PUBLICATION

Zebrafish (Danio rerio) as an animal model for bath infection by Flavobacterium psychrophilum

Authors
Avendaño-Herrera, R., Benavides, I., Espina, J.A., Soto-Comte, D., Poblete-Morales, M., Valdés, J.A., Feijóo, C.G., Reyes, A.E.
ID
ZDB-PUB-200403-139
Date
2020
Source
Journal of fish diseases   43(5): 561-570 (Journal)
Registered Authors
Espina, Jaime, Feijoo, Carmen G.
Keywords
aquaculture, bacterial cold-water disease, immersion bath, rainbow trout fry syndrome
MeSH Terms
  • Animals
  • Disease Models, Animal*
  • Fish Diseases/microbiology*
  • Flavobacteriaceae Infections/microbiology
  • Flavobacteriaceae Infections/veterinary*
  • Flavobacterium/physiology*
  • Zebrafish*
PubMed
32196708 Full text @ J. Fish Dis.
Abstract
Flavobacterium psychrophilum is the causative agent of bacterial cold-water disease and rainbow trout syndrome in freshwater salmonid fish worldwide, generating injuries and high mortality rates. Despite several studies on this bacterium, the infection mechanism remains unknown due to limitations in the employed animal models. In this work, we propose using zebrafish (Danio rerio) as a model for studying bacterial pathogenicity. To substantiate this proposal, zebrafish infection by F. psychrophilum strain JIP 02/86 was characterized. Zebrafish larvae were infected using the bath method, and morphological changes and innate immune system activation were monitored using transgenic fish. Salmonid-like infection phenotypes were observed in 4.74% of treated larvae, as manifested by fin, muscle and caudal peduncle damage. Symptomatic and dead larvae accounted for 1.35% of all challenged larvae. Interestingly, infected larvae with no infection phenotypes showed stronger innate immune system activation than specimens with phenotypes. A failure of function assay for myeloid factor pu.1 resulted in more infected larvae (up to 43.5%), suggesting that low infection rates by F. psychrophilum would be due to the protective actions of the innate immune system against this bacterium in zebrafish larvae. Our results support the use of zebrafish as an infection model for studying F. psychrophilum. Furthermore, the percentage of infected fish can be modulated by disturbing, to varying extents, the differentiation of myeloid cells. Using this evidence as a starting point, different aspects of the infection mechanism of F. psychrophilum could be studied in vivo.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping