Project Number: 3625-32000-080-00
Project Type: Appropriated

Start Date: Feb 17, 2006
End Date: Feb 16, 2011

Objective:
(1) Using optimized sampling strategies, enumeration, and molecular diagnostic, identify management practices resulting in high and low Salmonella and Campylobacter prevalence turkey farms and monitor the efficacy of on-farm intervention strategies targeting specific risk factors. (2) Identify key virulence attributes to differentiate Salmonella and Campylobacter avirulent commensals from those pathogenic strains that pose a public health threat in humans. (3) Develop molecular methods to assess the dynamics of the microbial intestinal flora throughout hog and turkey production. Identify microbes associated with gut colonization by, and population shifts of, foodborne pathogens. (4) Determine prevalence and quantities of recognized foodborne pathogens, principally Salmonella but also Campylobacter and Yersinia, in hog carcasses and organs.

Approach:
Time of entry of Salmonella and Campylobacter will be monitored in turkeys. The study will document flock management practices which affect the prevalence of these foodborne pathogens initially in the brooder period and ultimately throughout live production. Key virulence attributes of C. jejuni and C. coli strains recovered from turkeys will be characterized in vitro (cell invasion assays)and in vivo (day of hatch poult model.) Ultimately, differential gene expression formats will be used to differentiate a virulent from virulent isolates of C. coli and C. jejuni. Bacterial and fungal communities of the ceca of domestic and wild turkeys will be described. This initial survey will provide a measurement of diversity between wild and domestic birds. Analysis of total community flux over time will focus on kinetics of Campylobacter community development and stability in the turkey ceca. Organisms that correlate with Campylobacter colonization or exclusion will be identified. Second generation PCR assays will be developed to detect and quantify Salmonella and Campylobacter on hog and turkey carcasses. Monitoring viscera will serve as an indicator of on-farm versus in-plant sources of contamination. These studies will assist in determining the critical control points of contamination during slaughter. IBC-0281R BSL-2/BSL2N; Recertified 6/13/08; IBC 0307 Certified 06/11/08; IBC 0308 Certified 06/11/08.