Abstract: The biological properties of a lytic phage VpJYP2 that infects Vibrio parahaemolyticus were determined, and its bactericidal effect against V. parahaemolyticus in raw salmon fillets was analyzed as well. The results showed that the plaques of VpJYP2 were clear and about 1?2 mm in diameter with halos around them. VpJYP2 had an icosahedral head of about 64 nm in diameter and a tail of about 70 nm in length, with a tail sheath of 20 nm in width. VpJYP2 was identified to belong to the family Myoviridae. VpJYP2 had a genome of 25 363 bp containing 45 open reading frames (ORF), 13 of which were predicted to encode certain functional proteins. VpJYP2 was stable at 40?50 ℃ and under pH 4?11. Its optimal multiplicity of infection was 0.01. One-step growth experiments showed that its latent time and burst time were 5 and 55 min, respectively, and burst size was 45. VpJYP2 significantly reduced V. parahaemolyticus in raw salmon fillets. These results indicate that VpJYP2 can serve as a promising biocontrol agent against V. parahaemolyticus.

Key words: Vibrio parahaemolyticus; lytic phage; biological properties; bactericidal effect; raw salmon