title: Stable antimicrobial susceptibility rates for clinical isolates of Pseudomonas aeruginosa from the 2001-2003 tracking resistance in the United States today surveillance studies.
abstract: From 2001 to 2003, rates of susceptibility to piperacillin-tazobactam (86%), ceftazidime (80%), ciprofloxacin (68%), and levofloxacin (67%) did not decrease or decreased by <1.5%, whereas the rate of susceptibility to gentamicin decreased by 3.2% (from 75.5% to 72.3%) and the rate of susceptibility to imipenem decreased by 5.6% (from 84.4% to 78.8%), for 2394 clinical isolates of Pseudomonas aeruginosa collected in the Tracking Resistance in the United States Today surveillance studies. Rates of multidrug resistance (i.e., resistance to > or =3 antimicrobial agents) increased from 7.2% in 2001 to 9.9% in 2003 and were significantly higher for isolates from the East North Central and Mid-Atlantic regions of the United States than for isolates from other regions. Analysis of minimum inhibitory concentrations (MICs) suggested that combining an antipseudomonal beta -lactam with ciprofloxacin or levofloxacin would yield a 3.4%-7.1% increase in the percentage of isolates susceptible to the combination, compared with the beta -lactam alone. Ratios of the area under the serum concentration-time curve values for free drug to modal MICs for ciprofloxacin and levofloxacin were similar and were >125 (target ratio), whereas those ratios for gatifloxacin and moxifloxacin were significantly lower. Ongoing surveillance of P. aeruginosa is essential.
authors.affiliation: Focus Bio-Inova, Herndon, Virginia 20171-4603, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Karlowsky
authors.forename: Mark E
authors.initials: ME
authors.lastname: Jones
authors.forename: Clyde
authors.initials: C
authors.lastname: Thornsberry
authors.forename: Alan T
authors.initials: AT
authors.lastname: Evangelista
authors.forename: Y Cheung
authors.initials: YC
authors.lastname: Yee
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Sahm
mesh_terms: D002442:Ceftazidime / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D024841:Fluoroquinolones / Q000494:pharmacology; D000077734:Gatifloxacin; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D010878:Piperacillin / Q000494:pharmacology; D000077725:Piperacillin, Tazobactam Drug Combination; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D014481:United States; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D024841:Fluoroquinolones; D005839:Gentamicins; D047090:beta-Lactams; D000077725:Piperacillin, Tazobactam Drug Combination; D002939:Ciprofloxacin; D010397:Penicillanic Acid; D002442:Ceftazidime; D000077734:Gatifloxacin; D010878:Piperacillin