title: Modification of Pseudomonas aeruginosa virulence factors by sub-inhibitory concentrations of antibiotics.
abstract: This study's objectives were to evaluate the effects of subminimum inhibitory concentrations (MICs) of tobramycin, gentamicin, netilmicin, streptomycin, ciprofloxacin, cefotaxime and piperacillin on proteinase production, alginate and siderophore synthesis by two strains of Pseudomonas aeruginosa. One of these strains, of recent clinical isolation, was mucoid. In fact it is well known that mucoid strains are more resistant than non-mucoid; there is, moreover, evidence that in cystic fibrotic lungs the non-mucoid P. aeruginosa are invariably replaced by mucoid variants. Our results show that subinhibitory concentrations of beta-lactams and quinolones significantly reduced the amount of alginate. Protease production was affected by all antibiotics tested.
authors.affiliation: II Cattedra di Microbiologia, Facoltà di Medicina e Chirurgia, Università degli Studi di Roma, La Sapienza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Trancassini
authors.forename: M I
authors.initials: MI
authors.lastname: Brenciaglia
authors.forename: M C
authors.initials: MC
authors.lastname: Ghezzi
authors.forename: P
authors.initials: P
authors.lastname: Cipriani
authors.forename: F
authors.initials: F
authors.lastname: Filadoro
mesh_terms: D000464:Alginates / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D010450:Endopeptidases / Q000096:biosynthesis*; D005839:Gentamicins / Q000494:pharmacology; D007502:Iron Chelating Agents / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D010878:Piperacillin / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity*; D017262:Siderophores; D014031:Tobramycin / Q000494:pharmacology; D014774:Virulence / Q000187:drug effects
chemical_list: D000464:Alginates; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D005839:Gentamicins; D007502:Iron Chelating Agents; D017262:Siderophores; D010450:Endopeptidases; D014031:Tobramycin; D010878:Piperacillin