|Genovese, Kenneth - Ken|
|Nisbet, David - Dave|
Submitted to: Food Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2008
Publication Date: 9/1/2008
Citation: Callaway, T.R., Edrington, T.S., Genovese, K.J., Anderson, R.C., Brabban, A., Kutter, E., Nisbet, D.J. 2008. Phage isolated from animal feces effectively reduce foodborne pathogens in the gut of cattle and swine [abstract]. Abstracts of the 21st International ICFMH Symposium, September 1-4, 2008, Aberdeen, Scotland. p. 109. Interpretive Summary:
Technical Abstract: Food animals can harbour foodborne pathogens (e.g., enterohemorrhagic E. coli and Salmonella spp.) in their gut that can be spread to humans via contaminated meat products or water and crops contaminated with pathogens by farm run-off. If the pathogen load can be reduced on the farm, then the effectiveness of in-plant intervention strategies can be enhanced, and pathogens entering the environment on-farm can be reduced as well. Bacteriophage are viruses that can kill bacteria and are commonly found in the gut of mammals and birds. Phages have been used to control pathogenic bacteria in many environments, including in human wounds. Recently, it was suggested that phage be used to control for use to control pathogens and must be selected for their activity against the specific pathogen(s) of interest and their ability to act within a specific environment. We have isolated phage from the intestinal tract of cattle, swine, and poultry with the goal of purifying them and utilizing them as a method to reduce E. coli O157:H7 from cattle and Salmonella enterica from cattle, swine, and poultry. We used bacteriophage that killed a generic E. coli strain used in our laboratory due to its sensitivity to phage as well as the pathogens E. coli O157:H7 and S. Typhimurium as targeted pathogens. In our field studies, we isolated phage that killed E. coli O157:H7 from 15% of all commercial cattle feces (n=560), and 55% of feedlot pens in two states. We isolated phage that killed the generic E. coli from 56% of individual swine fecal samples and phage against S. Typhimurium from 19% of fecal samples from 960 commercial pigs in four states. In poultry, however, we isolated phage against generic E. coli from 32% of the 240 fecal samples tested, but found only one phage active against S. Typhimurium. When phage were reintroduced into sheep (n=24; as a model of cattle) and swine (n=36) EC O157:H7, ST populations were reduced throughout the gut and were significantly lower (P less than 0.05) in the cecum of both species. However, when S. Typhimurium phage were added to broiler chicks (n=100), there was no impact on ST populations of the cecum. These results indicate that phage (predator) populations may vary along with food-borne pathogen (prey) populations, and that phage could potentially be used as a food safety pathogen reduction strategy, but that phage may have to be carefully selected for use in each food animal.