IN-VITRO POSTANTIBIOTIC EFFECT OF IMIPENEM AND ENOXACIN ALONE IN COMBINATION AGAINST PSEUDOMONAS-AERUGINOSA

The postantibiotic effects (PAEs), i.e. suppression of growth of three Pseudomonas aeruginosa strains (386, 648, 659) after a short treatmen t (30 min) with imipenem and enoxacin alone and in combination were ev aluated. Imipenem (2 x MIC) induced PAEs for two strains or 0.5 h (384 , 648) at concentrations of 4 x MIC, PAEs lasted 0.8 h (386), 2 h (648 ) and 1.5 h (659). The PAE values of enoxacin (2 x MIC) were 4.6 h (38 6), 1.7 h (648), 1.6 h (659) and those of enoxacin (4 X MIC) were 6.1 h (386), 3.2 h (648) and 2.1 h (659), PAEs manifested by an imipenem/e noxacin combination were longer than the mathematical sum of PAEs indu ced by individual antibiotics. Prolongation of PAEs induced by the imi penem (2 x MIC)/enoxacin (2 x MIC) combination was 25.5% and 27.3% (st rains 386 and 648) as well as 27.8%, 32.4% and 16.1% (stains 386, 648 and 659) after treatment with imipenem (4 x MIC)/enoxacin (2 x MIC).