In Vitro Activities of Quinolones and Vancomycin Against Methicillin-and Gentamicin-Resistant Staphylococcus aureus

Authors: 0sman ERKMEN, Sabri GÜNGÖR

Abstract: Nineteen methicillin and gentamicin-resistant S. aureus (MGRSA) were isolated from wounds, sputum and catheter sites of admitted patients in Gaziantep University Hospital. The antistaphylococcal acti vities of ciprofloxacin, enoxacin, norfloxacin, pefloxacin, oflaxacin and vancomycin were evaluated by in vitro studies. Antibiotic concentrations with 0,1 and 4 times the MIC values were used against sixteen quinolone sensitive MGRSA strains in time-kill kinetic studies. MIC and MBC values of the antibiotics were indicated by using tube dilution method. Phage-types of strains were also determined. The MIC values which could kill 90 % of the strains (MlC90) were 1.56 µg/mL for ciprofloxacin and enoxacin, 3.12 µg/mL for norfloxacin, ofloxocin, pefloxacin and vancomycin. The MIC values of ciprofloxacin, enoxacin and norfloxacin showed a marked reduction effects after 8 h incubation. The MIC values at 4 time dilution showed bactericidal activity in 8 h. Ciprofloxacin, enoxacin and norfloxacin showed greater activity comparable to vancomycin against MGRSA.

Keywords: Methicillin-Resistan S. aureus; Gentamicin-and Metchicillin-Resistant S. aureus; Quinolones.