Polyphasic characterization of a soil-derived Streptomyces sp. with activity against antimicrobial resistant Enterobacteriaceae

Polyphasic characterization of a soil-derived Streptomyces sp. with activity against antimicrobial resistant Enterobacteriaceae | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Polyphasic characterization of a soil-derived Streptomyces sp. with activity against antimicrobial resistant Enterobacteriaceae Yuri Borges Véras, Henrique Mautone Gomes, Eduardo Tarnowski Siemionko, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8991095/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The global spread of antimicrobial resistance, particularly among Gram-negative pathogens, has intensified the search for novel bioactive compounds. Actinobacteria, especially members of the genus Streptomyces, remain a prolific source of antimicrobial metabolites. In this study, soil-derived actinobacterial isolates were characterized using a polyphasic taxonomic approach combining morphological, biochemical, and molecular analyses, followed by evaluation of antimicrobial activity against multidrug-resistant Gram-negative bacteria. Among the isolates, isolate LMA17 exhibited antibacterial activity against carbapenemase-producing Klebsiella pneumoniae and a multiresistant Escherichia coli strain. Morphological characterization based on the International Streptomyces Project revealed rectiflexibiles spore chains, while biochemical assays demonstrated broad metabolic versatility. Phylogenetic analysis of the 16S rRNA gene placed LMA17 within the genus Streptomyces, showing highest similarity to Streptomyces virginiae. Culture optimization assays indicated that yeast extract supplementation might have enhanced antimicrobial production. Activity-guided extraction suggested that the bioactive compounds are predominantly polar and cationic, consistent with streptothricin-like molecules. These findings support Streptomyces sp. LMA17 as a promising source of antimicrobial agents against carbapenem-resistant Enterobacteriaceae. Actinobacteria Streptomyces Antimicrobial Resistance Carbapenemase Secondary metabolites Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementarytable1AllBiochemicaltestsperformed.xlsx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8991095","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":622063981,"identity":"acb7cb3e-6afd-43c1-8dc2-e66a488b15b5","order_by":0,"name":"Yuri Borges Véras","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA30lEQVRIiWNgGAWjYJCCAxCK+eADIMnDR4IWtmQDkBY2EizjMZMA6ySkzuBG7sMDjG02+fz9B8wqv+bYybAxMD98dAOvlnQDoJY0yxk3EtJuy25LBjqMzdg4B6+WNKBfzhw2YLjBcOy25DZmoBYeNmkitPw3kD9/sK1Ycls9sVoqDhgYHEhmY/y47TBhLZJnnjEcSKhINjC8kcYszbjtOA8bMwG/8B1PY/7wwcDOQO78+Y8ff26rtudnb374GJ8WhQNAIgHKYeYBk3iUg4B8AxKH8QcB1aNgFIyCUTAyAQBPj0fKdNIRdQAAAABJRU5ErkJggg==","orcid":"","institution":"Federal University of Rio Grande do Sul","correspondingAuthor":true,"prefix":"","firstName":"Yuri","middleName":"Borges","lastName":"Véras","suffix":""},{"id":622063982,"identity":"dd5509a4-7515-4ae2-8924-9e3bccb95b70","order_by":1,"name":"Henrique Mautone Gomes","email":"","orcid":"","institution":"Federal University of Rio Grande do Sul","correspondingAuthor":false,"prefix":"","firstName":"Henrique","middleName":"Mautone","lastName":"Gomes","suffix":""},{"id":622063983,"identity":"d1395ddc-e61c-453f-a554-fa48571c58f5","order_by":2,"name":"Eduardo Tarnowski Siemionko","email":"","orcid":"","institution":"Federal University of Rio Grande do Sul","correspondingAuthor":false,"prefix":"","firstName":"Eduardo","middleName":"Tarnowski","lastName":"Siemionko","suffix":""},{"id":622063984,"identity":"947fb6f1-87d7-4823-9c77-08f01ad973cb","order_by":3,"name":"Luiza Franco de Abreu","email":"","orcid":"","institution":"Federal University of Rio Grande do Sul","correspondingAuthor":false,"prefix":"","firstName":"Luiza","middleName":"Franco","lastName":"de Abreu","suffix":""},{"id":622063985,"identity":"af5002a4-8f9b-42c7-91bf-b53b288e3593","order_by":4,"name":"Sueli Teresinha Van der Sand","email":"","orcid":"","institution":"Federal University of Rio Grande do