| 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. |
- Marklinder, Ingela, et al.
(författare)
-
Food safety knowledge, sources thereof and self-reported behaviour among university students in Sweden
- 2020
-
Ingår i: Food Control. - : Elsevier. - 0956-7135 .- 1873-7129. ; 113
-
Tidskriftsartikel (refereegranskat)abstract
- International studies have noted shortcomings in food safety knowledge and behaviour among university students. In general students do not constitute a pronounced risk group but there are wider implications. In a foreseeable future some of them will become pregnant and a majority will be responsible for vulnerable groups in their near environment. A crucial question exists, therefore, about their food safety knowledge and safe food handling practices. The aim of this study is to investigate food safety knowledge, sources thereof and self-reported food safety behavior among university students in Sweden. A quantitative study design using a web-based questionnaire was chosen as the data collection method. The questionnaire was distributed through social media and e-mail. Among the 606 respondents from 24 Swedish universities 80% were 18-30 years and 78% were women. The average number of correct answers on the knowledge questions was 7.61 out of 12 (63.4%). The foremost source of food safety knowledge was "Family and friends" (45%). Just 21.1% reported Food safety education as a source, although 35.6% had experience of a course in food hygiene/safety and/or microbiology. Respondents who reported "Family and friends" to be the foremost food safety source of knowledge also got a significantly lower rate of correct answers. Students who estimated their food safety knowledge to be good also had more correct answers. Experience of food safety education at secondary school/university/working place/polytechnic school significantly correlated with more correct answers on the knowledge questions and indicated a safer self-reported behaviour. Those with fewer correct answers also reported more unfavourable behaviours. The present study indicates that education promotes more optimal behaviors. The authors would suggest a more systematic food safety education at younger ages.
|
|
| 3. |
- Stedt, Kristoffer, 1991, et al.
(författare)
-
Post-harvest cultivation with seafood process waters improves protein levels of Ulva fenestrata while retaining important food sensory attributes
- 2022
-
Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745.
-
Tidskriftsartikel (refereegranskat)abstract
- Seaweed aquaculture can provide the growing human population with a sustainable source of proteins. Sea-based cultivation is an effective method for farming seaweeds on a large scale and can yield high biomass output. However, the quality and biochemical composition of the biomass is seasonally dependent, which limits the harvests to certain periods of the year. Here we show the possibility to extend the sea-based cultivation season of Ulva fenestrata when aiming for high protein levels, by post-harvest treatment in herring production process waters. We harvested U. fenestrata at an optimal period in terms of yield, but suboptimal in terms of protein content. We then cultivated the seaweed in onshore tank systems with the nutrient-rich process waters for 14 days. We monitored biomass yield, crude protein content, amino acid composition, and content of the health concerning metals arsenic, mercury, lead, and cadmium, as well as the sensory properties of the dried biomass. After cultivation in the process waters, biomass yields were 30 - 40% higher (210 – 230 g fresh weight) compared to in seawater (160 g fresh weight). Also, the crude protein and amino acid content increased three to five times in the process waters, reaching 12 - 17 and 15 – 21% dry weight, respectively. The protein enriched biomass followed food graded standards for heavy metal content, and consumption of the biomass does not exceed health based reference points. Additionally, no sensory attributes regarded as negative were found. This rapid, post-harvest treatment can help extend the cultivation season of sea-based seaweed farms, maximizing their output of sustainable proteins.
|
|
| 4. |
- 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.
|
|
| 5. |
|
|
| 6. |
- 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.
|
|
| 7. |
- Marklinder, Ingela, 1959-, et al.
(författare)
-
A Structural Equation Model Demonstrating the Relationship between Food Safety Background, Knowledge, Attitudes and Behaviour among Swedish Students
- 2022
-
Ingår i: Foods. - : MDPI. - 2304-8158. ; 11:11
-
Tidskriftsartikel (refereegranskat)abstract
- Traditionally, food safety knowledge has been seen as a factor in improving food safety behaviour. However, the relationship between knowledge and behavior is complex. The aim of the present study was to investigate self-reported data from 408 university students regarding food safety background, knowledge, attitudes, and behaviour using Structural Equation Model (SEM) to examine the influence of different factors on food safety behaviour. The SEM was applied to four factors derived from the data: Background, Knowledge, Attitude and Behaviour. The novelty of this current investigation is the inclusion of the Background factor (genus; experience of cooking and handling different food items; experience of a food safety education course; the foremost sources of food safety knowledge). The factors were constructed from variables with sufficient factor loadings and set up in a predetermined structure confirmed to be valid in previous studies. The results, demonstrated as regression coefficients between factors, confirm that the Background factor strongly influenced Knowledge (0.842). The Knowledge factor, in turn, strongly affected Attitude (0.605), while it did not directly affect Behaviour (0.301) in the same way as Attitude. Attitude had a stronger influence on Behaviour (0.438) than Knowledge. Thus, the Attitude factor seemed to play a mediating role between Knowledge and Behaviour. This indicates that students ' attitudes towards the importance of food safety may have an impact on their food safety behavior, which should have implications for the development of food safety education. This warrants further investigation and practical development.
|
|
| 8. |
- Marklinder, Ingela, 1959-, et al.
(författare)
-
Food safety knowledge, sources thereof and self-reported behaviour among university students in Sweden
- 2020
-
Ingår i: Food Control. - : Elsevier. - 0956-7135 .- 1873-7129. ; 113
-
Tidskriftsartikel (refereegranskat)abstract
- International studies have noted shortcomings in food safety knowledge and behaviour among university students. In general students do not constitute a pronounced risk group but there are wider implications. In a foreseeable future some of them will become pregnant and a majority will be responsible for vulnerable groups in their near environment. A crucial question exists, therefore, about their food safety knowledge and safe food handling practices.The aim of this study is to investigate food safety knowledge, sources thereof and self-reported food safety behavior among university students in Sweden.A quantitative study design using a web-based questionnaire was chosen as the data collection method. The questionnaire was distributed through social media and e-mail.Among the 606 respondents from 24 Swedish universities 80% were 18-30 years and 78% were women. The average number of correct answers on the knowledge questions was 7.61 out of 12 (63.4%). The foremost source of food safety knowledge was "Family and friends" (45%). Just 21.1% reported Food safety education as a source, although 35.6% had experience of a course in food hygiene/safety and/or microbiology. Respondents who reported "Family and friends" to be the foremost food safety source of knowledge also got a significantly lower rate of correct answers. Students who estimated their food safety knowledge to be good also had more correct answers. Experience of food safety education at secondary school/university/working place/polytechnic school significantly correlated with more correct answers on the knowledge questions and indicated a safer self-reported behaviour. Those with fewer correct answers also reported more unfavourable behaviours. The present study indicates that education promotes more optimal behaviors. The authors would suggest a more systematic food safety education at younger ages.
|
|
| 9. |
|
|
| 10. |
- Callaghan, Terry, et al.
(författare)
-
Multi-Decadal Changes in Tundra Environments and Ecosystems : Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF)
- 2011
-
Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 40:6, s. 705-716
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the responses of tundra systemsto global change has global implications. Most tundraregions lack sustained environmental monitoring and oneof the only ways to document multi-decadal change is toresample historic research sites. The International PolarYear (IPY) provided a unique opportunity for such researchthrough the Back to the Future (BTF) project (IPY project#512). This article synthesizes the results from 13 paperswithin this Ambio Special Issue. Abiotic changes includeglacial recession in the Altai Mountains, Russia; increasedsnow depth and hardness, permafrost warming, andincreased growing season length in sub-arctic Sweden;drying of ponds in Greenland; increased nutrient availabilityin Alaskan tundra ponds, and warming at mostlocations studied. Biotic changes ranged from relativelyminor plant community change at two sites in Greenland tomoderate change in the Yukon, and to dramatic increasesin shrub and tree density on Herschel Island, and in subarcticSweden. The population of geese tripled at one sitein northeast Greenland where biomass in non-grazed plotsdoubled. A model parameterized using results from a BTFstudy forecasts substantial declines in all snowbeds andincreases in shrub tundra on Niwot Ridge, Colorado overthe next century. In general, results support and provideimproved capacities for validating experimental manipulation,remote sensing, and modeling studies.
|
|
