| 1. |
- Abro, Shahid, hussain, et al.
(författare)
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Emergence of novel strains of avian infectious bronchitis virus in Sweden
- 2012
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 155, s. 237-246
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Tidskriftsartikel (refereegranskat)abstract
- Infectious bronchitis virus (IBV) causes avian infectious bronchitis, an important disease that produces severe economic losses in the poultry industry worldwide. Recent IBV infections in Sweden have been associated with poor growth in broilers, drop in egg production and thin egg shells in layers. The complete spike gene of selected isolates from IBV cases was amplified and sequenced using conventional RT-PCR. Nucleotide and amino acid sequence comparisons have shown that the recent isolates bear 98.97% genetic similarity with strains of the QX-like genotype. The phylogenetic analysis revealed that strains predominant in the nineties, which were of the Massachusetts type, have been replaced by D388/QX-Iike strains, however the evolutionary link could not be established. The homology between the two genotypes was 79 and 81%. Remarkably, a strong positive selection pressure was determined, mostly involving the S1 subunit of the S gene. This strong selective pressure resulted in recombination events, insertions and deletions in the S gene. Two new isolates generated from recombination were found with nucleotide sequence diverging 1.7-2.4% from the D388/QX-Iike branch, indicating the emergence of a new lineage. The study demonstrates a constant evolution of IBV that might be in relation to increased poultry farming, trade and vaccine pressure. The findings underscore the importance of continuous monitoring to control spread of infections, as well as to timely adjust diagnostic methods, molecular epidemiological studies, development and use of vaccines that are adapted to the changing disease scenario. (C) 2011 Elsevier B.V. All rights reserved.
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| 2. |
- Alvarez, Ignacio, et al.
(författare)
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Proteomic and Lipidomic Profiling of Calves Experimentally Co-Infected with Influenza D Virus and Mycoplasma bovis : Insights into the Host-Pathogen Interactions
- 2024
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Ingår i: Viruses. - : MDPI. - 1999-4915. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- The role of Influenza D virus (IDV) in bovine respiratory disease remains unclear. An in vivo experiment resulted in increased clinical signs, lesions, and pathogen replication in calves co-infected with IDV and Mycoplasma bovis (M. bovis), compared to single-infected calves. The present study aimed to elucidate the host-pathogen interactions and profile the kinetics of lipid mediators in the airways of these calves. Bronchoalveolar lavage (BAL) samples collected at 2 days post-infection (dpi) were used for proteomic analyses by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Additionally, lipidomic analyses were performed by LC-MS/MS on BAL samples collected at 2, 7 and 14 dpi. Whereas M. bovis induced the expression of proteins involved in fibrin formation, IDV co-infection counteracted this coagulation mechanism and downregulated other acute-phase response proteins, such as complement component 4 (C4) and plasminogen (PLG). The reduced inflammatory response against M. bovis likely resulted in increased M. bovis replication and delayed M. bovis clearance, which led to a significantly increased abundance of oxylipids in co-infected calves. The identified induced oxylipids mainly derived from arachidonic acid; were likely oxidized by COX-1, COX-2, and LOX-5; and peaked at 7 dpi. This paper presents the first characterization of BAL proteome and lipid mediator kinetics in response to IDV and M. bovis infection in cattle and raises hypotheses regarding how IDV acts as a co-pathogen in bovine respiratory disease.
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| 3. |
- Berg, Mikael, et al.
(författare)
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Sequencing and analysis of the complete genome of Newcastle disease virus isolated from a commercial poultry farm in 2010
- 2012
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Ingår i: Archives of Virology. - : Springer Science and Business Media LLC. - 0304-8608 .- 1432-8798. ; 157, s. 765-768
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Tidskriftsartikel (refereegranskat)abstract
- Newcastle disease virus (NDV) infects wild and domestic birds but causes contagious and lethal disease in domestic poultry. ND is currently endemic in Pakistan, but no complete genome sequence of a Pakistani NDV isolate has been reported. An NDV strain isolated from a commercial poultry farm was completely sequenced. Phylogenetic analysis revealed that the isolate is closely related to genotype VII and, more specifically, to subgenotype VIIb, yet with substantial enough differences to be regarded as new subgenotype (VIIf). These findings provide insight into the genetic nature of NDV circulating in Pakistan and are useful for both laboratory diagnosis and vaccine development for NDV.
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| 4. |
- Gyarmati, Péter, et al.
(författare)
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Simultaneous genotyping of all hemagglutinin and neuraminidase subtypes of avian influenza viruses by use of padlock probes
- 2008
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 46:5, s. 1747-1751
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Tidskriftsartikel (refereegranskat)abstract
- A subtyping assay for both the hemagglutinin (HA) and neuraminidase (NA) surface antigens of the avian influenza virus (AIV) has been developed. The method uses padlock probe chemistry combined with a microarray output for detection. The outstanding feature of this assay is its capability to designate both the HA and the NA of an AIV sample from a single reaction mixture. A panel of 77 influenza virus strains was tested representing the entire assortment of the two antigens. One hundred percent (77/77) of the samples tested were identified as AIV, and 97% (75/77) were subtyped correctly in accordance with previous examinations performed by classical diagnostic methods. Testing of heterologous pathogens verified the specificity of the assay. This assay is a convenient and practical tool for the study of AIVs, providing important HA and NA data more rapidly than conventional methods.
