食品科学

• 生物工程 • 上一篇    下一篇

食源性乳杆菌中耐药基因的转移研究

马沁沁1,2,付 雨1,孙 群1,*   

  1. 1.四川大学生命科学学院,生物资源与生态环境教育部重点实验室,四川 成都 610064;
    2.四川师范大学生命科学学院,四川 成都 610101
  • 出版日期:2015-12-15 发布日期:2015-12-24

Antimicrobial Resistant Gene Transfer of Foodborne Lactobacilli

MA Qinqin1,2, FU Yu1, SUN Qun1,*   

  1. 1. Key Laboratory of Bio-resource and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China; 2. College of Life Sciences, Sichuan Normal University, Chengdu 610101, China
  • Online:2015-12-15 Published:2015-12-24

摘要:

为评估食品中乳杆菌(Lactobacillus spp.)耐药基因转移所引起的食品安全风险,对耐药乳杆菌菌株进行了红霉素、万古霉素和氟喹诺酮类药物耐药基因的聚合酶链式反应(polymerase chain reaction,PCR)检测,植物乳杆菌(Lactobacillus plantarum)、嗜酸乳杆菌(Lactobacillus acidophilus)和德氏乳杆菌(Lactobacillusdelbrueckii)中检测到红霉素耐药基因msrC,万古霉素和氟喹诺酮类药物耐药基因检测结果为阴性。以供体菌和受体菌菌液体积比为10∶1,通过滤膜杂交法,进行乳杆菌耐药基因msrC对金黄色葡萄球菌(Staphylococcus aureus)的体外转移,但仅获得1 个接合子菌落;乳杆菌对粪肠球菌(Enterococcus faecalis)msrC基因体外转移频率约为2.2×10-2,与敏感菌相比,接合子生长速率减缓。在无特定病原体(specific pathogen free,SPF)裸鼠肠道内进行的L. delbrueckii对E. faecalis的msrC基因体内转移中未检测到接合子。结果表明,乳杆菌携带的可转移耐药基因在肠道内传递至致病菌或机会致病菌的机率很小,且接合子生长比敏感菌缓慢,在抗生素选择压降低或消失的条件下易被淘汰。因此,目前食源性乳杆菌中耐药基因可能引起的食品安全风险较小。

关键词: 耐药性, 乳杆菌, 基因转移, 接合子, 食品安全

Abstract:

To assess the risk of antimicrobial resistant gene transfer from foodborne Lactobacillus strains to human
pathogens or opportunistic pathogens, we performed the detection of the resistant genes of erythromycin, vancomycin
and fluoroquinolones in resistant Lactobacillus strains. Erythromycin resistant gene msrC was shown in the plasmids
of Lactobacillus plantarum, Lactobacillus acidophilus and Lactobacillus delbrueckii, while negative results were
obtained for vancomycin and fluoroquinol ones. Filter mating was carried out at a donor/recipient ratio of 10:1 with
Staphylococcus aureus and E. faecalis as the recipients and L. delbrueckii the donors, respectively. In L. delbrueckii and
S. aureus mating pair, only one exconjugant was obtained, and the average gene transfer frequency of L. delbrueckii to
E. faecalis was 2.2 × 10-2, indicating that the mobile resistant gene from lactobacilli could disseminate to pathogens. The
growth rate of exconjugants was lower than the control, so exconjugants might be washed out more easily than their
susceptible counterpart when antimicrobial selective pressure was absent. The transfer of msrC from L. delbrueckii to
E. faecalis was not observed in gnotobiotic rats. Accordingly, lactobacilli widely used in foods now may not increase the
antimicrobial resistance in pathogens, thus threatening public health severely.

Key words: antimicrobial resistance, Lactobacillus, gene transfer, exconjugant, food safety

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