Saprolegnia parasitica Isolated from Rainbow Trout in Korea: Characterization, Anti- Saprolegnia Activity and Host Pathogen Interaction in Zebrafish Disease Model

• Published in: Mycobiology 2017, 45(4), , pp.297-311
• Main Authors: Shin, Sangyeop, Kulatunga, D C M, Dananjaya, S H S, Nikapitiya, Chamilani, Lee, Jehee, De Zoysa, Mahanama
• Format: Article
• Language: English
• Subjects: 생물학
• ISSN: 1229-8093; 2092-9323
• DOI: 10.5941/MYCO.2017.45.4.297

Saprolegniasis is one of the most devastating oomycete diseases in freshwater fish which is caused by species in the genus including . In this study, we isolated the strain of from diseased rainbow trout in Korea. Morphological and molecular based identification confirmed that isolated oomycete belongs to the member of , supported by its typical features including cotton-like mycelium, zoospores and phylogenetic analysis with internal transcribed spacer region. Pathogenicity of isolated was developed in embryo, juvenile, and adult zebrafish as a disease model. Host-pathogen interaction in adult zebrafish was investigated at transcriptional level. Upon infection with , pathogen/antigen recognition and signaling (TLR2, TLR4b, TLR5b, NOD1, and major histocompatibility complex class I), pro/anti-inflammatory cytokines (interleukin [IL]-1β, tumor necrosis factor α, IL-6, IL-8, interferon γ, IL-12, and IL-10), matrix metalloproteinase (MMP9 and MMP13), cell surface molecules (CD8 and CD4 ) and antioxidant enzymes (superoxide dismutase, catalase) related genes were differentially modulated at 3- and 12-hr post infection. As an anti- agent, plant based lawsone was applied to investigate on the susceptibility of showing the minimum inhibitory concentration and percentage inhibition of radial growth as 200 μg/mL and 31.8%, respectively. Moreover, natural lawsone changed the membrane permeability of mycelium and caused irreversible damage and disintegration to the cellular membranes of . Transcriptional responses of the genes of mycelium exposed to lawsone were altered, indicating that lawsone could be a potential anti- agent for controlling infection.