RESUMO
Pancreas disease (PD), caused by salmonid alphavirus subtype 3 (SAV3), emerged in Norwegian aquaculture in the 1980s and is now endemic along the south-western coast. In 2011, the first cases of PD caused by marine salmonid alphavirus subtype 2 (SAV2) were reported. This subtype has spread rapidly among the fish farms outside the PD-endemic zone and is responsible for disease outbreaks at an increasing numbers of sites. To describe the geographical distribution of salmonid alphavirus (SAV), and to assess the time and site of introduction of marine SAV2 to Norway, an extensive genetic characterization including more than 200 SAV-positive samples from 157 Norwegian marine production sites collected from May 2007 to December 2012 was executed. The first samples positive for marine SAV2 originated from Romsdal, in June 2010. Sequence analysis of the E2 gene revealed that all marine SAV2 included in this study were nearly identical, suggesting a single introduction into Norwegian aquaculture. Further, this study provides evidence of a separate geographical distribution of two subtypes in Norway. SAV3 is present in south-western Norway, and marine SAV2 circulates in north-western and Mid-Norway, a geographical area which since 2010 constitutes the endemic zone for marine SAV2.
Assuntos
Infecções por Alphavirus/veterinária , Alphavirus/genética , Doenças dos Peixes/virologia , Proteínas Virais/genética , Proteínas Virais/metabolismo , Alphavirus/classificação , Infecções por Alphavirus/transmissão , Infecções por Alphavirus/virologia , Animais , Aquicultura , Doenças dos Peixes/transmissão , Tipagem Molecular , Noruega , Filogenia , SalmonidaeRESUMO
BACKGROUND: Gastroschisis (GS) is a congenital abdominal wall defect that results in the development of GS-related intestinal dysfunction (GRID). Transforming growth factor-ß, a pro-inflammatory cytokine, has been shown to cause organ dysfunction through alterations in vascular and airway smooth muscle. The purpose of this study was to evaluate the effects of TGF-ß3 on intestinal smooth muscle function and contractile gene expression. METHODS: Archived human intestinal tissue was analyzed using immunohistochemistry and RT-PCR for TGF-ß isoforms and markers of smooth muscle gene and micro-RNA contractile phenotype. Intestinal motility was measured in neonatal rats ± TGF-ß3 (0.2 and 1 mg/kg). Human intestinal smooth muscle cells (hiSMCs) were incubated with fetal bovine serum ± 100 ng/ml of TGF-ß 3 isoforms for 6, 24 and 72 h. The effects of TGF-ß3 on motility, hiSMC contractility and hiSMC contractile phenotype gene and micro-RNA expression were measured using transit, collagen gel contraction assay and RT-PCR analysis. Data are expressed as mean ± SEM, ANOVA (n = 6-7/group). RESULTS: GS infants had increased immunostaining of TGF-ß3 and elevated levels of micro-RNA 143 & 145 in the intestinal smooth muscle. Rats had significantly decreased intestinal transit when exposed to TGF-ß3 in a dose-dependent manner compared with Sham animals. TGF-ß3 significantly increased hiSMC gel contraction and contractile protein gene and micro-RNA expression. CONCLUSION: TGF-ß3 contributed to intestinal dysfunction at the organ level, increased contraction at the cellular level and elevated contractile gene expression at the molecular level. A hyper-contractile response may play a role in the persistent intestinal dysfunction seen in GRID.
