期刊
【作者单位】
="Finnish Food Safety Authority Evira Department of Animal Diseases and Finnish Food Safety Authority Evira Department of Animal Diseases and Food Safety Research Virology Unit Mustialankatu 3 00790 Helsinki Finland [mailto:hannele.tapiovaara@evira.f"
摘要 :
In Finland, viral haemorrhagic septicaemia virus (VHSV) was diagnosed for the first time in 2000 from 4 rainbow trout farms in brackish water. Since then the infection has spread and, by the end of 2004, VHSV had been isolated fro...
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In Finland, viral haemorrhagic septicaemia virus (VHSV) was diagnosed for the first time in 2000 from 4 rainbow trout farms in brackish water. Since then the infection has spread and, by the end of 2004, VHSV had been isolated from 24 farms in 3 separate locations: 2 in the Baltic Sea and 1 in the Gulf of Finland. The pathogenicity of 3 of these isolates from 2 separate locations was analysed in infection experiments with rainbow trout fry. The cumulative mortalities induced by waterborne and intraperitoneal challenge were approximately 40 and 90%, respectively. Pair-wise comparisons of the G and NV gene regions of Finnish VHSV isolates collected between 2000 and 2004 revealed that all isolates were closely related, with 99.3 to 100% nucleotide identity, which suggests the same origin of infection. Phylogenetic analysis revealed that they were closely related to the old freshwater isolates from rainbow trout in Denmark and to one old marine isolate from cod in the Baltic Sea, and that they were located close to the presumed ancestral source. As the Finnish isolates induce lower mortality than freshwater VHSV isolates in infection experiments, they could represent an intermediate stage of marine isolates evolving towards pathogenicity in rainbow trout.
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摘要 :
In Finland, viral haemorrhagic septicaemia virus (VHSV) was diagnosed for the first time in 2000 from 4 rainbow trout farms in brackish water. Since then the infection has spread and, by the end of 2004, VHSV had been isolated fro...
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In Finland, viral haemorrhagic septicaemia virus (VHSV) was diagnosed for the first time in 2000 from 4 rainbow trout farms in brackish water. Since then the infection has spread and, by the end of 2004, VHSV had been isolated from 24 farms in 3 separate locations: 2 in the Baltic Sea and 1 in the Gulf of Finland. The pathogenicity of 3 of these isolates from 2 separate locations was analysed in infection experiments with rainbow trout fry. The cumulative mortalities induced by waterborne and intraperitoneal challenge were approximately 40 and 90%, respectively. Pair-wise comparisons of the G and NV gene regions of Finnish VHSV isolates collected between 2000 and 2004 revealed that all isolates were closely related, with 99.3 to 100% nucleotide identity, which suggests the same origin of infection. Phylogenetic analysis revealed that they were closely related to the old freshwater isolates from rainbow trout in Denmark and to one old marine isolate from cod in the Baltic Sea, and that they were located close to the presumed ancestral source. As the Finnish isolates induce lower mortality than freshwater VHSV isolates in infection experiments, they could represent an intermediate stage of marine isolates evolving towards pathogenicity in rainbow trout.
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摘要 :
In June 2003, a horse imported to Finland from Estonia showed neurological signs suggestive of rabies. The rabies diagnosis was confirmed with a direct fluorescent antibody test, by isolating the virus in cell culture, by reverse ...
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In June 2003, a horse imported to Finland from Estonia showed neurological signs suggestive of rabies. The rabies diagnosis was confirmed with a direct fluorescent antibody test, by isolating the virus in cell culture, by reverse transcription polymerase chain reaction (RT-PCR), and partial sequencing of the viral genome. The close relationship of the equine virus strain to the current Estonian strains was verified in subsequent molecular epidemiologic studies. Because the case was clearly imported, it did not affect Finland's rabies-free status..
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Official vaccine sales statistics, the development of the young dog population and the takes of available vaccines were used to calculate the vaccine coverage and herd immunity (HI) against canine distemper, endemic during 1990-19...
