title: Role for rpoS gene of Pseudomonas aeruginosa in antibiotic tolerance.
abstract: The alternative sigma factor, RpoS has been described as a central regulator of many stationary phase-inducible genes and a master stress-response regulator under various stress conditions. We constructed an rpoS mutant in Pseudomonas aeruginosa and investigated the role of rpoS gene in antibiotic tolerance. The survival of the rpoS mutant cells in stationary phase was approximately 70 times lower when compared with that of the parental strain at 37 degrees C for 2 h after the addition of biapenem. For imipenem, the survival was approximately 40 times lower. Heat stress promoted an increase in the survival of the parental strain to biapenem, but the same was not found to be the case for the rpoS mutant. Our results indicate that rpoS gene is involved in tolerance to antibiotics in P. aeruginosa during the stationary phase and heat stress. However, under osmotic stress, tolerance to biapenem was not dependent on the rpoS gene.
authors.affiliation: Department of Microbiology, Institute of Health Bioscience, Tokushima University Graduate School, Tokushima 770-8504, Japan. mkeiji@dent.tokushima-u.ac.jp
authors.forename: Keiji
authors.initials: K
authors.lastname: Murakami
authors.forename: Tsuneko
authors.initials: T
authors.lastname: Ono
authors.forename: Darija
authors.initials: D
authors.lastname: Viducic
authors.forename: Shizuo
authors.initials: S
authors.lastname: Kayama
authors.forename: Makiko
authors.initials: M
authors.lastname: Mori
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Hirota
authors.forename: Ken
authors.initials: K
authors.lastname: Nemoto
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Miyake
mesh_terms: D000222:Adaptation, Physiological; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology*; D015169:Colony Count, Microbial; D004361:Drug Tolerance / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006358:Hot Temperature; D015378:Imipenem / Q000494:pharmacology; D009154:Mutation; D009997:Osmotic Pressure; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D012808:Sigma Factor / Q000235:genetics* / Q000502:physiology*; D015398:Signal Transduction; D013845:Thienamycins / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D012808:Sigma Factor; D013845:Thienamycins; C069567:sigma factor KatF protein, Bacteria; D015378:Imipenem; C065257:biapenem