Susceptibility testing of carumonam: interpretive criteria for 30-microgram disk tests and quality control guidelines for disk diffusion and broth microdilution methods.

Carumonam 30-microgram disk diffusion tests with 342 gram-negative organisms suggested modifying earlier interpretive zone criteria, i.e., a susceptibility zone diameter of greater than or equal to 23 mm (less than or equal to 8.0 micrograms/ml MIC correlate) and a resistance zone diameter of less than or equal to 17 mm (greater than or equal to 32 micrograms/ml MIC correlate). Quality assurance guidelines were determined by multilaboratory investigations. Recommended limits were calculated for the gram-negative quality control organisms only. For Escherichia coli ATCC 25922, the recommended limits are 30 to 36 mm and 0.03 to 0.25 micrograms/ml, and for Pseudomonas aeruginosa ATCC 27853, they are 24 to 32 mm and 1.0 to 4.0 micrograms/ml.