Comparison of Micro-ID, a modified Minitek system, and conventional methods for four-hour identification of...

The Micro-ID system and a four-hour modification of the Minitek system were compared to conventional tube media for identification of Enterobacteriacae directly from blood cultures. A total of 205 organisms representing 19 species were evaluated in the study. Of these, 151 were blood culture isolates and the remaining 54 were reference strains or other clinical isolates used in simulated cultures. Pellets of bacteria obtained by centrifuging aliquots of blood cultures were inoculated into Micro-ID and Minitek and incubated four hours at 36C. Compared to conventional methods, Micro-ID correctly named the genus and species of 195 (95.1%) of the isolates. Identification errors were related to the code manual and to some biochemical tests. The four-hour Minitek system agreed with conventional methods on the identification of 196 (95.6%) of the isolates. Although both methods were comparable in their ability to accurately identify enterics directly from blood cultures, Micro-ID had design features that made it more convenient for busy clinical laboratories.