Related Experiment Video
Updated: Apr 27, 2026

Time-lapse Imaging of Bacterial Swarms and the Collective Stress Response
Published on: May 23, 2020
Correlation between group behavior and quorum sensing in Pseudomonas aeruginosa isolated from patients with
Yong Li1, Hong-Ping Qu1, Jia-Lin Liu1
11 Department of Respiratory Medicine, Luwan Branch of Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China ; 2 Department of Critical Care Medicine, 3 Department of Respiratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
Background:
This study investigated the correlation between the expression of the Las and Rhl quorum-sensing (QS) systems and the communal behavior (motility, biofilm formation, and pyocyanin production) of Pseudomonas aeruginosa (P. aeruginosa) isolated from patients with hospital-acquired pneumonia.
Methods:
We analyzed 138 P. aeruginosa isolates from 48 patients (30 men and 18 women; age 68.18±15.08 years). P. aeruginosa clinical isolates were assessed for Las and Rhl gene expression and bacterial motility, biofilm formation, and pyocyanin production.
Results:
P. aeruginosa swimming, twitching, and swarming motility positively correlated with the expression of LasI, LasR, and RhlI (P<0.05) but not with that of RhlR (P>0.05). At all analyzed time points, a significant positive correlation was found between biofilm formation and the expression of LasI, LasR (P<0.01), and RhlI (P<0.05 for day 1, P<0.01 for days 7 and 14), whereas RhlR expression positively correlated with biofilm formation only on day 14 (P<0.05). On days 1 and 7, positive correlation was observed between pyocyanin production and the levels of LasI and RhlI (P<0.05). In bacterial clearance cases, the expression of QS-related genes and the group behavior of the pathogen did not correlate (P>0.05). However, in cases of persistent P. aeruginosa infection, the changes in LasI and LasR gene expression were positively correlated with those in bacterial motility (P<0.05), and the changes in LasI, LasR, RhlI, and RhlR expression showed a significant positive association with those in biofilm formation (P<0.01).
Conclusions:
In patients with hospital-acquired pneumonia, the expression of the Las and Rhl QS genes was associated with bacterial motility, biofilm formation, and pyocyanin production, suggesting an involvement of the QS genes in the clearance of pathogenic P. aeruginosa in patients.
More Related Videos
07:46Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung
Published on: June 5, 2012
03:53Growing a Cystic Fibrosis-Relevant Polymicrobial Biofilm to Probe Community Phenotypes
Published on: April 19, 2024
Related Concept Videos
Gene Regulation in Microbial Communities: Quorum Sensing
Bacterial Signaling
Atypical Pneumonia
Pneumonia II: Pathophysiology
Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...