Lysogeny in Proteus rettgeri and the hostrange of P. rettgeri and P. hauseri bacteriophages.

Abstract

SUMMARY Twenty-two different phage-types of Proteus rettgeri were investigated for lysogeny by growing strains singly, in mixtures and by ultraviolet induction. Five of the strains were lysogenic for other members of the group. The phages differed from one another in host-ranges. Eighteen different lytic phages were isolated from sewage with action on one or more of the strains. The host-range of all 23 phages was tested against a number of P. hauseri, P. morganii, Providence and other intestinal organisms. Twelve of the phages had productive cycles of infection on 24 strains of P. hauseri; 21 of the phages attacked 19 Providence strains. Two of the phages lysed the same 2 out of 40 strains of Escherichia coli. The efficiencies of plating varied from 10-4 to unity. No action was demonstrated on any of the P. morganii or other strains tested. The host-range of 23 P. hauseri phages previously isolated from sewage and from lysogenic P. hauseri was tested against P. rettgeri, P. morganii and Providence strains. Three Providence and 2 P. morganii strains proved susceptible to productive infection by a number of the P. hauseri phages; 15 P. rettgeri strains were lysed by one or more of 18 P. hauseri phages. Some of the P. hauseri phages also caused abortive infection associated with cell death in some P. morganii and P. rettgeri organisms. The results indicate close ties between the P. hauseri and P. rettgeri groups, and between P. rettgeri and the Providence strains.