整合子介导的大肠埃希菌临床菌株多重耐药研究

目的　了解大肠埃希菌多重耐药菌株中 1、2类整合酶基因的携带情况,研究整合子与抗生素多重耐药的相关性。方法　对 102株大肠埃希菌临床分离株做药物敏感性分析和整合子的PCR基因检测。结果　102株大肠埃希菌对 11种抗生素的耐药率为:氨苄青霉素(94% )、庆大霉素 ( 88% )、环丙沙星 ( 88% )、阿莫西林 /克拉维酸 ( 70% )、头孢唑啉 ( 62% )、头孢他啶(50% )、哌拉西林(41% )、哌拉西林 /他唑巴坦(38% )、头孢哌酮 /舒巴坦(29% )、丁胺卡那 (24% )和泰能 (2% )。102株大肠埃希菌中 51%找到不同插入大小的整合子,插入基因盒大小范围是 650bp到 2 600bp;intⅠ1整合酶基因检出率为 85%,PCR扩增出 280bp大小的intⅠ1基因片段,而未检测到intⅠ2整合酶基因。结论　1类整合子在大肠埃希菌多重耐药菌株中最常见,整合子的存在与细菌的多重抗生素耐药有密切关系。

Integron-mediated multidrug resistance in Escherichia coli clinical strains

Objective To understand the presence of the first and the second class integrase genes in the clinical isolates of Escherichia coli and investigate the correlation between integrons and multidrug resistance.Methods The antibiotic sensitivity tests were analyzed and integron genes were detected by PCR in 102 Escherichia coli clinical strains.Results The resistance rates of 102 Escherichia coli clinical strains for 11 antibiotic were as follows:94% for Ampicillin,88% for Gentamicin,88% for Ciprofloxacin,70% for AmoxicillinC,62% for Cefazolin,50% for Ceftazidime,41% for Piperacillin,38% for PiperacillinT,29% for Cefoperazone/S,24% for Amikacin and 2% for Imipenem.Integrons with various sizes of inserted gene were found in 51% of Escherichia coli strains.The range of inserted gene cassette sizes detected varied from 650 bp to 2,600 bp.IntI1 integrase genes with expected size of 280 bp were detectable in 85% of Escherichia coli strains, whereas no intI2 integrase gene were detectable in these Escherichia coli strains.Conclusions Class 1 integrons were the most common integrons found in this collection of multidrug resistant clinical isolates.The presence of integrons is closely associated with multidrug resistance of bacteria.