Evaluation of Antibacterial Effects of Benzothiazole Derivatives on Bacterial Food Pathogens

Due to increasing of resistant to current antibiotic by bacterial pathogens, using of new antibacterial compound such as thiazole derivatives is necessary. In this test study we evaluate the inhibition effects of new thiazole derivatives on E. coli, S. typhimurium, B. cereus and L. monocytogenes. Synthesized thiazole derivatives were prepared in DMSO. Well method was used for the calculation of growth inhibition zone diameters and serial dilution method in microplates was utilized to assess minimum inhibitory concentrations (MICs). Inhibition effects were variable whit MIC 0-1000 µg/ml and inhibition zone 0-17.1 mm, so that, derivative 4 showed the best MIC on B. cereus andL. monocytogenes and derivative 6b showed the best MIC on L. monocytogenes. Thiazole derivatives showed significant inhibition effects on B. cereus and L. monocytogenes in comparison with E. coli and S. typhimurium. Only derivative 4 showed inhibition effects on gram-negative bacteria, also antibiogram tests showed higher resistant in E. coli and S. typhimurium. Our results show that benzo [d] thiazol derivatives have significant effective inhibition on bacterial pathogen especially on gram-positive bacteria, maybe existence of a thioamide chain bond to a thiazole ring has important role in antibacterial activity of these thiazole derivatives. In order to use new thiazole derivatives against food bacterial pathogens, they need more tests and in-vivo experiments.