<OL type="A"> <LI> Validate the antimicrobial efficacy of varying levels of peracetic acid in poultry chill water applications. <LI> Use bacteriophage and competitive exclusion as a pre-harvest antimicrobial intervention strategy. <LI> Relate meat quality to histochemical measures of myofiber diameter and collagen structure in rapid growing broiler lines.
NON-TECHNICAL SUMMARY: Poultry meat has been associated with food borne illness in humans and fast growing poultry exhibits meat quality defects. The purpose of this project is to identify factors that improve the safety and quality of poultry meat. <P>APPROACH: <BR>Objective A. Poultry chill water will be collected from a commercial poultry processing facility. Chlorine and organic load will be measured. Five treatments consisting of varying levels of peracetic acid and/or other antimicrobials will be prepared in chill water and placed in 5 gallon buckets. The water will be maintained at 4 C and chlorine levels will be tested to confirm they are at a minimal. For each treatment except for controls, 5, 5 gallon buckets will be used per replication. For each of 2 replications, processed broilers will be inoculated with Salmonella enterica Typhimurium (106) and Campylobacter jejuni (106) on the skin of the carcass. Inoculum procedures are described below: Once the inoculum has dried (10 minutes), the birds will be placed in the assigned treatment for 1 hour. Afterwards, the birds will be sampled by carcass rinse in buffered peptone water and Salmonella and Campylobacter will be enumerated to determine % reduction. <p>Objective B. Use of bacteriophage and competitive exclusion in vivo. Three day old chicks will be treated orally throughout a period of 3 days with a probiotic consisting of a pure culture of Bacillus subtilis and a cocktail of bacteriophages(5.4x106plaque forming units/0.5ml/bird) that have shown lytic activity against S. Typhimurium in vitro. Treated and control chickens will be challenged at day 7 of age with 0.5ml of a suspension of a spontaneous nalidixic acid resistant S. Typhimurium strain of chicken origin containing 2.4x105CFU/ml. Treatment with bacteriophages will be continued throughout days 8, 9, and 10 of age. Chickens will be euthanized and weighed at day 11 of age. Necropsy will performed and samples from ileal content and ileal wall, and ceca will be aseptically collected for quantitative bacteriology. A pool of spleen and liver will be obtained for qualitative bacteriology. Bacteriology will be conducted as described using appropriate media. Salmonella will be determined using xylose lysine tergitol 4 agar base (XLT4 agar) plates supplemented with nalidixic acid. Black colonies on the XLT4 plates will beconsidered Salmonella positive and will be confirmed with triple sugar-iron (TSI) agar slants. Samples that are considered positive on the TSI slants will be serologically confirmed with Salmonella O antiserum poly A-I and Vi test kit. Positive samples will be enumerated for Salmonella by the most probable number (MPN) procedure, whereas negative samples will be discarded. <p>Objective C. Birds from fast-growing commercial lines will be sampled for myofiver type and collagen determination. Myofiber type and collagen determination will be conducted using the following procedures using tissue samples that will be screen for muscle fiber type and stained for collagen determination.