Potential antimicrobial activity of new metronidazole derivatives against pathogenic clinical isolates

The present study aims to investigate potential antimicrobial activity of new metronidazole derivatives against clinical isolates of Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Candida albicans. A total of six different concentrations ( 6.25-200 mu g/ml) of two newly synthesized metronidazole derivatives (MTD1 and MTD2) were tested by disc diffusion method of Kirby-Bauer on Mueller-Hinton agar. The selection of solvents was very precisely according to solubility of new compounds. Therefore, we have used the following solvents: NaCl 0.9%, Phosphate buffer pH 7.2, methanol and ethanol. The methanol and ethanol solutions of metronidazole derivatives showed antimicrobial activity against S. aureus and C. albicans. Derivatives MTD1 and MTD2 (concentrations 100 mu g / ml and more) demonstrated inhibition zones of 12-14 mm, both against S. aur derivatives-Ethyl 4-(2-(2-methyl-5-nitro-1H- imidazol-1-yl) acetamide) benzoate (MTD1) and Butyl 4-(2-(2-methyl-5-nitro-1H-imidazol-1- yl) acetamide) benzoate (MTD2)eus and against Candida. For each sample in NaCl 0,9% and Phosphate buffer there was not detected antimicrobial activity more than the controls. The tested derivatives did not show antibacterial activity against E.coli and B. subtilis strains.