Incidence of motile, curved anaerobic rods (Mobiluncus species) in vaginal secretions

Aerobic and anaerobic cultures as well as a Gram stain and wet mount preparation were made of vaginal swabs taken from various groups of women including those with vaginal discharge. The bacteria commonly found in cultures were lactobacilli, coryneforms, Staphylococcus epidermidis and facultative streptococci. Anaerobes were isolated from 75% (475 of 632) of specimens. The incidence of Trichomonas vaginalis, Candida species, Gardnerella vaginalis and Mobiluncus species in the five groups of women varied from 2.2-5.1%, 11.5-35.7%, 23.3-36.7% and 20.0-34.8% respectively. Except for Candida species, differences in the prevalence of these organisms between the groups of women were not significant. The isolation rates of Candida species in women attending the antenatal clinic and staff health clinic were significantly higher than women in the other groups. Mobiluncus species were found to occur either with T. vaginalis, Candida species or G. vaginalis alone or with any two or with all three or in the absence of these organisms. However, the incidence of Mobiluncus species was significantly higher in women colonized with G. vaginalis (112 of 185, or 60.5%) compared with women not infected (47 of 477, or 9.8%). Also, Mobiluncus species occurred in large numbers when found in the presence of G. vaginalis. When found without G. vaginalis, Mobiluncus species occurred in much smaller numbers. As with G. vaginalis, Mobiluncus species also occurred concomitantly with certain anaerobes, mainly Bacteroides species and peptostreptococci.