Rapid antimicrobial susceptibility testing of Gram-negative clinical isolates with the AutoMicrobic system

Comparisons of the antimicrobial susceptibility patterns of clinical isolates of the family Enterobacteriaceae and Pseudomonas aeruginosa were made by using Kirby-Bauer disk diffusion, the MicroMedia system broth microdilution, and the AutoMicrobic system. The Kirby-Bauer system compared favorably with the MicroMedia system (95% essential correlation with 90% complete agreement). The AutoMicrobic system also compared favorably with both the Kirby-Bauer system (93% essential correlation with 87% complete agreement) and the MicroMedia system (97% essential correlation with 85% complete agreement). These data indicate that the AutoMicrobic system results are comparable to those of the MicroMedia and the Kirby-Bauer systems. Furthermore, the AutoMicrobic system offers a more rapid system (6 to 10 h), than the traditional systems, without sacrificing accuracy (16 to 24 h).