Kluyvera bacteriophage Kvp1: a new member of the Podoviridae family phylogenetically related to the coliphage T7

A DNA containing bacteriophage, Kvpl, was isolated from the water of a very polluted river, the Matanza river, near the central district of Buenos Aires City. This bacteriophage infects bacteria belonging to the Kluyvera cryocrescens species (strain 21g) isolated from the same river. Kvpl is a lytic bacteriophage and its propagation characteristics are: burst size 30, latent period 13 min and rise period 10 min. Morphologically, kvpl is a small icosahedral bacteriophage, 59.1 nm in diameter, which possesses a short wedge-shaped tail. Its buoyant density in ClCs is 1.517 g/cm3. Kvpl DNA is linear, double stranded and approximately 40 000 bp in size. The viral particle is composed of at least nine proteins. SDS-PAGE patterns of these proteins and of those produced during the host infection, in addition to its morphological and genomic characteristics, suggested that Kvpl is similar to the relationship to the coliphage. Taking this into account, the partial sequence of the phage RNA polymerase was used to construct phylogentic relationships between Kvpl and other related phages. To our knowledge, Kvpl is the first bacteriophage described which uses as host a member of the Kluyvera bacterial genus.