1887

Abstract

The recently described type III secretion system (TTSS) of subsp. has been linked to virulence in salmonids. In this study, three TTSS effector genes, , or , were inactivated by deletion, as was , the gene encoding the outer-membrane pore of the secretion apparatus. Effects on virulence were assayed by live challenge of Atlantic salmon (). The Δ mutant strain was avirulent by both intraperitoneal (i.p.) injection and immersion, did not appear to establish a clinically inapparent infection and did not confer protection from subsequent rechallenge with the parental strain. H NMR spectroscopy-based metabolite profiling of plasma from all fish showed significant differences in the metabolite profiles between the animals exposed to the parental strain or Δ. The experimental infection by immersion with Δ was indistinguishable from that of the parental strain, that of Δ was delayed, whilst the virulence of Δ was reduced significantly but not abolished. By i.p. injection, Δ, Δ and Δ caused an experimental disease indistinguishable from that of the parental strain. These data demonstrate that while the TTSS is absolutely essential for virulence of subsp. in Atlantic salmon, removal of individual effectors has little influence on virulence but has a significant effect on colonization. The Δ i.p. injection data also suggest that in addition to host invasion there is a second step in pathogenesis that requires an active TTSS.

Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.28768-0
2006-06-01
2024-04-19
Loading full text...

Full text loading...

/deliver/fulltext/micro/152/6/1847.html?itemId=/content/journal/micro/10.1099/mic.0.28768-0&mimeType=html&fmt=ahah

