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Henning Sørum - One of the best experts on this subject based on the ideXlab platform.
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Cold-water Vibriosis. The current status of knowledge.
Journal of fish diseases, 2016Co-Authors: A Kashulin, Natalya Seredkina, Henning SørumAbstract:The current review for the first time summarizes the findings of the 30 years of research on cold-water Vibriosis (CWV). The diseased caused by AliiVibrio salmonicida (earlier known as Vibrio salmonicida) was for the first time described in 1986 and became one of the most important bacterial diseases in salmon aquaculture. The lack of appropriate vaccine hampered development of Atlantic salmon aquaculture until the late 1980s when a novel vaccine allowed dramatic increase in the Atlantic salmon farming. In December 2007, the genus Vibrio was split into two genera and several bacterial species including V. salmonicida were transferred to genus AliiVibrio. The change of the names create significant difficulties with the designation of the CWV disease agent since its abbreviation A. salmonicida became similar to another well-known salmon pathogen Aeromonas salmonicida (A. salmonicida). The disease was considered as controlled by vaccination, but reappeared at Atlantic salmon farms in 2011, this time affecting vaccinated Atlantic salmon. The current review summarizes the knowledge on pathogenesis, vaccination and treatment of CWV and proposes further directions for studying the disease.
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Expression of Vibrio salmonicida virulence genes and immune response parameters in experimentally challenged Atlantic salmon (Salmo salar L.).
Frontiers in microbiology, 2013Co-Authors: Ane Mohn Bjelland, Aud Kari Fauske, Anh Nguyen, Ingvild Elise Orlien, Ingrid Østgaard, Henning SørumAbstract:The Gram-negative bacterium Vibrio salmonicida is the causative agent of cold-water Vibriosis (CV), a hemorrhagic septicemia that primarily affects farmed Atlantic salmon (Salmo salar L.). The mechanisms of disease development, host specificity and adaptation, as well as the immunogenic properties of V. salmonicida are largely unknown. Therefore, to gain more knowledge on the pathogenesis of CV, 90 Atlantic salmon parr were injected intraperitonellay with 6 x 106 CFU of V. salmonicida LFI1238. Samples from blood and spleen tissue were taken at different time points throughout the challenge for gene expression analysis by two-step reverse transcription quantitative real-time polymerase chain reaction. Out of a panel of six housekeeping genes, accD, gapA and 16S rDNA were found to be the most suitable references for expression analysis in Vibrio salmonicida. The bacterial proliferation during challenge was monitored based on the expression of the 16S rRNA encoding gene. Before day 4, the concentrations of V. salmonicida in blood and spleen tissue demonstrated a lag phase. From day 4, the bacterial proliferation was exponential. The expression profiles of eight genes encoding potential virulence factors of V. salmonicida were studied. Surprisingly, all tested virulence genes were generally highest expressed in broth cultures compared to the in vivo samples. We hypothesize that this general muting of gene expression in vivo may be a strategy for V. salmonicida to hide from the host immune system. To further investigate this hypothesis, the expression profiles of eight genes encoding innate immune factors were analyzed. The results demonstrated a strong and rapid, but short-lasting innate immune response against V. salmonicida. These results suggest that the bacterium possesses mechanisms that inhibit and/or resist the salmon innate immune system until the host becomes exhausted of fighting the on-going and eventually overwhelming infection.
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Reviewed by:
2013Co-Authors: Ane M. Bjell, Henning Sørum, Anh Nguyen, Aud K. Fauske, Ingvild E. Orlien, Ingrid M. Østgaard, David G. Weissbrodt, Eth Zürich, Luigi L. FazioAbstract:doi: 10.3389/fmicb.2013.00401 Expression of Vibrio salmonicida virulence genes and immune response parameters in experimentally challenged Atlantic salmon (Salmo salar L.
