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  • 51.
    Griekspoor, Petra
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Campylobacter jejuni in penguins, Antarctica2009In: Emerging Infectious Diseases, ISSN 1080-6040, E-ISSN 1080-6059, Vol. 15, no 5, p. 847-849Article in journal (Refereed)
  • 52.
    Griekspoor, Petra
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olsson Engvall, Eva
    National Veterinary Institute.
    Åkerlind, Britt
    Linköping University.
    Olsen, Björn
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Genetic diversity and host associations in Campylobacter jejuni from human cases and broilers in 2000 and 20082015In: Veterinary Microbiology, ISSN 0378-1135, E-ISSN 1873-2542, Vol. 178, no 1-2, p. 94-98Article in journal (Refereed)
    Abstract [en]

    Campylobacter jejuni is an important food-borne pathogen, with a global distribution. It can colonize numerous host species, including both domestic and wild animals, but is particularly associated with birds (poultry and wild birds). For human campylobacteriosis, poultry products are deemed the most significant risk factor for acquiring infection. We conducted a genotyping and host attribution study of a large representative collection of C. jejuni isolated from humans and broilers in Sweden in the years 2000 and 2008. In total 673 broiler and human isolates from 10 different abattoirs and 6 different hospitals were genotyped with multilocus sequence typing. Source attribution analyses confirmed the strong linkage between broiler C. jejuni and domestic human cases, but also indicated a significant association to genotypes more commonly found in wild birds. Genotype distributions did not change dramatically between the two study years, suggesting a stable population of infecting bacteria.

  • 53. Guan, Y.
    et al.
    Webby, R.
    Capua, I.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    H5N1: How to track a flu virus2012In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 483, no 7391, p. 535-536Article in journal (Refereed)
  • 54.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University.
    Elmberg, Johan
    Kristianstad University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Trends in body mass of ducks over time: the hypotheses in Guillemain et al. revisited.2011In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, no 3, p. 338-340Article in journal (Refereed)
  • 55.
    Gunnarsson, Gunnar
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Jourdain, Elsa
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Helander, Björn
    Lindberg, Peter
    Elmberg, Johan
    Latorre-Margalef, Neus
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Zero prevalence of influenza A virus two raptor species by standard screeing.2009In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 10, no 4, p. 387-390Article in journal (Refereed)
    Abstract [en]

    Disease can have severe impact on animal populations, especially in rare species. Baseline data for atypical host species are missing for a range of infectious diseases, although such hosts are potentially more affected than the normal vectors and reservoir species. If highly pathogenic avian influenza strikes rare birds of prey, this may have crucial impact on the predator species itself, but also on the food web in which it interacts. Here we present the first large-scale screening of raptors that regularly consume birds belonging to the natural reservoir of influenza A viruses. Influenza A virus prevalence was studied in two rare raptors, the white-tailed sea eagle (Haliaeetus albicilla) and the peregrine falcon (Falco peregrinus). Nestlings were screened for active (181 white-tailed sea eagles and 168 peregrine falcons) and past (123 white-tailed sea eagles and 6 peregrine falcons) infection in 2006–2007, and an additional 20 succumbed adult white-tailed sea eagles were sampled in 2003–2006. Neither high- nor low-pathogenic influenza infections were found in our sample, but this does not rule out that the former may have major impact on rare raptors and their food webs.

  • 56.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hobson, K. A.
    Environment Canada, Saskatoon, Canada.
    Van Wilgenburg, S. L.
    Environment Canada, Saskatoon, Canada.
    Elmberg, Johan
    Kristianstad University.
    Olsen, Björn
    Uppsala University Hospital.
    Fouchier, R. A. M.
    Erasmus Medical Center, The Netherlands.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Disease Dynamics and Bird Migration – Linking Mallards Anas platyrhynchos and subtype diversity of Influenza A Virus in Time and Space2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 4, article id e35679Article in journal (Refereed)
    Abstract [en]

    The mallard Anas platyrhynchos is a reservoir species for influenza A virus in the northern hemisphere, with particularly high prevalence rates prior to as well as during its prolonged autumn migration. It has been proposed that the virus is brought from the breeding grounds and transmitted to conspecifics during subsequent staging during migration, and so a better understanding of the natal origin of staging ducks is vital to deciphering the dynamics of viral movement pathways. Ottenby is an important stopover site in southeast Sweden almost halfway downstream in the major Northwest European flyway, and is used by millions of waterfowl each year. Here, mallards were captured and sampled for influenza A virus infection, and positive samples were subtyped in order to study possible links to the natal area, which were determined by a novel approach combining banding recovery data and isotopic measurements (d2 H) of feathers grown on breeding grounds. Geographic assignments showed that the core natal areas of studied mallards were in Estonia, southern and central Finland, and northwestern Russia. This study demonstrates a clear temporal succession of latitudes of natal origin during the course of autumn migration. We also demonstrate a corresponding and concomitant shift in virus subtypes. Acknowledging that these two different patterns were based in part upon different data, a likely interpretation worth further testing is that the early arriving birds with more proximate origins have different influenza A subtypes than the more distantly originating late autumn birds. If true, this knowledge would allow novel insight into the origins and transmission of the influenza A virus among migratory hosts previously unavailable through conventional approaches.

  • 57.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Fransson, Thord
    Direct and indirect effects of winter harshness on the survival of Mallards Anas platyrhynchos in northwest Europe2012In: Ibis, ISSN 0019-1019, E-ISSN 1474-919X, Vol. 154, no 2, p. 307-317Article in journal (Refereed)
    Abstract [en]

    To understand population dynamics it is necessary to understand vital rates, which may be affected by a wide range of factors including environmental variables such as weather. Weather conditions can affect birds vital rates directly through increased mortality due to impaired conditions, or indirectly via changes in body condition and/or behaviour. Most understanding of direct and indirect effects of weather comes from studies of breeding birds, whereas the situation in non-breeding periods is less clear. Here, we analysed annual survival of non-breeding Mallard Anas platyrhynchos, the most hunted waterfowl species in Europe, and assessed whether survival is related directly to winter harshness and/or indirectly via changes in winter recovery distributions. Recovery data on Mallards, initially marked in southeast Sweden, were analysed with an information-theoretic approach using program mark. Over 10 000 Mallards were marked in two time periods, 19641982 and 20022008, of which 13.3 and 4.7%, respectively, were later recovered. Mallards had lower annual survival in the early trapping period (0.580.63) than in the later period (0.690.71), with no clear effects of sex, age or year. Within each study period, winter harshness did not directly correlate with survival. However, milder winters may have contributed indirectly to higher survival in the second period, as winter harshness data were correlated with the distances to recovery positions for females, and also because winter recovery areas have shifted northeast during the past decades, possibly indicating a shortened migratory distance. Migration is costly, and there is therefore a likely linkage between migration behaviour and survival of dabbling ducks, in which direct as well as indirect effects of winter harshness may play a role. Other factors, such as hunting pressure, are also likely to have changed in the past decades, and may also have contributed to improved survival of Mallards in northwest Europe.

  • 58.
    Haemig, Paul D.
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sjöstedt de Luna, S
    Grafström, A
    Lithner, Stefan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lundkvist, Åke
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Kindberg, Jonas
    Stedt, Johan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Forecasting risk of tick-borne encephalitis (TBE): using data from wildlife and climate to predict next year's number of human victims.2011In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 43, no 5, p. 366-372Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Over the past quarter century, the incidence of tick-borne encephalitis (TBE) has increased in most European nations. However, the number of humans stricken by the disease varies from year to year. A method for predicting major increases and decreases is needed.

    METHODS: We assembled a 25-y database (1984-2008) of the number of human TBE victims and wildlife and climate data for the Stockholm region of Sweden, and used it to create easy-to-use mathematical models that predict increases and decreases in the number of humans stricken by TBE.

