Complete genome sequence of a novel lytic phage infecting Aeromonas hydrophila, an infectious agent in striped catfish (Pangasianodon hypophthalmus)

Abstract

The bacteriophage vB_AhM_PVN02 (PVN02), infecting Aeromonas hydrophila, was isolated from a striped catfish pond water sample in Can Tho City, Vietnam. The phage had high lytic activity with a latent period and burst size of approximately 20 min and 105 plaque-forming units per cell, respectively. Observation of the phage by transmission electron microscopy indicated that PVN02 belongs to the family Myoviridae. The genome of PVN02 is a double-stranded linear DNA with a length in 51,668 bp and a content of 52% GC. Among the 64 genes, 16 were predicted to encode proteins with predicted functions. No virulence or antibiotic resistance genes were found in the genome, suggesting it would be a useful biocontrol agent. Classification of the phage based on sequence comparisons, phylogenetic analysis, and gene-sharing networks was carried out, and it was found to be the first representative of a new species within a previously undefined genus in the family Myoviridae. This study confirmed that PVN02 is a novel lytic phage that could potentially be used as an agent to control Aeromonas hydrophila in striped catfish in the Mekong Delta, Vietnam.