| 1. |
- Järhult, Josef D., et al.
(författare)
-
Environmental levels of the antiviral oseltamivir induce development of resistance mutation H274Y in influenza A/H1N1 virus in mallards
- 2011
-
Ingår i: PLOS ONE. - San Francisco, CA : Public Library of Science (PLoS). - 1932-6203. ; 6:9
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 2. |
- Jourdain, Elsa, et al.
(författare)
-
Influenza Virus in a Natural Host, the Mallard : Experimental Infection Data
- 2010
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:1
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 3. |
- Almered Olsson, Gunilla, 1951, et al.
(författare)
-
Food systems sustainability: For whom and by whom? – An examination of different 'food system change' viewpoints
- 2018
-
Ingår i: Development Research Conference 2018: “Rethinking development”, 22–23 August 2018, Gothenburg, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- The United Nations identifies the food crisis as one of the primary overarching challenges facing the international community. Different stakeholders in the food system have widely different perspectives and interests, and challenging structural issues, such as the power differentials among them, remain largely unexamined. These challenges make rational discourse among food system actors from different disciplines, sectors and levels difficult. These challenges can often prevent them from working together effectively to find innovative ways to respond to food security challenges. This means that finding solutions to intractable and stuck issues, such as the food crisis often stall, not at implementation, but at the point of problem identification. Food system sustainability means very different things to different food system actors. These differences in no way undermine or discount the work carried out by these players. However, making these differences explicit is an essential activity that would serve to deepen theoretical and normative project outcomes. Would the impact and reach of different food projects differ if these differences were made explicit? The purpose of this initial part of a wider food system research project is not to search for difference or divergence, with the aim of critique, but rather to argue that by making these differences explicit, the overall food system project engagement will be made more robust, more inclusive and more encompassing. This paper starts with some discussion on the different food system perspectives, across scales, regions and sectors but focuses primarily on the design of processes used to understand these divergent and at times contradictory views of what a sustainable food system may be. This paper draws on ongoing work within the Mistra Urban Futures project, using the food system projects in cities as diverse as Cape Town, Manchester, Gothenburg and Kisumu as sites for this enquiry.
|
|
| 4. |
- Gillman, Anna, et al.
(författare)
-
Oseltamivir-Resistant Influenza A (H1N1) Virus Strain with an H274Y Mutation in Neuraminidase Persists without Drug Pressure in Infected Mallards
- 2015
-
Ingår i: Applied and Environmental Microbiology. - : American Society for Microbiology. - 0099-2240 .- 1098-5336. ; 81:7, s. 2378-2383
-
Tidskriftsartikel (refereegranskat)abstract
- Influenza A virus (IAV) has its natural reservoir in wild waterfowl and emerging human IAVs often contain gene segments from avian viruses. The active drug metabolite of oseltamivir (oseltamivir carboxylate (OC)), stockpiled as Tamiflu® for influenza pandemic preparedness, is not removed by conventional sewage treatment and has been detected in river water. There, it may there exert evolutionary pressure on avian IAV in waterfowl, resulting in development of resistant viral variants. A resistant avian IAV can circulate among wild birds only if resistance does not restrict viral fitness and if the resistant virus can persist without continuous drug pressure. In this in vivo Mallard (Anas platyrhynchos) study we tested if an OC-resistant avian IAV strain (A(H1N1)/NA-H274Y) could retain resistance while drug pressure was gradually removed. Successively infected Mallards were exposed to decreasing levels of OC, and fecal samples were analyzed for neuraminidase sequence and phenotypic resistance. No reversion to wild-type virus was observed during the experiment, which included 17 days of viral transmission in 10 ducks exposed to OC concentrations below resistance induction levels. We conclude that resistance in avian IAV, induced by OC exposure of the natural host, can persist in absence of the drug. Thus, there is a risk that human pathogenic IAVs that evolve from IAVs circulating among wild birds may contain resistance mutations. An oseltamivir resistant pandemic IAV would be a substantial public health threat. Therefore, our observations underscore the need for prudent oseltamivir use, upgraded sewage treatment and resistance surveillance of IAV in wild birds.
|
|
| 5. |
- Muradrasoli, Shaman, et al.
