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The Deciphering of Growth-Dependent Strategies for Quorum-Sensing Networks in Pseudomonas aeruginosa

Tereza Juříková1, Hynek Mácha1,2, Vanda Lupjanová1

  • 1Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic.

Microorganisms
|September 28, 2023
PubMed

Insights

This study reveals how Pseudomonas aeruginosa quorum sensing (QS) molecules change during biofilm formation and co-infection with Aspergillus fumigatus, identifying potential biomarkers for virulence and inter-microbial interactions.

Area of Science:

  • Microbiology
  • Medical Mycology
  • Bacterial Pathogenesis

Background:

  • * *Pseudomonas aeruginosa* is a major nosocomial pathogen contributing to significant morbidity and mortality.
  • * *P. aeruginosa* frequently co-infects with *Aspergillus fumigatus*, particularly in respiratory infections, influencing disease progression.
  • * Quorum sensing (QS) molecules regulate virulence factors and biofilm formation in *P. aeruginosa*.

Purpose of the Study:

  • * To quantify the levels of various QS molecules produced by *P. aeruginosa* in monoculture and co-culture with *A. fumigatus*.
  • * To investigate the role of QS molecules as potential biomarkers for virulence and biofilm formation.
  • * To elucidate the interaction strategies between *P. aeruginosa* and *A. fumigatus*.

Main Methods:

  • * Quantitative analysis of QS molecules (3-o-C12-HSL, 3-o-C8-HSL, C4-HSL, C6-HSL, HHQ, PQS, PYO) using mass spectrometry.
  • * Scanning electron microscopy (SEM) to visualize *P. aeruginosa* biofilm morphology.
  • * Quantitative PCR (qPCR) to determine genome equivalents of both microorganisms in co-culture.

Main Results:

  • * Distinct quantitative profiles of QS molecules were observed during the transition from planktonic to sessile growth in *P. aeruginosa* monoculture.
  • * Co-culture with *A. fumigatus* altered the QS profile, with reduced abundance of some molecules and increased 3-o-C12-HSL.
  • * SEM revealed characteristic biofilm developmental stages (aggregation, maturation, dispersion), and qPCR indicated synergistic interplay rather than antagonism between the microbes.

Conclusions:

  • * This study provides the first quantitative demonstration of growth-dependent QS molecule secretion in *P. aeruginosa* monoculture and co-culture with *A. fumigatus*.
  • * QS molecule profiles can serve as potential biomarkers for bacterial metabolic states and inter-species interactions.
  • * *P. aeruginosa* and *A. fumigatus* exhibit a cooperative interaction strategy, impacting biofilm dynamics and virulence.
Keywords:
Aspergillus fumigatusPseudomonas aeruginosaQS systembiofilmmetabolomic analysismicrobial interactionplanktonic cell

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