Virulence is one of the mechanisms of vulvovaginal candidiasis recurrence, rather than drug resistance

To explore the mechanism of vulvovaginal candidiasis (VVC) recurrence. A total of 127 strains of Candida albicans (C. albicans) were collected, including 58, 40, and 29 strains from the recurrent vulvovaginal candidiasis (RVVC), VVC, and asymptomatic carrier (AC), respectively. The strains' virulence such as in vivo hypha formation rate, germ tube formation rate, biofilm formation ability, and sensitivity to five common antifungals were detected. The in vivo hypha formation rates of C. albicans from the RVVC (55.2%) and VVC (40.0%) were significantly higher than that from the AC (0%) (P < .001). The median germ tube formation rate of the RVVC was 88.2%, which was higher than that of the VVC and AC (59.9% and 65.6%), respectively (P < .001). The median absorbance of the biofilm formation test for strains in the RVVC was 0.380, considerably higher than that in the VVC and AC (0.246 and 0.254) (P < .001). The drug sensitivity rate of the strains to 5-fluorocytosine and itraconazole and the ratio of strains sensitive to all the five antifungals in the VVC group were lower than those in the RVVC and AC groups. In conclusion, the virulence of strains from the RVVC is stronger than that of strains from the VVC and AC, the antifungal resistance rate of strains from the RVVC group is lower than that of strains from the VVC group. So, it is suitable to argue that the strains' virulence is one of the mechanisms for the relapse of RVVC, rather than its antifungal resistance.The virulence of strains from recurrent vulvovaginal candidiasis (RVVC) is stronger than that from vulvovaginal candidiasis (VVC) and asymptomatic carrier (AC), but the drug resistance rates are opposite. Virulence is one of the mechanisms of the relapse of RVVC, rather than drug resistance.