Salmonella enterica (formerly Salmonella choleraesuis) is a Gram-negative bacterium. A number of its serovars are serious human pathogens.
Most cases of salmonellosis are caused by food infected with S. enterica, which often infects cattle and poultry, though other animals such as domestic cats and hamsters have also been shown to be sources of infection in humans. Raw chicken eggs and goose eggs can harbor S. enterica, initially in the egg whites.
Salmonella can invade different cell types, including epithelial cells, M cells, macrophages, and dendritic cells.