Abstract
Drug resistant Pseudomonas aeruginosa is responsible for severe nosocomial infections, and combination therapy is needed. We studied antibiotic combination effects by “break-point checkerboard Plate (BC plate)” and disk diffusion susceptibility test against drug resistant P. aeruginosa. Thirty-three strains of multi-drug resistant P. aeruginosa (MDRP) and metallo β lactamase (MBL) produced P. aeruginosa collected from February 2010 to June 2012 were tested using BC plate ‘eiken’ (Eiken Chemical Co. Ltd, Tokyo, Japan) to evaluate the effect with combined antibiotics. The isolates have combined effect rather than single drug effect were tested using KB disk (Eiken Chemical Co. Ltd, Tokyo, Japan). As a result, there were higher zone of inhibition against some isolates for AMK/AZT, CL/AZT, CL/RFP and RFP/AZT, and the other isolates were not strong zone (≤0.5 mm). Therefore, disk diffusion susceptibility test for MDRP and MBL produced P. aeruginosa is able to determine antibiotic combination effects when it is recognized apparent zone.
