| 1. |
- Humphries, Grant R. W., et al.
(författare)
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BRIDGING THE GAP FROM STUDENT TO SENIOR SCIENTIST : RECOMMENDATIONS FOR ENGAGING EARLY-CAREER SCIENTISTS IN PROFESSIONAL BIOLOGICAL SOCIETIES
- 2016
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Ingår i: Marine Ornithology. - : AFRICAN SEABIRD GROUP. - 1018-3337 .- 2074-1235. ; 44:2, s. 157-166
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Tidskriftsartikel (refereegranskat)abstract
- Despite their long-standing and central role in the dissemination, promotion and defense of science. scientific societies currently face a unique combination of economic, social and technological changes. As a result, one of the most pressing challenges facing many societies is declining membership due to reduced recruitment and a failure to retain members, particularly early-career scientists (ECSs). To ensure that professional biological societies retain long-term viability and relevance, the recruitment and retention of ECSs needs to be a main priority. Here we propose a series of recommendations that we, a group of ECSs, believe will help professional societies better integrate and retain ECSs. We discuss each recommendation and detail its implementation using examples from our personal experiences in the global seabird research and management communities and from our collective experience as members of several professional societies. We believe these recommendations will not only help recruit and retain ECSs as society members, but will also directly benefit the organizations themselves.
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| 2. |
- Borg, O., et al.
(författare)
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Expansion of spatial and host range of Puumala virus in Sweden : an increasing threat for humans?
- 2017
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Ingår i: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 145:8, s. 1642-1648
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Tidskriftsartikel (refereegranskat)abstract
- Hantaviruses are globally distributed and cause severe human disease. Puumala hantavirus (PUUV) is the most common species in Northern Europe, and the only hantavirus confirmed to circulate in Sweden, restricted to the northern regions of the country. In this study, we aimed to further add to the natural ecology of PUUV in Sweden by investigating prevalence, and spatial and host species infection patterns. Specifically, we wanted to ascertain whether PUUV was present in the natural reservoir, the bank vole (Myodes glareolus) further south than Dalälven river, in south-central Sweden, and whether PUUV can be detected in other rodent species in addition to the natural reservoir. In total, 559 animals were collected at Grimsö (59°43'N; 15°28'E), Sala (59°55'N; 16°36'E) and Bogesund (59°24'N; 18°14'E) in south-central Sweden between May 2013 and November 2014. PUUV ELISA-reactive antibodies were found both in 2013 (22/295) and in 2014 (18/264), and nine samples were confirmed as PUUV-specific by focus reduction neutralization test. Most of the PUUV-specific samples were from the natural host, the bank vole, but also from other rodent hosts, indicating viral spill-over. Finally, we showed that PUUV is present in more highly populated central Sweden.
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| 3. |
- Chang, Wei-Shan, et al.
(författare)
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Novel hepatitis D-like agents in vertebrates and invertebrates
- 2019
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Ingår i: Virus Evolution. - : OXFORD UNIV PRESS. - 2057-1577. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis delta virus (HDV) is the smallest known RNA virus, encoding a single protein. Until recently, HDV had only been identified in humans, where it is strongly associated with co-infection with hepatitis B virus (HBV). However, the recent discovery of HDV-like viruses in metagenomic samples from birds and snakes suggests that this virus has a far longer evolutionary history. Herein, using additional meta-transcriptomic data, we show that highly divergent HDV-like viruses are also present in fish, amphibians, and invertebrates, with PCR and Sanger sequencing confirming the presence of the invertebrate HDV-like viruses. Notably, the novel viruses identified here share genomic features characteristic of HDV, such as a circular genome of only approximately 1.7 kb in length, and self-complementary, unbranched rod-like structures. Coiled-coil domains, leucine zippers, conserved residues with essential biological functions, and isoelectronic points similar to those in the human hepatitis delta virus antigens (HDAgs) were also identified in the putative non-human viruses. Importantly, none of these novel HDV-like viruses were associated with hepadnavirus infection, supporting the idea that the HDV-HBV association may be specific to humans. Collectively, these data not only broaden our understanding of the diversity and host range of HDV, but also shed light on its origin and evolutionary history.
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| 4. |
- Chapman, Joanne R., et al.