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Vibrio salmonicida pathogenesis analyzed by experimental challenge of Atlantic salmon (Salmo salar)
Microbial pathogenesis, 2011Co-Authors: Ane Mohn Bjelland, Renate Johansen, Espen Brudal, Hilde Hansen, Hanne C. Winther-larsen, Henning SørumAbstract:Abstract Cold-water Vibriosis (CV) is a bacterial septicemia of farmed salmonid fish and cod caused by the Gram-negative bacterium Vibrio (AliiVibrio) salmonicida. To study the pathogenesis of this marine pathogen, Atlantic salmon was experimentally infected by immersion challenge with wild type V. salmonicida and the bacterial distribution in different organs was investigated at different time points. V. salmonicida was identified in the blood as early as 2 h after challenge demonstrating a rapid establishment of bacteremia without an initial period of colonization of the host. Two days after immersion challenge, only a few V. salmonicida were identified in the intestines, but the amount increased with time. In prolonged CV cases, V. salmonicida was the dominating bacterium of the gut microbiota causing a release of the pathogen to the water. We hypothesize that V. salmonicida uses the blood volume for proliferation during the infection of the fish and the salmonid intestine as a reservoir that favors survival and transmission. In addition, a motility-deficient V. salmonicida strain led us to investigate the impact of motility in the CV pathogenesis by comparing the virulence properties of the mutant with the wild type LFI1238 strain in both i.p. and immersion challenge experiments. V. salmonicida was shown to be highly dependent on motility to gain access to the fish host. After invasion, motility was no longer required for virulence, but the absence of normal flagellation delayed the disease development.
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Motility and flagellin gene expression in the fish pathogen Vibrio salmonicida: Effects of salinity and temperature
Microbial pathogenesis, 2008Co-Authors: Christian Karlsen, Henning Sørum, Steinar M. Paulsen, Hege Smith Tunsjø, Simone Krinner, Peik Haugen, Nils-peder WillassenAbstract:The success of several Vibrio species, including Vibrio cholerae, Vibrio anguillarum and Vibrio fischeri in colonizing their symbiont, or causing infection is linked to flagella-based motility. It is during early colonization or the initial phase of infection that motility appears to be critical. In this study we used Vibrio salmonicida, a psychrophilic and moderate halophilic bacterium that causes cold-water Vibriosis in seawater-farmed Atlantic salmon (Salmo salar), to study motility and expression of flagellins under salt conditions mimicking the initial and later phases of an infection. Our results, which are based on motility in semi-solid agar, membrane protein proteomics, quantitation of flagellin gene expression, challenge infection of fish, and microscopy, show that V. salmonicida is highly motile, expresses elevated levels of flagellins, and typically contains several polar flagella under salt conditions that are seawater-like. In contrast, V. salmonicida cells are non-motile and express significantly lower levels of flagellins under physiological-like salt conditions.
Trond Ø. Jørgensen - One of the best experts on this subject based on the ideXlab platform.
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Effects of cecropin peptides on bacteria pathogenic to fish
Journal of Fish Diseases, 1999Co-Authors: A. K. Kjuul, Sigrun Espelid, Erika E Bullesbach, Rex A Dunham, Trond Ø. Jørgensen, Gregory W Warr, Olaf B. StyrvoldAbstract:The antibacterial effects of synthetic cecropin B and cecropin P1 were tested against the fish-pathogenic bacteria Vibrio anguillarum, Vibrio salmonicida, Aeromonas salmonicida, Edwardsiella ictaluri and Yersinia ruckeri. Both cecropins were active against all bacteria tested, but the effect was strongly influenced by the growth media used. In brain heart infusion medium, the minimum inhibitory concentrations of cecropin B ranged from 0.3 to 1.3 μm and from 0.3 to 1.0 μm for cecropin P1, except for E. ictaluri, which was noticeably less sensitive to cecropin P1 (61 μm). The present authors have compared the bactericidal activity of these two peptides, showing that the killing rate for the selected bacteria was higher for cecropin B than for cecropin P1. V. anguillarum was the most sensitive to the cecropins, and in the present study, no colony forming units were detected after 4 and 8 min of treatment with cecropin B and P1, respectively. Electron microscopy was performed to document the effect of cecropin on the bacterial surface.
