Blar i Faculty of Mathematics and Natural Sciences på forfatter "Colquhoun, Duncan John"
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Biogeography of the fish pathogen Aeromonas salmonicida inferred by vapA genotyping
Gulla, Snorre; Bayliss, Sion; Björnsdóttir, Bryndís; Dalsgaard, Inger; Haenen, Olga; Jansson, Eva; McCarthy, Una; Scholz, Felix; Vercauteren, Maaike; Verner-Jeffreys, David; Welch, Tim; Wiklund, Tom; Colquhoun, Duncan John (Peer reviewed; Journal article, 2019-04-12)A recently described typing system based on sequence variation in the virulence array protein (vapA) gene, encoding the A-layer surface protein array, allows unambiguous subtyping of Aeromonas salmonicida. In the present ... -
Biotyping reveals loss of motility in two distinct Yersinia ruckeri lineages exclusive to Norwegian aquaculture
Riborg, Andreas Ekroll; Colquhoun, Duncan John; Gulla, Snorre (Journal article; Peer reviewed, 2022)Non-motile strains of Yersinia ruckeri, known as Y. ruckeri biotype 2, now dominate amongst clinical isolates retrieved from rainbow trout internationally. Due to an acute increase in the number of yersiniosis cases in ... -
The Fish Pathogen "Candidatus Clavichlamydia salmonicola" - A Missing Link in the Evolution of Chlamydial Pathogens of Humans
Collingro, Astrid; Köstlbacher, Stephan; Siegl, Alexander; Toenshoff, Elena R.; Schulz, Frederik; Mitchell, Susan O.; Weinmaier, Thomas; Rattei, Thomas; Colquhoun, Duncan John; Horn, Matthias (Journal article; Peer reviewed, 2023)Chlamydiae like Chlamydia trachomatis and Chlamydia psittaci are well-known human and animal pathogens. Yet, the chlamydiae are a much larger group of evolutionary ancient obligate intracellular bacteria that includes ... -
Genomic analysis of pasteurella atlantica provides insight on its virulence factors and phylogeny and highlights the potential of reverse vaccinology in aquaculture
Ellul, Rebecca Marie; Kalatzis, Panos G.; Frantzen, Cyril Alexander; Haugland, Gyri Teien; Gulla, Snorre; Colquhoun, Duncan John; Middelboe, Mathias; Wergeland, Heidrun Inger; Rønneseth, Anita (Journal article; Peer reviewed, 2021)Pasteurellosis in farmed lumpsuckers, Cyclopterus lumpus, has emerged as a serious disease in Norwegian aquaculture in recent years. Genomic characterization of the causative agent is essential in understanding the biology ... -
Host specificity and clade dependent distribution of putative virulence genes in Moritella viscosa
Karlsen, Christian; Ellingsen, Anette Bauer; Wiik-Nielsen, Christer R.; Winther-Larsen, Hanne C.; Colquhoun, Duncan John; Sørum, Henning (Peer reviewed; Journal article, 2014-12)Moritella viscosa is the aetiological agent of winter-ulcer disease in farmed salmonids in the North Atlantic. Previously, two major (typical and variant) genetic clades have been demonstrated within this bacterial species, ... -
MLVA genotyping of Moritella viscosa reveals serial emergence of novel, host-specific clonal complexes in Norwegian salmon farming
Sørgaard, Martin; Sveinsson, Karoline Overn; Patel, Sonal; Nilsen, Hanne Katrine; Olsen, Anne Berit; Vaagnes, Øyvind; Colquhoun, Duncan John; Gulla, Snorre (Journal article; Peer reviewed, 2023)A Multi-Locus Variable number of tandem repeat Analysis (MLVA) genotyping scheme was developed for the epidemiological study of Moritella viscosa, which causes ‘winter ulcer’ predominantly in sea-reared Atlantic salmon ... -
Multi-locus variable-number tandem-repeat analysis of the fish-pathogenic bacterium Yersinia ruckeri by multiplex PCR and capillary electrophoresis
Gulla, Snorre; Mohammad, Saima; Colquhoun, Duncan John (Peer reviewed; Journal article, 2019-06-17)Yersinia ruckeri is an important pathogen of farmed salmonids worldwide, but simple tools suitable for epizootiological investigations (infection tracing, etc.) of this bacterium have been lacking. A Multi-Locus Variable-number ... -
Multilocus sequence analysis reveals different lineages of Pseudomonas anguilliseptica associated with disease in farmed lumpfish (Cyclopterus lumpus L.)