    RESULTS: Our best model, which uses December precipitation and mink (Neovison vison, formerly Mustela vison) bagging figures, successfully predicted every major increase or decrease in TBE during the past quarter century, with a minimum of false alarms. However, this model was not efficient in predicting small increases and decreases.

    CONCLUSIONS: Predictions from our models can be used to determine when preventive and adaptive programmes should be implemented. For example, in years when the frequency of TBE in humans is predicted to be high, vector control could be intensified where infested ticks have a higher probability of encountering humans, such as at playgrounds, bathing lakes, barbecue areas and camping facilities. Because our models use only wildlife and climate data, they can be used even when the human population is vaccinated. Another advantage is that because our models employ data from previously-established databases, no additional funding for surveillance is required.

  • 59.
    Haemig, Paul
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hernandez, Jorge
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bonnedahl, Jonas
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Barn Swallows (Hirundo rustica) Test Negative for Salmonella2008In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 8, p. 1-3Article in journal (Refereed)
  • 60.
    Haemig, Paul
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Stefan, Lithner
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sjöstedt de Luna, Sara
    Lundkvist, Åke
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hansson, Lennart
    Arneborn, Malin
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Red fox and tick-borne encephalitis (TBE) in humans: Can predators influence public health?2008In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 40, no 6-7, p. 527-532Article in journal (Refereed)
    Abstract [en]

    Analysing datasets from hunting statistics and human cases of tick-borne encephalitis (TBE), we found a positive correlation between the number of human TBE cases and the number of red fox (Vulpes vulpes). Time lags were also present, indicating that high numbers of red fox in 1 y translated into high numbers of human TBE cases the following y. Results for smaller predators were mixed and inconsistent. Hares and grouse showed negative correlations with human TBE cases, suggesting that they might function as dilution hosts. Combining our findings with food web dynamics, we hypothesize a diversity of possible interactions between predators and human disease – some predators suppressing a given disease, others enhancing its spread, and still others having no effect at all. Larger-sized predators that suppress red fox numbers and activity (i.e. wolf, Canis lupus; European lynx, Lynx lynx) were once abundant in our study area but have been reduced or extirpated from most parts of it by humans. We ask what would happen to red foxes and TBE rates in humans if these larger predators were restored to their former abundances.Read More: http://informahealthcare.com/doi/abs/10.1080/00365540701805446

  • 61.
    Haemig, Paul
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Roadside ecology and epidemiology of tick-borne diseases2008In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 40, no 11-12, p. 853-858Article in journal (Refereed)
    Abstract [en]

    When humans, pets and livestock walk along roads, they may encounter questing ticks and tick-borne pathogens. A new field of environmental science called road ecology can help researchers study the complex epidemiology of tick-borne diseases in the unique roadside environment. This paper reviews some of the important ways that roads alter the distribution, abundance and behaviour of wildlife species that are involved in the enzootic cycles of tick-borne diseases. Compared to the surrounding landscape, roadways often constitute a different environment and hence there is no assurance that disease risk along roads will be the same as in the adjacent landscape, or that disease control measures taken in the surrounding landscape will work in the adjacent roadway. Since roadways have their own special ecological conditions, are used extensively by the human populace and play strategic roles in community security, we believe that roadways should be one of the habitats where tick-borne diseases are studied. It is amazing that at this late period of human history, epidemiological research along such important corridors has been almost completely ignored.

  • 62.
    Hagman, Karl
    et al.
    Uppsala University.
    Barboutis, Christos
    Hellenic Ornithological Society, Greece;Natural History Museum of Crete, Greece.
    Ehrenborg, Christian
    Uppsala University.
    Fransson, Thord
    Swedish Museum of Natural History.
    Jaenson, Thomas G T
    Uppsala University.
    Lindgren, Per-Eric
    Linköping University.
    Lundkvist, Åke
    Uppsala University;Karolinska Institutet.
    Nyström, Fredrik
    Linköping University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Salaneck, Erik
    Uppsala University.
    On the potential roles of ticks and migrating birds in the ecology of West Nile virus2014In: Infection Ecology & Epidemiology, ISSN 2000-8686, E-ISSN 2000-8686, Vol. 4, article id 20943Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Mosquitoes are the primary vectors of West Nile virus (WNV). Ticks have, however, been suggested to be potential reservoirs of WNV. In order to investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northwards from Africa to Europe, were analyzed for the potential presence of WNV-RNA.

    METHODS: On the Mediterranean islands Capri and Antikythira a total of 14,824 birds were captured and investigated from which 747 ticks were collected.

    RESULTS AND CONCLUSION: Most of the identified ticks (93%) were nymphs and larvae of Hyalomma marginatum sensu lato, most of which were or appear to be Hyalomma rufipes. Of these ticks 729 were individually screened for WNV-RNA. None of the ticks was found to be WNV positive. Thus, there was no evidence that Hyalomma marginatum s.l. ticks play a role in the spread of WNV from Africa to Europe.

  • 63.
    Hasan, Badrul
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Faruque, R.
    Drobni, M.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sadique, A.
    Ahmed, K. U.
    Islam, Z.
    Parvez, M. B. H.
    Olsen, Björn
    Alam, M.
    High Prevalence of Antibiotic Resistance in Pathogenic Escherichia coli from Large- and Small-Scale Poultry Farms in Bangladesh2011In: Avian diseases, ISSN 0005-2086, E-ISSN 1938-4351, Vol. 55, no 4, p. 689-692Article in journal (Refereed)
    Abstract [en]

    Antibiotic resistance in avian bacterial pathogens is a common problem in the Bangladesh poultry industry. The aim of the present study was to provide information on the present status of antibiotic resistance patterns in avian pathogenic Escherichia coli in Bangladesh. Of 279 dead or sick poultry of different ages, 101 pathogenic E. coli strains isolated from broilers and layer hens with colibacillosis infections were screened to determine phenotypic expression of antimicrobial resistance against 13 antibiotics used in both veterinary and human medicine in Bangladesh. Of 101 pathogenic E. coli isolates, more than 55% were resistant to at least one or more of the tested compounds, and 36.6% of the isolates showed multiple-drug-resistant phenotypes. The most common resistances observed were against tetracycline (45.5%), trimethoprim-sulphamethoxazole (26.7%), nalidixic acid (25.7%), ampicillin (25.7%), and streptomycin (20.8%). Resistance to ciprofloxacin (12.9%), chlormaphenicol (8.9%), nitrofurantoin (2%), and gentamicin (2%) was also observed, and none of the isolates were resistant to tigecycline as well as extended spectrum beta-lactamase (ESBL) producers. One isolate was resistant to cefuroxime (1%), cefadroxil (1%), and mecillinam (1%) but was not an ESBL producer. Resistance rates, although significant in Bangladeshi isolates, were found to be lower than those reported for avian isolates from the Republic of Korea and clinical, avian, and environmental isolates from Bangladesh. The high level of antibiotic resistance in avian pathogens from Bangladesh is worrisome and indicates that widespread use of antibiotics as feed additives for growth promotion and disease prevention could have negative implications for human and animal health and the environment.

  • 64.
    Hasan, Badrul
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sandegren, Linus
    Melhus, Åsa
    Drobni, Mirva
    Hernandez, Jorge
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Alam, Munirul
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Antimicrobial drug-resistant escherichia coli in wild birds and free-range poultry, Bangladesh2012In: Emerging Infectious Diseases, ISSN 1080-6040, E-ISSN 1080-6059, Vol. 18, no 12, p. 2055-2058Article in journal (Refereed)
    Abstract [en]

    Multidrug resistance was found in 22.7% of Escherichia coli isolates from bird samples in Bangladesh; 30% produced extended-spectrum β-lactamases, including clones of CTX-M genes among wild and domestic birds. Unrestricted use of antimicrobial drugs in feed for domestic birds and the spread of resistance genes to the large bird reservoir in Bangladesh are growing problems.