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| 5. |
- Hägglund, Sara, et al.
(författare)
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Pathogenesis, Host Innate Immune Response, and Aerosol Transmission of Influenza D Virus in Cattle
- 2019
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Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 93
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Tidskriftsartikel (refereegranskat)abstract
- The recently discovered influenza D virus (IDV) of the Orthomyxoviridae family has been detected in swine and ruminants with a worldwide distribution. Cattle are considered to be the primary host and reservoir, and previous studies suggested a tropism of IDV for the upper respiratory tract and a putative role in the bovine respiratory disease complex. This study aimed to characterize the pathogenicity of IDV in naive calves as well as the ability of this virus to transmit by air. Eight naive calves were infected by aerosol with a recent French isolate, D/bovine/France/5920/2014. Results show that IDV replicates not only in the upper respiratory tract but also in the lower respiratory tract (LRT), inducing moderate bronchopneumonia with restricted lesions of interstitial pneumonia. Inoculation was followed by IDV-specific IgG1 production as early as 10 days postchallenge and likely both Th1 and Th2 responses. Study of the innate immune response in the LRT of IDV-infected calves indicated the overexpression of pathogen recognition receptors and of chemokines CCL2, CCL3, and CCL4, but without overexpression of genes involved in the type I interferon pathway. Finally, virological examination of three aerosol-sentinel animals, housed 3 m apart from inoculated calves (and thus subject to infection by aerosol transmission), and IDV detection in air samples collected in different areas showed that IDV can be airborne transmitted and infect naive contact calves on short distances. This study suggests that IDV is a respiratory virus with moderate pathogenicity and probably a high level of transmission. It consequently can be considered predisposing to or a cofactor of respiratory disease.IMPORTANCE Influenza D virus (IDV), a new genus of the Orthomyxoviridae family, has a broad geographical distribution and can infect several animal species. Cattle are so far considered the primary host for IDV, but the pathogenicity and the prevalence of this virus are still unclear. We demonstrated that under experimental conditions (in a controlled environment and in the absence of coinfecting pathogens), IDV is able to cause mild to moderate disease and targets both the upper and lower respiratory tracts. The virus can transmit by direct as well as aerosol contacts. While this study evidenced overexpression of pathogen recognition receptors and chemokines in the lower respiratory tract, IDV-specific IgG1 production as early as 10 days postchallenge, and likely both Th1 and Th2 responses, further studies are warranted to better understand the immune responses triggered by IDV and its role as part of the bovine respiratory disease complex.
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| 6. |
- Linde, Anna-Malin, et al.
(författare)
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Complete genome characterisation of a Newcastle disease virus isolated during an outbreak in Sweden in 1997
- 2010
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Ingår i: Virus Genes. - : Springer Science and Business Media LLC. - 0920-8569 .- 1572-994X. ; 41, s. 165-173
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Tidskriftsartikel (refereegranskat)abstract
- The complete genome sequence of a Newcastle disease virus (NDV) isolated from a chicken in Sweden was determined and compared with other NDV sequences. The isolate was shown to belong to genotype VIIb, which arose in the Far East and spread around the world during the 1990s. It had a length of 15,192 bases and consisted of six genes in the order 3'-NP-P-M-F-HN-L-5'. The F protein cleavage site was 112-RRQRRF-117, corresponding to that of a virulent pathotype.
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| 7. |
- Metreveli, Giorgi, et al.
(författare)
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Comparison of two H1N2 swine influenza A viruses from disease outbreaks in pigs in Sweden during 2009 and 2010
- 2011
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Ingår i: Virus Genes. - : Springer Science and Business Media LLC. - 0920-8569 .- 1572-994X. ; 42, s. 236-244
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Tidskriftsartikel (refereegranskat)abstract
- The influenza A virus subtypes H1N1, H1N2 and H3N2 are prevalent in pig populations worldwide. In the present study, two relatively uncommon swine influenza virus (SIV) H1N2 subtypes, isolated in Sweden in 2009 and 2010, were compared regarding their molecular composition and biological characteristics. The differences regarding markers purportedly related to pathogenicity, host adaptation or replication efficiency. They included a truncated PB1-F2 protein in the earlier isolate but a full length version in the more recent one; differences in the number of haemagglutinin glycosylation sites, including a characteristic human one; and a nuclear export protein with altered export signal. Of particular interest, the NS1 amino acid sequence of swine H1N2-2009 and 2010 has a 'unique or very unusual' PDZ binding domain (RPKV) at the C-terminal of the protein, a motif that has been implicated as a virulence marker. Concerning biological properties, these viruses reached lower titre and showed reduced cytopathogenicity in MDCK cells compared with an avian-like H1N1 isolate A/swine/Lidkoping/1193/2002 belonging to the same lineage as the 2009 and 2010 isolates. The findings should contribute to better understanding of factors related to the survival/extinction of this uncommon reassortant variant.
