Audun Slettan

• Halvorsen, Silje; Korslund, Lars; Mattingsdal, Morten & Slettan, Audun (2023). Estimating number of European eel (Anguilla anguilla) individuals using environmental DNA and haplotype count in small rivers. Ecology and Evolution. ISSN 2045-7758. 13(2). doi: 10.1002/ece3.9785. Full text in Research Archive Show summary

  Knowledge about population genetic data is important for effective conservation management. Genetic research traditionally requires sampling directly from the organism, for example tissue, which can be challenging, time-consuming, and harmful to the animal. Environmental DNA (eDNA) approaches offer a way to sample genetic material noninvasively. In attempts to estimate population size of aquatic species using eDNA, researchers have found positive correlations between biomass and eDNA concentrations, but the approach is debated because of variations in the production and degrading of DNA in water. Recently, a more accurate eDNA-approach has emerged, focusing on the genomic differences between individuals. In this study, we used eDNA from water samples to estimate the number of European eel (Anguilla anguilla) individuals by examining haplotypes in the mitochondrial D-loop region, both in a closed aquatic environment with 10 eels of known haplotypes and in three rivers. The results revealed that it was possible to find every eel haplotype in the eDNA sample collected from the closed environment. We also found 13 unique haplotypes in the eDNA samples from the three rivers, which probably represent 13 eel individuals. This means that it is possible to obtain genomic information from European eel eDNA in water; however, more research is needed to develop the approach into a possible future tool for population quantification.

• Strand, Leif Åge; Måseide, Heini T.S.; Gaupeland, Stian; Johansen, Beate Strøm & Slettan, Audun (2022). Great crested newt Triturus cristatus, smooth newt Lissotriton vulgaris, and other amphibians in an acidified area of southern Norway surveyed using eDNA and other methods. The Herpetological Bulletin. ISSN 1473-0928. 161(161), p. 5–11. doi: 10.33256/hb161.511.
• Moseid, Camilla V.S.; Falkenhaug, Tone & Slettan, Audun (2021). Development of a TaqMan PCR assay for the identification of the non-native copepod Acartia tonsa, and detection of this species in Norwegian coastal waters. Journal of Plankton Research. ISSN 0142-7873. 43(3), p. 497–499. doi: 10.1093/plankt/fbab029.
• Kjær, Lene Jung; Klitgaard, Kristine; Soleng, Arnulf; Edgar, Kristin Skarsfjord; Lindstedt, Heidi Elisabeth Heggen & Paulsen, Katrine Mørk [Show all 17 contributors for this article] (2020). Spatial data of Ixodes ricinus instar abundance and nymph pathogen prevalence, Scandinavia, 2016–2017. Scientific Data. ISSN 2052-4463. 7. doi: 10.1038/s41597-020-00579-y. Full text in Research Archive Show summary

  Ticks carry pathogens that can cause disease in both animals and humans, and there is a need to monitor the distribution and abundance of ticks and the pathogens they carry to pinpoint potential high risk areas for tick-borne disease transmission. In a joint Scandinavian study, we measured Ixodes ricinus instar abundance at 159 sites in southern Scandinavia in August-September, 2016, and collected 29,440 tick nymphs at 50 of these sites. We additionally measured abundance at 30 sites in August-September, 2017. We tested the 29,440 tick nymphs in pools of 10 in a Fluidigm real-time PCR chip to screen for 17 different tick-associated pathogens, 2 pathogen groups and 3 tick species. We present data on the geolocation, habitat type and instar abundance of the surveyed sites, as well as presence/absence of each pathogen in all analysed pools from the 50 collection sites and individual prevalence for each site. These data can be used alone or in combination with other data for predictive modelling and mapping of high-risk areas.

• Kjær, Lene Jung; Klitgaard, Kirstine; Soleng, Arnulf; Edgar, Kristin Skarsfjord; Lindstedt, Heidi Elisabeth Heggen & Paulsen, Katrine Mørk [Show all 17 contributors for this article] (2020). Spatial patterns of pathogen prevalence in questing Ixodes ricinus nymphs in southern Scandinavia, 2016. Scientific Reports. ISSN 2045-2322. 10, p. 1–14. doi: 10.1038/s41598-020-76334-5. Full text in Research Archive
• Halvorsen, Silje; Korslund, Lars; Gustavsen, Per Øyvind & Slettan, Audun (2020). Environmental DNA analysis indicates that migration barriers are decreasing the occurrence of European eel (Anguilla anguilla) in distance from the sea. Global Ecology and Conservation. ISSN 2351-9894. 24. doi: 10.1016/j.gecco.2020.e01245. Full text in Research Archive
• Jung Kjær, Lene; Soleng, Arnulf; Edgar, Kristin Skarsfjord; Lindstedt, Heidi Elisabeth Heggen; Paulsen, Katrine Mørk & Andreassen, Åshild Kristine [Show all 16 contributors for this article] (2019). Predicting the spatial abundance of Ixodes ricinus ticks in southern Scandinavia using environmental and climatic data. Scientific Reports. ISSN 2045-2322. 9(1). doi: 10.1038/s41598-019-54496-1. Full text in Research Archive Show summary

