Proteins located within SPI-1, -2, -4, and -5 showed the greatest diversity and these in particular included proteins critical in infection and persistence such as SiiEFG that functions in bacterial adhesion and invasion, SseFG, SopB, which are essential in Salmonella containing vacuole stabilization and replication and PipABC which are involved in entropathogenicity (Wood et al., 1998; Morgan et al., 2007; Ibarra and Steele-Mortimer, 2009). This evidence concerns the gene SPI1 and infection.