Assuntos
Motilidade Gastrointestinal , Gastrosquise/metabolismo , Mucosa Intestinal/metabolismo , Contração Muscular , Músculo Liso/metabolismo , Miócitos de Músculo Liso/metabolismo , Fator de Crescimento Transformador beta3/metabolismo , Animais , Animais Recém-Nascidos , Células Cultivadas , Relação Dose-Resposta a Droga , Motilidade Gastrointestinal/efeitos dos fármacos , Gastrosquise/genética , Gastrosquise/fisiopatologia , Regulação da Expressão Gênica , Humanos , Lactente , Intestinos/efeitos dos fármacos , Intestinos/fisiopatologia , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiopatologia , Miócitos de Músculo Liso/efeitos dos fármacos , Fenótipo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Fatores de Tempo , Fator de Crescimento Transformador beta3/administração & dosagem , Fator de Crescimento Transformador beta3/genéticaRESUMO
This paper provides supplementary data to the research paper ''Presence and habitats of bacterial fish pathogen relatives in a marine salmon post-smolt RAS" [1]. Here, environmental samples from a marine recirculating aquaculture system (RAS) were subjected to microbiome studies. This data article adds value to the research article by providing open access to data files that increased information retrieval from the 16S rRNA sequence library. A fasta file of full-length 16S rRNA sequences from fish pathogenic microbes was deposited in the Mendeley data repository, a collection named "Fish Pathogen Database". Alignment of this database against the short sequences in the 16S rRNA library revealed the fish pathogen-relatives. Furthermore, a link to a CSV file containing Pearson correlation data was provided, an analysis based on the relative abundance information of all operational taxonomic units defined in the microbiome dataset. Included also, the methodological description of the Pearson correlation analysis, as well as a table where correlation data for the defined fish pathogen-relatives was retrieved from the large data file (Table 1).
Assuntos
Infecções por Alphavirus/veterinária , Alphavirus , Doenças dos Peixes/virologia , Perciformes , Infecções por Alphavirus/transmissão , Animais , Suscetibilidade a Doenças/veterinária , Doenças dos Peixes/transmissão , Pancreatopatias/veterinária , Pancreatopatias/virologia , Salmão/virologiaRESUMO
A marine aquaculture recycling system (RAS) for the production of post-smolt was monitored for microbial community structures during the first year of operation. Sample material was obtained monthly from the biofilter biofilm carriers, the production water (tank 3), the fish skin (tank 3) and the tank 3 wall biofilm. Additional samples were taken during outbreaks of fish skin wounds, washing of the plant, UV filtration of the inlet water and from various wall biofilms. Samples for depth profiles from all fish tanks were also collected. The sampling tools were a ladle for capturing biofilter biofilm carriers, toothbrushes for wall biofilm capture, filters for capture of water microbes and scalpels for skin tissue slicing. The sampling times were indicated by the production cycle number (cycle 2-5) and the week number within the cycle (W). Prior to bacterial community analysis, the stored samples were exposed to cell lysis and extraction of environmental DNA by commercial kits. All samples were subjected for PCR amplification of 16S rDNA sequences for library formations and prepared for Ion Torrent technology, which sequences 250 bp fragments. A total of 1.1 million reads were obtained from the 100 RAS samples analysed. The process from Ion Torren analysis to library involved bioinformatics steps with sorting, filtering, adjustment and taxonomic identification, and the final output was shown in a table as operational taxonomic units (OTUs) and relative abundance at different sampling sites and sampling time points. Of a total of 450 taxonomically assigned OTUs, 45% were classified at genus level. The 16S library raw data are deposited in the Mendeley data repository and cited in this Data in Brief article co-submitted with the article "Microbial colonization and stability in a marine post-smolt RAS inoculated with a commercial starter culture." [1]. So far, the raw data are referenced in four more publications in progress. These cover microbial shifts and enrichments between sampling times, sulfur cycling, "in vivo biofilm" and identification of relatives of fish pathogens in RAS. All library sequences are available in GenBank with accession numbers MN890148-MN891672.
