Activity of ciprofloxacin against multiply resistant strains of Pseudomonas aeruginosa, Staphylococcus epidermidis, and group JK corynebacteria.

The susceptibilities of multiply resistant clinical isolates of Pseudomonas aeurginosa to ciprofloxacin, norfloxacin, and several beta-lactam and aminoglycoside antibiotics were evaluated. Ciprofloxacin also was compared with methicillin and vancomycin against methicillin-resistant Staphylococcus epidermidis and group JK corynebacteria. Ciprofloxacin exhibited the lowest MICs and MBCs for 90% of the isolates among all of the antibiotics tested against P. aeruginosa. In addition, ciprofloxacin exhibited excellent bactericidal activity against the gram-positive organisms. Clinical trials are necessary to confirm the in vitro results and monitor for emergence of resistance.