title: Postantibiotic effect of antimicrobial combinations on multidrug-resistant Pseudomonas aeruginosa.
abstract: The application of antimicrobial combinations on multidrug-resistant Pseudomonas aeruginosa might be of clinical relevance if they possess a significant postantibiotic effect (PAE). Twenty-two nosocomial isolates were exposed over time to ceftazidime, imipenem, or ciprofloxacin, and to their interaction with amikacin; all were applied at concentrations equal to their average serum level. After 24 h of exposure, live cells were washed and resuspended into fresh broth, and bacterial growth was monitored. PAE was found only for isolates subjected to the synergistic effect of the applied interactions. For these isolates, the mean PAEs (+/-SE) were 3.10 +/- 0.71 h for ceftazidime and amikacin, 4.38 +/- 0.83 h for imipenem and amikacin, and 3.33 +/- 2.83 h for ciprofloxacin and amikacin. The prolonged PAE documented after exposure to the interactions of the studied drugs strengthens the application of their combination for the management of infections by multidrug-resistant P. aeruginosa.
authors.affiliation: 4th Department of Internal Medicine, Attikon University General Hospital, University of Athens, Medical School, 124 64 Athens, Greece. giamarel@internet.gr
authors.forename: Evangelos J
authors.initials: EJ
authors.lastname: Giamarellos-Bourboulis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kentepozidis
authors.forename: Anastasia
authors.initials: A
authors.lastname: Antonopoulou
authors.forename: Diamantis
authors.initials: D
authors.lastname: Plachouras
authors.forename: Thomas
authors.initials: T
authors.lastname: Tsaganos
authors.forename: Helen
authors.initials: H
authors.lastname: Giamarellou
mesh_terms: D000583:Amikacin / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D004357:Drug Synergism; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
chemical_list: D015378:Imipenem; D000583:Amikacin; D002442:Ceftazidime