Basic characterization of a Pseudomonas aeruginosa pilus-dependent bacteriophage with a long noncontractile tail

Bacteriophage PO4 has been found to depend on the presence of pili for the infection of its host organism, Pseudomonas aeruginosa. Unlike other pilus phages, which either contain RNA and are "spherical" or contain single-stranded DNA and are filamentous, PO4 has a head and a long noncontractile tail. This paper describes its basic characters, and a quantitative study is made of its adsorption to exponential-phase cells of piliated and nonpiliated strains of P. aeruginosa. PO4 is found to contain double-stranded DNA and appears to be virulent towards its two host strains.