Detection of Pseudomonas aeruginosa in Whole Blood using a portable Magnetic Particle Spectrometer - a feasibility study

Rapid identification of WHO critical priority pathogens, such as Pseudomonas aeruginosa, is essential for managing sepsis, where standard blood cultures cause diagnostic delays of 24-72 hours. To address this, we developed a rapid, culture-independent magnetic immunoassay using a portable Magnetic Particle Spectroscopy (MPS) device for the direct detection of P. aeruginosa in blood. We evaluated two SPION formulations and found that our developed formulation, SPION-152, demonstrated excellent specificity, generating a strong signal change with virulent P. aeruginosa strains while showing negligible cross-reactivity with E. coli. Specificity for a virulence-associated factor was confirmed using a knockout mutant. These findings validate the MPS platform as a promising tool for accelerating pathogen identification in patients with suspected sepsis.