{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T06:47:12Z","timestamp":1791614832361,"version":"4.3.4"},"reference-count":73,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2017,6,14]],"date-time":"2017-06-14T00:00:00Z","timestamp":1497398400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Platostoma rotundifolium (Briq.) A. J. Paton aerial parts are widely used in Burundi traditional medicine to treat infectious diseases. In order to investigate their probable antibacterial activities, crude extracts from P. rotundifolium were assessed for their bactericidal and anti-virulence properties against an opportunistic bacterial model, Pseudomonas aeruginosa PAO1. Whereas none of the tested extracts exert bacteriostatic and\/or bactericidal proprieties, the ethyl acetate and dichloromethane extracts exhibit anti-virulence properties against Pseudomonas aeruginosa PAO1 characterized by an alteration in quorum sensing gene expression and biofilm formation without affecting bacterial viability. Bioguided fractionation of the ethyl acetate extract led to the isolation of major anti-virulence compounds that were identified from nuclear magnetic resonance and high-resolution molecular spectroscopy spectra as cassipourol, \u03b2-sitosterol and \u03b1-amyrin. Globally, cassipourol and \u03b2-sitosterol inhibit quorum sensing-regulated and -regulatory genes expression in las and rhl systems without affecting the global regulators gacA and vfr, whereas \u03b1-amyrin had no effect on the expression of these genes. These terpenoids disrupt the formation of biofilms at concentrations down to 12.5, 50 and 50 \u00b5M for cassipourol, \u03b2-sitosterol and \u03b1-amyrin, respectively. Moreover, these terpenoids reduce the production of total exopolysaccharides and promote flagella-dependent motilities (swimming and swarming). The isolated terpenoids exert a wide range of inhibition processes, suggesting a complex mechanism of action targeting P. aeruginosa virulence mechanisms which support the wide anti-infectious use of this plant species in traditional Burundian medicine.<\/jats:p>","DOI":"10.3390\/ijms18061270","type":"journal-article","created":{"date-parts":[[2017,6,14]],"date-time":"2017-06-14T10:49:53Z","timestamp":1497437393000},"page":"1270","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":38,"title":["Terpenoids from Platostoma rotundifolium (Briq.) A. J. Paton Alter the Expression of Quorum Sensing-Related Virulence Factors and the Formation of Biofilm in Pseudomonas aeruginosa PAO1"],"prefix":"10.3390","volume":"18","author":[{"given":"Tsiry","family":"Rasamiravaka","sequence":"first","affiliation":[{"name":"Laboratory of Plant Biotechnology, Universit\u00e9 Libre de Bruxelles, rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium"},{"name":"Laboratoire de Biotechnologie et Microbiologie, D\u00e9partement de Biochimie Fondamentale et Appliqu\u00e9e, Facult\u00e9 des Sciences, Universit\u00e9 d\u2019Antananarivo (UA), BP 906, Antananarivo 101, Madagascar"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8891-1137","authenticated-orcid":false,"given":"J\u00e9r\u00e9mie","family":"Ngezahayo","sequence":"additional","affiliation":[{"name":"Laboratoire de Pharmacognosie, Bromatologie et Nutrition Humaine, Facult\u00e9 de Pharmacie, Universit\u00e9 Libre de Bruxelles, CP 205\/09, Boulevard du Triomphe, 1050 Bruxelles, Belgium"},{"name":"Centre de Recherche Universitaire en Pharmacop\u00e9e et M\u00e9decine Traditionnelle (CRUPHAMET), Facult\u00e9 des Sciences, Universit\u00e9 du Burundi, BP 2700 Bujumbura, Burundi"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laurent","family":"Pottier","sequence":"additional","affiliation":[{"name":"Laboratoire de Pharmacognosie, Bromatologie et Nutrition Humaine, Facult\u00e9 de Pharmacie, Universit\u00e9 Libre de Bruxelles, CP 205\/09, Boulevard du Triomphe, 1050 Bruxelles, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sofia","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"Laboratoire de Pharmacognosie, Bromatologie et Nutrition Humaine, Facult\u00e9 de Pharmacie, Universit\u00e9 Libre de Bruxelles, CP 205\/09, Boulevard du Triomphe, 1050 Bruxelles, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Florence","family":"Souard","sequence":"additional","affiliation":[{"name":"Laboratoire de Pharmacognosie, Bromatologie et Nutrition Humaine, Facult\u00e9 de Pharmacie, Universit\u00e9 Libre de Bruxelles, CP 