Influence of environmental and genotypic factors on biofilm formation by clinical isolates of group B streptococci.

Group B Streptococcus (GBS) colonizes the gastrointestinal and urogenital tracts of approximately 30% of women, and it can cause sepsis and meningitis in neonates. GBS has been shown to form biofilms in vitro, but the effects of environmental and genotypic factors upon GBS biofilm formation are unclear. The aim of the present study was to optimize culture conditions for enhanced GBS biofilm production. Furthermore, this study also investigated the influences of strain lineage, pilus profile, and isolation source on GBS biofilm formation. The results demonstrate that the fed-batch mode and acidic pH strongly enhanced GBS biofilm formation in vitro. These findings suggest that the fed-batch mode may be suitable for both screening and fundamental studies of GBS biofilm formation. Moreover, this study demonstrated a correlation between the hyper virulent clonal complex 17 and a strong biofilm phenotype.