1. Intestines: Salmonella primarily colonizes and reproduces within the gastrointestinal tract, specifically in the intestines. The bacteria can multiply rapidly in the small intestines, causing inflammation and associated symptoms such as diarrhea, abdominal pain, fever, and nausea.
2. Mesenteric Lymph Nodes: As part of the body's immune response, Salmonella can invade the mesenteric lymph nodes, which are located near the intestines. Within these lymph nodes, the bacteria can proliferate and cause inflammation.
3. Liver and Spleen: In severe cases, particularly with invasive non-typhoidal Salmonella (iNTS), the bacteria can spread through the bloodstream and reach the liver and spleen. Here, Salmonella can reproduce within the tissues and Kupffer cells of the liver and the macrophages of the spleen.
4. Gallbladder: In individuals with underlying conditions like gallstones or biliary abnormalities, Salmonella can colonize the gallbladder and multiply within the bile. This can lead to inflammation of the gallbladder (cholecystitis).
5. Other Sites: In rare instances, disseminated disease may occur, allowing Salmonella to spread to other organs and tissues beyond the gastrointestinal tract, such as the bloodstream (bacteremia), bones, joints, meninges, and heart valves. Reproduction can then occur within these infected sites.