Life cycle details or ecological impact are well characterized only for a few ssDNA phages. The Finnlakeviridae family includes one species, Finnlakevirus FLiP . Here, using the same Flavobacterium host and sampling location, we isolated a new strain designated FLiP‐2, with 96.7% genetic identity to the original isolate FLiP. To understand the ecology of this Flavobacterium‐ infecting phage species, we explored the host intera...

A major bottleneck to the projected expansion of the aquaculture industry is disease outbreaks caused by bacterial pathogens. Fish diseases caused by Flavobacterium pathogens are persistent in salmonid aquaculture, and treatment is limited to antimicrobials, which contaminate the aquatic environment and promote antimicrobial resistance. Bacteriophages (phages) are viruses that naturally kill bacteria, and Flavobacterium ‐infec...

Yersinia enterocolitica causes yersiniosis, the third most common gastrointestinal infection in humans throughout Europe. The emergence of multidrug resistance and the lack of effective new antibiotics have drawn attention to phage therapy as a treatment option. Here, we report the complete genome sequence of phage fMtkYen3-01, which infects Y. enterocolitica serotype O:3 strains. This phage has a genome 40,415 bp in length wi...

The influence of environmental factors on the interactions between phages and bacteria, particularly single‐stranded DNA (ssDNA) phages, has been largely unexplored. In this study, we used Finnlakevirus FLiP, the first known ssDNA phage species with a lipid membrane, as our model phage. We examined the infectivity of FLiP with three Flavobacterium host strains, B330, B167 and B114. We discovered that FLiP infection is continge...

Increasing antimicrobial resistance (AMR) poses a challenge for treatment of bacterial diseases. In real life, bacterial infections are typically embedded within complex multispecies communities and influenced by the environment, which can shape costs and benefits of AMR. However, knowledge of such interactions and their implications for AMR in vivo is limited. To address this knowledge gap, we investigated fitness‐related tra...

Summary Intensive aquaculture conditions expose fish to bacterial infections, leading to significant financial losses, extensive antibiotic use and risk of antibiotic resistance in target bacteria. Flavobacterium columnare causes columnaris disease in aquaculture worldwide. To develop a bacteriophage‐based control of columnaris disease, we isolated and characterized 126 F . columnare strains and 63 phages against F . columnare...