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T Sandvik

Publications and source records attributed to T Sandvik.

At least 19 recordsLinked to original sources
PubMed2006

Genetic and antigenic typing of border disease virus isolates in sheep from the Iberian Peninsula.

A selection of 10 pestiviruses isolated from sheep from the Iberian Peninsula from 2001 to 2004 was characterised at the molecular level. The 5' untranslated region (5'-UTR) and N(pro)-coding gene were amplified by the reverse transcription-polymerase chain reaction (RT-PCR) and sequenced directly from purified products. All isolates were also typed antigenically with a panel of monoclonal antibodies (mAbs) raised against representative isolates of the four recognised pestivirus species. The genetic typing placed all the isolates in a new tentative type 4 of border disease virus (BDV), which was closely related to a pestivirus recently found in Pyrenean chamois (Rupicapra pyrenaica pyrenaica). Overall, the genotyping indicated a relatively wide diversity of the BDV type 4, which was best defined on the basis of N(pro) sequences. Antigenically, the isolates were recognised by two pan-pestivirus specific anti-NS3 mAbs, but only by some of the anti-glycoprotein specific mAbs raised against BDV, indicating partial antigenic overlap with other BDV isolates.

5' Untranslated Regions↗
PubMed2004

Characterisation of a type 2 bovine viral diarrhoea virus isolated from cattle in the UK.

Two genotypes of bovine viral diarrhoea virus (BVDV) are recognised. Type 2 was first recognised when virulent strains caused significant losses among cattle in North America. Subsequently, BVDV type 2 has been found in many other countries, but recent studies have shown that only type 1 BVDV is circulating in the UK herds (sheep and cattle) with type 1a predominating. During routine genotyping of UK BVDV isolates, a type 2 isolate was identified. Phylogenetic analysis of the 5'-untranslated region of the viral genome showed it to be a BVDV type 2a, most similar to a low virulent US strain of BVDV type 2. Antigenic typing with a panel of monoclonal antibodies verified this classification. This is the first confirmed isolation of BVDV type 2 found circulating in the UK.

5' Untranslated Regions↗
PubMed2004

Detection and genetic typing of type 2 porcine circoviruses in archived pig tissues from the UK.

Porcine circovirus 2 (PCV-2) is implicated as the causative agent of post-weaning multisystemic wasting syndrome (PMWS) and is also associated with porcine dermatitis and nephropathy syndrome (PDNS). The recent emergence of epidemic PMWS in the United Kingdom was predated by sporadic cases of PDNS dating back to the early 1980's. The aim of this study was to investigate whether PCV-2 DNA was present in archival tissues, and if so, to investigate the relatedness of these viruses with contemporary strains of PCV-2. DNA extracted from paraffin wax-embedded tissue blocks ( n = 68), was subjected to a TaqMan polymerase chain reaction (PCR) targeting a fragment of ORF1 of PCV-2. Positive results were obtained from 41% (9/22), 31% (4/13) and 32% (8/25) of submissions from the 1990's, 1980's and 1970's respectively. The presence of PCV-2 antigen in some of these tissues was confirmed by immunohistochemistry (IHC). A PCR targeting ORF2 was used to obtain sequence data for phylogenetic analysis. Sequences from 5 archival tissues were unique but showed high genetic identity to PCV-2 sequence obtained from a 2000 PDNS case. These data demonstrate that similar isolates of PCV-2 have been present in the UK pig population for more than 30 years.

Animals↗
PubMed2000

The viral RNA 3'- and 5'-end structure and mRNA transcription of infectious salmon anaemia virus resemble those of influenza viruses.

The nucleotide sequences of the termini of two of the genomic segments of the negative strand RNA virus infectious salmon anaemia virus (ISAV) were determined. The sequence of the terminal 9 nucleotides at both ends of the viral RNAs was identical, and showed distinctive sequence homology with the conserved terminal sequences found in the orthomyxoviruses. For both ISAV genomic segments a computer-based secondary structure modelling indicated that the terminal 21-24 nucleotides were able to form self-complementary panhandle structures. Comparison with ISAV-derived mRNA sequences showed that ISAV mRNAs have heterogeneous 5'-ends, and are polyadenylated from a signal sequence 13-14 nucleotides downstream of the 5'-end terminus of the vRNA. Furthermore, the in vitro replication of ISAV was hindered by the RNA polymerase II inhibitor alpha-amanitin. These findings indicate that the mechanisms for replication of ISAV are similar to those of the orthomyxoviruses, and add to the previously reported structural similarities between ISAV and the orthomyxoviruses.

3' Untranslated Regions↗
PubMed1999

Level and duration of serum antibodies in cattle infected experimentally and naturally with bovine virus diarrhoea virus.

