Potentiality of tricyclic compound thioridazine as an effective antibacterial and antiplasmid agent

Abstract

Thioridazine (Th), which is therapeutically used in psychiatric patients, was found to possess conspi-cuous antimicrobial activity when tested against 316 strains belonging to a number of Gram positive and Gram negative bacteria. Although <i>Staphylococcus aureus, Vibrio cholerae </i>and <i>V. parahaemolyticus </i>were found to be most sensitive, Th was highly bactericidal against <i>S aureus </i>and bacteriostatic for vibrios and other Gram negative organisms. In the study of antiplasmid/curing effect of Th on twelve multiply antibiotic and Th resistant bacteria, it was observed that elimination of R plasmids was facilitated by

choice of optimal concentration of Th. Significant elimination of single and combined antibiotic resistances occurred in <i>E. coli </i>and <i>Shigella flexneri </i>and not in <i>S.aureus.</i>