Background: The MicroScan MICroSTREP plus panel for susceptibility testing of various streptococci, including Streptococcus pneumoniae, has recently been introduced in Korea. The current study evaluated the usefulness of MicroScan MICroSTREP plus panel for antimicrobial susceptibility test of S. pneumoniae.

Methods: A total of 75 clinical isolates of S. pneumoniae were tested for antimicrobial susceptibility to penicillin, cefotaxime, ceftriaxone, meropenem, vancomycin, clindamycin, erythromycin, and levofloxacin with the MicroScan MICroSTREP plus panel and clinical and laboratory standard institute (CLSI) reference broth microdilution method. For 46 of 75 isolates, additional susceptibility tests to penicillin and cefotaxime were performed with Etest.

Results: The overall essential agreement of MICs (within one dilution of MICs) defined by the MicroScan MICroSTREP plus panel and reference method was 93.0%. Overall there were 11.7% minor, 0.7% major, and 0.7% very major interpretative category errors observed. The results of antibiotic susceptibility testing by Etest were similar to those obtained by the MicroScan MICroSTREP plus panel.

Conclusion: The MicroScan MICroSTREP plus panel, a commercial broth microdilution method, has a comparable accuracy to CLSI broth microdilution method for the resistance testing of S. pneumonia. This panel can be used for determining susceptibilities of S. pneumoniae to a wide variety of antimicrobial agents in clinical microbiology laboratories. (Korean J Clin Microbiol 2008;11:18-22)