Minshew B H, Pollock H M, Schoenknecht F D, Sherris J C
Antimicrob Agents Chemother. 1977 Dec;12(6):688-96. doi: 10.1128/AAC.12.6.688.
From July 1974 through June 1976, a number of isolates of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa from the Burn Center exhibited a shift to smaller zone diameters with gentamicin than did isolates from the general hospital population. Although many had zone diameters >/=13 mm and would have been considered susceptible by this breakpoint, they were found to have minimal inhibitory concentrations (MICs) of >/=8 mug of gentamicin per ml by agar dilution testing. Zone diameters and MICs of gentamicin, tobramycin, and amikacin were subsequently compared for 168 isolates from both the Burn Center and general hospital. The results revealed many isolates that fell into presently used gentamicin- and tobramycin-"susceptible" categories by disk diffusion tests but were resistant by MIC. The data indicated that criteria for gentamicin disk diffusion testing should include an intermediate or indeterminate category, and that the limits of the intermediate category for tobramycin and amikacin should be expanded.
从1974年7月至1976年6月，烧伤中心分离出的一些大肠杆菌、肺炎克雷伯菌和铜绿假单胞菌与综合医院人群分离出的菌株相比，对庆大霉素的抑菌圈直径变小。尽管许多菌株的抑菌圈直径≥13毫米，根据这个断点本应被视为敏感，但通过琼脂稀释试验发现它们的最低抑菌浓度（MIC）≥8微克/毫升庆大霉素。随后对烧伤中心和综合医院的168株分离菌的庆大霉素、妥布霉素和阿米卡星的抑菌圈直径和MIC进行了比较。结果显示，许多菌株通过纸片扩散试验属于目前使用的庆大霉素和妥布霉素“敏感”类别，但通过MIC检测为耐药。数据表明，庆大霉素纸片扩散试验的标准应包括一个中介或不确定类别，并且妥布霉素和阿米卡星中介类别的界限应扩大。
