1887

Abstract

The Gram-positive bacterium Streptococcus equi subspecies equi (S. equi) is the causative agent of strangles, among the most frequently diagnosed infectious diseases of horses worldwide. Genome analysis of S. equi strain 4047 (Se4047) identified a putative operon, Fim1, with similarity to the pilus loci of other Gram-positive bacteria. The Fim1 locus was present in all strains of S. equi and its close relative S. equi subspecies zooepidemicus (S. zooepidemicus) that have been studied to date. In this study we provide evidence that the putative structural pilus proteins, SEQ_0936 and CNE, are produced on the cell surface during in vitro growth and in vivo infection. Although the proteins encoded within the Fim1 locus are not essential for attachment or biofilm formation, over-transcription of SEQ_0936 and CNE enhanced attachment to equine tissue in vitro. Our data suggest that whilst the Fim1 locus does not produce a polymerized pilus structure, the products of the Fim1 locus may fulfil an adhesive function. The putative pilus-associated regulator, tetR, which contains a nonsense mutation in S. equi, was able to regulate transcription of the Fim1 locus following repair and over-transcription, confirming its predicted role in the operon.

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2017-07-28
2019-10-14
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References

  1. Montealegre MC, Singh KV, Somarajan SR, Yadav P, Chang C et al. Role of the Emp pilus subunits of Enterococcus faecium in biofilm formation, adherence to host extracellular matrix components, and experimental infection. Infect Immun 2016;84:1491–1500 [CrossRef][PubMed]
    [Google Scholar]
  2. Echelman DJ, Alegre-Cebollada J, Badilla CL, Chang C, Ton-That H et al. CnaA domains in bacterial pili are efficient dissipaters of large mechanical shocks. Proc Natl Acad Sci USA 2016;113:2490–2495 [CrossRef][PubMed]
    [Google Scholar]
  3. Persat A, Nadell CD, Kim MK, Ingremeau F, Siryaporn A et al. The mechanical world of bacteria. Cell 2015;161:988–997 [CrossRef][PubMed]
    [Google Scholar]
  4. Khare B, Narayana SVL. Pilus biogenesis of Gram-positive bacteria: roles of sortases and implications for assembly. Protein Sci 2017;26:1458–1473 [CrossRef][PubMed]
    [Google Scholar]
  5. Ton-That H, Marraffini LA, Schneewind O. Sortases and pilin elements involved in pilus assembly of Corynebacterium diphtheriae. Mol Microbiol 2004;53:251–261 [CrossRef][PubMed]
    [Google Scholar]
  6. Ton-That H, Schneewind O. Assembly of pili on the surface of Corynebacterium diphtheriae. Mol Microbiol 2003;50:1429–1438 [CrossRef][PubMed]
    [Google Scholar]
  7. Dramsi S, Caliot E, Bonne I, Guadagnini S, Prévost MC et al. Assembly and role of pili in group B streptococci. Mol Microbiol 2006;60:1401–1413 [CrossRef][PubMed]
    [Google Scholar]
  8. Manetti AG, Zingaretti C, Falugi F, Capo S, Bombaci M et al. Streptococcus pyogenes pili promote pharyngeal cell adhesion and biofilm formation. Mol Microbiol 2007;64:968–983 [CrossRef][PubMed]
    [Google Scholar]
  9. Hendrickx AP, Budzik JM, Oh SY, Schneewind O. Architects at the bacterial surface - sortases and the assembly of pili with isopeptide bonds. Nat Rev Microbiol 2011;9:166–176 [CrossRef][PubMed]
    [Google Scholar]
  10. Kelly C, Bugg M, Robinson C, Mitchell Z, Davis-Poynter N et al. Sequence variation of the SeM gene of Streptococcus equi allows discrimination of the source of strangles outbreaks. J Clin Microbiol 2006;44:480–486 [CrossRef][PubMed]
    [Google Scholar]
  11. Todd AG. Strangles. J Comp Pathol Ther 1910;23:212–229 [CrossRef]
    [Google Scholar]
  12. Newton JR, Wood JL, Dunn KA, Debrauwere MN, Chanter N. Naturally occurring persistent and asymptomatic infection of the guttural pouches of horses with Streptococcus equi. Vet Rec 1997;140:84–90 [CrossRef][PubMed]
    [Google Scholar]
  13. Holden MT, Heather Z, Paillot R, Steward KF, Webb K et al. Genomic evidence for the evolution of Streptococcus equi: host restriction, increased virulence, and genetic exchange with human pathogens. PLoS Pathog 2009;5:e1000346 [CrossRef][PubMed]
    [Google Scholar]
  14. Lannergård J, Frykberg L, Guss B. CNE, a collagen-binding protein of Streptococcus equi. FEMS Microbiol Lett 2003;222:69–74 [CrossRef][PubMed]
    [Google Scholar]
  15. Timoney JF, Qin A, Muthupalani S, Artiushin S. Vaccine potential of novel surface exposed and secreted proteins of Streptococcus equi. Vaccine 2007;25:5583–5590 [CrossRef][PubMed]
    [Google Scholar]
  16. Guss B, Flock M, Frykberg L, Waller AS, Robinson C et al. Getting to grips with strangles: an effective multi-component recombinant vaccine for the protection of horses from Streptococcus equi infection. PLoS Pathog 2009;5:e1000584 [CrossRef][PubMed]
    [Google Scholar]
