title: Isolation of the autoinducer-quenching strain that inhibits LasR in Pseudomonas aeruginosa.
abstract: Quorum sensing (QS) has been recognized as a general phenomenon in microorganisms and plays an important role in many pathogenic bacteria. In this report, we used the Agrobacterium tumefaciens biosensor strain NT1 to rapidly screen for autoinducer-quenching inhibitors from bacteria. After initial screening 5389 isolates obtained from land and beach soil, 53 putative positive strains were identified. A confirmatory bioassay was carried out after concentrating the putative positive culture supernatant, and 22 strains were confirmed to have anti-LasR activity. Finally, we determined the strain JM2, which could completely inhibit biofilm formation of Pseudomonas aeruginosa PAO1, belonged to the genus Pseudomonas by analysis of 16S rDNA. Partially purified inhibitor factor(s) F5 derived from culture supernatants specifically inhibited LasR-controlled elastase and protease in wild type P. aeruginosa PAO1 by 68% and 73%, respectively, without significantly affecting growth; the rhl-controlled pyocyanin and rhamnolipids were inhibited by 54% and 52% in the presence of 100 µg/mL of F5. The swarming motility and biofilm of PAO1 were also inhibited by F5. Real time RT-PCR on samples from 100 µg/mL F5-treated P. aeruginosa showed downregulation of autoinducer synthase (LasRI and rhlI) and cognate receptor (lasR and rhlR) genes by 50%, 28%, 48%, and 29%, respectively. These results provide compelling evidence that the F5 inhibitor(s) interferes with the las system and significantly inhibits biofilm formation.
authors.affiliation: School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210046, Jiangsu, China. iamlhwang@njupt.edu.cn.
authors.forename: Lixing
authors.initials: L
authors.lastname: Weng
authors.affiliation: Jiangsu Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, Jiangsu, China. 082023005@fudan.edu.cn.
authors.forename: Yuqian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China. 09210700014@fudan.edu.cn.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, Jiangsu, China. iamlhwang@njupt.edu.cn.
authors.forename: Lianhui
authors.initials: L
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D018441:Biofilms / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D015536:Down-Regulation; D008025:Ligases / Q000037:antagonists & inhibitors / Q000378:metabolism; D010802:Phylogeny; D011549:Pseudomonas / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification* / Q000378:metabolism*; D053038:Quorum Sensing / Q000187:drug effects; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D012988:Soil Microbiology; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; C080365:LasR protein, Pseudomonas aeruginosa; D012336:RNA, Ribosomal, 16S; D015534:Trans-Activators; D014157:Transcription Factors; D037521:Virulence Factors; D008025:Ligases; C096955:RHLI protein, Pseudomonas aeruginosa
references.citation: Microbiology (Reading). 2012 Aug;158(Pt 8):2089-2098
references.pmid: 22556359
references.citation: Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4638-43
references.pmid: 11930013
references.citation: J Microbiol. 2012 Dec;50(6):987-93
references.pmid: 23274985
references.citation: PLoS One. 2012;7(11):e50368
references.pmid: 23226268
references.citation: Mol Microbiol. 1996 Sep;21(6):1137-46
references.pmid: 8898383
references.citation: J Med Microbiol. 2011 Mar;60(Pt 3):300-306
references.pmid: 21127154
references.citation: Science. 1998 Apr 10;280(5361):295-8
references.pmid: 9535661
references.citation: Proc Natl Acad Sci U S A. 1999 Sep 28;96(20):11229-34
references.pmid: 10500159
references.citation: Arch Microbiol. 2012 Jun;194(6):391-403
references.pmid: 22105093
references.citation: Methods Enzymol. 2002;358:452-84
references.pmid: 12474406
references.citation: Nature. 1993 Apr 1;362(6419):446-8
references.pmid: 8464475
references.citation: Arch Intern Med. 1999 May 24;159(10):1127-32
references.pmid: 10335691
references.citation: J Antimicrob Chemother. 2010 Jan;65(1):72-8
references.pmid: 19889790
references.citation: Antimicrob Agents Chemother. 2008 Jan;52(1):198-203
references.pmid: 17938186
references.citation: Microbiology (Reading). 2009 Mar;155(Pt 3):712-723
references.pmid: 19246742
references.citation: Res Microbiol. 2010 May;161(4):293-304
references.pmid: 20381609
references.citation: Indian J Microbiol. 2013 Mar;53(1):28-35
references.pmid: 24426075
references.citation: ACS Chem Biol. 2012 Oct 19;7(10):1719-28
references.pmid: 22853441
references.citation: EMBO J. 2003 Aug 1;22(15):3803-15
references.pmid: 12881415
references.citation: J Microbiol Methods. 2004 Sep;58(3):351-60
references.pmid: 15279939
references.citation: Mar Biotechnol (NY). 2008 Jan-Feb;10(1):56-63
references.pmid: 17952508
references.citation: J Bacteriol. 2003 Apr;185(7):2080-95
references.pmid: 12644477
references.citation: Mol Microbiol. 1995 Jul;17(2):333-43
references.pmid: 7494482
references.citation: Microbiology (Reading). 2005 Dec;151(Pt 12):3873-3880
references.pmid: 16339933
references.citation: Pediatr Pulmonol. 2010 Apr;45(4):356-62
references.pmid: 20306535
references.citation: Microbiology (Reading). 2005 May;151(Pt 5):1325-1340
references.pmid: 15870443