(författare)
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A Panel of Stably Expressed Reference Genes for Real-Time qPCR Gene Expression Studies of Mallards (Anas platyrhynchos)
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- Determining which reference genes have the highest stability, and are therefore appropriate for normalising data, is a crucial step in the design of real-time quantitative PCR (qPCR) gene expression studies. This is particularly warranted in non-model and ecologically important species for which appropriate reference genes are lacking, such as the mallard-a key reservoir of many diseases with relevance for human and livestock health. Previous studies assessing gene expression changes as a consequence of infection in mallards have nearly universally used beta-actin and/or GAPDH as reference genes without confirming their suitability as normalisers. The use of reference genes at random, without regard for stability of expression across treatment groups, can result in erroneous interpretation of data. Here, eleven putative reference genes for use in gene expression studies of the mallard were evaluated, across six different tissues, using a low pathogenic avian influenza A virus infection model. Tissue type influenced the selection of reference genes, whereby different genes were stable in blood, spleen, lung, gastrointestinal tract and colon. beta-actin and GAPDH generally displayed low stability and are therefore inappropriate reference genes in many cases. The use of different algorithms (GeNorm and NormFinder) affected stability rankings, but for both algorithms it was possible to find a combination of two stable reference genes with which to normalise qPCR data in mallards. These results highlight the importance of validating the choice of normalising reference genes before conducting gene expression studies in ducks. The fact that nearly all previous studies of the influence of pathogen infection on mallard gene expression have used a single, non-validated reference gene is problematic. The toolkit of putative reference genes provided here offers a solid foundation for future studies of gene expression in mallards and other waterfowl.
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| 5. |
- Gillman, Anna, et al.
(författare)
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Influenza A(H7N9) Virus Acquires Resistance-Related Neuraminidase I222T Substitution When Infected Mallards Are Exposed to Low Levels of Oseltamivir in Water
- 2015
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Ingår i: Antimicrobial Agents and Chemotherapy. - : American Society for Biochemistry and Molecular Biology. - 0066-4804 .- 1098-6596. ; 59:9, s. 5196-5202
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Tidskriftsartikel (refereegranskat)abstract
- Influenza A virus (IAV) has its natural reservoir in wild waterfowl, and new human IAVs often contain gene segments originating from avian IAVs. Treatment options for severe human influenza are principally restricted to neuraminidase inhibitors (NAIs), among which oseltamivir is stockpiled in preparedness for influenza pandemics. There is evolutionary pressure in the environment for resistance development to oseltamivir in avian IAVs, as the active metabolite oseltamivir carboxylate (OC) passes largely undegraded through sewage treatment to river water where waterfowl reside. In an in vivo mallard (Anas platyrhynchos) model, we tested if low-pathogenic avian influenza A(H7N9) virus might become resistant if the host was exposed to low levels of OC. Ducks were experimentally infected, and OC was added to their water, after which infection and transmission were maintained by successive introductions of uninfected birds. Daily fecal samples were tested for IAV excretion, genotype, and phenotype. Following mallard exposure to 2.5 mu g/liter OC, the resistance-related neuraminidase (NA) I222T substitution, was detected within 2 days during the first passage and was found in all viruses sequenced from subsequently introduced ducks. The substitution generated 8-fold and 2.4-fold increases in the 50% inhibitory concentration (IC50) for OC (P < 0.001) and zanamivir (P = 0.016), respectively. We conclude that OC exposure of IAV hosts, in the same concentration magnitude as found in the environment, may result in amino acid substitutions, leading to changed antiviral sensitivity in an IAV subtype that can be highly pathogenic to humans. Prudent use of oseltamivir and resistance surveillance of IAVs in wild birds are warranted.
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| 6. |
- Gillman, Anna, et al.
