Carba NP试验检测多重耐药革兰阴性杆菌产碳青霉烯酶效果分析

Analysis of carbapenemase-producing multidrug-resistant gram-negative bacilli by Carba NP test

目的评估Carba NP试验检测多重耐药革兰阴性杆菌产碳青霉烯酶的效果。方法收集我院2010-2013年59株多重耐药革兰阴性杆菌,采用VITEK-2全自动细菌鉴定药敏系统进行种属鉴定并检测菌株对碳青霉烯类药物的敏感性,用Carba NP试验检测菌株产碳青霉烯酶表型,用PCR法确定碳青霉烯酶基因型,并对PCR产物进行DNA测序分析。结果 59株多重耐药革兰阴性杆菌对亚胺培南、美洛培南、厄他培南耐药率分别为62.71%、61.02%和64.41%。Carba NP试验确定33株产碳青霉烯酶菌株,分别为A类酶12株、B类酶21株,PCR法检出多种碳青霉烯酶基因,包括KPC(12株)、IMP(7株)、NDM(12株)、VIM(3株)。与PCR法比较,Carba NP试验敏感性和特异性分别为97.06%、100%。结论 Carba NP试验能简单快速地检测多重耐药革兰阴性杆菌产生的碳青霉烯酶,结果与金标准的PCR法有高度一致性,值得在临床检验中推广使用。

Objective To evaluate the efficacy of Carba NP test in the detection of carbapenemases in multidrug-resistant gram-negative bacilli. Methods Fifty-nine strains of muhidrug-resistant gram-negative bacilli were collected in our hospital from 2010 to 2013. VITEK-2 was used to identify species and the drug sensitivity to carbapenems. Carba NP test was used to detect carbapenemase-producing phenotypes.The genotype of carbapenemase-producing was determined by specific PCR and the PCR products were sequenced. Results The resistant rates of imipenem, meropenem and erptapenem were 62.71%, 61.02% and 64.41%, respectively in 59 strains of multidrug-resistant gram-negative bacilli. Carba NP test identified 33 strains of carbapenemase-producing strains, 12 strains of class A and 21 strains of class B. The strains carried a variety of carbapenemase genes, including KPC （12 strains） , IMP （7 strains） , NDM （12 strains） , and VIM （3 strains）. The sensitivity and specificity of the Carba NP test were 97.06% and 100%, respectively. Conclusion Carba NP test can detect the carbapenemase produced by multi- drug resistant gram- negative bacilli quickly and easily, and the result is highly consistent with the gold standard PCR method which allows its application in clinical microbiology practice.