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The Anti-Sigma Factor TcdC Modulates Hypervirulence in an Epidemic BI/NAP1/027 Clinical Isolate of


Nosocomial infections are increasingly being recognised as a major patient safety issue. The modern hospital environment and associated health care practices have provided a niche for the rapid evolution of microbial pathogens that are well adapted to surviving and proliferating in this setting, after which they can infect susceptible patients. This is clearly the case for bacterial pathogens such as Methicillin Resistant Staphylococcus aureus (MRSA) and Vancomycin Resistant Enterococcus (VRE) species, both of which have acquired resistance to antimicrobial agents as well as enhanced survival and virulence properties that present serious therapeutic dilemmas for treating physicians. It has recently become apparent that the spore-forming bacterium Clostridium difficile also falls within this category. Since 2000, there has been a striking increase in C. difficile nosocomial infections worldwide, predominantly due to the emergence of epidemic or hypervirulent isolates that appear to possess extended antibiotic resistance and virulence properties. Various hypotheses have been proposed for the emergence of these strains, and for their persistence and increased virulence, but supportive experimental data are lacking. Here we describe a genetic approach using isogenic strains to identify a factor linked to the development of hypervirulence in C. difficile. This study provides evidence that a naturally occurring mutation in a negative regulator of toxin production, the anti-sigma factor TcdC, is an important factor in the development of hypervirulence in epidemic C. difficile isolates, presumably because the mutation leads to significantly increased toxin production, a contentious hypothesis until now. These results have important implications for C. difficile pathogenesis and virulence since they suggest that strains carrying a similar mutation have the inherent potential to develop a hypervirulent phenotype.


Vyšlo v časopise: The Anti-Sigma Factor TcdC Modulates Hypervirulence in an Epidemic BI/NAP1/027 Clinical Isolate of. PLoS Pathog 7(10): e32767. doi:10.1371/journal.ppat.1002317
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.ppat.1002317

Souhrn

Nosocomial infections are increasingly being recognised as a major patient safety issue. The modern hospital environment and associated health care practices have provided a niche for the rapid evolution of microbial pathogens that are well adapted to surviving and proliferating in this setting, after which they can infect susceptible patients. This is clearly the case for bacterial pathogens such as Methicillin Resistant Staphylococcus aureus (MRSA) and Vancomycin Resistant Enterococcus (VRE) species, both of which have acquired resistance to antimicrobial agents as well as enhanced survival and virulence properties that present serious therapeutic dilemmas for treating physicians. It has recently become apparent that the spore-forming bacterium Clostridium difficile also falls within this category. Since 2000, there has been a striking increase in C. difficile nosocomial infections worldwide, predominantly due to the emergence of epidemic or hypervirulent isolates that appear to possess extended antibiotic resistance and virulence properties. Various hypotheses have been proposed for the emergence of these strains, and for their persistence and increased virulence, but supportive experimental data are lacking. Here we describe a genetic approach using isogenic strains to identify a factor linked to the development of hypervirulence in C. difficile. This study provides evidence that a naturally occurring mutation in a negative regulator of toxin production, the anti-sigma factor TcdC, is an important factor in the development of hypervirulence in epidemic C. difficile isolates, presumably because the mutation leads to significantly increased toxin production, a contentious hypothesis until now. These results have important implications for C. difficile pathogenesis and virulence since they suggest that strains carrying a similar mutation have the inherent potential to develop a hypervirulent phenotype.


