禽大肠埃希菌致病性是多种毒力因子相互作用的结果，而毒力因子与细菌的耐药性密切相关。超广谱β-内酰胺酶(ESBLs)是细菌对三代头孢耐药的主要机制，大肠埃希菌是ESBLs最主要的产生菌。ESBLs基因型有多种，其中CTX-M型已成为最为流行的基因型。CTX-M-90和CTX-M-65为2009年在河南省禽大肠埃希菌中发现的两个亚型，且已广泛扩散。本项目以多株产CTX-M-90/CTX-M-65禽大肠埃希菌为研究对象，从菌株的分型特征、质粒特性及基因环境等探索CTX-M-90和CTX-M-65基因广泛散播的原因。采用多重PCR和荧光定量PCR等技术探讨受试菌种系发育类型、MLST分型和毒力因子变化规律，分析细菌致病性与CTX-M型、系统发育背景及毒力因子三者之间相关性。为产CTX-M禽大肠埃希菌毒力因子靶位药物研发提供新的切入点，并为有效防控产CTX-M禽大肠埃希菌散播及感染提供理论依据。

Avian Escherichia coli pathogenicity results from virulence factors, which presence correlate closely with resistance. It is the major mechanism of resistance to the third generation cephalosporins that the bacteria could produce extended spectrum beta-lactamases (ESBLs). The major ESBL producer is Escherichia coli worldwide. The ESBLs contain many genotypes(for example TEM, SHV, CTX-M,et al ),recently the CTX-M genotype has been the most popular ones in the world. The CTX-M-90 and the CTX-M-65 subtypes were two novel enzymes in Avian Escherichia coli in Henan province, 2009. About fifties CTX-M-90/CTX-M-65 producing Avian Escherichia coli had been collected recent years in our laboratory, which will be included in this reaserch. The extensive dissemination mechanism of CTX-M-90 and CTX-M-65 genes will be conducted by strain molecular typing, plasmid property, and gene environment. The potential pathogenicities of CTX-M-90/CTX-M-65 producing Avian Escherichia coli will be discussed by exploring phylogenies and virulence factors, and by analyzing relationship among the CTX-M genotypes, the phylogenies and the virulence factors in the strains. The results will provide a new method to explore novel antimicrobial agents aimed at virulence factor targets, and profit to prevention and control disseminations and infections of CTX-M-producing Avian Escherichia coli.