Immunization of broiler chickens against necrotic enteritis

坏死性肠炎是由产气荚膜梭菌引起的肉鸡的一种重要疾病。它通常是通过使用各种抗菌药物在水中或饲料中以预防剂量给药来控制的。 然而，由于公众对在动物生产中使用抗微生物药物的关注，欧洲已禁止将抗微生物药物用于“促进生长”和疾病预防目的数年。 这种禁令可能发生在加拿大和美国。此外，许多生产者愿意饲养没有抗菌药物的动物，以获得市场优势。本实验室最近的一项研究首次表明，有可能成功地免疫肉仔鸡对抗坏死性肠炎。本研究表明，免疫力与强毒株有关，而与弱毒株无关。 我们正在开展这项工作，找出哪些蛋白质的毒力细菌作出反应的鸡已成为免疫感染或独特的毒力细菌。我们已经鉴定了大约9种蛋白质，其中三种已被表征。我们想用这些蛋白质的部分或全部以及α毒素免疫肉鸡，并确定哪些蛋白质提供针对感染的免疫力。然后，我们将开发使用这种蛋白质作为抗原，以保护鸟类免受这种严重的感染。

Necrotic enteritis is an important disease of broiler chickens caused the anaerobic bacterium Clostridium perfringens. It is usually controlled by use of various antimicrobials  administered at prophylactic doses either in water or feed.  However, because of public concern about the use of antimicrobial drugs in animal production, use of antimicrobial drugs for "growth promotional" and disease prophylactic purposes has been banned for several years in Europe.  Such a ban may occur in Canada and United States. In addition, many producers would like to rear animals without antimicrobial drugs for the market advantage this may give. Surprisingly little is known about immunity to NE.A recent study  from this laboratory showed for the first time that it is possible to immunize broiler chickens successfully against necrotic enteritis. This study showed that immunizing ability was associated with virulent but not with avirulent strains.  We are developing this work by finding out which proteins of the virulent bacteria are responded to by chickens that have become immune to infection or are unique to virulent bacteria. We have identified about 9 proteins, three of which have been characterized.We would like to immunize broiler chickens with some or all of these proteins, as well as with alpha toxin, and determine which provide immunity against infection. We will then develop the use this protein as an antigen to protect birds against this serious infection.