Interactions between Streptococcus agalactiae, Candida albicans, and human vaginal epithelial cells

During pregnancy, colonization can trigger adverse outcomes and neonatal invasive infection. Using an adapted murine model of vaginal colonization, we show that the human pathobiont Candida albicans supports GBS fitness in the vaginal tract and ascension to the uterus.

C. albicans positively associates with GBS across several human studies, and C. albicans and GBS physically interact in a mouse co-colonization model. This co-colonization contributes to GBS persistence in the vagina, cervix, and uterus and facilitates antibiotic evasion. Across clinical isolates, the hyphal form of C. albicans promotes GBS aggregation and adhesion to host epithelial cells.