2012 Annual Report
1a.Objectives (from AD-416):
Objective 1: Investigate the use of non-antibiotic compounds as potential intervention/control strategies to reduce the colonization of foodborne pathogens, especially Salmonella and Campylobacter, in poultry. Determine the impact of this intervention on the prevalence of antibiotic-resistant pathogens.
Sub-objective 1A: Reduce the incidence of Campylobacter in poultry utilizing a motility enhanced probiotic.
Sub-objective 1B: Reduce the incidence of Salmonella and Campylobacter in poultry utilizing caprylic acid.
Sub-objective 1C: Reduce the incidence of Salmonella and Campylobacter in turkeys utilizing natural plant extracts trans-cinnamaldehyde, eugenol, thymol, and proanthocyanidins.
Sub-objective 1D: Reduce the incidence of Salmonella and Campylobacter in turkeys utilizing combinations of caprylic acid and natural plant extracts trans-cinnamaldehyde, eugenol, thymol, and proanthocyanidins.
Objective 2: Determine the role of stress-related factors in the emergence and persistence of foodborne pathogens in poultry from farm to processing, and develop non-antibiotic feed ingredients or other potential interventions for decreasing the impact of those risk factors on pathogen colonization and prevalence in turkeys.
Sub-objective 2A: Determine effects of the host stress response on colonization sites and pathogenicity of Escherichia coli in genetic lines of Japanese quail, and determine if heat stress or line affects pathogen virulence and colonization of Salmonella.
Sub-objective 2B: Determine effects of the host stress response and heat stress/E. coli challenge on colonization sites and pathogenicity of C. coli in genetic lines of Japanese quail, and determine if heat stress/E. coli challenge affects colonization patterns of Campylobacter.
Sub-objective 2C: Determine effects of E. coli challenge and transport stress on colonization sites of C. coli in selected genetic lines of the turkey host.
Sub-objective 2D: Develop nonspecific immunomodulators as alternative feed or water ingredients to improve the Japanese quail and turkey stress response, thus decreasing pathogen colonization of commercial turkeys.
1b.Approach (from AD-416):
The goal of this project is to develop novel, non-antibiotic intervention strategies to improve the safety of turkey products with a special emphasis on organic production. These strategies will target both Salmonella and Campylobacter and will include novel motility enhanced probiotics, caprylic acid, and plant-dervied essential oils to reduce colonization of these important foodborne pathogens. The project will also determine the role of production stressors on both host resistance and pathogen virulence and will explore novel plant-based feed ingredients that modulate stress effects on pathogen colonization and persistence.
We have developed a proprietary in vitro screening technique for rigorous selection of poultry bacterial isolates based on motility and flagella characteristics with anti-Campylobacter properties. Our strategy for developing an effective competitive exclusion culture against Campylobacter is to use motility-enhanced bacteria having the marked capability to exclude Campylobacter because of their ability to reach the same environmental niche in the intestinal crypts of poultry species. Selected motile strains were tested for anti-Campylobacter properties, with five out of six able to inhibit Campylobacter growth in vitro. Our studies indicate that the motility enhancement passes improved abilities of these bacteria for competing with Campylobacter, and may provide a strategy for reducing the pathogen in pre-harvest poultry.
We continue developing strategies for organic poultry production that can reduce pathogens, focusing on natural antimicrobials, such as medium chain fatty acids and essential oils. We have developed a state-of-the-art organic/pasture poultry research facility, one of the very few organic certified poultry research facilities in the U.S. To evaluate the effect of pasture access and housing and feeding systems on the health of the birds and incidence of enteric pathogens, we are currently conducting trials at the Organic Poultry Research Facility in Fayetteville, AR. In these trials we have four treatments: permanent housing with and without access to pasture and portable pens (hoophouses) moved daily, with and without access to pasture. Each treatment had a total of 60 birds divided in 4 or 5 replicates. These studies are planned to take place at different times of the year to consider any potential seasonal effects on the pasture, birds, and enteric pathogens. We have concluded the first trial (Spring 2012) and the Summer trial is in progress.
With Industry support for feed costs we completed a 16-week turkey trial to determine if a yeast extract feed supplement would protect turkeys from the deleterious effects of transport stress and exposure to Escherichia coli. The transport/E. coli challenge significantly increased the isolation of both Salmonella and Campylobacter from the ceca by the end of the study. Both continual and intermittent yeast supplementation decreased Salmonella isolation, and intermittent supplementation tended to decrease Campylobacter isolation.
Due to the increasing costs of turkey feed we are using Japanese quail lines genetically selected for divergent corticosterone (Cort) response to restraint stress as a model system to study the impact of production stressors on pathogen colonization and to evaluate methods to decrease colonization. Two studies were completed that indicate heat stress increases isolation of Salmonella from quail ceca, and the quail line with a lower stress response had less Salmonella colonization that the line with a high stress response.
Novel probiotics target human food safety pathogens and improve poultry health. Campylobacter and Salmonella are the most commonly reported pathogens causing foodborne infections in the United States, and epidemiological evidence has implicated raw poultry products as a significant source of human infection. A novel probiotic method was developed by the Poultry Production and Product Safety Research Unit, Fayetteville, Arkansas, by selecting individual enteric bacteria capable of inhibiting growth of specific enteric pathogens in laboritory experiments. These novel probiotic cultures (composed of healthy bacteria) target Salmonella and Campylobacter in the gastrointestinal system of poultry, reducing these pathogens. This discovery was licensed to an Arkansas-based start-up company in cooperation with the University of Arkansas. The commercial product (FloraMax-B11) is marketed in 16 countries with approximately 300 million birds dosed per/year.
Bhaskaran, H.P., Donoghue, A.M., Arsi, K., Wooming, A., Reyes-Herrera, I., Bielke, L.R., Tellez, G., Byrd II, J.A., Blore, P.J., Hargis, B.M., Donoghue, D.J. 2011. In vitro selection of enteric microflora for potential use as a competitive exclusion culture against Campylobacter in poultry. International Journal of Poultry Science. 10(12):940-945.