Sul","correspondingAuthor":false,"prefix":"","firstName":"Sueli","middleName":"Teresinha Van der","lastName":"Sand","suffix":""},{"id":622063986,"identity":"ea0c290f-829b-4a76-b706-e08c8f6470eb","order_by":5,"name":"José Cláudio Fonseca Moreira","email":"","orcid":"","institution":"Federal University of Rio Grande do Sul","correspondingAuthor":false,"prefix":"","firstName":"José","middleName":"Cláudio Fonseca","lastName":"Moreira","suffix":""}],"badges":[],"createdAt":"2026-02-27 19:09:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8991095/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8991095/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108182006,"identity":"0acd02f7-863e-417c-9130-3c4c0e8d04ac","added_by":"auto","created_at":"2026-04-30 08:59:04","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":691453,"visible":true,"origin":"","legend":"","description":"","filename":"PolyphasiccharacterizationofasoilderivedStreptomycessp.withactivityagainstantimicrobialresistantEnterobacteriaceae.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8991095/v1_covered_a403cf46-b982-4c20-bee2-845a4265aaf3.pdf"},{"id":107187404,"identity":"bc5aedb3-30e2-49a5-aa2e-b0ffcb91a0bc","added_by":"auto","created_at":"2026-04-17 19:24:58","extension":"xlsx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":8561,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarytable1AllBiochemicaltestsperformed.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-8991095/v1/70ad3cf8bd7fc61bf10e73f1.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Polyphasic characterization of a soil-derived Streptomyces sp. with activity against antimicrobial resistant Enterobacteriaceae","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Actinobacteria, Streptomyces, Antimicrobial Resistance, Carbapenemase, Secondary metabolites","lastPublishedDoi":"10.21203/rs.3.rs-8991095/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8991095/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The global spread of antimicrobial resistance, particularly among Gram-negative pathogens, has intensified the search for novel bioactive compounds. Actinobacteria, especially members of the genus Streptomyces, remain a prolific source of antimicrobial metabolites. In this study, soil-derived actinobacterial isolates were characterized using a polyphasic taxonomic approach combining morphological, biochemical, and molecular analyses, followed by evaluation of antimicrobial activity against multidrug-resistant Gram-negative bacteria. Among the isolates, isolate LMA17 exhibited antibacterial activity against carbapenemase-producing Klebsiella pneumoniae and a multiresistant Escherichia coli strain. Morphological characterization based on the International Streptomyces Project revealed rectiflexibiles spore chains, while biochemical assays demonstrated broad metabolic versatility. Phylogenetic analysis of the 16S rRNA gene placed LMA17 within the genus Streptomyces, showing highest similarity to Streptomyces virginiae. Culture optimization assays indicated that yeast extract supplementation might have enhanced antimicrobial production. Activity-guided extraction suggested that the bioactive compounds are predominantly polar and cationic, consistent with streptothricin-like molecules. These findings support Streptomyces sp. LMA17 as a promising source of antimicrobial agents against carbapenem-resistant Enterobacteriaceae.","manuscriptTitle":"Polyphasic characterization of a soil-derived Streptomyces sp. with activity against antimicrobial resistant Enterobacteriaceae","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-17 19:24:16","doi":"10.21203/rs.3.rs-8991095/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"72dd2697-5234-4dc0-afda-bd37a66cbd9a","owner":[],"postedDate":"April 17th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-04-29T10:49:47+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-29T10:55:52+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-17 19:24:16","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8991095","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8991095","identity":"rs-8991095","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}