#PAGE_PARAMS# #ADS_HEAD_SCRIPTS# #MICRODATA#

Necrotrophism Is a Quorum-Sensing-Regulated Lifestyle in


How pathogenic bacteria infect and kill their host is currently widely investigated. In comparison, the fate of pathogens after the death of their host receives less attention. We studied Bacillus thuringiensis (Bt) infection of an insect host, and show that NprR, a quorum sensor, is active after death of the insect and allows Bt to survive in the cadavers as vegetative cells. Transcriptomic analysis revealed that NprR regulates at least 41 genes, including many encoding degradative enzymes or proteins involved in the synthesis of a nonribosomal peptide named kurstakin. These degradative enzymes are essential in vitro to degrade several substrates and are specifically expressed after host death suggesting that Bt has an active necrotrophic lifestyle in the cadaver. We show that kurstakin is essential for Bt survival during necrotrophic development. It is required for swarming mobility and biofilm formation, presumably through a pore forming activity. A nprR deficient mutant does not develop necrotrophically and does not sporulate efficiently in the cadaver. We report that necrotrophism is a highly regulated mechanism essential for the Bt infectious cycle, contributing to spore spreading.


Vyšlo v časopise: Necrotrophism Is a Quorum-Sensing-Regulated Lifestyle in. PLoS Pathog 8(4): e32767. doi:10.1371/journal.ppat.1002629
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.ppat.1002629

Souhrn

How pathogenic bacteria infect and kill their host is currently widely investigated. In comparison, the fate of pathogens after the death of their host receives less attention. We studied Bacillus thuringiensis (Bt) infection of an insect host, and show that NprR, a quorum sensor, is active after death of the insect and allows Bt to survive in the cadavers as vegetative cells. Transcriptomic analysis revealed that NprR regulates at least 41 genes, including many encoding degradative enzymes or proteins involved in the synthesis of a nonribosomal peptide named kurstakin. These degradative enzymes are essential in vitro to degrade several substrates and are specifically expressed after host death suggesting that Bt has an active necrotrophic lifestyle in the cadaver. We show that kurstakin is essential for Bt survival during necrotrophic development. It is required for swarming mobility and biofilm formation, presumably through a pore forming activity. A nprR deficient mutant does not develop necrotrophically and does not sporulate efficiently in the cadaver. We report that necrotrophism is a highly regulated mechanism essential for the Bt infectious cycle, contributing to spore spreading.


Zdroje

1. RaymondBJohnstonPRNielsen-LeRouxCLereclusDCrickmoreN 2010 Bacillus thuringiensis: an impotent pathogen? Trends Microbiol 18 189 194

2. Toledo-AranaADussurgetONikitasGSestoNGuet-RevilletH 2009 The Listeria transcriptional landscape from saprophytism to virulence. Nature 459 950 956

3. IvanovaNSorokinAAndersonIGalleronNCandelonB 2003 Genome sequence of Bacillus cereus and comparative analysis with Bacillus anthracis. Nature 423 87 91

4. MartinPAWTraversRS 1989 Worldwide abundance and distribution of Bacillus thuringiensis isolates. Appl Environ Microbiol 55 2437 2442

5. Vilas-BoasLAVilas-BoasGFSaridakisHOLemosMVLereclusD 2000 Survival and conjugation of Bacillus thuringiensis in a soil microcosm. FEMS Microbiol Ecol 31 255 259

6. JensenGBHansenBMEilenbergJMahillonJ 2003 The hidden lifestyles of Bacillus cereus and relatives. Environ Microbiol 5 631 640

7. SchnepfECrickmoreNVan RieJLereclusDBaumJ 1998 Bacillus thuringiensis and its pesticidal crystal proteins. Microbiol Mol Biol Rev 62 775 806

8. DuCNickersonKW 1996 Bacillus thuringiensis HD-73 Spores Have Surface-Localized Cry1Ac Toxin: Physiological and Pathogenic Consequences. Appl Environ Microbiol 62 3722 3726

9. SalamitouSRamisseFBrehélinMBourguetDGiloisN 2000 The plcR regulon is involved in the opportunistic properties of Bacillus thuringiensis and Bacillus cereus in mice and insects. Microbiology 146 2825 2832

10. AgaisseHGominetMØkstadOAKolstøABLereclusD 1999 PlcR is a pleiotropic regulator of extracellular virulence factor gene expression in Bacillus thuringiensis. Mol Microbiol 32 1043 1053

11. SlamtiLLereclusD 2002 A cell-cell signaling peptide activates the PlcR virulence regulon in bacteria of the Bacillus cereus group. EMBO J 21 4550 4559

