Metabolite transfer with the fermentation product 2,3-butanediol enhances virulence by Pseudomonas aeruginosa

Area of Science:

• Microbiology
• Infectious Diseases
• Cystic Fibrosis Research

Background:

• Cystic fibrosis (CF) airways host persistent microbial communities, with Pseudomonas aeruginosa as a key pathogen.
• Interactions between microbes in polymicrobial CF infections are crucial but poorly understood.
• Understanding these interactions is vital for developing effective CF treatments.

Purpose of the Study:

• To investigate how fermentation products from co-habitant bacteria influence P. aeruginosa virulence.
• To elucidate the metabolic relationship between fermenting bacteria and P. aeruginosa in CF airways.
• To determine the impact of interbacterial metabolite transfer on P. aeruginosa pathogenesis.

Main Methods:

• In vitro experiments exposing P. aeruginosa to common bacterial fermentation products.
• Quantification of virulence factor production, antimicrobial activity, and biofilm formation.
• Analysis of gene expression, specifically the LasI/LasR quorum-sensing system.

Main Results:

• Fermentation products, particularly 2,3-butanediol, significantly increased P. aeruginosa virulence factors, antimicrobial activity, and biofilm formation compared to glucose.
• 2,3-butanediol acts as a substrate for P. aeruginosa, establishing a metabolic link.
• Upregulation of the LasI/LasR quorum-sensing system by 2,3-butanediol led to increased phenazine and exotoxin concentrations and enhanced biofilm.

Conclusions:

• The success of P. aeruginosa in CF airways is influenced by its position in the microbial food web and interactions with fermenting bacteria.
• Interbacterial metabolite transfer significantly stimulates P. aeruginosa virulence.
• These findings suggest that targeting metabolic interactions could impact CF disease progression.