Comparison of MicroScan WalkAway system and Vitek system for identification of gram-negative bacteria

In a prospective side-by-side comparison conducted from September through November 1994, we compared the MicroScan WalkAway system, a conventional biochemical identification system (Dade MicroScan, Inc., Sacramento, Calif.), with the Vitek system (bioMerieux Vitek, Hazelwood, Mo. [analysis software version AMS-RO8.2] for the identification of gram-negative bacteria. Three-hundred thirty-one nonurine isolates and 493 urine isolates were tested. For nonurinary isolates, there was 91.5% agreement between the two methods. For urinary isolates, there was 97.4% agreement between the two methods. Overall, there was 95% agreement between the two systems. The results suggest that the current version of the MicroScan WalkAway system with conventional panels is essentially comparable to the current Vitek system.