Comparison of in vitro activity of gatifloxacin and other four fluoquinolones against clinical isolates

AIM: To compare in vitro activity of gatifloxacin against 182 clinical isolated pathogens with those of ciprofloxacin, ofloxacin, levofloxacin and sparfloxacin. METHODS: The MICs of 182 clinical isolated pathogens were determined by the two fold agar dilution method. RESULTS: The MIC 90 of gatifloxacin against staphylococcus species was lower than the other four fluoquinolones. The ratio of sensitivity of staphylococcus species to gatifloxacin was higher than the other four fluoquinolones; the MIC R of gatifloxacin against other gram positive cocci was lower than the other four fluoquinolones. The ratios of sensitivity of gram negative bacilli, such as Escherichia species and Enterobacter species to gatifloxacin were higher than the other four fluoquinolones; The MIC 90 of gatifloxacin against escherichia species and enterobacter species was 2 fold lower than levofloxacin and 8 fold lower than the other 3 fluoquinolones. The ratios of sensitivity of pseudomonas species, klebsiella species and other gram negative bacilli to gatifloxacin had no significance with levofloxacin and were higher than ciprofloxacin, ofloxacin, and sparfloxacin. CONCLUSION: In vitro activity of gatifloxacin against common clinical bacterium is strong.