肺炎克雷伯菌产超广谱β-内酰胺酶基因分型研究

目的调查广州地区下呼吸道感染肺炎克雷伯菌产超广谱β-内酰胺酶(ESBL)的分离率及各种基因型的流行病学分布。方法收集广州地区13家医院2001-10～2002-12临床分离的肺炎克雷伯菌511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ESBL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。结果肺炎克雷伯菌产ESBL分离率为40.1%。TEM型49株占21.9%,均为TEM-1型;CTX-M型59株占28.8%;SHV型96株占46.8%。结论SHV型是广州地区下呼吸道感染肺炎克雷伯菌产ESBL流行的常见基因型。

Genotype characterization of extended-spectrum β-lactamases in Klebsiella pneumoniae

Objective To investigate the prevalence,phenotypical and genotypical characteristics of extended-spectrumβ-lactamases in Klebsiella pneumoniae in lower respiratory tract infections in Guangzhou.Methods A total of 511 strains of nonrepetitive K. pneumoniae were collected from Oct, 2001 to Dec, 2002 in 13 different hospitals of Guangzhou and investigated for the production of extended-spectrumβ-lactamases (ESBL),by phenotypic screening and confirmatory test provided by the National Committee for Clinical Laboratory Standards ESBL genotypes were analyzed by isoelectric point determinayion,PCR and uncleotide sequencing.Results The ESBL positive rate of K.pneumoniae was 40.1%,TEM were 21.8%,all of them were TEM-1,CTX-M were 28.8%,SHV were 46.8%.Conclusion SHV-type is predominant genotype of ESBL in lower respiratory tract infections in Guangzhou.