Salmonella Species and Campylobacter jejuni Cecal Colonization Model in Broilers

Salmonella and Campylobacter are of concern to the poultry industry because of the continuing association of poultry-borne transmission of these diseases to humans. Live, mature bird interventions can be demonstrated only by comparing colonization in nontreated groups of control birds with treated bird groups. This study attempted to create a reproducible broiler chicken colonization model. When chicks were challenged 2 d posthatch with both Salmonella and Campylobacter, cecal colonization was achieved. By 4 wk posthatch, Salmonella counts per gram of cecal content diminished to very low or nondetectable levels. Campylobacter counts remained high throughout the test period. To achieve the goal of creating a mature bird Salmonella intestinal colonization model, oral treatment of 10 to 25 mg of vancomycin was given to 4-wk-old broilers, and 3 h later a composite of 3 Salmonella isolates were gavaged into the chickens. Birds were sampled 1 and 2 wk later. The data indicated that colonization was achieved at levels of 10(6-7) cfu g(-1) of cecal materials (at wk 5) and > 10(2) to 10(4) cfu g(-1) of cecal materials (at wk 6).