EFFECT OF TREATMENT WITH 4,5-DIHYDROXY- 2-CYCLOPENTEN-1-ONE (DHCP) ON GENE EXPRESSION AND QUORUM-SENSING IN BACTERIA

摘要

DHCP (4,5-dihydroxy-2-cyclopenten-1-one) has been previously shown to have antibacterial activity against Escherichia coli. Global transcriptional pattern of E. coli was analyzed in response to DHCP by DNA microarray. It is now shown that DHCP has widespread effects in E. coli, affecting genes encoding proteins involved in general metabolism and cell membrane synthesis and functions. In addition, rpoS and RpoS-regulated genes responding to various stresses are upregulated. DHCP is also shown to inhibit AI-2, an autoinducer involved in interspecies quorum-sensing, and the genes comprising quorum-regulated processes such as virulence, motility and outer membrane functions are downregulated by DHCP treatment. In addition, cysK which is a known quorum-sensing gene working in an alternate pathway(s) in E. coli increases considerably in response to DHCP. These results suggest that DHCP regulates the switching on/off of the different quorum-sensing circuits in E. coli.