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| 8. |
- Metreveli, Giorgi, et al.
(författare)
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Phylogenetic Analysis of the Hemagglutinin Gene of Low Pathogenic Avian Influenza Virus H7N7 Strains in Mallards in Northern Europe
- 2010
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Ingår i: Avian Diseases. - 0005-2086. ; 54, s. 453-456
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Tidskriftsartikel (refereegranskat)abstract
- The H7 subtype of avian influenza (AI) has the capability to evolve into a highly pathogenic AI (HPAI) virus. In this study, we have characterized the hemagglutinin (HA) genes of three avian H7N7 influenza A viruses isolated from healthy migratory, mallards in Northern Europe in three different years to study the natural variation of these viruses in the natural reservoir. Phylogenetic analysis demonstrated that the H7 HA genes were all closely related to recent H7 isolates responsible for influenza outbreaks in poultry in Europe. The A/mallard/Sweden/S90735/2003 isolate clustered together with the HA gene of A/ mallard/Netherlands/12/00/H7N3 (AY338460), which has been shown to be closely related to the H7N7 responsible for HPAI outbreaks in the Netherlands and Germany in 2003. In contrast, the HA gene of the two mallard strains A/mallard/Sweden/S90597/2005 and A/mallard/Sweden/100993/2008 were more related to the chicken strain isolated in domestic poultry in England in 2006, A/Ch/England/4054/2006/H7N3 (EF467826), and 2008, A/Ch/England/2008/1-17N7 (214011964). Analysis of the deduced HA amino acid sequence shows two different HA cleavage sires in these isolates. Although these HA cleavage sites are consistent with a low pathogenicity AI, the cleavage sites appear to posses an increasing numbers of basic amino acids over time (PEIPKGRGLF in 2003 and 2005 and PEIPKKRGLF in 2008). The conclusion from this study is that H7 subtypes isolated from healthy mallards are closely related to the H7 subtypes that have caused recent influenza outbreaks in poultry, in Europe.
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| 9. |
- Munir, Muhammad, et al.
(författare)
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Alleles A and B of non-structural protein 1 of avian influenza A viruses differentially inhibit beta interferon production in human and mink lung cells
- 2011
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Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 92, s. 2111-2121
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Tidskriftsartikel (refereegranskat)abstract
- Non-structural protein 1 (NS1) counteracts the production of host type I interferons (IFN-alpha/beta) for the efficient replication and pathogenicity of influenza A viruses. Here, we reveal another dimension of the NS1 protein of avian influenza A viruses in suppressing IFN-beta production in cultured cell lines. We found that allele A NS1 proteins of H6N8 and H4N6 have a strong capacity to inhibit the activation of IFN-beta production, compared with allele B from corresponding subtypes, as measured by IFN stimulatory response element (ISRE) promoter activation, IFN-beta mRNA transcription and IFN-beta protein expression. Furthermore, the ability to suppress IFN-beta promoter activation was mapped to the C-terminal effector domain (ED), while the RNA-binding domain (RBD) alone was unable to suppress IFN-beta promoter activation. Chimeric studies indicated that when the RBD of allele A was fused to the ED of allele B, it was a strong inhibitor of IFN-beta promoter activity. This shows that well-matched ED and RBD are crucial for the function of the NS1 protein and that the RBD could be one possible cause for this differential IFN-beta inhibition. Notably, mutagenesis studies indicated that the F103Y and Y103F substitutions in alleles A and B, respectively, do not influence the ISRE promoter activation. Apart from dsRNA signalling, differences were observed in the expression pattern of NS1 in transfected human and mink lung cells. This study therefore expands the versatile nature of the NS1 protein in inhibiting IFN responses at multiple levels, by demonstrating for the first time that it occurs in a manner dependent on allele type.
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| 10. |
- Munir, Muhammad, et al.
(författare)
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Detection and Phylogenetic Analysis of Peste des Petits Ruminants Virus Isolated from Outbreaks in Punjab, Pakistan
- 2012
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Ingår i: Transboundary and Emerging Diseases. - : Hindawi Limited. - 1865-1674 .- 1865-1682. ; 59, s. 85-93
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Tidskriftsartikel (refereegranskat)abstract
- Peste des Petits Ruminants (PPR) is an important viral disease of small ruminants and is endemic in Pakistan. In the following study, samples from two outbreaks of PPR in goats have been subjected to laboratory investigations. The Peste des Petits Ruminants virus (PPRV) genome was detected using both conventional and real-time PCR. Genetic characterization of the local PPRV field isolates was conducted by sequencing 322 bp of the fusion (F) gene and 255 bp of the nucleoprotein (N) gene. The phylogenetic tree based on the F gene clustered samples from both outbreaks into lineage 4 along with other Asian isolates, specifically into subcluster 1 along with isolates from Middle East. Analysis of N gene revealed a different pattern. In this case, the Pakistani samples clustered with Chinese, Tajikistani and Iranian isolates, which probably represents the true geographical pattern of virus circulation. This is the first report presenting the phylogenetic tree based on N gene as well as performing a parallel comparison of the trees of F and N gene together from Pakistani isolates. The results of this study shed light on the PPRV population in Pakistan and emphasize the importance of using molecular methods to understand the epidemiology. Such understanding is essential in any efforts to control the number and impact of outbreaks that are occurring in endemic countries such as Pakistan, especially in the current scenario where OIE and FAO are eager to control and subsequently eradicate PPR from the globe, as has been achieved for Rinderpest.