12. GoharMFaegriKPerchatSRavnumSØkstadOA 2008 The PlcR virulence regulon of Bacillus cereus. PLoS ONE 3 e2793

13. GoharMØkstadOAGiloisNSanchisVKolstøA-B 2002 Two-dimensional electrophoresis analysis of the extracellular proteome of Bacillus cereus reveals the importance of the PlcR regulon. Proteomics 2 784 791

14. LereclusDAgaisseHGrandvaletCSalamitouSGominetM 2000 Regulation of toxin and virulence gene transcription in Bacillus thuringiensis. Int J Med Microbiol 290 295 299

15. ChitlaruTGatOGozlanYArielNShaffermanA 2006 Differential proteomic analysis of the Bacillus anthracis secretome: distinct plasmid and chromosome CO2-dependent cross talk mechanisms modulate extracellular proteolytic activities. J Bacteriol 188 3551 3571

16. PerchatSDuboisTZouhirSGominetMPoncetS 2011 A cell-cell communication system regulates protease production during sporulation in bacteria of the Bacillus cereus group. Mol Microbiol 82 619 633

17. ChungMCPopovaTGMillisBAMukherjeeDVZhouW 2006 Secreted neutral metalloproteases of Bacillus anthracis as candidate pathogenic factors. J Biol Chem 281 31408 31418

18. Hajaij-EllouzeMFedhilaSLereclusDNielsen-LeRouxC 2006 The enhancin-like metalloprotease from the Bacillus cereus group is regulated by the pleiotropic transcriptional activator PlcR but is not essential for larvicidal activity. FEMS Microbiol Lett 260 9 16

19. HilbertDWPiggotPJ 2004 Compartmentalization of gene expression during Bacillus subtilis spore formation. Microbiol Mol Biol Rev 68 234 262

20. BravoAAgaisseHSalamitouSLereclusD 1996 Analysis of cryIAa expression in sigE and sigK mutants of Bacillus thuringiensis. Mol Gen Genet 250 734 741

21. HathoutYHoYPRyzhovVDemirevPFenselauC 2000 Kurstakins: a new class of lipopeptides isolated from Bacillus thuringiensis. J Nat Prod 63 1492 1496

22. BumpusSBEvansBSThomasPMNtaiIKelleherNL 2009 A proteomics approach to discovering natural products and their biosynthetic pathways. Nat Biotechnol 27 951 956

23. AbderrahmaniATapiANatecheFCholletMLeclereV 2011 Bioinformatics and molecular approaches to detect NRPS genes involved in the biosynthesis of kurstakin from Bacillus thuringiensis. Appl Microbiol Biotechnol 92 571 81

24. KinsingerRFShirkMCFallR 2003 Rapid surface motility in Bacillus subtilis is dependent on extracellular surfactin and potassium ion. J Bacteriol 185 5627 5631

25. JulkowskaDObuchowskiMHollandIBSerorSJ 2004 Branched swarming patterns on a synthetic medium formed by wild-type Bacillus subtilis strain 3610: detection of different cellular morphologies and constellations of cells as the complex architecture develops. Microbiology 150 1839 1849

26. LopezDFischbachMAChuFLosickRKolterR 2009 Structurally diverse natural products that cause potassium leakage trigger multicellularity in Bacillus subtilis. Proc Natl Acad Sci U S A 106 280 285

27. HouryABriandetRAymerichSGoharM 2010 Involvement of motility and flagella in Bacillus cereus biofilm formation. Microbiology 156 1009 1018

28. FedhilaSGoharMSlamtiLNelPLereclusD 2003 The Bacillus thuringiensis PlcR-regulated gene inhA2 is necessary, but not sufficient, for virulence. J Bacteriol 185 2820 2825

29. HuangCJWangTKChungSCChenCY 2005 Identification of an antifungal chitinase from a potential biocontrol agent, Bacillus cereus 28-9. J Biochem Mol Biol 38 82 88

30. DalhammarGSteinerH 1984 Characterization of inhibitor A, a protease from Bacillus thuringiensis which degrades attacins and cecropins, two classes of antibacterial proteins in insects. Eur J Biochem 139 247 252

31. RamaraoNLereclusD 2005 The InhA1 metalloprotease allows spores of the B. cereus group to escape macrophages. Cell Microbiol 7 1357 1364

32. GuillemetECadotCTranSLGuinebretiereMHLereclusD 2010 The InhA metalloproteases of Bacillus cereus contribute concomitantly to virulence. J Bacteriol 192 286 294

33. CarrilloCTeruelJAArandaFJOrtizA 2003 Molecular mechanism of membrane permeabilization by the peptide antibiotic surfactin. Biochim Biophys Acta 1611 91 97