RESUMO
Coldwater-associated ulcers, i.e. winter ulcers, in seawater-reared Atlantic salmon Salmo salar L. have been reported in Norway since the late 1980s, and Moritella viscosa has been established as an important factor in the pathogenesis of this condition. As routine histopathological examination of winter ulcer cases in our laboratory revealed frequent presence in ulcers of long, slender rods clearly different from M. viscosa, a closer study focusing on these bacteria was conducted. Field cases of winter ulcers during 2 sampling periods, 1996 and 2004-2005, were investigated and long, slender rods were observed by histopathological examination in 70 and 62.5% of the ulcers examined, respectively, whereas cultivation on marine agar resulted in the isolation of yellow-pigmented colonies with long rods from 3 and 13% of the ulcers only. The isolates could be separated into 2 groups, both identified as belonging to the genus Tenacibaculum based on phenotypic characterization and 16S rRNA sequencing. Bath challenge for 7 h confirmed the ability of Group 1 bacterium to produce skin and cornea ulcers. In fish already suffering from M. viscosa-induced ulcers, co-infection with the Group 1 bacterium was established within 1 h. Ulcers from field cases of winter ulcers and from the transmission experiments tested positive by immunohistochemistry with polyclonal antiserum against the Group 1 bacterium but not the Group 2 bacterium. Our results strongly indicate the importance of the Group 1 bacterium in the pathogenesis of winter ulcers in Norway. The bacterium is difficult to isolate and is therefore likely to be underdiagnosed based on cultivation only.
Assuntos
Doenças dos Peixes/microbiologia , Infecções por Flavobacteriaceae/veterinária , Flavobacteriaceae/isolamento & purificação , Salmo salar , Úlcera Cutânea/veterinária , Animais , Aquicultura , Oceano Atlântico/epidemiologia , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/patologia , Flavobacteriaceae/genética , Infecções por Flavobacteriaceae/epidemiologia , Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/patologia , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Estações do Ano , Úlcera Cutânea/microbiologiaRESUMO
During the 1980s and 1990s wild-caught cod displaying visceral granulomatosis were sporadically identified from the southern North Sea. Presumptive diagnoses at the time included mycobacterial infection, although mycobacteria were never cultivated or observed histologically from these fish. Farmed cod in Norway displaying gross pathology similar to that identified previously in cod from the southern North Sea were recently discovered to be infected with the bacterium Francisella noatunensis subsp, noatunensis. Archived formalin-fixed paraffin-embedded tissues from the original North Sea cases were investigated for the presence of Mycobacterium spp. and Francisella spp. using real-time polymerase chain reaction, DNA sequencing and immunohistochemistry. Whilst no evidence of mycobacterial infection was found, F. noatunensis subsp. noatunensis was identified in association with pathological changes consistent with Francisella infections described from farmed cod in recent years. This study shows that francisellosis occurred in wild-caught cod in the southern North Sea in the 1980s and 1990s and demonstrates that this disease predates intensive aquaculture of cod.
Assuntos
Doenças dos Peixes/microbiologia , Francisella/genética , Francisella/isolamento & purificação , Granuloma/veterinária , Animais , Oceano Atlântico/epidemiologia , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/patologia , Gadus morhua , Granuloma/microbiologia , Imuno-Histoquímica/métodos , Imuno-Histoquímica/veterinária , Sensibilidade e EspecificidadeRESUMO
Previously undocumented phenotypical and genetic variation was identified amongst isolates of Moritella viscosa collected from various geographical locations and from different fish species. The studied isolates could be split into 2 major phenotypically and genetically different clusters, one of which was consistent with the species type strain (NCIMB 13548). Isolates consistent with the type strain originated exclusively from Atlantic salmon farmed in Norway, Scotland and the Faroe Isles, although a single isolate from farmed Norwegian cod clustered closely with this group. The 'variant' cluster comprised isolates originating from Norwegian farmed rainbow trout, Icelandic farmed rainbow trout and salmon, Canadian farmed (Atlantic) salmon, Icelandic lumpsucker and only exceptionally from Norwegian salmon. With the exception of the single aforementioned cod isolate, all isolates from Norwegian farmed cod belonged to the variant cluster. Phenotypically, the clusters could be absolutely separated only by elevated haemolytic activity in the variant strain, although approximately half of these isolates also produced acid from mannose, in contrast to the typical (type) strain. While 16S rRNA gene sequencing was unable to separate the 2 clusters, Western blot analyses, plasmid profile analysis, pulsed field gel electrophoresis and gyrB gene sequence analysis produced clusters consistent with the phenotypic data. Macroscopically and histologically the disease in rainbow trout caused by the variant strain was consistent with that previously described in Atlantic salmon. The results of the present study may indicate a degree of host specificity of the typical strain for Atlantic salmon.
