A. Miller assays were used to measure expression of the exoS-lacZ fusion in wild type and mutant strains of P. aeruginosa. As induction of the T3S genes occurs under conditions of low calcium, cultures were grown in Ca2+-depleted (grey bars) and Ca2+-replete (white bars) LB media, at 37°C for 4 hours.
B. Biofilm phenotypes were measured in wild type and mutant strains of P. aeruginosa as the attachment of bacteria to tubes and formation of biofilm rings and pellicles after 14 and 20 h static incubation at 30°C.