大肠埃希菌对β-内酰胺类药物耐药特征及分子流行病学研究  

Drug resistant pattern to beta-lactamase drugs and molecular epidemiology of Escherichia coil

作　　者：翁幸鐾[1] 糜祖煌[2] 

机构地区：[1]宁波市第一医院检验科,315010 [2]无锡市克隆遗传技术研究所生物信息学室,214026

出　　处：《国际流行病学传染病学杂志》2011年第6期375-380,共6页International Journal of Epidemiology and Infectious Disease

摘　　要：目的调查大肠埃希菌尿液分离株中β内酰胺酶基因、AmpC酶基因和膜孔蛋白ompC基因的存在和变异情况。方法对宁波市第一医院2008年10月至2009年3月患者尿液样本中分离的大肠埃希菌（28株）采用PCR及序列分析的方法，分析15种阻内酰胺酶基因、6种AmpC酶基因和膜孔蛋白orapC基因。结果28株大肠埃希菌仅对美罗培南和亚胺培南100％敏感。所有分离菌中检出广谱p内酰胺酶基因以TEM-1．1ike为主，共17株（60．7％）、超广谱β内酰胺酶基因以CTX-M-55－like为主，共6株（21．4％）；ampC酶基因CMY-2－like3株（10．7％）；均检出膜孔蛋白ompC基因，且均存在变异。本组菌中TEM-1－like、CTX-M－55．1ike、CMY-2－like和orapC均阳性2株，3种基因同时阳性5株，2种基因同时阳性16株，只检出1种基因5株。菌株亲缘性分析显示，28株大肠埃希菌多耐药中多数菌株已发生演化，只有1号和22号株、14号和15号株这两组携带相同基因。结论本组大肠埃希菌中，β内酰胺酶基因、AmpC酶基因、ompC基因均有检出，这些基因是菌株对β酰胺类抗菌药物产生耐药的重要原因。菌株基因多态性明显。Objective To investigate the distribution and variety of beta-lactamase genes, AmpC genes and om- pC gene （outer membrane porin protein C） in E. coli strains isolated from urine. Methods From October 2008 to March 2009, 28 strains of E. coli isolated from urine were collected from Ningbo First Hospital. Fifteen kinds of beta-lactamase genes, 6 kinds of AmpC genes, and orapC gene were analyzed by PCR and verifieated by DNA sequencing. Results Twenty-eight strains of E. coli were all sensitive to imipenem and meropenem（ 100% ）. In all the strains, the main broad-spectrum β-lactamase TEM-l-like gene was detected in 17（60.7%） strains the main extended-spectrum β- laetamase CTX-M-55-1ike gene was detected in 6 （21.4%） strains; AmpC gene CMY-2-1ike was detected in 3 （10.7%） strains by DNA sequencing, respectively, ompC gene was detected in all the 28 strains, and all had mutations. Two strains were with TEM-l-like, CTX-M-55-1ike, CMY-2-hke, ompC genes all positive, 5 strains were with 3 genes positive, 16 strains were with 2 genes positive and 5 strains were with 1 gene positive. Phylogenetic analysis showed that 28 strains of multi-resistant E. coli revealed gene pelymorphism, and most strains showed sequence evolution. Only strain 1 and 22, strain 14 and 15 were the same clone and carried the same genes. Conclusions Beta-lactamase genes, AmpC genes, and ompC gene are all detected in this group of E. coli strains, and these positive genes play a key role in resistance to beta-lactam antimicrobial agents. The gene polymorphism of these strains is obvious.

关 键 词：大肠杆菌 Β-内酰胺酶基因 AMPC酶基因 ompC基因 耐药特征 

分 类 号：R446.5[医药卫生—诊断学]