The SPI-19 encoded type-six secretion-systems (T6SS) of Salmonella enterica serovars Gallinarum and Dublin play different roles during infection.

•Salmonella Dublin and S. Gallinarum express type six secretion systems (T6SS) from SPI19.•In S. Dublin, the system was found to be important for virulence after oral challenge.•In S. Dublin, it influenced the competitive growth with strains of E. coli.•In S. Gallinarum, no significant influence on oral or intra peritoneal virulence could be found.•However, in S. Gallinarum, the system influenced cytotoxicity towards primary macrophages.