Molecular epidemiological characteristics of Candida glabrata isolated from vulvovaginal candidiasis

Objective: To investigate the molecular epidemiological characteristics of Candida glabrata (C. glabrata) population isolated from vulvovaginal candidiasis (VVC) in Suzhou, and to provide epidemiological evidence for the prevention and treatment of VVC. Methods: A total of 132 isolates of C. glabrata were collected from patients diagnosed as VVC in the people's hospital of SND from January to December 2021. Multilocus sequence typing (MLST) involving six housekeeping genes was uesd for sequence tpying (STs). Wright's fixation index (Fst), Tajima's D, and Fu's & Li's Fs neutral tests were calculated for analysis of population genetic diversity. Results: A total of 37 STs were identified among 132 C.glabrata isolates.ST7 was dominant sequence type, accounting for 47.0% (62/132 isolates), and 56.8% (21/37 STs) were singleton sequence types.According to NCBI sequence type database, 67.6% (25/37 STs) of the sequences appeared for the first time, namely newly defined sequence types, 76% (19/25 STs) of which were singleton sequence types. ST7 was the main sequence type in different clinical types of C. glabrata isolated from VVC. The genetic diversity among 3 populations of VVC, RVVC, and colonized C. glabrata showed that the genetic difference of the housekeeping gene UGP1 between MLST STs analysis was small, but the genetic difference between the pathogenic population (VVC/RVVC) and the colonized population was moderate (Fst:0.05483-0.11314). Conclusion: The C. glabrata population isolated from patients with VVC in Suzhou exhibits high genetic diversity and obvious regional characteristics, indicating the special environmental pressure selection in Suzhou, and providing epidemiological evidence for the precise prevention and treatment of VVC.