Siphoviridae phage PH669 capable of lysing some strains of O3 and O4 serotypes in Vibrio parahaemolyticus

Abstract

Vibrio parahaemolyticus, especially serotypes O3 and O4, is a common foodbrone pathogen existing both in contaminate seafood and environment. The prevention and control of this pathogen are often limited to its geographic distribution and serotype diversity. Phage can be used as disinfectant and therapeutic agent from farm to fork. In this study, a phage named PH669 that can lyse V. parahaemolyticus was isolated from domestic sewage. The test of host range showed that PH669 has multiple serotypes lyse spectrum, including some O3 and O4 serotypes of V. parahaemolyticus strains as well as other serotypes. Biological characters revealed that PH669 has a wide range of temperature stability (from 4 °C to 50 °C) and pH stability (from 3 to 11), indicating it can be used in different environments. In addition, PH669 can effectively inhibit the growth of host bacteria starting from 30 min when the MOI (Optimal Multiplicity of Infection) is 1. PH669 is judged to belong to siphoviridae of bacteriophag based on its morphology. Genomic analysis showed that PH669 has a genome size of 58,644 bp, a G + C content of 46.3%, and 83 putative open reading frames (ORFs). Furthermore, no virulence or lysogen formation genes were predicted by the virulence factor database (VFDB) and Prophage Hunter in PH669 genome, respectively. The current results indicate that PH669 could be a potential agent both for phage therapy and disinfectant against pathogenic V. parahaemolyticus.