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Pseudomonas aeruginosa virulence analyzed in a Dictyostelium discoideum model of infection

Pseudomonas aeruginosa virulence analyzed in a Dictyostelium discoideum model of infection
chair:

Zimmermann, A. / Nuori, B. / Neidig, A. / Häußler, S. / Matz, C. / Overhage, J. (2011)

place:

VAAM 2011, Karlsruhe, Deutschland, 3.-6. April, 2011

 

Date: 2011

Zimmermann, A. / Nuori, B. / Neidig, A. / Häußler, S. / Matz, C. / Overhage, J. (2011): „Pseudomonas aeruginosa virulence analyzed in a Dictyostelium discoideum model of infection“ In: VAAM 2011, Karlsruhe, Deutschland, 3.-6. April, 2011

Abstract

Pseudomonas aeruginosa is a major opportunistic human pathogen which produces a large variety of secreted and cell-associated virulence factors. Since P. aeruginosa infections are difficult to treat due to the emergence of highly antibiotic resistant strains, alternative drug targets including virulence factors are currently being under investigation.

Recently, it has been shown that P. aeruginosa uses similar virulence factors when infecting mammalian systems or non-mammalian hosts like the social amoeba Dictyostelium discoideum, the nematode Caenorhabditis elegans or the fruit fly Drosophila melanogaster (1,2). In this study, we used a comprehensive P. aeruginosa PA14 transposon mutant library to screen for mutants with reduced virulence towards D. discoideum.

A total of 198 P. aeruginosa PA14 transposon mutants were identified to have decreased virulence in this host model system. In addition to mutants with insertions in the type III secretion system (TTSS), we identified genes involved in type IV pili biosynthesis and function, PQS production, tryptophan synthesis, transport, central and amino acid metabolism and gene regulation including quorum sensing, global regulators and two-component regulatory systems.

FACS analyses using a gfp-exoT reporter construct revealed reduced TTSS activity in several studied mutants including type IV pili, PQS biosynthesis and cbrAB, a two-component regulatory system involved in nitrogen and carbon metabolism. Microarray analyses were performed to gain a deeper insight into the interaction of P. aeruginosa with D. discoideum.