Antimicrobial susceptibility of comma-shaped bacteria isolated from the vagina.

Comma-shaped bacteria isolated from the posterior vaginal fornix of women with foul-smelling discharge were tested for their antimicrobial susceptibility. The 20 strains studied were tested anaerobically, using agar dilution tests. They were highly susceptible to beta lactam antibiotics, clindamycin, doxycycline, erythromycin, gentamicin and thiamphenicol. On the other hand, the bacteria were relatively resistant to sulfamethoxazole, nalidixic acid and nitroimidazoles. A difference in susceptibility to nitroimidazoles between long and short variants of the comma-shaped bacteria was found; the former being more susceptible than the latter.