Biosecurity and Diversity of Foodborne Pathogen Populations on Poultry Farms

NON-TECHNICAL SUMMARY: Campylobacter jejuni, Listeria monocytogens, and Salmonella spp. are among the leading foodborne bacterial pathogens in the USA. Poultry products are a major source of these organisms. Assess the prevalence of these foodborne pathogens in commercial chicken and turkey production.Sampling will occur on selected breeder farms and hatcheries to assess the relative importance of these sources of transmission.

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APPROACH: Campylobacter jejuni, Listeria monocytogenes, and Salmonella spp. are among the leading foodborne bacterial pathogens in the USA . Poultry products are a major source of these organisms. Using epidemiological study designs, the prevalence of these foodborne pathogens will be assessed in commercial chicken and turkey operations. The population diversity of each pathogen will be determined on farms, after transportation to the abattoir, and at the end of the processing line. Sampling will also occur on selected breeder farms and hatcheries in an effort to assess the relative importance of these sources of transmission. In addition, sampling will be done on vectors such as arthropods, rodents, and feed; as well as other poultry houses, and non-poultry farms (swine and cattle) found in proximity to the study farms. These study farms will be surveyed in order to determine management and environmental risk factors that may be associated with foodborne pathogens. A prospective study will allow us to assess the impact of a biosecurity extension program on foodborne pathogens at the farm. Results from these studies will provide us with key information to improve biosecurity and sanitation extension programs. The research findings will be integrated into educational programs, using multimedia technology. Finally, a communication network will be established for the purpose of providing access to the information by all stakeholders, in particular, those directly involved in poultry production, since they are on the front line of any foodborne pathogen reduction efforts.

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PROGRESS: 2001/09 TO 2004/09<BR>
Objectives 1 & 2: Assessment of the prevalence of leading foodborne bacterial pathogens in chicken and turkey productions, and the determination for each pathogen of its diversity on poultry farms were reported previously, except for Listeria. 35 samples (15.3% of all samples) tested positive for Listeria. Overall, only 2 samples (0.9%) tested positive for L. monocytogenes with the remaining samples containing L. innocua & L. welshimeri. Also, study of Salmonella population diversity using three different genotyping methods allowed us to show significant diversity between farms within the same geographic area but not within farm. <BR> <BR> Objective 3: Assess the relative importance of sources of transmission of these foodborne pathogens, as well as establishing the significance of close proximity of poultry and non-poultry farms: Among the 28 farms selected for the entomology study, fly traps were set inside and outside of buildings, making up 280 fly collections during the season. Total of 110,688 flies were captured for a mean fly trap capture of 404. Fly traps placed outside the poultry barn captured more flies than those inside, 65 & 45, respectively. 28 of the 274 fly pools were suspect for Salmonella on XLT medium for a total of 9.48%. Suspect cultures were subsequently not confirmed as Salmonella in AFLP analysis. <BR> <BR> Objective 4: Determine risk factors associated with foodborne pathogens: Experiment conducted to investigate the prevalence of Campylobacter jejuni in broiler chickens produced and marketed either as organic or as conventional. Prevalence ower in organic farms during winter, but not different from conventional farms on a yearly basis. No significant difference in the drug sensitivity profile of Campylobacter between these two different types of production. In order to minimize on labor costs and application time, mixtures of insecticides and disinfectants are often combined together in one spray tank for insect control and sanitization of poultry facilities. This risk factor was investigated in a controlled environment. Only two disinfectants were effective in inhibiting growth of Salmonella isolates at the prescribed label rate when mixed with an insecticide. <BR> <BR> Objective 5: Determine the impact of a biosecurity extension program on foodborne pathogens at the farm level: Extension program was designed and produced during 2002. It has been successful. Part of its success is its widespread availability, making it difficult to find a comparison group. Hence, in the summer of 2004, we elected to compare the incidence of foodborne pathogens depending on the degree of auditing of the farm's biosecurity program. Designed to also determine whether regular auditing has an impact on the degree of biosecurity compliance. <BR> <BR> Objective 6: Adjust our extension program, integrate the research findings in our educational programs, assess their value as learning tools and establish a communication network for the purpose of providing access to the information to all stakeholders: objective is still in progress, although our extension specialists in entomology have completed their component of the project.
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IMPACT: 2001/09 TO 2004/09<BR>
The extension program on biosecurity that has been created for this project is now distributed as a CD in 101 countries on all continents, with most copies found in the United States and Canada. The work comparing organic poultry production to conventional rearing suggests that organic production may not significantly alter the prevalence and drug sensitivity profile of Campylobacter isolated from carcass rinses in slaughter plants. A common practice, the mixing of insecticides with disinfectants, has been shown to significantly reduce the efficacy of most disinfectants against foodborne pathogens. One impact of this work is the current effort in other projects to review established farm management procedures not often considered as risk factors. The last component of this project is actually focusing on biosecurity compliance as a major risk factor, recognizing the importance of the degree of implementation of any given measure. Finally, the evaluation of three genotyping methods has shown that bacterial diversity is low between buildings within farms, but much higher between farms within the same geographical area. This finding has important epidemiological implications since it is telling us that bacterial population uniformity cannot be expected outside any given production facility.