mating experiments with a vi-antigen-expressing s. typhi hfr and an s. typhimurium hybrid recipient expressing the vi antigen of s. paratyphi c yielded no recombinants in which loss of vi antigen expression occurred , indicating that the chromosomal locus occupied by the genetic determinants of the s. paratyphi c vi antigen is the same one at which , in s. typhi , the viab genes reside .
C0008633
chromosomal
C1708726
locus