title: Comparison of the autoSCAN-W/A rapid bacterial identification system and the Vitek AutoMicrobic system for identification of gram-negative bacilli.
abstract: The autoSCAN-W/A (W/A; Baxter MicroScan, West Sacramento, Calif.) with the new fluorometric Rapid Neg Combo 1 (RNC) panel is a fully automated fluorometric system for identification of both enteric and nonenteric gram-negative bacilli within 2 h. We compared the W/A with the Vitek AutoMicrobic System (Vitek AMS; Vitek Systems, Inc., Hazelwood, Mo.) for identification of 383 clinical isolates of gram-negative bacilli. The API 20E (Analytab Products, Plainview, N.Y.) and conventional biochemical testing were used as the reference systems. The W/A correctly identified 336 isolates (87.7%) to the species level and classified an additional 29 isolates (7.6%) as correct with low probability (overall identification = 95.3%); the Vitek AMS correctly identified 355 isolates (92.7%) to the species level and classified an additional 8 isolates (2.1%) as correct with low probability (overall identification = 94.8%). A common set of 134 isolates of gram-negative bacilli was tested in both participating laboratories as a means of assessing interlaboratory agreement with both the W/A and the Vitek AMS. The overall agreements between the two laboratories were 86% with the W/A and 92% with the Vitek AMS. The W/A performed comparably to the Vitek AMS for identification of most gram-negative bacilli, actually exceeding the Vitek AMS for identification of nonenteric bacilli. Rapid time to identification and a high level of automation make the W/A an attractive system for clinical microbiology laboratories.
authors.affiliation: Iowa City Veteran's Affairs Medical Center, Iowa.
authors.forename: M A
authors.initials: MA
authors.lastname: Pfaller
authors.forename: D
authors.initials: D
authors.lastname: Sahm
authors.forename: C
authors.initials: C
authors.lastname: O'Hara
authors.forename: C
authors.initials: C
authors.lastname: Ciaglia
authors.forename: M
authors.initials: M
authors.lastname: Yu
authors.forename: N
authors.initials: N
authors.lastname: Yamane
authors.forename: G
authors.initials: G
authors.lastname: Scharnweber
authors.forename: D
authors.initials: D
authors.lastname: Rhoden
mesh_terms: D001431:Bacteriological Techniques; D004755:Enterobacteriaceae / Q000145:classification / Q000302:isolation & purification; D005069:Evaluation Studies as Topic; D005470:Fluorometry; D006090:Gram-Negative Bacteria / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D012680:Sensitivity and Specificity