浙江省丽水地区NDM菌株的耐药特征及基因背景研究  

Drug resistance and genetic background of New Delhi metallo-β-1actamase （NDM）-producing bacterial strains in Lishui area of Zhejiang province

作　　者：黄建胜[1] 余璟璐[1] 朱艳[1] 胡晓蕾[1] 任建敏[1] 赵赟安 丁卉[1] 武蓉珍[1] 赵志钢[1] Huang Jiansheng;Yu Jinglu;Zhu Yah;Hu Xiaolei;Ren Jianmin;Zhao Yunan;Ding Hui;Wu Rongzhen;Zhao Zhigang(Clinical Laboratory,Lishui Municipal Central Hospital,Lishui 323000,Zhejiang Province,China)

机构地区：[1]浙江省丽水市中心医院检验科,323000

出　　处：《中华临床感染病杂志》2018年第4期287-293,共7页Chinese Journal of Clinical Infectious Diseases

基　　金：浙江省医药卫生科技项目（2018KY935）;丽水市重点研发计划项目（2017ZDYF13）

摘　　要：目的 分析浙江省丽水地区产NDM菌株的耐药表型及基因结构特征,为临床抗感染治疗和防控提供实验依据.方法 收集浙江省丽水市中心医院2012年1月至2016年12月临床分离的所有无重复亚胺培南耐药性肠杆科细菌,以梅里埃Vitek 2 Compact系统鉴定菌种并以PCR筛选blaNDM基因阳性菌株,采用KB法和GN13卡检测菌株药敏性,利用复制起始子分析法鉴定质粒类型,通过转化或接合试验纯化质粒并采用PCR和全基因组测序分析blaNDM周围基因结构.结果 共分离碳青霉烯耐药肠杆科细菌（CRE）菌株102株,其中blaNDM阳性15株,阳性检出率为14.7%,主要为大肠埃希菌和阴沟肠杆菌.各菌株对β-内酰胺类抗菌药物的耐药率为100%,对氨曲南、复方磺胺甲噁唑、妥布霉素、庆大霉素的耐药率均＞80%;对喹诺酮类药物的耐药率＞50%. 15株产NDM菌株中, 12株改良Hodge试验阳性,另有2株阴沟肠杆菌和1株大肠埃希菌呈阴性结果.其中blaNDM-1型11株,blaNDM-5型4株.检到IncX3、IncFIIγ和IncA/C等多种质粒类型,且4例blaNDM-5基因均位于IncX3质粒.发现4 种 blaNDM周围基因结构,其中8 例 blaNDM-1基因位于 ISAb125-hyp-blaNDM-1-bleMBL-TrpF-DsbC-IS26,而blaNDM-5均位于IS3000-IS5-blaNDM-5-bleMBL-TrpF-DsbC-IS26结构,且前者在国内尚属首次报道.结论 丽水地区NDM菌株呈低水平流行,并对磷霉素和多黏菌素敏感性较高;blaNDM基因可能有多种来源,但IncX3型质粒仍是介导该基因转移的主要原因,并发现新型blaNDM-1基因结构.Objective To analyze the drug resistance phenotype and genetic background of New Delhi metallo-β-lactamase （NDM）-producing bacterial strains in Lishui area of Zhejiang province.Methods The imipenem-resistant Enterobacteriaceae strains were isolated from January 2012 to December 2016 in Lishui Municipal Central Hospital of Zhejiang Province.Mrieux Vitek 2 Compact system was used to identified strains and PCR was used to screen for blaNDMgene.Susceptibility was detected by K-B method and MICs were obtained by Vitek 2 with GN13 cards.Plasmids typing was carried out by DNA sequencing of the replication initiator with the transconjugates as templates.The blaNDMgenetic contexts were detected by PCR and complete genome sequencing.Results A total of 102 strains of carbapenem-resistant enterobacteria （CRE）, mainly Escherichia coli and Enterobacter cloacae, were isolated, of which 15 were positive for blaNDMwith a positive detection rate of 14.7%.The resistance rate to β-lactam antibiotics was 100%, and the resistance rates to aztreonam, compound sulfamethoxazole , tobramycin and gentamicin were all 〉80%;and the resistance rate to quinolones was 〉50%.Among the 15 NDM-producing strains , 12 strains were positive for Hodge test, and 2 strains of Enterobacter cloacae and 1 strain of Escherichia coli were negative. There were 11 strains of blaNDM-1and 4 strains of blaNDM-1.A variety of plasmid types such as IncX 3, IncFIIγ and IncA/C were detected, and 4 blaNDM-5genes were located in the IncX3 plasmid.Four blaNDMsurrounding gene structures were found, of which 8 blaNDM-1genes were located in ISAb125-hyp-blaNDM-1-bleMBL-TrpF-DsbC-IS26, while blaNDM-5was located in IS3000-IS5-blaNDM-5-bleMBL-TrpF-DsbC-IS26 structure, and the former was reported for the first time in China.Conclusion NDM-producing bacterial strains in Lishui area are prevalent at a low level and have high sensitivity to fosfomycin and polymyxin .The blaNDMgene may have multiple sources, but IncX3 plasmid is still the main source for gene transfer.S

关 键 词：Β内酰胺酶类 NDM 耐药特征 基因背景 

分 类 号：R392.11[医药卫生—免疫学]