产超广谱β-内酰胺酶表型及基因型分布

Phenotype and Genotype Distribution of Extended spectrum β-Lactmases in Clinical Isolates Producing ESBLs in Huaibei Area of Anhui

目的 了解淮北地区 3 所医院,临床分离产超广谱β 内酰胺酶(ESBLs)大肠埃希菌和肺炎克雷伯菌中ESBLs表型和基因分布。方法 用1999年NCCLS推荐的初筛试验,从 147 株大肠埃希菌和肺炎克雷伯菌中筛选出可疑产ESBLs细菌,并用确证试验加以确认,然后用 PCR的方法扩增其基因型。结果 116 株大肠埃希菌和31株肺炎克雷伯菌中,共检出69株产ESBLs(46 9%),其中大肠埃希菌 51 株(42 2%),肺炎克雷伯菌 18 株(58 1%);将初筛得到的可疑菌株用纸片扩散确证法,头孢噻肟和头孢噻肟/克拉维酸测定,检出 69 株产 ESBLs细菌,而用头孢他啶和头孢他啶/克拉维酸检测ESBLs阳性菌为32株;PCR扩增基因型阳性结果为TEM型 119株、SHV型10株、CTX M型68株、OXA型 18 株。结论 淮北地区 ESBLs的检出率为 46 9%,头孢噻肟检测ESBLs的敏感性明显高于头孢他啶;基因型以CTX M型为主,有些菌株同时携带≥2种耐药基因。

OBJECTIVE To study the phenotype and genotype distribution of ESBLs in extended spectrum β lactamases (ESBLs) producing Klebsiella pneumoniae and Escherichia coli strains isolated from three hospitals in Huaibei area of Anhui. METHODS A total of 147 strains of K. pneumoniae and E. coli conserved were determined by 1999 NCCLs methods. Then the genotype of ESBLs was amplified by polymerase chain reaction (PCR). RESULTS Sixty nine of 147 K. pneumoniae and E. coli isolates were classified with TEM type, SHV type, CTX M type, TOHO type and OXA type ESBLs genes. The positive results of Enterobacteriaceae carrying TEM type, SHV type, CTX M type ESBLs were 119 strains, 10 strains, 68 strains and 18 strains, respectively. CONCLUSIONS The positive rate of ESBLs producing Enterobacteriaceae is 46 9%. CTX is more sensitive than CAZ. The rate of CTX M type ESBLs producing K. pneumoniae and E. coli reaches a high level in the hospitals in Huaibei. There are some strains carrying two genotype or more.