Introduction Bacterial vaginosis (BV) is the most common vaginal infection among women around the world, characterised by the replacement of the normal vaginal microbiota by anaerobic bacteria, mainly G. vaginalis a Gram negative coccobacillus that is isolated in up to 98% of the cases. This bacterium is classified into eight biotypes and has several virulence factors such as the production of biofilm and phospholipase C (PLC) that are associated with gineco-obstetric complications. Therefore, it is necessary to evaluate the relationship between biotypes and virulence factors with BV, which was the main objective of this study.

Methods 250 samples of vaginal swab were analysed; the samples were inoculated on Columbia agar for the isolation of G. vaginalis. We use Amsel and Nugent criteria for the classification of vaginal flora and for the diagnosis of BV. For biotyping, we use Piot et al 1984 classification (hydrolysis of hippurate, β-galactosidase and lipase). Biofilm production was performed in 96-well plates and the results were classified as non-producing (<0.1), moderate (0.1–0.2) and abundant (>0.2). We measured PLC production on skim milk agar.

Results We isolated G. vaginalis in 75% (187) of the samples, of wich 15% (37) were associated with BV whereas 60% (150) with normal flora. We identify biotypes 1 (19%), 2 (8%), 5 (16%) and 6 (57%) in BV cases, whereas in normal flora we identify the same biotypes at different frequency [1 (22%), 2 (11%), 5 (21%) and 6 (46%)]. We observed PLC production in 22% of the cases associated with BV and at 27% in normal flora. We observed that 76% of strains associated with BV were non-producers, 19% were moderate and 5% were abundant, whereas in the normal flora group was 66%, 26% and 8%, respectively.

Conclusion: G. vaginalis was isolated in 75% of the samples (15% associated with BV and 60% in normal flora). We identified biotypes 1, 2, 5 and 6 of G. vaginalis; the production of PLC and biofilm was similar in both study groups. We couldn’t associate biotypes and virulence factors with BV.