34. SteinT 2005 Bacillus subtilis antibiotics: structures, syntheses and specific functions. Mol Microbiol 56 845 857

35. LopezDVlamakisHLosickRKolterR 2009 Paracrine signaling in a bacterium. Genes Dev 23 1631 1638

36. GominetMSlamtiLGiloisNRoseMLereclusD 2001 Oligopeptide permease is required for expression of the Bacillus thuringiensis PlcR regulon and for virulence. Mol Microbiol 40 963 975

37. PeregoMHochJA 1996 Protein aspartate phosphatases control the output of two-component signal transduction systems. Trends Genet 12 97 101

38. LazazzeraBAGrossmanAD 1998 The ins and outs of peptide signaling. Trends Microbiol 6 288 294

39. BongiorniCStoesselRShoemakerDPeregoM 2006 Rap phosphatase of virulence plasmid pXO1 inhibits Bacillus anthracis sporulation. J Bacteriol 188 487 498

40. MargulisLJorgensenJZDolanSKolchinskyRRaineyFA 1998 The Arthromitus stage of Bacillus cereus: intestinal symbionts of animals. Proc Natl Acad Sci U S A 95 1236 1241

41. SaileEKoehlerTM 2006 Bacillus anthracis multiplication, persistence, and genetic exchange in the rhizosphere of grass plants. Appl Environ Microbiol 72 3168 3174

42. LereclusDArantesOChaufauxJLecadetM-M 1989 Transformation and expression of a cloned ∂-endotoxin gene in Bacillus thuringiensis. FEMS Microbiol Lett 60 211 218

43. KolstøABTourasseNJØkstadOA 2009 What sets Bacillus anthracis apart from other Bacillus species? Annu Rev Microbiol 63 451 476

44. DowerWJMillerJFRagsdaleCW 1988 High efficiency transformation of E. coli by high voltage electroporation. Nucleic Acids Res 16 6127 6145

45. LecadetMMBlondelMORibierJ 1980 Generalized transduction in Bacillus thuringiensis var. berliner 1715, using bacteriophage CP54 Ber. J Gen Microbiol 121 203 212

46. LereclusDValladeMChaufauxJArantesORambaudS 1992 Expansion of insecticidal host range of Bacillus thuringiensis by in vivo genetic recombination. Bio/Technology 10 418 421

47. AgaisseHLereclusD 1994 Structural and functional analysis of the promoter region involved in full expression of the cryIIIA toxin gene of Bacillus thuringiensis. Mol Microbiol 13 97 107

48. de BarjacHCosmao-DumanoirV 1975 Interest of some additional biochemical tests for the classification of “Bacillus” (author's transl). Ann Microbiol (Paris) 126 83 95

49. BouillautLRamaraoNBuissonCGiloisNGoharM 2005 FlhA influences Bacillus thuringiensis PlcR-regulated gene transcription, protein production, and virulence. Appl Environ Microbiol 71 8903 8910

50. SmythGK 2004 Linear models and empirical bayes methods for assessing differential expression in microarray experiments. Stat Appl Genet Mol Biol 3 Article3

51. SmythGKSpeedT 2003 Normalization of cDNA microarray data. Methods 31 265 273

52. SmythGK 2005 Limma: Linear models for microarray data. GentlemanVCRDudoitSIrizarryRHuberW Bioinformatics and Computational Biology Solutions using R and Bioconductor New York Springer 397 420

53. R-Development-Core-Team 2005 R: A language and environment for statistical computing Vienna (Austria) R Foundation for Statistical Computing Available: http://www.R-project.org

54. BrulandTAnderssenEDosethBBergumHBeisvagV 2007 Optimization of cDNA microarrays procedures using criteria that do not rely on external standards. BMC Genomics 8 377

Štítky
Hygiena a epidemiológia Infekčné lekárstvo Laboratórium

Článok vyšiel v časopise

PLOS Pathogens


2012 Číslo 4
Najčítanejšie tento týždeň
Najčítanejšie v tomto čísle
Kurzy

Zvýšte si kvalifikáciu online z pohodlia domova

Získaná hemofilie - Povědomí o nemoci a její diagnostika
nový kurz

Eozinofilní granulomatóza s polyangiitidou
Autori: doc. MUDr. Martina Doubková, Ph.D.

Všetky kurzy
Prihlásenie
Zabudnuté heslo

Zadajte e-mailovú adresu, s ktorou ste vytvárali účet. Budú Vám na ňu zasielané informácie k nastaveniu nového hesla.

Prihlásenie

Nemáte účet?  Registrujte sa

#ADS_BOTTOM_SCRIPTS#