Production of Pseudomonas aeruginosa Intercellular Small Signaling Molecules in Human Burn Wounds

Area of Science:

• Microbiology
• Bacterial Pathogenesis
• Molecular Biology

Background:

• Pseudomonas aeruginosa utilizes quorum sensing via signaling molecules to regulate virulence.
• The transcriptional regulator MvfR controls key virulence factors through ligands 4-hydroxy-2-alkylquinolines (HAQs), specifically 4-hydroxy-2-heptylquinoline (HHQ) and 3,4-dihydroxy-2-heptylquinoline (PQS).
• Observed differences in HHQ and PQS ratios between bacterial cultures and infected animal models suggest context-dependent production.

Observation:

• Investigated the presence and ratios of HHQ and PQS during human P. aeruginosa acute wound infections.
• Examined if these ratios mirror those found in P. aeruginosa-infected mice.
• Assessed if HAQs are detectable in human wound tissue and drainage.

Findings:

• Clinically relevant P. aeruginosa isolates produced detectable HAQs in human wound infections.
• The ratios of HHQ and PQS in human wounds were similar to those in infected animal models, not bacterial cultures.
• HAQs were successfully isolated and quantified from both human wound tissue and drainage fluid.

Implications:

• Demonstrates for the first time the isolation and quantification of HAQs from human acute wound infection sites.
• Validates the use of mammalian infection models for studying P. aeruginosa quorum sensing and virulence.
• Provides crucial insights into the in vivo role of HAQs in P. aeruginosa pathogenesis during human infections.