Campylobacter jejuni is the leading cause of bacterial foodborne illness in North America. Contaminated poultry are the primary risk factor for C. jejuni infection in humans. Thus, reducing the levels of C. jejuni colonization in poultry is a priority in the area of risk management and control to increase food safety.
Supplementation of poultry feed with the high-efficiency feed supplement, xylanase, was demonstrated to cause changes in mucin carbohydrates and reduce mucin viscosity and C. jejuni colonization. In order to further exploit this finding, we will investigate the role of chicken mucin viscosity and carbohydrate content on C. jejuni virulence and colonization potential. In addition, NRC-IBS has engineered a superior xylanase supplement (http://ibs-isb.nrc-cnrc.gc.ca/ibs/ourstories/iogenstory_e.html) that is able to resist extreme temperatures during animal feed pelleting and remains active in the chicken gastrointestinal tract. Together we will compare the effects of commercial and NRC-IBS modified xylanase on C. jejuni colonization with the intent to develop a cost-effective high efficiency animal feed supplement that will also improve Ontario Food Safety by reducing the levels of C. jejuni colonization in poultry. This objective will be achieved through the efforts of our group with internationally recognized expertise in the analyses of colonization factors (Szymanski/Allan), development of animal models (Allan/Bihun), carbohydrate structure elucidation (Brisson/Kelly), gene expression profiling (Nash) and xylanase engineering (Sung). These studies will involve using well developed in vivo model systems, state-of-the art analytical equipment available at NRC-IBS (http://ibs-isb.nrc-cnrc.gc.ca/ibs/immunochemistry/bioanalysis_e.html) and in-house developed C. jejuni microarrays (http://ibs-isb.nrc-cnrc.gc.ca/ibs/immunochemistry/campychips_e.html).
Expected Impact of Project Outcomes on Food Safety in Ontario:
C. jejuni is the leading cause of gastroenteritis in Canada resulting in a significant health burden to our economy. The primary risk factor for campylobacter infection is contaminated poultry. Recently it has been demonstrated that supplementation of chicken feed with xylanase causes a decrease in C. jejuni colonization with a simultaneous change in mucin viscosity and carbohydrate content . Other studies have demonstrated that both the physical changes in viscosity and the presence of mucin have affects on C. jejuni infectivity (2,3), Bourke, personal communication). We will further extend these observations by using our expertise in carbohydrates and understanding of C. jejuni regulatory pathways, to examine the xylanase induced changes in mucin and how this influences campylobacter colonization of poultry. In addition, chicken feed will be supplemented with commercial xylanase and compared with an NRC-IBS modified xylanase to determine reduction of campylobacter colonization. With Iogen Corporation (Ottawa), the NRC-IBS enzyme has been engineered to resist extreme temperatures during animal feed pelleting, remains active in the chicken gastrointestinal tract, and facilitates efficient feed conversion through better digestion and assimilation, leading to enhanced meat and egg production. Thus, the modified xylanases, currently approved for use in pulp bleaching with annual sales in the millions, have further applications in food safety and the livestock industry. <P> For more information, please visit the <a href="http://www.omafra.gov.on.ca/english/research/foodsafety/index.html" target="_blank">Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA) Food Safety Research Program</a>.