{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,11]],"date-time":"2026-05-11T19:33:17Z","timestamp":1778527997222,"version":"3.51.4"},"reference-count":49,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,11,5]],"date-time":"2025-11-05T00:00:00Z","timestamp":1762300800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003407","name":"Italian Ministry of Education","doi-asserted-by":"crossref","award":["59576"],"award-info":[{"award-number":["59576"]}],"id":[{"id":"10.13039\/501100003407","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background\/Objectives: The rise in multidrug-resistant pathogens such as Pseudomonas aeruginosa (PA), coupled with declining antibiotic development, underscores the need for innovative therapeutic strategies. Repurposing approved drugs provides advantages of safety and rapid development. Since quorum sensing (QS) controls key virulence traits in PA, targeting this pathway represents a promising antivirulence approach. This study aimed to identify and repurpose existing drugs as QS inhibitors. Methods: An in silico docking screen of 3000 FDA-approved or clinically tested compounds was performed against the C4-HSL receptor RhlR. Seventeen candidates were tested in the laboratory strain PAO1 for lactone-dependent signaling inhibition. The most active compound, MK-8245, was further evaluated for effects on growth, cytotoxicity, lactone release, biofilm formation, pyocyanin, elastase, rhamnolipids, and swarming motility. Its activity was also assessed in 20 clinical PA isolates. Results: MK-8245 (40 \u00b5M) reduced QS-regulated gene expression by ~60% without affecting viability. In PAO1, it inhibited rhamnolipids (60%), pyocyanin (40%), elastase (25%), biofilm formation, and swarming motility (25%). MK-8245 also enhanced the efficacy of imipenem against biofilms. In clinical isolates, it consistently decreased lactone release (~60%), pyocyanin (~50%), rhamnolipids (~40%), biofilm formation (~30%), and swarming motility (~25%). Conclusions: MK-8245 emerges as a promising antivirulence candidate against P. aeruginosa. By disrupting QS signaling and impairing multiple virulence factors, it attenuates pathogenicity without bactericidal pressure. Its synergy with standard antibiotics and consistent activity in clinical isolates highlight its translational potential and warrant further preclinical evaluation.<\/jats:p>","DOI":"10.3390\/antibiotics14111116","type":"journal-article","created":{"date-parts":[[2025,11,5]],"date-time":"2025-11-05T16:09:47Z","timestamp":1762358987000},"page":"1116","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Repurposing MK-8245 as a Quorum Sensing Inhibitor to Suppress Virulence and Potentiate Antibiotic Activity in Pseudomonas aeruginosa"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5564-7010","authenticated-orcid":false,"given":"Giulia","family":"Bernab\u00e8","sequence":"first","affiliation":[{"name":"Department of Molecular Medicine, University of Padua, 35121 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giovanni","family":"Marzaro","sequence":"additional","affiliation":[{"name":"Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-3594-2561","authenticated-orcid":false,"given":"Mahmoud Elsayed Mosaad","family":"Shalata","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine, University of Padua, 35121 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniela","family":"Iosob","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine, University of Padua, 35121 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Valentina","family":"Inglima","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine, University of Padua, 35121 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7428-0656","authenticated-orcid":false,"given":"Massimo","family":"Bellato","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Padua, 35131 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ignazio","family":"Castagliuolo","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine, University of Padua, 35121 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3279-9000","authenticated-orcid":false,"given":"Paola","family":"Brun","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine, University of Padua, 35121 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Lee, J.H., Kim, N.-H., Jang, K.-M., Jin, H., Shin, K., Jeong, B.C., Kim, D.-W., and Lee, S.H. (2023). Prioritization of Critical Factors for Surveillance of the Dissemination of Antibiotic Resistance in Pseudomonas aeruginosa: A Systematic Review. