A1 Journal article (refereed)
Interactions between Rainbow Trout Eyed Eggs and Flavobacterium spp. Using a Bath Challenge Model : Preliminary Evaluation of Bacteriophages as Pathogen Control Agents (2021)

Donati, V. L., Dalsgaard, I., Runtuvuori-Salmela, A., Kunttu, H., Jørgensen, J., Castillo, D., Sundberg, L.-R., Middelboe, M., & Madsen, L. (2021). Interactions between Rainbow Trout Eyed Eggs and Flavobacterium spp. Using a Bath Challenge Model : Preliminary Evaluation of Bacteriophages as Pathogen Control Agents. Microorganisms, 9(5), Article 971. https://doi.org/10.3390/microorganisms9050971

JYU authors or editors

Publication details

All authors or editors: Donati, Valentina L.; Dalsgaard, Inger; Runtuvuori-Salmela, Anniina; Kunttu, Heidi; Jørgensen, Johanna; Castillo, Daniel; Sundberg, Lotta-Riina; Middelboe, Mathias; Madsen, Lone

Journal or series: Microorganisms

eISSN: 2076-2607

Publication year: 2021

Publication date: 30/04/2021

Volume: 9

Issue number: 5

Article number: 971

Publisher: MDPI AG

Publication country: Switzerland

Publication language: English

DOI: https://doi.org/10.3390/microorganisms9050971

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/75835


The microbial community surrounding fish eyed eggs can harbor pathogenic bacteria. In this study we focused on rainbow trout (Oncorhynchus mykiss) eyed eggs and the potential of bacteriophages against the pathogenic bacteria Flavobacterium psychrophilum and F. columnare. An infection bath method was first established, and the effects of singular phages on fish eggs was assessed (survival of eyed eggs, interaction of phages with eyed eggs). Subsequently, bacteria-challenged eyed eggs were exposed to phages to evaluate their effects in controlling the bacterial population. Culture-based methods were used to enumerate the number of bacteria and/or phages associated with eyed eggs and in the surrounding environment. The results of the study showed that, with our infection model, it was possible to re-isolate F. psychrophilum associated with eyed eggs after the infection procedure, without affecting the survival of the eggs in the short term. However, this was not possible for F. columnare, as this bacterium grows at higher temperatures than the ones recommended for incubation of rainbow trout eyed eggs. Bacteriophages do not appear to negatively affect the survival of rainbow trout eyed eggs and they do not seem to strongly adhere to the surface of eyed eggs either. Finally, the results demonstrated a strong potential for short term (24 h) phage control of F. psychrophilum. However, further studies are needed to explore if phage control can be maintained for a longer period and to further elucidate the mechanisms of interactions between Flavobacteria and their phages in association with fish eggs.

Keywords: bacteria; infections; fish diseases; bacteriophages; fish roe; rainbow trout

Free keywords: Flavobacterium psychrophilum; Flavobacterium columnare; rainbow trout; eyed eggs; phage-mediated control; bacteriophages

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Ministry reporting: Yes

Reporting Year: 2021

JUFO rating: 1

Last updated on 2022-20-09 at 15:41