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Tissue localisation and immune responses in Atlantic Salmon, Salmo salar L., after oral administration of Aeromonas salmonicida, Vibrio anguillarum and Vibrio salmonicidia antigens
Fish & Shellfish Immunology, 1994Co-Authors: Jarl Bøgwald, Klara Stensvåg, Tor B. Stuge, Trond Ø. JørgensenAbstract:Abstract The tissue localisation of formalin-killed radioactive labelled Aeromonas salmonicida, Vibrio anguillarum and Vibrio salmonicida delivered orally to Atlantic salmon ( Salmo salar ) was investigated. The bacteria were delivered by intubation directly into the stomach, and binding/uptake of radiolabelled protein antigens in four gut segments (stomach, pylorus, midgut and hindgut) spleen, blood and kidney was recorded over a 7 day period (5, 12, 24, 72 and 168 h). The peak concentrations (cpm) of antigens in stomach, pylorus, midgut and hindgut was at its highest 5, 12, 24 and 48 h after intubation, respectively. Binding/uptake of antigens in the gut was generally higher in starved fish compared to fed fish. Also, the concentrations of specific antibodies in serum, gut and skin mucus after intraperitoneal, oral and anal administration was investigated. Generally, the antisera obtained after intraperitoneal immunisation showed high antibody titres against the homologous antigens whereas no specific antibodies could be demonstrated in serum after oral administration. Although gut mucus contained a low antibody titre after oral administration of A. salmonicida (A-layer positive), no specific antibodies could be demonstrated in skin mucus up to 10 weeks after intraperitoneal, oral or anal administration of this antigen.
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Two serotypes of Vibrio salmonicida isolated from diseased cod (Gadus morhua L.); virulence, immunological studies and vaccination experiments
Fish & Shellfish Immunology, 1992Co-Authors: Merete Bjørgan Schrøder, Sigrun Espelid, Trond Ø. JørgensenAbstract:Vibrio salmonicida is the causative agent of cold water Vibriosis in Atlantic salmon ( Salmo salar ) in Norway and Scotland, and has more recently been isolated from Arcto-Norwegian cod. The present report deals with the serotyping of V. salmonicida isolated from cod, studies on its virulence, immunological properties, and the vaccination against cold water Vibriosis in cod. Using a panel of monoclonal antibodies it was shown that two distinct sero-types of V. salmonicida exist, one of which is serologically identical to the serotype previously isolated from salmon. Vibrio salmonicida was shown by bacterial titration to be much more virulent in salmon as compared to cod, but immune responses determined by production of specific antibodies were negligible in cod compared to similar immunisation of salmon. Although the antibody production in cod was low, an immersion vaccine based on formalin inactivated V. salmonicida elicited 90–100% protection against cold water Vibriosis in this species.
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Antigen processing of Vibrio salmonicida by fish (Salmo salar L.) macrophages in vitro
Fish & Shellfish Immunology, 1992Co-Authors: Sigrun Espelid, Trond Ø. JørgensenAbstract:Macrophages from Atlantic salmon (Salmo salar L.) were cultured in vitro and their ability to phagocytose the fish pathogen Vibrio salmonicida was studied. The intracellular degradation of the pathogen was detected by use of monoclonal antibodies against two different surface components of the bacterium, LPS and a 24 kDa molecule. The bacterium itself and the 24 kDa protein antigen were shown to be highly susceptible to phagocytic digestion compared to the more resistant LPS components of the bacterial membrane, which persisted internally for several weeks. The phagocytic and degradative processes were also shown to be inhibited by the ionophore monensin whereas NH4Cl blocked only the intracellular processing of V. salmonicida.
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Vaccination of Atlantic salmon, Salmo salar L., with particulate lipopolysaccharide antigens from Vibrio salmonicida and Vibrio anguillarum
Fish & Shellfish Immunology, 1992Co-Authors: Jarl Bøgwald, J. Hoffman, K. Stensvg, K. O. Holm, Trond Ø. JørgensenAbstract:Atlantic salmon were vaccinated by intraperitoneal injection of particulate lipopolysaccharide (LPS) antigens of the two fish pathogens Vibrio salmonicida and Vibrio anguillarum . Particulate LPS from V. salmonicida and V. anguillarum serotype 01 failed to demonstrate a protection against disease after intraperitoneal challenge with live bacteria. However, fish vaccinated with particulate LPS preparations from V. anguillarum serotype 02 acquired a high protection and the LPS-protein complex surface layer antigen VS-P1 from V. salmonicida was seen to give a protection which was superior to purified LPS alone. Vaccination with LPS particles modified by precoating with bovine serum albumin or oleic acid resulted in a slightly better protection compared to the unmodified LPS particle.
Yoshio Ezura - One of the best experts on this subject based on the ideXlab platform.