References

  1. Aepfelbacher M. 2004; Modulation of Rho GTPases by type III secretion system translocated effectors of Yersinia . Rev Physiol Biochem Pharmacol 152:65–77
    [Google Scholar]
  2. Aries E. R, Lidiard P. D, Spragg A. R. 1991; Principal components analysis. Chem Br 27:821–824
    [Google Scholar]
  3. Ausubel F. M, Brent R, Kingston R. E, Moore D. D, Seidman J. G, Smith J. A, Struhl K. 1998 Current Protocols in Molecular Biology New York: Wiley;
    [Google Scholar]
  4. Barnes A. C, Horne M. T, Ellis A. E. 1996; Effect of iron on expression of superoxide dismutase by Aeromonas salmonicida and associated resistance to superoxide anion. FEMS Microbiol Lett 142:19–26 [CrossRef]
    [Google Scholar]
  5. Bernoth E.-M. 1997; Diagnosis of furunculosis: the tools. In Furunculosis: Multidisciplinary Fish Disease Research pp  54–97 Edited by Bernoth E.-M., Ellis A. E., Midtlyng P. J., Olivier G., Smith P. London: Academic Press;
    [Google Scholar]
  6. Braun M, Stuber K, Schlatter Y, Wahli T, Kuhnert P, Frey J. 2002; Characterization of an ADP-ribosyltransferase toxin (AexT) from Aeromonas salmonicida subsp. salmonicida . J Bacteriol 184:1851–1858 [CrossRef]
    [Google Scholar]
  7. Burr S. E, Stuber K, Wahli T, Frey J. 2002; Evidence for a type III secretion system in Aeromonas salmonicida subsp. salmonicida . J Bacteriol 184:5966–5970 [CrossRef]
    [Google Scholar]
  8. Burr S. E, Stuber K, Frey J. 2003a; The ADP-ribosylating toxin AexT, from Aeromonas salmonicida subsp. salmonicida is translocated via a Type III secretion pathway. J Bacteriol 185:6583–6591 [CrossRef]
    [Google Scholar]
  9. Burr S. E, Wahli T, Segner H, Pugovkin D, Frey J. 2003b; Association of Type III secretion genes with virulence of Aeromonas salmonicida subsp. salmonicida . Dis Aquat Organ 57:167–171 [CrossRef]
    [Google Scholar]
  10. Burr S. E, Pugovkin D, Wahli T, Segner H, Frey J. 2005; Attenuated virulence of an Aeromonas salmonicida subsp. salmonicida type III secretion mutant in a rainbow trout model. Microbiology 151:2111–2118 [CrossRef]
    [Google Scholar]
  11. Cardella M. A, Eimers M. E. 1990; Safety and potency testing of federally licensed fish bacterins. J Aquat Anim Health 2:49–55 [CrossRef]
    [Google Scholar]
  12. Cornelis G. R, Wolf-Hanz H. 1997; The Yersinia Yop virulon: a bacterial system for subverting eukaryotic cells. Mol Microbiol 23:861–867 [CrossRef]
    [Google Scholar]
  13. Dacanay A, Johnson S. C, Bjornsdottir R, Ross N. W, Reith M, Singh R. K, Brown L. L. 2003; Molecular characterization and quantitative analysis of superoxide dismutases in virulent and avirulent strains of Aeromonas salmonicida subsp. salmonicida . J Bacteriol 185:4335–4344
    [Google Scholar]
  14. Ebanks R. O, Dacanay A, Pinto D, Goguen M, Ross N. W. 2004; Differential proteomic analysis of Aeromonas salmonicida outer membrane proteins in response to low-iron and in vivo growth conditions. Proteomics 4:1074–1085 [CrossRef]
    [Google Scholar]
  15. Ellis A. E, Burrows A. S, Stapleton K. J. 1988; Lack of relationship between virulence of Aeromonas salmonicida and the putative virulence factors: A-layer, extracellular proteases and extracellular haemolysins. J Fish Dis 11:309–323 [CrossRef]
    [Google Scholar]
  16. Eriksson L, Johansson E, Kettaneh N, Wold S. 1999 Introduction to Multi and Megavariate Data Analysis Using Projection Methods (PCA & PLS) Umea, Sweden: Umetrics;
    [Google Scholar]
  17. Fernandez A. I, Fernandez A. F, Perez M. J, Nieto T. P, Ellis A. E. 1998; Siderophore production by Aeromonas salmonicida subsp. salmonicida . Lack of strain specificity. Dis Aquat Organ 33:87–92 [CrossRef]
    [Google Scholar]
  18. Garduño R. A, Kuzyk M. A, Kay W. W. 1997; Structural and physiological determinants of resistance of Aeromonas salmonicida to reactive radicals. Can J Microbiol 43:1044–1053 [CrossRef]
    [Google Scholar]
  19. Garduño R. A, Lizama A. L, Moore A. R, Olivier G, Kay W. W, Garduño E. 2000; Co-culture of Aeromonas salmonicida and host cells in intraperitoneal implants is associated with enhanced bacterial survival. Can J Microbiol 46:674–678 [CrossRef]
    [Google Scholar]
  20. Gophna U, Ron E. Z, Graur D. 2003; Bacterial type III secretion systems are ancient and evolved by multiple horizontal-transfer events. Gene 312:151–163 [CrossRef]
    [Google Scholar]
  21. Hall T. A. 1999; BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symp Ser 41:95–98
    [Google Scholar]
  22. Hiney M, Smith P, Bernoth E.-M. 1997; Covert A. salmonicida infections. In Furunculosis: Multidisciplinary Fish Disease Research pp  54–97 Edited by Bernoth E.-M., Ellis A. E., Midtlyng P. J., Olivier G., Smith P. London: Academic Press;
    [Google Scholar]
  23. Hueck C. J. 1998; Type III protein secretion systems in bacterial pathogens of animal and plants. Microbiol Mol Biol Rev 62:379–433