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| 11. |
- Munir, Muhammad, et al.
(författare)
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Double-Stranded RNA-Induced Activation of Activating Protein-1 Promoter Is Differentially Regulated by the Non-structural Protein 1 of Avian Influenza A Viruses
- 2012
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Ingår i: Viral Immunology. - : Mary Ann Liebert Inc. - 0882-8245 .- 1557-8976. ; 25, s. 79-85
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Tidskriftsartikel (refereegranskat)abstract
- Non-structural protein 1 (NS1) of influenza A viruses is a multifunctional protein that antagonizes the host immune response by interfering with several host signaling pathways. Based on putative amino acid sequences, NS1 proteins are categorized into two gene pools, allele A and allele B. Here we identified that allele A NS1 proteins of H6N8 and H4N6 are able to inhibit double-stranded RNA (dsRNA)-induced activating protein-1 (AP-1) promoter in cultured cell lines (human A549 and mink lung cells). Allele B NS1 proteins from corresponding subtypes of influenza A viruses are weak in this inhibition, despite significant levels of expression of each NS1 protein in human A549 cells. Furthermore, the capability to inhibit AP-1 promoter was mapped in the effector domain, since RNA binding domain alone lost its ability to inhibit this promoter activation. Chimeric forms of NS1 protein, composed of either RNA binding domain of allele A or B and effector domain of allele A or B, showed comparable inhibition to that of their wild-type NS1 proteins, or to the effector domain of corresponding NS1 proteins. Both alleles A and B NS1 proteins of H6N8 and H4N6 were expressed to significant levels, and were localized predominantly in the nucleus of human A549 cells. These results underscore the importance of the effector domain in inhibiting AP-1 promoter activation, and the biological function of the effector domain in stabilizing the RNA binding domain. Further, we revealed the versatile nature of NS1 in inhibiting the AP-1 transcription factor, in a manner dependent on allele type. Comprehensive studies, focusing on the molecular mechanisms behind this differential inhibition, may facilitate exploration of the zoonotic and pathogenic potential of influenza A viruses.
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| 12. |
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| 13. |
- Munir, Muhammad, et al.
(författare)
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Newcastle Disease Virus in Pakistan: Genetic Characterization and Implication in Molecular Diagnosis
- 2012
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Ingår i: Indian Journal of Virology. - : Springer Science and Business Media LLC. - 0970-2822 .- 0974-0120. ; 23, s. 368-373
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Tidskriftsartikel (refereegranskat)abstract
- Newcastle disease (ND) is a fatal and contagious disease that poses a constant threat to the poultry industry around the globe. Due to the complex clinico-pathological picture and high genetic variability, the efficient diagnosis of NDV strains is a challenge. In an emerging wave of ND in the north of Pakistan, samples from six outbreaks in commercial poultry and two from healthy backyard poultry flocks were screened for NDV. A real-time PCR based on the fusion and polymerase genes of NDV detected all six isolates whereas a validated real-time PCR based on the matrix gene failed to detect any of these isolates, most likely due to substantial mismatches in the probe-binding site. All isolates have shown ICPI and MDT values similar to the velogenic form of NDV strains. The cleavage site in the F protein was found to be (112)RRQKRa dagger"F-117, typical of virulent NDV. Phylogenetic reconstruction, based on fusion and matrix genes, provided enough evidences to consider these isolates as a new subgenotype within genotype VII. This study raised concerns about the genetic variability of NDV circulating in Pakistan, and sensitivity of the assays for the detection of the NDV isolates in clinical samples.
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| 14. |
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| 15. |
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| 16. |
- Munir, Muhammad, et al.
(författare)
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Whole genome sequencing and characterization of a virulent Newcastle disease virus isolated from an outbreak in Sweden
- 2011
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Ingår i: Virus Genes. - : Springer Science and Business Media LLC. - 0920-8569 .- 1572-994X. ; 43, s. 261-271
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the complete genome sequence of a Newcastle disease virus (NDV) isolate collected from an outbreak in 1995 in chickens was fully characterized and compared with other NDV sequences. The genome was found to be 15,192 nucleotides long and to consist of six genes in the order 3'-NP-P-M-F-HN-L-5', similar to other avian paramyxoviruses type-I. However, a six-nucleotide insertion was observed in the 5' non-coding regions of the nucleoprotein (NP) gene, a feature that is unique to some NDV isolates. The isolate shows the amino acid sequence (112)RRQKRF(117) at the cleavage site of the F protein, which is identical to a known motif for virulent pathotypes of NDV. The phylogenetic analysis of the coding region of the F gene indicated that this isolate belongs to genotype VI, more specifically to genotype VId, along with isolates from the other European countries (Denmark, Switzerland and Austria). The same genotype caused outbreaks in the Middle East and Greece in the late 1960s, and in Hungary, in the early 1980s, suggesting a common source for these outbreaks.
