应用改良Hodge试验检测肠杆菌科细菌产碳青霉烯酶的研究

目的应用改良Hodge试验(MHT)检测肠杆菌科细菌产碳青霉烯酶的应用价值。方法应用MHT检测对碳青霉烯类抗菌药物敏感性降低的24株肠杆菌科细菌产碳青霉烯酶的情况。同时利用聚合酶链反应(PCR)检测碳青霉烯酶的基因,包括KPC、NDM、IMP、SIM和VIM,PCR阳性的产物测序结果与Gen Bank数据库进行比对。综合分析MHT和PCR检测碳青霉烯酶的效率。结果对碳青霉烯酶抗菌药物敏感性降低的24株肠杆菌科细菌应用MHT检测碳青霉烯酶的阳性菌株共为13株,而PCR检测出碳青霉烯酶基因的只有5株。且PCR产物测序结果经比对后证实1株为KPC-2和4株为IMP-4。对比分析MHT和PCR的检测结果可知有4株肠杆菌科细菌的MHT和PCR同时检测出碳青霉烯酶;有9株肠杆菌科细菌的MHT为阳性,但PCR没检测出碳青霉烯酶的基因;有1株肠杆菌科细菌MHT为阴性,但PCR检测出碳青霉烯酶的基因。结论 MHT作为筛查碳青霉烯酶肠杆菌科细菌的准确性值得继续探讨。

Research on screening carbapenemase-producing Enterobacteriaceae by modified Hodge test

Objective To discuss the application value of modified Hodge test(MHT) for screening carbapenemase-producing Enterobacteriaceae.Methods The 24 Enterobacteriaceae reduced susceptibility to carbapenems were detected by MHT.At the same time,polymerase chain reaction(PCR) was used to detect carbapenemase genes of KPC,NDM,IMP,SIM and VIM.PCR products were sequenced and the results were compared with the sequences of Gen Bank database.Comprehensive analysis the application value of MHT and PCR to detect carbapenemase.Results Among these 24 strains,13 stains appeared to produce carbapenemase by MHT,5 positive strains were found to carry carbapenemase genes by PCR.By comparing with the sequences of Gen Bank database 1 strain were confirmed to KPC-2 and 4 strains were confirmed to IMP-4.We found that 4 strains of Enterobacteriaceae,detected carbapenemase by MHT and PCR at the same time.9 strains of MHT were positive,but we couldn′t detect the carbapenemase genes.1 strain of MHT was negative,but carbapenemase gene was found in the strain.Conclusion The value of MHT to screen carbapenemase-producing Enterobacteriaceae is necessary to further study.