Evaluation of Antibacterial and Anticandidal Activities of Some Imidazole, Benzimidazole and Benztriazole Derivatives

In recent years, resistance to conventional antimicrobial drugs has become a serious concern in the clinic. Hence, the discovery of novel and effective antimicrobial agents with improved properties is of great value. In this study, the antibacterial and anticandidal activities of some imidazole, benzimidazole and benztriazole derivatives (C1-C8) against several species of Gram-positive and Gram-negative bacteria, including Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella typhi as well as one species of fungi including Candida albicans, were evaluated using Clinical Laboratory Standards Institute (CLSI) method. Antimicrobial evaluation revealed that among the tested compounds, imidazole derivative (C5) indicated the highest activity against bacterial strains and Candida albicans. It was found that compound C5 is more potent than ampicillin against S. aureus strain (MIC =2-16 μg/mL) and possessed excellent anticandidal activity (MIC =1 μg/mL) which was comparable to Amphotericin B as the positive control. In addition, cytotoxic activity of the tested compounds was investigated using MTT assay. The results of MTT assay demonstrated that the toxicity of the tested compounds was less than 35%.