Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit
The artic fox is under threat of extermination in Europe. The population decreased strongly at the beginning of the twentieth century because of intensive hunting. The artic fox was placed under protection by law 1928 in Sweden but despite this the population has had difficultly to recover. This can...
| Autor principal: | |
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| Formato: | L3 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231)
2009
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| Materias: |
| _version_ | 1855571884324683776 |
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| author | Thörnvall, Helena |
| author_browse | Thörnvall, Helena |
| author_facet | Thörnvall, Helena |
| author_sort | Thörnvall, Helena |
| collection | Epsilon Archive for Student Projects |
| description | The artic fox is under threat of extermination in Europe. The population decreased strongly at the beginning of the twentieth century because of intensive hunting. The artic fox was placed under protection by law 1928 in Sweden but despite this the population has had difficultly to recover. This can depend on several reasons, but the main threats are shortage of food and competition from the red fox. Along with Norway and Finland, Sweden has carried out a project called SEFALO (Saving the Endangered Fennoscandian Alopex lagopus), whose objectives were to prevent continued decreased populationnumbers and through, for example supplementary feeding, help the population to recover. 10 years ago approximately only 40 adult artic foxes were present in Sweden. Last summer, when the SEFALO-project was completed, the number was calculated to about 140 adult individuals.
In an attempt to increase the number of individuals a breeding programme with wild captured foxes started in 1992. Unfortunately, the majority of the foxes developed central nervous symptoms and either died or were euthanized. Many of these foxes had serious encephalitis, but researchers has not so far found the reason to the disease. One have looked for the most common infectious causes of encephalitis, but without positive results.
The main aim with this study was to examine occurrence of unknown viruses in Swedish artic foxes with encephalitis, to if possible find a causative agent of this disease. The study included four artic foxes who had shown neurological symptoms. Brainmaterial was examined from three of the foxes and CSF from one of them. DNA and RNA were extracted from the clinical material and through the use of primers with random sequences, the nucleotidesequences were amplified with the aid of PCR. The sequences were then cloned in E.coli-cells before sequencing was carried out.
The result of this study showed that the material that was used did not for certain contain any agents that could have caused the artic foxes' disease. There are different reasons why any virus couldn't be identified. The virus concentration is often very low, especially in very sick animals, and this makes the detection more difficult. Virus can also be present in the animal but not in the tissue sample that is examined or the virus can exist in an other organ. To some extent this work supports earlier findings of a herpesvirus as a possible causative agent.
In order for the artic fox population to survive and to continue to increase in number, futher actions are required and also additional research about the causative agent behind the disease. |
| format | L3 |
| id | RepoSLU11498 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2009 |
| publishDateSort | 2009 |
| publisher | SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231) |
| publisherStr | SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231) |
| record_format | eprints |
| spelling | RepoSLU114982017-10-04T07:57:07Z Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit Thörnvall, Helena fjällräv encefalit okända virus The artic fox is under threat of extermination in Europe. The population decreased strongly at the beginning of the twentieth century because of intensive hunting. The artic fox was placed under protection by law 1928 in Sweden but despite this the population has had difficultly to recover. This can depend on several reasons, but the main threats are shortage of food and competition from the red fox. Along with Norway and Finland, Sweden has carried out a project called SEFALO (Saving the Endangered Fennoscandian Alopex lagopus), whose objectives were to prevent continued decreased populationnumbers and through, for example supplementary feeding, help the population to recover. 