title: Activity of cefepime, cefotaxime, ceftazidime, and aztreonam against extended-spectrum-producing isolates of Klebsiella pneumoniae and Escherichia coli from Chilean hospitals.
abstract: Resistance of Gram-negative bacilli to third-generation cephalosporins has been increasing due to the production of extended-spectrum beta-lactamases. In this work, the activities of cefepime, cefotaxime, ceftazidime, and aztreonam, alone and in association with clavulanic acid, against isolates of Klebsiella pneumoniae and Escherichia coli are compared. These isolates produce extended-spectrum beta-lactamases as shown by the synergy tests and by the decrease in the MICs of cephalosporins in the presence of clavulanic acid. Cefepime was the most active compound against these microorganisms. In addition, the microorganisms exhibited lower frequencies of resistance to this cephalosporin.
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile. rzemelman@mater.uss.cl
authors.forename: C
authors.initials: C
authors.lastname: Zemelman
authors.forename: H
authors.initials: H
authors.lastname: Bello
authors.forename: M
authors.initials: M
authors.lastname: Domínguez
authors.forename: G
authors.initials: G
authors.lastname: González
authors.forename: S
authors.initials: S
authors.lastname: Mella
authors.forename: R
authors.initials: R
authors.lastname: Zemelman
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001398:Aztreonam / Q000494:pharmacology; D000077723:Cefepime; D002439:Cefotaxime / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D002677:Chile; D019818:Clavulanic Acid / Q000494:pharmacology; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D019818:Clavulanic Acid; D000077723:Cefepime; D002442:Ceftazidime; D001618:beta-Lactamases; D001398:Aztreonam; D002439:Cefotaxime