Oleate lipase activity in Gardnerella vaginalis and reconsideration of existing biotype schemes

Background  

Gardnerella vaginalis is a facultative gram positive organism that requires subculture every 1–2 days to maintain viability. It has been linked with bacterial vaginosis (BV), a syndrome that has been associated with increased risk for preterm delivery, pelvic inflammatory disease and HIV acquisition. About 10% of the G. vaginalis isolates have been reported to produce sialidase, but there have not been any studies relating sialidase production and biotype. Sialidase activity is dramatically increased in the vaginal fluid of women with BV and bacterial sialidases have been shown to increase the infectivity of HIV in vitro. There are 8 different biotypes of G. vaginalis. Biotypes 1–4 produce lipase and were reported to be associated with BV and the association of these biotypes with BV is under dispute. Other studies have demonstrated that G. vaginalis biotype 1 can stimulate HIV-1 production. Because of the discrepancies in the literature we compared the methods used to biotype G. vaginalis and investigated the relationship of biotype and sialidase production.