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| 17. |
- Naguib, Mahmoud, et al.
(författare)
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Global patterns of avian influenza A (H7) : virus evolution and zoonotic threats
- 2019
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Ingår i: FEMS Microbiology Reviews. - : Oxford University Press. - 0168-6445 .- 1574-6976. ; 43:6, s. 608-621
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Forskningsöversikt (refereegranskat)abstract
- Avian influenza viruses (AIVs) continue to impose a negative impact on animal and human health worldwide. In particular, the emergence of highly pathogenic AIV H5 and, more recently, the emergence of low pathogenic AIV H7N9 have led to enormous socioeconomical losses in the poultry industry and resulted in fatal human infections. While H5N1 remains infamous, the number of zoonotic infections with H7N9 has far surpassed those attributed to H5. Despite the clear public health concerns posed by AIV H7, it is unclear why specifically this virus subtype became endemic in poultry and emerged in humans. In this review, we bring together data on global patterns of H7 circulation, evolution and emergence in humans. Specifically, we discuss data from the wild bird reservoir, expansion and epidemiology in poultry, significant increase in their zoonotic potential since 2013 and genesis of highly pathogenic H7. In addition, we analysed available sequence data from an evolutionary perspective, demonstrating patterns of introductions into distinct geographic regions and reassortment dynamics. The integration of all aspects is crucial in the optimisation of surveillance efforts in wild birds, poultry and humans, and we emphasise the need for a One Health approach in controlling emerging viruses such as AIV H7.
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| 18. |
- Nordling, Dag, et al.
(författare)
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Reproductive effort reduces specific immune response and parasite resistance
- 1998
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Ingår i: Proceedings of the Royal Society of London: Biological sciences. ; :265, s. 1291-1298
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: If a trade-off exists between reproductive effort and immune function, life-history decisions may have important implications for parasite resistance. Here, we report effects of experimental manipulation of reproductive effort on subsequent specific immune function and parasite resistance in the collared flycatcher,, Ficedula albicollis. Our results show that increased reproductive effort of females immunized with Newcastle disease virus (NDV) vaccine negatively affected the ability to respond with NDV-specific antibodies. We further show that increased reproductive effort increased the intensity of Haemoproteus infections and that such infections are associated with higher mortality. Our results thus provide support for the hypothesis that immune suppression caused by reproductive effort may be an important mechanism mediating the life-history cost of reproduction.
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| 19. |
- Näslund, Katarina, et al.
(författare)
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Authors’ response
- 2020
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Ingår i: Journal of Veterinary Diagnostic Investigation. - : SAGE Publications. - 1040-6387 .- 1943-4936. ; 32, s. 633-634
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 20. |
- Näslund, Katarina, et al.
(författare)
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Seroprevalence of influenza D virus in bulls in Argentina
- 2020
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Ingår i: Journal of Veterinary Diagnostic Investigation. - : SAGE Publications. - 1040-6387 .- 1943-4936. ; 32, s. 585-588
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Tidskriftsartikel (refereegranskat)abstract
- Influenza D virus (IDV) is considered a new agent involved in bovine respiratory disease (BRD). Based on seroprevalence studies or isolation from clinical samples, this virus has been detected on several continents and in several animal species, including cattle, pigs, camel, horses, and goats. We used an indirect in-house ELISA to detect anti-IDV antibodies in 165 serum samples from bulls on 116 farms in the province of La Pampa, Argentina. Eighty-five of 116 (73%) farms had at least 1 positive animal, and 112 of 165 (68%) of the analyzed samples were positive. There were no significant differences in the proportion of seropositive samples depending on the geographic region in which the samples were taken. Our results suggest that IDV infection is endemic in La Pampa; the clinical importance of IDV in Argentina remains to be investigated.
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| 21. |
- Osbjer, Kristina, et al.
(författare)
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Influenza A Virus in Backyard Pigs and Poultry in Rural Cambodia
- 2017
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Ingår i: Transboundary and Emerging Diseases. - : WILEY. - 1865-1674 .- 1865-1682. ; 64:5, s. 1557-1568
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Tidskriftsartikel (refereegranskat)abstract
- Surveillance of influenza virus in humans and livestock is critical, given the worldwide public health threats and livestock production losses. Livestock farming involving close proximity between humans, pigs and poultry is often practised by smallholders in low-income countries and is considered an important driver of influenza virus evolution. This study determined the prevalence and genetic characteristics of influenza A virus (IAV) in backyard pigs and poultry in Cambodia. A total of 751 animals were tested by matrix gene-based rRT-PCR, and influenza virus was detected in 1.5% of sampled pigs, 1.4% of chickens and 1.0% of ducks, but not in pigeons. Full-length genome sequencing confirmed triple reassortant H3N2 in all IAV-positive pigs and various low pathogenic avian influenza subtypes in poultry. Phylogenetic analysis of the swine influenza viruses revealed that these had haemagglutinin and neuraminidase genes originating from human H3N2 viruses previously isolated in South-East Asia. Phylogenetic analysis also revealed that several of the avian influenza subtypes detected were closely related to internal viral genes from highly pathogenic H5N1 and H9N2 formerly sequenced in the region. High sequence homology was likewise found with influenza A viruses circulating in pigs, poultry and wild birds in China and Vietnam, suggesting transboundary introduction and cocirculation of the various influenza subtypes. In conclusion, highly pathogenic subtypes of influenza virus seem rare in backyard poultry, but virus reassortment, involving potentially zoonotic and pandemic subtypes, appears to occur frequently in smallholder pigs and poultry. Increased targeted surveillance and monitoring of influenza circulation on smallholdings would further improve understanding of the transmission dynamics and evolution of influenza viruses in humans, pigs and poultry in the Mekong subregion and could contribute to limit the influenza burden.
