Protection of mice from a Chlamydia trachomatis vaginal infection using a Salicylidene acylhydrazide, a potential microbicide.

The salicylidene acylhydrazide INP0341 inhibits growth of Chlamydia in HeLa cells, has negligible cell toxicity, and does not inhibit the growth of lactobacilli. The antichlamydial activity of INP0341 was retained when tested in vaginal and semen simulants. Vaginal tissue from INP0341-treated mice appeared similar to control sham-treated mice. To determine whether INP0341 can protect mice from a vaginal challenge, C3H/HeJ mice were either sham or INP0341 treated intravaginally pre- and postinoculation with 5 × 10(2) inclusion-forming units (IFUs) of Chlamydia trachomatis serovar D. Vaginal cultures taken over a month-long period showed a significant difference in the number of control mice that were culture positive versus the number in the INP0341-treated group, 100% (25/25) and 31% (8/26), respectively (P < .05). The quantity of IFUs shed and antibody titers to Chlamydia were significantly higher for the control group (P < .05). In summary, INP0341 is a promising compound to be considered for formulation as a vaginal microbicide.