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Vibrio gallicus sp nov isolated from the gut of the french abalone haliotis tuberculata
International Journal of Systematic and Evolutionary Microbiology, 2004Co-Authors: Tomoo Sawabe, Karin Hayashi, Jun Moriwaki, Richard Christen, Fabiano L. Thompson, Jean Swings, Philippe Potin, Yoshio EzuraAbstract:Five alginolytic, facultatively anaerobic, non-motile bacteria were isolated from the gut of the abalone Haliotis tuberculata. Phylogenetic analyses based on 16S rDNA data indicated that these strains are related to Vibrio wodanis, Vibrio salmonicida, Vibrio logei and Vibrio fischeri (but with <97 % 16S rRNA gene sequence similarity). DNA–DNA hybridization and fluorescence amplified fragment length polymorphism fingerprinting demonstrated that the five strains constituted a single species that was different from all currently known Vibrios. The name Vibrio gallicus sp. nov. (type strain, CIP 107863T=LMG 21878T=HT2-1T; DNA G+C content, 43·6–44·3 mol%) is proposed for this novel taxon. Several phenotypic features were disclosed that discriminated V. gallicus from other Vibrio species: V. gallicus can be differentiated from Vibrio halioticoli on the basis of four traits (β-galactosidase test and assimilation of three carbon compounds) and from Vibrio superstes by 16 traits.
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Vibrio gallicus sp. nov., isolated from the gut of the French abalone Haliotis tuberculata.
International journal of systematic and evolutionary microbiology, 2004Co-Authors: Tomoo Sawabe, Karin Hayashi, Jun Moriwaki, Richard Christen, Fabiano L. Thompson, Jean Swings, Philippe Potin, Yoshio EzuraAbstract:Five alginolytic, facultatively anaerobic, non-motile bacteria were isolated from the gut of the abalone Haliotis tuberculata. Phylogenetic analyses based on 16S rDNA data indicated that these strains are related to Vibrio wodanis, Vibrio salmonicida, Vibrio logei and Vibrio fischeri (but with
Nils-peder Willassen - One of the best experts on this subject based on the ideXlab platform.
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Experimental and computational characterization of the ferric uptake regulator from AliiVibrio salmonicida (Vibrio salmonicida)
The Journal of Microbiology, 2010Co-Authors: Hege Lynum Pedersen, Sigrun Espelid, Nils-peder Willassen, Ingar Leiros, Ellen Kristin Riise, Rafi Ahmad, Hanna-kirsti Schrøder Leiros, Stefan Hauglid, Bjøn Olav Brandsdal, Peik HaugenAbstract:The Ferric uptake regulator (Fur) is a global transcription factor that affects expression of bacterial genes in an iron-dependent fashion. Although the Fur protein and its iron-responsive regulon are well studied, there are still important questions that remain to be answered. For example, the consensus Fur binding site also known as the “Fur box” is under debate, and it is still unclear which Fur residues directly interact with the DNA. Our long-term goal is to dissect the biological roles of Fur in the development of the disease cold-water Vibriosis, which is caused by the psychrophilic bacteria AliiVibrio salmonicida (also known as Vibrio salmonicida ). Here, we have used experimental and computational methods to characterise the Fur protein from A. salmonicida (AS-Fur). Electrophoretic mobility shift assays show that AS-Fur binds to the recently proposed Vibrio Fur box consensus in addition to nine promoter regions that contain Fur boxes. Binding appears to be dependent on the number of Fur boxes, and the predicted “strength” of Fur boxes. Finally, structure modeling and molecular dynamics simulations provide new insights into potential AS-Fur-DNA interactions.
