Adherence of vaginal and pharyngeal strains of group B streptococci to human vaginal and pharyngeal epithelial cells.

In vitro tests for adherence to human vaginal and pharyngeal epithelial cells were used to study the problem of tissue-specific tropism in group B streptococci (GBS). Twenty-two vaginal or pharyngeal clinical isolates of GBS (serotypes Ia, Ib, II, and III) were used. No significant differences in adherence to vaginal and pharyngeal epithelial cells were found between GBS from both sources: statistical analysis furnished no evidence for tissue-specific tropism. Serotype III vaginal GBS adhered better to vaginal and pharyngeal epithelial cells than did serotype III GBS strains isolated from the pharynx. However, pronounced differences in the level of adherence were found among strains of the same serotypes and from the same sources. Thus, the results obtained suggest that differences in adherence may rather be strain-dependent that type-dependent.