Vaginal Colonization With GBS Clinical Trial
Official title:
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.
Four specific tasks will be addressed to:
(i) Understand whether and how the gut microbiota may influence growth and colonization of
GBS CC-17 within the intestine of neonates.
(ii) Study the contribution of different diets and immune system constituents enabling the
persistence of GBS CC-17 in the gut of neonates.
(iii) Determine whether the adaptive immune response elicited by maternal GBS colonization
and transmitted to the infant is different for GBS CC-17 versus non-CC-17 GBS.
(iv) Determine whether or not GBS strains isolated from the mothers and from their babies are
identical and whether the environment (ie. the vagina or the milk for the mother, the
intestine or the oral cavity for the baby) influence the expression of specific virulence
factors of CC-17.
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