title: Suppression of virulence factors of Pseudomonas aeruginosa by erythromycin.
abstract: The effects of erythromycin stearate over a concentration range of 0.1-10 mg/l on production of elastase, protease and leucocidin by clinical isolates of Pseudomonas aeruginosa were investigated. Growth of P. aeruginosa N42 in broth was not affected significantly during 24 h culture with erythromycin (0.1-10 mg/l), although extracellular protein contents were reduced by erythromycin at concentrations of 0.1-1.0 mg/l. Production of elastase and protease by strain N42 was significantly suppressed by erythromycin with a maximum inhibition at 0.5 mg/l, but the complete inhibition of enzyme production was not achieved. In contrast, leucocidin production by strain N42 was completely impaired by erythromycin at concentrations of 0.1-5.0 mg/l. Although the leucotoxic activity, as determined by vital staining, was not detected, the leucocidin fraction prepared from the autolysate of strain N42 cultured with 10 mg/l of erythromycin induced morphological changes in human leucocytes, resulting in release of elastase. Erythromycin exerted similar effects on other clinical isolates of P. aeruginosa. These findings indicate that erythromycin might have a role in P. aeruginosa infection, although it has no direct antibacterial activity.
authors.affiliation: Department of Bacteriology, Nara Medical University, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Kita
authors.forename: M
authors.initials: M
authors.lastname: Sawaki
authors.forename: D
authors.initials: D
authors.lastname: Oku
authors.forename: A
authors.initials: A
authors.lastname: Hamuro
authors.forename: K
authors.initials: K
authors.lastname: Mikasa
authors.forename: M
authors.initials: M
authors.lastname: Konishi
authors.forename: M
authors.initials: M
authors.lastname: Emoto
authors.forename: S
authors.initials: S
authors.lastname: Takeuchi
authors.forename: N
authors.initials: N
authors.lastname: Narita
authors.forename: S
authors.initials: S
authors.lastname: Kashiba
mesh_terms: D001426:Bacterial Proteins; D004790:Enzyme Induction / Q000187:drug effects; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000494:pharmacology; D007956:Leukocidins / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification; D008666:Metalloendopeptidases / Q000096:biosynthesis*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology / Q000472:pathogenicity*; D012697:Serine Endopeptidases / Q000096:biosynthesis*; D014774:Virulence / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D007956:Leukocidins; D004917:Erythromycin; C038495:Pseudomonas serine proteinase; D012697:Serine Endopeptidases; D008666:Metalloendopeptidases; C043859:pseudolysin, Pseudomonas aeruginosa; C011462:erythromycin stearate