Relationship between Pyochelin and Pseudomonas Quinolone Signal in Pseudomonas aeruginosa : A Direction for Future Research

is an opportunistic pathogen that requires iron to survive in the host; however, the host immune system limits the availability of iron. Pyochelin (PCH) is a major siderophore produced by during infection, which can help survive in an iron-restricted environment and cause infection. The infection activity of is regulated by the quinolone signal (PQS) quorum-sensing system. The system uses 2-heptyl-3-hydroxy-4-quinolone (PQS) or its precursor, 2-heptyl-4-quinolone (HHQ), as the signal molecule. PQS can control specific life processes such as mediating quorum sensing, cytotoxicity, and iron acquisition. This review summarizes the biosynthesis of PCH and PQS, the shared transport system of PCH and PQS, and the regulatory relationship between PCH and PQS. The correlation between the PQS and PCH is emphasized to provide a new direction for future research.