205\/09, Boulevard du Triomphe, 1050 Bruxelles, Belgium"},{"name":"D\u00e9partement de Pharmacochimie Mol\u00e9culaire, Universit\u00e9 Grenoble Alpes, 38000 Grenoble, France"},{"name":"D\u00e9partement de Pharmacochimie Mol\u00e9culaire, Centre National de Recherche Scientifique, 38000 Grenoble, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L\u00e9onard","family":"Hari","sequence":"additional","affiliation":[{"name":"Centre de Recherche Universitaire en Pharmacop\u00e9e et M\u00e9decine Traditionnelle (CRUPHAMET), Facult\u00e9 des Sciences, Universit\u00e9 du Burundi, BP 2700 Bujumbura, Burundi"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"St\u00e9vigny","sequence":"additional","affiliation":[{"name":"Laboratoire de Pharmacognosie, Bromatologie et Nutrition Humaine, Facult\u00e9 de Pharmacie, Universit\u00e9 Libre de Bruxelles, CP 205\/09, Boulevard du Triomphe, 1050 Bruxelles, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mondher El","family":"Jaziri","sequence":"additional","affiliation":[{"name":"Laboratory of Plant Biotechnology, Universit\u00e9 Libre de Bruxelles, rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pierre","family":"Duez","sequence":"additional","affiliation":[{"name":"Laboratoire de Pharmacognosie, Bromatologie et Nutrition Humaine, Facult\u00e9 de Pharmacie, Universit\u00e9 Libre de Bruxelles, CP 205\/09, Boulevard du Triomphe, 1050 Bruxelles, Belgium"},{"name":"Unit of Therapeutic Chemistry and Pharmacognosy, Universit\u00e9 de Mons (UMONS), B\u00e2timent VI, Chemin du Champ de Mars 25, 7000 Mons, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,6,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.cbpa.2008.01.023","article-title":"Discovery of virulence factors of pathogenic bacteria","volume":"12","author":"Wu","year":"2008","journal-title":"Curr. Opin. Chem. Biol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1111\/bcp.12356","article-title":"Targeting virulence not viability in the search for future antibacterials","volume":"79","author":"Heras","year":"2015","journal-title":"Br. J. Clin. Pharmacol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"759348:1","DOI":"10.1155\/2015\/759348","article-title":"The formation of biofilms by Pseudomonas aeruginosa: A review of the natural and synthetic compounds interfering with control mechanisms","volume":"2015","author":"Rasamiravaka","year":"2015","journal-title":"BioMed Res. Int."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Rasamiravaka, T., Vandeputte, O.M., Pottier, L., Huet, J., Rabemanantsoa, C., Kiendrebeogo, M., St\u00e9vigny, C., Duez, P., and El Jaziri, M. (2015). Pseudomonas aeruginosa biofilm formation and persistence, along with the production of quorum sensing dependent virulence factors, are disrupted by a triterpenoid coumarate ester isolated from Dalbergia trichocarpa, a tropical \u201clegume\u201d. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0132791"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1128\/CMR.00059-12","article-title":"Antimicrobial resistance and virulence: A successful or deleterious association in the bacterial world?","volume":"26","author":"Beceiro","year":"2013","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1099\/mic.0.27385-0","article-title":"Modelling protection from antimicrobial agents in biofilms through the formation of persister cells","volume":"151","author":"Roberts","year":"2005","journal-title":"Microbiology"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2606","DOI":"10.1128\/IAI.00491-13","article-title":"Biofilm formation avoids complement immunity and phagocytosis of Streptococcus pneumoniae","volume":"81","author":"Domenech","year":"2013","journal-title":"Infect. Immun."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Rutherford, S.T., and Bassler, B.L. (2012). Bacterial quorum sensing: Its role in virulence and possibilities for its control. Cold Spring Harb. Perspect. Med., 2.","DOI":"10.1101\/cshperspect.a012427"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1128\/MMBR.05007-11","article-title":"The multiple signaling systems regulating virulence in Pseudomonas aeruginosa","volume":"76","author":"Jimenez","year":"2012","journal-title":"Microbiol. Mol. Biol. Rev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3127","DOI":"10.1128\/jb.179.10.3127-3132.1997","article-title":"Regulation of las and rhl quorum sensing in Pseudomonas