Zdroje

1. BorrielloSP 1998 Pathogenesis of Clostridium difficile infection. J Antimicrob Chemother 41 13 19

2. WarnyMPepinJFangAKillgoreGThompsonA 2005 Toxin production by an emerging strain of Clostridium difficile associated with outbreaks of severe disease in North America and Europe. Lancet 366 1079 1084

3. McDonaldLCKillgoreGEThompsonAOwensRCKazakovaSV 2005 An epidemic, toxin gene–variant strain of Clostridium difficile. N Engl J Med 353 2433 2441

4. StablerRAHeMDawsonLMartinMValienteE 2009 Comparative genome and phenotypic analysis of Clostridium difficile 027 strains provides insight into the evolution of a hypervirulent bacterium. Genome Biol 10 R102

5. LooVGPoirierLMillerMAOughtonMLibmanMD 2005 A predominantly clonal multi-institutional outbreak of Clostridium difficile-associated diarrhea with high morbidity and mortality. N Engl J Med 353 2442 2449

6. MutoCAPokrywkaMShuttKMendelsohnABNouriK 2005 A large outbreak of Clostridium difficile-associated disease with an unexpected proportion of deaths and colectomies at a teaching hospital following increased fluoroquinolone use. Infect Control Hosp Epidemiol 26 273 280

7. KuijperEJCoignardBTullP 2006 Emergence of Clostridium difficile-associated disease in North America and Europe. Clin Microbiol Infect 12 Suppl 6 2 18

8. RouphaelNGO'DonnellJABhatnagarJLewisFPolgreenPM 2008 Clostridium difficile-associated diarrhea: an emerging threat to pregnant women. Am J Obstet Gynecol 198 635 e631 636

9. ZilberbergMDTillotsonGSMcDonaldC 2010 Clostridium difficile infections among hospitalized children, United States, 1997–2006. Emerg Infect Dis 16 604 609

10. BakerSSFadenHSayejWPatelRBakerRD 2010 Increasing Incidence of Community-Associated Atypical Clostridium difficile Disease in Children. Clin Pediatr (Phila) 49 644 647

11. RileyTV 2009 Is Clostridium difficile a threat to Australia's biosecurity? Med J Aust 190 661 662

12. MerriganMVenugopalAMallozziMRoxasBViswanathanVK 2010 Human Hypervirulent Clostridium difficile Strains Exhibit Increased Sporulation as Well as Robust Toxin Production. J Bacteriol 192 4904 4911

13. SebaihiaMWrenBWMullanyPFairweatherNFMintonN 2006 The multidrug-resistant human pathogen Clostridium difficile has a highly mobile, mosaic genome. Nat Genet 38 779 786

14. JustISelzerJWilmMvon Eichel-StreiberCMannM 1995 Glucosylation of Rho proteins by Clostridium difficile toxin B. Nature 375 500 503

15. LyrasDO'ConnorJRHowarthPKSambolSPCarterGP 2009 Toxin B is essential for virulence of Clostridium difficile. Nature 458 1176 1179

16. KuehneSACartmanSTHeapJTKellyMLCockayneA 2010 The role of toxin A and toxin B in Clostridium difficile infection. Nature 467 711 713

17. BraunVHundsbergerTLeukelPSauerbornMEichel-StreiberCv 1996 Definition of the single integration site of the pathogenicity locus in Clostridium difficile. Gene 181 29 38

18. ManiNDupuyB 2001 Regulation of toxin synthesis in Clostridium difficile by an alternative RNA polymerase sigma factor. Proc Natl Acad Sci U S A 98 5844 5849

19. TanKSWeeBYSongKP 2001 Evidence for holin function of tcdE gene in the pathogenicity of Clostridium difficile. J Med Microbiol 50 613 619

20. MatamourosSEnglandPDupuyB 2007 Clostridium difficile toxin expression is inhibited by the novel regulator TcdC. Mol Microbiol 64 1274 1288

21. DupuyBGovindRAntunesAMatamourosS 2008 Clostridium difficile toxin synthesis is negatively regulated by TcdC. J Med Microbiol 57 685 689

22. MurrayRBoydDLevettPNMulveyMRAlfaMJ 2009 Truncation in the tcdC region of the Clostridium difficile PathLoc of clinical isolates does not predict increased biological activity of Toxin B or Toxin A. BMC Infect Dis 9 103

23. ManiNLyrasDBarrosoLHowarthPWilkinsT 2002 Environmental response and autoregulation of Clostridium difficile TxeR, a sigma factor for toxin gene expression. J Bacteriol 184 5971 5978