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms242015209"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Reig, S., Le Gouellec, A., and Bleves, S. (2022). What Is New in the Anti-Pseudomonas aeruginosa Clinical Development Pipeline Since the 2017 WHO Alert?. Front. Cell. Infect. Microbiol., 12.","DOI":"10.3389\/fcimb.2022.909731"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1016\/j.tim.2011.04.005","article-title":"Pseudomonas aeruginosa: All roads lead to resistance","volume":"19","author":"Breidenstein","year":"2011","journal-title":"Trends Microbiol."},{"key":"ref_4","unstructured":"World Health Organization (2024). WHO Bacterial Priority Pathogens List, 2024-Bacterial Pathogens of Public Health Importance to Guide Research, Development and Strategies to Prevent and Control Antimicrobial Resistance, World Health Organization. Available online: https:\/\/www.who.int\/publications\/i\/item\/9789240093461."},{"key":"ref_5","unstructured":"ECDC (2023). Antimicrobial Resistance Surveillance in Europe, ECDC."},{"key":"ref_6","unstructured":"Iacchini, S., Boros, S., Pezzotti, P., Caramia, A., Errico, G., Del Grosso, M., Camilli, R., Giufr\u00e8, M., Pantosti, A., and Maraglino, F. (2025, October 07). AR-ISS: Sorveglianza nazionale dell\u2019Antibiotico-Resistenza. Dati 2023. Available online: https:\/\/www.iss.it."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1038\/s41392-022-01056-1","article-title":"Pseudomonas aeruginosa: Pathogenesis, virulence factors, antibiotic resistance, interaction with host, technology advances and emerging therapeutics","volume":"7","author":"Qin","year":"2022","journal-title":"Signal Transduct. Target. Ther."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1007\/s13238-014-0100-x","article-title":"The hierarchy quorum sensing network in Pseudomonas aeruginosa","volume":"6","author":"Lee","year":"2015","journal-title":"Protein Cell"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Trottier, M.C., de Oliveira Pereira, T., Groleau, M.C., Hoffman, L.R., Dandekar, A.A., and D\u00e9ziel, E. (2024). \u201cThe end of the reign of a master regulator\u2019\u2019? A defect in function of the LasR quorum sensing regulator is a common feature of Pseudomonas aeruginosa isolates. mBio, 15.","DOI":"10.1128\/mbio.02376-23"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"e00532-20","DOI":"10.1128\/mBio.00532-20","article-title":"RhlR-Regulated Acyl-Homoserine Lactone Quorum Sensing in a Cystic Fibrosis Isolate of Pseudomonas aeruginosa","volume":"11","author":"Cruz","year":"2020","journal-title":"mBio"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"7986","DOI":"10.1038\/s41467-023-43702-4","article-title":"Quorum-sensing synthase mutations re-calibrate autoinducer concentrations in clinical isolates of Pseudomonas aeruginosa to enhance pathogenesis","volume":"14","author":"Simanek","year":"2023","journal-title":"Nat. Commun."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"262","DOI":"10.18683\/germs.2022.1328","article-title":"Anti-virulence therapeutic strategies against bacterial infections: Recent advances","volume":"12","author":"Dehbanipour","year":"2022","journal-title":"Germs"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Wang, J., Lu, X., Wang, C., Yue, Y., Wei, B., Zhang, H., Wang, H., and Chen, J. (2024). Research Progress on the Combination of Quorum-Sensing Inhibitors and Antibiotics against Bacterial Resistance. Molecules, 29.","DOI":"10.3390\/molecules29071674"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e01296-18","DOI":"10.1128\/AAC.01296-18","article-title":"Identification of FDA-Approved Drugs as Antivirulence Agents Targeting the pqs Quorum-Sensing System of Pseudomonas aeruginosa","volume":"62","author":"Baldelli","year":"2018","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1038\/nrd.2018.168","article-title":"Drug repurposing: Progress, challenges and recommendations","volume":"18","author":"Pushpakom","year":"2019","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"107781","DOI":"10.1016\/j.micpath.2025.107781","article-title":"FDA-approved drugs for targeting virulence of Pseudomonas aeruginosa: A drug repurposing approach to combat multidrug resistance","volume":"206","author":"Sharma","year":"2025","journal-title":"Microb. Pathog."