Isolation and Characterization of a Filamentous Phage, Vf33, Specific for Vibrio parahaemolyticus

Abstract

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.

A Filamentous Phage of Vibrio parahaemolyticus O3:K6 Isolated in Laos

“…The phage Ivpf5 was inactivated by heating at 80 C for 10 min or by treating with chloroform. These physicochemical properties of lvpf5 are similar to that of other filamentous phages reported (3,5,18).…”

“…Figure 6 shows the restriction map of lvpf5 constructed by Hind III, EcoR I, Kpn I and Pst I digestion fragments. The restriction patterns of lvpf5 phage were similar to those of vf33 phage (18). Recently, Chang et al reported the sequence of the vf33 gene (2).…”

“…The similarity of the N-terminal amino acid sequences between lvpf5 and vf33 that suggests that both phages have similar major coat proteins. Taniguchi et al reported the biological properties of vf33 in 1984 (18). At least two differences between lvpf5 and vf33 were presented: 1) lvpf5 did not make a single plaque even though 0.02% Tween 80 was contained on soft agar; and 2) organisms with various serotypes were sensitive to lvpf5 phage but only K38 to the vf33 phage.…”

Isolation and Genetic Characterization of a Novel Filamentous Bacteriophage, a Deleted Form of Phage f237, from a Pandemic Vibrio parahaemolyticus O4:K68 Strain

“…The culture supernatant of strain VpO4 was collected from an overnight L-broth culture and examined with an electron microscope as described by Taniguchi et al (13). It revealed the virion as a flexible filament, approximately 1,300 nm in length and 7 nm in width (data not shown).…”

“…At first, the nucleic acid of the VfO4K68 phage was purified from culture supernatant according to the standard protocol (13). The product obtained was electrophoresed on an LO3 agarose gel (TaKaRa Shuzo Co., Ltd., Kyoto, Japan), but no visible band was detected after ethidium bromide staining (data not shown).…”