bioRxiv preprint doi: https://doi.org/10.1101/2020.11.12.378059; this version posted June 3, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 The chemotherapeutic drug methotrexate selects for antibiotic resistance 2 3 4 Jónína S. Gudmundsdóttir1*, Elizabeth G. A. Fredheim1, Catharina I. M. Koumans2, Joachim 5 Hegstad1,3, Po-Cheng Tang4, Dan I. Andersson4, Ørjan Samuelsen1,5 and Pål J. Johnsen1* 6 7 8 1Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, 9 Tromsø, Norway. 10 2Institute of Biology, Leiden University, Leiden, The Netherlands. 11 3Research and Development Division, Department of Microbiology and Infection Control, 12 University Hospital of North Norway, Tromsø, Norway. 13 4Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, 14 Sweden. 15 5Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of 16 Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway. 17 18 19 *Correspondence to:
[email protected] or
[email protected] 20 21 22 Keywords 23 Chemotherapeutic drugs, E. coli, antibiotic resistance, methotrexate, resistance evolution bioRxiv preprint doi: https://doi.org/10.1101/2020.11.12.378059; this version posted June 3, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 24 Abstract 25 Understanding drivers of antibiotic resistance evolution is fundamental for designing optimal 26 treatment strategies and interventions to reduce the spread of antibiotic resistance.