Bacteriology of the vagina.

Interest in the microflora of the vagina and cervix has stemmed from the recognition of its significant association with vaginal and upper genital tract infections. Yet a clear understanding of the range of microbial types which are consistent with a normal genital tract and the factors which control the flora are elusive. Different methods and study populations in the various studies of the vaginal flora often have produced divergent conclusions. Studies using improved bacteriologic culture techniques, however, indicate that the previously held assumptions (i) that lactobacilli are the only bacteria present in healthy women, and (ii) that Gardnerella vaginalis is the only species associated with bacterial vaginosis, were oversimplifications. Although the aerobic and anaerobic species isolated are similar, qualitatively speaking, there are marked quantitative differences in the flora between these two groups of women. Lactobacilli in high concentrations are the most prevalent species in the vagina of women without bacterial vaginosis, whereas lactobacilli are less prevalent, and anaerobes, mycoplasma, and G. vaginalis are more prevalent, and in higher concentrations, in the vagina of women with bacterial vaginosis.