Production and epidemiological application of monoclonal antibody specific for Salmonella O5-antigen.

Salmonella typhimurium is an important causative agent of acute gastroenteritis (food poisoning), and the decision of the source of infection urgently requires epidemiological investigation. There are two types of S. typhimurium, O5-antigen-carrier type (O5(+)-antigen type) and noncarrier type (Copenhagen antigen type). On the assumption that serological differentiation of the types is effective for epidemiological exploration for the source of infection, we produced a monoclonal antibody, TMY1, specific for the O5-antigen. We classified S. typhimurium identified as the causative agent of mass outbreaks of acute Salmonella gastroenteritis according to the O5-antigen type, by using the TMY1. As a result, the bacterium in each outbreak was classified as the O5(+)-antigen type or the Copenhagen antigen type based on the difference in reactivity with TMY1. S. typhimurium isolated from calves in mass outbreaks of diarrhea and from animals with various diseases were also classified by TMY1 according to the O5-antigen type, and TMY1 was found to be as useful as in human cases. From this confirmation, TMY1 was demonstrated to be useful as a marker for epidemiological investigation of the source of infection by the O5-antigen type of S. typhimurium.