Article
Biology
Moonika H. Marana, Inger Dalsgaard, Per Walter Kania, Abdu Mohamed, Jens Hannibal, Kurt Buchmann
Summary: The study showed that an injection vaccine can reduce the shedding of Flavobacterium psychrophilum from older rainbow trout, increase antibody titers against multiple serotypes, and decrease infection risk at farm level.
Article
Microbiology
Valentina L. Donati, Inger Dalsgaard, Anniina Runtuvuori-Salmela, Heidi Kunttu, Johanna Jorgensen, Daniel Castillo, Lotta-Riina Sundberg, Mathias Middelboe, Lone Madsen
Summary: The study focused on potential bacteriophages against pathogenic bacteria associated with rainbow trout eyed eggs. Results showed strong potential for short term (24 h) phage control of Flavobacterium psychrophilum, but limitations in affecting F. columnare. Further studies are needed to explore long-term phage control and interaction mechanisms with fish eggs.
Article
Multidisciplinary Sciences
Mio Takeuchi, Erina Fujiwara-Nagata, Taiki Katayama, Hiroaki Suetake
Summary: Research on manipulating the skin microbiome is important for combating rainbow trout diseases, and using cultivation combined with sequencing helps to identify skin bacteria that can antagonize Flavobacterium psychrophilum.
SCIENTIFIC REPORTS
(2021)
Article
Biotechnology & Applied Microbiology
Segolene Calvez, Nora Navarro-Gonzalez, Charlene Siekoula-Nguedia, Catherine Fournel, Eric Duchaud
Summary: This study assessed the genetic diversity of Flavobacterium psychrophilum isolates from apparently healthy rainbow trout from several fish farms in the same watershed in France. High diversity was revealed by two different genotyping methods, with the majority of isolates being unrelated to the predominant clonal complex worldwide. Thirteen novel sequence types were discovered, suggesting a diverse subpopulation of F. psychrophilum in rainbow trout.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Immunology
Furong Deng, Di Wang, Thomas P. Loch, Fuguang Chen, Tongyan Lu, Yongsheng Cao, Dan Fan, Shaowu Li
Summary: This study utilized RNA-seq analysis to investigate the molecular mechanism of immune response in rainbow trout spleen during Flavobacterium psychrophilum infection. The results revealed key signaling pathways and provided valuable insights for future research on prevention and control of bacterial coldwater disease in salmon culture.
FRONTIERS IN IMMUNOLOGY
(2022)
Article
Microbiology
Jiyeon Park, Hyeongjin Roh, Yoonhang Lee, Ju-Yeop Lee, Hyo-Young Kang, Min Ji Seong, Yura Kang, Young Ung Heo, Bo Seong Kim, Chan-Il Park, Do-Hyung Kim
Summary: This study reports the first detection of Flavobacterium psychrophilum in Korea and describes its genotypic and phenotypic characteristics. The study also reveals the pathogenicity and antibiotic resistance of the pathogen and proposes control measures. This is important for understanding the impact of this pathogen on Korean rainbow trout populations and establishing surveillance and control measures to prevent further transmission and outbreaks.
Article
Fisheries
Jie Ma, Jesse T. Trushenski, Evan M. Jones, Timothy J. Bruce, Doug G. McKenney, Gael Kurath, Kenneth D. Cain
Summary: This study explores the maternal immunity in rainbow trout aquaculture, showing that vaccination of broodstock can reduce mortality in offspring from viral and bacterial diseases.
FISH & SHELLFISH IMMUNOLOGY
(2023)
Article
Fisheries
Izzet Burcin Saticioglu, Hilal Ay, Soner Altun, Nevzat Sahin, Muhammed Duman
Summary: In the study of farmed rainbow trout samples in Rize, Turkey, two novel Flavobacterium species were discovered, and their taxonomic positions were confirmed through 16S rRNA gene sequence analysis. A polyphasic taxonomy approach was employed to establish the novelty of these strains, leading to the proposal of Flavobacterium bernardetii sp. nov. The isolates were found to have unique genomic and phenotypic characteristics, indicating a possible correlation with mortality in rainbow trout.
