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1.
Viral haemorrhagic septicaemia (VHS), caused by the novirhabdovirus viral haemorrhagic septicaemia virus (VHSV), causes significant economic problems to European rainbow trout, Oncorhynchus mykiss (Walbaum), production. The virus isolates can be divided into four distinct genotypes with additional subgroups. The main source of outbreaks in European rainbow trout farming is sublineage Ia isolates. Recently, this group of isolates has been further subdivided in to two subclades of which the Ia‐2 consists of isolates occurring mainly in Continental Europe outside of Denmark. In this study, we sequenced the full‐length G‐gene sequences of 24 VHSV isolates that caused VHS outbreaks in Polish trout farms between 2005 and 2009. All these isolates were identified as genotype Ia‐2; they divided however into two genetically distinct subgroups, that we name Pol I and Pol II. The Pol I isolates mainly caused outbreaks in the southern part of Poland, while Pol II isolates predominantly were sampled in the north of Poland, although it seems that they have been transmitted to other parts of the country. Molecular epidemiology was used for characterization of transmission pathways. This study shows that a main cause of virus transmission appears to be movement of fish. At least in Polish circumstances trading practices appear to have significant impact on spreading of VHSV infection. 相似文献
2.
Abstract. Viral haemorrhagic septicaemia (VHS) is reported for the first time in sea-water cultured rainbow trout. Heavy mortalities with typical signs and lesions A VHS virus (serotype 1) was isolated from the diseased fish. The mortalities were caused only by the VHS virus and 80 days post transfer of trout to sea-water the mortalities reached 85%, of the initial population.
The disease was experimentally transmitted to rainbow trout, both in sea-water 3·104 pfu/ml of virus or by intramuscular injection of various doses of VHS1 (7·101 7·104 or 7·104 pfu per fish). Death occurred in all infected groups and started earlier in sea-water. Typical signs of VHS were observed in moribund fish. Viral multiplication was demonstrated to have occurred in fish organs. 相似文献
The disease was experimentally transmitted to rainbow trout, both in sea-water 3·10
3.
Ana C. A. S. Pinheiro Enrico Volpe Donatella Principi Santino Prosperi Sara Ciulli 《Aquaculture International》2016,24(1):115-125
The major viral diseases that affect rainbow trout (Oncorhynchus mykiss) are viral haemorrhagic septicaemia, infectious haematopoietic necrosis, infectious pancreatic necrosis and sleeping disease. In the presented study, we developed a multiplex RT-PCR (mRT-PCR) assay for the simultaneous detection of these four rainbow trout viruses in a single assay. The choice of primers was carried out based on the expected size of the fragments, the temperature and time required for the amplification, and the specificity for the target sequence. Firstly, the method was optimised using reference strains of viral haemorrhagic septicaemia virus (VHSV), infectious haematopoietic necrosis virus (IHNV), infectious pancreatic necrosis virus (IPNV) and sleeping disease virus (SDV) cultivated with permissive cell culture lines; subsequently, the method was used for the identification of these viral infections in rainbow trout samples. Twenty-two samples of rainbow trout, clinically suspected of having viruses, were analysed by the developed method to detect the presence of the four viruses, by directly analysing the animal tissues. The mRT-PCR method was able to efficiently detect the viral RNA in infected cell culture supernatants and in tissue samples, highlighting the presence of single infections as well as co-infections in rainbow trout samples. VHSV/SDV and IHNV/SDV co-infections were demonstrated for the first time in rainbow trout. The mRT-PCR method was revealed to be an accurate and fast method to support traditional diagnostic techniques in the diagnosis of major viral diseases of rainbow trout. 相似文献
4.