Assuntos
Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Moritella/classificação , Animais , Aquicultura , Oceano Atlântico/epidemiologia , Canadá/epidemiologia , DNA Girase/genética , DNA Girase/metabolismo , Doenças dos Peixes/epidemiologia , Peixes , Regulação Bacteriana da Expressão Gênica/fisiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Noruega/epidemiologia , Filogeografia , RNA Ribossômico 16S/genéticaRESUMO
A cohort study was initiated in the spring of 2006 to investigate epidemiological aspects and pathogenesis of salmonid alphavirus (SAV) subtype 3 infections and pancreas disease (PD). The aims were to assess involvement of the freshwater production phase, the extent and frequency of subclinical infections and to follow PD-affected populations throughout the entire seawater production cycle, as well as investigate possible risk factors for PD outbreaks. Fish groups from 46 different Atlantic salmon freshwater sites in six counties were sampled once prior to seawater transfer and followed onto their seawater sites. A total of 51 Atlantic salmon seawater sites were included, and fish groups were sampled three times during the seawater production phase. SAV subtype 3 was not identified by real-time RT-PCR from samples collected in the freshwater phase, nor were any SAV-neutralizing antibodies or histopathological changes consistent with PD. In the seawater phase, SAV was detected in samples from 23 of 36 (63.9%) studied sites located within the endemic region. No SAV subtype 3 was detected in samples from seawater sites located outside the endemic region. The cumulative incidence of PD during the production cycle amongst sites with SAV detected was 87% (20 of 23 sites). Average fish weight at time of PD diagnosis ranged from 461 to 5978 g, because of a wide variation in the timing of disease occurrence throughout the production cycle. Mortality levels following a PD diagnosis varied greatly between populations. The mean percentage mortality was 6.9% (+/-7.06) (range 0.7-26.9), while the mean duration of increased mortality following PD diagnosis was 2.8 months (+/-1.11) (range 1-6).
Assuntos
Infecções por Alphavirus/veterinária , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/patologia , Água Doce , Pancreatopatias/veterinária , Água do Mar , Alphavirus , Infecções por Alphavirus/epidemiologia , Infecções por Alphavirus/mortalidade , Infecções por Alphavirus/patologia , Animais , Anticorpos Antivirais/sangue , Estudos de Coortes , Doenças dos Peixes/mortalidade , Doenças dos Peixes/virologia , Incidência , Estimativa de Kaplan-Meier , Noruega , Pancreatopatias/epidemiologia , Pancreatopatias/mortalidade , Pancreatopatias/patologia , Pancreatopatias/virologia , Reação em Cadeia da Polimerase , Prevalência , Fatores de Risco , Salmo salarRESUMO
A prospective longitudinal study was performed on three cages at each of three Norwegian Atlantic salmon seawater sites that experienced outbreaks of pancreas disease (PD). Once salmonid alphavirus (SAV) ribonucleic acid (RNA) was detected by real-time RT-PCR (Rt RT-PCR) at a site, it became detected in all studied cages and was persistently found until the end of the study period up to 19 months after first detection. SAV-specific antibodies were detected at all sites until the end of the study period and were also found at a high prevalence in broodfish at the time of stripping. No evidence of increased viral activity was detected in these broodfish. One site tested negative over several months prior to the first detection of SAV by Rt RT-PCR and SAV-specific antibody, which occurred 1 month prior to clinical manifestations of PD. Moribund fish or thin fish/runts that were sampled after the first PD diagnosis had almost twice the risk of testing positive by one or more diagnostic tests compared to that of randomly selected apparently healthy individuals. This paper describes the first detailed investigation of the disease development of PD at site and cage level in Norway, as well as an assessment of the performance and agreement of the commonly used diagnostic tests.
