【摘要】 目的对临床菌株中的整合子分布及其携带耐药基因盒的结构特征进行分析。方法应用多重PCR方法检测55株临床菌株中的3类整合酶基因intI,并对intI阳性菌株耐药基因盒进行测序及序列分析。结果55株临床菌株均为第1类整合酶基因阳性(100%)。耐药基因盒特异PCR扩增发现,27株革兰阳性菌株和22株革兰阴性菌株均得到1 913 bp的扩增产物,携带基因盒为dhfro、rfF和aadA 2;6株革兰阴性菌得到1 664 bp的产物,携带基因盒为aadA 5和dfr 17。aadA 2和aadA 5均为编码对氨基糖苷类抗生素产生耐药的基因盒,dhfr和dfr 17均为编码对磺胺类药物甲氧苄氨嘧啶产生耐药的基因盒;orfF为未知功能的开放阅读框。结论临床致病革兰阳性菌和革兰阴性菌株均广泛存在着整合子结构,应加强对耐药基因在细菌种属间水平转移的监测工作。更多还原

【Abstract】 Objective To investigate the distribution and characterization of integrons in clinical strains.Methods The presence and genetic content of 3 classes integrons among 55 clinical strains were examined by multiple PCR and sequencing.Results 55(100%)strains were positive for intI1 gene.Furthermore,intI1-positive strains were amplified with primers of in-F and in-B which were set for amplifying the region of antibiotics resistance genes.Among 55 strains,an amplicon of 1?913?bp was yielded in 49 isolates,an amplicon of 1?664?bp was yielded in 6 isolates.Sequencing analysis revealed that amplicon 1?913?bp harbored genes of dhfr,orfF and aadA?2,amplicon 1?664?bp harbored genes of aadA5 and dfr?17,adA?2 and aadA?5 showing aminoglycoside resistance;dhfr and dfr?17 conferring resistance to trimethoprim,orfF encoding unknown function.Conclusion Resistance gene(s)mediated by class 1 integron was extensively existed in clinical isolates of both gram-negative and gram-positive bacteria.The result stressed the need for continued surveillance of antibiotic resistance gene(s) horizontal transference among bacteria genus.更多还原