Bacterial vaginosis is not a transmitted disease, but is the result of massive overgrowth of mixed flora, including peptostreptococci, Bacteroides spp., Gardnerella vaginalis, Mobiluncus spp., and genital Mycoplasma. There’s little inflammation, and the disorder represents a disturbance of the vaginal microbial ecosystem rather than a true infection of tissues. No single bacterial species is responsible for bacterial vaginosis. The cause of the overgrowth with anaerobes such as Gardnerella, Mycoplasma and Mobiluncus spp. is unknown.