24. O'ConnorJRLyrasDFarrowKAAdamsVPowellDR 2006 Construction and analysis of chromosomal Clostridium difficile mutants. Mol Microbiol 61 1335 1351

25. BurnsDAHeapJTMintonNP 2010 SleC is essential for germination of Clostridium difficile spores in nutrient-rich medium supplemented with the bile salt taurocholate. J Bacteriol 192 657 664

26. CartmanSTMintonNP 2010 A mariner-based transposon system for in vivo random mutagenesis of Clostridium difficile. Appl Environ Microbiol 76 1103 1109

27. HeapJTKuehneSAEhsaanMCartmanSTCooksleyCM 2010 The ClosTron: Mutagenesis in Clostridium refined and streamlined. J Microbiol Methods 80 49 55

28. NallapareddySRSinghKVMurrayBE 2006 Construction of improved temperature-sensitive and mobilizable vectors and their use for constructing mutations in the adhesin-encoding acm gene of poorly transformable clinical Enterococcus faecium strains. Appl Environ Microbiol 72 334 345

29. CarterGPLyrasDAllenDLMackinKEHowarthPM 2007 Binary toxin production in Clostridium difficile is regulated by CdtR, a LytTR family response regulator. J Bacteriol 189 7290 7301

30. AwadMMRoodJI 1997 Isolation of a-toxin, q-toxin and k-toxin mutants of Clostridium perfringens by Tn916 mutagenesis. Microb Pathogen 22 275 284

31. HundsbergerTBraunVWeidmannMLeukelPSauerbornM 1997 Transcription analysis of the genes tcdA-E of the pathogenicity locus of Clostridium difficile. European J Bioch 244 735 742

32. RazaqNSambolSNagaroKZukowskiWCheknisA 2007 Infection of hamsters with historical and epidemic BI types of Clostridium difficile. J Infect Dis 196 1813 1819

33. GouldingDThompsonHEmersonJFairweatherNFDouganG 2009 Distinctive profiles of infection and pathology in hamsters infected with Clostridium difficile strains 630 and B1. Infect Immun 77 5478 5485

34. HeMSebaihiaMLawleyTDStablerRADawsonLF 2010 Evolutionary dynamics of Clostridium difficile over short and long time scales. Proc Natl Acad Sci U S A 107 7527 7532

35. RupnikMAvesaniVJancMvon Eichel-StreiberCDelmeeM 1998 A novel toxinotyping scheme and correlation of toxinotypes with serogroups of Clostridium difficile isolates. J Clin Microbiol 36 2240 2247

36. RichardsMKnoxJElliottBMackinKLyrasD 2011 Severe infection with Clostridium difficile PCR ribotype 027 acquired in Melbourne, Australia. Med J Australia 194 369 371

37. CurrySRMarshJWMutoCAO'LearyMMPasculleAW 2007 tcdC genotypes associated with severe TcdC truncation in an epidemic clone and other strains of Clostridium difficile. J Clin Microbiol 45 215 221

38. LyerlyDMBarrosoLAWilkinsTDDepitreCCorthierG 1992 Characterization of a toxin A-negative, toxin B-positive strain of Clostridium difficile. Infect Immun 60 4633 4639

39. CarterGPRoodJILyrasD 2010 The role of toxin A and toxin B in Clostridium difficile-associated disease: Past and present perspectives. Gut Microbes 1 58 64

40. O'ConnorJRJohnsonSGerdingDN 2009 Clostridium difficile infection caused by the epidemic BI/NAP1/027 strain. Gastroenterology 136 1913 1924

41. HeapJTPenningtonOJCartmanSTCarterGPNP.M 2007 The ClosTron: a universal gene knock-out system for the genus Clostridium. J Microbiol Meth 70 452 464

42. MullanyPWilksMTabaqchaliS 1991 Transfer of Tn916 and Tn916DE into Clostridium difficile: demonstration of a hot-spot for these elemnets in the C. difficile genome. FEMS Microbiol Lett 79 191 194

