A Google search of "Salmonella typhimurium antibody" shows that one commercially available antibody is, https://www.genwaybio.com/salmonella-typhimurium-61722, raised against the lipopolysaccharide, LPS antigen of S. Typhimurium, which is also commcercially available. There are many commcercially available sources of both anti- Salmonella typhimurium antibodies and the LPS antigen.