Amat S, Subramanian S, Timsit E, Alexander T W
Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.
Lett Appl Microbiol. 2017 May;64(5):343-349. doi: 10.1111/lam.12723.
This study evaluated the potential of probiotic bacteria to inhibit growth and cell adhesion of the bovine respiratory pathogen Mannheimia haemoltyica serotype 1. The inhibitory effects of nine probiotic strains (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis, Streptococcus thermophilus and two Paenibacillus polymyxa strains) against M. haemolytica were evaluated using a spot-on-lawn method. Probiotic strains were then tested for their adherence to bovine bronchial epithelial (BBE) cells and the ability to displace and compete against M. haemolytica on BBE. Except for S. thermophilus, all probiotic strains inhibited the growth of M. haemolytica, with zones of inhibition ranging between 12 and 19 mm. Lactobacillus strains and Lactococcus lactis displayed greater (P < 0·05) BBE adhesion compared with M. heamolytica (8·3%) and other probiotics (<2·2%). Strains of P. polymyxa and L. acidophilus caused the greatest reduction in M. haemolytica adherence, through both displacement and competition, compared with other probiotics. The results of this study suggest that probiotics may have the potential to colonize the bovine respiratory tract, and exert antagonistic effects against M. haemolytica serotype 1.
A common method to control bovine respiratory disease (BRD) in feedlots is through mass medication with antibiotics upon cattle entry (i.e. metaphylaxis). Increasingly, antimicrobial resistance in BRD bacterial pathogens has been observed in feedlots, which may have important implications for cattle health. In this study, probiotic strains were shown to adhere to bovine respiratory cells and inhibit the BRD pathogen M. haemolytica serotype 1 through competition and displacement. Probiotics may therefore offer a mitigation strategy to reduce BRD bacterial pathogens, in place of metaphylactic antimicrobials.
本研究评估了益生菌抑制牛呼吸道病原体溶血曼氏杆菌1型生长和细胞黏附的潜力。使用点种法评估了9种益生菌菌株（嗜酸乳杆菌、干酪乳杆菌、瑞士乳杆菌、植物乳杆菌、鼠李糖乳杆菌、乳酸乳球菌、嗜热链球菌和两株多粘芽孢杆菌）对溶血曼氏杆菌的抑制作用。随后测试了益生菌菌株对牛支气管上皮（BBE）细胞的黏附能力，以及在BBE细胞上取代和竞争溶血曼氏杆菌的能力。除嗜热链球菌外，所有益生菌菌株均抑制了溶血曼氏杆菌的生长，抑菌圈直径在12至19毫米之间。与溶血曼氏杆菌（8.3%）和其他益生菌（<2.2%）相比，乳杆菌属菌株和乳酸乳球菌对BBE细胞的黏附性更强（P<0.05）。与其他益生菌相比，多粘芽孢杆菌和嗜酸乳杆菌菌株通过取代和竞争作用，最大程度地降低了溶血曼氏杆菌的黏附。本研究结果表明，益生菌可能有定殖于牛呼吸道并对溶血曼氏杆菌1型发挥拮抗作用的潜力。
在饲养场控制牛呼吸道疾病（BRD）的常用方法是在牛入场时通过大量使用抗生素进行预防性投药（即群体预防）。在饲养场中，越来越多地观察到BRD细菌病原体出现抗菌药物耐药性，这可能对牛的健康产生重要影响。在本研究中，益生菌菌株显示出能黏附于牛呼吸道细胞，并通过竞争和取代作用抑制BRD病原体溶血曼氏杆菌1型。因此，益生菌可能提供一种替代预防性抗菌药物的策略，以减少BRD细菌病原体。
