Antipseudomonal Agents Exhibit Differential Pharmacodynamic Interactions with Human Polymorphonuclear Leukocytes against Established Biofilms of Pseudomonas aeruginosa

摘要: Pseudomonas aeruginosa is the most common pathogen infecting lower respiratory tract of cystic fibrosis (CF) patients, where it forms tracheobronchial biofilms. biofilms are refractory to antibacterials and phagocytic cells with innate immunity, leading infection. Little known about interaction between antipseudomonal agents in eradication P. Herein, we investigated capacity three agents, amikacin (AMK), ceftazidime (CAZ), ciprofloxacin (CIP), interact human polymorphonuclear leukocytes (PMNs) against planktonic isolates recovered from sputa CF patients. Three were resistant susceptible each these antibiotics. The concentrations studied (2, 8, 32 mg/liter) subinhibitory for isolates, whereas they ranged sub-MIC 2 × MIC values. activity antibiotic alone or combination PMNs 48-h mature was determined by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assay. All combinations AMK resulted synergistic additive effects compared component alone. More than 75% CAZ exhibited interactions CIP had mostly antagonistic no aeruginosa. Our findings demonstrate a greater positive that observed especially