Prevalence of Salmonella on Laying Hen Farms and Control of Colonization in Poultry through Egg Yolk Antibodies

Title of Document: PREVALENCE OF SALMONELLA ON LAYING HEN FARMS AND CONTROL OF COLONIZATION IN POULTRY THROUGH EGG YOLK ANTIBODIES. Jose Alejandro N. Almario, Master’s of Science, 2014 Directed By: Assistant Professor, Dr. Debabrata Biswas, Department of Animal and Avian Sciences In the United States, rates of foodborne illness caused by Salmonella have not changed significantly. One study in this thesis estimated Salmonella prevalence and antimicrobial resistance of various samples from conventional (n=181) and organic (n=252) farms. Rates of Salmonella contamination were significantly lower on conventional than organic farms. Antimicrobial resistance was significantly higher on isolates from conventional versus organic farms. These findings suggest that poultry production practices may have significant effects on prevalence and antibiotic resistance patterns of Salmonella. The other study assessed the efficacy of a Salmonella control strategy using antiSalmonella antibodies, two chicken cell lines, an HD-11 macrophage and a DF-1 fibroblast line, and Salmonella serovars Typhimurium and Enteritidis. In DF-1 cells, treatment showed decrease adherence of the pathogen. However, in HD-11 cells, treatment showed an increase in pathogen adherence, indicating a more detailed understanding of chicken response to treatment with the antibodies is needed before full-scale implementation.