Shan Qiang, Liu Ning, Wang Xue, Zhu Yaohong, Yin Jinhua, Wang Jiufeng
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
College of Animal Science and Technology, Tarim University, Alar, 843300, China.
J Anim Sci Biotechnol. 2022 Sep 9;13(1):101. doi: 10.1186/s40104-022-00752-w.
Bacillus cereus is an important pathogen that causes human food poisoning, specifically diarrhea and vomiting. B. cereus can also induce mastitis in dairy cows and has a strong survival ability in milk, as it cannot be inactivated by high-temperature short-time pasteurization. Therefore, B. cereus can enter the market through pasteurized milk and other dairy products, imposing enormous hidden dangers on food safety and human health.
In this study, B. cereus 2101 (BC) was isolated from milk samples of cows with mastitis. BC grew rapidly with strong hemolysis, making it difficult to prevent mastitis and ensure food security. MAC-T cells were treated with BC and/or Lactobacillus rhamnosus GR-1 (LGR-1). Pretreatment with LGR-1 protected the integrity of tight junctions and the expression of zonula occludens-1 (ZO-1) and occludin destroyed by BC. Furthermore, LGR-1 pretreatment reduced the expression of NOD-like receptor family member pyrin domain-containing protein 3 (NLRP3), caspase recruitment and activation domain (ASC), Caspase-1 p20, gasdermin D (GSDMD) p30, inflammatory factors (interleukin (IL)-1β and IL-18), and cell death induced by BC. Moreover, LGR-1 pretreatment reduced NLRP3 inflammasome activity and increased expressions of ZO-1 and occludin induced by lipopolysaccharides (LPS) + ATP stimulation. MAC-T cells were transfected with NLRP3 siRNA or MCC950 and/or treated with BC and/or LGR-1. NLRP3-siRNA transfection and MCC950 attenuated BC-induced NLRP3 inflammasome activity. Expression of inflammatory cytokines and cell death suggested that the inflammatory pathway might play an important role in the induction of the NLRP3 inflammasome by BC and the protection of LGR-1.
These results suggest that LGR-1 might be a probiotic alternative to antibiotics and could be administered to prevent mastitis in dairy cows, thus ensuring food security.
蜡样芽孢杆菌是一种重要的病原体，可导致人类食物中毒，尤其是腹泻和呕吐。蜡样芽孢杆菌还可诱发奶牛乳腺炎，并且在牛奶中具有很强的生存能力，因为高温短时巴氏杀菌无法将其灭活。因此，蜡样芽孢杆菌可通过巴氏杀菌牛奶和其他乳制品进入市场，给食品安全和人类健康带来巨大隐患。
在本研究中，从患乳腺炎奶牛的牛奶样本中分离出蜡样芽孢杆菌2101（BC）。BC生长迅速且溶血能力强，这使得预防乳腺炎和确保食品安全变得困难。用BC和/或鼠李糖乳杆菌GR-1（LGR-1）处理MAC-T细胞。LGR-1预处理可保护紧密连接的完整性以及被BC破坏的闭合蛋白1（ZO-1）和闭合蛋白的表达。此外，LGR-1预处理降低了NOD样受体家族含pyrin结构域蛋白3（NLRP3）、胱天蛋白酶募集和激活结构域（ASC）、胱天蛋白酶-1 p20、gasdermin D（GSDMD）p30、炎性因子（白细胞介素（IL）-1β和IL-18）的表达以及由BC诱导的细胞死亡。此外，LGR-1预处理降低了NLRP3炎性小体活性，并增加了脂多糖（LPS）+ATP刺激诱导的ZO-1和闭合蛋白的表达。用NLRP3 siRNA或MCC950转染MAC-T细胞并/或用BC和/或LGR-1处理。NLRP3-siRNA转染和MCC950减弱了BC诱导的NLRP3炎性小体活性。炎性细胞因子的表达和细胞死亡表明，炎症途径可能在BC诱导NLRP3炎性小体以及LGR-1的保护作用中发挥重要作用。
这些结果表明，LGR-1可能是抗生素的益生菌替代品，可用于预防奶牛乳腺炎，从而确保食品安全。
Zotero 插件
