Rainbow trout from 23 families were evaluated for growth and resistance to the bacterial coldwater disease (BCWD) caused by Flavobacterium psychrophilum and infectious haematopoietic necrosis (IHN) caused by IHN virus. Average family weights were between 161 and 263 g with an average of 225 g at 213 days post‐fertilization with specific growth rates ranging from 2.37 to 2.88. Per cent survival of fish challenged with F. psychr...

To further enhance our understanding of immunological gene expression in rainbow trout, Oncorhynchus mykiss , after infection with naturally occurring pathogens, a series of probes and primers were developed for the quantification of immune factors. Separate groups of specific‐pathogen‐free rainbow trout were infected with either Flavobacterium psychrophilum , Aeromonas salmonicida or infectious haematopoietic necrosis virus (...

A quantitative polymerase chain reaction (QPCR) assay has been developed to detect varying levels of Renibacterium salmoninarum , the causative agent of bacterial kidney disease. This assay allows for the direct enumeration of bacterial DNA or RNA copy number within tissues and body fluids. The assay can be applied non‐lethally and can be used to determine whether R. salmoninarum is transcriptionally active. The presence of R....

The efficacy of adenoviral vectors for gene delivery into fish cells, both in vitro and in vivo , was evaluated. Vectors utilized were of human adenovirus serotype 5 (Ad), which are commonly used in human clinical trials, but have not been assessed for gene delivery to fish. Because nothing is known about Ad receptors in fish, both an Ad (Ad5Luc1) with natural tropism for the coxsackie and adenovirus receptor (CAR), as well as...

To assess the risk of transmission of infectious haematopoietic necrosis virus (IHNV) associated with the movement of processed rainbow trout, Oncorhynchus mykiss , from an area where the virus is endemic, 240 freshly eviscerated fish (225–500 g) exhibiting spinal curvature or spinal compression types of deformities were tested for IHNV by virus isolation and polymerase chain reaction (PCR) techniques. Commercially produced ra...

The rapid identification and quantification of virus in diseased fish is a goal both conservationists and commercial aquaculturists have struggled to attain. Recently a technique for the detection of viral mRNA particles that uses fluorescent tagging and amplification has been developed. Utilizing primers and fluorescent labelled probes generated for the specific identification of the nucleocapsid (N) and glycoprotein (G) gene...