In-use evaluation of a prediluted quantitative antibiotic susceptibility test device.

An antibiotic susceptibility test (AST) device is described. Minimum inhibitory concentration results on 1,294 clinical isolates with seven antibiotics were rapid, reliable, and reproducible. Agreement with the disk diffusion test was 90%. Interlaboratory agreement for the AST was 94%. The AST provides minimum inhibitory concentration capability without the necessity of prior weighing and dilution of antibiotics.