Abstract
The genetic determinants of the O antigens of Sclmcnella were studied by using Hfr or F' crosses between strains of Salmonella groups B (S. ebony : O-1, 4, 5, 12; S. paratyphi B 8006 : O-4, 5, 12) and E4 (S. senftenberg : O-1, 3, 19). The main genetic determinants of the O antigens 4, 12 of group B and 3 of group E4 were considered to be alleles of one locus in so-called O, close to his locus. The genetic determinants of O antigens 1, 19 of group E4 was estimated to be linked to pro locus.
The O antigen of hybrids between S. senftenberg and S. paratyphi B 8006 which had received his and the genetic detetminant of 3 from S. senftenberg F' was converted from 3 to 3, 15 by infection of phage ε15. The strain thus lysogenized with ε15 became susceptible to phage ε34 and converted its O antigen 3, 15 to (3), (15), 34 by phage ε34. From the study using crosses between a strain of gronp B and the strains thus converted by ε15 and ε34, it was presumed that the prophage attachment site of ε34 (att ε34) is situated in the chromosomal leu-pro-nic region and that O antigens 3, 15 are necessary for the manifestation of the O antigen 34.
