Microbiology and Fermentation Technology Department, CSIR-Central Food Technological Research Institute, Mysore 570 020, India.
Microbiology and Fermentation Technology Department, CSIR-Central Food Technological Research Institute, Mysore 570 020, India.
Food Res Int. 2019 Feb;116:1066-1075. doi: 10.1016/j.foodres.2018.09.046. Epub 2018 Sep 20.
Three strains of Lactobacillus comprising Lactobacillus salivarius (CHS-1E and CH7-1E) and Lactobacillus reuteri (CH2-2) previously isolated from chicken meat were analyzed for their transferability of antibiotic resistance (AR) genes to pathogenic strains under in vivo, in vitro, and during food fermentation. For in vivo model, Albino Wistar rats were inoculated with 10 CFU/g/ml of Enterococcus faecalis JH2-2 (recipient). After 7 days, either of two donors L. salivarius CH7-1E or L. reuteri [harbouring erythromycin and tetracycline resistance genes] were introduced at a concentration of 10 CFU/ml daily for 1 week. Two days after donor introduction, there was a stable increase in the number of transconjugants in the animal faeces from 10 to 10 CFU/g and presented erm(B), tet(M), tet(L) and tet(W) in their genome like donor strains. Similar observations were made with in vitro filter mating between CHS-1E, CH2-2 and CH7-1E and E. faecalis JH2-2 with transfer frequencies of 1 × 10, 3.8 × 10 and 2 × 10 per donor cell respectively. With the results obtained in vivo and in vitro, the AR transferability of donor strains was estimated during food fermentation (chicken sausage, fermented milk or idli batter) with pathogenic recipient strains added as contaminants. At the end of mating period, phenotypic resistance to erythromycin and tetracycline in Listeria monocytogenes and Yersinia enterocolitica strains was observed. This study showed the ability of food borne Lactobacillus in diffusing their AR traits in diverse natural environments increasing their concern of AR dissemination in the food chain when used as food additives and/or probiotics.
先前从鸡肉中分离出的三株乳酸菌，包括唾液乳杆菌（CHS-1E 和 CH7-1E）和罗伊氏乳杆菌（CH2-2），对其在体内、体外和食品发酵过程中向致病菌传递抗生素耐药性（AR）基因的能力进行了分析。在体内模型中，用 10ⁿ CFU/g/ml 的粪肠球菌 JH2-2（受体）接种白化 Wistar 大鼠。7 天后，以 10ⁿ CFU/ml 的浓度每天引入两种供体中的一种，即唾液乳杆菌 CH7-1E 或罗伊氏乳杆菌[携带红霉素和四环素耐药基因]，持续 1 周。供体引入两天后，动物粪便中转基因的数量从 10 增加到 10ⁿ CFU/g，其基因组中呈现出供体菌株的 erm(B)、tet(M)、tet(L)和 tet(W)。在 CHS-1E、CH2-2 和 CH7-1E 与粪肠球菌 JH2-2 之间进行体外滤膜交配时也观察到了类似的现象，其转移频率分别为 1×10、3.8×10 和 2×10 个供体细胞。根据体内和体外的结果，在添加致病菌作为污染物的食品发酵（鸡肉香肠、发酵乳或 idli 面糊）过程中估计了供体菌株的 AR 可转移性。在交配期结束时，观察到单核细胞增生李斯特菌和小肠结肠炎耶尔森氏菌对红霉素和四环素的表型耐药性。这项研究表明，食源乳酸菌有能力在不同的自然环境中扩散其 AR 特性，当它们作为食品添加剂和/或益生菌使用时，增加了它们在食物链中传播 AR 的关注。
