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目的研究食品中大肠埃希菌的整合子携带情况及其与耐药性之间的关系。方法PCR检测细菌总DNA中1、2、3类整合酶基因,确定细菌携带整合子的情况。阳性菌株进一步检测整合子的可变区,分析插入基因盒的序列。结果50株大肠杆菌中19株携带1类整合子, 2株携带2类整合子,集中分布在对4种以上抗生素耐药的菌株中。插入基因盒主要是dfr和aadA类基因盒,各种基因盒组合中最常见的是dfr17-aadA5。结论细菌的多重耐药性与整合子携带高度一致,但是单个菌株的耐药谱与整合子的耐药基因盒缺乏对应关系。
Objective To study the integration of Escherichia coli in food and its relationship with drug resistance. Methods The genotypes 1, 2, and 3 of bacterial total DNA were detected by polymerase chain reaction (PCR) to determine the status of bacteria carrying integron. Positive strains further test the variable region of the integron and analyze the sequence inserted into the gene cassette. Results Of the 50 E. coli strains, 19 strains carried type 1 integrons and 2 strains carried 2 types of integrons, which were concentrated in more than 4 antibiotic-resistant strains. The insert gene cassettes are predominantly the dfr and aadA gene cassettes and the most common of the various gene cassette combinations is dfr17-aadA5. Conclusion The multi-drug resistance of bacteria is highly consistent with that of integron. However, there is a lack of correspondence between the drug resistance spectrum of single strain and the resistant gene cassette of integron.