铜绿假单胞菌整合子分布差异与耐药性的关系

The relationship between the integrons distribution and drug resistance of Pseudomonas aeruginesa

目的通过调查临床分离的铜绿假单胞菌(PA)的耐药特征及整合子分布差异,并检测整合子中耐药基因盒信息,以探讨整合子携带与细菌耐药的关系。方法收集临床分离的非重复PA共68株;采用BDphoenix100全自动细菌鉴定仪进行细菌鉴定和药敏试验;采用聚合酶链式反应(PCR)和琼脂糖凝胶电泳方法对Ⅰ类、Ⅱ类和Ⅲ类整合子及可变区进行检测,并对可变区阳性标本进行测序分析。结果41株碳青酶烯类敏感菌株Ⅰ类、Ⅱ类和Ⅲ类整合子均未检出;27株碳青酶烯类耐药菌株Ⅰ类整合子的检出率为25.9%(7/27),未检出Ⅱ类、Ⅲ类整合子;7株Ⅰ类整合子阳性菌株中有6株成功扩增出可变区,可变区扩增阳性率为85.7%(6/7),其携带耐药基因盒包括ant(2″)-Ⅰa、aadA1、aadA4、aadB、aadA2、aadA15、blaVIM-2、blaVIM-3、blaOXA-2、arr-6、qnrVC1、cmlA15共12种,检出的耐药基因盒与耐药表型有较好的一致性。结论Ⅰ类整合子是介导PA耐药的重要因素之一,在耐药基因传播中可能起着关键作用。

Objective To investigate the drug resistance characteristics and the integrons distribution of Pseudomonas aeruginesa(PA),and detect the information of drug resistance gene cassettes in integrons to explore the relationship between integron carrying and bacterial resistance.Methods A total of 68 strains of PA were collected.BD phoenix100 automatic bacteria identification instrument was used for bacterial identification and drug susceptibility testing.The methods of PCR and agarose gel electrophoresis were used to detect integrons and its variable regions,and the variable regions were sequenced.Results No classⅠ,ⅡandⅢintegrons were detected in 41 strains of carbapenem-sensitive strains;The detection rate of classⅠintegrons of 27 strains of carbapenem-resistant strains was 25.9%(7/27),classⅡand classⅢintegrons were not detected;6 of the 7 strains of classⅠintegron positive strains successfully amplified the variable region,and the positive rate of variable region amplification was 85.7%(6/7).The drug resistance gene cassettes carried by the 6 strains included ant(2″)-Ⅰa,aadA1,aadA4,aadB,aadA2,aadA15,blaVIM-2,blaVIM-3,blaOXA-2,arr-6,qnrVC1,and cmlA15,the drug resistance gene cassettes which were detected had a good consistency with the drug resistance phenotype.Conclusion The classⅠintegron is one of the important factors mediating drug resistance of PA and it perhaps plays an important role in the spread of drug resistance gene,which should be paid sufficient attention.