| survey of pathogens in hatchery chinook salmon with different out-migration histories through the snake and columbia rivers. | the operation of the federal columbia river power system (fcrps) has negatively affected threatened and endangered salmonid populations in the pacific northwest. barging snake river spring chinook salmon oncorhynchus tshawytscha through the fcrps is one effort to mitigate the effect of the hydrosystem on juvenile salmon out-migration. however, little is known about the occurrence and transmission of infectious agents in barged juvenile salmon relative to juvenile salmon that remain in-river to n ... | 2011 | 21834329 |
| infectious haematopoietic necrosis virus genogroup-specific virulence mechanisms in sockeye salmon, oncorhynchus nerka (walbaum), from redfish lake, idaho. | characterization of infectious haematopoietic necrosis virus (ihnv) field isolates from north america has established three main genogroups (u, m and l) that differ in host-specific virulence. in sockeye salmon, oncorhynchus nerka, the u genogroup is highly virulent, whereas the m genogroup is nearly non-pathogenic. in this study, we sought to characterize the virus-host dynamics that contribute to genogroup-specific virulence in a captive stock of sockeye salmon from redfish lake in idaho. juve ... | 2009 | 19486239 |
| in vivo virus growth competition assays demonstrate equal fitness of fish rhabdovirus strains that co-circulate in aquaculture. | a novel virus growth competition assay for determining relative fitness of rna virus variants in vivo has been developed using the fish rhabdovirus, infectious hematopoietic necrosis virus (ihnv), in juvenile rainbow trout (oncorhynchus mykiss). we have conducted assays with ihnv isolates designated b, c, and d, representing the three most common genetic subtypes that co-circulate in idaho trout farm aquaculture. in each assay, groups of 30 fish were immersed in a 1:1 mixture of two genotypes of ... | 2008 | 18703096 |
| two distinct phylogenetic clades of infectious hematopoietic necrosis virus overlap within the columbia river basin. | infectious hematopoietic necrosis virus (ihnv), an aquatic rhabdovirus, causes a highly lethal disease of salmonid fish in north america. to evaluate the genetic diversity of ihnv from throughout the columbia river basin, excluding the hagerman valley, idaho, the sequences of a 303 nt region of the glycoprotein gene (mid-g) of 120 virus isolates were determined. sequence comparisons revealed 30 different sequence types, with a maximum nucleotide diversity of 7.3% (22 mismatches) and an intrapopu ... | 2003 | 13677505 |
| molecular epidemiology of infectious hematopoietic necrosis virus reveals complex virus traffic and evolution within southern idaho aquaculture. | infectious hematopoietic necrosis virus (ihnv) is a rhabdovirus which infects salmon and trout and may cause disease with up to 90% mortality. in the hagerman valley of idaho, ihnv is endemic or epidemic among numerous fish farms and resource mitigation hatcheries. a previous study characterizing the genetic diversity among 84 ihnv isolates at 4 virus-endemic rainbow trout farms indicated that multiple lineages of relatively high diversity co-circulated at these facilities (troyer et al. 2000 j ... | 2003 | 13677504 |
| genetic analyses reveal unusually high diversity of infectious haematopoietic necrosis virus in rainbow trout aquaculture. | infectious haematopoietic necrosis virus (ihnv) is the most significant virus pathogen of salmon and trout in north america. previous studies have shown relatively low genetic diversity of ihnv within large geographical regions. in this study, the genetic heterogeneity of 84 ihnv isolates sampled from rainbow trout (oncorhynchus mykiss) over a 20 year period at four aquaculture facilities within a 12 mile stretch of the snake river in idaho, usa was investigated. the virus isolates were characte ... | 2000 | 11086112 |
| genetic diversity and epidemiology of infectious hematopoietic necrosis virus in alaska. | forty-two infectious hematopoietic necrosis virus (ihnv) isolates from alaska were analyzed using the ribonuclease protection assay (rpa) and nucleotide sequencing. rpa analyses, utilizing 4 probes, n5, n3 (n gene), gf (g gene), and nv (nv gene), determined that the haplotypes of all 3 genes demonstrated a consistent spatial pattern. virus isolates belonging to the most common haplotype groups were distributed throughout alaska, whereas isolates in small haplotype groups were obtained from only ... | 2000 | 10843554 |