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Impact of D-amino acid dehydrogenase on virulence factor production by a Pseudomonas aeruginosa

Kathryn E Oliver1, Laura Silo-Suh

  • 1a Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA.

Canadian Journal of Microbiology
|September 10, 2013
PubMed

Insights

D-amino acid dehydrogenase (DadA) is crucial for Pseudomonas aeruginosa virulence in cystic fibrosis (CF) lungs. This enzyme supports the production of key toxins, biofilm formation, and overall infection severity.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Biochemistry

Background:

  • Chronic Pseudomonas aeruginosa infections are the primary cause of mortality in cystic fibrosis (CF) patients.
  • P. aeruginosa employs unique strategies to thrive as the dominant pathogen in the CF lung environment.
  • The D-amino acid dehydrogenase (dadA) gene is highly expressed in P. aeruginosa within CF lungs.

Purpose of the Study:

  • To investigate the role of the dad operon in Pseudomonas aeruginosa virulence factor production.
  • To understand the physiological significance of D-amino acid dehydrogenase (DadA) in P. aeruginosa.

Main Methods:

  • Characterization of the dad operon's contribution to virulence factor production.
  • Assessment of DadA's role in pyocyanin, pyoverdine, and rhamnolipid production.
  • Evaluation of DadA's impact on alginate production, biofilm formation, and virulence in a CF-adapted P. aeruginosa isolate using an alfalfa seedling model.

Main Results:

  • DadA is essential for optimal production of pyocyanin, pyoverdine, and rhamnolipid in both CF-adapted and non-CF-adapted P. aeruginosa isolates.
  • DadA is required for enhanced alginate production and biofilm formation in CF-adapted P. aeruginosa.
  • DadA significantly contributes to the virulence of CF-adapted P. aeruginosa in a plant-based infection model.

Conclusions:

  • D-amino acid dehydrogenase (DadA) plays a multifaceted role in the production of critical virulence factors by Pseudomonas aeruginosa.
  • DadA influences the production of toxins, exopolysaccharides, and biofilm formation, impacting P. aeruginosa's pathogenicity in CF.

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