title: Evaluation of Vitek and API 20S for species identification of enterococci.
abstract: The performance of the Vitek System and the API 20S for identifying enterococci to the species level was evaluated in comparison with a conventional reference test scheme. A total of 369 isolates originally derived from a sample from 97 medical centers were tested, and the percentage of correctly identified organisms was (Vitek/API): 97.6%/79.2%, 95.3%/91.2%, and 86.0%/20.7% for Enterococcus faecalis, Enterococcus faecium, and Enterococcus non-faecalis-non-faecium species, respectively. In addition, the predictive values for species identification of the results reported by the systems were 98.1% for Vitek and 85.9% for API. The Vitek System GPI card (software version > or = 8.1) was considered to be very acceptable for enterococci identification, with errors principally among the rare Enterococcus raffinosus isolates.
authors.affiliation: Department of Pathology, University of Iowa College of Medicine, Iowa City, USA.
authors.forename: H S
authors.initials: HS
authors.lastname: Sader
authors.forename: D
authors.initials: D
authors.lastname: Biedenbach
authors.forename: R N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D001431:Bacteriological Techniques / Q000191:economics / Q000295:instrumentation*; D003365:Costs and Cost Analysis; D016983:Enterococcus / Q000145:classification / Q000302:isolation & purification*; D005069:Evaluation Studies as Topic; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity