title: Evaluation of the new VITEK 2 extended-spectrum beta-lactamase (ESBL) test for rapid detection of ESBL production in Enterobacteriaceae isolates.
abstract: Extended-spectrum beta-lactamases (ESBLs) are a large, rapidly evolving group of enzymes that confer resistance to oxyimino cephalosporins and monobactams and are inhibited by clavulanate. Rapid reliable detection of ESBL production is a prerequisite for successful infection management and for monitoring resistance trends and implementation of intervention strategies. We evaluated the performance of the new VITEK 2 ESBL test system (bioMérieux, Inc, Hazelwood, Mo.) in the identification of ESBL-producing Enterobacteriaceae isolates. We examined a total of 1,129 clinically relevant Enterobacteriaceae isolates (including 218 that had been previously characterized). The ESBL classification furnished by the VITEK 2 ESBL test system was concordant with that of the comparison method (molecular identification of beta-lactamase genes) for 1,121 (99.3%) of the 1,129 isolates evaluated. ESBL production was correctly detected in 306 of the 312 ESBL-producing organisms (sensitivity, 98.1%; positive predictive value, 99.3%). False-positive results emerged for 2 of the 817 ESBL-negative isolates (specificity, 99.7%; negative predictive value, 99.3%). VITEK 2 ESBL testing took 6 to 13 h (median, 7.5 h; mean +/- SD, 8.2 +/- 2.39 h). This automated short-incubation system appears to be a rapid and reliable tool for routine identification of ESBL-producing isolates of Enterobacteriaceae.
authors.affiliation: Institute of Microbiology, Caholic University of the Sacred Heart, Rome, Italy. tspanu@rm.unicatt.it
authors.forename: Teresa
authors.initials: T
authors.lastname: Spanu
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
authors.forename: Mario
authors.initials: M
authors.lastname: Tumbarello
authors.forename: Tiziana
authors.initials: T
authors.lastname: D'Inzeo
authors.forename: Barbara
authors.initials: B
authors.lastname: Fiori
authors.forename: Brunella
authors.initials: B
authors.lastname: Posteraro
authors.forename: Rosaria
authors.initials: R
authors.lastname: Santangelo
authors.forename: Roberto
authors.initials: R
authors.lastname: Cauda
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fadda
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000145:classification* / Q000187:drug effects* / Q000201:enzymology; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D005189:False Positive Reactions; D006801:Humans; D008826:Microbial Sensitivity Tests; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013997:Time Factors; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D011933:Reagent Kits, Diagnostic; D001618:beta-Lactamases