  • 65. Hasselquist, Dennis
    et al.
    Östman, Örjan
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bensch, Staffan
    Seasonal patterns of occurrence and transmission of the blood parasite Haemoproteus payevksyi in great reed warblers Acrocephalus arundinaceus2007In: Journal of Ornithology = Journal fur Ornithologie, ISSN 0021-8375, E-ISSN 1439-0361, Vol. 148, no 4, p. 401-409Article in journal (Refereed)
  • 66.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Aarts, Lauren
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bususu, Isaya
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Rosengren, Johan
    University of Queensland, Australia‎.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. University of Kansas, USA.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Antimicrobial activity differences in reduced vs. oxidized AvBD3b peptides in mallards (Anas platyrhynchos).2017Conference paper (Other academic)
  • 67.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Aarts, Lauren
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bususu, Isaya
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Rosengren, Johan
    University of Queensland, Australia.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Antimicrobial differences between AvBDs in mallards (Anas platyrhynchos)2018Conference paper (Other academic)
  • 68.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Aarts, Lauren
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bactericidal tests of mallard (Anas plathyrynchos) ß-defensin alleles2017Conference paper (Other academic)
  • 69.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. University of Kansas, USA.
    Tolf, Conny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Aarts, Lauren
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bususu, Isaya
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Rosengren, Johan
    University of Queensland, Australia.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences. Uppsala University, Sweden;Karolinska Institutet, Sweden.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Relation between structure and function of three AvBD3b variants from mallard (Anas platyrhynchos)Manuscript (preprint) (Other academic)
    Abstract [en]

    Defensins are multifunctional antimicrobial peptides expressed in several tissue types and leucocytes as part of the innate immune response against microbes. Based on the three-dimensional structure and disulfide connectivity, vertebrate defensins are subdivided into α-, β-, and θ-defensins. While all three types have been found in mammals, only β-defensins have been identified in birds. Genetic studies have revealed dozens of different avian β-defensin (AvBD) genes in different bird species, as well as allelic variation for different genes. Knowledge of the relation between avian peptide structure features and antimicrobial activity is however limited. In this study, the structure-functional relations of three variants of AvBD3b, a mallard (Anas platyrhynchos) defensin of evolutionary interest, was investigated. Gene alleles encoding two of these peptides, AvBD3b:1 and AvBD3b:2 are common in mallards, whereas AvBD3b:3 occurs rare. These β-defensin peptides were synthesized as linear peptides and subjected to oxidative folding. The three-dimensional structure of AvBD3b:1, including disulfide bond connectivity, was determined using NMR, and those of AvBD3b:2 and AvBD3b:3 respectively, were modelled using AvBD3b:1 as the template. The antimicrobial activities of folded peptides were compared to those of linear peptides. The NMR analysis showed that folded AvBD3b adopts a three-dimensional structure typical for β-defensins, including C-terminal antiparallel β-sheets and disulfide bond organization between six cysteine (C) residues: C6-C34, C13-C28, and C18-C35. Analyses of antimicrobial activity showed that both folded and linear variants of the three peptides inhibited bacterial growth. However, differences in activity were observed, suggesting that folded AvBD3b:3 was the most efficient against both Gram-negative and Gram-positive bacteria. Taken together, these findings provide additional insight into the influence of amino acid sequence variation and three-dimensional structure on the antimicrobial activity of mallard AvBD3b.

  • 70.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. University of Kansas, USA.
    Tolf, Conny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences. Uppsala University, Sweden;Karolinska Institutet, Sweden.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    From genes to function: variation in antimicrobial activity of avian β-defensin peptides from mallardsManuscript (preprint) (Other academic)
    Abstract [en]

    Avian β-defensins are an important class of antimicrobial peptides in birds. These short cationic peptides are directly involved in the clearance of infections by membrane disruption, but can also act as immunomodulators and chemotactic agents recruiting immune cells. Recent genomic studies have shown the presence of several different avian β-defensin (AvBD) genes across the avian phylogeny, but also significant copy number variation and occurrence of pseudogenes. In mallard (Anas platyrhynchos) and other waterfowl AvBD genes are conserved and seem to be maintained by purifying selection. Due to their relatively simple peptide structure and direct mode of action, AvBDs is a potential tractable system to investigate how small differences in the gene sequence translates into differences in immune function. Here, we used genomic information from three different mallard defensin loci (AvBD4, AvBD10 and AvBD13) and synthesized the linear peptides from the most common allele of each locus, plus two rare alleles from AvBD13 locus and measured their antimicrobial activity against Gram-negative (E. coli and S. Typhimurium) and Gram-positive (S. aureus and M. luteus) bacteria. In these assays, AvBD4 showed the most potent antibacterial activity against both Gram-negative and Gram-positive bacteria, with an IC50 value of 0.48 mM against S. Typhimurium. Among AvBD13 peptides, the less frequently observed AvBD13:2 variant, was most potent, with IC50 value against S. aureus approximately 15 times lower than that of the most common AvBD13:1. Interestingly, AvBD10 had no antibacterial effect on the tested bacteria. Thus, antimicrobial function varied substantially among loci, but also within the AvBD13 locus, suggesting a direct link between genetic variation and immune function variation. Interestingly, results from assays with AvBD4 and AvBD13 seem to indicate that a higher positive net charge in peptides is associated with a more potent antibacterial effect.

  • 71.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Wille, Michelle
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Atterby, Clara
    Uppsala University.
    Jarhult, Josef D.
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Univ Kansas, USA.
    A rapid and transient innate immune response to avian influenza infection in mallards2018In: Molecular Immunology, ISSN 0161-5890, E-ISSN 1872-9142, Vol. 95, p. 64-72Article in journal (Refereed)
    Abstract [en]

    The vertebrate innate immune system provides hosts with a rapid, non-specific response to a wide range of invading pathogens. However, the speed and duration of innate responses will be influenced by the co-evolutionary dynamics of specific host-pathogen combinations. Here, we show that low pathogenic avian influenza virus (LPAI) subtype H1N1 elicits a strong but extremely transient innate immune response in its main wildlife reservoir, the mallard (Anas platyrhynchos). Using a series of experimental and methodological improvements over previous studies, we followed the expression of retinoic acid inducible gene 1 (RIG-I) and myxovirus resistance gene (Mx) in mallards semi-naturally infected with low pathogenic H1N1. One day post infection, both RIG-I and Mx were significantly upregulated in all investigated tissues. By two days post infection, the expression of both genes had generally returned to basal levels, and remained so for the remainder of the experiment. This is despite the fact that birds continued to actively shed viral particles throughout the study period. We additionally show that the spleen plays a particularly active role in the innate immune response to LPAI. Waterfowl and avian influenza viruses have a long co-evolutionary history, suggesting that the mallard innate immune response has evolved to provide a minimum effective response to LPAIs such that the viral infection is brought under control while minimising the damaging effects of a sustained immune response.

  • 72.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Wille, Michelle
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Atterby, Clara
    Uppsala University.
    Jarhult, Josef
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Univ Kansas, USA.
    Expression of immune genes RIG-I and Mx in mallard ducks infected with low pathogenic avian influenza (LPAI): A dataset2018In: Data in Brief, E-ISSN 2352-3409, Vol. 18, p. 1562-1566Article in journal (Refereed)
    Abstract [en]

    This article provides data on primer sequences used to amplify the innate immune genes RIG-I and Mx and a set of normalizing reference genes in mallards (Anal platyrhynchos), and shows which reference genes are stable, per tissue, for our experimental settings. Data on the expressional changes of these two genes over a time-course of infection with low pathogenic avian influenza virus (LPAI) are provided. Individual-level data are also presented, including LPAI infection load, and per tissue gene expression of RIG-I and Mx. Gene expression in two outlier individuals is explored in more depth. (C) 2018 The Authors. Published by Elsevier Inc.

