MOLECULAR-CLONING AND EXPRESSION OF SALMONELLA-TYPHI FLAGELLIN - CHARACTERIZATION OF 52 KDA SPECIFIC ANTIGEN OF SALMONELLA-TYPHI

We previously reported monoclonal antibodies (MAbs) specific to S. typ hi 52 kDa antigen which do not cross react with related protein antige ns from 11 bacteria causing enteric fever and enteric fever-like illne ss. Using the combination of these specific MAbs and recombinant DNA t echnology, expression plasmids containing the antigen gene producing s ubstantial amount of the S. typhi protein antigen have been establishe d. Plasmid pSKM-T7 containing the specific 52 kDa antigen gene was clo ned and the antigen expressed was detectable by immunoblotting using s pecific mAbs. The complete nucleotide sequence of this gene was compar ed with other bacterial sequences and found to be highly homologous wi th the flagellin gene H1-d of S. muenchen except in the hypervariable region in the central portion. The specific 52 kDa antigen of S. typhi detected by our MAbs is thus a flagellin.