Group B Streptococcus (GBS) is a leading cause of neonatal disease. Mothers are the main source for newborn colonization since this microorganism can be found in the anovaginal tract of 40% of pregnant women. The only currently available tool to prevent GBS neonatal infections is the intrapartum antibiotic prophylaxis. However, this approach may contribute to the emergence of antimicrobial-resistant GBS isolates and/or multidrug-resistant bacteria (MDR) such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and carbapenem-resistant enterobacteria (CRE), which can also colonise the anovaginal tract of pregnant women.
Although GBS and MDR can share this habitat, it is still unknown if they can present mutual interference. GBS vaccines based on capsular polysaccharides are currently in advanced development, but their impact in the anovaginal microbiota, especially in MDR, and potential coverage in many LMIC, including Brazil, are still unknown. There are 10 different GBS capsular types, but vaccines are being developed against 5 or 6; thus, estimating vaccine coverage in different countries is important.
Considering the imminence of a GBS capsular-based vaccine, the lack of information on GBS-related characteristics in Brazil, and the potential interrelationship between GBS and MDR in the anovaginal microbiota, this proposal aims to evaluate coverage and impact of a future GBS vaccine by collecting data on capsular types and antimicrobial resistance of GBS isolates circulating in Brazil, estimating correlate of protection (with opsonophagocytic killing assay) of current vaccine proposals, and predicting the potential impact in the interrelationships between GBS and major MDR in the anovaginal tract of pregnant women.