Evaluation of the MicroScan system for identification of staphylococci

Conventional biochemical tests were compared with reactions in a multiple test system, MicroScan Walkaway (Dade Diagnostic Inc. MicroScan Divison, West Sacramento, California) in conjugation with the Combo Pos ID Panels (Dade Diagnostic Inc. MicroScan Divison, West Sacramento, California), in order to evaluate the accuracy for the identification of 99 clinical isolates of Staphylococcus spp. and five reference strains. False-negative or positive reactions were detected from Voges-Proskauer, urease and mannose tests. A good correlation was found among the two identification systems for the fermentation of trehalose, lactose, raffinose, as well as for arginine dyhydrolase, esculin hydrolisis and nitrate reduction. From the results of the present study, it is concluded that the MicroScan Walkaway system is a reliable method for identification of staphylococci (94.23%), although 8.2% could be identified to the species level only after use of additional test.