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Official vaccine sales statistics, the development of the young dog population and the takes of available vaccines were used to calculate the vaccine coverage and herd immunity (HI) against canine distemper, endemic during 1990-1993 and epidemic in 1994-1995 in Finland. Despite the satisfactory vaccine coverage, HI was no more than 50-65% in 1990-1993 because low-take vaccines dominated the market. Replacement of the low-take with high-take vaccines in 1995 raised the HI to 90%, which coincided with the ending of the epidemic. In 1996, the HI was slightly above 70%, which was sufficient to control the disease despite infectious pressure caused by repeated imports.
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The capabilities of seven Finnish Fusarium species to produce mycotoxins under controlled laboratory (in vitro) conditions as well as on barley and wheat in the field (in vivo) were studied using mass spectrometric methods. In add...
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The capabilities of seven Finnish Fusarium species to produce mycotoxins under controlled laboratory (in vitro) conditions as well as on barley and wheat in the field (in vivo) were studied using mass spectrometric methods. In addition, the contaminating Fusarium species of the in vivo samples were identified and quantified with morphological and real-time polymerase chain reaction techniques. All investigated isolates (representing the species F. avenaceum, F. arthrosporioides, F. tricinctum, F. poae, F. culmorum, F. graminearum and F. sporotrichioides) produced mycotoxins on rice cultures and their production capabilities were generally in accordance with the available literature. The main mycotoxins produced were deoxynivalenol, 3-acetyldeoxynivalenol and zearalenone by F. culmorum and F. graminearum, beauvericin, diacetoxyscirpenol and HT-2/T-2 - toxins by F. sporotrichioides, beauvericin, enniatins, fusarenon-X, diacetoxyscirpenol and nivalenol by F. poae and enniatins and moniliformin by F. avenaceum/F. arthrosporioides and F. tricinctum. Most mycotoxins that were produced in vitro were also produced in vivo when concerning F. culmorum, F. graminearum and F. avenaceum. Statistical significance was recorded between the production of mycotoxins in vitro and in vivo for HT-2 and T-2 toxins in barley and for deoxynivalenol and T-2 toxin in wheat.
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摘要 :
The contamination of foods and feed with mycotoxins is a commonly known problem. Intense investigations have been conducted to study the occurrence, toxicity, and recently also the prevention and detoxification strategies of mycot...
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The contamination of foods and feed with mycotoxins is a commonly known problem. Intense investigations have been conducted to study the occurrence, toxicity, and recently also the prevention and detoxification strategies of mycotoxins in human and animal food chains. Most of the studies have emphasized on "traditional" mycotoxins, such as aflatoxins, ochratoxin A, and trichothecenes. However, one of the most common grain-contaminating genus of fungi, Fusarium spp., is also capable of producing other toxic secondary metabolites - the so-called emerging mycotoxins such as fusaproliferin, beauvericin, enniatins, and moniliformin. So far, only limited data is available on these metabolites. This is not only due to their late recognition but especially the late understanding of their role as mycotoxins. This paper summarizes the existing data on the chemistry, analytical techniques, biosynthesis, production, toxicity, and occurrence data on fusaproliferin, beauvericin, enniatins, and moniliformin. Based on the available studies, attention should be paid to the studies on the distinct signifigance of these compounds in the human and animal food chains.
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The RV-97 rabies virus vaccine strain is widely used in Russia as a component of the live attenuated oral anti-rabies vaccine "Sinrab". This vaccine has also been used in some other countries, such as Kazakhstan, Belarus, and Ukra...
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The RV-97 rabies virus vaccine strain is widely used in Russia as a component of the live attenuated oral anti-rabies vaccine "Sinrab". This vaccine has also been used in some other countries, such as Kazakhstan, Belarus, and Ukraine. Entire genome sequencing is an effective tool for studying the genetic properties of virus strains. In this study, a simple technique for obtaining the entire genome sequence of the rabies virus was used. The entire genome sequence and the deduced amino acid sequences of the major viral proteins were compared with those of other rabies vaccine virus strains. The RV-97 strain forms a separate phylogenetic branch and seems to be phylogenetically more related to the group of Japanese vaccine strains. It also contains several unique amino acid changes in known immunodominant sites of G and P proteins.
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A quantitative real-time PCR (qPCR) based on a standard curve was developed for detection and quantitation of ranaviruses. The target gene for the qPCR was viral DNA polymerase (DNApol). All ten ranavirus isolates studied (Epizoot...
