No picture, placeholder image
No picture, placeholder image
Professor Farmasiija instituhtta orjan.samuelsen@uit.no Tromsø

Ørjan Samuelsen



  • Marit Hetland, Mia Angelique Winkler, Håkon Kaspersen, Fredrik Håkonsholm, Ragna-Johanne Bakksjø, Eva Bernhoff et al.:
    A genome-wide One Health study of Klebsiella pneumoniae in Norway reveals overlapping populations but few recent transmission events across reservoirs
    Genome Medicine 28. Apr 2025 DOI
  • Astri Lervik Larsen, Torunn Annie Pedersen, Arnfinn Sundsfjord, Theodor Anton Ross, Anja Guleng, Jon Birger Haug et al.:
    Hospital toilets and drainage systems as a reservoir for a long-term polyclonal outbreak of clinical infections with multidrug-resistant Klebsiella oxytoca species complex
    Infection Prevention in Practice (IPIP) 2025 DOI
  • Bjørg Haldorsen, Ørjan Samuelsen, Jessin Janice, Miriam Sare, Mari Molvik, Arnfinn Sundsfjord et al.:
    Import of global high-risk clones is the primary driver of carbapenemase-producing Pseudomonas aeruginosa in Norway
    Journal of Medical Microbiology 2025 DOI
  • Sergio Arredondo Alonso, Anna Kaarina Pöntinen, João Alves Gama, Rebecca Ashley Gladstone, Klaus Harms, Gerry Tonkin-Hill et al.:
    Plasmid-driven strategies for clone success in Escherichia coli
    Nature Communications 03. Apr 2025 DOI / FULLTEKST
  • Marit Hetland, Mia Angelique Winkler, Håkon Kaspersen, Fredrik Håkonsholm, Ragna-Johanne Bakksjø, Eva Bernhoff et al.:
    Complete genomes of 568 diverse Klebsiella pneumoniae species complex isolates from humans, animals, and marine sources in Norway from 2001 to 2020
    Microbiology Resource Announcements (MRA) 2025 DOI
  • Anna Kaarina Pöntinen, Rebecca Ashley Gladstone, Henri Pesonen, Maiju Pesonen, Francois Pierre Alexandre Cleon, Benjamin J Parcell et al.:
    Modulation of multidrug-resistant clone success in Escherichia coli populations: a longitudinal, multi-country, genomic and antibiotic usage cohort study
    Lancet Microbe 2024 DOI / ARKIV
  • Sandra Witteveen, Jörg B Hans, Radosław Izdebski, Henrik Hasman, Ørjan Samuelsen, Laurent Dortet et al.:
    Dissemination of extensively drug-resistant NDM-producing Providencia stuartii in Europe linked to patients transferred from Ukraine, March 2022 to March 2023
    Eurosurveillance 2024 DOI / ARKIV
  • Anke Kohlenberg, Olov Svartström, Petra Apfalter, Rainer Hartl, Pierre Bogaerts, Te-Din Huang et al.:
    Emergence of Escherichia coli ST131 carrying carbapenemase genes, European Union/European Economic Area, August 2012 to May 2024
    Eurosurveillance 2024 DOI
  • Kara K. Tsang, Margaret M C Lam, Ryan R. Wick, Kelly L. Wyres, Michael Bachman, Stephen Baker et al.:
    Diversity, functional classification and genotyping of SHV β-lactamases in Klebsiella pneumoniae
    Microbial Genomics 2024 DOI / ARKIV
  • Tamim Khawaja, Tommi Mäklin, Teemu Kallonen, Rebecca Ashley Gladstone, Anna Kaarina Pöntinen, Sointu Mero et al.:
    Deep sequencing of Escherichia coli exposes colonisation diversity and impact of antibiotics in Punjab, Pakistan
    Nature Communications 2024 DOI / ARKIV
  • Aasmund Fostervold, Niclas Peter Raffelsberger, Marit Hetland, Ragna-Johanne Bakksjø, Eva Bernhoff, Ørjan Samuelsen et al.:
    Risk of death in Klebsiella pneumoniae bloodstream infections is associated with specific phylogenetic lineages
    Journal of Infection 2024 DOI / ARKIV
  • Sergio Arredondo Alonso, Rebecca Ashley Gladstone, Anna Kaarina Pöntinen, João Alves Gama, Anita C. Schürch, Val F. Lanza et al.:
