Washington J A, Yu P K, Gavan T L, Schoenknecht F D, Thornsberry C
Antimicrob Agents Chemother. 1979 Mar;15(3):400-7. doi: 10.1128/AAC.15.3.400.
Because excessively high rates of false resistance have been encountered with the 10-mug amikacin disk in diffusion susceptibility tests, a study was performed to examine existing zone diameter interpretative criteria and to compare the accuracy of 10- and 30-mug amikacin disks by the error rate-bounded classification scheme. Although current zone diameter interpretative criteria eliminate false susceptibles, there is an unacceptably high rate of false resistants. This problem can be resolved in most instances by revising the zone diameter interpretative criteria for the 10-mug disk (resistant, </=9 mm; indeterminate, 10 to 11 mm; susceptible, >/=12 mm) or, preferably, by replacing the 10-mug disk with a 30-mug disk and adopting new interpretative criteria (resistant, </=14 mm; indeterminate, 15 to 16 mm; susceptible, >/=17 mm). Because of significant differences in performance among media, it is necessary to include Pseudomonas aeruginosa ATCC 27853 among controls routinely tested and to exclude from use lots of Mueller-Hinton agar yielding results outside the 75% tolerance (90% confidence) limits for amikacin.
由于在扩散药敏试验中使用10μg阿米卡星纸片时遇到过高的假耐药率，因此开展了一项研究，以检查现有的抑菌圈直径解释标准，并通过误差率限定分类方案比较10μg和30μg阿米卡星纸片的准确性。尽管当前的抑菌圈直径解释标准消除了假敏感，但假耐药率高得令人无法接受。在大多数情况下，这个问题可以通过修订10μg纸片的抑菌圈直径解释标准（耐药，≤9mm；不确定，10至11mm；敏感，≥12mm）来解决，或者更好的方法是用30μg纸片取代10μg纸片并采用新的解释标准（耐药，≤14mm；不确定，15至16mm；敏感，≥17mm）。由于不同培养基之间的性能存在显著差异，有必要将铜绿假单胞菌ATCC 27853纳入常规测试的对照菌株中，并排除使用那些对阿米卡星产生的结果超出75%耐受范围（90%置信区间）的穆勒-欣顿琼脂批次。