Abstract. The effects of infection with salmonid viruses on mitogen-stimulated cells and colonies from rainbow trout, Oncorhynchus imkiss (Richardson), kidney cell cultures have been studied using culture in clots of fibrin. Phytohaemaglutinin, concanavalin A and lypo-polysaccharides from Escherichia coli have been used as mitogens. The viral haemorrhagic septicaemia (VHS) virus destroyed any mitogen-induced trout kidney colonies or cells, but the infectious pancreatic necrosis (IPN) virus caused no cell or colony death, and even increased their count in the cultures. The results suggested that the target for IPN virus replication is not any trout leucocyte but that among the possible targets of VHS virus are the different types of leucocytes found in the trout kidney and in their in vitro mitogen-stimulated colonies. 相似文献
5.
Viral haemorrhagic septicaemia (VHS) is a well-characterized disease of rainbow trout, Oncorhynchus mykiss, which has also caused economic losses in marine turbot farms in the British Isles. We have previously demonstrated that turbot, Scophthalmus maximus, are susceptible to isolates of viral haemorrhagic septicaemia virus (VHSV) that are endemic in the marine environment, highlighting a potential risk to marine aquaculture. Given the increasing interest in the intensive rearing of additional aquaculture species such as Atlantic cod, Gadus morhua, and Atlantic halibut, Hippoglossus hippoglossus, this study aimed at investigating the susceptibility of these species to VHSV. Both species were found to be largely resistant to VHS following immersion challenge with a selection of 18 isolates, representing the known marine VHSV genotypes. Only one and two VHSV-associated mortalities occurred out of a total of 1710 and 1254 halibut and cod, respectively. These findings suggest that there is a low direct risk to the development of commercial cod and halibut aquaculture from the existing endemic reservoir of VHSV. This study, coupled to field observations has, however, highlighted the fact that both species can become infected with VHSV. The known adaptability of RNA viruses, together with the selection pressures associated with intensive aquaculture would thus advocate a cautious approach to VHSV surveillance within these emerging industries. 相似文献
6.
Stone DM Ferguson HW Tyson PA Savage J Wood G Dodge MJ Woolford G Dixon PF Feist SW Way K 《Journal of fish diseases》2008,31(10):775-784
Viral haemorrhagic septicaemia (VHS) was diagnosed in rainbow trout in the UK in May 2006. VHS virus (VHSV) was isolated from fingerlings showing typical histopathological lesions at a single rainbow trout farm site experiencing high mortality. The virus was confirmed as VHSV by serological and molecular biological tests. Phylogenetic analysis based on the complete glycoprotein gene sequence revealed that the isolate was closely related (99% nucleotide identity) to several Danish isolates from 1991 to 2000 and was assigned to VHSV genogroup Ia. The pathogenicity of the isolate was determined in infection experiments using rainbow trout fry. Following waterborne challenge, cumulative mortalities reached 96.67-100% by 12 days post-infection. This represents the first isolation of a pathogenic freshwater VHSV in the UK. 相似文献
7.
Abstract. Two outbreaks of viral haemorrhagic septicaemia (VHS) have been detected in grayling, Thymallus thymallus L., in Switzerland, The affected fry showed a septicaemic haemorrhage. Due to their similar biotopes, the susceptibility of grayling and rainbow trout to the VHS virus has been compared. The mortality rates varied between 56 and 100% depending on the age of the fish and the infection dose, but no distinct loss-associated difference occurred between grayling and rainbow trout when comparing the same age group and infection dose. Anaemia, scattered subcutaneous and intermuscular haemorrhages and enteritis were frequent macroscopic findings. The major histopathological changes included necrotic foci in the liver, spleen, intestinal mucosa and haematopoietic part of the kidney, whereas a severe tubulonephrosis was detectable in the urinary part of the kidney. 相似文献
8.
