How do salmonella species cause disease (s)?

Ingested . Salmonella spp. Are contracted through food, water, and contaminated hands. Once in the intestine they can cause diarrhea or spread to the blood and possibly other organs.
Intestine. The salmonella bacteria enter the body through the GI tract and then gain access to the bloodstream by going through the lymphatic channels on the intestinal tract. The bacteria then travel around the circulation and infect various organs causing disease.