Assuntos
Doenças dos Peixes/diagnóstico , Doenças dos Peixes/patologia , Pancreatopatias/veterinária , Salmo salar/virologia , Alphavirus/fisiologia , Animais , Anticorpos Antivirais/sangue , Doenças dos Peixes/virologia , Estudos Longitudinais , Noruega , Pancreatopatias/diagnóstico , Pancreatopatias/patologia , Pancreatopatias/virologia , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterináriaRESUMO
Pancreas disease (PD) is an important cause of losses in farmed salmonids in Norway, the United Kingdom and Ireland. As the spread of salmonid alphavirus (SAV), the causal agent, to naïve populations is of major concern to the farming industry, it is important to uncover the transmission routes of the virus. This study was conducted to investigate the potential for vertical transmission of SAV subtype 3. Progeny of broodstock with signs of late-stage PD and persistent RT-PCR signals for SAV were followed from fertilization to smoltification in an experimental facility. Fertilized ova were either not disinfected or taken through one of three different disinfection regimes. Also, ova and milt from uninfected broodfish from a different population were exposed to a cell-cultured strain of SAV 3 immediately before fertilization to simulate a viraemic phase in parent fish. A group of uninfected controls were also included in the study. Fertilized ova from bath exposed and negative control groups were double disinfected. Following fertilization, experimental fish went through a normal freshwater phase. However, fry were stressed at first feeding to enhance replication of possibly latent virus. Smoltification was induced by an artificial light regime, and experimental fish were followed to the late smoltification phase. Selected samples were investigated by real-time RT-PCR for SAV, by histology for evidence of PD and by serology for neutralising antibodies against SAV. All analysed samples of progeny were negative. This result shows that SAV 3 is not readily transmitted vertically from parents to offspring. Additional negative PCR results from salmon sampled in commercial hatcheries support these findings. Also, recent studies have shown that risk factors for the horizontal transmission route explain the vast majority of PD outbreaks in Norway. It is concluded that if it happens at all, vertical transmission is of minor importance in the spread of SAV 3.
Assuntos
Infecções por Alphavirus/veterinária , Alphavirus/fisiologia , Doenças dos Peixes/transmissão , Doenças dos Peixes/virologia , Transmissão Vertical de Doenças Infecciosas/veterinária , Pancreatopatias/veterinária , Salmo salar , Alphavirus/genética , Alphavirus/imunologia , Infecções por Alphavirus/epidemiologia , Infecções por Alphavirus/transmissão , Infecções por Alphavirus/virologia , Animais , Anticorpos Antivirais/sangue , Feminino , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/imunologia , Pesqueiros , Células Germinativas/imunologia , Células Germinativas/virologia , Masculino , Noruega/epidemiologia , Pancreatopatias/epidemiologia , Pancreatopatias/imunologia , Pancreatopatias/virologia , RNA Viral/química , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Água do Mar , Análise de SobrevidaAssuntos
Infecções por Alphavirus/veterinária , Alphavirus/fisiologia , Doenças dos Peixes/diagnóstico , Pancreatopatias/veterinária , Salmo salar , Alphavirus/classificação , Alphavirus/genética , Infecções por Alphavirus/diagnóstico , Animais , Anticorpos Antivirais/sangue , Noruega , Pancreatopatias/diagnóstico , Pancreatopatias/virologia , Filogenia , Reação em Cadeia da Polimerase , Proteínas Virais/genéticaRESUMO
In 7 instances between 2000 and 2003, clinical investigation of populations of fresh- and seawater-reared, vaccinated, Atlantic salmon Salmo salar suffering total losses of between 0.1 and 35 % revealed infection with a Gram-positive rod-shaped bacterium. The isolations were geographically widespread, occurring in both Norway and Scotland. In all cases, a Gram-positive bacterium, subsequently identified as Rhodococcus erythropolis, was isolated in pure culture. Infections, although systemic, were focused within the peritoneal cavity. While initial attempts to reproduce the disease by intraperitoneal injection of unvaccinated Atlantic salmon failed, Koch's postulates were subsequently fulfilled in fish vaccinated with a commercially available oil-adjuvanted vaccine.
