Filamentous Bacteriophage Promote Biofilm Assembly and Function

Area of Science:

• Microbiology
• Biophysics
• Materials Science

Background:

• Bacterial biofilms are communities of microorganisms encased in a self-produced matrix, enabling persistence in challenging environments like cystic fibrosis airways.
• The mechanisms by which bacteria assemble the complex polymer-rich matrix of biofilms remain largely uncharacterized.
• Pseudomonas aeruginosa is a key pathogen in cystic fibrosis, forming persistent biofilms.

Purpose of the Study:

• To elucidate the self-assembly mechanism of the Pseudomonas aeruginosa extracellular matrix.
• To investigate the role of filamentous bacteriophages in biofilm structure and function.
• To explore potential therapeutic strategies targeting biofilm matrix organization.

Main Methods:

• Analysis of extracellular matrix self-assembly in Pseudomonas aeruginosa.
• Investigation of entropic interactions between polymers and filamentous Pf bacteriophages.
• Characterization of the liquid crystalline properties of the biofilm matrix.
• Detection of Pf bacteriophages in clinical isolates and cystic fibrosis sputum samples.
• Experimental assembly of liquid crystals using sputum polymers, serum, and Pf bacteriophage.

Main Results:

• The extracellular matrix of Pseudomonas aeruginosa self-assembles into a liquid crystal via entropic interactions between polymers and filamentous Pf bacteriophages.
• This liquid crystalline organization enhances biofilm adhesion, desiccation tolerance, and antibiotic resistance.
• Pf bacteriophages are common in P. aeruginosa clinical isolates and were found in cystic fibrosis sputum.
• Pf bacteriophage addition induced rapid liquid crystal formation in sputum polymers and serum.
• A related bacteriophage, Fd from Escherichia coli, demonstrated similar biofilm-building capabilities.

Conclusions:

• Filamentous bacteriophages play a crucial role in the liquid crystalline self-assembly of bacterial biofilms.
• The liquid crystalline nature of the biofilm matrix is key to its enhanced functional properties.
• Targeting filamentous bacteriophages or the liquid crystalline matrix organization presents a promising avenue for novel antibacterial strategies.