| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Pathogenicity and Medical Microbiology |
Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore1192601
Author for correspondence: K. Y. Leung. Tel: +65 8747835. Fax: +65 7792486. e-mail: dbslky{at}nus.edu.sg
Edwardsiella tarda is a Gram-negative bacterium that causes a systemic infection, edwardsiellosis, in fish. The virulence factors of this pathogen and its genetic determinants have not been systematically examined. In this study, TnphoA transposon mutagenesis was used to construct a library of 440 alkaline phosphatase (PhoA+) fusion mutants from a total of 400000 transconjugants derived from Ed. tarda PPD130/91. This library included genes for secreted and membrane-associated proteins normally involved in virulence. The library was screened for four virulence factors: siderophore production, motility, serum resistance and catalase production. Eight mutants deficient in one or more of these phenotypes were grouped into four classes. They were further characterized for their stimulation of reactive oxygen intermediate production by fish phagocytes, for their adhesion to and internalization into EPC (epithelioma papillosum of carp) cells, and for attenuation of virulence in blue gourami. Mutants 2A and 34 were highly attenuated in fish, with LD50 values about 10 times higher than for the wild-type. These strains had mutations in the genes encoding arylsulfate sulfotransferase (mutant 2A) and a catalase precursor protein (mutant 34). One hyperinvasive/adhesive mutant and four pst mutants that were pleiotropic and slightly attenuated in fish were also isolated.
|
Abbreviations: CAS, chrome azurol S; EPC, epithelioma papillosum of carp; ROI, reactive oxygen intermediates
The GenBank accession numbers for the sequences determined in this work are AF324338–AF324342 (Table 3).
This article has been cited by other articles:
|
|
 |
|
  G. A. O'May, S. M. Jacobsen, M. Longwell, P. Stoodley, H. L. T. Mobley, and M. E. Shirtliff The high-affinity phosphate transporter Pst in Proteus mirabilis HI4320 and its importance in biofilm formation Microbiology, May 1, 2009; 155(5): 1523 - 1535. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Verjan, I. Hirono, and T. Aoki Genetic Loci of Major Antigenic Protein Genes of Edwardsiella tarda Appl. Envir. Microbiol., September 1, 2005; 71(9): 5654 - 5658. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. J. Runyen-Janecky, A. M. Boyle, A. Kizzee, L. Liefer, and S. M. Payne Role of the Pst System in Plaque Formation by the Intracellular Pathogen Shigella flexneri Infect. Immun., March 1, 2005; 73(3): 1404 - 1410. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. S. Srinivasa Rao, Y. Yamada, and K. Y. Leung A major catalase (KatB) that is required for resistance to H2O2 and phagocyte-mediated killing in Edwardsiella tarda Microbiology, September 1, 2003; 149(9): 2635 - 2644. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. S. Srinivasa Rao, T. M. Lim, and K. Y. Leung Functional Genomics Approach to the Identification of Virulence Genes Involved in Edwardsiella tarda Pathogenesis Infect. Immun., March 1, 2003; 71(3): 1343 - 1351. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. P. Tan, Q. Lin, X. H. Wang, S. Joshi, C. L. Hew, and K. Y. Leung Comparative Proteomic Analysis of Extracellular Proteins of Edwardsiella tarda Infect. Immun., November 1, 2002; 70(11): 6475 - 6480. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |
