Detection of piscine orthoreovirus in farmed rainbow trout from Chile

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Abstract

The Piscine orthoreovirus (PRV), a recent member of the Reoviridae family, is an emerging marine pathogen in Salmonids. Two different strains have been described, one of them PRV-Ss is associated with the highly prevalent disease in Atlantic salmon (Salmo salar) known as Heart and Skeletal Muscle Inflammation (HSMI), while the other, PRV-Om, is associated to HSMI-like disease originally described in farmed Rainbow trout from Norway. Genetically, PRV can be classified in the genotypes Ia, Ib and II, being the genotype Ia and Ib associated to PRV-Ss and genotype II to PRV-Om. In Chile, PRV is considered as high-risk marine pathogen but its prevalence on Rainbow trout (wild or farmed) has not been deeply studied. In our lab, heart tissue samples from farmed Rainbow trout mortalities with undefined diagnosis were analyzed in search of viral pathogens. The presence of both PRV-Ss and PRV-Om and absent of other fish viruses was confirmed by RT-qPCR. PRV segment S1 sequences from PRV-Ss and PRV-Om from some representative positive samples were sequenced to determine the genotype and the phylogenetic relationship to PRV strains from different countries and salmonids. The sequences identified in this work are closely related to PRV strains grouped in sub-genotype Ia (Present in Norway – Canada), and the Genotype II. We identifying also one sequence not grouped in any previously described cluster, but close to PRV-Ss from genotype Ib suggesting the presence of a new branch in Genotype I. This analysis also shows that the PRV sequences identified in Rainbow trout are closed related to sequences previously reported in Coho salmon from in Chilean farming centers. Our results suggest that in Chile, Rainbow trout can be infected by different PRVs strains (PRV-Ss and PRV-Om) related mainly to the PRV strains present in Coho salmon. This study is at our knowledge the first description of PRV-Ss and PRV-Om sequences in farmed Rainbow trout from Chile. © 2018 Elsevier B.V.
LanguageEnglish
Pages79-84
Number of pages6
JournalAquaculture
Volume493
DOIs
Publication statusPublished - 2018

Fingerprint

Orthoreovirus
rainbow
Chile
Oncorhynchus mykiss
genotype
pathogen
Oncorhynchus kisutch
heart
Salmonidae
Salmo salar
Norway
skeletal muscle
pathogens
muscle
inflammation
vertebrate viruses
Reoviridae
detection
virus
farming systems

Keywords

  • Atlantic salmon
  • Heart and skeletal muscle inflammation
  • HSMI
  • Piscine orthoreovirus
  • PRV
  • PRV-Om
  • Rainbow trout
  • RT-qPCR
  • detection method
  • disease prevalence
  • genotype
  • mortality
  • pathogen
  • phylogenetics
  • polymerase chain reaction
  • salmonid
  • virus
  • Chile
  • Norway
  • Oncorhynchus kisutch
  • Oncorhynchus mykiss
  • Orthoreovirus
  • Pisces
  • Reoviridae
  • Salmo salar
  • Salmonidae
  • Suid herpesvirus 1