(författare)
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Oseltamivir Resistance in Influenza A(H6N2) Caused by an R292K Substitution in Neuraminidase Is Not Maintained in Mallards without Drug Pressure
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Background Wild waterfowl is the natural reservoir of influenza A virus (IAV); hosted viruses are very variable and provide a source for genetic segments which can reassort with poultry or mammalian adapted IAVs to generate novel species crossing viruses. Additionally, wild waterfowl act as a reservoir for highly pathogenic IAVs. Exposure of wild birds to the antiviral drug oseltamivir may occur in the environment as its active metabolite can be released from sewage treatment plants to river water. Resistance to oseltamivir, or to other neuraminidase inhibitors (NAIs), in IAVs of wild waterfowl has not been extensively studied. Aim and Methods In a previous in vivo Mallard experiment, an influenza A(H6N2) virus developed oseltamivir resistance by the R292K substitution in the neuraminidase (NA), when the birds were exposed to oseltamivir. In this study we tested if the resistance could be maintained in Mallards without drug exposure. Three variants of resistant H6N2/R292K virus were each propagated during 17 days in five successive pairs of naive Mallards, while oseltamivir exposure was decreased and removed. Daily fecal samples were analyzed for viral presence, genotype and phenotype. Results and Conclusion Within three days without drug exposure no resistant viruses could be detected by NA sequencing, which was confirmed by functional NAI sensitivity testing. We conclude that this resistant N2 virus could not compete in fitness with wild type subpopulations without oseltamivir drug pressure, and thus has no potential to circulate among wild birds. The results of this study contrast to previous observations of drug induced resistance in an avian H1N1 virus, which was maintained also without drug exposure in Mallards. Experimental observations on persistence of NAI resistance in avian IAVs resemble NAI resistance seen in human IAVs, in which resistant N2 subtypes do not circulate, while N1 subtypes with permissive mutations can circulate without drug pressure. We speculate that the phylogenetic group N1 NAs may easier compensate for NAI resistance than group N2 NAs, though further studies are needed to confirm such conclusions.
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| 7. |
- Helin, Anu S., et al.
(författare)
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A rapid and transient innate immune response to avian influenza infection in mallards
- 2018
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 95, s. 64-72
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Helin, Anu S., et al.
(författare)
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Expression of immune genes RIG-I and Mx in mallard ducks infected with low pathogenic avian influenza (LPAI) : A dataset
- 2018
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Ingår i: Data in Brief. - : Elsevier. - 2352-3409. ; 18, s. 1562-1566
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 9. |
- Isaksson, Jenny, et al.
(författare)
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Chlamydiaceae-like bacterium, but no Chlamydia psittaci, in sea birds from Antarctica
- 2015
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Ingår i: Polar Biology. - : Springer Science and Business Media LLC. - 0722-4060 .- 1432-2056. ; 38:11, s. 1931-1936
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Tidskriftsartikel (refereegranskat)abstract
- Within the growing order of Chlamydiales, there are a number of pathogens. One is Chlamydia psittaci, a zoonotic pathogen, with birds as natural hosts that may be transmitted to humans and cause severe respiratory disease, psittacosis. The prevalence of this pathogen in Antarctic birds is almost unknown as well as the ramifications of its potential spread in na < ve bird populations. To investigate the prevalence of chlamydia organisms, cloacal and fecal samples were collected from 264 penguins and 263 seabirds on the Antarctic Peninsula and in Southern Chile. No C. psittaci could be detected by 23S rRNA real-time PCR. However, DNA sequencing of the 16S rRNA 298-bp signature sequence revealed a Chlamydiaceae-like bacterium previously found in seabirds from the subarctic zone, demonstrating that this not yet fully characterized bacterium is widespread. In conclusion, the prevalence of C. psittaci among wild birds on the Antarctic Peninsula seems to be low, but other types of chlamydial organisms are common. Further studies are required to taxonomically define and finally understand the role of these non-classified Chlamydiae.
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| 10. |
- Lang, Andrew S., et al.
(författare)
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Assessing the Role of Seabirds in the Ecology of Influenza A Viruses
- 2016
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Ingår i: Avian diseases. - 0005-2086 .- 1938-4351. ; 60:1, s. 378-386
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 11. |
- 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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| 12. |
- Nykvist, Marie, et al.
