Identification and characterization of the novel bacteriophage BPVP-3325 for the biocontrol of Vibrio parahaemolyticus infection in seafood

A total of 19 bacteriophages were isolated from seawater, wet sand, sea rocks, and suspended solids collected from 10 different sites in Busan, Republic of Korea. Among them, the best-performed novel phage was designated as BPVP-3325 that demonstrated the highest lytic activity in 76% of the total studied strains of Vibrio parahaemolyticus. The complete genome of the novel phage was 222,634 bp with 42% G + C content; electron microscopy showed that the total length and head length were 411.66 +/- 6.69 and 129.87 +/- 5.10 nm, respectively. In vitro characterization, V. parahaemolyticus ATCC 17802 was used as a standard pathogenic strain of BPVP-3325 host. The latent period was approximately 40 min, and the burst size was 6.76 PFU/infected cell. BPVP-3325 demonstrated excellent efficacy in a relatively wide pH range of up to 5-10 and temperature of <50 degrees C. When ATCC 17802 was treated with BPVP-3325 in a liquid medium for 6 h, OD600 in the phage-treated group was significantly lower (similar to 50%) than that in the host. The application of BPVP-3325 to oyster meat effectively inhibited the growth and activity of the standard strain (P < 0.05). Therefore, this study described the potential of novel BPVP-3325 therapy for natural oyster culture and food industry for the biocontrol of V. parahaemolyticus disease in aquaculture and human food.