aeruginosa","volume":"179","author":"Pesci","year":"1997","journal-title":"J. Bacteriol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4372","DOI":"10.1128\/JB.187.13.4372-4380.2005","article-title":"Regulation of Pseudomonas quinolone signal synthesis in Pseudomonas aeruginosa","volume":"187","author":"Wade","year":"2005","journal-title":"J. Bacteriol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.chembiol.2006.11.014","article-title":"The Pseudomonas aeruginosa 4-quinolone signal molecules HHQ and PQS play multifunctional roles in quorum sensing and iron entrapment","volume":"14","author":"Diggle","year":"2007","journal-title":"Chem. Biol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1099\/00221287-148-1-87","article-title":"Inhibition of quorum sensing in Pseudomonas aeruginosa biofilm bacteria by a halogenated furanone compound","volume":"148","author":"Hentzer","year":"2002","journal-title":"Microbiology"},{"key":"ref_14","first-page":"S53","article-title":"Traditional African medicine: From ancestral know-how to bright future","volume":"350","author":"Kahumba","year":"2015","journal-title":"Science"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1016\/j.jep.2015.07.028","article-title":"Medicinal plants used by Burundian traditional healers for the treatment of microbial diseases","volume":"173","author":"Ngezahayo","year":"2015","journal-title":"J. Ethnopharmacol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1016\/j.indcrop.2016.04.004","article-title":"Plastotoma rotundifolium aerial tissue extract has antibacterial activities","volume":"86","author":"Ngezahayo","year":"2016","journal-title":"Ind. Crop. Prod."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"680","DOI":"10.1164\/rccm.201207-1160OE","article-title":"Cystic fibrosis pulmonary guidelines: Chronic medications for maintenance of lung health","volume":"187","author":"Mogayzel","year":"2013","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2120","DOI":"10.1099\/mic.0.049338-0","article-title":"The flavanone naringenin reduces the production of quorum-sensing-controlled virulence factors in Pseudomonas aeruginosa PAO1","volume":"157","author":"Vandeputte","year":"2011","journal-title":"Microbiology"},{"key":"ref_19","first-page":"1150","article-title":"Triterpenoids from Vernonia auriculifera Hiern exhibit antimicrobial activity","volume":"5","author":"Kiplimo","year":"2011","journal-title":"Afr. J. Pharm. Pharmacol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1128\/AEM.01059-09","article-title":"Identification of catechin as one of the flavonoids from Combretum albiflorum bark extract that reduces the production of quorum-sensing controlled virulence factors in Pseudomonas aeruginosa PAO1","volume":"76","author":"Vandeputte","year":"2010","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1021\/np050376w","article-title":"Cytotoxic diterpenes from Cassipourea madagascariensis from the Madagascar rainforest","volume":"69","author":"Chaturvedula","year":"2006","journal-title":"J. Nat. Prod."},{"key":"ref_22","first-page":"95","article-title":"Isolation and characterization of stigmast-5-en-3\u03b2-ol (\u03b2-sitosterol) from the leaves of Hygrophila spinosa","volume":"1","author":"Patra","year":"2010","journal-title":"IJPSR"},{"key":"ref_23","first-page":"801","article-title":"Extraction and crystal structure of \u03b2-sitosterol","volume":"33","author":"Wu","year":"2014","journal-title":"Chin. J. Struct. Chem."},{"key":"ref_24","first-page":"33","article-title":"Terpenoids and sterols from Hoya multiflora Blume","volume":"5","author":"Ebajo","year":"2015","journal-title":"J. Appl. Pharm. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1517","DOI":"10.1016\/S0031-9422(00)89569-2","article-title":"13C NMR spectra of pentacyclic triterpenoids\u2014A compilation and some salient features","volume":"37","author":"Mahato","year":"1994","journal-title":"Phytochemistry"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Rao, V. (2012). The Pentacyclic Triterpenes \u03b1, \u03b2-amyrins: A review of sources and biological activities. Phytochemicals\u2014A Global Perspective of Their Role in Nutrition and Health, InTech.","DOI":"10.5772\/1387"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1007\/s00284-016-1101-1","article-title":"Quorum sensing mechanisms and bacterial response to antibiotics in