TABLE 1.

Bacterial strains and plasmid used in this study

Strain or plasmid	Relevant genotype or phenotypea	Source or reference
P. aeruginosa
CHA	Mucoid CF isolate	31
CHA-D1	exsA::Gmr mutant of CHA	3
REN0	CF isolate	This work
REN0-D1	exsA::Gmr mutant of REN0	This work
CF1	CF isolate	This work
CF1-D1	exsA::Gmr mutant of CF1	This work
Plasmid pDD2	pUCP20-derived plasmid containing exsA	3

^aGm^r, gentamicin resistance.