QUALITY-CONTROL GUIDELINES FOR AMOXICILLIN, AMOXICILLIN-CLAVULANATE, AZITHROMYCIN, PIPERACILLIN-TAZOBACTAM, ROXITHROMYCIN, TICARCILLIN, TICARCILLIN-CLAVULANATE, TROVAFLOXACIN (CP-99,219), U-100592, AND U-100766 FOR VARIOUS TIONAL-COMMITTEE-FOR-CLINICAL-LABORATORY-STANDARDS SUSCEPTIBILITY TESTING METHODS - RESULTS FROM MULTICENTER TRIALS

Quality control guidelines for standardized antimicrobial susceptibili ty test methods are critical to the continuing accuracy of the tests. In this report, quality control limits were proposed for 22 organism-a ntimicrobial combinations with minimum inhibitory concentration (MIC) ranges of three or four log(2) dilution steps. Disk diffusion zone dia meter ranges were proposed for azithromycin compared with Neisseria go norrhoeae ATCC 49226 and ticarcillin with and without clavulanic acid tested against Staphylococcus aureus ATCC 25923. The data from five or six participating laboratories produced greater than or equal to 94.7 % of results within proposed MIC limits, and 94.3%-99.0% of zones were found within suggested zone guidelines. These proposed quality contro l ranges should be validated try in-use results from clinical laborato ries.