P. aeruginosa","volume":"73","author":"Rasamiravaka","year":"2016","journal-title":"Curr. Microbiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3928","DOI":"10.1128\/jb.179.12.3928-3935.1997","article-title":"Vfr controls quorum sensing in Pseudomonas aeruginosa","volume":"179","author":"Albus","year":"1997","journal-title":"J. Bacteriol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"6026","DOI":"10.1128\/JB.00409-06","article-title":"Two gacA-dependent small RNAs modulate the quorum-sensing response in Pseudomonas aeruginosa","volume":"188","author":"Kay","year":"2006","journal-title":"J. Bacteriol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5238","DOI":"10.1128\/AEM.00637-11","article-title":"Role of exopolysaccharides in Pseudomonas aeruginosa biofilm formation and architecture","volume":"77","author":"Ghafoor","year":"2011","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2329","DOI":"10.1128\/JB.02150-12","article-title":"PelA deacetylase activity is required for Pel polysaccharide synthesis in Pseudomonas aeruginosa","volume":"195","author":"Colvin","year":"2013","journal-title":"J. Bacteriol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"11353","DOI":"10.1073\/pnas.1503058112","article-title":"Pel is a cationic exopolysaccharide that cross-links extracellular DNA in the Pseudomonas aeruginosa biofilm matrix","volume":"112","author":"Jennings","year":"2015","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3389\/fmicb.2013.00114","article-title":"Interference of bacterial cell-to-cell communication: A new concept of antimicrobial chemotherapy breaks antibiotic resistance","volume":"4","author":"Hirakawa","year":"2013","journal-title":"Front. Microbiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"761741:1","DOI":"10.1155\/2014\/761741","article-title":"Combating pathogenic microorganisms using plant-derived antimicrobials: A minireview of the mechanistic basis","volume":"2014","author":"Upadhyay","year":"2014","journal-title":"BioMed Res. Int."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1159\/000320185","article-title":"Evaluation of anti-quorum-sensing activity of edible plants and fruits through inhibition of the N-acyl-homoserine lactone system in Chromobacterium violaceum and Pseudomonas aeruginosa","volume":"56","author":"Musthafa","year":"2010","journal-title":"Chemotherapy"},{"key":"ref_36","unstructured":"Nagy, M.M. (2010). Quorum Sensing Inhibitory Activities of Various Folk-Medicinal Plants and the Thyme-tetracycline Effect. [Ph.D. Dissertation, Georgia State University]. Available online: http:\/\/scholarworks.gsu.edu\/biology_diss\/90."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1016\/j.sajb.2011.09.001","article-title":"Activity of South African medicinal plants against Listeria monocytogenes biofilms, and isolation of active compounds from Acacia karroo","volume":"78","author":"Nyila","year":"2012","journal-title":"S. Afr. J. Bot."},{"key":"ref_38","unstructured":"Eldridge, G.R., Buckle, R.N., Ellis, M., Huang, Z., and Reilly, J.E. (2014). Novel Inhibitors of Bacterial Biofilms and Related Methods. (EP2712863A1), European Patent Application."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1080\/08927014.2012.749398","article-title":"Terpenoids of plant origin inhibit morphogenesis, adhesion, and biofilm formation by Candida albicans","volume":"29","author":"Raut","year":"2012","journal-title":"Biofouling"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.phymed.2014.10.006","article-title":"Sesqui- and triterpenoids from the liverwort Lepidozia chordulifera inhibitors of bacterial biofilm and elastase activity of human pathogenic bacteria","volume":"22","author":"Gilabert","year":"2015","journal-title":"Phytomedicine"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1173","DOI":"10.1016\/j.phymed.2012.07.003","article-title":"Inhibition of quorum sensing in Pseudomonas aeruginosa by sesquiterpene lactones","volume":"19","author":"Amaya","year":"2012","journal-title":"Phytomedicine"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.phytochem.2016.02.012","article-title":"Quorum sensing inhibitory potential and molecular docking studies of sesquiterpene lactones from Vernonia blumeoides","volume":"126","author":"Aliyu","year":"2016","journal-title":"Phytochemistry"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Ha, D.