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Ethics code: IR.ABZUMS.REC.1398.066
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Aynesazi S, Sharifian P, Tavakoli M, Mohammadzadeh M. Time‑dependent analysis of biofilm‑regulatory gene expression during biofilm maturation in Pseudomonas aeruginosa. aumj 2026; 15 (2) : 2
URL: http://aums.abzums.ac.ir/article-1-1960-en.html
URL: http://aums.abzums.ac.ir/article-1-1960-en.html
1- Department of Microbiology, Faculty of Science, Islamic Azad University, North Tehran Branch, Tehran, Iran
2- Department of Microbiology, Faculty of Medicine, Alborz University of Medical Sciences, Karaj, Iran
3- Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
4- Department of Microbiology, Faculty of Medicine, Alborz University of Medical Sciences, Karaj, Iran ,m.mohammadzadeh84@yahoo.com
2- Department of Microbiology, Faculty of Medicine, Alborz University of Medical Sciences, Karaj, Iran
3- Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
4- Department of Microbiology, Faculty of Medicine, Alborz University of Medical Sciences, Karaj, Iran ,
Abstract: (187 Views)
Introduction: Pseudomonas aeruginosa is an opportunistic pathogen that frequently causes severe healthcare-associated infections, particularly in immunocompromised patients. Biofilm formation is a major virulence factor that contributes to bacterial persistence and increased resistance to antimicrobial agents. This study aimed to evaluate the expression patterns of key biofilm-regulatory genes during different stages of biofilm maturation.
Methods: The standard strain Pseudomonas aeruginosa ATCC 10145 was cultured, and biofilm formation was quantified using a microtiter plate assay. The expression levels of the biofilm-associated regulatory genes lasR, rhlR, gacA, and retS were assessed at multiple time points over a five-day period using quantitative real-time polymerase chain reaction (qRT-PCR). Statistical analyses were performed using GraphPad Prism version 8.0. The study was approved by the Ethics Committee of Alborz University of Medical Sciences (IR.ABZUMS.REC.1398.066) and was conducted in accordance with the principles of the Declaration of Helsinki.
Results: Expression analysis demonstrated a significant time-dependent increase in the expression levels of all investigated genes (lasR, rhlR, gacA, and retS) throughout the biofilm maturation process, from the planktonic phase (day 0) to mature biofilm formation (day 5) (P < 0.0001). The greatest increases were observed for gacA and lasR, with approximately 56-fold and 50-fold upregulation, respectively, compared with baseline expression levels.
Conclusion: The biofilm maturation process in P. aeruginosa is associated with significant upregulation of key regulatory genes involved in quorum sensing and two-component regulatory systems. The observed increase in both activating and inhibitory regulatory genes highlights the complexity of the genetic network governing biofilm development and may provide potential targets for future anti-biofilm therapeutic strategies.
Methods: The standard strain Pseudomonas aeruginosa ATCC 10145 was cultured, and biofilm formation was quantified using a microtiter plate assay. The expression levels of the biofilm-associated regulatory genes lasR, rhlR, gacA, and retS were assessed at multiple time points over a five-day period using quantitative real-time polymerase chain reaction (qRT-PCR). Statistical analyses were performed using GraphPad Prism version 8.0. The study was approved by the Ethics Committee of Alborz University of Medical Sciences (IR.ABZUMS.REC.1398.066) and was conducted in accordance with the principles of the Declaration of Helsinki.
Results: Expression analysis demonstrated a significant time-dependent increase in the expression levels of all investigated genes (lasR, rhlR, gacA, and retS) throughout the biofilm maturation process, from the planktonic phase (day 0) to mature biofilm formation (day 5) (P < 0.0001). The greatest increases were observed for gacA and lasR, with approximately 56-fold and 50-fold upregulation, respectively, compared with baseline expression levels.
Conclusion: The biofilm maturation process in P. aeruginosa is associated with significant upregulation of key regulatory genes involved in quorum sensing and two-component regulatory systems. The observed increase in both activating and inhibitory regulatory genes highlights the complexity of the genetic network governing biofilm development and may provide potential targets for future anti-biofilm therapeutic strategies.
Article number: 2
Keywords: Pseudomonas aeruginosa, Biofilms, Quorum Sensing, Two-Component Regulatory Systems, Gene Expression Regulation, Bacterial, Virulence Factorssensing.
Type of Study: Research |
Subject:
Special
Received: 2025/10/18 | Accepted: 2026/01/19 | Published: 2026/06/06
Received: 2025/10/18 | Accepted: 2026/01/19 | Published: 2026/06/06
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