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.
3. Progress Report:
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. As part of this work we evaluated the potential of cranberry proanthocyanidins to reduce Campylobacter in vitro and after colonization in poultry. Extracts from American Cranberry (Vaccinium macrocarpon) contain proanthocyanidins which have antimicrobial activity against other foodborne pathogens, including E. coli and Salmonella, but their activity against Campylobacter was unknown. The study objective was to evaluate, in vitro and in vivo, the efficacy of cranberry proanthocyanidins. In replicate in vitro trials, the lowest concentrations of cranberry proanthocyanidins did not reduce Campylobacter. A 1–5 log reduction at 1% (wt/vol) was observed, and at 2 or 4% (wt/vol) there was a minimum 5 log reduction in Campylobacter. For in vivo studies, birds (n=10/treatment) were given cranberry proanthocyanidins at concentrations of 0.5%, 1%, or 2% (wt/wt) supplemented in the feed starting at day of hatch and continuing through day 14. In trials, cecal Campylobacter counts were not reduced. Although highly effective in vitro, more evaluation is needed to determine optimum concentrations of cranberry proanthocyanidins to reduce Campylobacter in poultry. We continue research at 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, studies took place at different times of the year to consider any potential seasonal effects on the pasture, birds and enteric pathogens. We have concluded the trials and are analyzing data. We have completed 6 quail heat stress studies, including 3 that evaluated the effects of feed supplementation with Rhodiola rosea, Stresroak, or yeast extract. We reported an increased incidence in Salmonella enterica serotype Agona isolation from the ceca of quail that underwent heat stress, with birds from the low stress line having less colonization than the high stress line. We did not find any benefit of adding either R. rosea, Stresroak, or yeast extract to the feed of heat-stressed birds. We concluded that the differences that persist between the high stress and low stress quail lines will facilitate studies of the complex stress-disease interactions that plague the poultry industries. However, the stress of coming into lay appeared to confound the data for heat stress in the females, suggesting that for future studies it will be necessary to study only male birds due to the short production time available before the female birds come into lay. Continuation of the quail project will depend on the availability of enough male birds to design studies. We have therefore initiated studies using day-old chickens and turkey poults to determine the effects of adaptogens on colonization with Salmonella and Campylobacter during cold stress and Escherichia coli challenge.
1. Development of novel probiotics that target human food safety pathogens in poultry. Campylobacter is one of the most commonly reported pathogens causing foodborne infections in the United States, and raw poultry products are a significant source of human infection. An effective probiotic culture was developed using motility-enhanced bacteria having the marked capability to exclude Campylobacter because of their ability to reach the same environmental niche in the intestines of poultry. Studies in chickens indicate that selecting for motility enhancement improved abilities of these bacteria for competing with Campylobacter, and may provide a strategy for reducing the pathogen in pre-harvest poultry. A patent application on this technology has been filed.
2. A yeast culture feed supplement (YC) improves feed conversion efficiency and tends to decrease Salmonella and Campylobacter isolation. Effective replacements for the addition of growth-promoting antibiotics to turkey feed are needed primarily for their effects on feed conversion ratio (FCR). Scientists at the Poultry Production and Product Safety Research Unit, Fayetteville, Arkansas, determined that intermittent addition of YC prior to transport events significantly improved FCR of transport-stressed birds. The YC also tended to decrease cecal Salmonella and Campylobacter isolation. Because turkey feed is the overriding cost of production, the improvement in FCR may make feed supplementation with YC an economical method for increasing the safety of turkey products.
Huff, G.R., Huff, W.E., Wesley, I.V., Anthoney, N.B., Satterlee, D.G. 2013. Response of restraint stress-selected lines of Japanese quail to heat stress and Escherichia coli challenge. Poultry Science. 92(3):603-611.