    Mge-cluster: a reference-free approach for typing bacterial plasmids
    NAR Genomics and Bioinformatics 2023 DOI / ARKIV
  • Jessica Kate Calland, Kaisa Haukka, Stephen W Kpordze, Atanyiwoen Brusah, Marta Corbella, Cristina Merla et al.:
    Population structure and antimicrobial resistance among Klebsiella isolates sampled from human, animal, and environmental sources in Ghana: a cross-sectional genomic One Health study
    Lancet Microbe 2023 DOI / ARKIV
  • Marius Linkevicius, Rémy A Bonnin, Erik Alm, Olov Svartström, Petra Apfalter, Rainer Hartl et al.:
    Rapid cross-border emergence of NDM-5-producing Escherichia coli in the European Union/European Economic Area, 2012 to June 2022
    Eurosurveillance 2023 DOI / ARKIV
  • Niclas Peter Raffelsberger, Dorota Julia Buczek, Kristian Svendsen, Lars Småbrekke, Anna Kaarina Pöntinen, Iren Høyland Löhr et al.:
    Community carriage of ESBL-producing Escherichia coli and Klebsiella pneumoniae: a cross-sectional study of risk factors and comparative genomics of carriage and clinical isolates
    mSphere 2023 DOI / ARKIV
  • Oskar Ljungquist, Bjørg Haldorsen, Anna Kaarina Pöntinen, Jessin Janice, Ellen Haldis Josefsen, Petter Elstrøm et al.:
    Nationwide, population-based observational study of the molecular epidemiology and temporal trend of carbapenemase-producing Enterobacterales in Norway, 2015 to 2021
    Eurosurveillance 06. Jul 2023 DOI / ARKIV / FULLTEKST
  • Greta Petazzoni, Greta Bellinzona, Cristina Merla, Marta Corbella, Vincenzina Monzillo, Ørjan Samuelsen et al.:
    The COVID-19 Pandemic Sparked off a Large-Scale Outbreak of Carbapenem-Resistant Acinetobacter baumannii from the Endemic Strains at an Italian Hospital
    Microbiology spectrum 2023 DOI / ARKIV
  • Sergio Arredondo Alonso, George Blundell-Hunter, Zuyi Fu, Rebecca Ashley Gladstone, Alfred Fillol-Salom, Jessica Loraine et al.:
    Evolutionary and functional history of the Escherichia coli K1 capsule
    Nature Communications 2023 DOI / ARKIV
  • Paul Christoffer Lindemann, Torunn Pedersen, Dorthea Hagen Oma, Jessin Janice, Fredrik Grøvan, Ghantous Milad Chedid et al.:
    Intraregional hospital outbreak of OXA-244-producing Escherichia coli ST38 in Norway, 2020
    Eurosurveillance 2023 DOI / ARKIV
  • Pete Kinross, Carlo Gagliotti, Hanna Merk, Diamantis Plachouras, Dominique L. Monnet, Liselotte Diaz Högberg et al.:
    Large increase in bloodstream infections with carbapenem-resistant Acinetobacter species during the first 2 years of the COVID-19 pandemic, EU/EEA, 2020 and 2021
    Eurosurveillance 2022 DOI
  • Tommi Mäklin, Harry Arthur Frank Wright Thorpe, Anna Kaarina Pöntinen, Rebecca Ashley Gladstone, Yan Shao, Maiju Pesonen et al.:
    Strong pathogen competition in neonatal gut colonisation
    Nature Communications 2022 DOI / ARKIV
  • Kenneth Lindstedt, Dorota Julia Buczek, Torunn Annie Pedersen, Erik Hjerde, Niclas Peter Raffelsberger, Yutaka Suzuki et al.:
    Detection of Klebsiella pneumoniae human gut carriage: a comparison of culture, qPCR, and whole metagenomic sequencing methods
    Gut microbes 31. Aug 2022 DOI / ARKIV
  • Aleksandra Jakovljev, Jan Egil Afset, Kjersti Haugum, Harald Otto Steinum, Torunn Gresdal Rønning, Ørjan Samuelsen et al.:
    Phenotypic and genotypic characterisation of thymine auxotrophy in Escherichia coli isolated from a patient with recurrent bloodstream infection
    PLOS ONE 2022 DOI / ARKIV
  • Vidar Sørum, Emma Lu Øynes, Anna Sollied Møller, Klaus Harms, Ørjan Samuelsen, Nicole L. Podnecky et al.:
