Comparative in vitro Activity of Some Macrolide (Erythromycin, Clarithromycin and Azithromycin) and Fluoroquinolone (Ciprofloxacin and Ofloxacin) Antibiotics Against Bacillus anthracis

摘要

In vitro activity of three members of the macrolide group of antibiotics (Erythromycin, Clarithromycin and Azithromycin) and two members of the fluoroquinolone group of antibiotics (Ciprofloxacin and Ofloxacin) were assessed against Bacillus anthracis by standard tube dilution method. All the isolates showed varied susceptibility to the 2 groups of antimicrobial agents. The isolates were susceptible to Ciprofloxacin (MIC50-0.78 μg mL 1) and Ofloxacin (MIC50-0.31 μg mL 1) but were resistant to Erythromycin ((MIC50-25 μg mL 1), Clarithromycin ((MIC50-31.25 μg mL 1) and Azithromycin ((MIC50-200 μg mL 1). Comparing the results of the 2 groups of antibiotic susceptibility tests, we do not recommend the use of any of the 3 macrolide antibiotics tested for prophylaxis or therapy of B. anthracis in our geographical area, except with specific result of susceptibility test on the particular isolate(s). Ofloxacin is highly recommended as a good alternative to ciprofloxacin antibiotic.