  17. Ramos JL, Martínez-Bueno M, Molina-Henares AJ, Terán W, Watanabe K et al. The TetR family of transcriptional repressors. Microbiol Mol Biol Rev 2005;69:326–356 [CrossRef][PubMed]
    [Google Scholar]
  18. Cuthbertson L, Nodwell JR. The TetR family of regulators. Microbiol Mol Biol Rev 2013;77:440–475 [CrossRef][PubMed]
    [Google Scholar]
  19. Harris SR, Robinson C, Steward KF, Webb KS, Paillot R et al. Genome specialization and decay of the strangles pathogen, Streptococcus equi, is driven by persistent infection. Genome Res 2015;25:1360–1371 [CrossRef][PubMed]
    [Google Scholar]
  20. Heather Z, Holden MT, Steward KF, Parkhill J, Song L et al. A novel streptococcal integrative conjugative element involved in iron acquisition. Mol Microbiol 2008;70:1274–1292 [CrossRef][PubMed]
    [Google Scholar]
  21. Hamilton A, Robinson C, Sutcliffe IC, Slater J, Maskell DJ et al. Mutation of the maturase lipoprotein attenuates the virulence of Streptococcus equi to a greater extent than does loss of general lipoprotein lipidation. Infect Immun 2006;74:6907–6919 [CrossRef][PubMed]
    [Google Scholar]
  22. Flock M, Karlström A, Lannergård J, Guss B, Flock JI. Protective effect of vaccination with recombinant proteins from Streptococcus equi subspecies equi in a strangles model in the mouse. Vaccine 2006;24:4144–4151 [CrossRef][PubMed]
    [Google Scholar]
  23. Robinson C, Steward KF, Potts N, Barker C, Hammond TA et al. Combining two serological assays optimises sensitivity and specificity for the identification of Streptococcus equi subsp. equi exposure. Vet J 2013;197:188–191 [CrossRef][PubMed]
    [Google Scholar]
  24. Chang C, Huang IH, Hendrickx AP, Ton-That H. Visualization of Gram-positive bacterial pili. Methods Mol Biol 2013;966:77–95 [CrossRef][PubMed]
    [Google Scholar]
  25. Nakata M, Köller T, Moritz K, Ribardo D, Jonas L et al. Mode of expression and functional characterization of FCT-3 pilus region-encoded proteins in Streptococcus pyogenes serotype M49. Infect Immun 2009;77:32–44 [CrossRef][PubMed]
    [Google Scholar]
  26. Manetti AG, Köller T, Becherelli M, Buccato S, Kreikemeyer B et al. Environmental acidification drives S. pyogenes pilus expression and microcolony formation on epithelial cells in a FCT-dependent manner. PLoS One 2010;5:e13864 [CrossRef][PubMed]
    [Google Scholar]
  27. Pancotto L, de Angelis G, Bizzarri E, Barocchi MA, del Giudice G et al. Expression of the Streptococcus pneumoniae pilus-1 undergoes on and off switching during colonization in mice. Sci Rep 2013;3:2040 [CrossRef][PubMed]
    [Google Scholar]
  28. Abbot EL, Smith WD, Siou GP, Chiriboga C, Smith RJ et al. Pili mediate specific adhesion of Streptococcus pyogenes to human tonsil and skin. Cell Microbiol 2007;9:1822–1833 [CrossRef][PubMed]
    [Google Scholar]
  29. Lindberg F, Lund B, Normark S. Gene products specifying adhesion of uropathogenic Escherichia coli are minor components of pili. Proc Natl Acad Sci USA 1986;83:1891–1895 [CrossRef][PubMed]
    [Google Scholar]
  30. Konto-Ghiorghi Y, Mairey E, Mallet A, Duménil G, Caliot E et al. Dual role for pilus in adherence to epithelial cells and biofilm formation in Streptococcus agalactiae. PLoS Pathog 2009;5:e1000422 [CrossRef][PubMed]
    [Google Scholar]
  31. Lauer P, Rinaudo CD, Soriani M, Margarit I, Maione D et al. Genome analysis reveals pili in group B Streptococcus. Science 2005;309:105 [CrossRef][PubMed]
    [Google Scholar]
  32. Cho KH, Caparon MG. Patterns of virulence gene expression differ between biofilm and tissue communities of Streptococcus pyogenes. Mol Microbiol 2005;57:1545–1556 [CrossRef][PubMed]
    [Google Scholar]
  33. Lembke C, Podbielski A, Hidalgo-Grass C, Jonas L, Hanski E et al. Characterization of biofilm formation by clinically relevant serotypes of group A streptococci. Appl Environ Microbiol 2006;72:2864–2875 [CrossRef][PubMed]
    [Google Scholar]
  34. Rinaudo CD, Rosini R, Galeotti CL, Berti F, Necchi F et al. Specific involvement of pilus type 2a in biofilm formation in group B Streptococcus. PLoS One 2010;5:e9216 [CrossRef][PubMed]
    [Google Scholar]
  35. Frick IM, Mörgelin M, Björck L. Virulent aggregates of Streptococcus pyogenes are generated by homophilic protein-protein interactions. Mol Microbiol 2000;37:1232–1247 [CrossRef][PubMed]
    [Google Scholar]
  36. Rosch JW, Mann B, Thornton J, Sublett J, Tuomanen E. Convergence of regulatory networks on the pilus locus of Streptococcus pneumoniae. Infect Immun 2008;76:3187–3196 [CrossRef][PubMed]
    [Google Scholar]
  37. Jiang S, Park SE, Yadav P, Paoletti LC, Wessels MR. Regulation and function of pilus island 1 in group B Streptococcus. J Bacteriol 2012;194:2479–2490 [CrossRef][PubMed]
    [Google Scholar]
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