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Motility and flagellin gene expression in the fish pathogen Vibrio salmonicida: Effects of salinity and temperature
Microbial pathogenesis, 2008Co-Authors: Christian Karlsen, Henning Sørum, Steinar M. Paulsen, Hege Smith Tunsjø, Simone Krinner, Peik Haugen, Nils-peder WillassenAbstract:The success of several Vibrio species, including Vibrio cholerae, Vibrio anguillarum and Vibrio fischeri in colonizing their symbiont, or causing infection is linked to flagella-based motility. It is during early colonization or the initial phase of infection that motility appears to be critical. In this study we used Vibrio salmonicida, a psychrophilic and moderate halophilic bacterium that causes cold-water Vibriosis in seawater-farmed Atlantic salmon (Salmo salar), to study motility and expression of flagellins under salt conditions mimicking the initial and later phases of an infection. Our results, which are based on motility in semi-solid agar, membrane protein proteomics, quantitation of flagellin gene expression, challenge infection of fish, and microscopy, show that V. salmonicida is highly motile, expresses elevated levels of flagellins, and typically contains several polar flagella under salt conditions that are seawater-like. In contrast, V. salmonicida cells are non-motile and express significantly lower levels of flagellins under physiological-like salt conditions.
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Structural adaptation of endonuclease I from the cold-adapted and halophilic bacterium Vibrio salmonicida.
Acta crystallographica. Section D Biological crystallography, 2008Co-Authors: Bjørn Altermark, Nils-peder Willassen, Elin Moe, Ronny Helland, Arne O. SmalåsAbstract:The crystal structure of the periplasmic/extracellular endonuclease I from Vibrio salmonicida has been solved to 1.5 A resolution and, in comparison to the corresponding endonucleases from V. cholerae and V. vulnificus, serves as a model system for the investigation of the structural determinants involved in the temperature and NaCl adaptation of this enzyme class. The overall fold of the three enzymes is essentially similar, but the V. salmonicida endonuclease displays a significantly more positive surface potential than the other two enzymes owing to the presence of ten more Lys residues. However, if the optimum salt concentrations for the V. salmonicida and V. cholerae enzymes are taken into consideration in the electrostatic surface-potential calculation, the potentials of the two enzymes become surprisingly similar. The higher number of basic residues in the V. salmonicida protein is therefore likely to be a result, at least in part, of adaptation to the more saline habitat of V. salmonicida (seawater) than V. cholerae (brackish water). The hydrophobic core of all three enzymes is almost identical, but the V. salmonicida endonuclease has a slightly lower number of internal hydrogen bonds. This, together with repulsive forces between the basic residues on the protein surface of V. salmonicida endonuclease I and differences in the distribution of salt bridges, probably results in higher flexibility of regions of the V. salmonicida protein. This is likely to influence both the catalytic activity and the stability of the protein.
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Effects of salt on the kinetics and thermodynamic stability of endonuclease I from Vibrio salmonicida and Vibrio cholerae
The FEBS journal, 2008Co-Authors: Laila Niiranen, Arne O. Smalås, Ronny Helland, Bjørn Altermark, Hanna-kirsti S. Leiros, Bjørn Olav Brandsdal, Nils-peder WillassenAbstract:Adaptation to extreme environments affects the stability and catalytic efficiency of enzymes, often endowing them with great industrial potential. We compared the environmental adaptation of the secreted endonuclease I from the cold-adapted marine fish pathogen Vibrio salmonicida (VsEndA) and the human pathogen Vibrio cholerae (VcEndA). Kinetic analysis showed that VsEndA displayed unique halotolerance. It retained a considerable amount of activity from low concentrations to at least 0.6 m NaCl, and was adapted to work at higher salt concentrations than VcEndA by maintaining a low K(m) value and increasing k(cat). In differential scanning calorimetry, salt stabilized both enzymes, but the effect on the calorimetric enthalpy and cooperativity of unfolding was larger for VsEndA, indicating salt dependence. Mutation of DNA binding site residues (VsEndA, Q69N and K71N; VcEndA, N69Q and N71K) affected the kinetic parameters. The VsEndA Q69N mutation also increased the T(m) value, whereas other mutations affected mainly DeltaH(cal). The determined crystal structure of VcEndA N69Q revealed the loss of one hydrogen bond present in native VcEndA, but also the formation of a new hydrogen bond involving residue 69 that could possibly explain the similar T(m) values for native and N69Q-mutated VcEndA. Structural analysis suggested that the stability, catalytic efficiency and salt tolerance of EndA were controlled by small changes in the hydrogen bonding networks and surface electrostatic potential. Our results indicate that endonuclease I adaptation is closely coupled to the conditions of the habitats of natural Vibrio, with VsEndA displaying a remarkable salt tolerance unique amongst the endonucleases characterized so far.