(författare)
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In vivo mallard experiments indicate that zanamivir has less potential for environmental influenza A virus resistance development than oseltamivir
- 2017
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Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 98, s. 2937-2949
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Tidskriftsartikel (refereegranskat)abstract
- Neuraminidase inhibitors are a cornerstone of influenza pandemic preparedness before vaccines can be mass-produced and thus a neuraminidase inhibitor-resistant pandemic is a serious threat to public health. Earlier work has demonstrated the potential for development and persistence of oseltamivir resistance in influenza A viruses exposed to environmentally relevant water concentrations of the drug when infecting mallards, the natural influenza reservoir that serves as the genetic base for human pandemics. As zanamivir is the major second-line neuraminidase inhibitor treatment, this study aimed to assess the potential for development and persistence of zanamivir resistance in an in vivo mallard model; especially important as zanamivir will probably be increasingly used. Our results indicate less potential for development and persistence of resistance due to zanamivir than oseltamivir in an environmental setting. This conclusion is based on: (1) the lower increase in zanamivir IC50 conferred by the mutations caused by zanamivir exposure (2-17-fold); (2) the higher zanamivir water concentration needed to induce resistance (at least 10 µg l-1); (3) the lack of zanamivir resistance persistence without drug pressure; and (4) the multiple resistance-related substitutions seen during zanamivir exposure (V116A, A138V, R152K, T157I and D199G) suggesting lack of one straight-forward evolutionary path to resistance. Our study also adds further evidence regarding the stability of the oseltamivir-induced substitution H275Y without drug pressure, and demonstrates the ability of a H275Y-carrying virus to acquire secondary mutations, further boosting oseltamivir resistance when exposed to zanamivir. Similar studies using influenza A viruses of the N2-phylogenetic group of neuraminidases are recommended.
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| 13. |
- van Dijk, Jacintha G. B., et al.
(författare)
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Host and virus ecology as determinants of influenza A virus transmission in wild birds
- 2018
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Ingår i: Current Opinion in Virology. - : Elsevier. - 1879-6257 .- 1879-6265. ; 28, s. 26-36
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Tidskriftsartikel (refereegranskat)abstract
- Low pathogenic influenza A virus (LPIAV) prevalence and subtype distribution differs between and across bird taxa. A crucial factor in the epidemiology of these viruses and virus subtypes is the ability to transmit between and within different host taxa and individuals. Successful viral transmission depends on availability of susceptible hosts and exposure of host to virus. Exposure to viruses and susceptibility to virus infection and/or disease are shaped by both host and virus traits. In this review we have identified key host and virus traits that can affect LPIAV transmission, both in terms of exposure and susceptibility. Furthermore we highlight current challenges in assessment of these traits and identify methodological considerations for future studies.
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| 14. |
- Wille, Michelle, et al.
(författare)
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A Pelagic Outbreak Of Avian Cholera In North American Gulls : Scavenging As A Primary Mechanism For Transmission?
- 2016
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Ingår i: Journal of Wildlife Diseases. - : Wildlife Disease Association. - 0090-3558 .- 1943-3700. ; 52:4, s. 793-802
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Tidskriftsartikel (refereegranskat)abstract
- Avian cholera, caused by the bacterium Pasteurella multocida, is an endemic disease globally, often causing annual epizootics in North American wild bird populations with thousands of mortalities. From December 2006 to March 2007, an avian cholera outbreak caused mortality in marine birds off the coast of Atlantic Canada, largely centered 300-400 km off the coast of the island of Newfoundland. Scavenging gulls (Larus spp.) were the primary species detected; however, mortality was also identified in Black-legged Kittiwakes (Rissa tridactyla) and one Common Raven (Corvus corax), a nonmarine species. The most common gross necropsy findings in the birds with confirmed avian cholera were acute fibrinous and necrotizing lesions affecting the spleen, air sacs, and pericardium, and nonspecific hepatomegaly and splenomegaly. The etiologic agent, P. multocida serotype 1, was recovered from 77 of 136 carcasses examined, and confirmed or probable avian cholera was diagnosed in 85 cases. Mortality observed in scavenging gull species was disproportionately high relative to their abundance, particularly when compared to nonscavenging species. The presence of feather shafts in the ventricular lumen of the majority of larid carcasses diagnosed with avian cholera suggests scavenging of birds that died from avian cholera as a major mode of transmission. This documentation of an outbreak of avian cholera in a North American pelagic environment affecting primarily scavenging gulls indicates that offshore marine environments may be a component of avian cholera dynamics.
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| 15. |
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| 16. |
- Wille, Michelle, et al.