Assuntos
Infecções por Actinomycetales/veterinária , Vacinas Bacterianas/efeitos adversos , Doenças dos Peixes/microbiologia , Rhodococcus/patogenicidade , Salmo salar , Infecções por Actinomycetales/epidemiologia , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/patologia , Animais , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/patologia , Pesqueiros , Genótipo , Cavidade Peritoneal/microbiologia , Fenótipo , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 16S/genética , Rhodococcus/classificação , Rhodococcus/isolamento & purificação , Análise de Sobrevida , Fatores de TempoAssuntos
Surtos de Doenças/veterinária , Doenças dos Peixes/epidemiologia , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/isolamento & purificação , Oncorhynchus mykiss , Animais , DNA Bacteriano/análise , Doenças dos Peixes/patologia , Pesqueiros , Infecções por Flavobacteriaceae/epidemiologia , Infecções por Flavobacteriaceae/patologia , Flavobacterium/genética , Água Doce , Testes de Sensibilidade Microbiana/veterinária , Noruega/epidemiologia , Água do MarAssuntos
Doenças dos Peixes/microbiologia , Francisella/patogenicidade , Gadus morhua/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Animais , Doenças dos Peixes/transmissão , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/transmissão , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: Patients with traumatic brain injury (TBI) often suffer from gastrointestinal dysfunction including intolerance to enteral feedings. However, it is unclear how TBI affects small intestinal contractile activity. The purpose of this study was to determine if TBI affects intestinal smooth muscle function. METHODS: Sprague-Dawley rats were subjected to controlled cortical impact injury (TBI). Sham animals underwent a similar surgery but no injury (SHAM). Animals were sacrificed 1, 3, and 7 days after TBI and intestinal smooth muscle tissue was collected for measurement of contractile activity and transit, NF-kB activity, and cytokine levels. Brains were collected after sacrifice to determine volume loss due to injury. KEY RESULTS: Contractile activity decreased significantly in ileum, but not jejunum, in the TBI group 7 days after injury compared with SHAM. Brain volume loss increased significantly 7 days after injury compared with 3 days and correlated significantly with the contractile activity 1 day after injury. In the intestinal smooth muscle, NF-kB activity increased significantly in the TBI group 3 and 7 days after injury vs SHAM. Wet to dry weight ratio, indicating edema, also increased significantly in the TBI group. Interleukin-1α, -1ß, and -17 increased significantly in the TBI group compared with SHAM. CONCLUSIONS & INFERENCES: Traumatic brain injury causes a delayed but significant decrease in intestinal contractile activity in the ileum leading to delayed transit. The decreased intestinal contractile activity is attributed to secondary inflammatory injury as evidenced by increased NF-kB activity, increased edema, and increased inflammatory cytokines in the intestinal smooth muscle.
Assuntos
Lesões Encefálicas/complicações , Motilidade Gastrointestinal/fisiologia , Contração Muscular/fisiologia , Músculo Liso/fisiopatologia , Animais , Lesões Encefálicas/patologia , Modelos Animais de Doenças , Inflamação/etiologia , Inflamação/metabolismo , Interleucinas/biossíntese , Masculino , NF-kappa B/biossíntese , Ratos , Ratos Sprague-DawleyRESUMO
Amoebic gill disease (AGD) was observed in seawater farmed Atlantic salmon at four geographically distant locations on the western coast of Norway. To the best of our knowledge, these are the first detected AGD outbreaks in Norway. The outbreaks lasted for 7-12 weeks in late autumn 2006 and were for the most part concurrent. The crude, cumulative mortality was in the range of 12-20% at three farms and 82% at a fourth. The histopathology showed uniform parasomal amoebae in lesions characteristic for AGD. Another gill disease, proliferative gill inflammation (PGI), was also present to a variable degree and the distinction between the two gill problems is discussed. Seawater temperatures were 3.5 degrees C higher than average before disease outbreaks, which subsided in early winter. The geographical and time pattern of these outbreaks strongly indicates simultaneous infection from the marine environment. Two contiguous 18S cDNA sequences, obtained by reverse transcriptase PCR from gill tissue with AGD-related lesions, showed highest similarity (99.2%) to a newly recognized species designated Neoparamoeba perurans and maximum likelihood analysis demonstrates that they represent Norwegian strains of this Neoparamoeba lineage.
