携带bla_(NDM-1)基因的肠杆菌科细菌耐药流行特征分析

Resistance and epidemiology of bla_(NDM-1) gene in Enterobacteriaceae

目的了解昆明医科大学第一附属医院携带bla_(NDM-1)基因的肠杆菌科细菌的分子流行特征。方法收集昆明医科大学第一附属医院2011年12月—2014年10月临床送检的非重复标本,通过VITEK-2系统鉴定耐碳青酶烯类肠杆菌科细菌(CRE),EDTA协同纸片法进行金属酶表型确证,PCR技术检测bla_(NDM-1)基因的携带情况,最后采用ERIC-PCR技术分析菌株的同源性,明确待测菌株的耐药流行特征;结果 (1)共收集到206株CRE菌株,产bla_(NDM-1)的有42株(20.0%),其中以弗氏柠檬酸杆菌(43.0%)为主,主要分离自移植中心的尿液标本中;(2)药敏结果显示实验菌株均为多重耐药株,但磷霉素(5.4%)、阿米卡星(12.0%)和呋喃妥因(18.7%)等抗菌药物的耐药率相对较低;(3)金属酶表型确证的阳性率为95.0%;(4)ERIC-PCR结果显示弗氏柠檬酸杆菌、阴沟肠杆菌和大肠埃希菌在本院移植中心存在局部克隆播散;另外有4株分离自儿科的肺炎克雷伯菌电泳图谱相同。结论本院携带bla_(NDM-1)基因的肠杆菌科细菌高度流行,尤其是移植中心存在不同菌种的克隆播散型,应引起我们高度重视。

Objective To characterize the molecular epidemiology of carbapenem resistant Enterobacteriaceae （CRE） containing bla^u.l in Kunming Medical University. Methods The strains were collected between December 2011 and October 2014 from patients in the First Affiliated Hospital of Kunming Medical University, which were identified as CRE by VITEK-2. The metallo-β-1actamases （MBL） tests and PCR amplication of blaNDM-1 were performed. Then, the homogeneity of strains was analyzed by enterobacterial repetitive intergenic consensus （ERIC-PCR）. Results In total, 206 CRE were identified, and 42（20.0%） of them were positive for blaNDM-1, which were mainly Citrobacterfreundi isolated from department of transplantology in urine; antimicrobial susceptibility tests showed that most of the strains were multidrug resistant, however, the resistance rates to fosfomycin（5.4%）, amikacin （12.0%） and nitrofurantoin （18.7%） were relatively low; 95.0% of the strains were positive for MBL phenotype confirmation tests; ERIC-PCR showed that a local clonal dissemination was occurred in the department of transplantology in our hospital, which were mainly Citrobacterfreundi, Enterbacter cloacae, and Escherichia coil In addition, four strains of Klebsiella pneumoniae in the department of pediatrics belonged to the same genotype. Conclusion NDM-1 type carbapenemases produced by CRE were highly prevalent in our hospital. Especially, there was a small-scale epidemics in the department of transplantology, which was urgent and necessary to prevent.