Isolation and characterization of Vibrio alginolyticus phage PV48 from Penaeus vannamei.

Vibrio alginolyticus is a zoonotic pathogenic bacterium that causes various diseases in marine animals, including Penaeus vannamei. Phage therapy, as a natural antibiotic, offers a novel approach to the prevention and control of vibriosis. In this study, we isolated, identified, and characterized a novel bacteriophage targeting V. alginolyticus, designated as PV48. PV48, a short-tailed bacteriophage isolated from the Ningbo aquaculture farm, possesses the ability to lyse V. alginolyticus strains that affect shrimp. It displays stability over a range of temperatures (30–50°C) and pH values (4–10). The latent period and burst size for phage PV48 were determined to be 20 minutes and 15.6 PFU/cell, respectively. Whole-genome sequencing revealed that PV48 has a dsDNA genome with a length of 43,398 bp and a G + C content of 49.54%. The phage genome contains 44 open reading frames (ORFs). Comparative genomic analysis suggested that PV48 might represent a new species within the genus Maculvirus. Phylogenetic analysis indicated a close evolutionary link between PV48 and other Vibrio-targeting phages, suggesting a shared viral lineage. This study lays the groundwork for the application of V. alginolyticus bacteriophage in aquaculture.