Periodically disturbing biofilms reduces expression of quorum sensing-regulated virulence factors in Pseudomonas aeruginosa .

uses quorum sensing to regulate the expression of virulence factors. In static environments, spatial structures, such as biofilms, can increase the expression of these virulence factors. However, in natural settings, biofilms are exposed to physical forces that disrupt spatial structure, which may affect the expression of virulence factors regulated by quorum sensing. We show that periodically disturbing biofilms composed of using a physical force reduces the expression of quorum sensing-regulated virulence factors. At an intermediate disturbance frequency, the expression of virulence factors in the , , and regulons is reduced. Mathematical modeling suggests that perturbation of the receptor is critical for this reduction. Removing the receptor enhances the reduction in the expression of virulence factors as a result of disturbance. Our results allow identification of environments where virulence is reduced and implicate the receptor as having a buffering role against disturbance.