FIG 1 .

Overview of the contribution of the two-component hybrid SagS to the motile-sessile and susceptible-resistance switches by P. aeruginosa cells. Upon P. aeruginosa transition to surface-associated growth, SagS directly interacts with and phosphorylates the TCS BfiSR, thus enabling surface-associated cells to transition to the irreversible attachment stage (31, 36). Moreover, transition to the irreversible attachment stage, regulated by SagS, marks the timing when surface-associated cells gain their heightened resistance to antimicrobial agents, with inactivation of sagS having been previously demonstrated to correlate with biofilm cells but not planktonic cells being more susceptible to antimicrobial agents (30, 36). SagS contributes to the activation of biofilm tolerance via c-di-GMP and the transcriptional regulator BrlR.