(författare)
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High Prevalence and Putative Lineage Maintenance of Avian Coronaviruses in Scandinavian Waterfowl
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Coronaviruses (CoVs) are found in a wide variety of wild and domestic animals, and constitute a risk for zoonotic and emerging infectious disease. In poultry, the genetic diversity, evolution, distribution and taxonomy of some coronaviruses have been well described, but little is known about the features of CoVs in wild birds. In this study we screened 764 samples from 22 avian species of the orders Anseriformes and Charadriiformes in Sweden collected in 2006/2007 for CoV, with an overall CoV prevalence of 18.7%, which is higher than many other wild bird surveys. The highest prevalence was found in the diving duck-smainly Greater Scaup (Aythya marila; 51.5%)-and the dabbling duck Mallard (Anas platyrhynchos; 19.2%). Sequences from two of the Greater Scaup CoV fell into an infrequently detected lineage, shared only with a Tufted Duck (Aythya fuligula) CoV. Coronavirus sequences from Mallards in this study were highly similar to CoV sequences from the sample species and location in 2011, suggesting long-term maintenance in this population. A single Black-headed Gull represented the only positive sample from the order Charadriiformes. Globally, Anas species represent the largest fraction of avian CoV sequences, and there seems to be no host species, geographical or temporal structure. To better understand the eitiology, epidemiology and ecology of these viruses more systematic surveillance of wild birds and subsequent sequencing of detected CoV is imperative.
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| 17. |
- Wille, Michelle, et al.
(författare)
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No evidence for homosubtypic immunity of influenza H3 in Mallards following vaccination in a natural experimental system
- 2017
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Ingår i: Molecular Ecology. - : Wiley-Blackwell. - 0962-1083 .- 1365-294X. ; 26:5, s. 1420-1431
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Tidskriftsartikel (refereegranskat)abstract
- The Mallard (Anas platyrhynchos) is an important reservoir species for influenza A viruses (IAV), and in this host, prevalence and virus diversity are high. Studies have demonstrated the presence of homosubtypic immunity, where individuals are unlikely to be reinfected with the same subtype within an autumn season. Further, evidence for heterosubtypic immunity exists, whereby immune responses specific for one subtype offer partial or complete protection against related HA subtypes. We utilized a natural experimental system to determine whether homo- or heterospecific immunity could be induced following experimental vaccination. Thirty Mallards were vaccinated with an inactivated H3, H6 or a sham vaccine and after seroconversion were exposed to naturally infected wild conspecifics. All ducks were infected within 2days and had both primary and secondary infections. Overall, there was no observable difference between groups; all individuals were infected with H3 and H10 IAV. At the cessation of the experiment, most individuals had anti-NP antibodies and neutralizing antibodies against H10. Not all individuals had H3 neutralizing antibodies. The isolated H3 IAVs revealed genetic dissimilarity to the H3 vaccine strain, specifically substitutions in the vicinity of the receptor-binding site. There was no evidence of vaccine-induced homosubtypic immunity to H3, a likely result of both a poor H3 immune response in the ducks and H3 immune escape. Likewise, there was no observed heterosubtypic protection related to H6 vaccination. This study highlights the need for experimental approaches to assess how exposure to pathogens and resulting immune processes translates to individual and population disease dynamics.
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| 18. |
- Wille, Michelle, et al.
(författare)
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Of Ducks and Men : Ecology and Evolution of a Zoonotic Pathogen in a Wild Reservoir Host
- 2017
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Ingår i: Modeling the Transmission and Prevention of Infectious Disease. - Cham : Springer. - 2366-3324. - 9783319606149 - 9783319606163 ; , s. 247-286
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Bokkapitel (refereegranskat)abstract
- A hallmark of disease is that most pathogens are able to infect more than one host species. However, for most pathogens, we still have a limited understanding of how this affects epidemiology, persistence and virulence of infections—including several zoonotic pathogens that reside in wild animal reservoirs and spillover into humans. In this chapter, we review the current knowledge of mallard (Anas platyrhynchos) as host for pathogens. This species is widely distributed, often occupying habitats close to humans and livestock, and is an important game bird species and the ancestor to domestic ducks—thereby being an excellent model species to highlight aspects of the wildlife, domestic animal interface and the relevance for human health. We discuss mallard as host for a range of pathogens but focus more in depth of it as a reservoir host for influenza A virus (IAV). Over the last decades, IAV research has surged, prompted in part to the genesis and spread of highly pathogenic virus variants that have been devastating to domestic poultry and caused a number of human spillover infections. The aim of this chapter is to synthesise and review the intricate interactions of virus, host and environmental factors governing IAV epidemiology and evolution.
