Multilocus sequence typing of Candida africana from patients with vulvovaginal candidiasis in New Delhi, India

Abstract

We investigated the prevalence of vulvovaginal candidiasis due to C. africana in an STD clinic in India and analysed the genetic relatedness of these C. africana isolates with those outside India. A total of 283 germ-tube-positive yeasts were identified by VITEK2. Molecular characterisation of all isolates was carried out by hwp1-gene-specific PCR. Of 283 germ-tube-positive yeast isolates, four were identified as C. africana using hwp1-gene-specific PCR. All hwp1 PCR positive C. africana were subjected to antifungal susceptibility testing, ITS and D1/D2 region sequencing and were typed by using MLST approach. Similar to C. africana isolates from the United Kingdom and unlike those from Africa, the Indian C. africana grew at 42°C. Sequencing of eight gene fragments in MLST identified all four strains to have different genotypes not reported previously. Furthermore, though the Indian C. africana isolates were susceptible to most of the 14 tested antifungal drugs, differences in susceptibility were observed among the four strains. Our results indicate genetic and phenotypic heterogeneity among C. africana from different geographical regions. Due to lack of data on epidemiology and genetic variability of this under-reported yeast, more studies using molecular methods are warranted.

Keywords: Candida africana; India; antifungal susceptibility testing; multilocus sequence typing; vulvovaginal candidiasis.