(författare)
-
Prevalence and phylogeny of coronaviruses in wild birds from the Bering Strait area (Beringia)
- 2010
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:10
-
Tidskriftsartikel (refereegranskat)abstract
- Coronaviruses (CoVs) can cause mild to severe disease in humans and animals, their host range and environmental spread seem to have been largely underestimated, and they are currently being investigated for their potential medical relevance. Infectious bronchitis virus (IBV) belongs to gamma-coronaviruses and causes a costly respiratory viral disease in chickens. The role of wild birds in the epidemiology of IBV is poorly understood. In the present study, we examined 1,002 cloacal and faecal samples collected from 26 wild bird species in the Beringia area for the presence of CoVs, and then we performed statistical and phylogenetic analyses. We detected diverse CoVs by RT-PCR in wild birds in the Beringia area. Sequence analysis showed that the detected viruses are gamma-coronaviruses related to IBV. These findings suggest that wild birds are able to carry gamma-coronaviruses asymptomatically. We concluded that CoVs are widespread among wild birds in Beringia, and their geographic spread and frequency is higher than previously realised. Thus, Avian CoV can be efficiently disseminated over large distances and could be a genetic reservoir for future emerging pathogenic CoVs. Considering the great animal health and economic impact of IBV as well as the recent emergence of novel coronaviruses such as SARS-coronavirus, it is important to investigate the role of wildlife reservoirs in CoV infection biology and epidemiology.
|
|
| 6. |
- Mårtensson, Fredrika, et al.
(författare)
-
The role of greenery for physical activity play at school grounds
- 2014
-
Ingår i: Urban Forestry & Urban Greening. - : Elsevier BV. - 1618-8667 .- 1610-8167. ; 13:1, s. 103-113
-
Tidskriftsartikel (refereegranskat)abstract
- Greenery is assumed to promote physical activity at school grounds by facilitating open and flexible play situations that engage many children. The role of greenery for school ground activity was investigated at two schools, one of which contained a substantial amount of greenery and the other one little greenery. All in all 197 children from 4th (10-11 years) and 6th grade (12-13 years), were involved in a one week field study, documenting self-reported school ground use, their favourite places and favourite activities and counting their steps by pedometer. The most common school ground activities were related to the use of balls as part of different sports, games and other playful activity. The more extensive green areas belonged to children's favourite places, but were little used, whereas settings with a mix of green and built elements in proximity to buildings were well-used favourites. Physical activity in steps was similar at the two schools, but on average girls got less of the activity they need during recess. Greenery was found important by contributing to settings attractive to visit for girls as well as boys and for younger as well as older children, if located in ways that also supported peer interaction and various games. (C) 2013 Elsevier G'mbH. All rights reserved.
|
|
| 7. |
- Ebitu, Larmbert, et al.
(författare)
-
Citizen science for sustainable agriculture : A systematic literature review
- 2021
-
Ingår i: Land use policy. - : Elsevier. - 0264-8377 .- 1873-5754. ; 103
-
Forskningsöversikt (refereegranskat)abstract
- Farmers as volunteers in research could potentially provide a rich resource for exploring sustainable agricultural research questions. To discern emerging patterns in citizen science-based studies on topics with relevance for sustainable agriculture and reveal salient challenges and opportunities for conducting such studies, we conducted a literature review of 27 articles from the period 2004–2019 of 250 publications screened from Google Scholar. These articles were thematically grouped under the topics: Soil health, climate adaptation, pest/pathogen monitoring, invasive species, inputs and outputs and pollination. Participants’ characteristics, motivations, study design and project outcomes in the reviewed articles were summarized and discussed. Both observational and experimental studies were represented in the articles, while emerging trends point towards field experimentation and ‘Large-N′ trials by lay farmers. Crowdsourcing lends itself to projects where the main role of the public is local visual observations and reporting, such as in pest/pathogen monitoring. Challenges included methodological issues such as validation procedures, but above all motivation, recruitment, and retention of volunteers. Despite the importance of participatory approaches for deeper citizen involvement for sustainability transitions and for the quality of knowledge outcomes, the role of citizens was overall restricted to data collection. Several of the methodologies proposed would be difficult to implement in low-income countries, and relatively few studies pertained to agricultural concerns of the global South. To lend value to farmers' time, we recommend projects relevant to livelihoods, health issues or local farming problems, accompanied by well-structured data feedback protocols, routing study results back to farmers.
|
|
| 8. |
- Augustsson, Anna, et al.
