Cyclic variation in the adherence of group B streptococci to human vaginal epithelial cells.

Studies conducted on three normally menstruating women demonstrated a distinct cyclic variation in adherence of group B streptococcus type III to vaginal epithelial cells. This cyclic variation consisted of a gradual rise in adherence during the first half of the menstrual cycle, reaching a maximum on day 14, followed by a sharp decline to low levels of adherence that persisted through the second half of the cycle. These changes in adherence correlated directly with the variation in the pyknotic index of the vaginal epithelial cells, suggesting that hormonal factors played a role in adherence of group B streptococci to vaginal epithelium.