Salmonella(salmonellafirst) is one of the most frequently isolated foodborne pathogens. It is a major worldwide public health concern, accounting for 93.8 million foodborne illnesses and 155,000 deaths per year. Salmonella was first discovered by Theobald Smith in 1855 , and isolated from the intestines of pigs infected with classical swine fever. The bacterial strain was named after Dr Daniel Elmer Salmon, an American pathologist who worked with Smith. The nomenclature of Salmonella is controversial and still evolving.