Salmonella 3. Attaches to intestinal and colonic cells, and injects proteins that stimulate internalization 4. Spreads to mesenteric nodes Salmonella choleraesuis and S typhi often enter the bloodstream and cause bacteremiaSalmonella 3. Attaches to intestinal and colonic cells, and injects proteins that stimulate internalization. 4. Spreads to mesenteric nodes; Salmonella choleraesuis and S. typhi often enter the bloodstream, and cause bacteremia. 12