title: Performance of Vitek 2 in antimicrobial susceptibility testing of Pseudomonas aeruginosa isolates with different mechanisms of beta-lactam resistance.
abstract: A total of 78 isolates of Pseudomonas aeruginosa grouped according to the phenotype for ceftazidime and imipenem susceptibility/resistance were used to assess the accuracy of the Vitek 2 system in antimicrobial susceptibility testing. Comparisons were made with a MIC gradient test for piperacillin-tazobactam, ceftazidime, aztreonam, imipenem, meropenem, gentamicin, and ciprofloxacin. For the total of 546 isolate-antimicrobial combinations tested, the category agreement was 83.6%, with 2.0, 1.6, and 12.8% very major, major, and minor errors, respectively. Vitek 2 accuracy was influenced differently by the mechanism responsible for resistance, and interpretation of the results in relation to phenotype could improve the performance of the system.
authors.affiliation: Dipartimento di Patologia, Sezione di Microbiologia, Università di Verona, Verona, Italy.
authors.forename: Annarita
authors.initials: A
authors.lastname: Mazzariol
authors.forename: Marco
authors.initials: M
authors.lastname: Aldegheri
authors.forename: Marco
authors.initials: M
authors.lastname: Ligozzi
authors.forename: Giuliana
authors.initials: G
authors.lastname: Lo Cascio
authors.forename: Raffaella
authors.initials: R
authors.lastname: Koncan
authors.forename: Roberta
authors.initials: R
authors.lastname: Fontana
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002442:Ceftazidime / Q000494:pharmacology; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010641:Phenotype; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D018440:beta-Lactam Resistance; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D011933:Reagent Kits, Diagnostic; D047090:beta-Lactams; D015378:Imipenem; D002442:Ceftazidime