食品和腹泻患者分离耐环丙沙星大肠埃希菌耐药特征及耐药机制的比较研究  

Comparative study on the characteristics and mechanisms of ciprofloxacin resistant Escherichia coli isolated from food and diarrheic patients

作　　者：白莉[1] 甘辛[1] 王丽丽[2] 杨小蓉[3] 张秀丽[4] 陈倩[2] 李凤琴[1] 徐进[1] BAI Li GAN Xin WANG Li-li YANG Xiao-rong ZHANG Xiu-li CHEN Qian LI Feng-qin XU Jin(Key Laboratory of Food Safety Risk Assessment of Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing 100021, China Institute for Nutrition and Food Hygiene, Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, China Center for Disease Control and Prevention of Sichuan Province, Sichuan Chengdu 610041, China Center for Disease Control and Prevention of Henan Province, Henan Zhengzhou 450016, China)

机构地区：[1]国家食品安全风险评估中心卫生部食品安全风险评估重点实验室,北京100021 [2]北京市疾病预防控制中心营养与食品卫生所食物中毒诊断溯源技术北京市重点实验室,北京100013 [3]四川省疾病预防控制中心,四川成都610041 [4]河南省疾病预防控制中心,河南郑州450016

出　　处：《中国食品卫生杂志》2017年第2期121-125,共5页Chinese Journal of Food Hygiene

基　　金：北京市自然科学基金(7154252);北京市优秀人才培养资助青年拔尖个人项目(2015000021223ZK35)

摘　　要：目的从食品和腹泻患者中分离耐环丙沙星大肠埃希菌进行耐药性及相关分子特征的研究。方法从645株食品和腹泻患者来源的大肠埃希菌中确定21株(3.3%)环丙沙星耐药菌株,并对分离株进行药敏试验,采用聚合酶链式反应和核苷酸序列分析技术对环丙沙星耐药菌株进行喹诺酮类染色体、质粒编码耐药机制、超广谱β-内酰胺酶耐药机制及系统发育分型研究。结果 21株环丙沙星耐药菌株均为多重耐药菌株,所有菌株分别在gyrA、parC和parE发生1~4个点突变,其中16株菌携带了质粒介导的喹诺酮耐药基因,包括oqx A、oqxB、qnrS、aac(6')-Ib-cr和qepA,同时所有分离株均携带bla基因。结论本研究提示食品和腹泻患者来源的耐环丙沙星大肠埃希菌耐药机制具有多样性的特点,编码耐药基因质粒存在潜在的传播可能,对公众健康产生巨大威胁。需进一步开展此类耐药菌株的监测,为研究此类菌株在食品和人群中的可能传播和评估其对人群的健康风险提供基础数据。Objective This study aimed to describe the prevalence and the characterization of resistance mechanisms of ciprofloxacin resistant Escherichia coli isolated from food and patients in China.Methods Ciprofloxacin resistant Escherichia coli isolates were selected from 645 isolates in ciprofloxacin containing plates.Antimicrobial susceptibility testing,phylogenetic analysis,quinolone and blaCTX-Mresistance mechanisms were detected by polymerase chain reaction and sequencing were carried out.Results Totally,twenty one（3.3%） ciprofloxacin resistant Escherichia coli isolates were identified.Point mutations in topoisomerase encoded genes gyr A,par C and par E were confirmed,and all isolates carried plasmid-mediated quinolone resistance genes（PMQR）,including oqxA,oqxB,qnrS,aac（6＇）-Ib-cr and qep A but qnrA,qnrB,qnrC and qnrD were not detected.All 21 ciprofloxacin resistant isolates also harbored bla_（CTX-M） genes.Conclusion The isolates from food and patients showed complicated and diverse quinolone resistance mechanisms and thepossible transmission of PMQR may pose potential risk to public health.In order to investigate aspects of transmission between food and community-acquired strains and to provide a scientific basis for humans,the continuous surveillance of multidrug-resistant Escherichia coli should be carried out.

关 键 词：环丙沙星 大肠埃希菌 耐药机制 食源性致病菌 比较 食品分离株 腹泻患者分离株 

分 类 号：R446.5[医药卫生—诊断学]