Isolation and characterization of a filamentous phage, Vf33, specific for Vibrio parahaemolyticus.

Phage Vf33, a filamentous phage about 1,400 nm long and 7 nm wide, specific for Vibrio parahaemolyticus, was isolated and characterized. The buoyant density of Vf33 in CsCl was 1.292 g/cm3. As with other filamentous phages, the lytic activity of Vf33 was resistant to heating below 80 C and to treatment with diethylether, acetone or methanol but sensitive to chloroform. The nucleic acid of this phage is single-stranded circular DNA 8.4 kb in size. The viral genome was converted to a double-stranded replicative form in the host-cell. Among the strains tested, only V. parahaemolyticus strains possessing K38 antigen was sensitive to the phage.