The effects of subinhibitory concentrations (1/4, 1/8, 1/16 of the MIC) of quinolones (ciprofloxacin, enoxacin, nalidixic acid, norfloxacin, ofloxacin, pefloxacin), aminoglycosides (amikacin, gentamicin, netilmicin, streptomycin, tobramycin), beta-lactams (aztreonam, ceftazidime, imipenem, ticarcilin) and macrolides (erythromycin, roxitromycin) on the excretion of alginate by a P. aeruginosa strain were studied. Both beta-lactam and macrolide antibiotics were found ineffective at the concentrations tested, except erythromycin and imipenem at 1/4 MIC. Aminoglycosides at a concentration of 1/4 MIC reduced most effectively the excretion of alginate. Quinolones were also effective at this sub-MIC; 1/16 MIC was ineffective with all antibiotics or stimulated the production of alginate.

• MeSH
• Alginates metabolism   MeSH
• Aminoglycosides MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Quinolones pharmacology   MeSH
• Lactams MeSH
• Macrolides MeSH
• Microbial Sensitivity Tests MeSH
• Pseudomonas aeruginosa drug effects   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alginates MeSH
• Aminoglycosides MeSH
• Anti-Bacterial Agents MeSH
• Quinolones MeSH
• Lactams MeSH
• Macrolides MeSH

The postantibiotic effect (PAE) (postantibiotic phase induced by 2x or 4x MIC) as well as the postantibiotic effect of subinhibitory concentrations (0.1x, 0.2x and 0.3x MIC) (PA SME) of netilmicin, tobramycin, ciprofloxacin and pefloxacin affected the production of the virulence factor alginate by a P. aeruginosa strain. Aminoglycosides and ciprofloxacin at a concentration of 4x MIC inhibited the alginate production more significantly than 2x MIC. Suprainhibitory concentrations of aminoglycosides were more effective than pefloxacin (2x or 4x MIC) and ciprofloxacin (2x MIC). PA SME demonstrated by the above antibiotics (with the exception of ciprofloxacin 2x MIC + 0.1x MIC) suppressed alginate production more efficiently.

• MeSH
• Alginates metabolism   MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Anti-Infective Agents pharmacology   MeSH
• Depression, Chemical MeSH
• Ciprofloxacin administration & dosage   pharmacology   MeSH
• Gentamicins administration & dosage   pharmacology   MeSH
• Cross Infection microbiology   MeSH
• Glucuronic Acid MeSH
• Hexuronic Acids MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Netilmicin administration & dosage   pharmacology   MeSH
• Pefloxacin administration & dosage   pharmacology   MeSH
• Pseudomonas Infections microbiology   MeSH
• Pseudomonas aeruginosa drug effects   isolation & purification   metabolism   pathogenicity   MeSH
• Tobramycin administration & dosage   pharmacology   MeSH
• Virulence drug effects   MeSH
• Dose-Response Relationship, Drug MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• Alginates MeSH
• Anti-Bacterial Agents MeSH
• Anti-Infective Agents MeSH
• Ciprofloxacin MeSH
• Gentamicins MeSH
• Glucuronic Acid MeSH
• Hexuronic Acids MeSH
• Netilmicin MeSH
• Pefloxacin MeSH
• Tobramycin MeSH