Phenotypic and genotypic study of Streptococcus agalactiae in vagina of pregnant women in Argentina

Streptococcus agalactiae (GBS) is a leading cause of serious neonatal infec tion. In this study we determine the prevalence, serotype distribution and genomic diversity of GBS in vagina of pregnant women. Vaginal swabs of 531 pregnant women were cultured on Columbia Agar Base Blood, GBS Agar Base and Todd Hewitt Broth. GBS were characterized by group and type-specific agglu tination. Genomic polymorphism was studied by random amplification of DNA ( RAPD). Seventeen patients (3.2%) were positive for GBS, resulting serotype III the most frequent. RAPD detected 18 different RAPD profiles from 21 GBS studied, revealing a good discriminatory power. In this sense, this method showed different genotype from GBS serotype III recovered from successive samples of two patients, suggesting reinfection. In conclusion, the combina tion of RAPD and serotyping appear promising for epidemiological studies. F inally, findings of reinfection after therapy during pregnancy, led us to s uggest performing prenatal GBS screening and intrapartum prophylaxis in ord er to reduce neonatal risk.