    [Google Scholar]
  24. Koster M, Bitter W, Allaoui A, Cornelis G. R, Tommassen J, de Cock H. 1997; The outer membrane component, YscC, of the Yop secretion machinery of Yersinia enterocolitica forms a ring-shaped multimeric complex. Mol Microbiol 26:789–797 [CrossRef]
    [Google Scholar]
  25. Link A. J, Phillips D, Church G. M. 1997; Methods for generating precise deletions and insertions in the genome of wild-type Escherichia coli : application to open reading frame characterization. J Bacteriol 179:6228–6237
    [Google Scholar]
  26. Logsdon L. K, Mecsas J. 2003; Requirement of the Yersinia pseudotuberculosis effectors YopH and YopE in colonization and persistence in intestinal and lymph tissues. Infect Immun 71:4595–5607 [CrossRef]
    [Google Scholar]
  27. Metcalf W. W, Jiang W, Wanner B. L. 1994; Use of the rep technique for allele replacement to construct new Escherichia coli hosts for maintenance of R6K gamma origin plasmids at different copy numbers. Gene 138:1–7 [CrossRef]
    [Google Scholar]
  28. Metcalf W. W, Jiang W, Daniels L. L, Kim S. K, Haldimann A, Wanner B. L. 1996; Conditionally replicative and conjugative plasmids carrying lacZ alpha for cloning, mutagenesis, and allele replacement in bacteria. Plasmid 35:1–13 [CrossRef]
    [Google Scholar]
  29. Nordmo R, Ramsted A. 1997; Comparison of different challenge methods to evaluate the efficacy of furunculosis vaccines in Atlantic salmon Salmo salar L. J Fish Dis 20:119–126 [CrossRef]
    [Google Scholar]
  30. Olivier G. 1990; Virulence of Aeromonas salmonicida : lack of relationship with phenotypic characteristics. J Aquat Anim Health 2:119–127 [CrossRef]
    [Google Scholar]
  31. Olivier G, Moore R. A, Fildes J. 1992; Toxicity of Aeromonas salmonicida cells to Atlantic salmon Salmo salar peritoneal macrophages. Dev Comp Immunol 16:49–61 [CrossRef]
    [Google Scholar]
  32. Plano G. V, Straley S. C. 1995; Mutations in yscC , yscD , and yscG prevent high-level expression and secretion of V antigen and Yops in Yersinia pestis . J Bacteriol 177:3843–3854
    [Google Scholar]
  33. Roberts R. J, Rodger H. J. 2001; The pathophysiology and systemic pathology of teleosts. In Fish Pathology, 3rd edn. pp  55–133 Edited by Roberts R. J. London: W. B. Saunders;
    [Google Scholar]
  34. Salte R, Norberg K, Arnesen J. A, Oedegaard O. R, Eggset G. 1992; Serine protease and glycerophospholipid : cholesterol acyltransferase of Aeromonas salmonicida work in concert in thrombus formation; in vitro the process is counteracted by plasma antithrombin and α [sub]2[/sub]-macroglobulin. J Fish Dis 15:215–227 [CrossRef]
    [Google Scholar]
  35. Schotts E. B. 1994; Furunculosis. In Suggested Procedures for the Detection and Identification of Certain Finfish and Shellfish Pathogens, 4th edn. version 1, chapter 9 Edited by Thoesen J. C. Bethesda, MD: Fish Health Section, American Fisheries Society;
    [Google Scholar]
  36. Solanky K. S, Burton I. W, MacKinnon S. L, Walter J. A, Dacanay A. 2005; Metabolic changes in Atlantic salmon exposed to Aeromonas salmonicida detected by [sup]1[/sup]H-nuclear magnetic resonance spectroscopy of plasma. Dis Aquat Organ 65:107–114 [CrossRef]
    [Google Scholar]
  37. Specker J. L, Portesi D. M, Cornell S. C, Veillette P. A. 1994; Methodology for implanting cortisol in Atlantic salmon and effects of chronically elevated cortisol on osmoregulatory physiology. Aquaculture 121:181–193 [CrossRef]
    [Google Scholar]
  38. Stuber K, Burr S. E, Braun M, Wahli T, Frey J. 2003; Type III secretion genes in Aeromonas salmonicida subsp. salmonicida are located on a large thermolabile virulence plasmid. J Clin Microbiol 41:3854–3856 [CrossRef]
    [Google Scholar]
  39. Trülzsch K, Sporleder T, Igwe E. I, Heesemann J, Rüssmann H. 2004; Contribution of the major secreted Yops of Yersinia enterocolitica O : 8 to pathogenicity in the mouse infection model. Infect Immun 72:5227–5234 [CrossRef]
    [Google Scholar]
  40. Trust T. J, Ishiguro E. E, Chart H, Kay W. W. 1983; Virulence properties of Aeromonas salmonicida . J World Maricult Soc 14:193–200
    [Google Scholar]
  41. Vipond R, Bricknell I. R, Durant E, Bowden T. J, Ellis A. E, Smith M, MacIntyre S. 1998; Defined deletion mutants demonstrate that the major secreted toxins are not essential for the virulence of Aeromonas salmonicida . Infect Immun 66:1990–1998
    [Google Scholar]
  42. Yu H. B, Srinivasa Rao P. S, Lee H. C, Vilches S, Merino S, Tomas J. M, Leung K. Y. 2004; A Type III secretion system is required for Aeromonas hydrophila AH-1 pathogenesis. Infect Immun 72:1248–1256 [CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.28768-0
Loading
/content/journal/micro/10.1099/mic.0.28768-0
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error