    Evolutionary Instability of Collateral Susceptibility Networks in Ciprofloxacin-Resistant Clinical Escherichia coli Strains
    mBio 2022 DOI / ARKIV
  • Supathep Tansirichaiya, Richard N. Goodman, Xinyu Guo, Issra Bulgasim, Ørjan Samuelsen, Mohammed Al-Haroni et al.:
    Intracellular Transposition and Capture of Mobile Genetic Elements following Intercellular Conjugation of Multidrug Resistance Conjugative Plasmids from Clinical Enterobacteriaceae Isolates
    Microbiology spectrum 2021 DOI / ARKIV
  • Jessin Janice, Nicholas Agyepong, Alex Owusu-Ofori, Usha Govinden, Sabiha Essack, Ørjan Samuelsen et al.:
    Carbapenem resistance determinants acquired through novel chromosomal integrations in extensively drug-resistant pseudomonas aeruginosa
    Antimicrobial Agents and Chemotherapy 2021 DOI / ARKIV
  • Rebecca Ashley Gladstone, Alan McNally, Anna Kaarina Pöntinen, Gerry Tonkin-Hill, John A. Lees, Kusti Onni Skytén et al.:
    Emergence and dissemination of antimicrobial resistance in Escherichia coli causing bloodstream infections in Norway in 2002–17: a nationwide, longitudinal, microbial population genomic study
    Lancet Microbe 29. Jun 2021 DOI / ARKIV / FULLTEKST
  • Niclas Peter Raffelsberger, Marit Andrea Klokkhammer Hetland, Kristian Svendsen, Lars Småbrekke, Iren Høyland Löhr, Lotte Andreassen et al.:
    Gastrointestinal carriage of Klebsiella pneumoniae in a general adult population: a cross-sectional study of risk factors and bacterial genomic diversity
    Gut microbes 2021 DOI / ARKIV
  • Jonina Gudmundsdottir, Elizabeth G. Aarag Fredheim, Catharina I.M. Koumans, Joachim Hegstad, Po-Cheng Tang, Dan I. Andersson et al.:
    The chemotherapeutic drug methotrexate selects for antibiotic resistance
    EBioMedicine 2021 DOI / ARKIV
  • Tommi Mäklin, Teemu Kallonen, Jarno Alanko, Ørjan Samuelsen, Kristin Hegstad, Veli Mäkinen et al.:
    Bacterial genomic epidemiology with mixed samples
    Microbial Genomics 2021 DOI / ARKIV
  • Aasmund Fostervold, Marit Andrea Klokkhammer Hetland, Ragna-Johanne Bakksjø, Eva Bernhoff, Kathryn E. Holt, Ørjan Samuelsen et al.:
    A nationwide genomic study of clinical Klebsiella pneumoniae in Norway 2001–15: introduction and spread of ESBLs facilitated by clonal groups CG15 and CG307
    Journal of Antimicrobial Chemotherapy 2021 DOI / ARKIV
  • Christopher Frøhlich, João Alves Gama, Klaus Harms, Viivi H. A. Hirvonen, Bjarte Aarmo Lund, Marc W. van der Kamp et al.:
    Cryptic β-Lactamase Evolution Is Driven by Low β-Lactam Concentrations
    mSphere 2021 DOI / ARKIV
  • Julia Kloos, João A Gama, Joachim Hegstad, Ørjan Samuelsen, Pål J Johnsen :
    Piggybacking on Niche Adaptation Improves the Maintenance of Multidrug-Resistance Plasmids
    Molecular Biology and Evolution (MBE) 2021 DOI / ARKIV
  • Sergio Arredondo Alonso, Anna Kaarina Pöntinen, Francois Pierre Alexandre Cleon, Rebecca Ashley Gladstone, Anita C. Schürch, Pål Jarle Johnsen et al.:
    A high-throughput multiplexing and selection strategy to complete bacterial genomes
    GigaScience 2021 DOI / ARKIV
  • Julia Maria Kloos, Joao Pedro Alves Gama, Pål Jarle Johnsen, Ørjan Samuelsen :
    Host dependent maintenance of a blaNDM-1-encoding plasmid in clinical Escherichia coli isolates
    Scientific Reports 2020 DOI
  • Torunn Annie Pedersen, Marit Gjerde Tellevik, Øyvind Kommedal, Paul Christoffer Lindemann, Sabrina John Moyo, Jessin Janice James Peter et al.:
    Horizontal plasmid transfer among klebsiella pneumoniae isolates is the key factor for dissemination of extended-spectrum β-lactamases among children in Tanzania
