From saprophyte to pathogen: Multidrug-resistant Pseudomonas fluorescens wound infection in two patients

Pseudomonas fluorescens, an environmental rhizobacterium, is a rare cause of human wound infection. We describe two patients: a 73-year-old man with a 6-month diabetic foot ulcer, and a 30-year-old woman with a 2-month foot ulcer, whose wound swabs yielded multidrug-resistant P. fluorescens in pure culture. Identification relied on standard phenotypic methods, including pyoverdine fluorescence on King's B medium; molecular confirmation was not performed. Both isolates were meropenem-susceptible. Both patients received targeted intravenous meropenem with debridement and wound care, improving clinically, with culture-confirmed clearance in one. Susceptibility-guided therapy is essential given this organism's intrinsic resistance.