Diagnostic and autologous vaccine options for porcine pathogens

在猪的生产设施中出现的挑战之一是，当细菌病原体导致严重疾病时，有传播到设施中其他动物的风险。一种常见的方法是从引起感染的细菌快速开发出一种简单的疫苗，并用这种疫苗免疫设施中的其他动物。这种“自体疫苗”方法需要快速有效地分离和鉴定引起感染的细菌，然后通过杀死细菌从整个细菌中产生安全的疫苗。这项建议旨在质疑分离和鉴定细菌并生产疫苗的标准方法是否为生产有效疫苗的最佳条件，特别是对猪病原体副猪嗜血杆菌、胸膜肺炎放线杆菌和猪链球菌。首先，我们将开发一种基于聚合酶链式反应的测试，它可以很容易地区分不同的毒株，以便我们知道是否选择了正确的毒株用于疫苗生产，或者是否涉及不止一种毒株。其次，我们计划评估疫苗生产的标准方法，看看细菌是否以最佳方式表达重要抗原，从而提供免受感染的保护。我们最近证明了这些细菌中的某些抗原，称为转铁蛋白结合蛋白(TBP)，提供了对感染的卓越保护，并能够独特地诱导对定植的保护。因此，我们建议测试生产自体疫苗的标准生长方法，看看是否有良好的TBP表达。我们将测试生长介质的各种修改，以确定符合法规要求的最佳条件。这将是一个有效的“概念验证”计划，从逻辑上讲，随后将进行一项直接测试疫苗产品的研究。识别潜在病原体和提高我们的自体疫苗效力的能力将为加拿大的畜禽生产行业提供更好的产品。这将增强他们预防毁灭性疾病的能力，并改善他们农场经营的经济效益。

One of the challenges that occur in production facilities for pigs is when a bacterial pathogen causes severe illness and there is a risk of spread to the other animals in the facility. A common approach is to rapidly develop a simple vaccine from the bacteria causing the infection and immunizing the rest of the animals in the facility with this vaccine. This 'autologous vaccine' approach requires rapid and efficient isolation and identification of the bacteria causing the infection and then generating a safe vaccine from the whole bacterium by killing the bacteria. This proposal is designed to question whether the standard approaches for isolating and identifying the bacteria and generating the vaccine are the optimal conditions for generating an effective vaccine, specifically for the pig pathogens Haemophilus parasuis, Actinobacillus pleuropneumoniae and A. suis. First of all we will develop a PCR based test that can readily distinguish different strains from one another so that we will know whether the right strain is chosen for vaccine production or whether more than one strain is involved. Secondly, we plan to evaluate the standard method of vaccine production to see whether the bacteria are optimally expressing important antigens that will provide protection from infection. We have recently demonstrated that certain antigens in these bacteria, called transferrin binding proteins (Tbps), provide superior protection against infection and are uniquely capable of inducing protection against colonization. Thus we propose to test the standard methods of growth for the production of the autologous vaccine to see whether there is good expression of Tbps. We will test various modifications of the growth media to determine the optimum conditions that meet regulatory requirements. This will effectively be a 'proof of concept' program and would logically be followed up by a subsequent study that would directly test the vaccine product. The ability to identify potential pathogenic organisms and improve the efficacy of our autogenous vaccines will provide a superior product to the livestock and poultry production industries of Canada. It will enhance their ability to prevent devastating disease and improve the economic performance of their farm operation.