河北省发现携带NDM-1型金属β-内酰胺酶基因的阴沟肠杆菌临床分离株

Detection of Carbapenemase NDM-1 in Carbapenem-resistant Enterobacter Cloacae in Hebei Province

目的 对河北省细菌耐药监测网收集的耐碳青霉烯类抗生素肠杆菌进行筛查与鉴定,以了解其耐药机制.方法 选择2011年10月～2012年10月河北省细菌耐药监测网收集的耐碳青霉烯类抗生素的肠杆菌临床菌株,采用纸片扩散法和E-test法检测耐药性,改良Hodge试验和金属酶试验检测产酶类型,聚合酶链反应（PCR）检测耐药基因并进行测序.结果 50株耐碳青霉烯类抗生素的肠杆菌中检测到一株对亚胺培南和美洛培南高度耐药的阴沟肠杆菌,亚胺培南和美洛培南对阴沟肠杆菌的抑菌环直径均为6 mm.E-test法测得亚胺培南和美洛培南的MIC均＞32 μg/ml,改良Hodge试验结果阳性,金属酶表型初筛试验阳性.经上海生物工程公司ABI测序仪测序后,并与GeneBank比对,表明与NDM-1基因有99%的相似性.结论 河北省发现1株对碳青霉烯类抗生素高度耐药的阴沟肠杆菌,经进一步试验证实为产NDM-1金属酶.

Objective To investigate the resistance mechanism of carbapenem resistant Enterobacter cloacae Enterobacteriacea in hebei antimierobiolmicrobiol resistantnet. Methods The Enterobacteriaceae isolates resistant to carbapenemase were col- lected from October of 2011 to October of 2012. Antimicrobiol resistant test were determinated by K-B test and E-test. Isolates were screened for phenotype by modified Hodge test and metalloenzyme test. PCR amplification was used to analiyze the existence of β-laetamase gene. Reults A total of 50 strains of Enterobacteriaceae resistant to carbapenemase were isola ted, 1 of 50 was Enterobacter cloacae. The inhibitory diameter of Imipenem and Meropenem againistst Entobacter cloacae was 6mm by K-B method, MIC of Imipenem and Meropenem was ~ 32 μg/ml by E-test. Modified Hodge test showed posi- tivenegative and,but metaUoenzyme test was positive. β-lactamase gene NDM-1 were identified by PCR and sequence analysis was 99% similarity to NDM-1 by GeneBank. Conclusion β-1actamase gene NDM-1 were firstly identified in Enterobacter cloacae in Hebei province.