Article
Microbiology
Maialen Aldabaldetrecu, Mick Parra, Sarita Soto-Aguilera, Pablo Arce, Amaya Paz de la Vega Quiroz, Rodrigo Segura, Mario Tello, Juan Guerrero, Brenda Modak
Summary: The study showed that adding [Cu(NN1)(2)](ClO4) as a dietary supplement to rainbow trout for 15 days at doses of 29 and 58 μg/g fish did not affect growth, but resulted in changes in copper concentration in the intestine and muscle. High copper levels were detected in pond water after feeding with the complex. The administration of [Cu(NN1)(2)](ClO4) at 58 μg/g of fish for 15 days showed a 75% survival rate against F. psychrophilum.
Article
Immunology
Ali Ali, Mohamed Salem
Summary: This study identified 13,503 long noncoding natural antisense transcripts (lncNATs) in rainbow trout using 134 RNA-Seq datasets. Most of the lncNATs showed strong positive correlation with their corresponding sense transcripts. Differential expression analysis revealed that lncNATs complementary to genes related to immunity, muscle contraction, proteolysis, and iron/heme metabolism were differentially expressed following infection. lncNATs complementary to hepcidin, a master negative regulator of plasma iron concentration, were downregulated in resistant fish on day 5 of bacterial infection.
FRONTIERS IN IMMUNOLOGY
(2022)
Article
Fisheries
Furong Deng, Di Wang, Fuguang Chen, Tongyan Lu, Shaowu Li
Summary: This study identified and functionally characterized OmCLDN4L protein in rainbow trout. OmCLDN4L plays a crucial role in the rainbow trout's immune response to bacterial infection and provides new insights into the molecular mechanism of intestinal barrier in rainbow trout against F. psychrophilum infection.
FISH & SHELLFISH IMMUNOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Izzet Burcin Saticioglu, Hilal Ay, Soner Altun, Muhammed Duman, Nevzat Sahin
Summary: During a study on culturable microorganisms from fish farms, two novel species within the genus Flavobacterium were identified, named Flavobacterium kayseriense and Flavobacterium turcicum, based on 16S rRNA gene sequence analysis and polyphasic taxonomic approaches. The strains F-47(T) and F-339(T) represent these novel species with unique genomic characteristics and taxonomic positions.
SYSTEMATIC AND APPLIED MICROBIOLOGY
(2021)
Article
Fisheries
Juan-Ting Liu, Phuc H. Pham, John S. Lumsden
Summary: Feeding rainbow trout with deoxynivalenol (DON) or partially feeding (pair-fed) can significantly reduce mortality rates when infected with Flavobacterium psychrophilum. Fasted or DON-fed fish showed increased autophagy in the liver, while fasted fish showed decreased autophagy in muscle. Treatment with chloroquine (CQ) increased Atg gene expression in the liver. The mechanisms behind the resistance of rainbow trout fed DON, CQ, or pair-fed to F. psychrophilum infection are still unclear.
JOURNAL OF FISH DISEASES
(2022)
Article
Microbiology
David Huyben, Maureen Jarau, Janet MacInnes, Roselynn Stevenson, John Lumsden
Summary: The diversity and composition of intestinal microbiota in rainbow trout were analyzed using next-generation sequencing (NGS). The study found that prophylactic oral treatment with antibiotics and infection with Flavobacterium psychrophilum altered the composition of intestinal microbiota in rainbow trout, and this alteration persisted for at least 24 days after infection.
Article
Fisheries
Brian W. Avila, Dana L. Winkelman, Eric R. Fetherman
Summary: Research has shown that rainbow trout crosses created by mating resistant strains can exhibit some level of pathogen resistance, but not all crosses show resistance, and only a few multigenerational strains are suitable for further evaluation.
