title: Roles of Pseudomonas aeruginosa autoinducers and their degradation products, tetramic acids, in bacterial survival and behavior in ecological niches.
abstract: Pseudomonas aeruginosa, an opportunistic pathogen, is known to mainly use N-acylhomoserine lactones (AHLs) as autoinducers. Recent progress in this field demonstrated that not only AHLs, but also their degradation products, tetramic acids, may have some biological activities. The present study examined the roles of Pseudomonas autoinducers and tetramic acids in bacterial survival and behavior in ecological niches. P. aeruginosa autoinducers and the tetramic acid derivatives were chemically synthesized, and the structure-activity correlation was investigated. Some tetramic acids derived from AHLs caused a significant reduction in the viability of P. aeruginosa in a concentration dependent manner (30-300 µM). The smaller the inoculum of bacteria, the stronger the bactericidal activity that was observed. The data from tetramic acid derivatives indicated the keto-enol structure of tetramic acid to be critical for the antibacterial activity. Exogenous tetramic acid did not induce significant changes in the formation of biofilm or production of exoproducts such as pyocyanin and elastase. Tetramic acid and disinfectants acted synergistically to kill P. aeruginosa. These results suggest the AHL-degradation product tetramic acid to be useful for bacterial control.
authors.affiliation: Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo 143–8530, Japan.
authors.forename: Natsue
authors.initials: N
authors.lastname: Hosono Honda
authors.forename: Soichiro
authors.initials: S
authors.lastname: Kimura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tateda
authors.forename: Manabu
authors.initials: M
authors.lastname: Horikawa
authors.forename: Chihiro
authors.initials: C
authors.lastname: Ueda
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ishii
authors.forename: Masaji
authors.initials: M
authors.lastname: Ishiguro
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyairi
authors.forename: Keizo
authors.initials: K
authors.lastname: Yamaguchi
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology; D004926:Escherichia coli / Q000254:growth & development; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000502:physiology; D007711:Klebsiella pneumoniae / Q000254:growth & development; D007783:Lactones / Q000378:metabolism; D050296:Microbial Viability / Q000187:drug effects; D015394:Molecular Structure; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000378:metabolism*; D011760:Pyrrolidinones / Q000494:pharmacology; D053038:Quorum Sensing / Q000502:physiology; D013329:Structure-Activity Relationship
chemical_list: D054742:Acyl-Butyrolactones; D000900:Anti-Bacterial Agents; D004202:Disinfectants; D007783:Lactones; D011760:Pyrrolidinones; C085113:Pseudomonas aeruginosa autoinducer; C009435:tetramic acid; D006714:Homoserine