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

Abstract

Pseudomonas aeruginosa produces multiple toxins and exoenzymes that contribute to its survival and ability to cause disease. As prior studies reported an important role for type III-secretion in the severity of corneal disease in P. aeruginosa keratitis, we examined if there is a requirement for the type II-secreted cytotoxin Exotoxin A (ToxA) in bacterial persistence and disease severity in infected murine corneas. Using independently generated {Delta}toxA mutants and complemented strains, we found that ToxA is expressed in vivo, but ToxA deletion did not significantly affect bacterial replication, neutrophil recruitment or disease severity. These findings contrast with an earlier study identifying a critical role for ToxA.