Carba NP试验及Carba NP-direct试验检测产碳青霉烯酶肠杆菌的临床意义

目的：评价Carba NP试验及Carba NP-direct试验对碳青霉烯类耐药的肠杆菌科细菌碳青霉烯酶检测的临床价值。方法：收集南京医科大学附属无锡市第二人民医院2013年1月至2015年12月临床分离的各种标本耐碳青霉烯类抗生素的肠杆菌科细菌112株，同时选取碳青霉烯敏感的菌株100株作为对照组。所有菌株进行碳青霉烯酶耐药基因PCR检测、改良Hodge试验(MHT试验)、Carba NP试验(CNPt)以及Carba NP-direct(CNPt-d)试验检测。结果：碳青霉烯类耐药的肠杆菌科细菌共112株，92株携带blaKPC-2；8株携带blaNDM-1；1株携带blaVIM-2；1株携带blaIMP-4；10株不携带碳青霉烯酶基因；未检测到携带D组碳青霉烯酶基因的肠杆菌科细菌。以PCR检测的结果为标准，Carba NP试验、Carba NP-direct试验诊断菌株是否产碳青霉烯酶的敏感性和特异性均100%；改良Hodge试验诊断菌株是否产碳青霉烯酶敏感性为96%，特异性为98%。Carba NP试验及Carba NP-direct试验均在2 h内完成检测。结论：Carba NP试验和Carba NP-direct试验均能快速、准确筛查出产碳青霉烯酶的肠杆菌科细菌。Carba NP-direct试验相比Carba NP试验成本低、反应快、结果更明确，可作为表型确认实验和耐药监测的手段。

The clinical significance of Carba NP test and Carba NP-direct test in the detection of carbapenemase producing Enterobacteriaceae strains

Objective: Carba NP test and CNPt-direct were evaluated for the carbapenemase detection of carbapenem-resistantEnterobacteriaceae.Methods: We collected 112 carbapenem-resistantEnterobacteriaceae and 100 carbapenem-susceptibleEnterobacteriaceae in this study. They were isolated between January 1, 2013 and December 31, 2015 from various clinical samples and surveillance samples from the Second People’s Hospital of Wuxi Affiliated to Nanjing Medical University (Wuxi, China). Carbapenemase genes detectionby PCR, Modified Hodge test (MHT), Carba NP test (CNPt) and Carba NP-direct test (CNPt-d) were performed.Results: 92/135 carbapenem-resistantEnterobacteriaceae isolates carried blaKPC-2; 8 isolates carried blaNDM-1; 1 isolates carried blaVIM-2; 1 isolates carried blaIMP-4; non-isolates carried class D carbapenemase; 10 isolates carried non-carbapenemase genes. Carbapenemases genes PCR detection was regarded as a gold standard, the sensitivity and speciifcity of Carba NP test and CNPt-direct were 100%; the sensitivity and speciifcity of Modiifed Hodge test was 96% and 98%. Both Carba NP test and CNPt-direct can be done within 2 h.Conclusion:CNPt and the CNPt-d are accurate for rapid carbapenemase detection. CNPt-direct is cheaper, faster and more deifnite, CNPt-d is very promising, for epidemiological and infection control purpose.