  • 73. Hellgren, O.
    et al.
    Wood, M. J.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Hasselquist, D.
    Ottosson, U.
    Stervander, M.
    Bensch, S.
    Circannual variation in blood parasitism in a sub-Saharan migrant passerine bird, the garden warbler2013In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 26, no 5, p. 1047-1059Article in journal (Refereed)
    Abstract [en]

    Knowing the natural dynamics of pathogens in migratory birds is important, for example, to understand the factors that influence the transport of pathogens to and their transmission in new geographical areas, whereas the transmission of other pathogens might be restricted to a specific area. We studied haemosporidian blood parasites of the genera Plasmodium, Haemoproteus and Leucocytozoon in a migratory bird, the garden warbler Sylvia borin. Birds were sampled in spring, summer and early autumn at breeding grounds in Sweden, on migration at Capri, Italy and on arrival and departure from wintering staging areas in West Africa: mapping recoveries of garden warblers ringed in Fennoscandia and Capri showed that these sites are most probably on the migratory flyway of garden warblers breeding at Kvismaren. Overall, haemosporidian prevalence was 39%, involving 24 different parasite lineages. Prevalence varied significantly over the migratory cycle, with relatively high prevalence of blood parasites in the population on breeding grounds and at the onset of autumn migration, followed by marked declines in prevalence during migration both on spring and autumn passage. Importantly, we found that when examining circannual variation in the different lineages, significantly different prevalence profiles emerged both between and within genera. Our results suggest that differences in prevalence profiles are the result of either different parasite transmission strategies or coevolution between the host and the various parasite lineages. When separating parasites into common vs. rare lineages, we found that two peaks in the prevalence of rare parasites occur; on arrival at Swedish breeding grounds, and after the wintering period in Africa. Our results stress the importance of appropriate taxonomic resolution when examining host-parasite interactions, as variation in prevalence both between and within parasite genera can show markedly different patterns.

  • 74. Hellgren, Olof
    et al.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Peréz Tris, Javier
    Szöllösi, Eszter
    Hasselquist, Dennis
    Krizanauskiene, Asta
    Ottosson, Ulf
    Bensch, Staffan
    Detecting shifts of transmission areas in avian blood parasites - a pylogenetic approach2007In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 16, p. 1281-1290Article in journal (Refereed)
  • 75. Helseth, Anders
    et al.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Stervander, Martin
    Migration patterns, population trends and morphometrics of Ruddy Turnstones Arenaria interpres passing Ottenby in south-eastern Sweden2005In: Ornis Svecica, Vol. 15, p. 63-72Article in journal (Refereed)
  • 76.
    Hernandez, Jorge
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University ; Kalmar County Hospital.
    Lindberg, Peter
    University of Göteborg.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Drobni, Mirva
    Uppsala University.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    A novel Salmonella serovar isolated from Peregrine Falcon (Falco peregrinus) nestlings in Sweden: Salmonella enterica enterica serovar Pajala (Salmonella Pajala)2012In: Infection Ecology & Epidemiology, ISSN 2000-8686, E-ISSN 2000-8686, Vol. 2, no 1, article id 7373Article in journal (Refereed)
    Abstract [en]

    A novel Salmonella serovar was isolated from Peregrine falcon (Falco peregrinus) nestlings in northern Sweden in 2006. Three isolates of the same clone was retrieved from three falcon siblings and characterized as Salmonella enterica sub-species enterica: O-phase 13, 23:-: e, n, z 15 and the H-phase was not present. We propose the geographical name Salmonella enterica, sub-species enterica serovar Pajala to this novel Salmonella.

  • 77.
    Hernandez, Jorge
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Prado, Valeria
    Torres, Daniel
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Haemig, Paul
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Enteropathogenic Escherichia coli (EPEC) in Antarctic fur seals Arctocephalus gazella2007In: Polar Biology, ISSN 0722-4060, E-ISSN 1432-2056, Vol. 30, p. 1227-1229Article in journal (Refereed)
  • 78.
    Hernandez, Jorge
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Stedt, Johan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Bonnedahl, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Kalmar County Hospital.
    Molin, Y.
    Drobni, M.
    Calisto-Ulloa, N.
    Gomez-Fuentes, C.
    Astorga-Espana, M. S.
    Gonzalez-Acuna, D.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Blomqvist, Maria
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Human-Associated Extended-Spectrum beta-Lactamase in the Antarctic2012In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 78, no 6, p. 2056-2058Article in journal (Refereed)
    Abstract [en]

    Escherichia coli bacteria with extended-spectrum beta-lactamase (ESBL) type CTX-M resistance were isolated from water samples collected close to research stations in Antarctica. The isolates had bla(CTX-M-1) and bla(CTX-M-15) genotypes and sequence types (ST) indicative of a human-associated origin. This is the first record of ESBL-producing enterobacteria from Antarctica.

  • 79. Hernandez, Jorge
    et al.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bonnedahl, Jonas
    Palmgren, Helena
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Salmonella birds migrating through Sweden2003In: Emerging Infectious Diseases, Vol. 9 (6)Article in journal (Refereed)
  • 80. Hjort, Chrisitian
    et al.
    Andersson, Arne
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Wintering birds on the island of Capri, southwestern Italy2006In: Ornis Svecica, Vol. 16, p. 62-68Article in journal (Refereed)
  • 81.
    Jansson, Désirée S.
    et al.
    National Veterinary Institute.
    Mushtaq, Memoona
    Swedish University of Agricultural Sciences.
    Johansson, Karl-Erik
    Swedish University of Agricultural Sciences.
    Bonnedahl, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Kalmar County Hospital.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Andersson, Dan I.
    Uppsala University.
    Broman, Tina
    FOI – Swedish Defence Research Agency.
    Berg, Charlotte
    Swedish University of Agricultural Sciences.
    Olsen, Björn
    Uppsala University.
    Intestinal spirochaetes (genus Brachyspira) colonise wild birds in the southern Atlantic region and Antarctica2015In: Infection Ecology & Epidemiology, ISSN 2000-8686, E-ISSN 2000-8686, Vol. 5, article id 29296Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: The genus Brachyspira contains well-known enteric pathogens of veterinary significance, suggested agents of colonic disease in humans, and one potentially zoonotic agent. There are recent studies showing that Brachyspira are more widespread in the wildlife community than previously thought. There are no records of this genus in wildlife from the southern Atlantic region and Antarctica. Our aim was therefore, to determine whether intestinal spirochaetes of genus Brachyspira colonise marine and coastal birds in this region.

    METHOD: Faecal samples were collected from marine and coastal birds in the southern Atlantic region, including sub-Antarctic islands and Antarctica, in 2002, 2009, and 2012, with the aim to isolate and characterise zoonotic agents. In total, 205 samples from 11 bird species were selectively cultured for intestinal spirochaetes of genus Brachyspira. To identify isolates to species level, they were subjected to phenotyping, species-specific polymerase chain reactions, sequencing of partial 16S rRNA, NADH oxidase (nox), and tlyA genes, and phylogenetic analysis. Antimicrobial susceptibility tests were performed.

