肺炎克雷伯菌整合子分布与耐药性关系

摘要

Objective To investigate the distribution of I, II, III integrons in ESBL-producing and non-ESBL-producing Klebsiella pneumonia (KP), exploring the relationship between the drug resistance characteristics and the integrons in our hospital.Methods 30 strains of KP producing ESBLs and 50 strains of non-ESBLs KP were isolated and preserved from clinical specimens.The BD phoenix100 automatic bacteria identification instrument was used for identification and drug susceptibility testing;integrons and variable regions were detected using Polymerase Chain Reaction (PCR) and agarose gel electrophoresis, and variable region were sequenced to clarify the context of gene cassette.Results 30 strains of classs 1 integron-positive strains were detected in 80 strains of KP;among them, the detection rate of that in ESBL-producing strains was 73.3％ (22/30);which in non-ESBL-producing strains was 16％ (8/50);and no classⅡandⅢintegrons was detected.The variable regions were successfully amplified in 8 strains for classs I integronpositive and 10 drug-resistant gene boxes including dfrA1, dfrA12, dfrA17, dfrA25, AaadA1, aadA2, aadA5, orfC, orfF and cmlA1 were found.There's some correlation between the gene cassette carried by ingegron with the resistance phenotype.Conclusion The distribution of class I integrons in ESBL and non-ESBL-producing KP is significant.The difference showed that it is closely related to the resistance, which should be paid enough attention.%目的 通过调查Ⅰ、Ⅱ、Ⅲ类整合子在临床分离产ESBL与非产ESBL肺炎克雷伯菌中的分布情况,分析其与细菌耐药性关系.方法 收集并保存临床送检标本分离出的产ESBLs肺炎克雷伯菌30株,非产ESBLs肺炎克雷伯菌50株;采用BD phoenix100全自动细菌鉴定仪进行鉴定及药敏试验;整合子及可变区测定采用聚合酶链式反应(PCR)扩增和琼脂糖凝胶电泳,并对可变区阳性菌株进行测序分析.结果 80株肺炎克雷伯菌中检测出整合子Ⅰ阳性菌株共30株;其中,在产ESBL菌株中检出率为73.3％(22/30);非产ESBL肺炎克雷伯菌中检出率为16％(8/50);未检出Ⅱ类及Ⅲ类整合子.有8株成功扩增出可变区,检出dfrA1,dfrA12,dfrA17,dfrA25,AaadA1,aadA2,aadA5,orfC,orfF,cmlA1共10种耐药基因盒,与耐药表型有一定的相关性.结论 I类整合子在ESBL和非产ESBL的肺炎克雷伯菌中的分布存在明显差异,显示其与细菌耐药性关系密切,应予以足够重视.