Standardization of the Analytab Enteric (API 20E) system to increase accuracy and reproducibility of the test for biotype characterization of bacteria.

Procedures employing the Analytab Enteric (API 20E) system were standardized to improve the accuracy and reproducibility of the individual biochemical tests so that the system could be used to biochemically characterize bacteria for epidemiological studies. The standardized method and the method recommended by the manufacturer (routine method) were tested in parallel with 130 clinical isolates. Tests with 100 randomly selected clinical isolates demonstrated that the standardized method was more accurate and reproducible than the routine method. In addition, the standardized method accurately identified 24 of 30 clinical isolates which could not be identified with the routine method.