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Bernab\u00e8, G., Marzaro, G., Di Pietra, G., Otero, A., Bellato, M., Pauletto, A., Scarpa, M., Sut, S., Chilin, A., and Dall\u2019aCqua, S. (2022). A novel phenolic derivative inhibits AHL-dependent quorum sensing signaling in Pseudomonas aeruginosa. Front. Pharmacol., 13.","DOI":"10.3389\/fphar.2022.996871"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Mir\u00f3-Canturri, A., Ayerbe-Algaba, R., and Smani, Y. (2019). Drug Repurposing for the Treatment of Bacterial and Fungal Infections. Front. Microbiol., 10.","DOI":"10.3389\/fmicb.2019.00041"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"673","DOI":"10.1038\/nrd1468","article-title":"Drug repositioning: Identifying and developing new uses for existing drugs","volume":"3","author":"Ashburn","year":"2004","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Hegazy, W.A.H., Khayat, M.T., Ibrahim, T.S., Nassar, M.S., Bakhrebah, M.A., Abdulaal, W.H., Alhakamy, N.A., and Bendary, M.M. (2020). Repurposing Anti-diabetic Drugs to Cripple Quorum Sensing in Pseudomonas aeruginosa. Microorganisms, 8.","DOI":"10.3390\/microorganisms8091285"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Khayat, M.T., Abbas, H.A., Ibrahim, T.S., Elbaramawi, S.S., Khayyat, A.N., Alharbi, M., Hegazy, W.A.H., and Yehia, F.A.-Z.A. (2023). Synergistic Benefits: Exploring the Anti-Virulence Effects of Metformin\/Vildagliptin Antidiabetic Combination against Pseudomonas aeruginosa via Controlling Quorum Sensing Systems. Biomedicines, 11.","DOI":"10.3390\/biomedicines11051442"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Khayat, M.T., Ibrahim, T.S., Darwish, K.M., Khayyat, A.N., Alharbi, M., Khafagy, E.-S., Ali, M.A.M., Hegazy, W.A.H., and Abbas, H.A. (2022). Hiring of the Anti-Quorum Sensing Activities of Hypoglycemic Agent Linagliptin to Alleviate the Pseudomonas aeruginosa Pathogenesis. Microorganisms, 10.","DOI":"10.3390\/microorganisms10122455"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Lim, T., Ham, S.-Y., Nam, S., Kim, M., Lee, K.Y., Park, H.-D., and Byun, Y. (2022). Recent Advance in Small Molecules Targeting RhlR of Pseudomonas aeruginosa. Antibiotics, 11.","DOI":"10.3390\/antibiotics11020274"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"576","DOI":"10.1038\/nrmicro.2016.89","article-title":"Quorum sensing signal-response systems in Gram-negative bacteria","volume":"14","author":"Papenfort","year":"2016","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"6840","DOI":"10.1128\/AEM.02378-13","article-title":"Resistance to quorum-quenching compounds","volume":"79","author":"Maeda","year":"2013","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1093\/femsre\/fux010","article-title":"Molecular mechanisms of biofilm-based antibiotic resistance and tolerance in pathogenic bacteria","volume":"41","author":"Hall","year":"2017","journal-title":"FEMS Microbiol. Rev."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Moradali, M.F., Ghods, S., and Rehm, B.H.A. (2017). Pseudomonas aeruginosa Lifestyle: A Paradigm for Adaptation, Survival, and Persistence. Front. Cell. Infect. Microbiol., 7.","DOI":"10.3389\/fcimb.2017.00039"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5","DOI":"10.2174\/1381612820666140905114627","article-title":"Quorum sensing inhibitors as anti-biofilm agents","volume":"21","author":"Brackman","year":"2015","journal-title":"Curr. Pharm. Des."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1080\/21505594.2020.1770508","article-title":"Identification of FDA-approved antivirulence drugs targeting the Pseudomonas aeruginosa quorum sensing effector protein PqsE","volume":"11","author":"Baldelli","year":"2020","journal-title":"Virulence"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"e02039-23","DOI":"10.1128\/mbio.02039-23","article-title":"RsaL-driven negative regulation promotes heterogeneity in Pseudomonas aeruginosa quorum sensing","volume":"14","author":"Mellini","year":"2023","journal-title":"mBio"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e0011322","DOI":"10.1128\/msystems.00113-22","article-title":"Genetic and Transcriptomic Characteristics of RhlR-Dependent Quorum Sensing in Cystic Fibrosis Isolates of Pseudomonas aeruginosa","volume":"7","author":"KAsfahl","year":"2022","journal-title":"mSystems"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"e01513-16","DOI":"10.1128\/mBio.01513-16","article-title":"LasR Variant Cystic Fibrosis Isolates Reveal an Adaptable Quorum-Sensing Hierarchy in Pseudomonas aeruginosa","volume":"7","author":"Feltner","year":"2016","journal-title":"mBio"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"862","DOI":"10.1080\/21505594.2020.1787034","article-title":"Differential adaptability between reference strains and clinical isolates of Pseudomonas aeruginosa into the lung epithelium intracellular lifestyle","volume":"11","author":"Torrents","year":"2020","journal-title":"Virulence"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Islam, O.K., Islam, I., Saha, O., Rahaman, M., Sultana, M., Bockm\u00fchl, D.P., and Hossain, M.A. (2023). Genomic variability correlates with biofilm phenotypes in multidrug resistant clinical isolates of Pseudomonas aeruginosa. Sci. Rep., 13.","DOI":"10.1038\/s41598-023-35056-0"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Duplantier, M., Lohou, E., and