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| 19. |
- Wille, Michelle, et al.
(författare)
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RNAlater (R) is a viable storage option for avian influenza sampling in logistically challenging conditions
- 2018
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Ingår i: Journal of Virological Methods. - : ELSEVIER SCIENCE BV. - 0166-0934 .- 1879-0984. ; 252, s. 32-36
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Tidskriftsartikel (refereegranskat)abstract
- Surveillance of wild birds is critical in monitoring for highly pathogenic avian influenza A viruses (ATVs). However, a successful surveillance regime requires proper treatment of samples in the field - rapid placement of samples in -80 degrees C and subsequent maintenance of cold-chain. Given the logistical difficulties of this, many avian taxa and/or geographic locations are not sampled, or, when sampled may result in false negatives due to poor sample treatment in the field. Here, we assessed the utility of RNAlater (R) as a stabilization agent for AIV sampling. We found no difference in real time PCR performance between virus transport media at optimal conditions and RNAlater (R) at -80 degrees C, -20 degrees C, 4 degrees C or room temperature up to two weeks, at either low or high virus load. Not only was RNAlater (R) useful in comparison of spiked samples or those from duck experiments, it was employed successfully in a field study of backyard birds in China. We detected AIV in cloacal and oropharyngeal samples from chickens and a sample with a low Cq was successfully subtyped as H9, although sample storage conditions were suboptimal. Thus, despite limitations in downstream characterization such virus isolation and typing, RNAlater (R) is a viable option for AIV sampling under logistically challenging circumstances.
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| 20. |
- Wille, Michelle, et al.
(författare)
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Temporal dynamics, diversity, and interplay in three components of the virodiversity of a Mallard population : Influenza A virus, avian paramyxovirus and avian coronavirus
- 2015
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Ingår i: Infection, Genetics and Evolution. - : Elsevier BV. - 1567-1348 .- 1567-7257. ; 29, s. 129-137
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Tidskriftsartikel (refereegranskat)abstract
- Multiple infections, or simultaneous infection of a host with multiple parasites, are the rule rather than the exception. Interactions between co-occurring pathogens in a population may be mutualistic, competitive or facilitative. For some pathogen combinations, these interrelated effects will have epidemiological consequences; however this is as yet poorly incorporated into practical disease ecology. For example, screening of Mallards for influenza A viruses (IAV) have repeatedly revealed high prevalence and large subtype diversity in the Northern Hemisphere. Other studies have identified avian paramyxovirus type 1 (APMV-1) and coronaviruses (CoVs) in Mallards, but without making inferences on the larger viral assemblage. In this study we followed 144 wild Mallards across an autumn season in a natural stopover site and constructed infection histories of IAV, APMV-1 and CoV. There was a high prevalence of IAV, comprising of 27 subtype combinations, while APMV-1 had a comparatively low prevalence (with a peak of 2%) and limited strain variation, similar to previous findings. Avian CoVs were common, with prevalence up to 12%, and sequence analysis identified different putative genetic lineages. An investigation of the dynamics of co-infections revealed a synergistic effect between CoV and IAV, whereby Coy prevalence was higher given that the birds were co-infected with IAV. There were no interactive effects between IAV and APMV-1. Disease dynamics are the result of an interplay between parasites, host immune responses, and resources; and is imperative that we begin to include all factors to better understand infectious disease risk. (C) 2014 Elsevier B.V. All rights reserved.
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| 21. |
- Wille, Michelle, et al.
(författare)
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Urbanization and the dynamics of RNA viruses in Mallards (Anas platyrhynchos)
- 2017
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Ingår i: Infection, Genetics and Evolution. - : Elsevier BV. - 1567-1348 .- 1567-7257. ; 51, s. 89-97
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Tidskriftsartikel (refereegranskat)abstract
- Urbanization is intensifying worldwide, and affects the epidemiology of infectious diseases. However, the effect of urbanization on natural host-pathogen systems remains poorly understood. Urban ducks occupy an interesting niche in that they directly interact with both humans and wild migratory birds, and either directly or indirectly with food production birds. Here we have collected samples from Mallards (Anas platyrhynchos) residing in a pond in central Uppsala, Sweden, from January 2013 to January 2014. This artificial pond is kept ice-free during the winter months, and is a popular location where the ducks are fed, resulting in a resident population of ducks year-round. Nine hundred and seventy seven (977) fecal samples were screened for RNA viruses including: influenza A virus (IAV), avian paramyxovirus 1, avian coronavirus (CoV), and avian astrovirus (AstroV). This intra-annual dataset illustrates that these RNA viruses exhibit similar annual patterns to IAV, suggesting similar ecological factors are at play. Furthermore, in comparison to wild ducks, autumnal prevalence of IAV and CoV are lower in this urban population. We also demonstrate that AstroV might be a larger burden to urban ducks than IAV, and should be better assessed to demonstrate the degree to which wild birds contribute to the epidemiology of these viruses. The presence of economically relevant viruses in urban Mallards highlights the importance of elucidating the ecology of wildlife pathogens in urban environments, which will become increasingly important for managing disease risks to wildlife, food production animals, and humans.