Cite this

@article{22497321f14e4215871d60e4226291ca,
title = "Detection of piscine orthoreovirus in farmed rainbow trout from Chile",
abstract = "The Piscine orthoreovirus (PRV), a recent member of the Reoviridae family, is an emerging marine pathogen in Salmonids. Two different strains have been described, one of them PRV-Ss is associated with the highly prevalent disease in Atlantic salmon (Salmo salar) known as Heart and Skeletal Muscle Inflammation (HSMI), while the other, PRV-Om, is associated to HSMI-like disease originally described in farmed Rainbow trout from Norway. Genetically, PRV can be classified in the genotypes Ia, Ib and II, being the genotype Ia and Ib associated to PRV-Ss and genotype II to PRV-Om. In Chile, PRV is considered as high-risk marine pathogen but its prevalence on Rainbow trout (wild or farmed) has not been deeply studied. In our lab, heart tissue samples from farmed Rainbow trout mortalities with undefined diagnosis were analyzed in search of viral pathogens. The presence of both PRV-Ss and PRV-Om and absent of other fish viruses was confirmed by RT-qPCR. PRV segment S1 sequences from PRV-Ss and PRV-Om from some representative positive samples were sequenced to determine the genotype and the phylogenetic relationship to PRV strains from different countries and salmonids. The sequences identified in this work are closely related to PRV strains grouped in sub-genotype Ia (Present in Norway – Canada), and the Genotype II. We identifying also one sequence not grouped in any previously described cluster, but close to PRV-Ss from genotype Ib suggesting the presence of a new branch in Genotype I. This analysis also shows that the PRV sequences identified in Rainbow trout are closed related to sequences previously reported in Coho salmon from in Chilean farming centers. Our results suggest that in Chile, Rainbow trout can be infected by different PRVs strains (PRV-Ss and PRV-Om) related mainly to the PRV strains present in Coho salmon. This study is at our knowledge the first description of PRV-Ss and PRV-Om sequences in farmed Rainbow trout from Chile. {\circledC} 2018 Elsevier B.V.",
keywords = "Atlantic salmon, Heart and skeletal muscle inflammation, HSMI, Piscine orthoreovirus, PRV, PRV-Om, Rainbow trout, RT-qPCR, detection method, disease prevalence, genotype, mortality, pathogen, phylogenetics, polymerase chain reaction, salmonid, virus, Chile, Norway, Oncorhynchus kisutch, Oncorhynchus mykiss, Orthoreovirus, Pisces, Reoviridae, Salmo salar, Salmonidae, Suid herpesvirus 1",
author = "J. Cartagena and C. Tambley and A.M. Sandino and M. Tello and {Sandino Garcia}, {Ana M.} and {Sandino Garcia}, {Ana M.} and {Spencer Ossa}, {Eugenio G.} and {Spencer Ossa}, {Eugenio G.} and {Tello Reyes}, {Mario C.}",
note = "Export Date: 13 June 2018 CODEN: AQCLA Correspondence Address: Tello, M.; Laboratorio de Metagen{\'o}mica Bacteriana, Centro de Biotecnolog{\'i}a Acu{\'i}cola (CBA), Facultad de Qu{\'i}mica y Biolog{\'i}a, Universidad de Santiago de Chile, Alameda 3363, Estaci{\'o}n Central, Chile; email: mario.tello@usach.cl Funding details: CORFO 13CTI-21527 Funding text: This work was supported by the Proyecto CORFO 13CTI-21527 , and with the support of Salmones Blumar S.A. and Ventisqueros S.A. References: Bustos, P., Rosas, M., Bohle, H., Ildefonso, R., Sandoval, A., Gaete, A., Araya, C., G{\'a}lvez, C., Primer reporte de piscine reovirus en Salm{\'o}n del Atl{\'a}ntico (Salmo salar), cultivado en Chile (2011) Versi{\'o}n Difer., 15, pp. 65-68; Cartagena, J., Tambley, C., Sandino, A.M., Spencer, E., Tello, M., Detection of a Virus Related to Piscine Orthoreovirus (PRV) in O. mykiss Affected by Idiopathic Syndrome of Rainblw Trout (ISRT) [WWW Document]. Database:GeneBank (2016), https://www.ncbi.nlm.nih.gov/nuccore/KX844958.1; Di Cicco, E., Ferguson, H.W., Schulze, A.D., Kaukinen, K.H., Li, S., Vanderstichel, R., Wessel, {\O}., Miller, K.M., Heart and skeletal muscle inflammation (HSMI) disease diagnosed on a British Columbia salmon farm through a longitudinal farm study (2017) PLoS One, 12; Duncan, R., Extensive sequence divergence and phylogenetic relationships between the fusogenic and nonfusogenic orthoreoviruses: a species proposal (1999) Virology, 260, pp. 316-328; Felsenstein, J., Confidence limits on phylogenies: an approach using the bootstrap (1985) Evolution (N. Y), 39, p. 783; Ferguson, H.W., Kongtorp, R.T., Taksdal, T., Graham, D., Falk, K., An outbreak of disease resembling heart and skeletal muscle inflammation in Scottish farmed salmon, Salmo salar L., with observations on myocardial regeneration (2005) J. Fish Dis., 28, pp. 119-123; Godoy, M., Kibenge, M., Wang, Y., Suarez, R., Leiva, C., Vallejos, F., Kibenge, F., First description of clinical presentation of piscine orthoreovirus (PRV) infections in salmonid aquaculture in Chile and identification of a second genotype (Genotype II) of PRV (2016) Virol. J., 13; Hauge, H., Vendramin, N., Taksdal, T., Olsen, A.B., Wessel, {\O}., Mikkelsen, S.S., Alencar, A.L.F., Dahle, M.K., Infection experiments with novel piscine orthoreovirus from rainbow trout (Oncorhynchus mykiss) in salmonids (2017) PLoS One, 12; Kibenge, F., G{\'a}rate, O., Johnson, G., Arriagada, R., Kibenge, M., Wadowska, D., Isolation and identification of infectious salmon anaemia virus (ISAV) from Coho salmon in Chile (2001) Dis. Aquat. Org., 45, pp. 9-18; Kibenge, M., Iwamoto, T., Wang, Y., Morton, A., Godoy, M., Kibenge, F.S., Whole-genome analysis of piscine reovirus (PRV) shows PRV represents a new genus in family Reoviridae and its genome segment S1 sequences group it into two separate sub-genotypes (2013) Virol. J., 10, p. 230; Kongtorp, R., Kjerstad, A., Taksdal, T., Guttvik, A., Falk, K., Heart and skeletal muscle inflammation in Atlantic salmon, Salmo salar L.: a new infectious disease (2004) J. Fish Dis., 27, pp. 351-358; Kongtorp, R., Taksdal, T., Lyng{\o}y, A., Pathology of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon Salmo salar (2004) Dis. Aquat. Org., 59, pp. 217-224; Kongtorp, R.-T., Halse, M., Taksdal, T., Falk, K., Longitudinal study of a natural outbreak of heart and skeletal muscle inflammation in Atlantic salmon, Salmo salar L (2006) J. Fish Dis., 29, pp. 233-244; Kumar, S., Stecher, G., Tamura, K., MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets (2016) Mol. Biol. Evol., 33, pp. 1870-1874; Manr{\'i}quez, R.A., Vera, T., Villalba, M.V., Mancilla, A., Vakharia, V.N., Ya{\~n}ez, A.J., C{\'a}rcamo, J.G., Molecular characterization of infectious pancreatic necrosis virus strains isolated from the three types of salmonids farmed in Chile (2017) Virol. J., 14 (17); MarineHarvest, A., Marine Harvest Annual Report to US Securities and Exchange Commission (2015); Markussen, T., Dahle, M.K., Tengs, T., L{\o}voll, M., Finstad, {\O}.W., Wiik-Nielsen, C.R., Grove, S., Rimstad, E., Sequence analysis of the genome of piscine orthoreovirus (PRV) associated with heart and skeletal muscle inflammation (HSMI) in Atlantic salmon (Salmo salar) (2013) PLoS One, 8; Marty, G.D., Morrison, D.B., Bidulka, J., Joseph, T., Siah, A., Piscine reovirus in wild and farmed salmonids in British Columbia, Canada: 1974-2013 (2015) J. Fish Dis., 38, pp. 713-728; Mikalsen, A.B., Haugland, O., Rode, M., Solbakk, I.T., Evensen, O., Atlantic salmon reovirus infection causes a CD8 T cell myocarditis in Atlantic Salmon (Salmo salar L.) (2012) PLoS One, 7; Morton, A., Routledge, R., Hrushowy, S., Kibenge, M., Kibenge, F., The effect of exposure to farmed salmon on piscine orthoreovirus infection and fitness in wild Pacific salmon in British Columbia, Canada (2017) PLoS One, 12; OIE, Manual of Diagnostic Tests for Aquatic Animals (2017), Office International des {\'e}pizooties; Olsen, A.B., Hjortaas, M., Tengs, T., Hellberg, H., Johansen, R., First description of a new disease in rainbow trout (Oncorhynchus mykiss (Walbaum)) similar to heart and skeletal muscle inflammation (HSMI) and detection of a gene sequence related to piscine orthoreovirus (PRV) (2015) PLoS One, 10; Palacios, G., Lovoll, M., Tengs, T., Hornig, M., Hutchison, S., Hui, J., Kongtorp, R.-T., Lipkin, W.I., Heart and skeletal muscle inflammation of farmed Salmon is associated with infection with a novel reovirus (2010) PLoS One, 5; Saitou, N., Nei, M., The neighbor-joining method: a new method for reconstructing phylogenetic trees (1987) Mol. Biol. Evol., 4, pp. 406-425; SERNAPESCA, Informe Sanitario de Salmonicultura en Centros Marinos 2015 (2016), (Santiago); Subpesca, Informe Sectorial de Pesca y Acuicultura (2016), p. 19; Takano, T., Nawata, A., Sakai, T., Matsuyama, T., Ito, T., Kurita, J., Terashima, S., Nakayasu, C., Full-genome sequencing and confirmation of the causative agent of erythrocytic inclusion body syndrome in Coho Salmon identifies a new type of piscine orthoreovirus (2016) PLoS One, 11; Tamura, K., Nei, M., Kumar, S., Prospects for inferring very large phylogenies by using the neighbor-joining method (2004) Proc. Natl. Acad. Sci. U. S. A., 101, pp. 11030-11035; Wenske, E.A., Chanock, S.J., Krata, L., Fields, B.N., Genetic reassortment of mammalian reoviruses in mice (1985) J. Virol., 56, pp. 613-616; Wessel, {\O}., Olsen, C.M., Rimstad, E., Dahle, M.K., Piscine orthoreovirus (PRV) replicates in Atlantic salmon (Salmo salar L.) erythrocytes ex vivo (2015) Vet. Res., 46, p. 26; Wessel, {\O}., Braaen, S., Alarcon, M., Haatveit, H., Roos, N., Markussen, T., Tengs, T., Rimstad, E., Infection with purified piscine orthoreovirus demonstrates a causal relationship with heart and skeletal muscle inflammation in Atlantic salmon (2017) PLoS One, 12; Zuckerkandl, E., Pauling, L., Evolutionary divergence and convergence in proteins (1965) Evolving Genes and Proteins, pp. 97-166",
year = "2018",
doi = "10.1016/j.aquaculture.2018.04.044",
language = "English",
volume = "493",
pages = "79--84",
journal = "Aquaculture",
issn = "0044-8486",
publisher = "Elsevier Science B.V.",

