临床分离阴沟肠杆菌耐药性与I类整合子关系研究

Relationship between antibiotic resistance and class I integron in Enterobacter cloacae from clinical specimens

目的了解临床分离阴沟肠杆菌整合子的分布情况,探讨I类整合子与其耐药性关系。方法收集2014年9月-2015年6月本院临床分离的阴沟肠杆菌,用Vitek2-compact全自动微生物分析仪进行细菌鉴定和大部分药敏试验,少部分采用K-B法,PCR法检测I类整合酶、基因盒。用Hinf I对基因盒的PCR产物进行酶切,相同酶切图谱随机挑取1例进行测序。结果Ⅰ类整合子检出率为54.7%(64/117)。整合子阳性菌对头孢曲松、头孢他啶、庆大霉素、阿米卡星、妥布霉素、环丙沙星、左旋氧氟沙星、复方新诺明的耐药率明显高于阴性菌,差异均有统计学意义(P<0.05)。基因盒种类以及菌株数分别为dfrA17-aadA5(26株)、aacA4-cat B8-aadA1(10株)、dfrA15-aadA2(7株)、dfrA12-orf FaadA2(6株)、aad B-aadA2(5株)、dfrA1-aadA5(4株)、cat B8-aadA1(2株)、dfrA15(2株)。结论 I类整合子在介导阴沟肠杆菌多重耐药性方面有重要作用。

Objective To investigate the distribution of class I integron in Enterobacter cloacae from clinical specimens and ex- plore the relationship between antibiotic resistance and class I integron. Methods Enterobacter cloacae were collected from September 2014 to June 2015. Vitek2 - compact was used for identification and most antimicrobial susceptibility test, and some were conducted with K - B method. Class I integrase and gene cassettes were determined by PCR. PCR products of gene cas- settes were digested with Hinf I. One representative of each restriction profile was selected for DNA sequencing. Results The detection rate of Class I integron was 54.7% （64/117）. The antibiotic resistances of integron - positive strains were higher than those of integron - negative strains generally, especially to Cefoterazone, Ceftazidime, Gentamicin, Amikacin, Tobramycin, Ciprofloxacin, Levofloxacin and Trimethoprim/sulfamethoxazote. The differences had statistical significance （ P 〈 0.05 ）. Gene cassettes were as follows： dfrA17 - aadA5 （26）, aacA4 - catB8 - aadA1 （10）, dfrAl5 - aadA2 （7）, dfrA12 - ooT - aadA2 （6）, aadB - aadA2 （ 5 ）, dfrA 1 - aadA5 （4）, catB8 - aadA 1 （2）, dfrA 15 （ 2 ）. Conclusion Class I integron plays an impor- tant oart in multi -druresistance in Enterobacter cloacae.