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| 22. |
- Schlingemann, Joerg, et al.
(författare)
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Novel means of viral antigen identification : Improved detection of avian influenza viruses by proximity ligation
- 2010
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Ingår i: Journal of Virological Methods. - : Elsevier BV. - 0166-0934 .- 1879-0984. ; 163:1, s. 116-122
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Tidskriftsartikel (refereegranskat)abstract
- Recent outbreaks of avian influenza in different parts of the world have caused major economic losses for the poultry industry, affected wildlife seriously and present a significant threat even to human public health, due to the risk for zoonotic transmission. The ability to recognize avian influenza viruses (AIVs) early is of paramount importance to ensure that appropriate measures can be taken quickly to contain the outbreak. In this study. the performance of a proximity ligation assay (PLA) for the detection of AIV antigens in biological specimens was evaluated. It is shown that PLA: (i) as a novel principle of highly sensitive antigen detection is extending the arsenal of tools for the diagnosis of AIV; (ii) is very specific, nearly as sensitive as a commonly used reference real-time PCR assay, and four orders of magnitude more sensitive than a sandwich ELISA, utilizing the same antibody; (iii) avoids the necessity of nucleic acids extraction, which greatly facilitates high-throughput implementations; (iv) allows the use of inactivated samples, which safety can be transported from the field to diagnostic laboratories for further analysis. In summary, the results demonstrate that PLA is suited for rapid, accurate and early detection of AIV.
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| 23. |
- Ståhl, Karl, et al.
(författare)
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The first reported Florida Clade 1 virus in the Nordic countries, isolated from a Swedish outbreak of equine influenza in 2011
- 2016
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 184, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Equine Influenza Virus (EIV) is a major cause of respiratory disease in horses and the virus constantly undergoes antigenic drift. Here we characterize and describe the HA1 and the NA genes of H3N8 within samples obtained from outbreaks in Sweden during November-December 2011. Both Clade 1 and Clade 2 viruses of the Florida sublineage were identified. The index case of Clade 2 was transported to Sweden from Spain through the Netherlands, whereas the Clade 1 had its origin from a Swedish stud farm. The Clade 1 virus was efficiently spread between training yards by unvaccinated young horses, but vaccinated horses were also presented with clinical signs of respiratory disease. No virus of the Eurasian lineage was isolated during this outbreak. Clade 1 has previously been described in outbreaks in numerous of other countries, but this is the first time it has been detected in Sweden. The results from this study shows the importance of including both Clade 1 and Clade 2 of the Florida sublineage in equine influenza vaccines, supporting the ESP and OIE recommendations. (C) 2016 Published by Elsevier B.V.
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| 24. |
- Tolf, Conny, et al.
(författare)
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Prevalence of avian paramyxovirus type 1 in Mallards during autumn migration in the western Baltic Sea region
- 2013
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Ingår i: Virology Journal. - 1743-422X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Newcastle disease virus (NDV) is the causative agent of the Newcastle disease, a severe disease in birds associated with substantial economic losses to the poultry industry worldwide. Sweden is situated along the Western European waterfowl flyway and applies a non-vaccination policy combined with directives of immediate euthanisation of NDV infected flocks. During the last decades there have been several outbreaks with NDV in poultry in Sweden. However, less is known about the virus prevalence in the wild bird population including waterfowl, a well-established reservoir of avian paramyxovirus type 1 (APMV-1), the paramyxovirus serotype that include pathogenic NDV. Methods: The survey constituted of 2332 samples from Mallards (Anas platyrhynchos), trapped in the southern part of Sweden during autumn migration in 2010. These samples were screened for APMV-1 by real-time reverse transcription PCR, and viral strains from positive samples were isolated and characterized by sequence analysis of the fusion gene and by phylogenetic analysis. Conclusions: Twenty of these samples were positive for APMV-1, hence a virus prevalence of 0.9% (95% Confidence Interval [95% CI]=0.54%, 1.35%). The highest APMV-1 prevalence was detected in juvenile Mallards sampled in November (n=887, prevalence 1.24% ([95% CI])=0.67%, 2.24%). Sequence analysis and evaluation of phylogenetic relatedness indicated that isolated APMV-1 strains were lentogenic, and phylogenetically most closely related to genotype Ib strains within the clade of class II viruses. The sampling system employed enabled us to follow APMV-1 infections and the shedding of one particular viral strain in one individual bird over several days. Furthermore, combining previous screening results with the APMV-1 detections in this study showed that more than 50% of Mallards that tested positive for APMV-1 RNA were co-infected with influenza A virus.
