Biology
Originally, G. vaginalis was implicated in bacterial vaginosis by Gardner and Dukes and named Haemophilus vaginalis [1, 2]. After further analysis of the organism, Greenwood and Pickett placed it in its own genus, and changed the name to Gardnerella vaginalis [3]. This differentiation was subsequently supported by DNA-DNA hybridization [4]. Gardnerella is in the Family Bifidobacteriaceae and the most closely related genus that has been characterized is Bifidobacterium. G. vaginalis are small, nonmotile, pleomorphic rods, which may be piliated. The gram stain reaction depends upon growth conditions but electron microscopy and the lack of lipopolysaccharide production demonstrate that the cell envelope is gram-positive [5, 6]. G. vaginalis is a fastidious anaerobe and requires complex medium for growth. Studies using metabolic methods of identification indicate that it is catalase-negative, exhibits a-glucosidase activity, starch hydrolysis, hippurate hydrolysis, acid phosphatase activity, but lacks gelatin and esculin hydrolysis, and salt tolerance [5]. G. vaginalis ferments dextrin, fructose, glucose, maltose, ribose, starch, and sucrose; and some strains ferment mannose, galactose, xylose and trehalose [5].
In this work we have sequenced and analysed the genomes of two G. vaginalis strains, one from a healthy woman (strain 5-1) and one from a woman diagnosed with bacterial vaginosis (strain AMD). We have found significant genomic divergences and in vitro-tested disparities in the virulence potential of the two strains.