广州地区呼吸道感染产超广谱β-内酰胺酶基因分型研究

Genotype Characterization of Extended-Spectrum β-Lactamases in Lower Respiratory Tract Infections in Guangzhou Area

目的:调查广州地区下呼吸道感染产超广谱β-内酰胺酶(ESBL )大肠埃希菌和肺炎克雷伯菌的分离率及各种基因型的流行分布。方法:收集广州地区13家医院2 0 0 0 - 10～2 0 0 1- 12临床分离的大肠埃希菌和肺炎克雷伯菌共714株,采用美国临床实验室标准化委员会规定的ESBL表型筛选和确证试验确定ESBL的发生率、PCR扩增对产ES-BL菌初步分型,然后对部分PCR扩增阳性产物测序,序列分析进一步确定基因型。结果:大肠埃希菌和肺炎克雷伯菌产ESBL分离率分别为5 8.1%和4 0 .1% ;TEM型16 1株(49.8% ) ,均为TEM- 1型,CTX- M型10 7株(33.1% ) ,SHV型14 1株(43.6 % )。结论:CTX- M型和SHV型是广州地区下呼吸道感染产ESBL大肠埃希菌和肺炎克雷伯菌中流行的基因型。

Objective:To investigate the prevalence, phenotypical and genotypical characteristics of extended-spectrumβ-lactamases in Escherichia cali and Klebsiella pneumoniae in lower respiratory tract infections in Guangzhou.Methods:A total of 714 strains of nonrepetitive E. cali and K. pneumoniae were collected from October 2000 to December 2001 in thirteen different hospitals in Guangzhou and investigated for the production for extended-spectrumβ-lactamases (ESBL), by phenotypic screening and confirmatory test provided by the National Committee for Clinical Labaratory Standards ESBL genotypes were analyzed by isoelectric point determinayion,PCR and uncleotide sequencing.Results:The ESBL positive rate of E.coli was 58.1%, K. pneumoniae was 40.1%,TEM were 49.8%,all of them were TEM-1,CTX-M were 33.1%,SHV were 43.6%.Conclusions:This study showed that CTX-M-type and SHV-type were predominant genotypes of ESBL in lower respiratory tract infections in Guangzhou.