[A novel screening system for Pseudomonas aeruginosa quorum sensing inhibitors].

Quorum sensing is an important gene regulatory mechanism in Pseudomonas aeruginosa and controls the expression of numerous virulence factors. We designed and constructed a screening system for quorum-sensing inhibitors. We developed the system by using the lasI and rhlA promoters fused with promoterless sacB as reporters. Using this system we screened a number of Chinese herb extracts, and identified three herb extracts containing inhibitors to the quorum-sensing system and to its regulated genes. The screening system developed was highly efficient and sensitive. It could serve as a useful tool to identify herb compounds that block infections but unlikely render antibiotic resistance in pathogens.