A multicenter study evaluating the current strategies for isolating Staphylococcus aureus strains with reduced susceptibility to glycopeptides
A multicenter study evaluating the current strategies for isolating Staphylococcus aureus strains with reduced susceptibility to glycopeptides
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DOI：
10.1128/jcm.01508-06
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发表时间：
2007-02-01
影响因子：
9.4
通讯作者：
Howe, Robin A.
中科院分区：
文献类型：
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作者：
Wootton, Mandy;MacGowan, Alasdair P.;Howe, Robin A.
众所周知，糖肽中间型金黄色葡萄球菌（GISA）和异质性GISA（hGISA）菌株在诊断实验室中难以检测。GISA，特别是hGISA的临床重要性，只有在确定的检测方法可用时才是显而易见的。已经提出了一些新的GISA和hGISA检测方法;然而，它们的有效性从未在不同的实验室进行过大规模的测试。本研究比较了12个实验室检测GISA和hGISA菌株的三种筛选方法，使用已知糖肽亲和性的48株菌株的盲板。使用的三种筛选方法为含6 mg/L万古霉素的脑心浸液琼脂（BHIA 6V）（CDC/CLSI）、含5 mg/L替考拉宁的Mueller-Hinton琼脂（MHA 5 T）（欧洲抗菌药物耐药性监测系统[EARSS]）和大量稀释法Etest（MET）（EARSS），以群体分析曲线-曲线下面积分析作为金标准。MHA 5 T和MET的敏感性和特异性最高，分别识别82.5%和85.9%的菌株。BHIA 6V的敏感性较差，特别是对hGISA（检出11.5%的菌株），并且在性能上具有最大的实验室间差异。MET表现出最小的实验室间变异。实验室必须使用适当的方法检测GISA/ hGISA菌株，以便正确评估这些菌株的流行率和临床重要性。
Glycopeptide-intermediate Staphylococcus aureus (GISA) and heterogeneous GISA (hGISA) strains are notoriously difficult to detect in the diagnostic laboratory. The clinical importance of GISA, and particularly hGISA, will only be obvious when a definitive detection method is available. A few novel GISA and hGISA detection methods have been proposed; however, their validity has never been tested on a significant scale and in different laboratories. This study compares three screening methods for detecting GISA and hGISA strains in 12 laboratories, using a blind panel of 48 strains with known glycopeptide susceptibilities. The three screening methods used were brain heart infusion agar with 6 mg/liter vancomycin (BHIA6V) (CDC/CLSI), Mueller-Hinton agar with 5 mg/liter teicoplanin (MHA5T) (European Antimicrobial Resistance Surveillance System [EARSS]), and the macrodilution method Etest (MET) (EARSS), with population analysis profile-area under the curve analysis as the gold standard. Sensitivity and specificity were highest for MHA5T and MET, which identified 82.5% and 85.9% of strains, respectively. BHIA6V had poor sensitivity, particularly for hGISA (11.5% of strains were detected), and gave the largest interlaboratory variation in performance. MET exhibited the least interlaboratory variation. It is essential that laboratories use appropriate methods to detect GISA/ hGISA strains so that the prevalence and clinical importance of these strains can be assessed properly.