应用EDTA协同法检测肠杆菌科细菌产金属β-内酰胺酶的研究

摘要

Objective To discuss the accuracy of EDTA-disk synergy test for screening MBL-producing Enterobacteriaceae, and to provide a simple method for clinical quick screening MBL-producing Enterobacteriaceae. Methods The mctallo-beta-lactamascs of 27 Enterobacteriaceae with reduced susceptibility to carbapenems were detected by EDTA-disk synergy test in the M-H agar plates. The enzyme inhibitor was EDTA ? Na2 , and the substrate was meropencm. At the same time,polymcrasc chain reaction (PCR) was used to detect MBL genes of NDM-1 , IMP, VIM and SIM. PCR products were sequenced and the results were compared with the sequences of GenBank database. Results Of these 27 strains,4 appeared to produce MBL by EDTA-disk synergy test,which was consistant with the results of PCR. The 4 positive strains were found to carry genes for IMP-4 type MBL(blaIMP-1 )by DNA sequencing. Conclusion EDTA-disk synergy test detecting mctallo-beta-lactamasc-producing Enterobacteriaceae is a simple and credible method. It is suitable for quick screening MBL-producing Enterobacteriaceae in clinical microbiology laboratory.%目的 探讨应用EDTA协同法检测肠杆菌科细菌产金属β-内酰胺酶(MBL)的准确性,为临床快速筛查产MBL的肠杆菌科细菌提供简便的方法.方法 对碳青霉烯类抗生素敏感性降低的27株肠杆菌科细菌在M-H琼脂平板上用双纸片协同法检测其MBL,以EDTA·Na2为酶抑制剂,美罗培南为底物.同时利用聚合酶链反应(PCR)检测MBL的基因NDM-1A、NDM-1B、IMP、VIM和SIM,PCR扩增阳性的产物测序结果与GenBank数据库进行比对分析.结果 对碳青霉烯类抗生素敏感性降低的27株肠杆菌科细菌运用EDTA协同法检测MBL的阳性菌株为4株,与PCR检测MBL结果一致.且PCR产物测序结果经比对分析后证实均为IMP-4型MBL.结论 EDTA协同法检测肠杆菌科细菌产MBL方法简便、结果可靠,适用于临床对碳青霉烯类抗生素敏感性降低的肠杆菌科细菌产MBL的快速筛查.