-G., and O\u2019Toole, G.A. (2015). c-di-GMP and its effects on biofilm formation and dispersion: A Pseudomonas aeruginosa review. Microbiol. Spectr., 3.","DOI":"10.1128\/microbiolspec.MB-0003-2014"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2066","DOI":"10.1128\/AAC.02499-12","article-title":"Bis-(3\u2032-5\u2032)-cyclic dimeric GMP regulates antimicrobial peptide resistance in Pseudomonas aeruginosa","volume":"57","author":"Chua","year":"2013","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"2164","DOI":"10.1128\/JB.01623-06","article-title":"Identification of genes involved in swarming motility using a Pseudomonas aeruginosa PAO1 mini-Tn5-lux mutant library","volume":"189","author":"Overhage","year":"2007","journal-title":"J. Bacteriol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"2005","DOI":"10.1099\/mic.0.26154-0","article-title":"rhlA is required for the production of a novel biosurfactant promoting swarming motility in Pseudomonas aeruginosa: 3-(3-hydoxyalkanoyloxy)alkanoic acids (HAAs), the precursors of rhamnolipids","volume":"149","author":"Deziel","year":"2003","journal-title":"Microbiology"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1099\/mic.0.030973-0","article-title":"Role of PvdQ in Pseudomonas aeruginosa virulence under iron-limiting conditions","volume":"156","author":"Jimenez","year":"2010","journal-title":"Microbiology"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1705","DOI":"10.1111\/j.1462-2920.2011.02503.x","article-title":"Distinct roles of extracellular polymeric substances in Pseudomonas aeruginosa biofilm development","volume":"13","author":"Yang","year":"2011","journal-title":"Environ. Microbiol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"8213","DOI":"10.1128\/JB.01202-06","article-title":"Analysis of Pseudomonas aeruginosa Conditional Psl Variants Reveals Roles for the Psl Polysaccharide in Adhesion and Maintaining Biofilm Structure Postattachment","volume":"188","author":"Ma","year":"2006","journal-title":"J. Bacteriol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2080","DOI":"10.1128\/JB.185.7.2080-2095.2003","article-title":"Microarray analysis of Pseudomonas aeruginosa quorum-sensing regulons: Effects of growth phase and environment","volume":"185","author":"Wagner","year":"2003","journal-title":"J. Bacteriol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1072","DOI":"10.1111\/j.1365-2958.2009.06832.x","article-title":"Global position analysis of the Pseudomonas aeruginosa quorum-sensing transcription factor LasR","volume":"73","author":"Gilbert","year":"2009","journal-title":"Mol. Microbiol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1046\/j.1365-2958.2003.03672.x","article-title":"The Pseudomonas aeruginosa quinolone signal molecule overcomes the cell density-dependency of the quorum sensing hierarchy, regulates rhl-dependent genes at the onset of stationary phase and can be produced in the absence of LasR","volume":"50","author":"Diggle","year":"2003","journal-title":"Mol. Microbiol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1254","DOI":"10.1038\/nprot.2007.158","article-title":"Biosensor-based assays for PQS, HHQ and related 2-alkyl-4-quinolone quorum sensing signal molecules","volume":"2","author":"Fletcher","year":"2007","journal-title":"Nat. Protoc."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"4022","DOI":"10.1128\/AEM.71.7.4022-4034.2005","article-title":"Differential gene expression for investigation of Escherichia coli biofilm inhibition by plant extract ursolic acid","volume":"71","author":"Ren","year":"2005","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_55","first-page":"214","article-title":"Ubiquitous ursolic acid: A potential pentacyclic triterpene natural product","volume":"2","author":"Babalola","year":"2013","journal-title":"J. Pharmacogn. Phytochem."},{"key":"ref_56","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_57","first-page":"228","article-title":"Cassipourol: A monocyclic diterpenoid with larvicidal activity from Croton funckianus","volume":"10","author":"Vegas","year":"2011","journal-title":"Boletin Latinoam. Caribe Plantas Med. Aromat."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1021\/jf1041382","article-title":"Xanthine oxidase inhibitory triterpenoid and phloroglucinol from guttiferaceous plants inhibit growth and induced apoptosis in human NTB1 cells through a ROS dependent mechanism","volume":"59","author":"Lin","year":"2011","journal-title":"J. Agric. Food Chem."