Diagnostic and autologous vaccine options for porcine pathogens

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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.