title: Impact of organism species on microbial eradication and development of resistance in severe gram-negative pneumonia.
abstract: This study evaluated the species differences in microbiological outcomes of Gram-negative bacteria (GNB) causing severe pneumonia from the viewpoint of area under the concentration-time curve/MIC ratio (AUC/MIC). In total, 111 strains of GNb from 74 patients were analyzed. Overall, microbiological eradication was achieved in 88% of the cases with initial AUC/MIC>119. However, relapse often occurred when resistance developed or AUC/miC was <176. Pseudomonas aeruginosa and Enterobacter spp. were commonly involved in failed microbiological eradication and development of resistance. The AUC/MIC required for initial eradication of P. aeruginosa was much higher (478) and antibiotic resistance in P. aeruginosa and Enterobacter spp. occurred less frequently with combination therapy (10.0% vs. 67.7%). These data argue that target magnitudes of AUC/MIC to eradicate GNB differ by species. Since antibiotic resistance developed in some species of GNB despite high AUC/MIC, strategies to minimize development of resistance, including combination therapy, must be considered.
authors.affiliation: School of Pharmacy, University of Buffalo, New York 14260, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kiem
authors.forename: J J
authors.initials: JJ
authors.lastname: Schentag
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D019540:Area Under Curve; D004311:Double-Blind Method; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D012008:Recurrence
chemical_list: D000900:Anti-Bacterial Agents