AN IMMUNOBLOTTING PROCEDURE COMPRISING O=9,12 AND H=D ANTIGENS AS AN ALTERNATIVE TO THE WIDAL AGGLUTINATION ASSAY

Aims-To compare the established Widal agglutination assay with an immu noblotting procedure. Methods-110 sera were used to compare the establ ished Widal agglutination assay with an immunoblotting procedure incor porating lipopolysaccharide (LPS) (O = 9, 12) and flagellar (H = d) an tigens. Results-Antibodies to the LPS antigens were detected in 18 ser a by the Widal assay and in 37 by immunoblotting. Antibodies to the fl agellar antigens were detected in 27 sera by Widal assay and in 25 by immunoblotting. Conclusions-An immunoblotting procedure incorporating O = 9, 12 LPS and H = d flagellar antigens was rapid and more sensitiv e than the established Widal agglutination assay for providing evidenc e of infection with S typhi.