Modulation of group B Streptococcus infection and vaginal cell inflammatory signaling in vitro by Lactobacillus crispatus -loaded electrospun fibers

Vaginal colonization by Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a major risk factor for ascending infections, preterm birth, and neonatal sepsis. Current GBS prevention efforts include routine GBS perinatal screening and intrapartum antibiotic prophylaxis, which decrease the rate of early-onset neonatal sepsis, but have drawbacks that include impacting the infant's developing microbiome. Lactobacillus-dominant vaginal microbiomes provide protection against pathogens such as GBS, and using probiotics as an antibiotic-free approach to limit GBS colonization is of increasing interest. In this study, we investigated the ability of Lactobacillus crispatus-loaded electrospun fibers to deliver live L. crispatus cells in an in vitro vaginal epithelial cell model, modulate GBS infection establishment and persistence, and alter vaginal cell inflammatory signaling. Our data demonstrate that electrospun fibers deliver viable L. crispatus to the surface of vaginal epithelial cells and that L. crispatus modulates vaginal cell inflammatory signaling by decreasing inflammatory IL-8 release and increasing anti-inflammatory IL-1RA secretion during established GBS infection. Treatment of pre-established GBS infection with electrospun fibers with or without L. crispatus decreased GBS burden at 24 hours, suggesting L. crispatus-dependent and -independent anti-GBS activity, and L. crispatus elicited an anti-inflammatory response via IL-1RA release. Overall, the data highlight the potential of electrospun fibers as a feasible probiotic delivery platform with antibacterial activity against GBS and which provides commensal lactobacilli capable of modulating host-pathogen interactions and inflammatory signaling of the vaginal epithelium.