Studier av patogenese ved kardiomyopatisyndrom (CMS) hos atlantisk laks, Salmo salar L.

Cardiomyopathy syndrome (CMS) in farmed Atlantic salmon, Salmo salar L., is an infectious viral disease causing severe inflammation in the cardiac spongiosum of atrium and ventricle of the salmonid heart. The disease was first described in 1985 in Norway, and is now wide-spread along the Norwegian coast. CMS usually affects large fish in their last year at sea, hence the economic impact of a moderately increased mortality or outbreaks of CMS with high mortality, is large. Together with salmon lice infestation, CMS is now considered one of the most important problems for Norwegian aquaculture, reflected both in the annual number of diagnoses and the economic losses due to mortality, and is also an increasing problem in other fish farming countries on the northern hemisphere, like Scotland, UK, Ireland and the Faroe Islands. This study was divided into three parts. First, a challenge model for CMS in Atlantic salmon post-smolts was established, then a field outbreak of CMS in a population of young Atlantic salmon was followed until slaughtered and, finally, different methods and sampling material of CMS diagnostics were compared in another challenge trial. Until 2010/2011, the aetiology of the disease was unknown, and several hypothesis excisted, ranging from CMS as a physiological condition, to CMS being caused by environmental factors or to CMS having an infectious, probably viral cause. In this study, we present the results of the first successful experimental trial, confirming the transmissibility of CMS. Unvaccinated post-smolts of Atlantic salmon were intraperitoneally (i.p.) injected with tissue homogenate made of cardiac and kidney tissue of large, farmed Atlantic salmon with CMS, and cardiac lesions in accordance with earlier descriptions of CMS in large, farmed Atlantic salmon developed in the experimental fish. Despite a very long observation period, the prevalence and severity of the cardiac lesions continued, and no indications of healing were observed. In our next study, a population of young Atlantic salmon diagnosed with typical CMS only few months after transferred to sea was followed with several samplings until slaughtered almost 10 months later. The level of PMCV specific RNA was unusually high, and both prevalence and load remained high through the observation period. Cardiac tissue was indisputable the tissue of choice when sampling for detection of PMCV specific RNA in these late, severe stages of CMS, and no difference in load was found between the three sampled compartments atrium, ventricular spongiosum and ventricular compactum. CMS was not diagnosed in any of the other five cages at the site, before 10 weeks after slaughtering of the study cage. The detected PMCV variant was similar to previous sequenced PMCV of Norwegian outbreaks. In the last study, pre-smolt Atlantic salmon were i.p. challenged. Histopathology and real-time RT-PCR results were compared to results of real-time RT-PCR of blood and mucus, of immunohistochemistry (IHC) and of a new RNAscope in situ hybridisation (ISH) method. The results confirmed previous findings of the heart as the organ of choice for virus detection at later time points. Detection of PMCV specific RNA in plasma at early time points is indicating a viremic phase, and mid-kidney also showed a relatively high load at these time points. RNAscope ISH was shown to be both a more sensitive and robust method for in situ detection of PMCV compared to IHC, and be a valuable support to histopathology in CMS diagnostics in early screening