A pilot study on the effect of the exoU gene on biofilm formation by a strain of Pseudomonas aeruginosa isolated from microbial keratitis

• An exoU knockout mutant of Pseudomonas aeruginosa PA169 was successfully generated from a microbial keratitis isolate. • Loss of exoU resulted in significantly reduced cytotoxicity toward human corneal epithelial cells. • Deletion of exoU significantly reduced biofilm formation, and confocal microscopy confirmed a marked reduction in biofilm thickness compared to the wild-type strain. • Findings demonstrated a contributory role of exoU in biofilm formation and virulence in keratitis-associated P. aeruginosa PA169.