Mobiluncus gen. nov., Mobiluncus curtisii subsp. curtisii sp. nov., Mobiluncus curtisii subsp. holmesii subsp. nov., and Mobiluncus mulieris sp. nov., Curved Rods from the Human Vagina

Abstract

A total of 22 strains of curved, anaerobic bacteria from the vaginae of women with bacterial vaginosis were found to be morphologically, biochemically, and genetically distinct from species in previously described genera. We placed these organisms in the genus Mobiluncus gen. nov., which includes curved, anaerobic, motile, rod-shaped bacteria that have multiple subpolar flagella and multilayered gram-variable cell walls, produce succinate and acetate, are stimulated by rabbit serum, and have guanine-plus-cytosine contents of 49 to 52 mol%. Mobiluncus curtisii is the type species (type strain, ATCC 35241). Mobiluncus curtisii strains are small (length, 1.7 μm) and gram variable, are stimulated by arginine, and produce ornithine, citrulline, and ammonia from arginine. Six of these strains migrate through soft (0.25%) agar and are nitrate negative, and these organisms are designated Mobiluncus curtisii subsp. curtisii. Six strains that do not migrate through soft agar and are nitrate positive are designated Mobiluncus curtisii subsp. holmesii (type strain, ATCC 35242). A total of 10 strains are designated Mobiluncus mulieris (type strain, ATCC 35243). These organisms are large (length, 2.9 μm) and gram negative, produce acid (pH 75% within and ≤25% between strains of the two species.