[Recent bacteriologic data: from physiopathology to treatment].

Bacterial vaginosis is characterized by a change in the vaginal ecosystem in which Lactobacillus spp, the dominant members of the normal flora, are replaced by an association of various bacterial species including Gardnerella vaginalis, anaerobes (Bacteroides spp, Prevotella spp, Porphyromonas spp, Peptostreptococcus spp and Mobiluncus spp) and Mycoplasma hominis. The reasons for this imbalance are unknown, although the loss of lactobacilli that produce hydrogen peroxide (which is toxic for G. vaginalis and numerous anaerobes) may be an essential element. The introduction of one or several of these species into the vagina (they can occasionally be isolated in small numbers even in the absence of vaginosis) following intercourse or from the intestinal tract may also play a role. G. vaginalis itself is not considered to cause vaginosis, but is almost always present and multiplies rapidly; in addition, it has a high capacity for adherence to epithelial cells both in vivo and in vitro. It is now agreed that the concomitant growth of one or several anaerobic species is required for bacterial vaginosis to develop. Our knowledge of the bacteriology of bacterial vaginosis has implications for diagnosis and treatment. It is now possible to obtain a precise bacteriologic diagnosis, not by culturing G. vaginalis (a costly and low-yield procedure), but by direct examination of the vaginal flora after Gram staining, which shows the replacement of lactobacilli by a characteristic polymorphic flora. Therapy is based on the use of antibiotics such as the imidazoles, which are active against G. vaginalis and anaerobes, but not against the commensal lactobacilli.(ABSTRACT TRUNCATED AT 250 WORDS)