Detection of Pseudomonas aeruginosa producing metallo-β-lactamases in a large centralized laboratory
Detection of Pseudomonas aeruginosa producing metallo-β-lactamases in a large centralized laboratory
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DOI：
10.1128/jcm.43.7.3129-3135.2005
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发表时间：
2005-07-01
影响因子：
9.4
通讯作者：
Church, DL
中科院分区：
文献类型：
--
作者：
Pitout, JDD;Gregson, DB;Church, DL
金属β-内酰胺酶（MBL）已越来越多地从世界各地的临床分离株中被认识到，但这些菌株的实验室检测并没有很好地定义。我们报告了一项研究，开发了一种EDTA纸片筛选试验和一种分子诊断试验来检测产生MBL的铜绿假单胞菌。使用NCCLS盘法，在单独使用亚胺培南（IPM）和美罗培南（MEM）盘以及与930 μ g EDTA组合的测试中测定抑制区直径。将该测试与MBL Etest进行比较。双重PCR检测显示100%的灵敏度和特异性检测MBL生产的对照菌株。在2002年至2004年从卡尔加里卫生区分离的241株IPM不敏感铜绿假单胞菌临床菌株中，110/241（46%）使用表型方法为MBL阳性，而107/241（45%）为MBL基因PCR阳性：103/241（43%）为bla（Vim），4/241（2%）为bla（IMP）。使用MEM的EDTA纸片筛选试验显示，检测对照和临床菌株中MBL的灵敏度为100%，特异性为97%。EDTA纸片筛选试验易于执行和解释，可以很容易地引入临床实验室的工作流程。我们建议使用EDTA纸片筛选试验对所有IPM不敏感的铜绿假单胞菌分离株进行MBL生产的常规筛选，并在区域实验室进行PCR确认。
Metallo-beta-lactamases (MBLs) have been increasingly recognized from clinical isolates worldwide, but the laboratory detection of these strains is not well defined. We report a study that developed an EDTA disk screen test and a molecular diagnostic assay for the detection of MBL-producing Pseudomonas aeruginosa. Using NCCLS disk methodology, inhibition zone diameters were determined in tests with imipenem (IPM) and meropenem (MEM) disks alone and in combination with 930 mu g of EDTA. This test was compared with the MBL Etest. The duplex PCR assay showed 100% sensitivity and specificity for detecting MBL-producing control strains. Of the 241 clinical strains of IPM-nonsusceptible P. aeruginosa from the Calgary Health Region isolated from 2002 to 2004, 110/241 (46%) were MBL positive using phenotypic methods while 107/241 (45%) were PCR positive for MBL genes: 103/241 (43%) for bla(VIM) and 4/241 (2%) for bla(IMP). The EDTA disk screen test using MEM showed 100% sensitivity and 97% specificity for detecting MBLs in control and clinical strains. The EDTA disk screen test is simple to perform and to interpret and can easily be introduced into the workflow of a clinical laboratory. We recommend that all IPM-nonsusceptible P. aeruginosa isolates be routinely screened for MBL production using the EDTA disk screen test and that PCR confirmation be performed at a regional laboratory.