Mjølnerød, Even Bysveen; Nilsen, Hanne Katrine; Gulla, Snorre; Riborg, Andreas Ekroll; Bottolfsen, Kirsten; Wiklund, Tom; Christiansen, Debes; Romalde López, Jesús Ángel; Scholz, Felix; Colquhoun, Duncan John (Journal article; Peer reviewed, 2021)The bacterium Pseudomonas anguilliseptica has in recent years emerged as a serious threat to production of lumpfish in Norway. Little is known about the population structure of this bacterium despite its association with ... -
Multilocus variable-number tandem-repeat analysis of Yersinia ruckeri confirms the existence of host specificity, geographic endemism, and anthropogenic dissemination of virulent clones
Gulla, Snorre; Barnes, Andrew C.; Welch, Timothy J.; Romalde, Jesús L.; Ryder, David; Ormsby, Michael J.; Carson, Jeremy; Lagesen, Karin; Verner-Jeffreys, David W.; Davies, Robert L.; Colquhoun, Duncan John (Peer reviewed; Journal article, 2018-08)A multilocus variable-number tandem-repeat analysis (MLVA) assay was developed for epizootiological study of the internationally significant fish pathogen Yersinia ruckeri, which causes yersiniosis in salmonids. The assay ... -
Pan-genome survey of the fish pathogen Yersinia ruckeri links accessory- and amplified genes to virulence
Riborg, Andreas Ekroll; Gulla, Snorre; Fiskebeck, Eve Marie Louise Zeyl; Ryder, David; Verner-Jeffreys, David W.; Colquhoun, Duncan John; Welch, Timothy J. (Journal article; Peer reviewed, 2023)While both virulent and putatively avirulent Yersinia ruckeri strains exist in aquaculture environments, the relationship between the distribution of virulence-associated factors and de facto pathogenicity in fish remains ... -
Pharmacokinetic Data Show That Oxolinic Acid and Flumequine Are Absorbed and Excreted Rapidly From Plasma and Tissues of Lumpfish
Haugland, Gyri Teien; Kverme, Karen obrestad; Hannisdal, Rita; Kallekleiv, Marielle; Colquhoun, Duncan John; Lunestad, Bjørn Tore; Wergeland, Heidrun Inger; Samuelsen, Ole Bent (Peer reviewed; Journal article, 2019-11-12)This study examined the uptake, tissue distribution and elimination of the antibacterial agents oxolinic acid and flumequine in lumpfish (Cyclopterus lumpus L.) by use of LC-MS/MS following a single oral administration of ... -
Pharmacokinetics of florfenicol in lumpfish (Cyclopterus lumpus L.) after a single oral administration
Kverme, Karen Obrestad; Haugland, Gyri Teien; Hannisdal, Rita; Kallekleiv, Marielle; Colquhoun, Duncan John; Lunestad, Bjørn Tore; Wergeland, Heidrun Inger; Samuelsen, Ole Bent (Peer reviewed; Journal article, 2019)Farming of lumpfish for biological removal of sea lice from farmed Atlantic salmon has expanded rapidly in Europe and Canada over the last 5–6 years and the lumpfish has become an economically important species. There are, ... -
Phylogeography and host specificity of Pasteurellaceae pathogenic to sea-farmed fish in the north-east Atlantic
Gulla, Snorre; Colquhoun, Duncan John; Olsen, Anne Berit; Spilsberg, Bjørn; Lagesen, Karin; Åkesson, Caroline Piercey; Strøm, Sverri; Manji, Farah; Birkbeck, T.H.; Nilsen, Hanne Katrine (Journal article; Peer reviewed, 2023)The present study was undertaken to address the recent spate of pasteurellosis outbreaks among sea-farmed Atlantic salmon (Salmo salar) in Norway and Scotland, coinciding with sporadic disease episodes in lumpfish (Cyclopterus ... -
qPCR screening for Yersinia ruckeri clonal complex 1 against a background of putatively avirulent strains in Norwegian aquaculture
Riborg, Andreas Ekroll; Gulla, Snorre; Strand, David; Wiik-Nielsen, Jannicke; Rønneseth, Anita; Welch, Timothy J.; Spilsberg, Bjørn; Colquhoun, Duncan John (Journal article; Peer reviewed, 2022)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 ... -
Tenacibaculosis in Norwegian Atlantic salmon (Salmo salar) cage-farmed in cold sea water is primarily associated with Tenacibaculum finnmarkense genomovar finnmarkense
Spilsberg, Bjørn; Nilsen, Hanne Katrine; Tavornpanich, Saraya; Gulla, Snorre; Lagesen, Karin; Jansen, Mona Dverdal; Colquhoun, Duncan John; Olsen, Anne Berit (Journal article; Peer reviewed, 2022)Skin conditions associated with Tenacibaculum spp. constitute a significant threat to the health and welfare of sea-farmed Atlantic salmon (Salmo salar L.) in Norway. Fifteen presumptive tenacibaculosis outbreaks distributed ... -
Vibrio tapetis from wrasse used for ectoparasite bio-control in salmon farming: Phylogenetic analysis and serotyping
Gulla, Snorre; Rønneseth, Anita; Sørum, Henning; Vågnes, Øyvind Brune; Balboa, Sabela; Romalde, Jesús L.; Colquhoun, Duncan John (Peer reviewed; Journal article, 2017-08-09)So-called ‘cleaner fish’, including various wrasse (Labridae) species, have become increasingly popular in Norwegian salmon farming in recent years for biocontrol of the salmon louse Lepeophtheirus salmonis. Cleaner fish ...