Characterization of Staphylococci with Reduced Susceptibilities to Vancomycin and Other Glycopeptides
Characterization of Staphylococci with Reduced Susceptibilities to Vancomycin and Other Glycopeptides
复制标题
对万古霉素和其他糖肽敏感性降低的葡萄球菌的表征
DOI：
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发表时间：
1998
影响因子：
9.4
通讯作者：
K. Hiramatsu
中科院分区：
文献类型：
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作者：
F. Tenover;M. Lancaster;B. Hill;Christine D. Steward;S. Stocker;G. Hancock;C. O'hara;N. Clark;K. Hiramatsu
摘要 在过去的几年中，一系列葡萄球菌分离株被报道表明对万古霉素或其他糖肽的敏感性降低。我们选择了万古霉素 MIC ≥4 μg/ml 或替考拉宁 MIC ≥8 μg/ml 的 12 株葡萄球菌分离株和万古霉素 MIC ≤2 μg/ml 或替考拉宁 MIC ≤4 μg/ml 的 24 株对照菌株，以确定商业药敏试验程序和万古霉素琼脂筛选方法的能力。检测糖肽敏感性降低的分离株。通过PCR分析，糖肽敏感性降低的分离株均不含有已知的万古霉素抗性基因。肉汤微量稀释测试持续 24 小时最适合检测糖肽敏感性降低的菌株。纸片扩散没有将每毫升 8 μg 万古霉素抑制的菌株与更敏感的菌株区分开来。 MicroScan 常规板和 Etest 万古霉素试纸可识别大多数糖肽敏感性降低的分离株。尽管某些小组注意到这些分离株的 MIC 为 8 μg/ml，但视觉读取的 Sensititre 小组的可变性更大。对于万古霉素 MIC ≥ 4 μg/ml 的所有菌株，Vitek 结果均为 4 μg/ml。 Rapid MicroScan 面板上的万古霉素 MIC 无法预测，这些分离株的 MIC ≤2 或≥16 μg/ml。每毫升含有 6 μg 万古霉素的商业脑心输液万古霉素琼脂筛选板始终能够将 8 μg/ml 抑制的菌株与更敏感的菌株区分开来。内部制备的含万古霉素培养基偶尔会生长敏感菌株，即金黄色葡萄球菌 ATCC 29213，有时还会生长粪肠球菌 ATCC 29212。因此，对糖肽（如万古霉素）敏感性降低的葡萄球菌菌株最好在实验室中通过培养 24 小时的非自动定量测试进行检测。此外，商业万古霉素琼脂筛选板似乎可用于检测这些分离株。
ABSTRACT During the last several years a series of staphylococcal isolates that demonstrated reduced susceptibility to vancomycin or other glycopeptides have been reported. We selected 12 isolates of staphylococci for which the vancomycin MICs were ≥4 μg/ml or for which the teicoplanin MICs were ≥8 μg/ml and 24 control strains for which the vancomycin MICs were ≤2 μg/ml or for which the teicoplanin MICs were ≤4 μg/ml to determine the ability of commercial susceptibility testing procedures and vancomycin agar screening methods to detect isolates with reduced glycopeptide susceptibility. By PCR analysis, none of the isolates with decreased glycopeptide susceptibility contained known vancomycin resistance genes. Broth microdilution tests held a full 24 h were best at detecting strains with reduced glycopeptide susceptibility. Disk diffusion did not differentiate the strains inhibited by 8 μg of vancomycin per ml from more susceptible isolates. Most of the isolates with reduced glycopeptide susceptibility were recognized by MicroScan conventional panels and Etest vancomycin strips. Sensititre panels read visually were more variable, although with some of the panels MICs of 8 μg/ml were noted for these isolates. Vitek results were 4 μg/ml for all strains for which the vancomycin MICs were ≥4 μg/ml. Vancomycin MICs on Rapid MicroScan panels were not predictive, giving MICs of either ≤2 or ≥16 μg/ml for these isolates. Commercial brain heart infusion vancomycin agar screening plates containing 6 μg of vancomycin per ml consistently differentiated those strains inhibited by 8 μg/ml from more susceptible strains. Vancomycin-containing media prepared in-house showed occasional growth of susceptible strains, Staphylococcus aureus ATCC 29213, and on occasion, Enterococcus faecalis ATCC 29212. Thus, strains of staphylococci with reduced susceptibility to glycopeptides, such as vancomycin, are best detected in the laboratory by nonautomated quantitative tests incubated for a full 24 h. Furthermore, it appears that commercial vancomycin agar screening plates can be used to detect these isolates.