Microbial food borne pathogens. Salmonella

All food animals are susceptible to infection with Salmonella, a genus of gram negative, nonspore-forming, usually motile, facultative anaerobic bacilli belonging to the family Enterobacteriaceae. Salmonella are differentiated into over 2200 serologically distinct types (serotypes) based on differences in somatic, flagellar, and capsular antigens. Infection with Salmonella may or may not lead to a sometimes fatal salmonellosis, a disease that can remain localized in the gastrointestinal tract as gastro-enteritis, or become generalized as a septicemia and affect several organ systems. Infected food animals that do not develop salmonellosis, and those that recover from the disease, become carriers of Salmonella and serve as sources of infection to humans and other animals. Apart from being a source of Salmonella food poisoning for humans, Salmonella-contaminated food animal carcasses are also a concern because they are a source of antibiotic-resistant Salmonella.