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A quantitative real-time PCR (qPCR) based on a standard curve was developed for detection and quantitation of ranaviruses. The target gene for the qPCR was viral DNA polymerase (DNApol). All ten ranavirus isolates studied (Epizootic haematopoietic necrosis virus, EHNV; European catfish virus, ECV; European sheatfish virus, ESV; Frog virus 3, FV3; Bohle iridovirus, BIV; Doctor fish virus, DFV; Guppy virus 6, GV6; Pike-perch iridovirus, PPIV; Rana esculenta virus Italy 282/I02, REV282/I02 and Short-finned eel ranavirus, SERV) were detected with the qPCR assay. In addition, two fish cell lines - epithelioma papulosum cyprini (EPC) and bluegill fry (BF-2) - were infected with four of the isolates (EHNV, ECV, FV3 and DFV), and the viral quantity was determined from seven time points during the first three days after infection. The qPCR was also used to determine the viral load in tissue samples from pike (Esox lucius) fry challenged experimentally with EHNV.
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Ranaviruses (family Iridoviridae) are a growing threat to fish and amphibian populations worldwide. The immune response to ranavirus infection has been studied in amphibians, but little is known about the responses elicited in pis...
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Ranaviruses (family Iridoviridae) are a growing threat to fish and amphibian populations worldwide. The immune response to ranavirus infection has been studied in amphibians, but little is known about the responses elicited in piscine hosts. In this study, the immune response and apoptosis induced by ranaviruses were investigated in fish epithelial cells. Epithelioma papulosum cyprini (EPC) cells were infected with four different viral isolates: epizootic haematopoietic necrosis virus (EHNV), frog virus 3 (FV3), European catfish virus (ECV) and doctor fish virus (DFV). Quantitative real-time PCR (qPCR) assays were developed to measure the mRNA expression of immune response genes during ranavirus infection. The target genes included tumour necrosis factor alpha (TNF- alpha ), interleukin-1 beta (IL-1 beta ), beta 2-microglobulin ( beta 2M), interleukin-10 (IL-10) and transforming growth factor beta (TGF- beta ). All ranaviruses elicited changes in immune gene expression. EHNV and FV3 caused a strong pro-inflammatory response with an increase in the expression of both IL-1 beta and TNF- alpha , whereas ECV and DFV evoked transient up-regulation of regulatory cytokine TGF- beta . Additionally, all viral isolates induced increased beta 2M expression as well as apoptosis in the EPC cells. Our results indicate that epithelial cells can serve as an in vitro model for studying the mechanisms of immune response in the piscine host in the first stages of ranavirus infection.
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The aim of this study was to examine the occurrence of bacterial, mycoplasmal and viral pathogens in the lower respiratory tract of calves in all-in all-out calf-rearing units. According to clinical status, non-medicated calves wi...
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The aim of this study was to examine the occurrence of bacterial, mycoplasmal and viral pathogens in the lower respiratory tract of calves in all-in all-out calf-rearing units. According to clinical status, non-medicated calves with and without respiratory disease signs were selected of the 40 herds investigated to analyse the micro-organisms present in healthy and diseased calves. Tracheobronchial lavage (TBL) and paired serum samples were analysed for bacteria, mycoplasmas, respiratory syncytial virus (RSV), parainfluenza virus 3 (PIV3), bovine corona virus (BCV) and bovine adenovirus (BAV). Pasteurella multocida was the most common bacterial pathogen. It was isolated from 34% of the TBL samples in 28 herds and was associated with clinical respiratory disease (p < 0.05) when other pathogenic bacteria or mycoplasma were present in the sample. Mannheimia spp. and Histophilus somni were rarely found. Mycoplasma bovis was not detected at all. Ureaplasma diversum was associated with clinical respiratory disease (p < 0.05). TBL samples from healthy or suspect calves were more often negative in bacterial culture than samples from diseased calves (p < 0.05). No viral infections were detected in six herds, while 16-21 herds had RSV, BCV, BAV or PIV3. In the herds that had calves seroconverted to BCV, respiratory shedding of BCV was more frequently observed than faecal shedding. This study showed that the microbial combinations behind BRD were diverse between herds. M. bovis, an emerging pathogen in many countries, was not detected.
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