Date of Graduation

1-2015

Document Type

Thesis

Degree Name

Master of Science in Poultry Science (MS)

Degree Level

Graduate

Department

Poultry Science

Advisor

Dan J. Donoghue

Committee Member

Michael F. Slavik

Second Committee Member

Annie M. Donoghue

Keywords

Biological sciences; Campylobacter jejuni; Chicken; Post-harvest; Pre-harvest; Resorcylic acid

Abstract

Campylobacteriosis is one of the leading foodborne illnesses in United States, and is associated with the consumption of poultry and poultry products. Reducing Campylobacter in these species will reduce the burden of this disease. Unfortunately, most strategies employed to reduce Campylobacter in poultry have either not been successful or produced inconsistent results. One potential control strategy is the use of β-resorcylic acid (BR), a phytophenolic compound classified by the US FDA as "Everything Added to Food in the United States" (EAF 3045) and is therefore deemed safe for consumption. This compounds has antibacterial activity against Salmonella, however, its efficacy to control Campylobacter in poultry has not been evaluated. Preliminary studies in our laboratory demonstrated that BR kills Campylobacter jejuni, in vitro. Therefore, the objective of this study was to evaluate if BR would reduce Campylobacter in chickens. In pre-harvest studies, day of hatch chicks were fed one of five treatments (0, 0.25, 0.5, 1 or 2%BR) in the first trial, whereas a second trial was conducted including two additional doses of 0.75% & 1.5% BR (n=10 chicks/dose). Birds were challenged with mixture of four wild strains of C. jejuni (~ 106 CFU/mL) on day 7 and cecal samples were collected on day 14 and enumerated for Campylobacter. In post-harvest studies, four trials, two each on thigh skin and breast meat, were conducted. Chicken skin or meat samples (2±0.1g) were inoculated with 50µL of C. jejuni (~ 107 CFU/mL). Following 30 min of attachment, samples were dipped into their respective treatment solutions (0, 0.5, 1, 2% BR) for 30 s and suspended 2 min (n=10 samples/dose) and evaluated for reduction in Campylobacter counts. Campylobacter counts were reduced by 1.4 Log CFU/g for the 2% dose in the first pre-harvest trial and by 4.2 or 2.8 Log CFU/g for the 0.5 % & 1% BR doses in the second pre-harvest trial (P<0.05). In the post-harvest studies, all doses of BR significantly reduced Campylobacter counts in both meat and skin. Results of these experiments suggest post-harvest application of BR is the most effective treatment and may help reduce the incidence of human campylobacteriosis.

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