关键词: 大肠杆菌; 耐药基因; 耐药质粒消除

Abstract: To preliminarily locate the resistant gene with multi-resistance in pathogenic E.coli clinically isolated from chicken and provide reasonable evidence to therapeutic treatment. The E.coli strain was isolated from liver and heart of died chicken examined. The drug resistant plasmid, extracted with plasmid extraction kit, was purified after transferred to gene engineering strain JM109. The anti-drug gene was preliminarily located through electrophoresis and drug sensitivity examination. The weeping function of the extracted material from Artemsia argyi to the resistant plasmid was tested. The results indicated that the E.coli strain with strong virulence, isolated from chicken and identified successfully, was multi-resistance to drugs, and only sensitive to fluorine spectinomycin and streptomycin. The preliminary location of anti-drugs gene, which resisted to ciprofloxacin, penicillin, ofloxacin, norfloxacin, lincomycin, and cotrimoxazole, was on the certain drug resistant plasmid. The characteristics of resistance to drug could be delivered to the gene engineering strain E.coli, in which the drug resistant plasmid extracted was transferred to. Boiled leaves solution can eliminate 60% the bacteria resistance plasmid. Susceptibility test results showed that the bacteria eliminated resistant plasmids restored sensitivity to ciprofloxacin, penicillin, ofloxacin, norfloxacin, lincomycin and cotrimoxazole. Therefore, the anti-drug genes were located on plasmid and chromosome of the isolated strain. The extracted material from leaves had strong weeping function, and could be used as clinical therapeutic medicine.

Key words: Escherichia coli; drug-resistance genes; antibiotic plasmid elimination