血培养大肠埃希菌的耐药特点、毒力基因分布及种系分型  

Drug resistance characteristics,virulence gene distribution,and phylogenetic typing of Escherichia coli in blood culture

作　　者：马小轩 翟俊斌 曹小利[1] 张燕[1] 郑洁[1] 张之烽[1] 沈瀚[1] MA Xiaoxuan;ZHAI Junbin;CAO Xiaoli;ZHANG Yan;ZHENG Jie;ZHANG Zhifeng;SHEN Han(Department of Clinical Laboratory,Nanjing Drum Tower Hospital,Nanjing 210008,Jiangsu,China)

机构地区：[1]南京大学附属鼓楼医院检验科,南京210008

出　　处：《临床检验杂志》2024年第5期321-326,共6页Chinese Journal of Clinical Laboratory Science

基　　金：国家自然科学基金(81902124);南京市卫生青年人才培养工程(QRX17059)。

摘　　要：目的检测并分析血培养大肠埃希菌的耐药特点、种系分型和毒力基因分布。方法收集我院2019年1月1日至2020年12月13日连续且非重复血培养大肠埃希菌。采用微量肉汤法测定大肠埃希菌对17种抗菌药物的敏感性;水煮法提取细菌基因组DNA,采用PCR法检测arpA、chuA、yjaA、TspE4C2、ArpAgpE和trpAgpC基因以确定细菌的种系分型;采用多重PCR法检测毒力基因iutA、fimH、fyuA、kpsMTⅡ、cnf1、cvac、hlyA、traT、kpsMTⅢ和PAI;使用卡方检验分析种系分型之间的耐药率及毒力基因分布差异。结果270株血培养大肠埃希菌对头孢曲松、复方新诺明、氨苄西林、氨苄西林/舒巴坦、头孢唑林和环丙沙星的耐药率较高,均大于50.0%;对亚胺培南、厄他培南、阿米卡星和哌拉西林/他唑巴坦的敏感性较高,耐药率均低于5.0%。在种系分型方面,最常见的型别是B2型和D型,分别占总数的38.0%和16.2%,而E型和隐分支Ⅰ型占比<1.0%,较为少见。毒力基因分析发现,fimH和fyuA基因的分布率最高,均在99.0%以上,而kpsMTⅢ、hlyA和cvaC 3种基因的分布率较低,均低于20.0%。卡方检验显示,毒力基因iutA、fimH、fyuA、kpsMTⅡ、cnf1、PAI在B2型的分布显著高于非B2型(P<0.05),且B2型携带的iutA、fyuA、kpsMTⅡ、cnf1、PAI基因显著高于D型(P<0.05)。结论在治疗引起血流感染的大肠埃希菌时,应慎用头孢曲松、复方新诺明、氨苄西林、氨苄西林/舒巴坦、头孢唑林和环丙沙星等药物。血流感染的大肠埃希菌为B2型时,应同时进行中段尿培养以确认感染源并监测治疗的成功率。Objective To detect and analyze the drug resistance characteristics,phylogenetic typing,and virulence gene distribution of Escherichia coli(E.coli)in blood culture.Methods The strains of E.coli isolated from consecutive non-repetitive blood cultures in our hospital from January 1,2019 to December 13,2020 were collected.The sensitivity of E.coli to 17 antibiotics was determined using the micro-broth method.The bacterial genomic DNA was extracted using the boiling method,and then the arpA,chuA,yjaA,TspE4C2,ArpAgpE and trpAgpC genes were detected by PCR to determine the bacterial phylogroup.The virulence genes,including iutA,fimH,fyuA,kpsMTⅡ,cnf1,cvac,hlyA,traT,kpsMTⅢ,and PAI,were detected using the multiplex PCR.The differences in drug resistance and virulence gene distribution among different phylogroups were analyzed by the Chi-square test.Results 270 strains of E.coli in blood culture showed high resistance rates to ceftriaxone,compound sulfamethoxazole,ampicillin,ampicillin sulbactam,cefazolin,and ciprofloxacin,all exceeding 50.0%.They had good susceptibility to imipenem,ertapenem,amikacin,and piperacillin tazobactam,with resistance rates all below 5.0%.The most common phylogroups were types B2 and D,accounting for 38.0%and 16.2%,respectively,while type E and hidden branch type I were relatively rare,accounting for less than 1.0%.The virulence gene analysis revealed that the distribution rates of fimH and fyuA genes were the highest,both above 99.0%.The distribution rates of kpsMTⅢ,hlyA,and cvaC genes were relatively low,all below 20.0%.The Chi-square test showed that the distribution rates of virulence genes such as iutA,fimH,fyuA,kpsMTⅡ,cnf1,and PAI in the B2 group were significantly higher than those in the non-B2 group(P<0.05).The distribution rates of iutA,fyuA,kpsMTⅡ,cnf1,and PAI genes in the B2 group were significantly higher than those in the D group(P<0.05).Conclusion When treating bloodstream infections caused by E.coli,caution should be exercised in the use of drugs such as ceftriaxone,comp

关 键 词：大肠埃希菌 耐药 毒力基因 种系分型 

分 类 号：R446.5[医药卫生—诊断学]