(författare)
-
Challenges in assessing the health risks of consuming vegetables in metal-contaminated environments
- 2018
-
Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 113, s. 269-280
-
Tidskriftsartikel (refereegranskat)abstract
- A great deal of research has been devoted to the characterization of metal exposure due to the consumption of vegetables from urban or industrialized areas. It may seem comforting that concentrations in crops, as well as estimated exposure levels, are often found to be below permissible limits. However, we show that even a moderate increase in metal accumulation in crops may result in a significant increase in exposure. We also highlight the importance of assessing exposure levels in relation to a regional baseline. We have analyzed metal (Pb, Cd, As) concentrations in nearly 700 samples from 23 different vegetables, fruits, berries and mushrooms, collected near 21 highly contaminated industrial sites and from reference sites. Metal concentrations generally complied with permissible levels in commercial food and only Pb showed overall higher concentrations around the contaminated sites. Nevertheless, probabilistic exposure assessments revealed that the exposure to all three metals was significantly higher in the population residing around the contaminated sites, for both low-, medianand high consumers. The exposure was about twice as high for Pb and Cd, and four to six times as high for As. Since vegetable consumption alone did not result in exposure above tolerable intakes, it would have been easy to conclude that there is no risk associated with consuming vegetables grown near the contaminated sites. However, when the increase in exposure is quantified, its potential significance is harder to dismiss - especially when considering that exposure via other routes may be elevated in a similar way.
|
|
| 9. |
- Benavent-Celma, Clara, et al.
(författare)
-
Current practices and emerging possibilities for reducing the spread of oomycete pathogens in terrestrial and aquatic production systems in the European Union
- 2022
-
Ingår i: Fungal Biology Reviews. - : Elsevier. - 1749-4613 .- 1878-0253. ; 40, s. 19-36
-
Tidskriftsartikel (refereegranskat)abstract
- Diseases caused by oomycete pathogens are a global threat to forestry, agriculture and aquaculture. Because of their complex life cycles, characterised by dormant resting structures that enable their survival for years under hostile environmental conditions, reducing the spread of oomycetes is a challenging task. In this review, we present an overview of this challenge, starting from the need to understand the natural and anthropogenic dispersal pathways of these pathogens. Focusing on the European Union, we explore current legislation that forms a backbone for biosecurity protocols against the spread of oomycetes through trade and transport. We discuss the options for prevention, containment and long-term management of oomycetes in different production settings, emphasising the importance of prevention as the most cost-efficient strategy to reduce the spread of these pathogens. Finally, we highlight some of the new and emerging technologies and strategies as potential tools in the integrated pest management of animal and plant diseases caused by oomycetes. We emphasise the urgency of actions to halt the global spread of these pathogens.
|
|
| 10. |
- Jensen, Anna M, et al.
(författare)
-
Shrubs protect oak seedlings against ungulate browsing in temperate broadleaved forests of conservation interest: A field experiment
- 2012
-
Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 266, s. 187-193
-
Tidskriftsartikel (refereegranskat)abstract
- In many oak-rich temperate broadleaved forests of conservation value, high ungulate browsing pressure restricts oak regeneration. We examined the protection of oak (Quercus sp.) seedlings from browsing provided by naturally occurring shrubs in 10 forests across southern Sweden over 3 years. We planted oak seedlings in four plots in each forest; two with naturally regenerated shrubs and two with no shrubs. Ungulate browsers were excluded from two plots at each site, one with and one without shrubs. Fencing provided the best protection against ungulate browsers for the seedlings. The probability of a seedling being browsed (browsing frequency) was approximately 20% units lower for individuals growing among shrubs than for individuals growing in the absence of shrubs. When browsing did occur, the intensity (measured as a reduction in height growth) was significantly lower for seedlings in shrubs. Regression analyses showed that browsing frequency increased on seedlings in tall shrubs, and decreased on seedlings that had been browsed previously. Browsing intensity decreased if the seedling grew in tall and dense shrubs. Browsing frequency and intensity increased on oak seedlings that over topped the shrub canopy. Increased abundance of the prickled Rubus idaeus and Rubus fruticosus coll. in plots with shrubs did not affect browsing frequency and intensity. Two and a half years after planting, oak seedling mortality increased by the presence of shrubs. Although shrubs restricted oak seedling growth, we conclude that shrubs initially facilitated oak regeneration by concealment, and subsequently by numeric dilution. Shrubs may be used to reduce browsing damages if long-term evaluation indicates a net positive outcome for oak survival and growth.
|
|
