qPCR screening for Yersinia ruckeri clonal complex 1 against a background of putatively avirulent strains in Norwegian aquaculture.

Although a number of genetically diverse Yersinia ruckeri strains are present in Norwegian aquaculture environments, most if not all outbreaks of yersiniosis in Atlantic salmon in Norway are associated with a single specific genetic lineage of serotype O1, termed clonal complex 1. To investigate the presence and spread of virulent and putatively avirulent strains in Norwegian salmon farms, PCR assays specific for Y. ruckeri (species level) and Y.

Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease.

This study examines the potential implications of biofouling management on the development of an infectious disease in Norwegian farmed salmon. The hydroid Ectopleura larynx frequently colonises cage nets at high densities (thousands of colonies per m2) and is released into the water during regular in-situ net cleaning. Contact with the hydroids' nematocysts has the potential to cause irritation and pathological damage to salmon gills.

The mycobiota of the production environments of traditional Norwegian salted and dried mutton (pinnekjøtt).

In 2013, mould growth on Norwegian ready-to-sell pinnekjøtt (dried and cured lamb ribs) lead to the withdrawal of 200 tons of the product. The aim of this study was to identify the mycobiota at two Norwegian production sites and determine which species present the highest risk for reduced product quality and safety. A total of 485 samples from 2014, 2015 and 2016 were analysed for Penicillium and Aspergillus species.

Substitution of dietary fish oil with plant oils is associated with shortened mid intestinal folds in Atlantic salmon (Salmo salar).

Background: Fish meal and fish oil are increasingly replaced by ingredients from terrestrial sources in the feeds for farmed salmonids due to expanding production and reduced availability of marine feed raw material. Fish oil that is rich in n-3 polyunsaturated fatty acids is considered beneficial to human health in general and to prevent intestinal inflammation and carcinogenesis in particular. In contrast, n-6 fatty acids that are present in many vegetable oils have been associated with increased risk of colitis and colon cancer in rodents and humans, as well as lowered transcription levels of certain stress and antioxidant-related genes in Atlantic salmon.

First detection of piscine reovirus (PRV) in marine fish species.

Heart and skeletal muscle inflammation (HSMI) is a disease that affects farmed Atlantic salmon Salmo salar L. several months after the fish have been transferred to seawater. Recently, a new virus called piscine reovirus (PRV) was identified in Atlantic salmon from an outbreak of HSMI and in experimentally challenged fish.

A novel totivirus and piscine reovirus (PRV) in Atlantic salmon (Salmo salar) with cardiomyopathy syndrome (CMS).

Background: Cardiomyopathy syndrome (CMS) is a severe disease affecting large farmed Atlantic salmon. Mortality often appears without prior clinical signs, typically shortly prior to slaughter. We recently reported the finding and the complete genomic sequence of a novel piscine reovirus (PRV), which is associated with another cardiac disease in Atlantic salmon; heart and skeletal muscle inflammation (HSMI).

Agar culture of Piscirickettsia salmonis, a serious pathogen of farmed salmonid and marine fish.

Piscirickettsia salmonis, a serious bacterial pathogen of farmed marine fish, previously considered culturable only in eukaryotic cell-culture systems, was grown for the first time on agar and broth containing enhanced levels of cysteine, thus greatly increasing the potential for isolation, in vitro culture and study of this organism. Virulence towards Atlantic salmon following passage on agar media was retained in a controlled laboratory trial. Of the studied temperatures, optimal growth on agar was observed at 22 degrees C.