Quantitative immunoelectrophoretic analysis of Salmonella typhi antigens and of corresponding antibodies in human sera.

By quantitative immunoelectrophoretic methods, 86 different antigens were found in sonicated preparations of a Salmonella typhi, using corresponding rabbit antiserum. Lipopolysaccharide was identified, and 5 other antigens characterized. Antibodies against a total of 19 S. typhi antigens were found in human sera. The antibody response in patients with typhoid fever was significantly more pronounced compared to that in normal persons. When the antibody response was expressed as a precipitin score, the predictive value of both a positive (precipitin score greater than or equal to 8) test and a negative test was 100%, when sera from patients suffering from typhoid fever were compared with sera from normal persons.