Definition of Salmonella genome

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Salmonella genome: The entire genetic complement (the DNA) of Salmonella bacteria.

The genomes of two strains of Salmonella bacteria have been sequenced. One strain is responsible for typhoid; the other causes food poisoning. The two strains of Salmonella are called Typhi and Typhimurium. Typhi, the typhoid agent, attacks the liver, spleen and bone marrow. Typhimurium lives in the gut and is a major cause of salmonella food poisoning.

The genome of Typhi contains more than 200 pseudogenes, once-functional stretches of DNA that have been inactivated by mutation. Working versions of these genes were discarded during evolution.

The genome of Typhimurium appears more flexible. It has only has around 40 pseudogenes so that its biological tool kit is bigger. Each strain of Salmonella has hundreds of genes that are not found in the other strain. There are over 2,000 strains of Salmonella. The genomes of several more strains are being sequenced.