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| 25. |
- Yacoub, A., et al.
(författare)
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The rapid molecular subtyping and pathotyping of avian influenza viruses
- 2009
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Ingår i: Journal of Virological Methods. - : Elsevier BV. - 0166-0934 .- 1879-0984. ; 156:1-2, s. 157-161
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Tidskriftsartikel (refereegranskat)abstract
- Highly conserved nucleotide stretches flanking the cleavage site of the haemagglutinin (HA) gene of influenza type A viruses were utilised for generating PCR amplicons from a broad range of avian influenza viruses (AIV) in a one-step real-time SYBR Green RT-PCR assay. The nucleotide sequencing of the amplified PCR products simultaneously reveals both the HA subtype and the pathotype of the AIV isolates, as we demonstrated in case of H5 subtype viruses. The specificity of the assay was confirmed by investigating 66 strains of AIV and nine heterologous pathogens, including influenza B, C and various avian pathogenic viruses. This assay enables a general HA subtype identification and pathotype determination of AIV isolates providing a useful alternative tool for avian influenza diagnosis.
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| 26. |
- Zohari, Siamak, et al.
(författare)
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Avian influenza A(H10N7) virus involvement in mass mortality of harbour seals (Phoca vitulina) in Sweden, March through October 2014
- 2014
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Ingår i: Eurosurveillance. - 1025-496X .- 1560-7917. ; 19:46, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- We provide the first scientific report of influenza A virus involvement in a mass mortality event among harbour seals (Phoca vitulina) off the west coast of Sweden. Avian influenza A (H10N7) virus was detected in the lungs of two affected animals. This subtype has not been reported in seals to date, nor has influenza A-associated mortality been reported in seals in Europe. Circulation of avian influenza viruses in mammals may have implications for public health.
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| 27. |
- Zohari, Siamak, et al.
(författare)
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Full genome comparison and characterization of avian H10 viruses with different pathogenicity in Mink (Mustela vison) reveals genetic and functional differences in the non-structural gene
- 2010
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Ingår i: Virology Journal. - 1743-422X. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: The unique property of some avian H10 viruses, particularly the ability to cause severe disease in mink without prior adaptation, enabled our study. Coupled with previous experimental data and genetic characterization here we tried to investigate the possible influence of different genes on the virulence of these H10 avian influenza viruses in mink.Results: Phylogenetic analysis revealed a close relationship between the viruses studied. Our study also showed that there are no genetic differences in receptor specificity or the cleavability of the haemagglutinin proteins of these viruses regardless of whether they are of low or high pathogenicity in mink. In poly I: C stimulated mink lung cells the NS1 protein of influenza A virus showing high pathogenicity in mink down regulated the type I interferon promoter activity to a greater extent than the NS1 protein of the virus showing low pathogenicity in mink.Conclusions: Differences in pathogenicity and virulence in mink between these strains could be related to clear amino acid differences in the non structural 1 (NS1) protein. The NS gene of mink/84 appears to have contributed to the virulence of the virus in mink by helping the virus evade the innate immune responses.
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| 28. |
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| 29. |
- Zohari, Siamak, et al.
(författare)
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Isolation and characterization of low pathogenic H9N2 avian influenza A viruses from a healthy flock and its comparison to other H9N2 isolates
- 2013
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Ingår i: Indian Journal of Virology. - : Springer Science and Business Media LLC. - 0970-2822 .- 0974-0120. ; 24, s. 342-348
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Tidskriftsartikel (refereegranskat)abstract
- Several outbreaks of avian influenza (AI) caused by H9N2 subtype, have been reported in the poultry industry during 1990 around the globe. Currently, H9N2 are endemic in the large area of Middle and Far East, including Pakistan. Since H9N2 AI viruses are sporadically reported from humans, extensive incidence of H9N2 in poultry imposes a great risk for human health. In this context, continuous monitoring of the poultry and determining the genetic nature of these viruses are fundamental to predict any future threat. Thus gene sequences of one isolate of H9N2, isolated from commercial poultry flocks, were analyzed. The results of this investigation, based on hemagglutinin (HA), neuraminidase (NA) and non-structural genes, showed that Pakistani H9N2 isolates are closely related to each other and to other H9N2 isolates from the Middle East. However, several unusual substitutions with unknown functional consequences were observed in HA and NA proteins and thus warrant further investigations for their possible role in viral biology. In conclusion, these findings provide information regarding the genetic nature of H9N2 avian influenza viruses in Pakistani poultry and necessitate the sequencing of more H9N2 viruses from both naturally infected and vaccinated flocks.
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| 30. |
- Zohari, Siamak, et al.
