海南9株携带blaNDM-1基因肠杆菌科细菌的分离和确认

The isolation and identification for 9 strains of Enterobacteriaceae with blaNDM-1 in Hainan

目的分离和研究海南地区发现的携带blaNDM-1基因肠杆菌科细菌。方法回顾性研究。收集2012年海南省临床上对亚胺培南或美罗培南耐药或中介的肠杆菌科细菌30株；用法国生物梅里埃公司AP120E进行菌种鉴定和V1TEK2全自动细菌鉴定仪进行药敏试验；亚胺培南／亚胺培南和抑制剂复合物（IP／IPI）E—test试纸条法协同试验检测产金属B内酰胺酶的菌株，试验菌株进行NDM-1耐药基因PCR特异性扩增，扩增产物进行琼脂糖凝胶电泳和测序分析；将阳性菌株进行质粒接合试验，并对接合前后的药敏结果进行比较。结果30株目标细菌经IP／IPIE—test试纸条法协同试验检出阳性菌株21株，再经PCR扩增和测序获得9株携带blaNDM—1基因的耐药菌株，其中4株为肺炎克雷伯菌，2株为大肠埃希菌，2株为阴沟肠杆菌，1株为产气肠杆菌。这些携带blaNDM-1基因菌株对广谱抗生素B内酰胺酶抑制剂、头孢类、碳青霉烯类抗生素耐药；经质粒接合转移试验后，9株试验菌全部接合成功，这9株细菌的接合子药敏试验结果表示其对亚胺培南和美罗培南的药物敏感性有较大差异，对氨曲南、头孢吡肟和头孢替坦的药物敏感性有轻度差异，其他药物的敏感性无明显差异。结论海南发现的耐碳青霉烯酶类肠杆菌科细菌主要携带blaNDM-1基因，产碳青霉烯酶是肠杆菌科细菌对β内酰胺类抗生素耐药的主要机制之一，且其NDM-1可通过质粒在不同菌株之间传递。

Objective To explore blaNDM-1 gene context harboring in Enterobacteriaceae strains isolated from Hainan. Methods Retrospective study. Thirty strains of the imiperem or meropenem resistant Enterobacteriaeeae were collected in Hainan 2012 by BioMerieux API identification and bioMerieux VITEK-2 bacterial susceptibility testing system. Incidence of metallo-beta-lactamase-producing of the positive strains was examined by imipenem/imipenem and inhibitor complex （ IP/IPI ） E-test Trial. The NDM-1 gene was amplified by PCR, the product was electrophoresed and sequenced. After sequencing, the bacteria with bIaNDM-1 gene were taken to the plasmid conjugation test for retrospective comparative study. Results Of 30 strains of imiperem or meropenem resistant Enterobacteriaceae, 21 strains were positive in IP/IPI E-test Trial. Among them, 9 strains with blaNDM-1 gene, including 4 strains of K. pneumortiae, 2 strains of E. coli, 2 strains of E. cloacae and 1 strain of E, aerogenes. Those bacteria with blaNDM-1 were endowed with the ability of resistance to several antibiotics,including ^-lactamseinhibitor, cephems and carbapenems. After conjugation binding plasmid test,the strains which had captured the exotic plasmid with blaNDM-1, show strong resistance to most of the antibiotics. However, distinct difference on the resistance to imiperem and meropenem was proved by conjugation test in the 9 isolates, while less obvious difference in the resistance to aztreonam, cefepime and cefotetan. Conclusion The Carbapenems resistant Enterobacteriaceae in Hainan harbored the gene of blaNDM-1, so blaNDM-1 may play an important role in β-lactams resistance, andblaNDM-1 can be transmitted in different strains by plasmids.