s on shellfish stored at 10C to 13C and on ice in excess of 90 days (Salmonellae). It is inactivated in water within 1 day when exposed to 30% NaCl. Non-typhoid Salmonellae can survive for more than 10 weeks in butter at -23C and at 25C, and for 28 days on the surface of vegetables under refrigeration (Non-typhoid). They can survive in chocolate for months. They survives best in dry e3nvironments. Death occurs to most organisms during the freezing process, but those surviving remain viable during frozen storage, so freezing does not ensure the inactivation of Salmonellae in foods.
Salmonella cause a variety of clinical syndromes, including enteric fever, enterocolitis, bacteremia and severe local infections (Barrali; Giannella). Pathogenic Salmonellae ingested in food pass through the gastric acid barrier intact and invade the mucosa of the small and large intestines, where they produce toxins. To be fully pathogenic, Salmonellae must possess a number of attributes called virulence factors which include: 1) the ability to invade cells; 2) a complete polysaccharide coat; 3) the ability to replicate intracellularly; and 4) the ability to elaborate toxins. Once ingested, the organisms colonize the ileum and colon, invade the intestinal epithelium and proliferate within the epithelium and lymphoid follicles. The Salmonellae initially bind to specific receptors on the surface of the epithelial cells. The organisms then cause the epithelial cell membrane to endocytose the
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