市售发酵食品中乳酸菌的耐药性评估及传播风险研究

Antibiotics Resistance Evaluation and Transmission Risk of Lactic Acid Bacteria in Commercial Fermented Foods

为评估发酵食品中乳酸菌的耐药性及其传播风险,作者对市售酸奶和泡菜中的乳酸菌进行分离鉴定。以纸片扩散法鉴定其耐药表型,分析多重耐药情况,PCR鉴定其耐药基因型。从40份样品中共分离得到包括9种不同种属在内的62株乳酸菌,其中酸奶源乳酸菌均为多重耐药菌,对卡那霉素等5种抗生素的耐药率均高于泡菜源菌株,而泡菜源乳酸菌对庆大霉素和链霉素的耐药率均在40%以上。耐药基因型鉴定结果表明,tetM的检出率最高,为16.12%,酸奶样品分离株中有5种基因的检出率高于泡菜样品。2株酸奶源菌株中四环素耐药基因tetM可通过质粒接合作用转移到受体菌EC600中。作者对市售发酵食品乳酸菌进行了耐药性评估与传播风险研究,为保障发酵食品安全提供理论依据。

To evaluate the antibiotic resistance of lactic acid bacteria in fermented foods and their transmission risk,this study was conducted to isolate and identify lactic acid bacteria from commercially available yogurt and kimchi,to identify their antibiotic resistance phenotypes by disk diffusion method,to analyze multi-antibiotic resistance,and to identify their antibiotic resistance genotypes by PCR.A total of 62 strains of lactic acid bacteria including 9 different species were isolated from 40 samples.Most of the strains were multi-antibiotic resistant from the yogurt origin.The resistance rates of yogurt-derived Lactobacillus to five antibiotics,including kanamycin,were higher than those of kimchi-derived strains,while the resistance rates of kimchi-derived Lactobacillus to gentamicin and streptomycin were above 40%.The results of antibiotic-resistant genotype identification showed the detection rate of tetM gene was the highest at 16.12%.The detection rates of fivegenes in yogurt sample isolates were higher than kimchi samples.The results of plasmid conjugation transfer showed that the tetracycline resistance gene tetM could be transferred to the recipient bacterium EC600 from two yogurt-derived strains.Overall,this study was conducted to assess the antibiotic resistance and transmission risk of lactic acid bacteria in commercially available fermented food,it can provide theoretical basis for ensuring the safety of fermented food.