Pyoverdine Assay for Rapid and Early Detection of Pseudomonas aeruginosa in Burn Wounds

Infection is responsible for up to 60% of deaths in burn patients, and Pseudomonas aeruginosa (PA) has the highest mortality rate among all causes of bacteremia. These aggressive and virulent infections are often not detected until there is a positive blood culture for PA, meaning the patient already has bacteremia. An assay that rapidly detects PA while it is still present at low numbers within the burn wound could therefore be transformative, as it would allow for early and more effective treatment intervention. Pyoverdine, an Fe³⁺ chelating fluorescent molecule, is produced by PA to overcome the problem of limited iron availability and is essential for PA to cause acute infections. Here, we report the development and use of a simple qualitative pyoverdine assay for detection of PA in a clinically relevant in vivo burn wound model. In contrast with the 24 h quantitative culture approaches currently used, the pyoverdine assay is complete within 15 min. The assay has a PA detection limit of ∼10⁶ colony forming units/(g of tissue) and detects the PA-specific biomarker pyoverdine within burn wounds before the pathogen disseminates within the body, evidence that the assay can detect lower, prebacteremic levels of PA within burn wounds.