Neutralising serum antibodies against bovine virus diarrhoea virus (BVDV) were monitored for three years in 35 cattle that were infected with the virus as calves; 24 of the calves were inoculated intramuscularly or intranasally, and 11 contracted the infection naturally. All the experimentally infected calves seroconverted within 14 to 28 days after inoculation, and all the animals still had high serum levels of antibodies to BVDV three years after infection. Determinations of antibody levels in milk and blood samples excluded the possibility that the calves had been reinfected with BVDV during the study.

Animals↗
PubMed1999

Laboratory diagnostic investigations for bovine viral diarrhoea virus infections in cattle.

There are no pathognomonic clinical signs of infection with bovine viral diarrhoea virus (BVDV) in cattle. Diagnostic investigations therefore rely on laboratory-based detection of the virus, or of virus-induced antigens or antibodies in submitted samples. In unvaccinated dairy herds, serological testing of bulk milk is a convenient method for BVDV prevalence screening. Alternatively, serological testing of young stock may indicate if BVDV is present in a herd. In BVDV positive herds, animals persistently infected (PI) with BVDV can be identified by combined use of serological and virological tests for examination of blood samples. ELISAs have been used for rapid detection of both BVDV antibodies and antigens in blood, but should preferably be backed up by other methods such as virus neutralization, virus isolation in cell cultures or amplification of viral nucleic acid. Detailed knowledge of the performance of the diagnostic tests in use, as well as of the epidemiology of bovine virus diarrhoea is essential for identification of viremic animals in affected herds.

Animals↗
PubMed1999

Comparison of thymidine kinase and A-type inclusion protein gene sequences from Norwegian and Swedish cowpox virus isolates.

During the last decades, cowpox virus, a member of the genus Orthopoxvirus within the Poxviridae family, has appeared as a pathogen in domestic cats, zoo animal species, and humans. At the same time, vaccinia virus, another orthopoxvirus, has been used as a recombinant vaccine vector with foreign genes inserted in the thymidine kinase (TK) gene. By PCR and cycle sequencing, we have determined the nucleotide sequences of the TK gene and the A-type inclusion protein (ATIP) gene of virus isolates from two human cowpox cases in Sweden, as well as a human and a feline case from Norway. We also obtained the corresponding sequences from ectromelia virus (strain Moscow), cowpox virus (strain Brighton) and vaccinia virus (strain Western Reserve). The new virus isolates differed from ectromelia virus and vaccinia virus, and were confirmed to be cowpox virus strains. Isolates originating from the same country had nearly identical TK sequences and fully identical ATIP sequences. They probably represent local geographical strains of cowpox virus.

Animals↗
PubMed1999

Detection of viral antigen in placenta and fetus of cattle acutely infected with bovine viral diarrhea virus.

The reproductive organs and fetuses of seven Norwegian Red heifers were investigated for the presence of bovine viral diarrhea virus (BVDV) antigen during the time of initial transplacental transmission of the virus. The heifers were inoculated with a noncytopathogenic BVDV at day 85/86 of gestation and were slaughtered at day 7, 10, 14, 18, or 22 postinoculation (pi). Cryostat sections of uterus, ovaries, placentomes, intercotyledonary fetal membranes, and fetal organs were examined using immunohistochemical techniques. A double immunofluorescence technique was used to identify cells that showed staining with antibodies against the leukocyte common antigen CD45 or the intermediate filament vimentin and BVDV antigens. The earliest stage of infection at which BVDV antigen could be detected in the fetuses was 14 days pi. At this stage, BVDV antigen was detected in cells of mesenchymal origin in the lungs and in large cells that morphologically resembled immature megakaryocytes in the liver. In the intercotyledonary fetal membranes and in the placentomes, BVDV antigen was not detected until 18 and 22 days pi, respectively. BVDV antigen was not detected in maternal tissue from any of the heifers. The present results indicate that fetal infection with BVDV can take place without preceding or simultaneous high concentrations of BVDV in uterus or placenta of acutely infected heifers.

Animals↗
PubMed1998

Antibodies to orthopoxvirus in domestic cats in Norway.

The prevalence of antibodies to orthopoxvirus in 217 sera collected from domestic cats in the western part of Norway was 10.1 per cent as measured by a competitive ELISA. In one of the seropositive cats antibodies were also detected by an immunofluorescence assay. The average age of the cats sampled was 4.9 years, but the average age of the seropositive individuals was 7.3 years, higher than the average age of clinical cowpox virus cases in Britain (4.2 years), and in Germany (3.9 years). Antibodies against feline immunodeficiency virus (FIV) were detected in nine of 30 (30 per cent) of the seropositive cats, and in five of 30 (17 per cent) of the seronegative cats, which suggests that FIV infection may influence the susceptibility of domestic cats to orthopoxvirus, or vice versa. Orthopoxvirus infections, have recently been detected in rodent populations in several areas of Norway, and the infection may therefore be present in cats all over the country; cat owners and animal handlers should be aware of this (re)emerging zoonosis.

Animals↗
PubMed1998

Characteristics of four cowpox virus isolates from Norway and Sweden.

