Study: Subtypes of G. vaginalis

Scientists have looked into the different subspecies of G. vaginalis in women with both bacterial vaginosis and healthy vaginas using a novel approach that can establish Gardnerella vaginalis identification, quantification and subtyping in non-cultured vaginal specimens.

G. vaginalis bacterial loads were analysed from 60 clinical swabs. A high pathogen prevalence was found not only amongst the women with BV (100 per cent), but in healthy women too (97 per cent). The G. vaginalis concentration was significantly lower in the non-BV samples.

There were several G. vaginalis clades (offshoots, biologically speaking, like humans from apes) identified.

• Clade 1 – 53 per cent
• Clade 2 – 25 per cent
• Clade 3 – 32 per cent
• Clade 4 – 83 per cent

Multiple clades were found in 70 per cent of samples, with G. vaginalis clades (singles) represented by clade 1 and clade 4 in 28 per cent of the specimens. Clades 1 and 3 had a  positive association with BV, but clade 2 was positively associated with intermediate vaginal microflora – not BV. Clade 4 had no correlation.

If a woman had multiple clades, she had a higher risk of having BV, however if G. vaginalis was present in a single clade, it was not related to having BV.

Ultimately? Researchers found that ‘polyclonal G. vaginalis infection may be a risk factor for BV’.