A respiratory probiotic to combat infection by Actinobacillus pleuropneumoniae in the pig.

猪患有一种常见的自然疾病，传染性胸膜肺炎，由革兰氏阴性病原体胸膜肺炎杆菌(App)引起。一些猪患有严重的急性(致命)疾病，呼吸道淋巴组织中携带细菌的比例很高。饲喂抗生素和接种疫苗可以控制疾病，但不能从牛群中消除病原体。随着抗生素的使用变得越来越不被公众接受，将需要替代方法来控制牛群中的地方病。在BBSRC资助的App毒力遗传学研究中，我们已经产生了一批App突变体。在一种控制疾病和携带App的新方法中，我们将测试遗传定义的、无毒的突变株，以竞争性地从猪的呼吸道和淋巴组织中排除App，并占据病原体的生态位。一种专为呼吸道设计的益生菌代表了一种新的、安全的生物控制方法，旨在减少或消除猪群中的这些细菌。这一概念是控制养殖动物地方性呼吸道疾病的一种新方法，可能为逐步从国家畜群中根除这种病原体提供机会。

Pigs suffer a common, natural disease, contagious pleuropneumonia, due to the Gram-negative pathogen A. pleuropneumoniae (App). Some pigs suffer severe acute (fatal) disease and a high proportion harbour the bacteria in the respiratory lymphoid tissues. In-feed antibiotics and vaccination can control the disease but do not remove the pathogen from the herd. As antibiotic use becomes less publicly acceptable, alternative methods will be needed to control endemic disease in the herd. In BBSRC-funded research of genetics of virulence of App we have generated a number of mutants of App. In a new approach to control disease and carriage of App, we will test genetically-defined, non-virulent mutants to competitively exclude App from the respiratory tract and lymphoid tissues of the pig and occupy the ecological niche of the pathogen. A 'designer probiotic' for the respiratory tract represents a new, safe biological control method intended to reduce or eliminate these bacteria in a pig herd. This concept, a novel means of control of endemic respiratory disease in farmed animals, may offer the opportunity for a gradual eradication of this pathogen from the national herd.