Importance of carbohydrate tests for interspecies differentiation of staphylococci

: The authors present the results of interspecies identification of coagulaso-negative staphylococci isolated from different sources. Modification of the method of aerobic carbohydrate and alcohols fermentation of hard media is described. Use of the latest recommendations of the International Subcommittee on taxonomy of staphylocossi and micrococci permitted to identify the greater part of 120 strains studied as Staph. epidermidis and Staph. saprophyticus; however, 1/3 of the cultures differed from these species ("intermediate" strains). Galactose and mannose fermentation was characteristic of Staph. epidermidis, and the absence of fermentation of these carbohydrates--of Staph. saprophyticus. The differences in the fermentation of mannite and tregalose, on the one hand, and on mannose and galactose--on the other, were characteristic of 57% of the "intermediate" strains. The data obtained permitted to draw a conclusion on nonhomogeneity of the group of coagulase-negative staphylococci by their reference to different carbohydrates and alcohols, and on a possibility of existence of not only of different species of these staphylococci, but also of their biochemical variants.