Author
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Stern, Norman |
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Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/14/2008 Publication Date: 11/16/2008 Citation: Stern, N.J. 2008. Salmonella species and Campylobacter jejuni Cecal Colonization Model in Broilers. Poultry Science. 87(11):2399-2403. Interpretive Summary: Campylobacter jejuni and Salmonella spp. remain significant bacterial pathogens of concern to the poultry industry because of associated transmission to the public through poultry products. To create effective interventions in live birds an appropriate and reproducible model for broiler intestinal colonization was needed. Such a colonization model already exists for Campylobacter. However, when 3 isolates of Salmonella were administered orally to young chicks, early colonization was lost by 4 weeks of age. Therefore, early Salmonella challenges could not be used to study colonization in mature (6 week old) animals. At 4 weeks of age, chickens were treated with vancomycin three hours before Salmonella challenge. This pre-treatment resulted in disruption of the gut microbial flora and substantial Salmonella colonization was observed in both 5 and 6 week old chicken groups. A reproducible colonization model has been created for subsequent intervention studies to control both Salmonella and Campylobacter in mature broiler chickens. Technical Abstract: Salmonella and Campylobacter are of concern to the poultry industry because of the continuing association of poultry-borne transmission of this disease to humans. Live, mature bird interventions can only be demonstrated by comparing colonization in non-treated groups of control birds to treated bird groups. This study attempted to create a reproducible broiler chicken colonization model. When 2-day post-hatch chicks were challenged with both Salmonella and Campylobacter, cecal colonization was achieved. By 4-weeks post-hatch, Salmonella counts g-1 cecal content diminished to very low or non-detectable 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 10-25 mg vancomycin was given to 4-week old broilers and 3 hours later a composite of 3 Salmonella isolates were gavaged into the chickens. Birds were sampled one and two weeks later. The data indicated that colonization was achieved at levels of 106-7 cfu gm-1 cecal materials (at week 5) and >102-4 cfu gm-1 cecal materials (at week 6). |