    RESULTS: Fourteen unique strains were obtained from 10 birds of three species: four snowy sheathbills (Chionis albus), three kelp geese (Chloephaga hybrida subsp. malvinarum), and three brown skua (Stercorarius antarcticus subsp. lonnbergi) sampled on the Falkland Islands, Tierra del Fuego in Argentina, South Georgia, South Shetland Islands, and the Antarctic Peninsula. Five Brachyspira strains were closely related to potentially enteropathogenic Brachyspira sp. of chickens: B. intermedia (n=2, from snowy sheathbills), and B. alvinipulli (n=3, from a kelp goose and two snowy sheathbills). Three strains from kelp geese were most similar to the presumed non-pathogenic species 'B. pulli' and B. murdochii, whereas the remaining six strains could not be attributed to currently known species. No isolates related to human strains were found. None of the tested strains showed decreased susceptibility to tiamulin, valnemulin, doxycycline, tylvalosin, lincomycin, or tylosin.

    CONCLUSIONS: This is the first report of intestinal spirochaetes from this region. Despite limitations of current diagnostic methods, our results, together with earlier studies, show that Brachyspira spp., including potentially pathogenic strains, occur globally among free-living avian hosts, and that this genus encompasses a higher degree of biodiversity than previously recognised.

  • 82.
    Johansson, Håkan
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Ellström, Patrik
    Uppsala University.
    Artursson, Karin
    National Veterinary Institute.
    Berg, Charlotte
    Swedish University of Agricultural Sciences.
    Bonnedahl, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Kalmar County Hospital.
    Hansson, Ingrid
    Swedish University of Agricultural Sciences.
    Hernandez, Jorge
    Uppsala University;Kalmar County Hospital.
    Lopez-Martin, Juana
    Univ Concepcion, Chile.
    Medina-Vogel, Gonzalo
    Univ Andres Bello, Chile.
    Moreno, Lucile
    Univ Concepcion, Chile.
    Olsen, Björn
    Uppsala University.
    Engvall, Eva Olsson
    National Veterinary Institute.
    Skarin, Hanna
    National Veterinary Institute.
    Troell, Karin
    National Veterinary Institute.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Agren, Joakim
    National Veterinary Institute.
    Gonzalez-Acuna, Daniel
    Univ Concepcion, Chile.
    Characterization of Campylobacter spp. isolated from wild birds in the Antarctic and Sub-Antarctic2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 11, article id e0206502Article in journal (Refereed)
    Abstract [en]

    A lack of knowledge of naturally occurring pathogens is limiting our ability to use the Antarctic to study the impact human-mediated introduction of infectious microorganisms have on this relatively uncontaminated environment. As no large-scale coordinated effort to remedy this lack of knowledge has taken place, we rely on smaller targeted efforts to both study present microorganisms and monitor the environment for introductions. In one such effort, we isolated Campylobacter species from fecal samples collected from wild birds in the Antarctic Peninsula and the sub-Antarctic island of South Georgia. Indeed, in South Georgia, we found Campylobacter lari and the closely related Campylobacter peloridis, but also distantly related human-associated multilocus sequence types of Campylobacter jejuni. In contrast, in the Antarctic Peninsula, we found C. tart and two closely related species, Campylobacter subantarcticus and Campylobacter volucris, but no signs of human introduction. In fact, our finding of human-associated sequence types of C. jejuni in South Georgia, but not in the Antarctic Peninsula, suggests that efforts to limit the spread of infectious microorganisms to the Antarctic have so far been successful in preventing the introduction of C. jejuni. However, we do not know how it came to South Georgia and whether the same mode of introduction could spread it from there to the Antarctic Peninsula.

  • 83. Jonzén, Niclas
    et al.
    Lindén, A
    Ergon, T
    Knudsen, E
    Vik, J O
    Rubolini, D
    Piacentini, D
    Brinch, C
    Spina, F
    Karlsson, L
    Stervander, Martin
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Andersson, Arne
    Lehikoinen, A
    Edvardsen, E
    Solvang, R
    Stenseth, N C
    Rapid advance of spring arrival dates in long-distance migratory birds2006In: Science, Vol. 312, p. 1959-1961Article in journal (Refereed)
  • 84. Jonzén, Niclas
    et al.
    Piacentini, D
    Andersson, Arne
    Montemaggiori, A
    Stervander, Martin
    Rubolini, D
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Spina, Fernando
    The timing of spring migration in trans-Saharan migrants: a comparison between Ottenby, Sweden, and Capri, Italy2006In: Ornis Svecica, Vol. 16, p. 27-33Article in journal (Refereed)
  • 85. Jonzén, Niclas
    et al.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svensson, Sören
    Trends and cycles in the Swedish Ornithological Society2003In: Ornis Svecica, Vol. 13, p. 107-114Article in journal (Refereed)
  • 86.
    Jourdain, Elsa
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. INRA, France.
    Gunnarsson, Gunnar
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Kristianstad University.
    Wahlgren, John
    Karolinska Institutet ; Swedish Institute for Infectious Disease Control.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Bröjer, Caroline
    National Veterinary Institute ; University of Agricultural Sciences.
    Sahlin, Sofie
    Karolinska Institutet ; Swedish Institute for Infectious Disease Control.
    Svensson, Lovisa
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lundkvist, Åke
    Swedish Institute for Infectious Disease Control.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Influenza Virus in a Natural Host, the Mallard: Experimental Infection Data2010In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, no 1, article id e8935Article in journal (Refereed)
    Abstract [en]

    Wild waterfowl, particularly dabbling ducks such as mallards (Anas platyrhynchos), are considered the main reservoir of low-pathogenic avian influenza viruses (LPAIVs). They carry viruses that may evolve and become highly pathogenic for poultry or zoonotic. Understanding the ecology of LPAIVs in these natural hosts is therefore essential. We assessed the clinical response, viral shedding and antibody production of juvenile mallards after intra-esophageal inoculation of two LPAIV subtypes previously isolated from wild congeners. Six ducks, equipped with data loggers that continually monitored body temperature, heart rate and activity, were successively inoculated with an H7N7 LPAI isolate (day 0), the same H7N7 isolate again (day 21) and an H5N2 LPAI isolate (day 35). After the first H7N7 inoculation, the ducks remained alert with no modification of heart rate or activity. However, body temperature transiently increased in four individuals, suggesting that LPAIV strains may have minor clinical effects on their natural hosts. The excretion patterns observed after both reinoculations differed strongly from those observed after the primary H7N7 inoculation, suggesting that not only homosubtypic but also heterosubtypic immunity exist. Our study suggests that LPAI infection has minor clinically measurable effects on mallards and that mallard ducks are able to mount immunological responses protective against heterologous infections. Because the transmission dynamics of LPAIVs in wild populations is greatly influenced by individual susceptibility and herd immunity, these findings are of high importance. Our study also shows the relevance of using telemetry to monitor disease in animals.

  • 87.
    Jourdain, Elsa
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lundkvist, Ake
    Hubálek, Zdenek
    Sikutová, Silvie
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Karlsson, Malin
    Wahlström, Maria
    Jozan, Martine
    Falk, Kerstin I
    Surveillance for West Nile virus in wild birds from northern Europe.2011In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 11, no 1, p. 77-79Article in journal (Refereed)
    Abstract [en]

    A total of 1935 migratory birds from 104 different species were captured in southeastern Sweden in 2005-2006 and tested for antibodies against West Nile virus (WNV). Overall, 46 birds (2.4%; binomial confidence limits, 1.8-3.2) were positive by blocking-ELISA, but only 2 (0.10%; binomial confidence limits, 0.0-0.4) had antibodies detectable by both blocking-ELISA and WNV neutralization test. ELISA-positive birds included long- and short-distance migrants likely exposed to WNV while wintering in or migrating through areas enzootic for WNV. Exposure to a cross-reactive Flavivirus was suspected for short-distance migrants of the Turdidae family, but no cross-neutralization with tick-borne encephalitis and Usutu viruses was observed.

