Susceptibility of 461 Nosocomial Gram-Negative Pathogens to Enoxacin and Other Antibiotics

The in vitro activity of enoxacin against 461 strains of Gram-negative aerobic bacteria, recently isolated from clinical specimens, was assessed by broth dilution techniques which determined minimum inhibitory concentrations (MICs). The sensitivity of all species of Gram-negative fermentative bacteria ranged from 66.6% (Kluyvera ascorbata and Morganella morganii) to 100% (Hafnia alvei) [MIC range 0.25 to 64 mg/L]. For Gram-negative nonfermentative species, the overall susceptibility of isolates ranged from 53% for Pseudomonas aeruginosa to 100% for Alcaligenes faecalis and Aeromonas hydrophila. The percentages of resistant strains to enoxacin were evaluated in comparison with piperacillin, ceftazidime, gentamicin, netilmicin and amoxicillin using a standard agar diffusion technique. Although enoxacin demonstrated some interspecies variability, in actuality it showed similar overall activity to that of ceftazidime, gentamicin and netilmicin, but was more active overall than piperacillin and amoxicillin.