Susceptibility and molecular characterization of Candida species from patients with vulvovaginitis

Abstract

Vulvovaginal candidiasis affects women of reproductive age, which represents approximately 15-25% 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.

Keywords: In vitro susceptibility; Variability genetic; Vulvovaginal candidiasis.

Fig. 1

The phylogenetic tree of maximum likelihood based on the alignment of the entire region of its1/its2 and D1/D2 was built using 100 bootstrap, using the evolutionary model Tamura-3 parameters with program Mega version 5.1. Schizosaccharomyces pombe was used as an outgroup. The tree showed 6 clades (Albicans; Dubliniensis; Guilliermondii, Saccharomyces; Kefyr; Glabrata) diversified according to the isolated species. For a thorough understanding, the evaluated groups in this study are represented by colored squares for discernment: the brown square refers to the colonized group; one red square indicates isolates from the uncomplicated infection group; the two red squares represent the group with complicated infection.

Fig. 2

Agarose electrophoresis ABC genotyping of the C. albicans from the different studied groups, genotype A (C. albicans – 450 bp) and B (C. albicans – 840 bp). The lanes 2–14 correspond to the colonized group; 15–23 to the uncomplicated infection group and 24–33 to the complicated infection group. Lane 34 represents a blank; the lanes 1 and 35 indicate standard 1 kb molecular weight markers (Invitrogen, Carlsbad, Ca, USA).