JOURNAL OF FISH DISEASES
(2022)
Article
Limnology
Clemens Schauberger, Mathias Middelboe, Morten Larsen, Logan M. Peoples, Douglas H. Bartlett, Finn Kirpekar, Ashley A. Rowden, Frank Wenzhoefer, Bo Thamdrup, Ronnie N. Glud
Summary: Research on prokaryotic and viral abundance in hadal trenches and abyssal regions revealed a high spatial heterogeneity in hadal sediments, indicating a higher relative importance of viruses in hadal settings compared to abyssal environments.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Microbiology
Anniina Runtuvuori-Salmela, Heidi M. T. Kunttu, Elina Laanto, Gabriel M. F. Almeida, Kati Makela, Mathias Middelboe, Lotta-Riina Sundberg
Summary: Intensive aquaculture conditions expose fish to bacterial infections, leading to financial losses, antibiotic overuse, and the risk of antibiotic resistance. This study isolated and characterized F. columnare strains and phages against F. columnare from Finland and Sweden. The results showed that phages had modular infection patterns based on host genetic group. Despite differences, whole-genome sequencing of phages showed high genetic similarity to previously isolated F. columnare phages. These findings suggest the potential of phage therapy for controlling columnaris disease in aquaculture.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Microbiology
Valentina Laura Donati, Lone Madsen, Mathias Middelboe, Mikael Lenz Strube, Inger Dalsgaard
Summary: This study investigated the effects of antibiotics and phage therapies on the gut microbiota of rainbow trout fry, with a focus on the pathogen Flavobacterium psychrophilum. The results showed that both the infection and the administration of antibiotics caused dysbiosis in the fish gut. Additionally, the addition of phages altered the fish microbiota regardless of the presence of the target bacterium. However, there were no observed negative effects on fish health or growth. Further studies should focus on determining the benefits or disadvantages of these changes for fish health and the host immune response.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Environmental Sciences
Sachia J. Traving, John Paul Balmonte, Dan Seale, Carol Arnosti, Ronnie N. Glud, Steven J. Hallam, Mathias Middelboe
Summary: Extracellular enzyme activity is an important factor in evaluating microbial biogeochemical roles in marine ecosystems. However, understanding the enzyme activities at the single-cell level in natural communities is challenging. By studying enzyme activities at the single-cell level, we can gain insights into phenotypic heterogeneity, enzyme kinetics, and spatial-temporal distribution of enzyme producers in marine communities.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Microbiology
Johanna Jorgensen, Krister Sundell, Daniel Castillo, Liv S. Dramshoj, Natasja B. Jorgensen, Susie B. Madsen, Lotta Landor, Tom Wiklund, Valentina L. Donati, Lone Madsen, Inger Dalsgaard, Mathias Middelboe
Summary: This study genome sequenced and characterized 27 phage-resistant isolates of F. psychrophilum to identify genetic modifications and evaluate changes in phenotypic traits. The phage-resistant isolates showed reduction or loss of gliding motility, proteolytic activity, and adhesion to surfaces, and most of them were non-virulent against rainbow trout. Genomic analysis revealed that most phage-resistant isolates had mutations in genes associated with gliding motility and virulence. Reversal of these mutations led to regained motility, proteolytic activity, virulence, and phage susceptibility in a subset of isolates. The study suggests that phage administration in aquaculture systems selects for non-virulent phage-resistant phenotypes in F. psychrophilum.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Fisheries
Mirjam Boonstra, Belen Fouz, Betty van Gelderen, Inger Dalsgaard, Lone Madsen, Eva Jansson, Carmen Amaro, Olga Haenen
Summary: The study aimed to evaluate the accuracy of MALDI-TOF mass spectrometry in the identification of SerE from V. vulnificus. Serovar-specific peaks were found for SerE at approximately 3098 Da and 4045 Da, for SerA at approximately 3085 Da and 4037 Da, and for SerI at approximately 3085 Da and 4044 Da. Therefore, MALDI-TOF can be used to identify SerE and aid in the identification of other serovars, potentially preventing zoonotic transmission.
JOURNAL OF FISH DISEASES
(2023)
Article
Agriculture, Dairy & Animal Science
Julia Eidsmo, Lone Madsen, Lars-Flemming Pedersen, Alfred Jokumsen, Manuel Gesto
Summary: Enriching the living environment of captive fish can improve their welfare, but studies on the feasibility of implementation in real farming scenarios are limited. This study tested the feasibility of using plastic shelters to improve rainbow trout welfare in an organic fish farm. The shelters had no negative effects on fish performance, health, or mortality, but there were no clear shelter-seeking behavioral responses from the fish when disturbed. It is recommended to test enrichment strategies in real scenarios for a relevant part of the fish's life cycle to fully understand their potential for improving welfare in aquaculture.
