1a. Objectives (from AD-416)
The objectives of this work include 1) Determine the efficacy of bacteriophage to prevent and treat colibacillosis (Escherichia coli); 2) Determine the efficacy of bacteriophage to prevent and treat turkey coryza (Bordetella avium);and 3) Determine the efficacy of bacteriophage to prevent and treat fowl cholera (Pasteurella multocida).
1b. Approach (from AD-416)
Bacteriophage will be isolated from environmental sources targeted for the bacteria E. coli, Bordetella avium, and Pasteurella multocide. Using our established colibacilosis model we will quantitatively determine the relationship between bacteriophage titers to therapeutic efficacy by treating colibacillosis with different bacteriophage titers, and will conduct in vitro studies to determine if there are any non-specific blood factors that inhibit bacteriophage activity. The efficacy of repeated treatment of bacteriophage will be conducted by administering bacteriophage prior to challenging the birds with the disease agent, and then treating them with an additional bacteriophage administration to determine if prior exposure to high titers of bacteriophage will limit the efficacy of bacteriophage to treat colibacillosis. Bacteriophage from environmental sources will be isolated with effectiveness against Bordetella avium and Pasteurella multocida. Studies will be conducted to determine the efficacy of aerosol administration of bacteriophage to prevent disease by administrating the bacteriophage prior to challenging the birds with Bordetella avium or Pasteurella multocida.
3. Progress Report
Bacteriophage Elicit an Immune Response in Poultry: One of the concerns with using bacteriophage to treat bacterial infections in animals and humans is that the animal could respond to the bacteriophage treatment producing antibodies to the bacteriophage, which would limit the efficacy of repeated treatment of chronic bacterial infections. Scientists in the Poultry Production and Product Safety Research Unit at Fayetteville, Arkansas have determined that indeed poultry mount an immunological response to bacteriophage which reduces bacteriophage efficacy to treat bacterial infections by approximately 50%. However, we have developed an in vitro assay that can be used to determine if bacteriophage differ antigenically, which would allow the pharmaceutical industry the basis to design bacteriophage products to prevent immune interference with bacteriophage efficacy. This assay could also be used in both animal and human clinical laboratories to customize bacteriophage treatment of bacterial infections. (NP103: Component 4, Poultry Respiratory Diseases)
5. Significant Activities that Support Special Target Populations
Huff, W.E., Huff, G.R., Rath, N.C., Donoghue, A.M. 2006. Evaluation of the influence of bacteriophage titer on the treatment of colibacillosis in broiler chickens. Poultry Science. 85:1373-1377.