Department of Food Science and Biotechnology, Kyonggi University, Suwon 16227, Republic of Korea.
Division of Sports Science, Kyonggi University, Suwon 16227, Republic of Korea.
FEMS Microbiol Lett. 2022 Mar 11;369(1). doi: 10.1093/femsle/fnac017.
We evaluated the antibiotic minimum inhibitory concentrations (MICs) of 123 Bacillus velezensis strains predominantly isolated from fermented soybean foods from Korea. When the 2018 European Food Safety Authority breakpoint values for Bacillus spp. were applied, all the strains were sensitive to chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, tetracycline and vancomycin, and eight strains (6.5%) were resistant to streptomycin. The population distribution in MIC tests with streptomycin was continuous and the profile was clearly different from that expected for acquired antibiotic resistance. As of 25 October 2021, there were 181 complete published genomes of B. velezensis strains; 175 (96.7%) and 136 (75.2%) of these strains, respectively, possess potential tetracycline and streptomycin resistance genes tetL and ant(6) in the chromosome. In Bacillus licheniformis, SpeG confers resistance to clindamycin and there is an 'speG' gene annotated in the genomes of 180 B. velezensis strains; however, the gene products exhibit ≤26.6% amino acid identity with that from B. licheniformis DSM 13T. All the potential antibiotic resistance genes in the 181 B. velezensis strains were intrinsic, and traits of lateral gene transfer were not found. In this context, B. velezensis may not present a high risk in terms of antibiotic resistance in food fermentation or human use.
我们评估了主要从韩国发酵大豆食品中分离的 123 株枯草芽孢杆菌的抗生素最小抑菌浓度 (MIC)。当应用 2018 年欧洲食品安全局对芽孢杆菌属的断点值时，所有菌株均对氯霉素、克林霉素、红霉素、庆大霉素、卡那霉素、四环素和万古霉素敏感，8 株（6.5%）对链霉素耐药。MIC 试验中链霉素的种群分布是连续的，其分布特征与获得性抗生素耐药性明显不同。截至 2021 年 10 月 25 日，已公布的枯草芽孢杆菌完整基因组有 181 个；其中 175 个（96.7%）和 136 个（75.2%）分别在染色体上携带潜在的四环素和链霉素抗性基因 tetL 和 ant(6)。在地衣芽孢杆菌中，SpeG 赋予克林霉素抗性，在 180 株枯草芽孢杆菌基因组中注释有“speG”基因；然而，基因产物与来自地衣芽孢杆菌 DSM 13T 的产物的氨基酸同一性小于等于 26.6%。181 株枯草芽孢杆菌中的所有潜在抗生素抗性基因均为固有基因，未发现水平基因转移的特征。在这种情况下，枯草芽孢杆菌在食品发酵或人类使用中可能不会表现出很高的抗生素耐药性风险。
