Modified Procedure to Inoculate Micro-ID

The accuracy of a miniaturized Enterobacteriaceae system (Micro-ID) was evaluated with 10 different genera grown on 11 selective plating media. Whenever growth occurred, the correct identification was made. In addition, 12 serotypes of Salmonella and 22 other strains of Enterobacteriaceae were grown on the two most common selective media used by food microbiologists for isolation of Salmonella [Brilliant Green Sulfa Agar (BGS) and Bismuth Sulfite Agar (BiS)]. The correct identification was made in all instances. The manufacturer of Micro-ID originally recommended that several colonies be picked for inoculation of the system. We modified the inoculation procedure so that only one colony was selected from a plate; this minimized the chances of having a mixed-culture inoculum. With this procedure, all 21 Enterobacteriaceae tested were correctly identified.