    mSphere 15. Jul 2020 DOI / ARKIV
  • Ørjan Samuelsen, Ove Alexander Høgmoen Åstrand, Christopher Frøhlich, Adam Heikal, Susann Skagseth, Trine Josefine Olsen Carlsen et al.:
    ZN148 Is a Modular Synthetic Metallo-beta-Lactamase Inhibitor That Reverses Carbapenem Resistance in Gram-Negative Pathogens In Vivo
    Antimicrobial Agents and Chemotherapy 2020 DOI / ARKIV
  • Hanna-Kirsti S. Leiros, Ane Molden Thomassen, Ørjan Samuelsen, Carl-Fredrik Flach, Stathis D. Kotsakis, Joakim Larsson :
    Structural insights into the enhanced carbapenemase efficiency of OXA-655 compared to OXA-10
    FEBS Open Bio 2020 DOI / ARKIV / FULLTEKST
  • Catherine Ludden, Felix Lötsch, Erik Alm, Narender Kumar, Karin Johansson, Barbara Albiger et al.:
    Cross-border spread of blaNDM-1- and blaOXA-48-positive Klebsiella pneumoniae: a European collaborative analysis of whole genome sequencing and epidemiological data, 2014 to 2019
    Eurosurveillance 2020 DOI / ARKIV
  • Ørjan Samuelsen, Arnfinn Sundsfjord, Miriam Sare, Ragnhild Raastad, Nina Handal :
    Karbapenem-resistente Enterobacterales i Norge: Epidemiologi, spredning og tiltak
    Folkehelseinstituttet 2025 ARKIV
  • Miriam Sare, Ørjan Samuelsen, Niclas Peter Raffelsberger, Arnfinn Ståle Sundsfjord, Iren Høyland Löhr, Aasmund Fostervold et al.:
    Risikovurdering av hypervirulente Klebsiella pneumoniae i Norge : en norsk risikovurdering av ECDC sin Rapid Risk Assessment "Emergence of hypervirulent Klebsiella pneumoniae ST23 carrying carbapenemase genes in EU/EEA countries, first update"
    Folkehelseinstituttet 2024 ARKIV
  • Marit Hetland, Mia Angelique Winkler, Thomas D Stanton, Ryan R. Wick, Margaret MC Lam, Aasmund Fostervold et al.:
    Klebsiella pneumoniae ecology and antimicrobial resistance in a One Health perspective
    2023
  • Christopher Frøhlich, Vidar Sørum, Nobuhiko Tokuriki, Ørjan Samuelsen :
    Evolution of ß-lactamase mediated cefiderocol resistance
    2022
  • Pål Jarle Johnsen, Elizabeth G Aarag Fredheim, Ørjan Samuelsen, Klaus Harms :
    The role of drugs used in cancer chemotherapy as drivers of antibiotic resistance evolution in Escherichia coli
    2022
  • Julia Maria Kloos, Lea Jänisch, Anna Kaarina Pöntinen, Ørjan Samuelsen, Pål Jarle Johnsen, Jukka Corander et al.:
    Different metabolic proficiency among dominant ExPEC lineages
    2022
  • Rebecca Ashley Gladstone, Alan McNally, Pål Jarle Johnsen, Ørjan Samuelsen, Jukka Corander :
    Antimicrobial resistance genes and clonal success in Escherichia coli isolates causing bloodstream infection – Authors’ reply
    Lancet Microbe 2021 DOI
  • Julia Maria Kloos, Joao Pedro Alves Gama, Joachim Hegstad, Ørjan Samuelsen, Pål Jarle Johnsen :
    E. coli Niche Adaptation Improves Plasmid Maintenance
    2021
  • João Alves Gama, Julia Maria Kloos, Joachim Hegstad, Ørjan Samuelsen, Pål Jarle Johnsen :
    Plasmid cost alleviation as a consequence of niche-adaptation
    2021
  • Julia Maria Kloos, João Alves Gama, Joachim Hegstad, Ørjan Samuelsen, Pål Jarle Johnsen :
    Plasmid Cost Alleviation By Hitchhiking On Niche-adaptation
    2021
  • Bjørg Haldorsen, Jessin Janice, Ørjan Samuelsen :
    Evaluation of the Amplex eazyplex® SuperBug Acineto test for detection of acquired OXA and NDM carbapenemases in Acinetobacter spp.
    Journal of Global Antimicrobial Resistance 2021 DOI

  • The 50 latest publications is shown on this page. See all publications in Cristin here →