【摘要】 目的研究大肠埃希菌和肺炎克雷伯菌中产质粒型 AmpC 酶株的比率、酶的基因型及其流行病学状况。方法收集本院、福建省立医院两家医院2004年9月至2005年3月的67株耐头孢西丁不重复大肠埃希菌和肺炎克雷伯菌,用酶提取物三维试验检测高产 AmpC 酶;抽提高产 AmpC酶株质粒,用 PCR 及产物序列分析确定质粒 AmpC 酶和β内酰胺酶的基因型;质粒转化试验定位耐药基因;ERIC-PCR 指纹图确定产酶株间的同源关系。结果福州两家医院耐头孢西丁菌中产质粒型 AmpC 酶的发生率,大肠埃希菌分别为16.7%和10.5%,肺炎克雷伯菌则分别为8.0%和0。2株肺炎克雷伯菌产 DHA-1型、4株大肠埃希菌产 CMY-2型、1株大肠埃希菌产 CMY-22型质粒 AmpC酶;5株产 CMY 型 AmpC 酶的大肠埃希菌还分别同时产 CTX-M-14、CTX-M-27、TEM-144和 TEM-1型β内酰胺酶。7株菌中,1株肺炎克雷伯菌和3株大肠埃希菌可将头孢西丁耐药性转移给受体菌。7株产酶菌 ERIC-PCR 指纹图显示,2株肺炎克雷伯菌来自相同克隆,其余菌株来自不同克隆。结论福州地区发现产 DHA-1型 AmpC 酶肺炎克雷伯菌和产 CMY-2型及 CMY-22型 AmpC 酶大肠埃希菌。CMY-22型 AmpC 酶和 TEM-144型β内酰胺酶是国内外首次报道,GenBank 登录号为 DQ256079和DQ256080。更多还原

【Abstract】 Objective To investigate the prevalence,genotype and epidemiology of plasmid- mediated AmpC enzyme of Escherichia coli and Klebsiella pneumoniae.Methods A total of 67 clinical isolates of nonrepetitive cefoxitin-resistant Escherichia coli and Klebsiella pneumoniae collected by Fuzhou General Hospital and Fujian Provincial Hospital during a period of Sept.2004 to Mar.2005 were detected by three-dimensional extract test for AmpC enzyme,and PCR for AmpC enzyme and other β-lactamase gene amplification and DNA sequencing were carried out for genotype of β-lactamase.Plasmid transformation experiment was used to study the transfer of cefoxitin resistance.The homology of the isolates was determined by ERIC-PCR fingerprinting.Results At two hospitals in Fuzhou,the prevalence of plasmid-mediated AmpC enzyme among cefoxitin-resistant Escherichia coli and Klebsiella pneumoniae were 16.7% and 10.5%, 8.0% and 0,respectively.Two isolates of Klebsiella pneumoniae produced DHA-1 plasmid-mediated AmpC enzyme,and 4 isolates of Escherichia cob and one strain of Escherichia coli produced CMY-2 and CMY-22 plasmid-mediated AmpC enzyme respectively.Furthermore,5 strains of Escherichia coli with CMY AmpC enzyme were also found simuhaneously to produce TEM-144,CTX-M-27,CTX-M-14 and TEM-1 β-lactamase respectively.Three strains of Escherichia coli and one isolate of Klebsiella pneumoniae could transfer cefoxitin resistance to acceptant bacillus.ERIC-PCR fingerprinting reveals 2 strains of Klebsiella pneumoniae came from same clone,but 5 strains of Escherichia coli came from different clones.Conclusions The clinical isolates of Klebsiella pneumoniae producing DHA-1 plasmid-mediated AmpC enzyme and Escherichia coli producing CMY-2,CMY-22 plasmid-mediated AmpC enzyme are found in Fuzhou.CMY-22 AmpC enzyme and TEM-144 β-lactamase are the first reported in the world,GenBank accession number: DO256079,DO256080更多还原