Clinical evaluation of the Vitek automated system with cards GNS 122 and 127 and VTK-R07.01 software for antimicrobial susceptibility testing of Pseudomonas aeruginosa.

The performance of the Vitek Automated Susceptibility Testing System software version VTKR07.01 (bioMerieux Vitek, Hazelwood, MO), for testing Pseudomonas aeruginosa was evaluated by comparing results for 200 clinical isolates with those of disk diffusion and manual broth microtiter dilution testing. For cefepime, the restricted major error rate was 0.53% and the minor error rate was 12.5%. For piperacillin, the restricted major error rate was 2.15%. For ticarcillin/clavulanic acid, restricted very major and major error rates of 6.5% and 3.2%, respectively, occurred. The results of our study indicate that the Vitek system performs within acceptable limits when testing piperacillin, but remains problematic for testing cefepime and ticarcillin-clavulanic acid.