Theophylline as a quorum sensing and biofilm inhibitor in Pseudomonas aeruginosa and Chromobacterium violaceum

Int Microbiol. 2024 Oct;27(5):1457-1471. doi: 10.1007/s10123-024-00487-w. Epub 2024 Feb 12.

Abstract

Quorum sensing (QS) is pivotal in coordinating virulence factors and biofilm formation in various pathogenic bacteria, making it a prime target for disrupting bacterial communication. Pseudomonas aeruginosa is a member of the "ESKAPE" group of bacterial pathogens known for their association with antimicrobial resistance and biofilm formation. The current antibiotic arsenal falls short of addressing biofilm-related infections effectively, highlighting the urgent need for novel therapeutic agents. In this study, we explored the anti-QS and anti-biofilm properties of theophylline against two significant pathogens, Chromobacterium violaceum and P. aeruginosa. The production of violacein, pyocyanin, rhamnolipid, and protease was carried out, along with the evaluation of biofilm formation through methods including crystal violet staining, triphenyl tetrazolium chloride assay, and fluorescence microscopy. Furthermore, computational analyses were conducted to predict the targets of theophylline in the QS pathways of P. aeruginosa and C. violaceum. Our study demonstrated that theophylline effectively inhibits QS activity and biofilm formation in C. violaceum and P. aeruginosa. In P. aeruginosa, theophylline inhibited the production of key virulence factors, including pyocyanin, rhamnolipid, protease, and biofilm formation. The computational analyses suggest that theophylline exhibits robust binding affinity to CviR in C. violaceum and RhlR in P. aeruginosa, key participants in the QS-mediated biofilm pathways. Furthermore, theophylline also displays promising interactions with LasR and QscR in P. aeruginosa. Our study highlights theophylline as a versatile anti-QS agent and offers a promising avenue for future research to develop novel therapeutic strategies against biofilm-associated infections.

Keywords: Chromobacterium violaceum; Pseudomonas aeruginosa; Biofilm; CviR; QS; Theophylline.

MeSH terms

  • Anti-Bacterial Agents* / pharmacology
  • Bacterial Proteins / metabolism
  • Biofilms* / drug effects
  • Biofilms* / growth & development
  • Chromobacterium* / drug effects
  • Chromobacterium* / metabolism
  • Chromobacterium* / physiology
  • Glycolipids / metabolism
  • Glycolipids / pharmacology
  • Indoles / metabolism
  • Indoles / pharmacology
  • Microbial Sensitivity Tests
  • Pseudomonas aeruginosa* / drug effects
  • Pseudomonas aeruginosa* / metabolism
  • Pseudomonas aeruginosa* / physiology
  • Pyocyanine* / biosynthesis
  • Pyocyanine* / metabolism
  • Quorum Sensing* / drug effects
  • Theophylline* / metabolism
  • Theophylline* / pharmacology
  • Virulence Factors* / metabolism

Substances

  • Anti-Bacterial Agents
  • Theophylline
  • Virulence Factors
  • Pyocyanine
  • rhamnolipid
  • Indoles
  • Glycolipids
  • violacein
  • Bacterial Proteins

Supplementary concepts

  • Chromobacterium violaceum