Inability to adequately control antimicrobial agents on AutoMicrobic System Gram-Positive and Gram-Negative Susceptibility Cards.

The Vitek Gram-Positive Susceptibility Card (GPS) and Gram-Negative General Susceptibility Plus Card (GSC Plus) were tested on the AutoMicrobic System (AMS) 50 times each with the recommended control organisms. Only 1 drug (chloramphenicol) of 11 on the GPS and 1 (gentamicin) of 10 on the GSC Plus could be adequately controlled, leaving unsubstantiated the results obtained with patient isolates on the remaining 19 antimicrobial agents.