  • 88.
    Jourdain, Elsa
    et al.
    INRA, France.
    van Riel, Debby
    Erasmus Medical Center, The Netherlands.
    Munster, Vincent J
    National Institutes of Health, USA.
    Kuiken, Thijs
    Erasmus Medical Center, The Netherlands.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Ellström, Patrik
    Uppsala University.
    The pattern of influenza virus attachment varies among wild bird species2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 9, article id e24155Article in journal (Refereed)
    Abstract [en]

    The ability to attach to host cells is one of the main determinants of the host range of influenza A viruses. By using virus histochemistry, we investigate the pattern of virus attachment of both a human and an avian influenza virus in colon and trachea sections from 12 wild bird species. We show that significant variations exist, even between closely related avian species, which suggests that the ability of wild birds to serve as hosts for influenza viruses strongly varies among species. These results will prove valuable to assess the possibilities of interspecies transmission of influenza viruses in natural environments and better understand the ecology of influenza.

  • 89.
    Järhult, Josef D.
    et al.
    Uppsala University.
    Muradrasoli, Shaman
    Swedish University of Agricultural Sciences.
    Wahlgren, John
    Swedish Institute for Infectious Disease Control ; Karolinska Institutet.
    Söderström, Hanna
    Umeå University.
    Orozovic, Goran
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Gunnarsson, Gunnar
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Kristianstad University.
    Bröjer, Caroline
    National Veterinary Institute ; Swedish University of Agricultural Sciences.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Fick, Jerker
    Umeå University.
    Grabic, Roman
    Umeå University ; University of South Bohemia in Ceske Budejovice, Czech Republic.
    Lennerstrand, Johan
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lundkvist, Ake
    Swedish Institute for Infectious Disease Control ; Karolinska Institutet.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Environmental levels of the antiviral oseltamivir induce development of resistance mutation H274Y in influenza A/H1N1 virus in mallards2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 9, article id e24742Article in journal (Refereed)
    Abstract [en]

    Oseltamivir (Tamiflu®) is the most widely used drug against influenza infections and is extensively stockpiled worldwide as part of pandemic preparedness plans. However, resistance is a growing problem and in 2008-2009, seasonal human influenza A/H1N1 virus strains in most parts of the world carried the mutation H274Y in the neuraminidase gene which causes resistance to the drug. The active metabolite of oseltamivir, oseltamivir carboxylate (OC), is poorly degraded in sewage treatment plants and surface water and has been detected in aquatic environments where the natural influenza reservoir, dabbling ducks, can be exposed to the substance. To assess if resistance can develop under these circumstances, we infected mallards with influenza A/H1N1 virus and exposed the birds to 80 ng/L, 1 µg/L and 80 µg/L of OC through their sole water source. By sequencing the neuraminidase gene from fecal samples, we found that H274Y occurred at 1 µg/L of OC and rapidly dominated the viral population at 80 µg/L. IC₅₀ for OC was increased from 2-4 nM in wild-type viruses to 400-700 nM in H274Y mutants as measured by a neuraminidase inhibition assay. This is consistent with the decrease in sensitivity to OC that has been noted among human clinical isolates carrying H274Y. Environmental OC levels have been measured to 58-293 ng/L during seasonal outbreaks and are expected to reach µg/L-levels during pandemics. Thus, resistance could be induced in influenza viruses circulating among wild ducks. As influenza viruses can cross species barriers, oseltamivir resistance could spread to human-adapted strains with pandemic potential disabling oseltamivir, a cornerstone in pandemic preparedness planning. We propose surveillance in wild birds as a measure to understand the resistance situation in nature and to monitor it over time. Strategies to lower environmental levels of OC include improved sewage treatment and, more importantly, a prudent use of antivirals.

  • 90.
    Kanagarajan, Selvaraju
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Tolf, Conny
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lundgren, Anneli
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Brodelius, Peter E.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Transient Expression of Hemagglutinin Antigen from Low Pathogenic Avian Influenza A (H7N7) in Nicotiana benthamiana2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 3, article id e33010Article in journal (Refereed)
    Abstract [en]

    The influenza A virus is of global concern for the poultry industry, especially the H5 and H7 subtypes as they have the potential to become highly pathogenic for poultry. In this study, the hemagglutinin (HA) of a low pathogenic avian influenza virus of the H7N7 subtype isolated from a Swedish mallard Anas platyrhynchos was sequenced, characterized and transiently expressed in Nicotiana benthamiana. Recently, plant expression systems have gained interest as an alternative for the production of vaccine antigens. To examine the possibility of expressing the HA protein in N. benthamiana, a cDNA fragment encoding the HA gene was synthesized de novo, modified with a Kozak sequence, a PR1a signal peptide, a C-terminal hexahistidine (6xHis) tag, and an endoplasmic retention signal (SEKDEL). The construct was cloned into a Cowpea mosaic virus (CPMV)-based vector (pEAQ-HT) and the resulting pEAQ-HT-HA plasmid, along with a vector (pJL3:p19) containing the viral gene-silencing suppressor p19 from Tomato bushy stunt virus, was agro-infiltrated into N. benthamiana. The highest gene expression of recombinant plant-produced, uncleaved HA (rHA0), as measured by quantitative real-time PCR was detected at 6 days post infiltration (dpi). Guided by the gene expression profile, rHA0 protein was extracted at 6 dpi and subsequently purified utilizing the 6xHis tag and immobilized metal ion adsorption chromatography. The yield was 0.2 g purified protein per kg fresh weight of leaves. Further molecular characterizations showed that the purified rHA0 protein was N-glycosylated and its identity confirmed by liquid chromatography-tandem mass spectrometry. In addition, the purified rHA0 exhibited hemagglutination and hemagglutination inhibition activity indicating that the rHA0 shares structural and functional properties with native HA protein of H7 influenza virus. Our results indicate that rHA0 maintained its native antigenicity and specificity, providing a good source of vaccine antigen to induce immune response in poultry species.

  • 91. Keller, Judith I
    et al.
    Shriver, W Gregory
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Griekspoor, Petra
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Prevalence of Campylobacter in wild birds of the mid-Atlantic region, USA.2011In: Journal of Wildlife Diseases, ISSN 0090-3558, E-ISSN 1943-3700, Vol. 47, no 3, p. 750-754Article in journal (Refereed)
    Abstract [en]

    We evaluated the occurrence of three Campylobacter species--C. jejuni, C. coli, and C. lari--from 333 wild bird fecal samples collected at Tri-State Bird Rescue and Research in Newark, Delaware, in 2008. Using multiplex polymerase chain reaction, we detected C. jejuni from six avian families with an overall prevalence rate of 7.2%. We did not detect any other Campylobacter species. Campylobacter jejuni prevalence ranged widely between different avian families with crows (Corvidae) and gulls (Laridae) having the highest prevalence rates (23% and 25%, respectively).

