Comparative susceptibilities and immune reactions of wild and cultured populations of Caspian trout Salmo trutta caspius to VHSV

TY - JOUR

T1 - Comparative susceptibilities and immune reactions of wild and cultured populations of Caspian trout Salmo trutta caspius to VHSV

AU - Mohammad Karami, Asma

AU - Bani, Ali

AU - Pourkazemi, Mohammad

AU - Ghasemi, Mohades

AU - Kania, Per Walter

AU - Buchmann, Kurt

PY - 2018

Y1 - 2018

N2 - Caspian trout Salmo trutta caspius is an endangered subspecies of brown trout Salmo trutta which is native to the Caspian Sea. Restocking programmes have been established, but recent introduction of the rhabdovirus viral haemorrhagic septicaemia virus (VHSV) into Iranian rainbow trout farms connected to waterbodies supporting wild Caspian trout may represent an additional threat to the declining stock. The susceptibility of wild and cultured populations of this endemic subspecies was demonstrated by performing controlled VHSV infection experiments (both by bath and injection challenges). Subsequently, VHSV infection in exposed fish was confirmed (CPE and quantitative PCR), virus levels were measured, and regulation of immune genes in exposed fish was investigated with a focus on the genes encoding IL-8, IFNγ, TGFβ, TNFα, SAA, C3-4, CD8α, IgM, MHC I, MHC II, iNOS and IGF-1. The presence of IgM-, CD8α-And MHC II-positive cells in host organs was visualized by immunohistochemistry. Both wild and cultured trout strains proved to be VHSV-susceptible following experimental challenge, but the mortality curves and associated regulation of immune-related genes differed between the 2 trout types. Implications of the results for future management of Caspian trout populations are discussed.

AB - Caspian trout Salmo trutta caspius is an endangered subspecies of brown trout Salmo trutta which is native to the Caspian Sea. Restocking programmes have been established, but recent introduction of the rhabdovirus viral haemorrhagic septicaemia virus (VHSV) into Iranian rainbow trout farms connected to waterbodies supporting wild Caspian trout may represent an additional threat to the declining stock. The susceptibility of wild and cultured populations of this endemic subspecies was demonstrated by performing controlled VHSV infection experiments (both by bath and injection challenges). Subsequently, VHSV infection in exposed fish was confirmed (CPE and quantitative PCR), virus levels were measured, and regulation of immune genes in exposed fish was investigated with a focus on the genes encoding IL-8, IFNγ, TGFβ, TNFα, SAA, C3-4, CD8α, IgM, MHC I, MHC II, iNOS and IGF-1. The presence of IgM-, CD8α-And MHC II-positive cells in host organs was visualized by immunohistochemistry. Both wild and cultured trout strains proved to be VHSV-susceptible following experimental challenge, but the mortality curves and associated regulation of immune-related genes differed between the 2 trout types. Implications of the results for future management of Caspian trout populations are discussed.

KW - Caspian trout

KW - Immunit

KW - Susceptibility

KW - Viral haemorrhagic septicaemia virus

U2 - 10.3354/dao03231

DO - 10.3354/dao03231

M3 - Journal article

C2 - 29862977

AN - SCOPUS:85048320684

SN - 0177-5103

VL - 128

SP - 187

EP - 201

JO - Diseases of Aquatic Organisms

JF - Diseases of Aquatic Organisms

IS - 3

ER -