GENETIC DETERMINATIONS OF THE O-ANTIGENS 3, 10 AND 15 IN SALMONELLA GROUP E

Abstract

1. The somatic antigens 3, 10 were transferred into a recipient of Salmonella paratyphi B 8006 (group B : 4, 5, 12) or S. paratyphi B uar. odense (group B : 1, 4, 12) by mating with a donor of (S-84) E1, an O-15 loss variant of S. newington C2 (group E1 3, 10) F'. The determinants of antigens 3, 10 were found to be closely linked to the his gene. Moreover, all of recombinants which received the determinants of antigens 3, 10 concurrently lost antigens 4, 12. On the other hand, the antigens 4, 12 were not transferred into a recipient of (S-84) E1 (group E1 : 3, 10) by mating with a donor of S. abony (group B : 1, 4, 5, 12) Hfr or S. paratyphi B 6617 (group B : 1, 4, 5, 12) F'. These results indicated that the genetic determinants of the somatic antigens 4, 12 and 3, 10 are probably allelic.2. Somatic antigens of S. paratyphi B 8006 or S. paratyphi B var. odense hybrid which had received his and determinants of antigens 3, 10 from (S-84) E1 F' strain were converted from 3, 10 to 3, 15 by phage e15. The phage-converted strain having antigens 3, 15 could not produce active phage e15, and furthermore it was difficult to find out antigenic reversions from 3, 15 to 3, 10 during the course of serial cultures of the strain in broth containing anti-15 monofactor serum. 3. The determinants of antigens 3, 15 were transferred into group B Salmonella or into the recombinants which received antigens 3, 10 from a cross between group E1 F' donor and group B recipient by mating with the donor of e15 phage-converted recombinant F' having 3, 15. It was found that the prophage attachment site of e15 at the host chromosome is close to met and O-5 (the locus for biosynthesis of somatic antigen 5) loci and not far away from his locus. 4. When prophage e15 had been integrated into a host bacterial chromosome of group B strains, the formation of somatic antigens 3, 15 could not be found in the absence of the antigen 3, 10. So, it was considered that the antigen 3, 10 is necessary not only for the acceptor to adsorb a phage e15, but also for the manifestation of the antigen 15.