  • 92.
    Kleyheeg, Erik
    et al.
    Max Planck Inst Ornithol, Germany.
    Fiedler, Wolfgang
    Max Planck Inst Ornithol, Germany.
    Safi, Kamran
    Max Planck Inst Ornithol, Germany.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Wikelski, Martin
    Max Planck Inst Ornithol, Germany.
    van Toor, Mariëlle L.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    A Comprehensive Model for the Quantitative Estimation of Seed Dispersal by Migratory Mallards2019In: Frontiers in Ecology and Evolution, E-ISSN 2296-701X, Vol. 7, p. 1-14, article id 40Article in journal (Refereed)
    Abstract [en]

    Long-distance seed dispersal is an important ecosystem service provided by migratory animals. Plants inhabiting discrete habitats, like lakes and wetlands, experience dispersal limitation, and rely heavily on zoochory for their spatial population dynamics. Granivorous waterbirds may disperse viable seeds of wetland plants over long distances during migration. The limited knowledge of waterbird migration has long hampered the evaluation of the importance of waterbirds in seed dispersal, requiring key metrics such as realistic dispersal distances. Using recent GPS tracking of mallards during spring migration, we built a mechanistic seed dispersal model to estimate realistic dispersal distances. Mallards are abundant, partially migratory ducks known to consume seeds of >300 European plant species. Based on the tracking data, we informed a mallard migration simulator to obtain a probabilistic spring migration model for the mallard population wintering at Lake Constance in Southern Germany. We combined the spring migration model with seed retention curves to develop seed dispersal kernels. We also assessed the effects of pre-migratory fasting and the availability of suitable deposition habitats for aquatic and wetland plants. Our results show that mallards at Lake Constance can disperse seeds in the northeastern direction over median distances of 293 and 413 km for seeds with short and long retention times, respectively, assuming a departure immediately after foraging. Pre-migratory fasting strongly affected the dispersal potential, with only 1-7% of ingested seeds left for dispersal after fasting for 12 h. Availability of a suitable deposition habitat was generally <5% along the migratory flyway. The high probability of seed deposition in a freshwater habitat during the first stopover, after the mallards completed the first migratory flight, makes successful dispersal most likely to happen at 204-322 km from Lake Constance. We concluded that the directed long-distance dispersal of plant seeds, realized by mallards on spring migration, may contribute significantly to large scale spatial plant population dynamics, including range expansion in response to shifting temperature and rainfall patterns under global warming. Our dispersal model is the first to incorporate detailed behavior of migratory waterbirds and can be readily adjusted to include other vector species when tracking data are available.

  • 93.
    Kraus, Robert H. S.
    et al.
    Wageningen University, The Netherlands.
    van Hooft, Pim
    Wageningen University, The Netherlands.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Ydenberg, Ronald C.
    Wageningen University, The Netherlands ; Simon Fraser University, Canada.
    Prins, Herbert H. T.
    Wageningen University, The Netherlands.
    Avian influenza surveillance with FTA cards: field methods, biosafety, and transportation issues solved2011In: Journal of Visualized Experiments, ISSN 1940-087X, E-ISSN 1940-087X, no 54, article id 2832Article in journal (Refereed)
    Abstract [en]

    Avian Influenza Viruses (AIVs) infect many mammals, including humans(1). These AIVs are diverse in their natural hosts, harboring almost all possible viral subtypes(2). Human pandemics of flu originally stem from AIVs(3). Many fatal human cases during the H5N1 outbreaks in recent years were reported. Lately, a new AIV related strain swept through the human population, causing the 'swine flu epidemic'(4). Although human trading and transportation activity seems to be responsible for the spread of highly pathogenic strains(5), dispersal can also partly be attributed to wild birds(6, 7). However, the actual reservoir of all AIV strains is wild birds. In reaction to this and in face of severe commercial losses in the poultry industry, large surveillance programs have been implemented globally to collect information on the ecology of AIVs, and to install early warning systems to detect certain highly pathogenic strains(8-12). Traditional virological methods require viruses to be intact and cultivated before analysis. This necessitates strict cold chains with deep freezers and heavy biosafety procedures to be in place during transport. Long-term surveillance is therefore usually restricted to a few field stations close to well equipped laboratories. Remote areas cannot be sampled unless logistically cumbersome procedures are implemented. These problems have been recognised(13, 14) and the use of alternative storage and transport strategies investigated (alcohols or guanidine)(15-17). Recently, Kraus et al.(18) introduced a method to collect, store and transport AIV samples, based on a special filter paper. FTA cards(19) preserve RNA on a dry storage basis(20) and render pathogens inactive upon contact(21). This study showed that FTA cards can be used to detect AIV RNA in reverse-transcription PCR and that the resulting cDNA could be sequenced and virus genes and determined. In the study of Kraus et al.(18) a laboratory isolate of AIV was used, and samples were handled individually. In the extension presented here, faecal samples from wild birds from the duck trap at the Ottenby Bird Observatory (SE Sweden) were tested directly to illustrate the usefulness of the methods under field conditions. Catching of ducks and sample collection by cloacal swabs is demonstrated. The current protocol includes up-scaling of the work flow from single tube handling to a 96-well design. Although less sensitive than the traditional methods, the method of FTA cards provides an excellent supplement to large surveillance schemes. It allows collection and analysis of samples from anywhere in the world, without the need to maintaining a cool chain or safety regulations with respect to shipping of hazardous reagents, such as alcohol or guanidine.

  • 94. Krone, O
    et al.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Valkiunas, G
    Lessow, O
    Müller, K
    Iezhova, T A
    Fickel, J
    Bensch, Staffan
    Haemosporidian blood parasites in European birds of prey and owls2008In: Journal of Parasitology, ISSN 0022-3395, E-ISSN 1937-2345, Vol. 94, no 3, p. 709-715Article in journal (Refereed)
    Abstract [en]

    Avian blood parasites have been intensively studied using morphological methods with limited information on their host specificity and species taxonomic status. Now the analysis of gene sequences, especially the mitochondrial cytochrome b gene of the avian haemosporidian species of Haemoproteus, Plasmodium, and Leucocytozoon, offers a new tool to review the parasite specificity and status. By comparing morphological and genetic techniques, we observed nearly the same overall prevalence of haemosporidian parasites by microscopy (19.8%) and polymerase chain reaction (PCR) (21.8%) analyses. However, in contrast to the single valid Leucocytozoon species (L. toddi) in the Falconiformes we detected 4 clearly distinctive strains by PCR screening. In the Strigiformes, where the only valid Leucocytozoon species is L. danilewskyi, we detected 3 genetically different strains of Leucocytozoon spp. Two strains of Haemoproteus spp. were detected in the birds of prey and owls examined, whereas the strain found in the tawny owl belonged to the morphospecies Haemoproteus noctuae. Three Plasmodium spp. strains that had already been found in Passeriformes were also detected in the birds of prey and owls examined here, supporting previous findings indicating a broad and nonspecific host spectrum bridging different bird orders.

  • 95.
    Lang, Andrew S.
    et al.
    Mem Univ Newfoundland, Canada.
    Lebarbenchon, Camille
    Univ Reunion, Reunion.
    Ramey, Andrew M.
    US Geol Survey, USA.
    Robertson, Gregory J.
    Environm Canada, Canada.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Wille, Michelle
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Assessing the Role of Seabirds in the Ecology of Influenza A Viruses2016In: Avian diseases, ISSN 0005-2086, E-ISSN 1938-4351, Vol. 60, no 1, p. 378-386Article in journal (Refereed)
    Abstract [en]

    Wild waterbirds, specifically waterfowl, gulls, and shorebirds, are recognized as the primordial reservoir of influenza A viruses (IAVs). However, the role of seabirds, an abundant, diverse, and globally distributed group of birds, in the perpetuation and transmission of IAVs is less clear. Here we summarize published and publicly available data for influenza viruses in seabirds, which for the purposes of this study are defined as birds that exhibit a largely or exclusively pelagic lifestyle and exclude waterfowl, gulls, and shorebirds, and we review this collective dataset to assess the role of seabirds in the influenza A ecology. Since 1961, more than 40,000 samples have been collected worldwide from the seabirds considered here and screened, using a variety of techniques, for evidence of active or past IAV infection. From these data, the overall prevalence of active infection has been estimated to be very low; however, serological data provide evidence that some seabird species are more frequently exposed to IAVs. Sequence data for viruses from seabirds are limited, except for murres (common murre, Uria aalge, and thick-billed murre, Uria lomvia; family Alcidae) for which there are full or partial genome sequences available for more than 80 viruses. Characterization of these viruses suggests that murres are infected with Group 1 hemagglutinin subtype viruses more frequently as compared to Group 2 and also indicates that these northern, circumpolar birds are frequently infected by intercontinental reassortant viruses. Greater temporal and spatial sampling and characterization of additional viruses are required to better understand the role of seabirds in global IAV dynamics.

