Related Experiment Video

Updated: Jul 20, 2026

Modeling Persistent Pseudomonas aeruginosa Infection in Wounded Zebrafish Larvae
06:04

Modeling Persistent Pseudomonas aeruginosa Infection in Wounded Zebrafish Larvae

Published on: June 13, 2025

Contribution of quorum-sensing systems to virulence of Pseudomonas aeruginosa in an experimental pyelonephritis model

Rahul Mittal1, Saroj Sharma, Sanjay Chhibber

  • 1Department of Microbiology, Panjab University, Chandigarh, India. rahul_mittal20022@yahoo.com

Journal of Microbiology, Immunology, and Infection = Wei Mian Yu Gan Ran Za Zhi
|August 24, 2006
PubMed
Abstract

Insights

Quorum-sensing systems are crucial for Pseudomonas aeruginosa virulence in pyelonephritis. Disrupting these systems significantly reduces bacterial pathogenicity and infection severity in mice.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Molecular Biology

Background:

  • Pseudomonas aeruginosa utilizes quorum-sensing (QS) systems to regulate virulence factors.
  • QS mechanisms involve autoinducer molecules to monitor cell density.
  • This study investigates the role of QS in P. aeruginosa-induced pyelonephritis.

Purpose of the Study:

  • To determine the contribution of quorum-sensing signals to P. aeruginosa pathogenicity in a murine pyelonephritis model.
  • To assess the role of specific QS systems (las and rhl) in virulence.

Main Methods:

  • Utilized wild-type P. aeruginosa (PAO1) and isogenic mutants (PAO-JP1, PAO-JP3) with disrupted las and rhl QS systems.
  • Included a clinical uroisolate of P. aeruginosa deficient in QS signals.
  • Assessed virulence through neutrophil influx, malondialdehyde production, bacterial load, and renal pathology in mice.

Main Results:

  • The wild-type P. aeruginosa strain exhibited significantly higher virulence than QS mutant strains.
  • QS-deficient strains showed reduced neutrophil influx, malondialdehyde production, and renal bacterial load.
  • Pathological damage in the kidneys was less severe with QS-deficient strains.

Conclusions:

  • Quorum-sensing systems are essential for P. aeruginosa virulence during pyelonephritis.
  • Both the las and rhl QS systems play critical roles in the development of P. aeruginosa pyelonephritis.
  • Targeting QS mechanisms could be a potential therapeutic strategy.

More Related Videos

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds07:13

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds

Published on: August 8, 2025

Related Concept Videos

Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Bacterial Signaling01:30

Bacterial Signaling

Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
Determinants of Bacterial Pathogenicity and Virulence01:20

Determinants of Bacterial Pathogenicity and Virulence

Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...