Dhillon, B.

Häußler, S.

Matz, C.

Neidig, A.

Overhage, J.

Zimmermann, A.

KITopen

KIT – University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association Pseudomonas aeruginosa virulence analyzed in a Dictyostelium discoideum model of infection A. Zimmermann1, A. Neidig2, B. Dhillon3, S. Häussler1, C. Matz1, J. Overhage*1,2  Microarray analysis of P. aeruginosa PA14 –  D. discoideum interaction  Transposon mutants with decreased virulence 1Helmholtz Centre for Infection Research, Braunschweig, Germany; 2Karlsruhe Institute of Technology, Karlsruhe, Germany,  3Simon Fraser University, Vancouver, Canada; *joerg.overhage@kit.edu  Preliminary screening Verification Global screening of a P. aeruginosa PA14  mutant  library  for decreased virulence ~ 6500 Tn-mutants   (M9-medium, 4 days) Identification of mutants with  altered virulence phenotype wildtype Tn-mutant Summary  - ~200 Tn-mutants  - T3SS (9)  - Type IV pili (7)  - Regulators (21)  - Metabolism (45)  - Secondary     metabolites (15)  - Hypothetical (68) wildtype cbrA cbrB trpF trpG pqsE pqsA pilJ pilG pscC exsC pchE pchD 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Minimum number of amoebae producing a halo  (per 5 µl)   PA14 Tn-mutant Pyochelin PQS Tryptophan TCS Type IV pili T3SS Virulence of selected PA14 mutants  Summary - Microarray analysis revealed ~500 genes differentially regulated in    response to D. discoideum.   - Various virulence related genes including secondary metabolites, T6SS,    Type IV pili and extracellular proteases and toxins were highly up-regulated.  - Type IV pili, secondary metabolites (e.g. PQS or pyochelin) and the two-    component system cbrAB which is involved in the regulation of nitrogen/     carbon metabolism are crucial factors for P. aeruginosa to circumvent    protozoan grazing. P. aeruginosa PA14 P. aeruginosa PA14 - D. discoideum - M9 medium - 40 hours  - 23°C 505 Genes up- or down-regulated (>3fold) • 317 up (~105 hypothetical)  • 188 down (~ 97 hypothetical) Basic processes/ Metabolism (62) Genes up-regulated in response to D. discoideum Virulence (48) - PQS, pyochelin - T6SS - Type IV pili - proteaseses,    toxins Transport of small  molecules (36) Others (41) Transcriptional regulators (9) Adaptation/ Protection(16) Acknowledgement The RG „Bacterial Stress Response and Process Engineering“  Is  financed by the German Excellence Initiative Institute of Functional Interfaces IFG Introduction  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 (Hilbi et al., 2007; Alibaud et al., 2008).  In this study, we used a comprehensive P. aeruginosa PA14 transposon mutant library (Liberati et al., 2006) to screen for mutants with reduced virulence.  Furthermore, microarray analyses were performed to gain a deper insight into the interaction of P. aeruginosa with D. discoideum. 

Pseudomonas aeruginosa virulence analyzed in a Dictyostelium discoideum model of infection

https://publikationen.bibliothek.kit.edu/220084240/3815869

Pseudomonas aeruginosa virulence analyzed in a Dictyostelium discoideum model of infection

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