MICROBICIDAL AGENT C31G INHIBITS CHLAMYDIA-TRACHOMATIS INFECTIVITY IN-VITRO

Safe and effective vaginal microbicidal compounds are being sought to offer women an independent method for protection against transmission of sexually acquired pathogens, The purpose of this study was to exami ne the efficacy of two formulations of one such compound, C31G, agains t Chlamydia trachomatis serovar E alone, its host epithelial cell (HEC -1B) alone, and against chlamydiae-infected HEC-1B cells, Preexposure of isolated, purified infectious chlamydial elementary bodies (EB) to C31G, at pHs 7.2 and 5.7, for 1 h at 4 degrees C resulted in reduced i nfectivity of EB for HEC-1B cells, Examination of the C31G-exposed S-3 5-EB on sodium dodecyl sulfate-polyacrylamide gel electrophoresis auto radiographs and by Western blotting revealed a C31G concentration-depe ndent and pa-dependent destabilization of the chlamydial envelope, res ulting in the release of chlamydial lipopolysaccharide and proteins, I nterestingly, when the host human genital columnar epithelial cells we re infected with chlamydiae and then exposed to dilute concentrations of C31G which did not alter epithelial cell viability, chlamydial infe ctivity was also markedly reduced, C31G gained access to the developin g chlamydial inclusion causing damage to or destruction of metabolical ly active reticulate bodies as well as apparent alteration of the incl usion membrane, which resulted in premature escape of chlamydial antig en to the infected epithelial surface. These studies show that the bro ad-spectrum antiviral and antibacterial microbicide C31G also has anti chlamydial activity.