Egtved virus: temperature-dependent immune response of trout to infection with low-virulence virus 总被引：1，自引：0，他引：1
P. E. VESTERGÅRD JØRGENSEN 《Journal of fish diseases》1982,5(1):47-55
Abstract. The present report deals with experiments concerning the theoretical basis for development of a live, attenuated vaccine against viral haemorrhagic septicaemia (VHS) of rainbow trout, Salmo gairdneri Richardson, on the basis of a virus strain derived from the Egtved virus reference strain F, the pathogenicity of which has been strongly reduced by in vitro passage. It is shown that the low pathogenicity of the virus (designated the Reva strain) is a genetically stable feature and that the protection against VHS induced by infection with the virus is due to an immune response. Following immunological priming at 10°C partial protection developed at 5° 10° and 15° but not at 20°C, whereas neutralizing antibody was produced at all four temperatures by some of the fish. The duration of virus persistence in trout was found to be inversely proportional to the water temperature. 相似文献
9.
Abstract. Electron microscopical and histopathological investigations were carried out on the anterior kidney often 1-year-old farmed rainbow trout naturally infected with the external signs of viral haemorrhagic septicaemia (VHS). The histopathology of the liver and the haematology of peripheral blood were also examined. The presumptive virus of VHS was directly demonstrated for the first time in the anterior kidney.
All diseased fishes showed necrotic changes in the kidney and the liver. The melano-macrophage centres of the anterior kidney showed a partial destruction accompanied with a loss of melanin. A progressive destruction of the erythrocytes was observed. The liver exhibited moderate to extensive necrosis (karyorrhexis and karyolysis with lymphocytic invasion in the necrotic areas). Neither intranuclear nor intracytoplasmatic inclusions were observed. In the peripheral blood diverse stages of erythrocytic degeneration, amitoses of the erythrocytes and a five-fold increase in lymphocyte numbers were observed. 相似文献
All diseased fishes showed necrotic changes in the kidney and the liver. The melano-macrophage centres of the anterior kidney showed a partial destruction accompanied with a loss of melanin. A progressive destruction of the erythrocytes was observed. The liver exhibited moderate to extensive necrosis (karyorrhexis and karyolysis with lymphocytic invasion in the necrotic areas). Neither intranuclear nor intracytoplasmatic inclusions were observed. In the peripheral blood diverse stages of erythrocytic degeneration, amitoses of the erythrocytes and a five-fold increase in lymphocyte numbers were observed. 相似文献
10.
Schönherz AA Hansen MH Jørgensen HB Berg P Lorenzen N Einer-Jensen K 《Journal of fish diseases》2012,35(6):395-406
Surveys among wild marine fish have revealed occurrence of viral haemorrhagic septicaemia virus (VHSV) infections in a high number of diverse fish species. In marine aquaculture of rainbow trout, preying on invading wild fish might thus be a risk factor for introduction and adaptation of VHSV and subsequent disease outbreaks. Our objective was to determine whether an oral transmission route for VHSV in rainbow trout exists. Juvenile trout were infected through oral, waterborne and cohabitation transmission routes, using a recombinant virus strain harbouring Renilla luciferase as reporter gene. Viral replication in stomach and kidney tissue was detected through bioluminescence activity of luciferase and qRT-PCR. Replication was detected in both tissues, irrespective of transmission route. Replication patterns, however, differed among transmission routes. In trout infected through oral transmission, replication was detected in the stomach prior to kidney tissue. In trout infected through waterborne or cohabitation transmission, replication was detected in kidney prior to stomach or in both tissues simultaneously. We demonstrate the existence of an oral transmission route for VHSV in rainbow trout. This implies that preying on invading infected wild fish is a risk factor for introduction of VHSV into marine cultures of rainbow trout. 相似文献
11.