}

TY - JOUR

T1 - Detection of piscine orthoreovirus in farmed rainbow trout from Chile

AU - Cartagena, J.

AU - Tambley, C.

AU - Sandino, A.M.

AU - Tello, M.

AU - Sandino Garcia, Ana M.

AU - Sandino Garcia, Ana M.

AU - Spencer Ossa, Eugenio G.

AU - Spencer Ossa, Eugenio G.

AU - Tello Reyes, Mario C.

N1 - Export Date: 13 June 2018 CODEN: AQCLA Correspondence Address: Tello, M.; Laboratorio de Metagenómica Bacteriana, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Estación Central, Chile; email: mario.tello@usach.cl Funding details: CORFO 13CTI-21527 Funding text: This work was supported by the Proyecto CORFO 13CTI-21527 , and with the support of Salmones Blumar S.A. and Ventisqueros S.A. References: Bustos, P., Rosas, M., Bohle, H., Ildefonso, R., Sandoval, A., Gaete, A., Araya, C., Gálvez, C., Primer reporte de piscine reovirus en Salmón del Atlántico (Salmo salar), cultivado en Chile (2011) Versión Difer., 15, pp. 65-68; Cartagena, J., Tambley, C., Sandino, A.M., Spencer, E., Tello, M., Detection of a Virus Related to Piscine Orthoreovirus (PRV) in O. mykiss Affected by Idiopathic Syndrome of Rainblw Trout (ISRT) [WWW Document]. Database:GeneBank (2016), https://www.ncbi.nlm.nih.gov/nuccore/KX844958.1; Di Cicco, E., Ferguson, H.W., Schulze, A.D., Kaukinen, K.H., Li, S., Vanderstichel, R., Wessel, Ø., Miller, K.M., Heart and skeletal muscle inflammation (HSMI) disease diagnosed on a British Columbia salmon farm through a longitudinal farm study (2017) PLoS One, 12; Duncan, R., Extensive sequence divergence and phylogenetic relationships between the fusogenic and nonfusogenic orthoreoviruses: a species proposal (1999) Virology, 260, pp. 316-328; Felsenstein, J., Confidence limits on phylogenies: an approach using the bootstrap (1985) Evolution (N. Y), 39, p. 783; Ferguson, H.W., Kongtorp, R.T., Taksdal, T., Graham, D., Falk, K., An outbreak of disease resembling heart and skeletal muscle inflammation in Scottish farmed salmon, Salmo salar L., with observations on myocardial regeneration (2005) J. Fish Dis., 28, pp. 119-123; Godoy, M., Kibenge, M., Wang, Y., Suarez, R., Leiva, C., Vallejos, F., Kibenge, F., First description of clinical presentation of piscine orthoreovirus (PRV) infections in salmonid aquaculture in Chile and identification of a second genotype (Genotype II) of PRV (2016) Virol. J., 13; Hauge, H., Vendramin, N., Taksdal, T., Olsen, A.B., Wessel, Ø., Mikkelsen, S.S., Alencar, A.L.F., Dahle, M.K., Infection experiments with novel piscine orthoreovirus from rainbow trout (Oncorhynchus mykiss) in salmonids (2017) PLoS One, 12; Kibenge, F., Gárate, O., Johnson, G., Arriagada, R., Kibenge, M., Wadowska, D., Isolation and identification of infectious salmon anaemia virus (ISAV) from Coho salmon in Chile (2001) Dis. Aquat. Org., 45, pp. 9-18; Kibenge, M., Iwamoto, T., Wang, Y., Morton, A., Godoy, M., Kibenge, F.S., Whole-genome analysis of piscine reovirus (PRV) shows PRV represents a new genus in family Reoviridae and its genome segment S1 sequences group it into two separate sub-genotypes (2013) Virol. J., 10, p. 230; Kongtorp, R., Kjerstad, A., Taksdal, T., Guttvik, A., Falk, K., Heart and skeletal muscle inflammation in Atlantic salmon, Salmo salar L.: a new infectious disease (2004) J. Fish Dis., 27, pp. 351-358; Kongtorp, R., Taksdal, T., Lyngøy, A., Pathology of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon Salmo salar (2004) Dis. Aquat. Org., 59, pp. 217-224; Kongtorp, R.