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Uracil-DNA N-glycosylase (UNG) from the marine, psychrophilic bacterium Vibrio salmonicida shows cold adapted features: A comparative analysis to Vibrio cholerae uracil-DNA N-glycosylase
Enzyme and Microbial Technology, 2008Co-Authors: Inger Lin Uttakleiv Ræder, Nils-peder Willassen, Ingar Leiros, Arne O. Smalås, Elin MoeAbstract:Abstract The genes encoding uracil-DNA N -glycosylase (UNG) from the marine, psychrophilic bacterium Vibrio salmonicida and the mesophilic counterpart Vibrio cholerae have been cloned and expressed in Escherichia coli . The purified proteins have been characterized in order to reveal possible cold adapted features of the V. salmonicida UNG (vsUNG) compared to the V. cholerae UNG (vcUNG). Characterization experiments demonstrated that both enzymes possessed the highest activities at pH 7.0–7.5 and at salt concentrations in the range of 25–50 mM NaCl. Temperature optima for activity were determined to approximately 30 °C for vsUNG and 50 °C for vcUNG. Temperature stability of the enzymes was compared at 4 °C and 37 °C, and vsUNG was found to be more temperature labile than vcUNG. Kinetic studies performed at three different temperatures, 15 °C, 22 °C and 37 °C, demonstrated higher catalytic efficiency for vsUNG compared to vcUNG due to lower K M -values. The increased substrate affinity of vsUNG is probably caused by an increased number of positively charged residues in the DNA-binding site of the enzyme compared to vcUNG. Thus, activity and stability measurements reveal typical cold adapted features of vsUNG.
Jarl Bøgwald - One of the best experts on this subject based on the ideXlab platform.
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Structural studies of the O-antigenic oligosaccharide from Vibrio salmonicida strain C2 isolated from Atlantic cod, Gadus morhua L.
Carbohydrate research, 2006Co-Authors: Jarl Bøgwald, James HoffmanAbstract:Abstract We report the chemical structure of the oligosaccharide part of Vibrio salmonicida lipopolysaccharide serotype C2, isolated from Atlantic cod ( Gadus morhua L.). The structure was established by NMR spectroscopy and mass spectrometry. It is concluded that the oligosaccharide has the following structure in which l -α- d -Hep p is l - glycero -α- d - manno -heptopyranose, d -α- d -Hep p is d - glycero -α- d - manno -heptopyranose, α-NonA is 5-acetamidino-7-acetamido-3,5,7,9-tetradeoxy- l - glycero -α- d - galacto -nonulosonic acid, and PEA is phosphoethanolamine.
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Scavenger-receptor-mediated endocytosis of lipopolysaccharide in Atlantic cod (Gadus morhua L.).
The Journal of Experimental Biology, 2001Co-Authors: Tore Seternes, Jarl Bøgwald, James Hoffman, Roy A. Dalmo, Svetlana N. Zykova, Bård SmedsrødAbstract:SUMMARY The mechanism of elimination of blood-borne Vibrio salmonicida lipopolysaccharide (LPS) from Atlantic cod ( Gadus morhua L.) was studied. The anatomical distribution of LPS was determined using both morphological and radiotracing methods. Immunohistochemistry performed on tissue specimens after injection of LPS disclosed that the endocardial endothelial cells (EECs) represented the cellular site of uptake in heart. Co-injection of trace amounts of [ 125 I]LPS together with excess amounts of formaldehyde-treated albumin (FSA), a ligand for the scavenger receptor, significantly inhibited the accumulation of the radiotracer in heart only. Studies on purified monolayer cultures of atrial EECs showed that fluorescein-labelled LPS was taken up in structures reminiscent of endosomal/lysosomal vesicles. Incubation of cultures with [ 125 I]LPS together with excess amounts of FSA, fucoidan and dextran sulphate, molecules known to compete for endocytosis via the scavenger receptor, reduced uptake of the probe by 80 %. Mannan, a ligand for the mannose receptor, did not compete for uptake. Kinetic studies on the uptake and degradation of [ 125 I]LPS in cultured atrial endocardial cells revealed no degradation after 48 h of culture. In conclusion, we have shown that the EECs of cod remove V. salmonicida LPS from the circulation by scavenger-receptor-mediated endocytosis.
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Structural studies of the Vibrio salmonicida lipopolysaccharide.
