Evaluation of the BD Phoenix Automated Microbiology System SMIC/ID-2 Panel for Antimicrobial Susceptibility Testing of Streptococcus pneumoniae / 대한진단검사의학회지

ABSTRACT

BACKGROUND: With the emergence of antimicrobial resistance among Streptococcus pneumoniae, a more accurate and automated antimicrobial susceptibility testing method is essential. We evaluated the BD Phoenix Automated Microbiology System (Becton Dickinson Diagnostic Systems, USA) SMIC/ID-2 panel for antimicrobial susceptibility testing of S. pneumoniae. METHODS: A total of 113 clinical strains of S. pneumoniae (88 penicillin susceptible strains, 8 intermediate strains, and 17 resistant strains by 2008 CLSI criteria) were tested. Minimum inhibitory concentrations (MICs) for penicillin, cefotaxime, clindamycin, erythromycin, levofloxacin, trimethoprim/ sulfamethoxazole, tetracycline, and vancomycin were determined by Etest (AB Biodisk, Sweden) and Phoenix System. The results obtained by Phoenix system were compared to those obtained by Etest. RESULTS: The overall essential agreement of MICs (within one dilution of MICs) defined by the Phoenix and Etest was 92.3%. Neither very major errors nor major errors were produced, and minor errors were 6.5%. Minor errors were frequently observed in susceptibility testings for penicillin (22.1%), cefotaxime (12.4%), and trimethoprim/sulfamethoxazole (11.5%). CONCLUSIONS: The Phoenix SMIC/ID-2 panel provided a simple and rapid susceptibility testing for S. pneumoniae, and the results were in a good agreement with those of Etest. The Phoenix system appears to be an effective automated system in clinical microbiology laboratories.