Characterization of Salmonella isolates from beef cattle, broiler chickens and human sources on Prince Edward Island

Non typhoid Salmonella serovars remain a potential threat to human and animal health. Infection with Salmonella may not lead to fatal disease but rather it may remain localized in the gastro-intestinal tract resulting in gastroenteritis or may take a septicemic form that can affect several organ systems. Infected food animals that do not develop salmonellosis and those that recover from the disease may become carriers of Salmonella and serve as sources of infection to humans and animals. Apart from being a source of foodborne illness for humans, Salmonella-contaminated food animal carcasses are also of concern because they are a source of antibiotic-resistant Salmonella. This thesis describes studies on Salmonella carrier rate in the caeca of beef cattle and chickens from two meat processing plants on PEI, and comparative analysis of fasted and non-fasted cattle. In addition, drug resistance patterns and virulence characteristics of beef, chicken and human isolates during 1996-1997 were compared and the molecular aspects of virulence genes were investigated. All isolates were also examined by polymerase chain reaction (PCR) for the presence of virulence genes, invA and spvC sequence that enable salmonellae to grow and survive as an intracellular pathogen. (Abstract shortened by UMI.).