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| 22. |
- Wille, Michelle
(författare)
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Viruses on the wing : evolution and dynamics of influenza A virus in the Mallard reservoir
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis explores the evolution of avian influenza A viruses (IAV), as well as host-pathogen interactions between these viruses and their main reservoir host, the Mallard (Anas platyrhynchos). IAV is a genetically diverse, multi-host virus and wild birds, particularly dabbling ducks, are the natural reservoir. At our study site, up to 30% of migratory Mallards are infected with IAV during an autumn season, and host a large number of virus subtypes. IAV diversity is driven by two main mechanisms: mutation, driving genetic drift; and reassortment following co-infection, resulting in genetic shift. Reassortment is pervasive within an autumn season, both across multiple subtypes and within a single subtype. It is a key genetic feature in long-term maintenance of common subtypes, as it allows for independent lineage turn-over, generating novel genetic constellations. I hypothesize that the decoupling of successful constellations and generation of novel annual constellations enables viruses to escape herd immunity; these genetic changes must confer antigenic change for the process to be favourable. Indeed, in an experiment utilizing vaccines, circulating viruses escaped homosubtypic immunity, resulting in the proliferation of infections with the same subtype as the vaccine. While the host plays an important role in shaping IAV evolutionary genetics, one must consider that Mallards are infected with a multitude of other microorganisms. Here, Mallards were infected with IAV, gamma coronaviruses, and avian paramyxovirus type 1 simultaneously, and we found a putative synergistic interaction between IAV and gamma coronaviruses. Mallards occupy the interface between humans, poultry, and wild birds, and are the reservoir of IAV diversity. New incursions of highly pathogenic H5 viruses to both Europe and North America reaffirms the role of wild birds, particularly waterfowl, in diffusion of viruses spatially. Using European low pathogenic viruses and Mallard model, this thesis contributes to aspects of epidemiology, ecology, and evolutionary dynamics of waterfowl viruses, particularly IAV
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| 23. |
- Wille, Michelle, et al.
(författare)
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Where do all the subtypes go? : Temporal dynamics of H8-H12 influenza A viruses in waterfowl
- 2018
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Ingår i: Virus Evolution. - : Oxford University Press. - 2057-1577. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- Influenza A virus (IAV) is ubiquitous in waterfowl. In the northern hemisphere IAV prevalence is highest during the autumn and coincides with a peak in viral subtype diversity. Although haemagglutinin subtypes H1-H12 are associated with waterfowl hosts, subtypes H8-H12 are detected very infrequently. To better understand the role of waterfowl in the maintenance of these rare subtypes, we sequenced H8-H12 viruses isolated from Mallards (Anas platyrhynchos) from 2002 to 2009. These rare viruses exhibited varying ecological and phylodynamic features. The Eurasian clades of H8 and H12 phylogenies were dominated by waterfowl sequences; mostly viruses sequenced in this study. H11, once believed to be a subtype that infected charadriiformes (shorebirds), exhibited patterns more typical of common virus subtypes. Finally, subtypes H9 and H10, which have maintained lineages in poultry, showed markedly different patterns: H10 was associated with all possible NA subtypes and this drove HA lineage diversity within years. Rare viruses belonging to subtypes H8-H12 were highly reassorted, indicating that these rare subtypes are part of the broader IAV pool. Our results suggest that waterfowl play a role in the maintenance of these rare subtypes, but we recommend additional sampling of non-traditional hosts to better understand the reservoirs of these rare viruses.
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