In vitro activities of 2,2′-dipyridyl against Trichomonas vaginalis, Candida albicans, and Gardnerella vaginalis

The in vitro activity of 2,2'-dipyridyl, an iron-chelator, against clinical isolates of Trichomonas vaginalis. Candida albicans, and Gardnerella vaginalis was evaluated and compared with those of four other vaginal suppositories. ornidazole, clotrimazole, povidone-iodine. and Cenacert(R) (Methylbenzethonium Chloride mixed with 9-aminoacrydine undecylenate and hydrochloric acid N-myristyl-3-hydroxy butyl amine). The 2.2'-dipyridyl killed T. vaginalis and G. vaginalis at concentrations of 410 mug/ml and 205 mug/ml, respectively, however, this agent was less active against C. albicans (80% of which was inhibited at 410 mug/ml). The inhibition of these three pathogens by 2,2'-dipyridyl was similar to clotrimazole. In addition, the effect of 2,2'-dipyridyl on the ultrastructure of T. vaginalis. C, albicans, and G. vaginalis was examined. Transmission electron microscopy indicated that 2,2'-dipyridyl induced modifications of the cellular contents and cell envelope concomitant with the degradation of the three pathogens. These results suggest that 2.2'-dipyridyl has an inhibitory effect on C. albicans and G. vaginalis, as well as T. vaginalis.