88株肺炎克雷伯菌中Ⅰ类整合子的分布和耐药性分析

Relationship between distribution and resistance of class Ⅰ integron in 88 strains of K pneumoniae

目的:研究Ⅰ类整合子在肺炎克雷伯菌分布、结构及其在介导耐药中的作用。方法:利用多重聚合酶链反应(PCR)方法检测整合酶基因,对其阳性菌株可变区扩增产物进行测序分析;采用微量稀释法测定14种抗生素对试验菌株的敏感性。结果:在其中38株肺炎克雷伯菌DNA上检测到I类整合,阳性率43.2%。所携带的耐药基因盒绝大多数为aadA2和dfr17,整合子阳性组耐药率明显高于阴性组(P<0.05)。结论:目前临床分离的肺炎克雷伯菌耐药性强,并广泛存在I类整合子。菌株携带基因盒和耐药表型之间有较好的对应关系,基因盒介导了细菌耐药性。耐药基因盒是整合子阳性菌株对氨基糖苷类耐药的主要原因。

Objective：To investigate the distribution, structure and inducing drug resistance of the class I integron on Kpneumoniae. Methods： PCR method was used to detect integrase gene（intI） and product of variable region of positive strain was performed on sequencing. Sensitivity of experimental strains to 14 kinds of antibiotics was detected with microdilution method. Results： IntI was identified in plasmid DNA of 38 strains of Kpneumoniae （43.2%）. The most drug resistance gene cassettes were aadA2 and dfrl7. The drug resistance of integron positive groups was significantly higher than that of negative groups. Conclusion： Class I integrons existed in K pneumoniae widely. There has preferably relationhip between strains with gene cassettes and drug resistance phenotype. Gene cassettes mediate bacterial drug resistance. The main cause of drug resistance of integron positive strain to aminoglycosides sulfonamides is drug resistance gene cassettes.