Evaluation of the OSIRIS video reader as an automated measurement system for the agar disk diffusion technique.

Measurement of inhibition zones by the automated OSIRIS system was compared with manual measurement. In total, 14 176 measurements were made with 352 staphylococcal and 80 Enterobacteriaceae isolates, involving four panels of antibiotics on round and square Mueller-Hinton agar plates, according to the German DIN 58940 recommendations. Variations of +/- 3 mm in zone size measurements were defined as tolerable.