SF6032 - Antibiotic Replacement Therapy for Control of Food-Borne Pathogens in Poultry

Researcher:

Dr. Shayan Sharif, Dept. of Pathobiology, University of Guelph

Objectives:

1. To compare probiotics/prebiotics combinations for control of Salmonella burden in poultry.
   
2. To determine microbial changes in the gut microflora following probiotics/ prebiotics treatment.
   
3. To assess the effects of probiotic/prebiotic products on the immune system, systemically and at the gut level.
   
4. To recommend adoption of products to reduce Salmonella colonization.

Expected Benefits:

Findings of this study will facilitate the establishment and maintenance of a safe food chain by reducing food-borne pathogen burden and shedding in poultry. In addition, other benefits such as reduction in the use of antibiotics and its ensuing effects on emergence of antibiotic-resistant strains of bacteria and presence of antibiotic residues in human food, could be perceived.

Summary of Research Results:

The effects of two types of probiotics (two defined and two non-defined) in combination with a feed additive prebiotic, FOS, were studied on Salmonella reduction in caeca of commercial broiler chickens.  Both types of probiotics (defined and non-defined) reduced Salmonella typhimurium and S. heidelberg in the caeca of broilers at one and two weeks of age.  However, the non-defined probiotics had a more significant effect on reduction of Salmonella counts compared to defined probiotics.  Little benefit was observed among broilers treated with a feed additive prebiotic only or in combination with defined probiotics.  However, when the prebiotic additive was combined with non-defined probiotics, the combination was more effective than the probiotics alone in controlling Salmonella in the intestine.

Examination of the caecal contents of broilers revealed changes in the composition of the microflora associated with the defined probiotics mentioned above. The genera of the affected microbiota organisms could not be fully characterized.

The effects of one of the defined probiotics, containing Lacobacillus acidophilus, Bifidobacterium bifidum and Streptococcus faecalis on modulation of immune response was evaluated.  Our findings clearly demonstrated that when treated with this probiotic, immunized chickens mounted a significantly greater antibody response in their sera than the immunized birds that did not receive probiotics.  It remains to be determined whether probiotics can enhance immune responses in the gut.

In conclusion, our study demonstrates that defined and non-defined probiotics are capable of reducing Salmonella burden in broilers.  However, treatment of broilers with a combination of non-defined probiotics and prebiotics leads to more effective control of Salmonella.  In addition, early treatment with defined probiotics results in an enhancement of immune response.