利用RT-PCR方法扩增出IPNV-ZYX分离株主要结构蛋白VP2的抗原表位区基因(616 bp), 命名为IPNV VP2 COE, 将其克隆到pCold TF表达载体中构建重组质粒pCold TF-VP2 COE, 在大肠杆菌BL21(DH5α)感受态表达, 经SDS-PAGE电泳分析, 表达蛋白约78 ku, 用镍离子亲和层析柱纯化该蛋白, 制备抗血清, 间接ELISA结果显示, IPNV (ATCC VR-1318)细胞培养物与鼠抗VP2 COE蛋白血清发生特异性反应, 效价为1∶12 800; 间接免疫荧光结果显示, 鼠抗VP2 COE血清可与黑龙江某渔场已知感染IPNV虹鳟肝组织产生特异性的荧光, 以上两项结果表明, 表达IPNV VP2 COE蛋白具有良好的免疫原性和免疫反应性, 为IPNV检测方法的建立及疫苗的制备提供理论依据 相似文献
12.
Mark Henryon Peer Berg Niels J. Olesen Torben E. Kj r Wilhelmina J. Slierendrecht Alfred Jokumsen Ivar Lund 《Aquaculture (Amsterdam, Netherlands)》2005,250(3-4):621-636
In this study, we reasoned that if we challenged rainbow trout with the causative agents of enteric redmouth disease (ERM), rainbow trout fry syndrome (RTFS), and viral haemorrhagic septicaemia (VHS), we would: 1) detect additive genetic variation for resistance to ERM, RTFS, and VHS; and 2) find that resistance of the trout to ERM and RTFS are favourably correlated genetically, while resistance to VHS is unfavourably correlated with resistance to ERM and RTFS. We tested these premises by challenging 63 full-sib families of rainbow trout (50 sires, 38 dams) with Yersinia ruckeri, Flavobacterium psychrophilum, and VHS virus, the causative agents of ERM, RTFS, and VHS. Resistance to each disease was assessed as both a binary trait (i.e., died/survived) and a longitudinal trait (i.e., time until death following challenge). Additive genetic variation and genetic correlations for resistance to ERM, RTFS, and VHS were estimated by fitting a threshold liability model to resistance assessed as a binary trait. As a longitudinal trait, additive genetic variation and genetic correlations were estimated by fitting a Weibull frailty model to the times until death. Our findings support the first of our premises as we detected additive genetic variation for resistance to ERM, RTFS, and VHS. The heritability for resistance to ERM, RTFS, and VHS ranged between 0.42 and 0.57 on the underlying liability scale when resistance was assessed as a binary trait. As a longitudinal trait, the heritabilities ranged between 0.07 and 0.21 for time until death on the logarithmic-time scale. We were, however, unable to support our second premise as we found that resistance to each of the diseases tended to be weakly correlated genetically. The genetic correlations between the resistances ranged between −0.11 and 0.15 when resistance was assessed as a binary trait, and between −0.23 and 0.16 when resistance was assessed as a longitudinal trait. These findings are encouraging for commercial trout production. The additive genetic variation detected for resistance demonstrates that selectively breeding trout for resistance to ERM, RTFS, and VHS will be successful, providing a complementary approach to control these diseases. The weak genetic correlations suggest that it should be relatively easy to improve resistance to each of the diseases simultaneously. 相似文献
13.
Jee Youn Hwang Sang Jung Ahn Mun-Gyeong Kwon Jung Soo Seo Seong Don Hwang Bo Young Jee 《Journal of fish diseases》2020,43(5):599-607
Whole-genome next-generation sequencing was used to investigate the local evolution of viral haemorrhagic septicaemia virus, a serious pathogen affecting economically important fish such as rainbow trout and turbot in Europe and olive flounder in Asia. Sequence analysis showed that all isolates were genotype IVa, but could be classified further into four subgroups (K1–K4). In addition, genomic regions encompassing the nucleoprotein, phosphoprotein, matrix protein and non-virion protein genes, as well as the seven non-coding regions, were relatively conserved, whereas glycoprotein and RNA-dependent RNA polymerase genes were variable in the coding region. Taken together, the data demonstrate that whole-genome next-generation sequencing may be useful for future surveillance, prevention and control strategies against viral haemorrhagic septicaemia. 相似文献
14.