(författare)
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Pathology of natural highly pathogenic avian influenza H5N1 infection in wild tufted ducks (Aythya fuligula)
- 2009
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Ingår i: Journal of Veterinary Diagnostic Investigation. - : SAGE Publications. - 1040-6387 .- 1943-4936. ; 21, s. 579-587
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Tidskriftsartikel (refereegranskat)abstract
- Highly pathogenic avian influenza (HPAI) Subtype H5N1 is an infectious systemic viral disease that results in high morbidity and mortality in poultry, and has been reported in a wide range of wild bird species during the last few years. An outbreak of HPAI H5N1 occurred in wild birds in Sweden in 2006 that affected several duck species, geese, swans, gulls, and raptors. Tufted ducks (Aythya fuligula) accounted for the largest number of positive cases and, therefore, were selected for more in-depth histologic and immunohistochemical evaluations. The main histologic lesions associated with the presence of avian influenza antigen were found in the brain, pancreas, and upper respiratory tract. Other tissues in which influenza antigen was variably found included liver, lung, adrenal glands, kidneys, and peripheral nerve ganglia. The current study describes the pathology and viral tissue targeting of H5N1 by using histology, polymerase chain reaction, and immunohistochemistry, and highlights the range and variation in the presentation of the natural disease in tufted ducks.
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| 31. |
- Zohari, Siamak, et al.
(författare)
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Phylogenetic analysis of the non-structural (NS) gene of influenza A viruses isolated from mallards in Northern Europe in 2005
- 2008
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Ingår i: Virology Journal. - 1743-422X. ; 5:Article ID: 147
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although the important role of the non-structural 1 (NS) gene of influenza A in virulence of the virus is well established, our knowledge about the extent of variation in the NS gene pool of influenza A viruses in their natural reservoirs in Europe is incomplete. In this study we determined the subtypes and prevalence of influenza A viruses present in mallards in Northern Europe and further analysed the NS gene of these isolates in order to obtain a more detailed knowledge about the genetic variation of NS gene of influenza A virus in their natural hosts. Results: A total number of 45 influenza A viruses of different subtypes were studied. Eleven haemagglutinin-and nine neuraminidase subtypes in twelve combinations were found among the isolated viruses. Each NS gene reported here consisted of 890 nucleotides; there were no deletions or insertions. Phylogenetic analysis clearly shows that two distinct gene pools, corresponding to both NS allele A and B, were present at the same time in the same geographic location in the mallard populations in Northern Europe. A comparison of nucleotide sequences of isolated viruses revealed a substantial number of silent mutations, which results in high degree of homology in amino acid sequences. The degree of variation within the alleles is very low. In our study allele A viruses displays a maximum of 5% amino acid divergence while allele B viruses display only 2% amino acid divergence. All the viruses isolated from mallards in Northern Europe possessed the typical avian ESEV amino acid sequence at the C-terminal end of the NSI protein. Conclusion: Our finding indicates the existence of a large reservoir of different influenza A viruses in mallards population in Northern Europe. Although our phylogenetic analysis clearly shows that two distinct gene pools, corresponding to both NS allele A and B, were present in the mallards populations in Northern Europe, allele B viruses appear to be less common in natural host species than allele A, comprising only about 13% of the isolates sequenced in this study.
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| 32. |
- Zohari, Siamak, et al.
(författare)
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Serologic and virologic screening of paramyxovirus type 1 and avian influenza virus (H5∓mp;H7) in wild migratory birds in Sweden (preliminary study)
- 2001
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Ingår i: Proceedings of the joint seventh annual meetings of the national Newcastle disease and avian influenza laboratories of countries of the European Union.
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Konferensbidrag (refereegranskat)abstract
- Following outbreaks of Newcastle disease in 1995 and 1997 in Sweden, and anoutbreak of highly pathogenic avian influenza (HPAI) in Northern Italy during thewinter of 1999/2000 a study was initiated to evaluate the presence of paramyxovirustype 1 (PMV-1) and avian influenza viruses (H5&H7) (AIV) in the wild avifauna inSweden.Materials and MethodsThe study was performed during the spring of 2000. In total, 150 serum samples and120 cloacal swabs were obtained from 53 migrating bird species (orders Anseriformes,Charadriiformes, Columbiformes, Strigiformes, Piciformes and Passerinformes) (Table1) at Ottenby Bird Station on southern Öland (an island in the Baltic off the south-eastcoast of Sweden). The swabs were obtained from the same, but not all, individual birdsas the serum samples. The bird species were selected based on their winter habitat, inorder to sample migratory birds which were likely to have either spent the previouswinter in Italy or visited Italy while migrating northwards. Additionally, cloacal swabsfrom Anseriformes in southern Sweden will be analysed during the spring of 2001.The serum samples were tested by hemagglutination-inhibition test for the presence ofantibodies to AIV, and by a blocking ELISA (SVANOVIR Svanova Biotech,Uppsala, Sweden) for antibodies to PMV-1. All cloacal swabs were cultured accordingto Council directive 92/66/EEC and 92/40/EEC. Following each of the three passagesthe allantoic fluid was tested for hemagglutinating (HA) virus.ResultsOne serum sample from a Ringed Plover (Charadrius hiaticula) showed a low titer(1:16) against AIV (H5). None of the serum samples were positive for PMV-1, howeverthree Ringed Plovers showed PI-values of 40%. No cloacal swabs were available fromthese four birds. No viruses were isolated from any of the cloacal swabs.
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