产金属酶铜绿假单胞菌携带Ⅰ类整合子的研究

Analysis of class Ⅰ integrons in metalloenzyme-producing Pseudomonas aeruginosa

目的研究产金属酶铜绿假单胞菌携带Ⅰ类整合子及其基因盒的情况。方法收集铜绿假单胞菌68临床株,进行金属酶IMP-1、VIM基因的PCR检测,选取阳性株再作第Ⅰ类整合酶基因的PCR检测,然后选取整合酶基因阳性株进行Ⅰ类整合子相关基因盒的PCR检测。结果PCR检测出68株铜绿假单胞菌中的1株同时含有IMP-1基因和Ⅰ类整合子基因盒;55株含有VIM基因,其中26株含有Ⅰ类整合酶基因,在这26株中只有18株含有Ⅰ类整合子基因盒,根据电泳条带可分为5种类别。结论首次在中国西南地区发现产IMP-1并同时带有Ⅰ类整合子的铜绿假单胞菌。Ⅰ类整合子在产金属酶铜绿假单胞菌中分布广泛,基因盒携带率为69.2%,对细菌的耐药性传播具有重要意义。

Objective To investigate class Ⅰ integrons and integrated gene cassettes in metalloenzyme-producing Pseudomonas aeruginosa. Methods A total of 68 isolated clinical strains ofPseudomonas aeruginosa were subjected to PCR analysis with primers specific for blaIMP-1 and blaVIM. The positive strains then underwent examination for class Ⅰ integrons and integrated gene cassettes with PCR with primers specific to class Ⅰ integrase （IntI1） and integrated gene cassettes, followed by sequence analysis for some of the positive strains. Results Only 1 isolated strain showed positive results for both blaIMP-1 and blaIntI1 detection. Fifty-five strains were positive for blaVIM, including 26 positive for blaIntI1. Of the 26 blaIntI1-positive strains, only 18 contained integrated gene cassettes, which were classified into 5 types according to agarose gel electrophoresis. Conclusion It is the first time to identify IMP-1-producing Pseudomonas aeruginosa carting blaInt1 in West China. The class Ⅰ integrons were widespread in these Pseudornonas aeruginosa and 69.2% of them carry the gene cassettes. These findings provide useful insights into the clinical spread of these drug-resistant genes.