Gram-negative rod shaped and very varied genus of bacteria found in animal and human intestines and in sewage. Unlike clostridium botulinum (whose spores produce the toxin), salmonella organisms themselves are toxic and (when ingested) cause different diseases and disorders according to their different strains: s. enteritidis causes food poisoning and gastroenteritis, s.paratyphi causes paratyphoid fever, and s.typhi causes the typhoid fever. Salmonella infections occur from consumption of contaminated food, specially eggs, fish, and poultry. Named after the US pathologist Daniel E. Salmon (1850-1914). See also salmonellosis.