and cases of untypical lesions or mixed infections.Kardiomyopatisyndrom (CMS) i atlantisk oppdrettslaks, Salmo salar L., er en infeksiøs virussykdom som forårsaker alvorlig betennelse i laksehjertets indre lag, spongiosum, både i atrium og ventrikkel. Sykdommen ble første gang beskrevet i Norge i 1985, og er nå utbredt langs hele norskekysten. CMS rammer oftest stor laks det siste året de står i sjøen, og moderat økt dødelighet eller CMS-utbrudd gir derfor store økonomiske konsekvenser. Sammen med lakselus, anses CMS nå som en av de viktigste problemene for norsk oppdrettsnæring, noe som gjenspeiles i et høyt antall diagnoser pr. år, og summen av de økonomiske tapene p.g.a. dødelighet. CMS er et økende problem også i andre oppdrettsnasjoner på den nordlige halvkule, som Skottland, resten av Storbritannia, Irland og Færøyene. Denne studien var tredelt. Først ble det etablert en smittemodell for CMS i post-smolt av atlantisk laks, før et feltutbrudd av CMS i ung atlantisk laks ble fulgt tett fram til utslakting av fisken. Til slutt ble prøvemateriale fra et smitteforsøk brukt i en sammenlignende studie av ulike diagnostiske metoder og prøvetyper for CMSdiagnostikk. Fram til 2010/2011 var etiologien til sykdommen ukjent, og flere hypoteser var framsatt, og spente fra CMS som en fysiologisk tilstand, via at CMS var forårsaket av miljøfaktorer til at CMS var en smittsom sykdom, trolig forårsaket av virus. I denne studien presenterer vi resultatene fra det første vellykkete smitteforsøket som viser at CMS er en overførbar sykdom. Uvaksinerte post-smolt av Atlantisk laks ble injisert intraperitonealt (i.p.) med vevshomogenat laget av hjerte- og nyrevev fra stor oppdrettslaks med CMS, og forsøksfisken utviklet hjerteforandringer i tråd med tidligere beskrivelser av CMS i stor oppdrettslaks. Tross en svært lang observasjonsperiode, holdt både prevalens og alvorlighetsgraden av hjertelesjonene seg, og det ble ikke sett tegn på tilheling. I vår neste studie ble en populasjon av ung atlantisk laks diagnostisert med typisk CMS bare få måneder etter sjøsetting, og denne fiskegruppen ble fulgt med flere prøveuttak fram til utslakting nesten 10 måneder senere. Mengden PMCV spesifikt RNA påvist var uvanlig høy, og både prevalens og mengde holdt seg gjennom hele observasjonsperioden. Hjertevev var uten tvil det foretrukne vevet ved prøvetaking for påvisning av PMCV spesifikt RNA i slike sene, alvorlige stadier av CMS, og det ble ikke påvist forskjell i mengde mellom atrium, ventrikkelens spongiosum eller ventrikkelens kompaktum. CMS ble ikke diagnostisert i noen av de fem andre merdene på lokaliteten før en nabomerd fikk en CMS –diagnose 10 uker etter at den undersøkte merden var slaktet ut. PMCV-varianten liknet tidligere sekvenserte PMCV fra norske utbrudd. I den siste studien ble pre-smolt av atlantisk laks smittet i.p.. Histopatologiske og realtime RT-PCR-undersøkelser av vevsprøver ble sammenlignet med resultater fra realtime RT-PCR-undersøkelser av blod og slim, fra immunhistokjemi (IHK) og fra en ny RNAscope in situ hybridiseringsmetode (ISH). Resultatene bekrefter tidligere funn av hjertevev som best egnet for prøvetaking sent i sykdomsforløpet. Påvisning av PMCV spesifikt RNA i plasma i tidlige prøveuttak indikerer en viremisk fase, og det var relativt mye i midt-nyre også på disse tidspunktene. RNAscope ISH-metoden var både mer sensitiv og robust for in situ-påvisning av PMCV enn IHK-metoden, og kan være et verdifullt supplement til histopatologi i CMS-diagnostikk i tidlig-fase screening og i tilfeller med utypiske hjerteforandringer eller blandete infeksjoner.Pharmaq AS ; NV