Abstract. Kidney function was studied in unanaesthetized rainbow trout, Salmo gairdneri Richardson, with acute infection by VHS virus strain F-l causing viral haemorrhagic septicaemia. The experiments were performed in diseased and control fish with catheters chronically implanted in the dorsal aorta and the urinary bladder. Glomerular clearance of polyfructosan, tubular handling of fluid and electrolytes and urinary excretion of protein were studied. In diseased fish, plasma concentrations of inorganic solutes were reduced, but plasma osmolarity and systemic blood pressure remained unchanged. Glomerular filtration rate and urine flow, both linearly correlated, were reduced from 5.20±0.40 to 3.08±0.66 ml/h/kg and from 2.51±0.15 to 1.63±0.28 ml/h/kg, respectively (±SEM). The urine osmolarity was augmented due to increased Na and Mg concentrations in the urine. Net tubular secretion of Mg was observed in diseased fish whereas net reabsorption of Mg prevailed in the controls. Decreased renal protein excretion rate prevented a renal loss of protein and, therefore, diminished plasma protein concentrations in VHS-infected fish may be attributed to extrarenal pathophysiological mechanisms. 相似文献
15.
16.
O L M Haenen H Schuetze M Cieslak S Oldenburg M A H Spierenburg I Roozenburg‐Hengst M Voorbergen‐Laarman M Y Engelsma N J Olesen 《Journal of fish diseases》2016,39(8):971-979
In spring 2008, infectious hematopoietic necrosis virus (IHNV) was detected for the first time in the Netherlands. The virus was isolated from rainbow trout, Oncorhynchus mykiss (Walbaum), from a put‐and‐take fishery with angling ponds. IHNV is the causative agent of a serious fish disease, infectious hematopoietic necrosis (IHN). From 2008 to 2011, we diagnosed eight IHNV infections in rainbow trout originating from six put‐and‐take fisheries (symptomatic and asymptomatic fish), and four IHNV infections from three rainbow trout farms (of which two were co‐infected by infectious pancreatic necrosis virus, IPNV), at water temperatures between 5 and 15 °C. At least one farm delivered trout to four of these eight IHNV‐positive farms. Mortalities related to IHNV were mostly <40%, but increased to nearly 100% in case of IHNV and IPNV co‐infection. Subsequent phylogenetic analysis revealed that these 12 isolates clustered into two different monophyletic groups within the European IHNV genogroup E. One of these two groups indicates a virus‐introduction event by a German trout import, whereas the second group indicates that IHNV was already (several years) in the Netherlands before its discovery in 2008. 相似文献
17.
Abstract One hundred and forty-eight wild whitefish, Coregonus lavaretus (L.), were caught by electrofishing and sampled for virological examination in December 1999 and 2000, during migration from the brackish water feeding grounds to the freshwater spawning grounds, where the whitefish may come into contact with farmed rainbow trout. All samples were examined on cell cultures. No viruses were isolated. Three viral haemorrhagic septicaemia virus (VHSV) isolates of different origin were tested in infection trials by immersion and intraperitoneal (IP) injection, using 1.5 g farmed whitefish: an isolate from wild caught marine fish, a farmed rainbow trout isolate with a suspected marine origin and a classical freshwater isolate. The isolates were highly pathogenic by IP injection where 99-100% of the whitefish died. Using an immersion challenge the rainbow trout isolates were moderately pathogenic with approximately 20% mortality, whereas the marine isolate was virtually non-pathogenic. At the end of the experiment it was possible to isolate VHSV from survivors infected with the marine and suspected marine isolates. Because of the low infection rate in wild whitefish in Denmark, the role of whitefish in the spread of VHSV in Denmark is probably not significant. The experimental studies, however, showed that whitefish are potential carriers of VHSV as they suffer only low mortality after infection but continue to carry virus. 相似文献
18.
