Evaluation of a commercial automated system for the identification of gram-negative enteric bacilli

A total of 908 distinct clinical isolates and 60 reference strains of aerobic gram-negative bacilli were identified by our own in-house biochemical identification system (RHH) and by a commercial automated system (Mastascan Colour). Overall, both systems performed well in the identification of routine isolates of aerobic gram-negative bacilli, with only six discrepancies between the two systems. These six organisms were species infrequently encountered in the clinical microbiology laboratory. Of the 60 reference strains, many of which were biochemically atypical, the RHH system was unable to identify one and mis-identified two others. The commercial system was unable to identify one strain and misidentified five others. Both systems were inexpensive in terms of consumable materials, and the commercial system was compatible with the routine work of the department.