A novel bacterial mucinase, glycosulfatase, is associated with bacterial vaginosis

The modifications to the vaginal habitat accompanying a change to vaginal flora in bacterial vaginosis (BV) are poorly understood. In this study enzymes involved in mucin degradation were measured, including a novel glycosulfatase assay. Women attending an emergency walk-in sexually transmitted disease clinic were studied. One high vaginal swab (HVS) was used to prepare a gram-stained smear to determine BV status, using Ison and Hay's criteria, and a separate swab was used for the purposes of the assays. The median glycosulfatase activity was 8.5 (range, -1.2 to 31.9) nmol h(-1) 1.5 ml(-1) of HVS suspension in patients with BV compared to 0.5 (range, -0.7 to 9.4) nmol h(-1) 1.5 ml(-1) of HVS suspension in patients without BV (P = <0.001). The median glycoprotein sialidase activity was 29.2 (range, -17 to 190) nmol h(-1) 1.5 ml(-1) of HVS suspension in patients with BV compared to -1.1 (range, -41 to 48) nmol h(-1) 1.5 ml(-1) of HVS suspension in patients without BV (P < 0.001). A rapid spot test for sialidase was positive in 22/24 patients with BV (sensitivity, 91.7%; 95% confidence interval [CI], 73 to 99%) and negative in 32/35 patients without BV (specificity, 91.4%; 95% CI, 76.9 to 98.2%) (P < 0.001). Glycosulfatase activity significantly correlated with both glycoprotein sialidase activity and the sialidase spot test (P = 0.006 and P < 0.001, respectively). The results are consistent with the hypothesis that the consortium of bacteria present in BV requires the ability to break down mucins in order to colonize the vagina and replace the normal lactobacilli.