Integrative Approach to Identify Environmental Risk Factors for CC-17 Group B Streptococcal Neonatal Infection

Streptococcus agalactiae (GBS) is the leading cause of neonatal septicaemia, meningitis, and pneumonia in the industrialized world. Early onset (EOD) and late onset (LOD) diseases are defined in neonates by their occurring within or after the first week of life, respectively. Molecular epidemiological studies have identified a capsular serotype III clone, referred to as CC-17 by Multi Locus Sequence Typing, as accounting for the vast majority of neonatal invasive diseases and for almost all cases of meningitis in LOD. The investigators working hypothesis is that host-environmental interactions may contribute to the colonization and persistence of the hypervirulent CC-17 GBS in the neonate. In this project the investigators will determine if reciprocal interactions between the intestinal microbiota and the innate and adaptive immune system may specifically facilitate the colonization of the neonate by the hypervirulent GBS CC-17 clone.