Identification of viridans streptococci on the Minitek Miniaturised Differentiation System

A total of 227 strains of viridans streptococci were simultaneously identified on the Minitek Miniaturised System (BBL) and by a conventional method according to Colman and Williams. The Minitek discs were each overlaid with a drop of sterile liquid paraffin, and the trays were incubated in GaSPak jars (BBL) with CO2 generator envelopes. Identification was possible three to four days earlier than with the conventional method. The results were found to be in agreement with the conventional method. Compared to the identification schemes of Cowan and Steel and of Facklam, the results were also in good agreement. Minor differences were found in the number of positive and negative results in those reactions that are variable in all three schemes.