Related Experiment Video
Updated: Jun 15, 2025
Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases
Published on: January 1, 2016
Bacterial outer membrane vesicles increase polymyxin resistance in Pseudomonas aeruginosa while inhibiting its quorum
Zhihui Chen1, Yucheng Liu1, Lan Jiang1
1College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
Abstract:
The persistent emergence of multidrug-resistant bacterial pathogens is leading to a decline in the therapeutic efficacy of antibiotics, with Pseudomonas aeruginosa (P. aeruginosa) emerging as a notable threat. We investigated the antibiotic resistance and quorum sensing (QS) system of P. aeruginosa, with a particular focused on outer membrane vesicles (OMVs) and polymyxin B as the last line of antibiotic defense. Our findings indicate that OMVs increase the resistance of P. aeruginosa to polymyxin B. The overall gene transcription levels within P. aeruginosa also reveal that OMVs can reduce the efficacy of polymyxin B. However, both OMVs and sublethal concentrations of polymyxin B suppressed the transcription levels of genes associated with the QS system. Furthermore, OMVs and polymyxin B acted in concert on the QS system of P. aeruginosa to produce a more potent inhibitory effect. This suppression was evidenced by a decrease in the secretion of virulence factors, impaired bacterial motility, and a notable decline in the ability to form biofilms. These results reveal that OMVs enhance the resistance of P. aeruginosa to polymyxin B, yet they collaborate with polymyxin B to inhibit the QS system. Our research contribute to a deeper understanding of the resistance mechanisms of P. aeruginosa in the environment, and provide new insights into the reduction of bacterial infections caused by P. aeruginosa through the QS system.
Insights
Outer membrane vesicles (OMVs) enhance Pseudomonas aeruginosa resistance to polymyxin B. However, OMVs and polymyxin B together effectively inhibit the bacteria's quorum sensing system, reducing virulence.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Antimicrobial Resistance
Background:
- Multidrug-resistant bacteria, particularly Pseudomonas aeruginosa, pose a significant threat due to declining antibiotic efficacy.
- Polymyxin B represents a last-resort antibiotic, but its effectiveness is challenged by resistance mechanisms.
Purpose of the Study:
- To investigate the role of outer membrane vesicles (OMVs) in Pseudomonas aeruginosa antibiotic resistance and quorum sensing (QS).
- To explore the combined effects of OMVs and polymyxin B on P. aeruginosa QS and virulence.
Main Methods:
- Analysis of P. aeruginosa gene transcription levels in response to OMVs and polymyxin B.
- Assessment of virulence factor secretion, bacterial motility, and biofilm formation.
- Evaluation of the impact of OMVs and polymyxin B on the QS system.
Main Results:
- OMVs were found to increase P. aeruginosa resistance to polymyxin B.
- Both OMVs and sublethal polymyxin B suppressed QS-related gene transcription.
- OMVs and polymyxin B synergistically inhibited the QS system, leading to reduced virulence factors, motility, and biofilm formation.
Conclusions:
- OMVs enhance P. aeruginosa polymyxin B resistance but collaborate with the antibiotic to inhibit the QS system.
- Targeting the QS system offers a potential strategy to combat P. aeruginosa infections.
- Understanding these interactions provides insights into bacterial resistance and infection control.
Related Concept Videos
01:30Bacterial Signaling
01:18Surface Membrane Barriers
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...