  • 96.
    Latorre-Margalef, Neus
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Univ Georgia, USA.
    Avril, Alexis
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Tolf, Conny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olsen, Björn
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    How Does Sampling Methodology Influence Molecular Detection and Isolation Success in Influenza A Virus Field Studies?2016In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 82, no 4, p. 1147-1153Article in journal (Refereed)
    Abstract [en]

    Wild waterfowl are important reservoir hosts for influenza A virus (IAV) and a potential source of spillover infections in other hosts, including poultry and swine. The emergence of highly pathogenic avian influenza (HPAI) viruses, such as H5N1 and H5N8, and subsequent spread along migratory flyways prompted the initiation of several programs in Europe, North America, and Africa to monitor circulation of HPAI and low-pathogenicity precursor viruses (low-pathogenicity avian influenza [LPAI] viruses). Given the costs of maintaining such programs, it is essential to establish best practice for field methodologies to provide robust data for epidemiological interpretation. Here, we use long-term surveillance data from a single site to evaluate the influence of a number of parameters on virus detection and isolation of LPAI viruses. A total of 26,586 samples (oropharyngeal, fecal, and cloacal) collected from wild mallards were screened by real-time PCR, and positive samples were subjected to isolation in embryonated chicken eggs. The LPAI virus detection rate was influenced by the sample type: cloacal/fecal samples showed a consistently higher detection rate and lower cycle threshold (Ct) value than oropharyngeal samples. Molecular detection was more sensitive than isolation, and virus isolation success was proportional to the number of RNA copies in the sample. Interestingly, for a given Ct value, the isolation success was lower in samples from adult birds than in those from juveniles. Comparing the results of specific real-time reverse transcriptase (RRT)-PCRs and of isolation, it was clear that coinfections were common in the investigated birds. The effects of sample type and detection methods warrant some caution in interpretation of the surveillance data.

  • 97.
    Latorre-Margalef, Neus
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Grosbois, Vladimir
    International Research Center in Agriculture for Development, France.
    Wahlgren, John
    Karolinska Institutet.
    Munster, Vincent J.
    Erasmus Medical Center, The Netherlands ; National Institutes of Health, USA.
    Tolf, Conny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Fouchier, Ron A. M.
    Erasmus Medical Center, The Netherlands.
    Osterhaus, Albert D. M. E.
    Erasmus Medical Center, The Netherlands.
    Olsen, Björn
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Heterosubtypic Immunity to Influenza A Virus Infections in Mallards May Explain Existence of Multiple Virus Subtypes2013In: PLoS Pathogens, ISSN 1553-7366, E-ISSN 1553-7374, Vol. 9, no 6, article id e1003443Article in journal (Refereed)
    Abstract [en]

    Wild birds, particularly duck species, are the main reservoir of influenza A virus (IAV) in nature. However, knowledge of IAV infection dynamics in the wild bird reservoir, and the development of immune responses, are essentially absent. Importantly, a detailed understanding of how subtype diversity is generated and maintained is lacking. To address this, 18,679 samples from 7728 Mallard ducks captured between 2002 and 2009 at a single stopover site in Sweden were screened for IAV infections, and the resulting 1081 virus isolates were analyzed for patterns of immunity. We found support for development of homosubtypic hemagglutinin (HA) immunity during the peak of IAV infections in the fall. Moreover, re-infections with the same HA subtype and related prevalent HA subtypes were uncommon, suggesting the development of natural homosubtypic and heterosubtypic immunity (p-value = 0.02). Heterosubtypic immunity followed phylogenetic relatedness of HA subtypes, both at the level of HA clades (p-value = 0.04) and the level of HA groups (p-value = 0.05). In contrast, infection patterns did not support specific immunity for neuraminidase (NA) subtypes. For the H1 and H3 Clades, heterosubtypic immunity showed a clear temporal pattern and we estimated within-clade immunity to last at least 30 days. The strength and duration of heterosubtypic immunity has important implications for transmission dynamics of IAV in the natural reservoir, where immune escape and disruptive selection may increase HA antigenic variation and explain IAV subtype diversity.

  • 98.
    Latorre-Margalef, Neus
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Gunnarsson, Gunnar
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Munster, V J
    Fouchier, R A M
    Osterhaus, A D M E
    Elmberg, J
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Wallensten, Anders
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Fransson, T
    Brudin, Lars
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Does Influenza A affect body condition of wild mallard ducks, or vice versa? A reply to Flint & Franson2009In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 276, no 1666, p. 2347-2349Article in journal (Refereed)
  • 99.
    Latorre-Margalef, Neus
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Gunnarsson, Gunnar
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Munster, V.J.
    Fouchier, R.A.M.
    Osterhaus, A.D.M.E.
    Elmberg, Johan
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Wallensten, Anders
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Haemig, Paul D.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Fransson, Thord
    Brudin, Lars
    University of Kalmar, School of Pure and Applied Natural Sciences. Kalmar County Hospital.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Effects of influenza A virus infection on migrating mallard ducks2009In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 276, no 1659, p. 1029-1036Article in journal (Refereed)
    Abstract [en]

    The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002-2007, we collected faecal samples (n = 10 918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales.

  • 100.
    Latorre-Margalef, Neus
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Univ Georgia, Dept Populat Hlth, Coll Vet Med, Southeastern Cooperat Wildlife Dis Study, Athens, GA 30602 USA.
    Tolf, Conny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Grosbois, Vladimir
    Int Res Ctr Agr Dev CIRAD UPR AGIRs, Anim & Integrate Risk Management, F-34398 Montpellier, France.
    Avril, Alexis
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bengtsson, Daniel
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Wille, Michelle
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Osterhaus, Albert D M E
    Erasmus MC, Dept Virol, Rotterdam, Netherlands.
    Fouchier, Ron A M
    Erasmus MC, Dept Virol, Rotterdam, Netherlands.
    Olsen, Björn
    Uppsala Univ.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Long-term variation in influenza A virus prevalence and subtype diversity in migratory mallards in northern Europe.2014In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, no 1781, p. Article ID: UNSP 20140098-Article in journal (Refereed)
    Abstract [en]

    Data on long-term circulation of pathogens in wildlife populations are seldom collected, and hence understanding of spatial-temporal variation in prevalence and genotypes is limited. Here, we analysed a long-term surveillance series on influenza A virus (IAV) in mallards collected at an important migratory stopover site from 2002 to 2010, and characterized seasonal dynamics in virus prevalence and subtype diversity. Prevalence dynamics were influenced by year, but retained a common pattern for all years whereby prevalence was low in spring and summer, but increased in early autumn with a first peak in August, and a second more pronounced peak during October-November. A total of 74 haemagglutinin (HA)/neuraminidase (NA) combinations were isolated, including all NA and most HA (H1-H12) subtypes. The most common subtype combinations were H4N6, H1N1, H2N3, H5N2, H6N2 and H11N9, and showed a clear linkage between specific HA and NA subtypes. Furthermore, there was a temporal structuring of subtypes within seasons based on HA phylogenetic relatedness. Dissimilar HA subtypes tended to have different temporal occurrence within seasons, where the subtypes that dominated in early autumn were rare in late autumn, and vice versa. This suggests that build-up of herd immunity affected IAV dynamics in this system.

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