Evaluation of the rapid Patho Dx Latex Strep Grouping Kit

A variety of clinical specimens from throat, nose, ear, eye, wounds, urine, and vagina were collected, cultured, and screened for beta-hemolytic streptococci. The Patho Dx Latex Strep Grouping Kit (Diagnostic Product Corp., Los Angeles, Calif.) technique was applied to colonies taken right from the primary cultures. Isolated strains were sent to the reference laboratory where they were grouped by standard techniques. The kappa coefficient of agreement between the Patho Dx Kit and the standard method was 0.958. We believe that, although better agreement was achieved by others with isolated colonies, a very good agreement is also achieved with primary cultures. The fact that the laboratory is able to report an accurate answer after only 24 h seems most advantageous.