ABSTRACT
Shigella sonnei KNIH104S, which was selected by Korean National Institute of Health, expresses form I-antigen as a somatic antigen. In this study, we cloned the genes responsible for form I-antigen synthesis from S. sonnei KNIH104S. A Sau3AI-generated cosmid library of S. sonnei KNIH104S plasmids were transfected into E. coli LE392 and transfectants were tested for agglutination with antiserum against S. sonnei form I-antigen. A clone, JH222, showing the strongest agglutination activity was chosen for further analysis. A recombinant cosmid, pJH222, was isolated from the strain JH222 and retransfected into E. coli LE392. All of the transfectants agglutinated with antiserum against form I-antigen, indicating that pJH222 carried the genes required for S. sonnei form I-antigen synthesis. Restriction analysis of pJH222 revealed a 38 kb insert, which was confirmed by Southern hybridization analysis to be present on a large plasmid of S. sonnei KNIH104S.