-T., Halse, M., Taksdal, T., Falk, K., Longitudinal study of a natural outbreak of heart and skeletal muscle inflammation in Atlantic salmon, Salmo salar L (2006) J. Fish Dis., 29, pp. 233-244; Kumar, S., Stecher, G., Tamura, K., MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets (2016) Mol. Biol. Evol., 33, pp. 1870-1874; Manríquez, R.A., Vera, T., Villalba, M.V., Mancilla, A., Vakharia, V.N., Yañez, A.J., Cárcamo, J.G., Molecular characterization of infectious pancreatic necrosis virus strains isolated from the three types of salmonids farmed in Chile (2017) Virol. J., 14 (17); MarineHarvest, A., Marine Harvest Annual Report to US Securities and Exchange Commission (2015); Markussen, T., Dahle, M.K., Tengs, T., Løvoll, M., Finstad, Ø.W., Wiik-Nielsen, C.R., Grove, S., Rimstad, E., Sequence analysis of the genome of piscine orthoreovirus (PRV) associated with heart and skeletal muscle inflammation (HSMI) in Atlantic salmon (Salmo salar) (2013) PLoS One, 8; Marty, G.D., Morrison, D.B., Bidulka, J., Joseph, T., Siah, A., Piscine reovirus in wild and farmed salmonids in British Columbia, Canada: 1974-2013 (2015) J. Fish Dis., 38, pp. 713-728; Mikalsen, A.B., Haugland, O., Rode, M., Solbakk, I.T., Evensen, O., Atlantic salmon reovirus infection causes a CD8 T cell myocarditis in Atlantic Salmon (Salmo salar L.) (2012) PLoS One, 7; Morton, A., Routledge, R., Hrushowy, S., Kibenge, M., Kibenge, F., The effect of exposure to farmed salmon on piscine orthoreovirus infection and fitness in wild Pacific salmon in British Columbia, Canada (2017) PLoS One, 12; OIE, Manual of Diagnostic Tests for Aquatic Animals (2017), Office International des épizooties; Olsen, A.B., Hjortaas, M., Tengs, T., Hellberg, H., Johansen, R., First description of a new disease in rainbow trout (Oncorhynchus mykiss (Walbaum)) similar to heart and skeletal muscle inflammation (HSMI) and detection of a gene sequence related to piscine orthoreovirus (PRV) (2015) PLoS One, 10; Palacios, G., Lovoll, M., Tengs, T., Hornig, M., Hutchison, S., Hui, J., Kongtorp, R.-T., Lipkin, W.I., Heart and skeletal muscle inflammation of farmed Salmon is associated with infection with a novel reovirus (2010) PLoS One, 5; Saitou, N., Nei, M., The neighbor-joining method: a new method for reconstructing phylogenetic trees (1987) Mol. Biol. Evol., 4, pp. 406-425; SERNAPESCA, Informe Sanitario de Salmonicultura en Centros Marinos 2015 (2016), (Santiago); Subpesca, Informe Sectorial de Pesca y Acuicultura (2016), p. 19; Takano, T., Nawata, A., Sakai, T., Matsuyama, T., Ito, T., Kurita, J., Terashima, S., Nakayasu, C., Full-genome sequencing and confirmation of the causative agent of erythrocytic inclusion body syndrome in Coho Salmon identifies a new type of piscine orthoreovirus (2016) PLoS One, 11; Tamura, K., Nei, M., Kumar, S., Prospects for inferring very large phylogenies by using the neighbor-joining method (2004) Proc. Natl. Acad. Sci. U. S. A., 101, pp. 11030-11035; Wenske, E.A., Chanock, S.J., Krata, L., Fields, B.N., Genetic reassortment of mammalian reoviruses in mice (1985) J. Virol., 56, pp. 613-616; Wessel, Ø., Olsen, C.M., Rimstad, E., Dahle, M.K., Piscine orthoreovirus (PRV) replicates in Atlantic salmon (Salmo salar L.) erythrocytes ex vivo (2015) Vet. Res., 46, p. 26; Wessel, Ø., Braaen, S., Alarcon, M., Haatveit, H., Roos, N., Markussen, T., Tengs, T., Rimstad, E., Infection with purified piscine orthoreovirus demonstrates a causal relationship with heart and skeletal muscle inflammation in Atlantic salmon (2017) PLoS One, 12; Zuckerkandl, E., Pauling, L., Evolutionary divergence and convergence in proteins (1965) Evolving Genes and Proteins, pp. 97-166