  Recently, focus on tick-borne diseases has increased as ticks and their pathogens have become widespread and represent a health problem in Europe. Understanding the epidemiology of tick-borne infections requires the ability to predict and map tick abundance. We measured Ixodes ricinus abundance at 159 sites in southern Scandinavia from August-September, 2016. We used field data and environmental variables to develop predictive abundance models using machine learning algorithms, and also tested these models on 2017 data. Larva and nymph abundance models had relatively high predictive power (normalized RMSE from 0.65–0.69, R2 from 0.52–0.58) whereas adult tick models performed poorly (normalized RMSE from 0.94–0.96, R2 from 0.04–0.10). Testing the models on 2017 data produced good results with normalized RMSE values from 0.59–1.13 and R2 from 0.18–0.69. The resulting 2016 maps corresponded well with known tick abundance and distribution in Scandinavia. The models were highly influenced by temperature and vegetation, indicating that climate may be an important driver of I. ricinus distribution and abundance in Scandinavia. Despite varying results, the models predicted abundance in 2017 with high accuracy. The models are a first step towards environmentally driven tick abundance models that can assist in determining risk areas and interpreting human incidence data.

• Kjær, Lene Jung; Soleng, Arnulf; Edgar, Kristin Skarsfjord; Lindstedt, Heidi Elisabeth H.; Paulsen, Katrine Mørk & Andreassen, Åshild Kristine [Show all 16 contributors for this article] (2019). Predicting and mapping human risk of exposure to ixodes ricinus nymphs using climatic and environmental data, Denmark, Norway and Sweden, 2016. Eurosurveillance. ISSN 1025-496X. 24(9). doi: 10.2807/1560-7917.ES.2019.24.9.1800101. Full text in Research Archive
• Tariq, Ambreen; Mansoor, Mohammad Azam; Marti, Hans-Peter; Jonsson, Grete; Slettan, Audun & Weeraman, Pabasara [Show all 7 contributors for this article] (2018). Systemic redox biomarkers and their relationship to prognostic risk markers in autosomal dominant polycystic kidney disease and IgA nephropathy. Clinical Biochemistry. ISSN 0009-9120. 56, p. 33–40. doi: 10.1016/j.clinbiochem.2018.04.010.
• Kjelland, Vivian; Rollum, Rikke; Korslund, Lars; Slettan, Audun & Tveitnes, Dag (2015). Borrelia miyamotoi is widespread in Ixodes ricinus ticks in southern Norway. Ticks and Tick-borne Diseases. ISSN 1877-959X. 6(4), p. 516–521. doi: 10.1016/j.ttbdis.2015.04.004.
• Cabo, Rona; Hernes, Sigrunn; Slettan, Audun; Haugen, Margaretha; Ye, Shu & Blomhoff, Rune [Show all 7 contributors for this article] (2015). Effect of genetic polymorphisms involved in folate metabolism on the concentration of serum folate and plasma total homocysteine (p-tHcy) in healthy subjects after short-term folic acid supplementation: a randomized, double blind, crossover study. Genes & Nutrition. ISSN 1555-8932. 10. doi: 10.1007/s12263-015-0456-4. Full text in Research Archive
• Cabo, Rona; Hernes, Sigrunn; Slettan, Audun; Haugen, Margaretha; Ye, Shu & Blomhoff, Rune [Show all 7 contributors for this article] (2015). Effects of polymorphisms in endothelial nitric oxide synthase and folate metabolizing genes on the concentration of serum nitrate, folate, and plasma total homocysteine after folic acid supplementation: A double-blind crossover study. Nutrition - The International Journal of Applied and Basic Nutritional Sciences. ISSN 0899-9007. 31(2), p. 337–344. doi: 10.1016/j.nut.2014.08.009.
• Cabo, Rona; Kozik, Karolina; Milanowski, Maciej; Hernes, Sigrunn; Slettan, Audun & Haugen, Margaretha [Show all 9 contributors for this article] (2014). A simple high-performance liquid chromatography (HPLC) method for the measurement of pyridoxal-5-phosphate and 4-pyridoxic acid in human plasma. Clinica Chimica Acta. ISSN 0009-8981. 433, p. 150–156. doi: 10.1016/j.cca.2014.03.003.
• Hundhausen, Thomas Eckhard; Lacsamana, Nancy; Tednes, Uraiwan & Slettan, Audun (2014). RHD-genotyping ved bruk av allel-spesifikk "Loop-mediated isothermal DNA Amplification". Bioingeniøren. ISSN 0801-6828. 49(3), p. 16–21.
• Kjelland, Vivian; Ytrehus, Bjørnar; Stuen, Snorre; Skarpaas, Tone & Slettan, Audun (2011). Prevalence of Borrelia burgdorferi in Ixodes ricinus ticks collected from moose (Alces alces) and roe deer (Capreolus capreolus) in southern Norway. Ticks and Tick-borne Diseases. ISSN 1877-959X. 2, p. 99–103. doi: 10.1016/j.ttbdis.2010.12.002. Show summary