Pathogenesis studies of cardiomyopathy syndrome (CMS) in Atlantic salmon, Salmo salar L.

Cardiomyopathy syndrome (CMS) in farmed Atlantic salmon, Salmo salar L., is an infectious viral disease causing severe inflammation in the cardiac spongiosum of atrium and ventricle of the salmonid heart. The disease was first described in 1985 in Norway, and is now wide-spread along the Norwegian coast. CMS usually affects large fish in their last year at sea, hence the economic impact of a moderately increased mortality or outbreaks of CMS with high mortality, is large. Together with salmon lice infestation, CMS is now considered one of the most important problems for Norwegian aquaculture, reflected both in the annual number of diagnoses and the economic losses due to mortality, and is also an increasing problem in other fish farming countries on the northern hemisphere, like Scotland, UK, Ireland and the Faroe Islands. This study was divided into three parts. First, a challenge model for CMS in Atlantic salmon post-smolts was established, then a field outbreak of CMS in a population of young Atlantic salmon was followed until slaughtered and, finally, different methods and sampling material of CMS diagnostics were compared in another challenge trial. Until 2010/2011, the aetiology of the disease was unknown, and several hypothesis excisted, ranging from CMS as a physiological condition, to CMS being caused by environmental factors or to CMS having an infectious, probably viral cause. In this study, we present the results of the first successful experimental trial, confirming the transmissibility of CMS. Unvaccinated post-smolts of Atlantic salmon were intraperitoneally (i.p.) injected with tissue homogenate made of cardiac and kidney tissue of large, farmed Atlantic salmon with CMS, and cardiac lesions in accordance with earlier descriptions of CMS in large, farmed Atlantic salmon developed in the experimental fish. Despite a very long observation period, the prevalence and severity of the cardiac lesions continued, and no indications of healing were observed. In our next study, a population of young Atlantic salmon diagnosed with typical CMS only few months after transferred to sea was followed with several samplings until slaughtered almost 10 months later. The level of PMCV specific RNA was unusually high, and both prevalence and load remained high through the observation period. Cardiac tissue was indisputable the tissue of choice when sampling for detection of PMCV specific RNA in these late, severe stages of CMS, and no difference in load was found between the three sampled compartments atrium, ventricular spongiosum and ventricular compactum. CMS was not diagnosed in any of the other five cages at the site, before 10 weeks after slaughtering of the study cage. The detected PMCV variant was similar to previous sequenced PMCV of Norwegian outbreaks. In the last study, pre-smolt Atlantic salmon were i.p. challenged. Histopathology and real-time RT-PCR results were compared to results of real-time RT-PCR of blood and mucus, of immunohistochemistry (IHC) and of a new RNAscope in situ hybridisation (ISH) method. The results confirmed previous findings of the heart as the organ of choice for virus detection at later time points. Detection of PMCV specific RNA in plasma at early time points is indicating a viremic phase, and mid-kidney also showed a relatively high load at these time points. RNAscope ISH was shown to be both a more sensitive and robust method for in situ detection of PMCV compared to IHC, and be a valuable support to histopathology in CMS diagnostics in early screening and cases of untypical lesions or mixed infections

Cardiomyopathy syndrome in Atlantic salmon Salmo salar L.: A review of the current state of knowledge

publishedVersio

Cardiomyopathy syndrome in Atlantic salmon Salmo salar L.: A review of the current state of knowledge

publishedVersio

The chemokine receptor CXCR4 promotes granuloma formation by sustaining a mycobacteria-induced angiogenesis programme

CXC chemokine receptor 4 plays a critical role in chemotaxis and leukocyte differentiation. Furthermore, there is increasing evidence that links this receptor to angiogenesis. Using the well-established zebrafish-Mycobacterium marinum model for tuberculosis, angiogenesis was recently found to be important for the development of cellular aggregates called granulomas that contain the mycobacteria and are the hallmark of tuberculosis disease. Here, we found that initiation of the granuloma-associated proangiogenic programme requires CXCR4 signalling. The nascent granulomas in cxcr4b-deficient zebrafish embryos were poorly vascularised, which in turn also delayed bacterial growth. Suppressed infection expansion in cxcr4b mutants could not be attributed to an overall deficient recruitment of leukocytes or to different intramacrophage bacterial growth rate, as cxcr4b mutants displayed similar microbicidal capabilities against initial mycobacterial infection and the cellular composition of granulomatous lesions was similar to wildtype siblings. Expression of vegfaa was upregulated to a similar extent in cxcr4b mutants and wildtypes, suggesting that the granuloma vascularisation phenotype of cxcr4b mutants is independent of vascular endothelial growth factor

Additional file 8: of De novo assembly of Sockeye salmon kidney transcriptomes reveal a limited early response to piscine reovirus with or without infectious hematopoietic necrosis virus superinfection

Putative DEGs identified by preliminary DESeq and edgeR analysis and subsequent qPCR validation. (PDF 1454 kb

Additional file 6: of De novo assembly of Sockeye salmon kidney transcriptomes reveal a limited early response to piscine reovirus with or without infectious hematopoietic necrosis virus superinfection

Associated UniProt 2013_11 protein database annotation of all Sockey salmon head kidney unigene components. (RAR 14953 kb