{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T16:32:27Z","timestamp":1787157147735,"version":"build-2736575974"},"reference-count":33,"publisher":"Microbiology Society","issue":"8","license":[{"start":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T00:00:00Z","timestamp":1787097600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100005825","name":"National Institute of Food and Agriculture","doi-asserted-by":"crossref","award":["1023966"],"award-info":[{"award-number":["1023966"]}],"id":[{"id":"10.13039\/100005825","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,19]]},"abstract":"\n For the clinical treatment of infections with\n Enterobacteriaceae<\/jats:italic>\n , the development of resistance to last-resort antimicrobials like colistin is of concern, as it limits treatment options. Since 2015, ten families of\n mobile colistin resistance<\/jats:italic>\n (\n mcr<\/jats:italic>\n ) genes have been discovered; however, our understanding of MCR remains limited because (i)\n mcr-1<\/jats:italic>\n is the most studied variant, (ii)\n mcr<\/jats:italic>\n variants are rarely compared and (iii)\n mcr<\/jats:italic>\n variants are primarily studied in\n Escherichia coli<\/jats:italic>\n , even though studies have shown that\n mcr<\/jats:italic>\n variants can confer significantly different phenotypes and that lipid A (i.e. the target of colistin and\n mcr-<\/jats:italic>\n modification) structurally differs between bacterial species. To fill this gap, we examined how\n mcr-3<\/jats:italic>\n and\n mcr-9<\/jats:italic>\n , as two less frequently studied\n mcr<\/jats:italic>\n variants, impact the colistin resistance of laboratory-adapted and real-world (i.e. clinical or food) isolates of\n E. coli<\/jats:italic>\n ,\n Salmonella enterica<\/jats:italic>\n and\n Klebsiella pneumoniae<\/jats:italic>\n . We found that while\n mcr-3<\/jats:italic>\n consistently conferred colistin resistance to all tested strains,\n mcr-9<\/jats:italic>\n only conferred resistance to two strains. The fold-change in colistin minimum inhibitory concentrations was significantly impacted by both the bacterial species and the\n mcr<\/jats:italic>\n variant but not by whether a strain was a laboratory-adapted or real-world isolate. Overall, our results suggest that while laboratory-adapted strains may provide a good estimate of\n mcr<\/jats:italic>\n -mediated colistin resistance of real-world isolates, findings of\n mcr<\/jats:italic>\n -mediated phenotypes in one bacterial species should not be extrapolated to another.\n <\/jats:p>","DOI":"10.1099\/mic.0.001759","type":"journal-article","created":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T16:15:26Z","timestamp":1787156126000},"source":"Crossref","is-referenced-by-count":0,"title":["MCR-3 and MCR-9 confer species-specific increases in colistin MICs"],"prefix":"10.1099","volume":"172","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3627-9966","authenticated-orcid":false,"given":"Anna","family":"Schumann","sequence":"first","affiliation":[{"name":"Department of Food Science, Cornell University, Ithaca, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4168-5662","authenticated-orcid":false,"given":"Martin","family":"Wiedmann","sequence":"additional","affiliation":[{"name":"Department of Food Science, Cornell University, Ithaca, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"345","reference":[{"key":"R1","article-title":"Antimicrobial Resistance","year":"2023"},{"key":"R2","article-title":"Antibiotic resistance threats in the United States","year":"2019"},{"key":"R3","article-title":"Antimicrobial Resistance Threats in the United States","year":"2025"},{"key":"R4","article-title":"Federal Scientists Find in U.S. Samples the MCR-1 Gene Responsible for Colistin Resistance","year":"2022"},{"key":"R5","doi-asserted-by":"publisher","DOI":"10.3390\/microorganisms8111716"},{"key":"R6","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-020-63167-5"},{"key":"R7","doi-asserted-by":"publisher","DOI":"10.1016\/j.tim.2023.10.006"},{"key":"R8","doi-asserted-by":"publisher","DOI":"10.1128\/mmbr.00193-23"},{"key":"R9","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.65836"},{"key":"R10","doi-asserted-by":"publisher","DOI":"10.1080\/22221751.2020.1732231"},{"key":"R11","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2023.1060519"},{"key":"R12","doi-asserted-by":"publisher","DOI":"10.1128\/msphere.00731-24"},{"key":"R13","doi-asserted-by":"publisher","DOI":"10.1038\/nrmicro1068"},{"key":"R14","doi-asserted-by":"publisher","DOI":"10.1038\/s41579-019-0201-x"},{"key":"R15","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.00853-19"},{"key":"R16","doi-asserted-by":"publisher","DOI":"10.1016\/j.mimet.2025.107120"},{"key":"R17","doi-asserted-by":"publisher","DOI":"10.1128\/spectrum.00894-23"},{"key":"R18","doi-asserted-by":"publisher","DOI":"10.1128\/aem.01556-24"},{"key":"R19","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2014.00172"},{"key":"R20","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2023.1060519"},{"key":"R21","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2020.00080"},{"key":"R22","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.00853-19"},{"key":"R23","doi-asserted-by":"publisher","DOI":"10.1016\/j.tim.2004.11.001"},{"key":"R24","doi-asserted-by":"publisher","DOI":"10.1128\/jb.176.13.4144-4156.1994"},{"key":"R25","doi-asserted-by":"publisher","DOI":"10.1097\/INF.0b013e31823096a8"},{"key":"R26","article-title":"Breakpoint tables for interpretation of MICs and zone diameters Version 13.0","year":"2023"},{"key":"R27","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciaa121"},{"key":"R28","doi-asserted-by":"publisher","DOI":"10.1100\/2012\/109795"},{"key":"R29","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2020.592146"},{"key":"R30","doi-asserted-by":"publisher","DOI":"10.1111\/nyas.14244"},{"key":"R31","doi-asserted-by":"publisher","DOI":"10.1080\/22221751.2020.1754133"},{"key":"R32","doi-asserted-by":"publisher","DOI":"10.1016\/j.ebiom.2024.105326"},{"key":"R33","doi-asserted-by":"publisher","DOI":"10.1038\/nmeth765"}],"container-title":["Microbiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.microbiologyresearch.org\/content\/journal\/micro\/10.1099\/mic.0.001759?crawler=true&mimetype=application\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T16:15:26Z","timestamp":1787156126000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.microbiologyresearch.org\/content\/journal\/micro\/10.1099\/mic.0.001759"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,19]]},"references-count":33,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2026,8,19]]}},"URL":"https:\/\/doi.org\/10.1099\/mic.0.001759","relation":{},"ISSN":["1350-0872","1465-2080"],"issn-type":[{"value":"1350-0872","type":"print"},{"value":"1465-2080","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,19]]}}}