Chromosome-and plasmid-mediated fluoroquinolones-resistance in Escherichia coli strains isolated from food animals and healthy people around farm
- VernacularTitle:养殖动物及人分离大肠埃希菌染色体和质粒介导氟喹诺酮耐药机制的研究
- Author:
Jingyun LI
;
Shenghui CUI
;
Yunpeng WANG
;
Changqin HU
;
Shaohong JIN
;
Yue MA
- Publication Type:Journal Article
- Keywords:
Escherichia coli;
Fluoroquinolones;
Chromosome-mediated resistance;
aac(6')-I b-cr gene
- From:
Chinese Journal of Microbiology and Immunology
2008;28(8):739-743
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study on chromosome-and plasmid-mediated fluoroquinolones-resistant in Escherichia coli isolated from fecal samples of chicken,swine and people around the farm.Methods Anti-microbial susceptibility testing was carried out by disk diffusion testing and bmth microdilution testing.gyrA,gyrB,parC,pareE,qnr and aac(6')-I b-cr were examined by PCR,and the products were sequenced.Ex-presion of aac(6')-I b-cr by conjunction was tested too.Results The resistance to antimicmbial agents was much higher in strains isolated from chicken than that from swine and human.Among the E coli strains examined by PCR,most resistant strains carried two mutations in gyrA and/or two mutations in parC.In ad-dition,some resistant strains had mutations in parE with MIC of ciprofloxacin>16μg/ml.No(resistance) mutation was found in gyrB.Seven strains(25.O%)and one strain(11.1%)had aac(6)-I b-cr,variant isolated from chicken and swine,respectively.The strains harboring cr variant enzyme reduced the suscepti-bility to ciprofloxacin and norfloxacin by N-acetylation of the drugs. Conclusion There is a close relation-ship between high level quinolone resistance and the numbers of amino acid exchange in DNA gyrase and to-poisomeraae IV,and aac(6)-I b-cr may play some role for fluoroquinolone resistance.
