Isolation and characterization of a new bacteriophage, KF1, immunologically cross-reactive with F-type pyocins

Pseudomonas aeruginosa strain NIH S produced a bacteriophage, KF1, immunologically cross-reactive with F-type pyocins. Phage KF1 was neutralized by both anti-pyocin F1 and anti-pyocin F3 sera, although the efficiency was very low. About eleven polypeptides were detected by SDS-polyacrylamide gel electrophoresis of the phage. Most of the subunit proteins were different from those of F-type pyocins, but the molecular weights of minor subunit proteins P3 and P6 seemed to be the same as those of band 1 and band 5 of F-type pyocins, respectively. The head of the phage appeared to have an icosahedral structure, approximately 63 nm in diameter, with a long (190 nm, 11 nm wide and about 45 striations) flexuous tail connected to a fiber structure (about 53 nm in length). The density in CsCl and the sedimentation coefficient of the phage were 1.54 g/ml and 392S, respectively. Some other biochemical properties were described. The nucleic acid of the phage was linear, double stranded DNA of molecular weight 4 x 10(7). The density of the DNA in CsCl was 1.719 g/ml, the melting temperature was 95.4 degrees C. The guanine plus cytosine content was calculated to be 60 to 64%.