TABLE 1.

P. aeruginosa strains and mutants used in this study

Strain	Relevant characteristics	Reference(s)
Wild-type PA103	Functional ExsA-regulated TTSS; expresses two known effectors, ExoU and ExoT	13
Mutant PA103retS::Tn5	Tn5 insertion in retS, loss of ExsA-regulated TTSS and other epithelium-associated virulence mechanisms, upregulation of other virulence mechanisms, e.g., biofilm formation and exopolysaccharide expression	20, 27, 42
Mutant PA103exsA::Ω	Ω insertion in exsA, loss of ExsA-regulated TTSS and unknown ExsA-dependent virulence mechanisms	16
Mutant PA103exoU Tn5::Tcr	Tn5 insertion in exoU, loss of ExoU, expression of functional ExsA-regulated TTSS and effector ExoT	12
Mutant PA103exoT::Tcr	Tn insertion in exoT, loss of ExoT, expression of functional ExsA-regulated TTSS and effector ExoU	12
Mutant PA103exoU exoT::Tcr	Expression of functional ExsA-regulated TTSS, no expression of ExoU or ExoT	38