Reproducibility of API Staph-Ident system identifications of coagulase-negative staphylococci isolated from blood.

Fifty-five isolates of coagulase-negative staphylococci from blood were identified four times each by using the API Staph-Ident (API-SI) system to determine the identification reproducibility of the system. Identifications were determined by using both Version 1 and Version 2 of the API-SI Profile Index. The 75 to 100% reproducibility levels, including reproducible nonidentifications, were 98.2% for Version 1 and 96.4% for Version 2. Version 1 gave an identification for 92.5% of the isolates with a 75 to 100% reproducibility, while Version 2 gave an identification for 100% of the isolates with a 75 to 100% reproducibility. The reproducibility of the API-SI identifications of coagulase-negative staphylococci from blood was good.