Correlation between genotypes and antifungal susceptibility profiles of Candida isolates from pregnant and non-pregnant women in South Africa

Abstract

Vulvovaginal candidiasis (VVC) is a common vaginal infection, affecting up to 75% of women of reproductive age at some point in their lives. The leading cause of VVC is Candida albicans (C. albicans). This study investigates the correlation between genotypes and antifungal susceptibility profiles of Candida isolates collected from pregnant and non-pregnant South African women. A total of 72 Candida isolates were identified using the Applied Biosystems TaqMan assay and confirmed via germ tube tests and polymerase chain reaction (PCR). All isolates (100%) were identified as C. albicans. ABC genotyping revealed that 62.5% of isolates were genotype A, 26.4% were genotype B, and 11.1% were genotype C. Antifungal susceptibility testing using the Sensititre™ YeastOne™ YO10 AST Plate assessed minimum inhibitory concentrations (MIC) for anidulafungin, caspofungin, fluconazole, micafungin, and voriconazole. Fluconazole showed the highest resistance rate at 13.9%, while 86.1% of isolates remained susceptible. Genotype A predominated among isolates resistant to anidulafungin, fluconazole, micafungin, and voriconazole. All caspofungin-resistant isolates were genotype C. Genotype B exhibited no resistance to any antifungals tested, indicating the lowest virulence among the genotypes. These findings suggest that genotypes A and C have higher resistance profiles, emphasising the need for routine VVC screening and resistance surveillance to inform effective Candida infection management.