  As part of a larger survey, ears from 18 roe deer (Capreolus capreolus) and 52 moose (Alces alces) shot in the 2 southernmost counties in Norway were collected and examined for Ixodes ricinus ticks. Seventytwo adult ticks, 595 nymphs, and 267 larvae from the roe deer, and 182 adult ticks, 433 nymphs, and 70 larvae from the moose were investigated for infection with Borrelia burgdorferi sensu lato (s.l.). The results showed the presence of B. burgdorferi s.l. DNA in 2.9% of the nymphs collected from roe deer and in 4.4% of the nymphs and 6.0% of the adults collected from moose. The spirochetes were not detected in adult ticks from roe deer, or in larvae feeding on roe deer or moose. In comparison, the mean infection prevalences in questing I. ricinus collected from the same geographical area were 0.5% infection in larvae, 24.5% in nymphs, and 26.9% in adults. The most prevalent B. burgdorferi genospecies identified in ticks collected from roe deer was B. afzelii (76.5%), followed by B. garinii (17.6%), and B. burgdorferi sensu stricto (5.9%). Only B. afzelii (76.7%) and B. garinii (23.3%) were detected in ticks collected from moose. The present study indicates a lower prevalence of B. burgdorferi infection in I. ricinus ticks feeding on roe deer and moose compared to questing ticks. This is the first study to report B. burgdorferi s.l. prevalence in ticks removed from cervids in Norway.

• Kjelland, Vivian; Ytrehus, Bjørnar; Vikøren, Turid; Stuen, Snorre; Skarpaas, Tone & Slettan, Audun (2011). Borrelia burgdorferi sensu lato detected in skin of Norwegian mountain hares (Lepus timidus) without signs of dissemination. Journal of Wildlife Diseases. ISSN 0090-3558. 47(2), p. 293–299. doi: 10.7589/0090-3558-47.2.293.
• Kjelland, Vivian; Stuen, Snorre; Skarpaas, Tone & Slettan, Audun (2010). Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected from migratory birds in Southern Norway. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 52. doi: 10.1186/1751-0147-52-59. Show summary

  Background Borrelia burgdorferi sensu lato (s.l.) are the causative agent for Lyme borreliosis (LB), the most common tick-borne disease in the northern hemisphere. Birds are considered important in the global dispersal of ticks and tick-borne pathogens through their migration. The present study is the first description of B. burgdorferi prevalence and genotypes in Ixodes ricinus ticks feeding on birds during spring and autumn migration in Norway. Methods 6538 migratory birds were captured and examined for ticks at Lista Bird Observatory during the spring and the autumn migration in 2008. 822 immature I. ricinus ticks were collected from 215 infested birds. Ticks were investigated for infection with B. burgdorferi s.l. by real-time PCR amplification of the 16S rRNA gene, and B. burgdorferi s.l. were thereafter genotyped by melting curve analysis after real-time PCR amplification of the hbb gene, or by direct sequencing of the PCR amplicon generated from the rrs (16S)-rrl (23S) intergenetic spacer. Results B. burgdorferi s.l. were detected in 4.4% of the ticks. The most prevalent B. burgdorferi genospecies identified were B. garinii (77.8%), followed by B.valaisiana (11.1%), B. afzelii (8.3%) and B. burgdorferi sensu stricto (2.8%). Conclusion Infection rate in ticks and genospecies composition were similar in spring and autumn migration, however, the prevalence of ticks on birds was higher during spring migration. The study supports the notion that birds are important in the dispersal of ticks, and that they may be partly responsible for the heterogeneous distribution of B. burgdorferi s.l. in Europe.

