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Reduction of Foodborne Pathogens at Source

Investigators
Szymanski, Christine
Institutions
National Research Council - Institute for Biological Sciences (NRC-IBS)
Start date
2007
End date
2009
Objective
Contaminated poultry are an important risk factor for Campylobacter jejuni and Salmonella enterica serovar Typhimurium and Heidelberg infection in humans. NRC-IBS has engineered and patented a superior xylanase supplement that is able to resist extreme temperatures used during animal feed pelleting and remains active in the chicken gastrointestinal tract (http://ibs-isb.nrc-cnrc.gc.ca/ibs/ourstories/iogenstory_e.html). Although there have been several studies demonstrating that exogenous enzymes such as xylanase improved nutrient digestibility and broiler chicken performance, there are no studies that we noted in the literature examining the effect of xylanase supplementation on Salmonella colonization in broilers. Thus, our experiments to examine whether xylanase supplementation plays any role in S. Typhimurium and Heidelberg colonization are novel and warranted based on the preliminary data we have obtained for C. jejuni.

We have previously shown that viscosity affects C. jejuni infectivity and that supplementation of poultry feed with the high-efficiency feed supplement, xylanase, reduces C. jejuni colonization in leghorn chickens by 1-5 logs. This project aims to further investigate the role of chicken mucin viscosity and carbohydrate profiles on C. jejuni colonization. We will also extend the xylanase studies to broiler chickens and compare enzyme dose, type of feed and other strains of C. jejuni and Salmonella with the intent of developing a cost-effective animal feed supplement that also reduces foodborne pathogens at source in order to improve food safety in Ontario.

Specifically, this project aims to:

  • Assess the ability of the NRC-modified xylanase to reduce colonization of additional strains of C. jejuni and to also test S. enterica serovars Typhimurium and Heidelberg colonization in broilers;
  • Continue the mucin characterizations in order to understand the differences between chicken and human mucin and also to determine whether xylanase treatment has any effect on this innate immune mechanism which plays a key role in C. jejuni virulence; and
  • Characterize the proteome and surface carbohydrates of C. jejuni isolated directly from the broilers using immunomagnetic bead isolation and enrichment. This would be the first time anyone has looked at the protein and sugar profiles of C. jejuni directly out of birds without further subculturing and will provide information about which structures are important for C. jejuni persistence in vivo which is needed information for the development of novel therapies for the further reduction of C. jejuni at source.
More information
Expected Impact of Project Outcomes on Food Safety in Ontario: C. jejuni and S. enterica serovars Typhimurium and Heidelberg are significant causes of gastroenteritis in Canada resulting in a considerable health burden to our economy. One of the key risk factors for infection is contaminated poultry. We will expand upon the xylanase study by Fernandez et al. (Cell Mol. Life Sci. 2000) and our own studies (OMAF # FS040718) to understand the changes induced by xylanase and how they influence bacterial colonization of poultry. Our group has strong expertise in the analysis of colonization factors (Szymanski/Twine) and carbohydrates (Li), development of animal models (Szymanski) and xylanase engineering (Sung). We aim to identify the mucin and/or bacterial component responsible for reduced colonization. Chicken feed will be supplemented with commercial and NRC-modified xylanases to determine reduction of bacterial colonization and reproducibility in leghorns and broilers. Together with Iogen Corporation, the NRC 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, and recently approved for use in poultry feed by the CFIA, have applications in food safety and the livestock industry.

For more information, please visit the Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA) Food Safety Research Program.

Funding Source
Ontario Min. of Agriculture Food and Rural Affairs
Project number
SF6059
Categories
Viruses and Prions
Bacterial Pathogens
Salmonella
Commodities
Meat, Poultry, Game