Viral haemorrhagic septicaemia (VHS) is a serious disease in several fish species. VHS is caused by the rhabdovirus viral haemorrhagic septicaemia virus (VHSV). To prevent spreading of the pathogen, it is important to use a fast, robust, sensitive and specific diagnostic tool to identify the infected fish. Traditional diagnosis based on isolation in cell culture followed by identification using, for example, ELISA is sensitive and specific but slow. By switching to RT‐PCR for surveillance and diagnosis of VHS the time needed before a correct diagnosis can be given will be considerably shortened and the need for maintaining expensive cell culture facilities reduced. Here we present the validation, according to OIE guidelines, of a sensitive and specific Taqman‐based real‐time RT‐PCR. The assay detects all isolates in a panel of 79 VHSV isolates covering all known genotypes and subtypes, with amplification efficiencies of approximately 100%. The analytical and diagnostic specificity of the real‐time RT‐PCR is close to 1, and the analytical and diagnostic sensitivity is comparable with traditional cell‐based methods. In conclusion, the presented real‐time RT‐PCR assay has the necessary qualities to be used as a VHSV surveillance tool on par with cell culture assays. 相似文献
19.
Isaac R. Mulei Phillip N. Nyaga Paul G. Mbuthia Robert M. Waruiru Cheng Xu
ystein Evensen Stephen Mutoloki 《Journal of fish diseases》2019,42(5):751-758
Infectious haematopoietic necrosis virus (IHNV) is the causative agent of infectious haematopoietic necrosis, a disease of salmonid responsible for great economic losses. The disease occurs in most parts of the world where rainbow trout is reared but has not been previously reported in Kenya. In this study, rainbow trout fry and growers from two farms in Nyeri County were screened for IHNV. Whole fry (n = 4 from each farm) and kidney samples from growers (n = 15 and n = 6 from the two farms, respectively) were collected and preserved for cell culture examination or PCR analysis. Screening of samples was done by PCR followed by sequencing of the glycoprotein gene of the virus. Demonstration of the virus was done by propagation in EPC cells followed by the indirect fluorescence antibody test (IFAT). The results revealed the presence of IHNV at low prevalence of 0.1 and 0.4 for the two farms. The virus was confirmed both by IFAT and by partial sequencing of the G gene. Phylogenetic analysis revealed that the Kenyan isolates were identical to those of the J genogroup found mostly in Asia. The findings have implications for biosecurity measures and import regulations for the Kenyan rainbow trout industry. 相似文献
20.
VHSV IVb infection and autophagy modulation in the rainbow trout gill epithelial cell line RTgill-W1
Juan-Ting Liu Phuc H. Pham Sarah K. Wootton Niels C. Bols John S. Lumsden 《Journal of fish diseases》2020,43(10):1237-1247
Autophagy modulation influences the success of intracellular pathogens, and an understanding of the mechanisms involved might offer practical options to reduce the impact of infectious disease. Viral haemorrhagic septicaemia virus (VHSV) can cause high mortality and economic loss in some commercial fish species. VHSV IVb was used to infect a rainbow trout gill cell line, RTgill-W1, followed by the treatment of the cells with different autophagy-modulating reagents. LC3II protein using Western blot was significantly (p < .05) decreased for two days following VHSV infection, and immunofluorescence confirmed that LC3II-positive intracytoplasmic puncta were also decreased. Infection with VHSV resulted in significantly decreased expression of the autophagy-related (Atg) genes atg4, at12, atg13 and becn1 after one day using quantitative PCR. Both viral gene copy number and VHSV N protein were significantly decreased by treating the cells with autophagy-blocking (chloroquine) and autophagy-inhibiting reagents (deoxynivalenol and 3-methyladenine) after three days, while autophagy induction (restricted nutrition and rapamycin) had limited effect. Only treatment of RTgill-W1 with deoxynivalenol resulted in a significant increase in expression of type I interferon. Therefore, the suppression of autophagy initially occurs after VHSV IVb infection, but the modulation of autophagy can also inhibit VHSV IVb infection in RTgill-W1 after three days. 相似文献