Both α-haemolysin determinants contribute to full virulence of uropathogenic Escherichia coli strain 536

Gábor Nagy, Artur Altenhoefer, Oliver Knapp, Elke Maier, Ulrich Dobrindt, Gabriele Blum-Oehler, Roland Benz, Levente Emody, Jörg Hacker

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Uropathogenic Escherichia coli strain 536 possesses two intact copies of the α-haemolysin determinant localised on distinct pathogenicity islands. The coding regions of the two hlyCABD operons are conserved; however, upstream sequences are entirely dissimilar. Consequently, expression of the encoded toxin molecules in vitro is highly different. On the other hand, the contribution of the individual determinants to the strain's virulence is the same. Isogenic mutants lacking individual hly determinants have a similar increase in LD50 value in a mouse model of urinary tract infection. Mouse lung toxicity as well as in vitro assays reveals a significant decrease in acute cytotoxicity of both mutants in comparison to the parent wild-type strain; however, the two hly mutants do not significantly differ from each other in these respects. Single channel recordings show no difference in electrophysiological characteristics of the pores formed by the individual HlyA molecules on synthetic planar lipid membranes. Nor do the paralogues have any target cell preference in an in vitro cytotoxicity assay. Our data suggest that the two hly paralogues encode identical toxin functions; however, due to different regulation of expression, they participate at distinct stages of the infectious process. Interestingly, the unrelated uropathogenic E. coli strain J96 shares the same two hly alleles, suggesting that acquisition of the two paralogues accorded a selective evolutionary advantage.

Original languageEnglish
Pages (from-to)2006-2012
Number of pages7
JournalMicrobes and Infection
Volume8
Issue number8
DOIs
Publication statusPublished - Jul 2006

Keywords

  • Cytotoxicity
  • Gene duplication
  • Pore formation
  • Uropathogenic Escherichia coli
  • Virulence regulation
  • α-Haemolysin

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Infectious Diseases

Fingerprint Dive into the research topics of 'Both α-haemolysin determinants contribute to full virulence of uropathogenic Escherichia coli strain 536'. Together they form a unique fingerprint.

  • Cite this

    Nagy, G., Altenhoefer, A., Knapp, O., Maier, E., Dobrindt, U., Blum-Oehler, G., Benz, R., Emody, L., & Hacker, J. (2006). Both α-haemolysin determinants contribute to full virulence of uropathogenic Escherichia coli strain 536. Microbes and Infection, 8(8), 2006-2012. https://doi.org/10.1016/j.micinf.2006.02.029