10 years ago approximately only 40 adult artic foxes were present in Sweden. Last summer, when the SEFALO-project was completed, the number was calculated to about 140 adult individuals. In an attempt to increase the number of individuals a breeding programme with wild captured foxes started in 1992. Unfortunately, the majority of the foxes developed central nervous symptoms and either died or were euthanized. Many of these foxes had serious encephalitis, but researchers has not so far found the reason to the disease. One have looked for the most common infectious causes of encephalitis, but without positive results. The main aim with this study was to examine occurrence of unknown viruses in Swedish artic foxes with encephalitis, to if possible find a causative agent of this disease. The study included four artic foxes who had shown neurological symptoms. Brainmaterial was examined from three of the foxes and CSF from one of them. DNA and RNA were extracted from the clinical material and through the use of primers with random sequences, the nucleotidesequences were amplified with the aid of PCR. The sequences were then cloned in E.coli-cells before sequencing was carried out. The result of this study showed that the material that was used did not for certain contain any agents that could have caused the artic foxes' disease. There are different reasons why any virus couldn't be identified. The virus concentration is often very low, especially in very sick animals, and this makes the detection more difficult. Virus can also be present in the animal but not in the tissue sample that is examined or the virus can exist in an other organ. To some extent this work supports earlier findings of a herpesvirus as a possible causative agent. In order for the artic fox population to survive and to continue to increase in number, futher actions are required and also additional research about the causative agent behind the disease. Fjällräven är en utrotningshotad art i Europa. Populationen minskade kraftigt i början av 1900-talet på grund av mycket intensiv jakt. Sverige fridlyste fjällräven 1928 men trots detta har stammen haft svårt att återhämta sig. Detta kan bero på flera orsaker, men de främsta är brist på föda och konkurrens från rödräven. Tillsammans med Norge och Finland har Sverige genomfört ett projekt som kallas SEFALO (Saving the Endangered Fennoscandian Alopex lagopus), vars mål har varit att förhindra fortsatt minskat populationsantal samt genom exempelvis stödutfodring hjälpa stammen att återhämta sig. För 10 år sedan fanns endast ca 40 vuxna fjällrävar i Sverige. I somras, när SEFALO-projektet avslutades, beräknades antalet till ungefär 140 vuxna individer. I ett försök att öka antalet individer påbörjades 1992 ett uppfödningsförsök av infångade vilda rävar. Tyvärr utvecklade flertalet av rävarna centralnervösa symtom och antingen avled eller avlivades. Många av dessa rävar visade sig ha allvarlig encefalit, men forskare har hittills inte kunnat hitta orsaken till sjukdomen. Man har undersökt förekomst av de vanligaste infektiösa agens som orsakar encefalit, men utan positiva resultat. Huvudsyftet med detta arbete var att undersöka förekomst av okända virus hos svenska fjällrävar med encefalit, för att om möjligt finna ett agens som orsak till sjukdomen. I studien ingick fyra fjällrävar som visat neurologiska symtom. Från tre av rävarna undersöktes hjärnvävnad och från en undersöktes CSF. DNA och RNA extraherades från det kliniska materialet och genom användning av primers med slumpmässiga sekvenser skedde amplifiering av nukleotidsekvenserna med hjälp av PCR. Sekvenserna klonades sedan i E.coli-bakterier innan sekvensering utfördes. Det material som användes i denna studie visade sig dock inte innehålla några agens som med säkerhet kan vara orsak till fjällrävarnas sjukdom. Det kan finnas olika anledningar till att inga virus med stor sannolikhet kunde identifieras. Viruskoncentrationen är oftast mycket låg, framför allt hos svårt sjuka djur, vilket försvårar detektionen. Virus kan även förekomma hos individen men inte i just den vävnadsbit som undersöks eller så finns viruset i ett annat organ. Till viss del stöder dock resultat av detta arbete tidigare studier där herpesvirussekvenser hittats. För att fjällrävsstammen ska bevaras och fortsätta att öka, krävs fortsatta åtgärder samt ytterligare forskning om orsaken till sjukdomen. SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231) 2009 L3 swe eng https://stud.epsilon.slu.se/11498/ |
| spellingShingle | fjällräv encefalit okända virus Thörnvall, Helena Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit |
| title | Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit |
| title_full | Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit |
| title_fullStr | Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit |
| title_full_unstemmed | Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit |
| title_short | Undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit |
| title_sort | undersökning av förekomst av okända virus hos svenska fjällrävar med encefalit |
| topic | fjällräv encefalit okända virus |