Assuntos
Doenças dos Peixes/parasitologia , Lobosea/classificação , Filogenia , Infecções Protozoárias em Animais , RNA Ribossômico 18S/genética , Salmo salar/parasitologia , Animais , Primers do DNA/química , DNA Complementar/química , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/mortalidade , Pesqueiros , Brânquias/parasitologia , Brânquias/patologia , Lobosea/genética , Lobosea/patogenicidade , Dados de Sequência Molecular , Noruega/epidemiologia , Oceanos e Mares , Infecções por Protozoários/epidemiologia , Infecções por Protozoários/parasitologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência do Ácido Nucleico , Temperatura , Fatores de TempoRESUMO
Seven bacterial isolates from farmed Atlantic cod displaying chronic granulomatous disease were characterized by phenotypic and molecular taxonomic methods. The isolates were Gram-negative, facultatively intracellular, non-motile, strictly aerobic coccobacilli which produced H(2)S from cysteine-supplemented media and are therefore phenotypically consistent with members of the genus Francisella. Comparison of 16S rRNA gene sequences and six partial housekeeping gene sequences (groEL, shdA, rpoB, rpoA, pgm and atpA) confirmed the organism as a member of the genus Francisella, with Francisella philomiragia as its closest relative (99.3 % 16S rRNA gene sequence similarity, 92.2-99.0 % housekeeping gene sequence similarity). Despite the close relationship with F. philomiragia, isolates from Atlantic cod could be readily distinguished phenotypically and genetically from F. philomiragia ATCC 25015(T). DNA-DNA hybridization studies revealed a mean reassociation value of 68 %. Thus, on the basis of phenotypic and molecular genetic evidence, we propose that the strains isolated from Atlantic cod should be recognized as Francisella philomiragia subsp. noatunensis subsp. nov. with the type strain 2005/50/F292-6C(T) (=NCIMB 14265(T)=LMG 23800(T)). Francisella philomiragia ATCC 25015(T) (=DSM 735(T)) is reclassified as Francisella philomiragia subsp. philomiragia subsp. nov.
Assuntos
Doenças dos Peixes/microbiologia , Francisella/classificação , Francisella/isolamento & purificação , Gadus morhua/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Doença Granulomatosa Crônica/microbiologia , Aerobiose , Animais , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Francisella/genética , Francisella/fisiologia , Genes de RNAr , Infecções por Bactérias Gram-Negativas/microbiologia , Sulfeto de Hidrogênio/metabolismo , Locomoção/fisiologia , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , Quinonas/análise , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
The present paper describes, for the first time, clinical signs and pathological findings of pancreas disease (PD) in farmed Atlantic salmon, Salmo salar L., and rainbow trout, Oncorhynchus mykiss (Walbaum), in sea water in Norway. Similarities and differences with reports of PD from Ireland and Scotland are discussed. Samples of 68 rainbow trout from disease outbreaks on 14 farms and from 155 Atlantic salmon from outbreaks on 20 farms collected from 1996 to 2004 were included in the present study. The histopathological findings of PD in Atlantic salmon and rainbow trout in sea water were similar. Acute PD, characterized by acute necrosis of exocrine pancreatic tissues, was detected in nine Atlantic salmon and three rainbow trout. Salmonid alphavirus (SAV) was identified in acute pancreatic necroses by immunohistochemistry. Most fish showed severe loss of exocrine pancreatic tissue combined with chronic myositis. Myocarditis was often but not consistently found. Kidneys from 40% and 64% of the rainbow trout and Atlantic salmon, respectively, had cells along the sinusoids that were packed with cytoplasmic eosinophilic granules. These cells resembled hypertrophied endothelial cells or elongated mast cell analogues. Histochemical staining properties and electron microscopy of these cells are presented. SAV was identified by RT-PCR and neutralizing antibodies against SAV were detected in blood samples.