Identification of environmental staphylococci and coliforms by the Vitek Auto Microbic System

The Vitek Auto Microbic System (AMS) automated identification device was used in rapid identification of staphylococci and coliforms originating from food factory environments. From a total of 3324 isolates, an average of 76% were identified with a confidence > 50% (staphylococci: 61%, coliforms: 82%). AMS identifications of presumed staphylococci did not match well (24%) with ATB 32 STAPH identifications, but coliforms matched for 80% of the isolates compared with the API 20 E system. The differences observed between the AMS and ATB 32 STAPH in identifications could be due to inadequate isolation media, insufficient isolate purification, incorrect pre-screening of isolates or an incompetent AMS database. For coliforms, the overall performance proved sufficient for rapid screening of isolates from food factory bacterial ecology studies.