Sonnet, P. (2021). Quorum Sensing Inhibitors to Quench P. aeruginosa Pathogenicity. Pharmaceuticals, 14.","DOI":"10.3390\/ph14121262"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Touati, A., Ibrahim, N.A., Tighilt, L., and Idres, T. (2025). Anti-QS Strategies Against Pseudomonas aeruginosa Infections. Microorganisms, 13.","DOI":"10.3390\/microorganisms13081838"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Simanek, K.A., Paczkowski, J.E., Hardouin, J., Simanek, K.A., and Paczkowski, J.E. (2022). Resistance Is Not Futile: The Role of Quorum Sensing Plasticity in Pseudomonas aeruginosa Infections and Its Link to Intrinsic Mechanisms of Antibiotic Resistance. Microorganisms, 10.","DOI":"10.3390\/microorganisms10061247"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1021\/bk-2019-1323.ch001","article-title":"Quorum Sensing in Pseudomonas aeruginosa and Its Relationship to Biofilm Development","volume":"1323","author":"Lin","year":"2019","journal-title":"ACS Symp. Ser."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"e00932-15","DOI":"10.1128\/genomeA.00932-15","article-title":"First complete genome sequence of Pseudomonas aeruginosa (Schroeter 1872) Migula 1900 (DSM 50071T), determined using PacBio single-molecule real-time technology","volume":"3","author":"Nakano","year":"2015","journal-title":"Genome Announc."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"6902","DOI":"10.1128\/JB.186.20.6902-6914.2004","article-title":"Three Parallel Quorum-Sensing Systems Regulate Gene Expression in Vibrio harveyi","volume":"186","author":"Henke","year":"2004","journal-title":"J. Bacteriol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1046\/j.1365-2958.1999.01208.x","article-title":"A genetic analysis of the function of LuxO, a two-component response regulator involved in quorum sensing in Vibrio harveyi","volume":"31","author":"Freeman","year":"1999","journal-title":"Mol. Microbiol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1007\/s00216-006-0824-4","article-title":"Analysing traces of autoinducer-2 requires standardization of the Vibrio harveyi bioassay","volume":"387","author":"Vilchez","year":"2007","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3891","DOI":"10.1021\/acs.jcim.1c00203","article-title":"AutoDock Vina 1.2.0: New Docking Methods, Expanded Force Field, and Python Bindings","volume":"61","author":"Eberhardt","year":"2021","journal-title":"J. Chem. Inf. Model."},{"key":"ref_44","first-page":"137","article-title":"Chapter 5 Whole-Cell Biosensors for Qualitative and Quantitative Analysis of Quorum Sensing Signal Molecules and the Investigation of Quorum Quenching Agents","volume":"64","author":"Mellini","year":"2008","journal-title":"Adv. Appl. Microbiol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1080\/21505594.2015.1135289","article-title":"Galleria mellonella infection models for the study of bacterial diseases and for antimicrobial drug testing","volume":"7","author":"Tsai","year":"2016","journal-title":"Virulence"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"106281","DOI":"10.1016\/j.micpath.2023.106281","article-title":"Anti-virulence prospects of Metformin against Pseudomonas aeruginosa: A new dimension to a multifaceted drug","volume":"183","author":"Chadha","year":"2023","journal-title":"Microb. Pathog."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"808","DOI":"10.4314\/ahs.v17i3.24","article-title":"Repurposing metformin as a quorum sensing inhibitor in Pseudomonas aeruginosa","volume":"17","author":"Abbas","year":"2017","journal-title":"Afr. Health Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"698","DOI":"10.1016\/j.apjtb.2016.06.008","article-title":"Phenolic compounds affect production of pyocyanin, swarming motility and biofilm formation of Pseudomonas aeruginosa","volume":"6","author":"Ugurlu","year":"2016","journal-title":"Asian Pac. J. Trop. Biomed."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Rasamiravaka, T., Vandeputte, O., and Jaziri, M. (2016). Procedure for Rhamnolipids Quantification Using Methylene-blue. Bio-Protocol, 6.","DOI":"10.21769\/BioProtoc.1783"}],"container-title":["Antibiotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/11\/1116\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,7]],"date-time":"2025-11-07T05:15:55Z","timestamp":1762492555000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/11\/1116"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,5]]},"references-count":49,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["antibiotics14111116"],"URL":"https:\/\/doi.org\/10.3390\/antibiotics14111116","relation":{},"ISSN":["2079-6382"],"issn-type":[{"value":"2079-6382","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,5]]}}}