Carbohydrate research, 1996Co-Authors: Per Edebrink, Per-erik Jansson, Jarl Bøgwald, James HoffmanAbstract:Abstract The oligosaccharide part of the Vibrio salmonicida (strain NCMB 2262) lipopolysaccharide was isolated by mild acid hydrolysis followed by gel-permeation chromatography. The structure was established mainly by methylation analysis, mass spectrometry, and NMR spectroscopy. It is concluded that the oligosaccharide has the following structure, in which l -α- d - Hep p is l -glycero-α- d -manno- heptopyranose , d -α- d -Hepp is d -glycero-α- d -manno-heptopyranose, α- d -Fuc p4 N is 4-amino-4,6-dideoxy-α- d -galactopyranose, α-NonA is 5-acetamidino-7-acetamido-3,5,7,9-tetradeoxy- l - glycero -α- d - galacto -nonulosonic acid, BA is ( R )-3-hydroxybutanoyl, and PEA is phosphoethanolamine. The substitution pattern of the branching heptosyl residue was deduced from 1 H NMR chemical shifts and conformations of the branching region, obtained by molecular modelling. The absolute configuration for NonA was determined by NMR spectroscopy from NOE correlations to the neighbouring sugar and 13 C NMR chemical shift data. It could also be shown that assignments of nonulosonic acids with the d - glycero - l - galacto configuration, reported by previous investigators, are erroneous and should be changed to l - glycero - d - galacto . The oligosaccharide is assumed to be linked to the 5-position of a Kdo residue, phosphorylated in the 4-position as observed for other lipopolysaccharides from Vibrionaceae.
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Tissue localisation and immune responses in Atlantic Salmon, Salmo salar L., after oral administration of Aeromonas salmonicida, Vibrio anguillarum and Vibrio salmonicidia antigens
Fish & Shellfish Immunology, 1994Co-Authors: Jarl Bøgwald, Klara Stensvåg, Tor B. Stuge, Trond Ø. JørgensenAbstract:Abstract The tissue localisation of formalin-killed radioactive labelled Aeromonas salmonicida, Vibrio anguillarum and Vibrio salmonicida delivered orally to Atlantic salmon ( Salmo salar ) was investigated. The bacteria were delivered by intubation directly into the stomach, and binding/uptake of radiolabelled protein antigens in four gut segments (stomach, pylorus, midgut and hindgut) spleen, blood and kidney was recorded over a 7 day period (5, 12, 24, 72 and 168 h). The peak concentrations (cpm) of antigens in stomach, pylorus, midgut and hindgut was at its highest 5, 12, 24 and 48 h after intubation, respectively. Binding/uptake of antigens in the gut was generally higher in starved fish compared to fed fish. Also, the concentrations of specific antibodies in serum, gut and skin mucus after intraperitoneal, oral and anal administration was investigated. Generally, the antisera obtained after intraperitoneal immunisation showed high antibody titres against the homologous antigens whereas no specific antibodies could be demonstrated in serum after oral administration. Although gut mucus contained a low antibody titre after oral administration of A. salmonicida (A-layer positive), no specific antibodies could be demonstrated in skin mucus up to 10 weeks after intraperitoneal, oral or anal administration of this antigen.
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Vaccination of Atlantic salmon, Salmo salar L., with particulate lipopolysaccharide antigens from Vibrio salmonicida and Vibrio anguillarum
Fish & Shellfish Immunology, 1992Co-Authors: Jarl Bøgwald, J. Hoffman, K. Stensvg, K. O. Holm, Trond Ø. JørgensenAbstract:Atlantic salmon were vaccinated by intraperitoneal injection of particulate lipopolysaccharide (LPS) antigens of the two fish pathogens Vibrio salmonicida and Vibrio anguillarum . Particulate LPS from V. salmonicida and V. anguillarum serotype 01 failed to demonstrate a protection against disease after intraperitoneal challenge with live bacteria. However, fish vaccinated with particulate LPS preparations from V. anguillarum serotype 02 acquired a high protection and the LPS-protein complex surface layer antigen VS-P1 from V. salmonicida was seen to give a protection which was superior to purified LPS alone. Vaccination with LPS particles modified by precoating with bovine serum albumin or oleic acid resulted in a slightly better protection compared to the unmodified LPS particle.