PY - 2018

Y1 - 2018

N2 - The Piscine orthoreovirus (PRV), a recent member of the Reoviridae family, is an emerging marine pathogen in Salmonids. Two different strains have been described, one of them PRV-Ss is associated with the highly prevalent disease in Atlantic salmon (Salmo salar) known as Heart and Skeletal Muscle Inflammation (HSMI), while the other, PRV-Om, is associated to HSMI-like disease originally described in farmed Rainbow trout from Norway. Genetically, PRV can be classified in the genotypes Ia, Ib and II, being the genotype Ia and Ib associated to PRV-Ss and genotype II to PRV-Om. In Chile, PRV is considered as high-risk marine pathogen but its prevalence on Rainbow trout (wild or farmed) has not been deeply studied. In our lab, heart tissue samples from farmed Rainbow trout mortalities with undefined diagnosis were analyzed in search of viral pathogens. The presence of both PRV-Ss and PRV-Om and absent of other fish viruses was confirmed by RT-qPCR. PRV segment S1 sequences from PRV-Ss and PRV-Om from some representative positive samples were sequenced to determine the genotype and the phylogenetic relationship to PRV strains from different countries and salmonids. The sequences identified in this work are closely related to PRV strains grouped in sub-genotype Ia (Present in Norway – Canada), and the Genotype II. We identifying also one sequence not grouped in any previously described cluster, but close to PRV-Ss from genotype Ib suggesting the presence of a new branch in Genotype I. This analysis also shows that the PRV sequences identified in Rainbow trout are closed related to sequences previously reported in Coho salmon from in Chilean farming centers. Our results suggest that in Chile, Rainbow trout can be infected by different PRVs strains (PRV-Ss and PRV-Om) related mainly to the PRV strains present in Coho salmon. This study is at our knowledge the first description of PRV-Ss and PRV-Om sequences in farmed Rainbow trout from Chile. © 2018 Elsevier B.V.

AB - The Piscine orthoreovirus (PRV), a recent member of the Reoviridae family, is an emerging marine pathogen in Salmonids. Two different strains have been described, one of them PRV-Ss is associated with the highly prevalent disease in Atlantic salmon (Salmo salar) known as Heart and Skeletal Muscle Inflammation (HSMI), while the other, PRV-Om, is associated to HSMI-like disease originally described in farmed Rainbow trout from Norway. Genetically, PRV can be classified in the genotypes Ia, Ib and II, being the genotype Ia and Ib associated to PRV-Ss and genotype II to PRV-Om. In Chile, PRV is considered as high-risk marine pathogen but its prevalence on Rainbow trout (wild or farmed) has not been deeply studied. In our lab, heart tissue samples from farmed Rainbow trout mortalities with undefined diagnosis were analyzed in search of viral pathogens. The presence of both PRV-Ss and PRV-Om and absent of other fish viruses was confirmed by RT-qPCR. PRV segment S1 sequences from PRV-Ss and PRV-Om from some representative positive samples were sequenced to determine the genotype and the phylogenetic relationship to PRV strains from different countries and salmonids. The sequences identified in this work are closely related to PRV strains grouped in sub-genotype Ia (Present in Norway – Canada), and the Genotype II. We identifying also one sequence not grouped in any previously described cluster, but close to PRV-Ss from genotype Ib suggesting the presence of a new branch in Genotype I. This analysis also shows that the PRV sequences identified in Rainbow trout are closed related to sequences previously reported in Coho salmon from in Chilean farming centers. Our results suggest that in Chile, Rainbow trout can be infected by different PRVs strains (PRV-Ss and PRV-Om) related mainly to the PRV strains present in Coho salmon. This study is at our knowledge the first description of PRV-Ss and PRV-Om sequences in farmed Rainbow trout from Chile. © 2018 Elsevier B.V.

KW - Atlantic salmon

KW - Heart and skeletal muscle inflammation

KW - HSMI

KW - Piscine orthoreovirus

KW - PRV

KW - PRV-Om

KW - Rainbow trout

KW - RT-qPCR

KW - detection method

KW - disease prevalence

KW - genotype

KW - mortality

KW - pathogen

KW - phylogenetics

KW - polymerase chain reaction

KW - salmonid

KW - virus

KW - Chile

KW - Norway

KW - Oncorhynchus kisutch

KW - Oncorhynchus mykiss

KW - Orthoreovirus

KW - Pisces

KW - Reoviridae

KW - Salmo salar

KW - Salmonidae

KW - Suid herpesvirus 1

U2 - 10.1016/j.aquaculture.2018.04.044

DO - 10.1016/j.aquaculture.2018.04.044

M3 - Article

VL - 493

SP - 79

EP - 84

JO - Aquaculture

T2 - Aquaculture

JF - Aquaculture

SN - 0044-8486

ER -