Pseudomonas aeruginosa exotoxin A is not essential for corneal disease severity or bacterial survival.

Pseudomonas aeruginosa produces multiple toxins and exoenzymes that contribute to its survival and ability to cause disease. In the current study, we examined whether the type II-secreted cytotoxin Exotoxin A (ToxA) is required for P. aeruginosa growth and disease severity in infected murine corneas. Using ΔtoxA mutants and complemented strains on a PAO1 background, we report that although ToxA is produced during corneal infection, ToxA deletion did not significantly affect bacterial replication, neutrophil recruitment, or disease severity in infected corneas. These findings contrast with an earlier study identifying a role for ToxA in P. aeruginosa keratitis.