CIM和Carba NP筛选铜绿假单胞菌产碳青霉烯酶比较

Detection of carbapenemase activity in Pseudomonas aeruginosa: Comparison of the carbapenem inactivation method with the Carba NP test

目的评估碳青霉烯类抑制法(carbapenem inactivation method,CIM)和Carba NP对铜绿假单胞菌碳青霉烯酶表型的筛选能力。方法选取河北省医学微生物菌种保藏库(Hebei Provincial Bank for Medical Culture Collections,HBMCC)保存的碳青霉烯类耐药铜绿假单胞菌146株,分别用CIM和Carba NP法检测碳青霉烯酶活性,采用PCR方法检测VIM-1、KPC-2、IMP-4、NDM-1基因。结果 146株铜绿假单胞菌中有11株Carba NP阳性,阳性率为7.5%(11/146);13株CIM阳性,阳性率为8.9%(13/146)。9株碳青霉烯酶编码基因阳性,其中6株VIM-1阳性,1株VIM-1和IMP-4同时阳性,2株KPC-2阳性;碳青霉烯酶编码基因阳性的菌株Carba NP和CIM均阳性;5株基因检测阴性菌株中1株仅Carba NP阳性,3株仅CIM阳性,1株Carba NP和CIM均阳性。结论 CIM能够准确快速筛选铜绿假单胞菌碳青霉烯酶活性,是一种经济高效的表型筛选方法。

Objective To evaluate the screening capability of carbapenem inactivation method（ CIM） and Carba NP test for the carbapenemase activity phenotype of Pseudomonas aeruginosa. Methods 146 isolates of Pseudomonas aeruginosa from Hebei Provincial Bank for Medical Culture Collections（ HBMCC） were selected,and carbapenemase activity were determined by the CIM and Carba NP test,respectively. Meanwhile,the carbapenemase genes such as VIM-1,KPC-2,IMP-4 and NDM-1 were detected by PCR. Results Eleven of 146 strains（ 7. 5%） were positive for Carba NP,while 13 of 146 strains（ 8. 9%） for CIM. There were 9 of 146 strains carrying carbapenemase genes,including six for VIM-1,one for both VIM-1 and IMP-4,and two for KPC-2. The strains carrying carbapenemase genes were positive for Carba-NP and CIM. There were five strains with positive CIM or Carba NP but negative carbapenemase gene,including one positive for Carba NP,three for CIM and one for both Carba NP and CIM. Conclusion The CIM,a lowcost and highly effective phenotype-screening method,can accurately and rapidly detect the carbapenemase activity.