NG-Test CARBA 5在血培养肠杆菌科细菌碳青霉烯酶检测中的优势及其检测效能

Advantages and efficacy of NG-Test CARBA 5 in the detection of carbapenemase in blood cultured enterobacteriaceae bacteria

目的探讨NG-Test CARBA 5在血培养肠杆菌科细菌碳青霉烯酶含量检测的应用价值。方法收集我院临床标本中分离培养的已知基因型别的62株肠杆菌目细菌,包含耐碳青霉烯肠杆菌科细菌38株和对碳青霉烯敏感的肠杆菌科细菌24株,分别采用NG-Test CARBA 5试剂盒、Carba NP和mCIM试验检测待测菌株的主要碳青霉烯酶,并采用PCR法对碳青霉烯酶基因表型进行测序确认和Kappa一致性检验;再从38株耐碳青霉烯菌株中随机取出20株菌株进行模拟血培养,并对其进行NG-Test CARBA 5试剂盒、Carba NP法和mCIM法检测和Kappa一致性检验分析。结果38株耐碳青霉烯肠杆菌科细菌菌株的耐药药物均为美罗培南和/或亚胺培南,PCR扩增测序结果表明,分别有33株菌株携带有耐药基因,5株菌株未携带常见耐药基因。NG-Test CARBA 515 min内检测到KPC、NDM、IMP、KPC+NDM以及NDM+IMP的敏感度和特异度均为100%。Carba NP法和mCIM法的敏感度分别为93.94%、96.97%,特异度分别为80.00%、100.00%,与基因测序结果一致性Kappa值分别为0.857、0.902(P<0.05)。20株耐碳青霉烯肠杆菌科细菌模拟血培养,大肠杆菌、阴沟肠杆菌、肺炎克雷伯菌、产酸克雷伯菌分别有6株、5株、4株、5株,NG-Test CARBA 5敏感度和特异度均为100.0%,与基因测序结果一致性Kappa值为1.000;Carba NP法和mCIM法的敏感度分别为87.50%、93.75%,特异度均为100%,与基因测序结果一致性Kappa值分别为0.812、0.898(P<0.05)。结论NG-Test CARBA 5检测过程简单、高效,检测结果准确度高,大大简化了临床上检测碳青霉烯酶的复杂流程,有助于增强院内感染控制和及时指导临床治疗。

Objective To explore the application value of NG-Test CARBA 5 in the detection of carbapenemase content in blood cultured enterobacteriaceae bacteria.Methods A total of 62 strains of enterobacteriaceae bacteria with known gene types were collected from clinical specimens of our hospital,including 38 strains of carbapenem resistant enterobacteriaceae bacteria and 24 strains of carbapenem sensitive enterobacteriaceae bacteria.NG-Test CARBA 5 kit,Carba NP and mCIM tests were used to detect the major carbapenemases of the strains to be tested,and PCR was used to sequence the carbapenemase gene phenotypes for confirmation and Kappa consistency test.Then 20 strains were randomly selected from 38 carbapenem resistant strains for simulated blood culture,and tested with NG-Test CARBA 5 kit,Carba NP method and mCIM method and Kappa consistency test.Results The drug resistance of 38 carbapenem resistant Enterobacteriaceae strains were meropenem and/or imipenem.PCR amplification and sequencing results showed that 33 strains carried drug resistance genes,and 5 strains did not carry common drug resistance genes.The sensitivity and specificity of NG-Test CARBA 5 in detecting KPC,NDM,IMP,KPC+NDM and NDM+IMP within 15 min were 100%.The sensitivity of Carba NP method and mCIM method was 93.94%and 96.97%,respectively,and the specificity was 80.00%and 100.00%,respectively.The Kappa values were 0.857 and 0.902(P<0.05),which were consistent with the results of gene sequencing.Twenty carbapenem resistant Enterobacteriaceae bacteria were cultured in simulated blood.There were 6,5,4 and 5 strains of Escherichia coli,Enterobacter cloacae,Klebsiella pneumoniae and Klebsiella acidogenes,respectively.The sensitivity and specificity of NG-Test CARBA 5 were 100.0%,and the Kappa value was 1.000,which were consistent with the results of gene sequencing.The sensitivity of Carba NP method and mCIM method were 87.50%and 93.75%respectively,and the specificity was 100%.The Kappa values were 0.812 and 0.898(P<0.05),which were consistent with the results of gene sequencing.Conclusion The detection process of NG-Test CARBA5 is simple,efficient and accurate,which greatly simplifies the complex process of clinical detection of carbapenemase,and is helpful to enhance hospital infection control and timely guide clinical treatment.