43. MintonNCarterGHerbertMO'KeeffeTPurdyD 2004 The development of Clostridium difficile genetic systems. Anaerobe 10 75 84

44. GoorhuisADebastSBvan LeengoedLAHarmanusCNotermansDW 2008 Clostridium difficile PCR ribotype 078: an emerging strain in humans and in pigs? J Clin Microbiol 46 1157; author reply 1158

45. DawsonLFValienteEWrenBW 2009 Clostridium difficile–a continually evolving and problematic pathogen. Infect Genet Evol 9 1410 1417

46. StablerRADawsonLFPhuaLTWrenBW 2008 Comparative analysis of BI/NAP1/027 hypervirulent strains reveals novel toxin B-encoding gene (tcdB) sequences. J Med Microbiol 57 771 775

47. LanisJMBaruaSBallardJD 2010 Variations in TcdB activity and the hypervirulence of emerging strains of Clostridium difficile. PLoS Pathog 6 e1001061

48. SchwanCStecherBTzivelekidisTvan HamMRohdeM 2009 Clostridium difficile toxin CDT induces formation of microtubule-based protrusions and increases adherence of bacteria. PLoS Pathog 5 e1000626

49. AkerlundTPerssonIUnemoMNorenTSvenungssonB 2008 Increased sporulation rate of epidemic Clostridium difficile Type 027/NAP1. J Clin Microbiol 46 1530 1533

50. LawleyTDClareSWalkerAWGouldingDStablerRA 2009 Antibiotic treatment of Clostridium difficile carrier mice triggers a supershedder state, spore-mediated transmission, and severe disease in immunocompromised hosts. Infect Immun 77 3661 3669

51. JohnsonS 2009 Recurrent Clostridium difficile infection: a review of risk factors, treatments, and outcomes. J Infect 58 403 410

52. LindsayJA 2010 Genomic variation and evolution of Staphylococcus aureus. Int J Med Microbiol 300 98 103

53. BontenMJWillemsRWeinsteinRA 2001 Vancomycin-resistant enterococci: why are they here, and where do they come from? Lancet Infect Dis 1 314 325

54. SmithCJMarkowitzSMMacrinaFL 1981 Transferable tetracycline resistance in Clostridium difficile. Antimicrob Agents and Chemother 19 997 1003

55. SambrookJRussellDW 2001 Molecular Cloning: A Laboratory Manual Cold Spring Harbor, NY Cold Spring Harbor Laboratory Press

56. AwadMMBryantAEStevensDLRoodJI 1995 Virulence studies on chromosomal a-toxin and q-toxin mutants constructed by allelic exchange provide genetic evidence for the essential role of a-toxin in Clostridium perfringens-mediated gas gangrene. Mol Microbiol 15 191 202

57. GovindRVediyappanGRolfeRDFralickJA 2006 Evidence that Clostridium difficile TcdC is a membrane-associated protein. J Bacteriol 188 3716 3720

58. AbramoffMDMagelhaesPJRamSJ 2004 Image Processing with ImageJ. Biophotonics Internatl 11 36 42

59. MarshJWO'LearyMMShuttKAPasculleAWJohnsonS 2006 Multilocus variable-number tandem-repeat analysis for investigation of Clostridium difficile transmission in Hospitals. J Clin Microbiol 44 2558 2566

60. BoyerHWRoulland-DussoixD 1969 A complementation analysis of the restriction and modification of DNA in Escherichia coli. J Mol Biol 41 459 472

61. WustJSullivanNMHardeggerUWilkinsTD 1982 Investigation of an outbreak of antibiotic-associated colitis by various typing methods. J Clin Microbiol 16 1096 1101

62. MullanyPWilksMLambIClaytonCWrenB 1990 Genetic analysis of a tetracycline resistance element from Clostridium difficile and its conjugal transfer to and from Bacillus subtilis. J Gen Microbiol 136 1343 1349

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Hygiena a epidemiológia Infekčné lekárstvo Laboratórium

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PLOS Pathogens


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