Dissimilarity in the occurrence of Bifidobacteriaceae in vaginal and perianal microbiota in women with bacterial vaginosis.

Recent data point at the similarity between the perianal and vaginal microflora in terms of Lactobacillus species involved. Bacterial vaginosis, the most common perturbation of the vaginal microflora involving primarily overgrowth of Gardnerella vaginalis, has also been suggested to involve a recto-vaginal pathway. We addressed this issue with regard to bacteria of the Bifidobacteriaceae family. In particular, we investigated the putative concordance of the presence of G. vaginalis and a series of Bifidobacteria between the perianal and vaginal microflora in 10 patients with bacterial vaginosis through multicolor fluorescence in situ hybridization analysis of desquamated epithelial cells. G. vaginalis was found in a biofilm mode of growth at the perianal and vaginal sites. In most women at least one of the following species was detected perianally: Bifidobacterium adolescentis, Bifidobacterium longum, Bifidobacterium breves, Bifidobacterium bifidum and Bifidobacterium catenulatum. At the vaginal site, none of these Bifidobacteria was found. We conclude that bacterial vaginosis does not occur as a result of simple growth per continuum of perianal bacteria. Only some species originating from the intestinal tract do display pronounced vaginotropism, like G. vaginalis, whereas many other species do not.