Article
Microbiology
Jesper Juel Mauritzen, Emilie Sondberg, Panos G. G. Kalatzis, Line Roager, Lone Gram, Sine Lo Svenningsen, Mathias Middelboe
Summary: Bacterial populations communicate and coordinate behavior using quorum-sensing molecules. Vibrio anguillarum, a marine fish pathogen, has multiple quorum-sensing systems, but our understanding of its regulation is limited. This study identified the VanT-QS regulon and explored the diversity and trajectory of traits regulated by quorum sensing in V. anguillarum. Furthermore, it was found that quorum sensing controls various genes involved in essential processes and virulence properties, with significant strain-specific differences.
ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Panos G. Kalatzis, Jesper Juel Mauritzen, Caroline Sophie Winther-Have, Slawomir Michniewski, Andrew Millard, Maria Ioanna Tsertou, Pantelis Katharios, Mathias Middelboe
Summary: Bacteriophages are abundant in the oceans and play important roles in bacterial activity, diversity, and evolution. The non-tailed viruses (Class: Tectiliviricetes) are less studied compared to tailed viruses (Class: Caudoviricetes). This study reports the discovery of a new family of temperate phages, Asemoviridae, widely distributed in marine environments and found in Vibrio species. These phages interact with the host bacteria, potentially contributing to their global distribution through increased virulence and biofilm formation.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Fisheries
Heidi Mathiessen, Yajiao Duan, Moonika H. Marana, Shaozhi Zuo, Asma M. Karami, Rzgar Jafaar, Louise von Gersdorff Jorgensen, Per W. Kania, Inger Dalsgaard, Lone Madsen, Torben Nielsen, Fabian Grammes, Jorgen odegard, Valeria Macchia, Kurt Buchmann
Summary: Flavobacterium psychrophilum is the causative agent of Bacterial Cold Water Disease (BCWD)/ Rainbow Trout Fry Syndrome (RTFS) in rainbow trout. The disease causes significant mortality in trout farms and leads to economic losses in the aquaculture industry. The immature development of adaptive immunity in young life cycle stages hinders successful vaccination, resulting in the widespread use of antibiotics. Selective breeding and identification of markers associated with disease resistance may improve breeding efforts for more resilient strains.
AQUACULTURE REPORTS
(2023)
Article
Fisheries
Peter Smith, Laetitia Le Devendec, Eric Jouy, Emeline Larvor, Alain Le Breton, Sara Picon-Camacho, Snjezana Zrncic, Ivana Giovanna Zupicic, Drazen Oraic, Suheyla Karatas, David Verner-Jeffreys, Andrew Wokorac Joseph, Edel Light, Alieda van Essen-Zandbergen, Betty van Gelderen, Michal Voorbergen-Laarman, Olga L. M. Haenen, Kees T. Veldman, Lone Madsen, Kari K. Mouritsen, Cecilie Smith Svanevik, Fredrik Hakonsholm, Ana Isabel Vela, Maria Garcia, Daniela Florio, Marialetizia Fioravanti, Luana Cortinovis, Tobia Pretto, Amedeo Manfrin, Sandrine Baron
Summary: This study aimed to generate data for setting epidemiological cut-off values for MIC and disc-diffusion zone measurements of Vibrio anguillarum. Standard methods were applied to test 261 unique isolates in 9 laboratories. Statistical methods were used to calculate cut-off values, but some data did not meet the statistical requirements.
DISEASES OF AQUATIC ORGANISMS
(2023)
Article
Fisheries
Sanni L. Aalto, Lone Madsen, Lars-Flemming Pedersen
Summary: Dual-staining flow cytometry allows accurate quantification of live and dead cells, making it a potential tool for studying the mode-of-action of disinfection chemicals and supporting microbial control in aquaculture systems.
Article
Microbiology
Daniel Castillo, Alexander Ravndal Hojsting, Andrea Roosvall, Giorgos Smyrlis, Johanna Jorgensen, Mathias Middelboe
Summary: This study successfully isolated and evolved F. psychrophilum phages using two simple and fast strategies. The evolved phages exhibited improved host range and infection efficiency, which could be used to expand the targeting range of phages and treat Flavobacterium infections.
PHAGE-THERAPY APPLICATIONS AND RESEARCH
(2022)