产ESBLs肺炎克雷伯杆菌和大肠杆菌的耐药性分析及TEM基因的测序

Drug resistance analysis and TEM genotypes of Klebsiella pneumoniae and Eschenchia coli producing ESBLs

目的了解成都地区产超广谱β-内酰胺酶(ESBLs)的肺炎克雷伯杆菌和大肠杆菌的耐药情况及TEM基因亚型分布。方法采用美国临床实验室标准化委员会(CLSI)推荐的表型确认方法,对成都地区近三年临床收集的无重复的165株肺炎克雷伯杆菌和大肠杆菌进行菌株筛选;采用K-B纸片扩散法,对分离株进行药物敏感实验。用TEM引物对产ESBLs菌株进行PCR扩增,并对产物测序。结果 165株肺炎克雷伯杆菌和大肠杆菌中共检出125株产ESBLs,检出率为76.2%。亚胺培南对产ESBLs肺炎克雷伯杆菌和大肠杆菌表现出较高抗菌活性,敏感率为100%,阿莫西林敏感率为0。对25株含TEM型的菌株进行测序,全部为TEM-1型非ESBLs。结论亚胺培南是目前治疗产ESBLs肺炎克雷伯杆菌和大肠杆菌感染最有效的药物。成都地区肺炎克雷伯杆菌和大肠杆菌以TEM-1型β-内酰胺酶为主。

OBJECTIVE To investigate the drug resistance of extended - spectrum β - lactamases （ESBLs） in Klebsiella pneumoniae and Escherichia coli from Chengdu and confirm the TEM genotype. METHODS 165 strains Klebsiella pneumoniae and Escherichia coli obtained by non - repeat clinical separation in Chengdu region from 2010 to 2012. The ESBLs - producing isolates of Klebsiella pneu- moniae and Escherichia coli were confirmed by Clinical and Laboratory Standards Institute（CLSI） phenotypic confirmatory test. Antimi- crobial susceptibility was tested by disk diffusion test （ K - B method） , PCR was performed using primers specific for blaTEM, DNA sequencing were carried out for genotyping. RESULTS The positive rate of Klebsiella pneumoniae and Escherichia coli producing ESBLs was 76.2%. Klebsiella pneumoniae and Escherichia coli had 100% susceptible rate to imipenem, and 0 susceptible rate to amoxi- cillin. All of 25 strains were TEM - 1. CONCLUSION Imipenem is the most effective antibiotics against extended - spectrum β - lac- tamases in Klebsiella pneumoniae and Escherichia coli. TEM - 1 was the most prevalent genotype of β- lactamases in Chengdu.