Preliminary interpretive zone criteria were calculated for cefetamet (Ro 15-8074) and cefteram (Ro 19-5247) by using 10- and 30-micrograms disks and three possible MIC susceptibility breakpoints. Absolute interpretive agreement between MICs and zone size criteria ranged from 91.8 to 97.2%. Very major errors (false susceptibility) were less than or equal to 1.2% for both cephalosporin disk tests...