• Kjelland, Vivian; Stuen, Snorre; Skarpaas, Tone & Slettan, Audun (2010). Prevalence and genotypes of Borrelia burgdorferi sensu lato infection in Ixodes ricinus ticks in southern Norway. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 42(8), p. 579–585. doi: 10.3109/00365541003716526. Show summary

  From April to October 2007, host-seeking Ixodes ricinus ticks were collected from 4 locations in southern Norway: Farsund, Mandal, Sogne and Tromoy. Two hundred and ten larvae, 1130 nymphs and 449 adults were investigated for infection with Borrelia burgdorferi sensu lato (s.l.) by real-time polymerase chain reaction (PCR) amplification of the 16S rRNA gene. The total percentage of B. burgdorferi s.l. in nymphal and adult ticks was determined to be 31.3% in Farsund, 25.2% in Mandal, 22.3% in Sogne and 22.1% in Tromoy. Larvae were pooled in groups of 10 before analysis, and Borrelia infection was detected in 1 of the 21 larvae pools. B. burgdorferi s.l. were genotyped by melting curve analysis after real-time PCR amplification of the hbb gene, or by direct sequencing of the PCR amplicon generated from the rrs (16S)-rrl (23S) intergenetic spacer. The most prevalent B. burgdorferi genospecies identified were B. afzelii (61.6%), followed by B. garinii (23.4%) and B. burgdorferi sensu stricto (10.6%). B. valaisiana (4.5%) was identified in Norwegian ticks for the first time. Mixed infections were observed in 0.3% of the infected ticks. A higher prevalence of B. burgdorferi s.l. was found in the present study than what has been reported in previous Nordic studies.

• Rengmark, Aina Haugen; Rengmark, Aina Haugen; Slettan, Audun; Lee, Woo-Jai; Lie, Øystein & Lingaas, Frode [Show all 7 contributors for this article] (2007). Identification and mapping of genes associated with salt tolerance in tilapia. Journal of Fish Biology. ISSN 0022-1112. 71(SC), p. 409–422.
• Rengmark, Aina Haugen; Rengmark, Aina Haugen; Slettan, Audun; Skaala, Øystein; Lie, Øystein & Lingaas, Frode [Show all 7 contributors for this article] (2006). Genetic variability in wild and farmed Atlantic salmon (Salmo salar) strains estimated by SNP and microsatellites. Aquaculture. ISSN 0044-8486. 253, p. 229–237. Show summary

  The SNP collection showed nearly as good results as the microsatellites in this study and improved high throughput typing methods for SNP detection suggest that they can be a good alternative to microsatellites for future typing. (C) 2005 Elsevier B.V. All rights reserved.

• Lee, Bo-Young; Lee, Woo-Jai; Streelman, Todd; Carleton, Karen; Howe, Aimee & Hulata, Gideon [Show all 10 contributors for this article] (2005). A Second-Generation Genetic Linkage Map of Tilapia (Oreochromis spp.). Genetics. ISSN 0016-6731. 170, p. 237–244.
• Slettan, Audun; Gebhardt, Kirsti; Kristiansen, Evy; Birkeland, Nils Kåre & Lindqvist, Bjørn H (1992). Escherichia coli K-12 and B contain functional bacteriophage P2 ogr genes. Journal of Bacteriology. ISSN 0021-9193. 174(12), p. 4094–4100. doi: 10.1128/jb.174.12.4094-4100.1992.

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• Kjelland, Vivian; Korslund, Lars & Slettan, Audun (2014). Fakta om flått. Kagge Forlag AS. ISBN 978-82-489-1414-3. 126 p.

