. Of the 198 total biofilm-positive isolates, 72 and 126 were considered as low and high biofilm producers, respectively. Biofilm production by C. albicans was significantly lower than that by non-albicans isolates and was most frequently observed in C. tropicalis. Biofilm production was more frequent among bloodstream isolates than other clinical sources,in urine, the isolates displayed a peculiar distribution by presenting two distinct peaks, one containing biofilm-negative isolates and the other containing isolates with intense biofilm production. The numbers of tandem-repeat copies per allele were not associated with biofilm production, suggesting the evolvement of other genetic determinants.

Vulvovaginal candidiasis in Mato Grosso, Brazil: pregnancy status, causative species and drugs tests

Causative agent in majority of VVC is Candida albicans, but infection due to non-C. albicans is common. Use of empiric antifungal therapy in Brazil due to syndromic management of vulvovaginitis could act as risk factor for increase resistance among VVC causative agents. From Mato Grosso patients, 160 with culture-proved among 404 women who had clinical symptoms of VVC, were enrolled in this study. 70 non-pregnant women and 90 pregnant women were included. Candida albicans was the most prevalent, representing 72.9% in the non-pregnant group and 92.3% in the pregnant group. Differences in species distribution were noted between the two groups, being C. parapsilosis the second more prevalent species among non-pregnant women. Susceptibility testing revealed high susceptibility to fluconazole (except for C. krusei), itraconazole, ketoconazole, and amphotericin B regardless the species (C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, C. krusei) analyzed.

Lack of association between genotypes and virulence factors in C. albicans strains isolated from vaginal secretion

The physiopathogenesis of vulvovaginal candidiasis (VVC) is still not completely elucidated. The objective of this study was to evaluate if there is a relationship between the different genotypes of Candida albicans, their main agent and the virulence of this yeast in vaginal isolates, and to check if there are laboratorial markers that can predict the ability of each isolate to develop VVC independently of symptoms. The production of exoenzymes protease, phospholipase and haemolysin, resistance to hydrogen peroxide, and the genotype were determined. Genotype A was predominant (75%), protease, phospholipase and haemolytic activity were highly expressed, and the majority of the yeasts were sensitive to H2O2 in 1 and 2 hours of exposure, suggesting that these factors are important in the virulence of vaginal isolates. However they did not have any correlation with the genotypes. The different isolates expressed similar virulence potential, suggesting that other factors relating to the yeasts and the host must participate in the development of the clinical disease.

A fisiopatogenia da candidíase vulvovaginal (CVV) não está completamente elucidada até o presente momento. O objetivo deste estudo foi avaliar se exite relação entre os diferentes genótipos de Candida albicans, seu principal agente, e a virulência desta levedura em isolados vaginais, e checar se existem marcadores laboratoriais que possam predizer a habilidade de cada isolado para desenvolver CVV independentemente dos sintomas. Foram determinados a produção de exoenzimas protease, fosfolipase and hemolisina, resistência ao peróxido de hidrogêncio, e genótipo. O genótipo A foi predominante (75%), protease, fosfolipase e atividade hemolítica foram alevadamente expressos, e a maioria das leveduras foram sensíveis ao H2O2 em 1 e 2 horas de exposição, sugerindo que estes fatores são importantes na virulênciae de isolados vaginais. Entretanto, não houve nenhuma correlação com os genótipos. Os diferentes isolados expressaram potencial de virulência similares, sugerindo que outros fatores relacionados às leveduras e ao hospedeiro devem participar no desenvolvimento da doença clínica.