In vitro susceptibility of Gardnerella vaginalis and Bacteroides organisms, associated with nonspecific vaginitis, to sulfonamide preparations.

Recent reports suggest that anaerobic Bacteroides organisms are frequently found with Gardnerella vaginalis in nonspecific vaginitis. Specimens taken from 96 women with vaginal discharge were tested simultaneously for these organisms. G. vaginalis was found in 73% of the specimens, Bacteroides was found in 53%, and both organisms were found in 47%. Sulfonamides have been widely used in the successful treatment of vaginitis. Paradoxically, G. vaginalis is reported to be resistant, and it has been suggested that it could be the vehicle of the drugs which effects the cure. Little is known of the susceptibility of vaginal anaerobes to the sulfonamides. G. vaginalis and Bacteroides isolates were therefore tested in vitro against the individual excipients of sulfonamide tablets, and minimal inhibitory concentration tests were also performed against the three active drugs. The excipients had no effect on G. vaginalis, but Bacteroides strains were susceptible to the urea component. All strains of both organisms were susceptible to at least two of the three sulfonamides at high concentrations.