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1155\/JBB.2005.242","article-title":"Genotoxic and cytotoxic studies of \u03b2-sitosterol and pteropodine in mouse","volume":"2005","author":"Gallaga","year":"2005","journal-title":"BioMed Res. Int."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"10509","DOI":"10.1093\/nar\/17.24.10509","article-title":"Transformation of Pseudomonas aeruginosa by electroporation","volume":"17","author":"Smith","year":"1989","journal-title":"Nucleic Acids Res."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1016\/j.phytochem.2008.12.005","article-title":"Bacterial resistance modifying tetrasaccharide agents from Ipomoea murucoides","volume":"70","author":"Gibbons","year":"2009","journal-title":"Phytochemistry"},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"476","DOI":"10.1016\/j.jep.2007.04.003","article-title":"Direct and indirect antimicrobial effects and antioxidant activity of Cordia gilletii De Wild (Boraginaceae)","volume":"112","author":"Okusa","year":"2007","journal-title":"J. Ethnopharmacol."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"11181","DOI":"10.1074\/jbc.270.19.11181","article-title":"Control of the Escherichia coli rrnB P1 promoter strength by ppGpp","volume":"270","author":"Zhang","year":"1995","journal-title":"J. Biol. Chem."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"178","DOI":"10.3389\/fmicb.2014.00178","article-title":"Anti-virulence activity of azithromycin in Pseudomonas aeruginosa","volume":"5","author":"Imperi","year":"2014","journal-title":"Front. Microbiol."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"3183","DOI":"10.1128\/AEM.02233-06","article-title":"Inhibition of quorum sensing Pseudomonas aeruginosa by N-acyl cyclopentylamides","volume":"73","author":"Ishida","year":"2007","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"3674","DOI":"10.1128\/AAC.00665-06","article-title":"Novel Pseudomonas aeruginosa quorum-sensing inhibitors identified in an ultra-high-throughput screen","volume":"50","author":"Schuster","year":"2006","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_67","doi-asserted-by":"crossref","unstructured":"Rasamiravaka, T., Vandeputte, O.M., and El Jaziri, M. (2016). Procedure for Rhamnolipids Quantification Using Methylene-Blue. Bio-Protocol, 6.","DOI":"10.21769\/BioProtoc.1783"},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1139\/W10-013","article-title":"Growth inhibition of adherent Pseudomonas aeruginosa by an N-butanoyl-l-homoserine lactone analog","volume":"56","author":"Khalilzadeh","year":"2010","journal-title":"Can. J. Microbiol."},{"key":"ref_69","first-page":"196","article-title":"Antibiotic synergy test: Chequerboard method on multi drug resistant Pseudomonas aeruginosa","volume":"2","author":"Jain","year":"2011","journal-title":"Int. Res. J. Pharm."},{"key":"ref_70","first-page":"1","article-title":"In vitro antibacterial and antibiotic-potentiation activities of four edible plants against multidrug-resistant Gram-negative species","volume":"13","author":"Noumedem","year":"2013","journal-title":"BMC Complement. Altern. Med."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"924","DOI":"10.1099\/mic.0.064378-0","article-title":"Endemic malagasy Dalbergia species inhibit quorum sensing in Pseudomonas aeruginosa PAO1","volume":"159","author":"Rasamiravaka","year":"2013","journal-title":"Microbiology"},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1007\/978-1-4939-0473-0_7","article-title":"Plate-based assay for swimming motility in Pseudomonas aeruginosa","volume":"1149","author":"Ha","year":"2014","journal-title":"Pseudomonas Methods Protoc."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"5934","DOI":"10.1128\/jb.175.18.5934-5944.1993","article-title":"The pilG gene product, required for Pseudomonas aeruginosa pilus production and twitching motility, is homologous to the enteric single-domain response regulator CheY","volume":"175","author":"Darzins","year":"1993","journal-title":"J. Bacteriol."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/18\/6\/1270\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:39:02Z","timestamp":1760207942000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/18\/6\/1270"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,6,14]]},"references-count":73,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2017,6]]}},"alternative-id":["ijms18061270"],"URL":"https:\/\/doi.org\/10.3390\/ijms18061270","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,6,14]]}}}