Characterization and Properties of Phage B33, a Female-specific Phage of Pseudomonas aeruginosa

Abstract

SUMMARY The morphology and physico-chemical properties of a temperate phage, B33, ofPseudomonas aeruginosa have been determined. This phage is similar in size and structure to the previously described and serologically related phage B3 (Holloway, Egan & Monk, I96o), but differs from it in its plating properties on bacteria har- bouring R plasmids. The plasmid RPI-~ causes a reduction in e.o.p, of B33 of Io -6 , and the mechanism whereby this occurs has been studied. The interaction is a specific one since other plasmids either fail to affect plating or completely abolish it. The mechanism by which the latter occurs is different from that mediated by RPI-I, since mutants of B33 insensitive to RPI-1 nevertheless fail to plaque on these hosts.