Project Number: 5438-42000-013-00
Project Type: Appropriated

Start Date: Apr 12, 2006
End Date: Apr 11, 2011

Objective:
1) Develop phylogenetic and phenotypic markers for E. coli O157:H7, non-O157 STEC/EHEC, and Salmonella spp. based on genomic and proteomic strain comparisons, expression analysis, and multi-drug resistance profiles for use in molecular strain typing, intervention method development, and design of multiple pathogen detection schemes. 2) Determine prevalence of unrecognized foodborne pathogens such as Shiga toxigenic E. coli on fresh imported beef to be used for ground beef and establish necessary profiling to insure imported beef products meet the same levels of safety as domestic products. 3) Identify sources of spoilage bacteria and pathogen contamination during beef transport/processing/slaughter (i.e., transport vehicles, lairage pens, air, hides, feces) and develop novel antimicrobial intervention strategies. 4) Determine the microbiological safety of lamb processed in the United States and determine the efficacy of currently used intervention technologies during various stages of lamb processing.

Approach:
Strain specific markers will be identified and will be used for tracking, typing, virulence, and detection assays. Identification of the strain specific markers will lead to a more complete understanding of bovine-related foodborne pathogen ecology in which the pathogens of concern are not the same as those of the United States. The microbial profile of ground beef imported from countries will be determined in order to establish the most effective testing guidelines. Employing traditional methodologies as well as implementing new strategies developed in Objective 1, researchers in this unit will continue longstanding efforts in tracking pathogen contamination. To better understand the contribution of feedlot settings, livestock transport, and husbandry equipment to pathogen contamination, focus will be placed on identifying surface and airborne bacterial populations associated with transport vehicles, lairage pens, and slaughter facilities. Efforts will continue in evaluating pathogen carriage on hides and in feces. New efforts will be initiated to identify sources of other pathogen and spoilage bacterial contaminants including, but not limited to, non-O157 Shiga toxin-producing E. coli (STEC), Salmonella spp. and Clostridium spp. As new sources of pathogen contamination are identified, research will be undertaken to develop and evaluate novel antimicrobial strategies. Projects will be performed to determine the prevalence of foodborne pathogens (i.e., Escherichia coli O157:H7, Salmonella, and non-O157 STEC) and the level of aerobic bacteria on lamb carcasses processed in the United States. Understanding sources of carcass contamination will identify critical control points where antimicrobial intervention technologies need to be used to reduce or eliminate carcass contamination and to ensure wholesome meat. These results will be useful for the lamb industry and the USDA Food Safety and Inspection Service (FSIS).