Background: It is known that glycosidases and proteases are produced by the anaerobic gram-negative bacteria associated with bacterial vaginosis (BV). We hypothesized that these enzymes enzymatically degrade mucins, thereby destroying the mucus gel that otherwise helps protect against sexually transmitted pathogens, including HIV.
Goal: The goal was to determine glycosidase and protease production by vaginal bacteria associated with BV and to compare these with symptoms and signs of abnormal discharge and to test vaginal fluid viscosity.
Study design: The anaerobic gram-negative rods recovered from the vaginas of 153 women with normal flora, intermediate flora, or BV were tested for production of sialidase, fucosidase, galactosidase, glucosaminidase, and glycine and arginine aminopeptidases.
Results: Women with BV had higher frequencies and concentrations of bacteria producing mucin-degrading enzymes than did women with intermediate and normal flora (P < 0.001). Women with higher concentrations of bacteria producing mucin-degrading enzymes were more likely to have a thin discharge associated with BV (P < 0.001). The viscosity of diluted vaginal fluid samples from women with BV was significantly lower than those from women with normal flora (P = 0.001).
Conclusion: These data support the hypothesis that BV organisms degrade the protective mucus gel.