Quorum Quenching by Endophytic Bacillus cereus AL1: A Lactonase-Based Anti-Virulence Strategy Against Pseudomonas aeruginosa

Strategic Insights -

Researchers at Future University in Egypt have isolated an endophytic bacterium, Bacillus cereus AL1, which exhibits significant anti-virulence activity against Pseudomonas aeruginosa. The study, published in BMC Microbiology, highlights the potential of Bacillus cereus AL1 lactonase as an effective anti-virulence agent against Pseudomonas aeruginosa without the pressure for resistance development. The research team found that the partially purified lactonase enzyme from Bacillus cereus AL1 isolate exhibited significant anti-virulence activity, reducing biofilm formation, swarming motility, and pyocyanin production against Pseudomonas aeruginosa PAO1 and clinical Pseudomonas aeruginosa isolates.

Key Takeaways:

  • Bacillus cereus AL1, an endophytic bacterium, exhibits significant anti-virulence activity against Pseudomonas aeruginosa.
  • The partially purified lactonase enzyme from Bacillus cereus AL1 isolate reduced biofilm formation, swarming motility, and pyocyanin production against Pseudomonas aeruginosa PAO1 and clinical Pseudomonas aeruginosa isolates.
  • The study highlights the potential of Bacillus cereus AL1 lactonase as an effective anti-virulence agent against Pseudomonas aeruginosa without the pressure for resistance development.
  • The quorum quenching activity of Bacillus cereus AL1 lactonase provided protection in a Galleria mellonella infection model.
  • The study was conducted at Future University in Egypt and published in BMC Microbiology.

Statistics:

  • 52 bacterial isolates were isolated from ten plants.
  • 11 endophytes and 1 epiphyte isolate showed the aiiA gene encoding lactonase enzyme.
  • 9 endophyte isolates showed complete degradation (100%) of the quorum sensing signal molecule N-hexanoyl-L-homoserine lactone.
  • Sequence alignment of the Bacillus cereus AL1 lactonase protein revealed close similarity to the homologous lactonase from Bacillus cereus.

Sources:

  • Quorum quenching by endophytic Bacillus cereus AL1: a lactonase-based anti-virulence strategy against Pseudomonas aeruginosa. BMC Microbiology, 2025;25(1):669.
  • Future University in Egypt, Cairo, Egypt. (BioMed Central - www.biomedcentral.com/; BMC Microbiology - www.biomedcentral.com/bmcmicrobiol/)
  • Alaa A. Fawzy, Dept. of Microbiology and Immunology, Faculty of Pharmacy, Future University in Egypt, Cairo, Egypt.
  • Marwa M. Raafat, R. Mahmoud, and Omneya M. Helmy, additional authors of the research.