Prevalence of specific and phylogenetically closely related genotypes in the population of Candida albicans associated with genital candidiasis in China

Genitourinary candidiasis, which is most frequently caused by Candida albicans, is a common problem worldwide. The pathogenesis of the infection, especially recurrence of the infection, remains to be elucidated. This study analyzed 199 independent Chinese C. albicans isolates using multilocus sequence typing (MLST) and microsatellite typing, with the focus on the isolates associated with vulvovaginal candidiasis (VVC) of Chinese women. MLST data of 221 vaginal isolates from other countries available from the consensus MLST database of C. albicans were retrieved for comparison. A total of 124 diploid sequence types (DSTs) were recognized from the Chinese C. albicans isolates, among which, 98 (79.0%) have not been reported in the MLST database of the species. The majority of the VVC (71.6%) and balanitis (92.3%) isolates from China were located in clade 1 of C. albicans; while only 40.6% of the vaginal isolates and 7.8% of the oral isolates from healthy volunteers were found in the same clade. Furthermore, 69.1% of the VVC and 84.5% of the balanitis isolates concentrated in a cluster of clade 1 with DST 79 as the primary founder. The isolates in this cluster possessed microsatellite genotypes CAI 30-45, CAI 32-46 and their close derivatives. Interestingly, a remarkable difference in genotype distribution patterns between Chinese and non-Chinese vaginal isolates of C. albicans was observed. Only 11.3% of the non-Chinese vaginal isolates compared were located in the cluster concentrated with Chinese VVC isolates. The results suggest significant association of specific and genetically similar genotypes with genital infections in China.