Related Experiment Video
Updated: May 5, 2026

Author Spotlight: Efficiently Eliminating Bacteriophages from Infected Salmonella Cultures Using Lipopolysaccharides
Published on: June 28, 2024
Genomic structure of bacteriophage 6H and its distribution as prophage in Flavobacterium psychrophilum strains
Daniel Castillo1, Romilio Espejo, Mathias Middelboe
1Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark; Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Macul, Santiago, Chile.
Abstract:
Flavobacterium psychrophilum is currently one of the most devastating fish pathogens worldwide causing considerable economic losses in salmonid aquaculture. Recently, attention has been drawn to the use of phages for controlling F. psychrophilum, and phages infecting the pathogen have been isolated. Here, we present the genome sequence of F. psychrophilum bacteriophage 6H and its distribution as prophage in F. psychrophilum isolates. The DNA sequence revealed a genome of 46 978 bp containing 63 predicted ORFs, of which 13% was assigned a putative function, including an integrase. Sequence analysis showed > 80% amino acid similarity to a specific region found in the virulent F. psychrophilum strain JIP02/86 (ATCC 49511), suggesting that a prophage similar to phage 6H was present in this strain. Screening for a collection of 49 F. psychrophilum strains isolated in Chile, Denmark, and USA for the presence of four phage 6H genes (integrase, tail tape protein and two hypothetical proteins) by PCR showed the presence of these prophage genes in 80% of the isolates. In conclusion, we hypothesize that bacteriophage 6H belongs to an abundant group of temperate phages which has lysogenized a large fraction of the global F. psychrophilum community.
Related Concept Videos
DNA Bacteriophages
Lytic Cycle of Bacteriophages
Lysogenic Cycle of Bacteriophages
Viral Replication: Lysogenic Cycle
Viral Replication: Lytic Cycle
Bacterial Phylum Bacteroidota

