Evaluation of the BD Phoenix Automated Microbiology System for Identification and Antimicrobial Susceptibility Testing of Common Clinical Isolates

Abstract

Objective: To evaluate the accuracy and reliability of the BD Phoenix Automated Microbiology System for identification (ID) and antimicrobial susceptibility testing (AST) of Gram-positive and Gram-negative isolates. Materials and Methods: The ID of 291 Gram-negative and 158 Gram-positive clinical isolates were evaluated by the system. The AST of 252 Gram-negative and 151 Gram-positive isolates with correct ID were then evaluated. The results were compared with those of the API ID system and the microbroth dilution method. All discrepant results were repeated for verification. Results: Over 90% Gram-negative and Gram-positive isolates were correctly identified to species or genus level by the Phoenix system. The minimum inhibitory concentration agreement rates between the Phonenix and the microbroth dilution methods within ±1 dilution ranged from 87.3 to 97.6% for Gram-negative isolates, and from 50 to 100% for Gram-positive isolates. For Gram-positive isolates, vancomycin had significant low minimum inhibitory concentration agreement rates. Conclusions: Overall, the results indicate that the Phoenix system is a reliable system. It could provide accurate ID and AST results for routine clinical laboratories.