Evaluation of CrystalTM Rapid Stool/Enteric ID System for Identification of Aerobic Gram-negative Bacilli

OBJECTIVE: The evaluation of the new miniaturized CrystalTM Rapid Stool/Enteric System (Becton-Dickinson, USA) for identification of aerobic gram-negative bacilli. METHODS: a total of 154 clinical organisms (Enterobacteriaceae: 120 strains; oxidase-positive fermenters: 13 strains; non-fermenters: 21 strains) were tested. Results were compared with those obtained with the PASCOR system (Difco, USA) and divergent identifications were evaluated by standard biochemical tests. RESULTS: without additional testing, correct identification was obtained for 146 strains (Enterobacteriaceae: 95%; oxidase-positive fermenters 87%; non-fermenters 100%). For adequate identification of Yersinia enterocolitica strains, however, panels had to be incubated for 5 instead of 3 hours. CONCLUSIONS: the CrystalTM Rapid Stool/Enteric system offers a safe, accurate and rapid method for the identification of frequent isolates of the family Enterobacteriaceae and bacterial stool pathogens.