We report the first isolation of cowpox virus from a domestic cat in Norway, and the first confirmed isolation of cowpox virus from a human case in Norway. These two Norwegian cowpox virus isolates, as well as two Swedish human isolates, were partially characterized and compared with each other and with cowpox virus Brighton and vaccinia virus strain Western Reserve. Restriction enzyme analysis of the genomes revealed differences between all six viruses examined, but suggested that the two Norwegian isolates are closely related, as are the two Swedish isolates. Restriction endonuclease digestion of genomic DNA demonstrated that one of the Swedish isolates and the two Norwegian isolates have larger genomes than vaccinia virus strain Western Reserve, but smaller than cowpox Brighton. All four Scandinavian isolates lacked a 72 base-pair region within the A-type inclusion body protein gene which is present in the prototype cowpox virus Brighton.

Adolescent↗
PubMed1998

Naturally occurring orthopoxviruses: potential for recombination with vaccine vectors.

Orthopoxviruses are being increasingly used as live recombinant vectors for vaccination against numerous infectious diseases in humans, domestic animals, and wildlife. For risk assessments and surveillance, information about the occurrence, distribution and ecology of orthopoxviruses in western Europe is important but has mainly been based on serological investigations. We have examined kidneys, lungs, spleens, and livers of Norwegian small rodents and common shrews (Sorex araneus) for the presence of orthopoxvirus DNA sequences by PCR with primers complementary to the viral thymidine kinase (TK) gene. PCR amplicons were verified as orthopoxvirus specific by hybridization with a vaccinia virus TK-specific probe. A total of 347 animals (1,388 organs) from eight locations in different parts of Norway, collected at different times of the year during 1993 to 1995, were examined. Fifty-two animals (15%) from five locations, up to 1,600 km apart, carried orthopoxvirus DNA in one or more of their organs, most frequently in the lungs. These included 9 of 68 (13%) bank voles (Clethrionomys glareolus), 4 of 13 (31%) gray-sided voles (Clethrionomys rufocanus), 3 of 11 (27%) northern red-backed voles (Clethrionomys rutilus), 16 of 76 (21%) wood mice (Apodemus sylvaticus), and 20 of 157 (13%) common shrews. The previous isolation of cowpox virus from two clinical cases of infection (human and feline) at two of the locations investigated suggests that the viruses detected are cowpox and that some of the virus-carrying small mammalian species should be included among the cowpox virus natural reservoir hosts in Scandinavia and western Europe.

Animals↗
PubMed1998

Serosurvey for orthopoxviruses in rodents and shrews from Norway.

Two hundred and twenty one blood samples representing eight different rodent species and the common shrew (Sorex araneus), collected in Norway between 1993 and 1995, were examined for anti-orthopoxvirus antibodies by a competition enzyme linked imunnosorbent assay (ELISA) and, when possible, an indirect immunofluorescence assay. The serological results indicated that the bank vole (Clethrionomys glareolus), woodmouse (Apodemus sylvaticus) and Norway lemming (Lemmus lemmus) may be reservoir species for orthopoxviruses in Norway, with antibody prevalences of 17 (12/69), 30 (24/81) and 56% (19/34), respectively. Orthopoxvirus infection in lemmings has not been reported previously. On some other small rodent species such as field voles (Microtus agrestis), common rats (Rattus norvegicus), and common shrews, seropositive individuals were detected. However, the total number of tested animals was low, and the role of these species in the epidemiology of orthopoxvirus infections remains unclear. Attempts to isolate orthopoxviruses from these small mammals failed, although orthopoxvirus specific DNA sequences were detected previously in the same animals by the polymerase chain reaction (PCR). The serological results were compared with and discussed in the context of the occurrence of orthopoxvirus-specific DNA sequences, and it is concluded that orthopoxviruses are widely distributed among wildlife in Norway.

Animals↗
PubMed1998

Antibodies against orthopoxviruses in wild carnivores from Fennoscandia.

Two hundred and three sera obtained in 1993-96 from red foxes (Vulpes vulpes), lynx (Lynx lynx), brown bears (Ursus arctos) and wolverines (Gulo gulo) in Fennoscandia (Norway, Sweden, and Finland) were examined for the presence of anti-orthopoxvirus antibodies by a competition enzyme linked immunosorbent assay (ELISA). High prevalences were found for the red foxes in Norway (7/62, 11%) and Finland (7/14, 50%). While only one of 73 (1%) lynx from Finland had anti-orthopoxvirus antibodies, a high prevalence was found in sera from the Sarek National Park in Sweden (5/17, 29%). In addition, anti-orthopoxvirus antibodies were found in one brown bear from the same area (1/45, 2%), whereas none of the 14 wolverines were seropositive. This is the first report of anti-orthopoxvirus antibodies in the brown bear and the lynx, and the first screening for such antibodies in Sweden and Finland. These results indicate that orthopoxviruses are distributed in Sweden and Finland as well as in Norway, and that the red fox and the European lynx may serve as indicator species for the presence of orthopoxviruses in the local populations of small mammals.

Animals↗