{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T05:43:16Z","timestamp":1773207796269,"version":"3.50.1"},"reference-count":14,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2020,3,18]],"date-time":"2020-03-18T00:00:00Z","timestamp":1584489600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/00211\/2020"],"award-info":[{"award-number":["UIDB\/00211\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>In this study, we report the presence of the plasmid-mediated colistin resistance (PMCR)-encoding gene mcr-1 in an Escherichia coli isolate, INSali25, recovered from lettuce produced and marketed in Portugal. Colistin MIC from the vegetable E. coli isolate\u2014determined by microdilution broth method according to EUCAST guidelines\u2014revealed a non-wild-type phenotype of colistin (MIC 16 mg\/L). To understand the genetic background of E. coli INSali25, we performed whole genome sequencing. Plasmid sequencing was also performed after plasmid DNA extraction from the transconjugant TcINSali25 (mcr-1). Directed bioinformatics analysis identified the mcr-1 gene in a 39,998 bp length contig, with an upstream region including the antibiotic resistance gene blaTEM-1 in a partial transposon Tn2, truncated by the insertion sequence IS26 and showing &gt;99% identity with previously described mcr-1-harboring IncHI2 plasmids. Further in silico analysis showed the presence of additional genes conferring resistance to \u03b2-lactams (blaTEM-1), aminoglycosides (aadA1, aph(4)-Ia, aph(6)-Id, aac(3)-Iv), macrolides (mdf(A)-type), phenicol (floR-type), tetracycline (tetA), and sulphonamides (sul2). INSali25 isolate belonged to the ST1716 lineage and showed the fimH54 and fumC27 alleles. Lettuce is a vegetable that is commonly consumed fresh and not subjected to any cooking process, which may amplify human food safety risks. Moreover, the occurrence of plasmid-mediated colistin resistance in a sample that was not imported and was acquired in a large retail store reinforces the widespread distribution of mcr-1.<\/jats:p>","DOI":"10.3390\/microorganisms8030429","type":"journal-article","created":{"date-parts":[[2020,3,19]],"date-time":"2020-03-19T03:54:14Z","timestamp":1584590054000},"page":"429","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":26,"title":["Plasmid-Mediated Colistin Resistance (mcr-1) in Escherichia coli from Non-Imported Fresh Vegetables for Human Consumption in Portugal"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7729-4199","authenticated-orcid":false,"given":"Vera","family":"Manageiro","sequence":"first","affiliation":[{"name":"National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal"},{"name":"Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4051-401 Oporto, Portugal"}]},{"given":"Daniela","family":"Jones-Dias","sequence":"additional","affiliation":[{"name":"National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal"},{"name":"Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4051-401 Oporto, Portugal"}]},{"given":"Eug\u00e9nia","family":"Ferreira","sequence":"additional","affiliation":[{"name":"National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal"}]},{"given":"Manuela","family":"Cani\u00e7a","sequence":"additional","affiliation":[{"name":"National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/S1473-3099(15)00463-6","article-title":"Colistin resistance: A major breach in our last line of defence","volume":"16","author":"Paterson","year":"2016","journal-title":"Lancet Infect. Dis."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1016\/j.cmi.2016.03.009","article-title":"Plasmid-mediated colistin resistance: An additional antibiotic resistance menace","volume":"22","author":"Nordmann","year":"2016","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"794","DOI":"10.1016\/j.tim.2018.02.006","article-title":"Towards understanding MCR-like colistin resistance","volume":"26","author":"Sun","year":"2018","journal-title":"Trends Microbiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1089\/fpd.2018.2501","article-title":"Unraveling the role of vegetables in spreading antimicrobial-resistant bacteria: A need for quantitative risk assessment","volume":"15","author":"Tetens","year":"2018","journal-title":"Foodborne Pathog. Dis."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e01139-17","DOI":"10.1128\/AAC.01139-17","article-title":"Emergence of mcr-1 in Raoultella ornithinolytica and Escherichia coli isolates from retail vegetables in China","volume":"61","author":"Luo","year":"2017","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2594","DOI":"10.1128\/AAC.00066-16","article-title":"Occurrence of the plasmid-borne mcr-1 colistin resistance gene in extended-spectrum-\u03b2-lactamase-producing Enterobacteriaceae in river water and imported vegetable samples in Switzerland","volume":"60","author":"Zurfuh","year":"2016","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.ijantimicag.2019.04.013","article-title":"Colistin-resistant mcr-positive Enterobacteriaceae in fresh vegetables, an increasing infectious threat in China","volume":"54","author":"Liu","year":"2019","journal-title":"Int. J. Antimicrob. Agents"},{"key":"ref_8","first-page":"1400","article-title":"Architecture of class 1, 2, and 3 integrons from Gram negative bacteria recovered among fruits and vegetables","volume":"7","author":"Manageiro","year":"2016","journal-title":"Front. Microbiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.ijfoodmicro.2017.10.007","article-title":"New insights into resistance to colistin and third-generation cephalosporins of Escherichia coli in poultry, Portugal: Novel blaCTX-M-166 and blaESAC genes","volume":"263","author":"Manageiro","year":"2017","journal-title":"Int. J. 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Genes (Basel), 8.","DOI":"10.3390\/genes8120394"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2385","DOI":"10.1111\/j.1462-2920.2010.02297.x","article-title":"Fresh fruit and vegetables as vehicles for the transmission of human pathogens","volume":"12","author":"Berger","year":"2010","journal-title":"Environ. Microbiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"5589","DOI":"10.1128\/AAC.00935-16","article-title":"Full-length nucleotide sequences of mcr-1-harboring plasmids isolated from extended-spectrum-\u03b2-lactamase-producing Escherichia coli isolates of different origins","volume":"60","author":"Zurfluh","year":"2016","journal-title":"Antimicrob. Agents Chemother."}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/8\/3\/429\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:07:50Z","timestamp":1760173670000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/8\/3\/429"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,3,18]]},"references-count":14,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2020,3]]}},"alternative-id":["microorganisms8030429"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms8030429","relation":{},"ISSN":["2076-2607"],"issn-type":[{"value":"2076-2607","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,3,18]]}}}