Selenium Exerts Antimicrobial Activity against the Perinatal Pathogen Streptococcus agalactiae and Perturbs Bacterial Interactions with Human Gestational Membranes

(GBS) is a Gram-positive, encapsulated, pathogenic bacterium. GBS causes severe perinatal infections that lead to chorioamnionitis, funisitis, premature rupture of membranes, preterm birth, maternal sepsis, neonatal sepsis, stillbirth, and maternal demise. Epidemiological data indicate that the nutrient selenium provides protection against infection and adverse disease outcomes and is a critical nutrient for development of a healthy pregnancy. We hypothesized that selenium could have antimicrobial activity against GBS. To test this, we employed a panel of colonizing and invasive GBS strains and evaluated the bacterial growth in response to selenium exposure. Our results indicate that selenium can inhibit GBS growth and adherence to gestational tissues and that colonizing strains are more sensitive to selenium than invasive strains. Together, these results indicate that selenium could be deployed as a cost-effective intervention to ameliorate the risk of GBS perinatal infections.