Completed Research

This research identified optimal methods to test for the presence of Salmonella spp. on the hides, carcasses and feces of cattle.

This research evaluated a specific bacteriophage treatment intended to reduce the probability of infection with E. coli and/or the amount shed if an infection was present. The bacteriophage treatment was not effective in reducing shedding of E. coli O157:H7 in calves. A “Trojan calf” model was developed which showed that all animals that come in contact with an animal shedding E. coli in a confined space will test positive.  

Probiotic bacterium (Lactobacillus acidophilus; NPC 747 and NPC 750) was added to cattle feed to determine its effect on the elimination or reduction of E. coli O157:H7 in cattle. The probiotic bacterium significantly decreased the number of cattle shedding E. coli O157:H7, and had either no effect or slightly improved the feedlot performance of finishing beef steers.

This project determined the antimicrobial activity of different levels of protamine, a natural antimicrobial, on Salmonella, E. coli and Listeria monocytogenes on meat and poultry before and after cooking.

The ability to distinguish between virulent and avirulent sublcones of E. coli O157:H7 was determined by genetic fingerprinting. Methods were developed and refined to improve the analysis of data in this field.

Cetyl pyridinium chloride (CPC) was evaluated through various application parameters for its antimicrobial effects on ready-to-eat meat and poultry products in an effort to retard growth of and/or eliminate Listeria monocytogenes.

This study focused on the development of a vaccine that would be delivered orally through corn using intiminO157 to prevent cattle from becoming infected with E. coli O157:H7. Further studies are being conducted on intimin.

This research evaluated the ability of various non-pathogenic colicin producing strains of E. coli to inhibit the growth of E. coli O157 and Shiga-toxin producing strains. Selected strains were able to inhibit the growth of O157:H7 in a laboratory environment.

This research evaluated three different doses of Lactobacillus acidophilus strain NP 51 and a combination treatment of NP51 and NP45 on the prevalence of Escherichia coli O157 in finishing beef cattle. The highest concentration of NP51 was the most effective in reducing fecal shedding. There were no detrimental effects of the treatments used in these studies on animal performance.

This series of studies demonstrated that surface electron-beam irradiation on beef dramatically reduced levels of E. coli O157:H7 while have no measurable impact on organoleptic, shelf life or nutritional status or resulting beef products.