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• Lien, Anne; Nygård, Malene Østreng; Laugen, Ane Timenes; Lie, Asbjørn; Slettan, Audun & Johansen, Beate Strøm [Show all 33 contributors for this article] (2023). Utbygging vil ødelegge for biologisk mangfold på campus Gimlemoen. NB! 34 forfattere totalt. Fædrelandsvennen. ISSN 0805-3790. p. 19–19.
• Kjær, Lene Jung; Klitgaard, Kirstine; Soleng, Arnulf; Edgar, Kristin Skarsfjord; Lindstedt, Heidi Elisabeth Heggen & Paulsen, Katrine Mørk [Show all 17 contributors for this article] (2020). Author Correction: Spatial data of Ixodes ricinus instar abundance and nymph pathogen prevalence, Scandinavia, 2016–2017 (Scientific Data, (2020), 7, 1, (238), 10.1038/s41597-020-00579-y). Scientific Data. ISSN 2052-4463. 7(1). doi: 10.1038/s41597-020-00606-y.
• Kjær, Lene Jung; Soleng, Arnulf; Edgar, Kristin Skarsfjord; Lindstedt, Heidi Elisabeth H.; Paulsen, Katrine Mørk & Andreassen, Åshild Kristine [Show all 18 contributors for this article] (2019). A large-scale screening for the taiga tick, Ixodes persulcatus, and the meadow tick, Dermacentor reticulatus, in southern Scandinavia, 2016. Parasites & Vectors. ISSN 1756-3305. 12:338, p. 1–4. doi: 10.1186/s13071-019-3596-3.
• Slettan, Audun (2018). Flåtten overlever sprengkulda. [Newspaper]. Vesterålen.
• Slettan, Audun (2018). Flåttsommer i vente! [Internet]. Flåttbloggen.
• Slettan, Audun (2018). Mindre flått i tørken. [Newspaper]. Sunnmøringen.
• Slettan, Audun (2018). Mange flått overlevde sprengkulden – klart for ny flåttsommer. [Internet]. abc nyheter.
• Slettan, Audun (2018). Mindre flått i tørken – men mer flått nå enn før. [Newspaper]. Nationen.
• Kjelland, Vivian; Kjelland, Vivian; Korslund, Lars; Edgar, Kristin Skarsfjord; Stuen, Snorre & Slettan, Audun [Show all 9 contributors for this article] (2017). Ixodes ricinus winter survival and spring emergence in southern Norway.
• Slettan, Audun (2012). Flått og flåttbårne sykdommer, Hysteri eller trussel? In Hanisch, Thor Einar (Eds.), Agder Vitenskapsakademi. Årbok 2011. Portal forlag. ISSN 978-82-92712-69-6. p. 76–81.
• Cabo, Rona Natalie; Hernes, Sigrunn; Slettan, Audun; Haugen, H; Ye, S & Blomhoff, Rune [Show all 8 contributors for this article] (2011). Effect of polymorphisms in genes coding for enzyme involved in folate metabolism on the concentration of serum folate in healthy subjects during folic acid supplementation.
• Slettan, Audun (2009). Om bruk av flåttdrepende midler i klær.
• Slettan, Audun (2009). Om studier av flåtten og smitterisiko med borrelia og TBE. Show summary

  Også vist nasjonalt i "NRK Norge i Dag". Studier av flåtten og smitterisiko med borrelia og TBE

• Slettan, Audun (2009). Om flått og dens smitterisiko av borrelia.
• Slettan, Audun (2009). Flått og flåttbårne sykdommer.
• Slettan, Audun (2008). Flåttforskning og sykdommer -. Show summary

  Intervju med NRK Sørlandssendingen ang. utbredelse av flått på sørlandet samt faren for smitte av diverse flåttbårne sykdommer. TV-team var til stede, og intervjuet ble i tillegg til radioreportasje vist både på NRK Sørlandssendingen samt riksdekkende TV "Norge i dag" samme dag. Usikker på dato.

• Lie, Øystein & Slettan, Audun (2004). "Gamle" gener gir ny giv. ?. p. 20–23.
• Haraldstad, Tormod; Neset, Philip Thomassen; Johansen, Kurt; Slettan, Audun & Sodeland, Marte (2021). Naturlig reetablering av laks i kystvassdrag mellom Otra og Mandalselva dokumentert ved elektrofiske og analyse av miljøDNA. Norsk institutt for vannforskning. ISSN 978-82-577-7407-3. Full text in Research Archive Show summary

  I denne studien har vi dokumentert at laksen er tilbake i mange av kystvassdragene i Agder, og med dagens lave bestandssituasjon er slike reetableringer viktige. Bestandene i kystvassdragene er likevel sårbare, med få individer og små bekkesystemer. Mindre påvirkninger i nedbørfeltet og innblanding av rømt oppdrettslaks kan ha store konsekvenser for bestandene. Forsuringssituasjonen er generelt bedre i regionen og er antagelig bakgrunnen for at laksen igjen etablerer seg gjennom innvandring av laks fra de kalkede naboelvene. Vannkjemien er likevel begrensende for laksen i flere vassdrag i dag. Vi anbefaler at flere kystvassdrag kartlegges slik at vi får en oversikt over andelen laks i disse og hva som er styrende for forholdet mellom ungfisk av laks og aure i mindre vannsystemer. MiljøDNA kan være en viktig metode i en tidlig og bred screening, men tetthetsestimater og forholdet mellom artene bør foretas basert på tradisjonelt elektrofiske. Vi anbefaler at vannkjemien overvåkes i vassdrag med høyt innslag av laks, og at dosererkalking fra mindre anlegg bør vurderes.

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