Cost-effective, clinically relevant method for rapid identification of beta-hemolytic streptococci and enterococci.

Currently popular agglutination and coagglutination methods for the identification of beta-hemolytic streptococci, although rapid and simple to perform, are costly. Furthermore, they fail to distinguish between clinically relevant species and normal flora of the same serogroup. We investigated the use of a series of four physiologic tests to differentiate beta-hemolytic streptococci and enterococci into five clinically relevant groups. We also investigated the use of a new product, Visi-Spot, and evaluated an alternate method for the detection of beta-D-glucuronidase production. Our results suggest that for most routine processing of beta-hemolytic streptococci, physiologic tests are sufficiently rapid, more accurate, and far less costly to perform than serologic methods. The facility of our scheme is enhanced by the use of the Visi-Spot test and the substitution of a commercially available product for more traditional methods of detecting beta-D-glucuronidase.