Bacterial Infections and Mycoses Commons^™

The Impact Of Exos On Pseudomonas Aeruginosa Internalization By Epithelial Cells Is Independent Of Fleq And Correlates With Bistability Of Type Three Secretion System Gene Expression, Abby R. Kroken, Camille K. Chen, David J. Evans, Timothy L. Yahr, Suzanne M. J. Fleiszig

Faculty Publications & Research of the TUC College of Pharmacy

Pseudomonas aeruginosa is internalized into multiple types of epithelial cell in vitro and in vivo and yet is often regarded as an exclusively extracellular pathogen. Paradoxically, ExoS, a type three secretion system (T3SS) effector, has antiphagocytic activities but is required for intracellular survival of P. aeruginosaand its occupation of bleb niches in epithelial cells. Here, we addressed mechanisms for this dichotomy using invasive (ExoS-expressing) P. aeruginosaand corresponding effector-null isogenic T3SS mutants, effector-null mutants of cytotoxic P. aeruginosa with and without ExoS transformation, antibiotic exclusion assays, and imaging using a T3SS-GFP reporter. Except for effector-null PA103, all strains were internalized while …