Characterization of novel bacteriophage as a promising alternative for controlling Vibrio infections in shrimp

Vibrio parahaemolyticus is a significant pathogen affecting shrimp aquaculture, leading to substantial economic losses. This study aimed to isolate and characterize Vibrio phage with potential applications in controlling V. parahaemolyticus infections in shrimp. We isolated specific bacteriophages targeting V. parahaemolyticus from 61 shrimp samples collected from shrimp ponds. Among them, Vibrio phage P20211219001–1 was selected for characterization of its biological and morphological properties. The isolated Vibrio phage showed high host specificity, forming clear plaques on V. parahaemolyticus P20211219001–1, but no plaques on other tested Vibrio strains. The Vibrio phage P20211219001–1 exhibited an optimal multiplicity of infection (MOI) of 0.001, with a latent period of 20 min, a burst period of 30 min, and a burst size of 23 PFU/cell. Stability tests revealed that Vibrio phage P20211219001–1 remained stable at temperatures between 4 °C and 50 °C and across a broad pH range of 3 to 11. Morphologically, the phage featured a hexagonal head (83 nm) and a short tail (24 nm), belonging to the order Caudoviricetes. Genomic analysis of Vibrion phage revealed a 35,961 bp circular dsDNA genome with 41 predicted protein-coding sequences, including genes involved in phage structure, DNA replication, and host bacterial lysis. Lytic proteins identified include holins and N-acetylmuramoyl-L-alanine amidase. In application trials, Vibrio phage P20211219001–1 demonstrated significant protective effects against V. parahaemolyticus infection in Artemia salina and Litopenaeus vannamei, improving survival rates by 20–37 % compared to control. The results suggest that newly isolated Vibrio phage P20211219001–1 showed great potential for application in seafood safety, providing practical strategy for controlling V. parahaemolyticus infections.