Performance of BD phoenix in identification and susceptibility testing of Streptococcus pneumoniae

Abstract

The performance of the BD Phoenix SMIC/ID8 Streptococcus Panel (BDSP) for identification (ID) and susceptibility testing of Streptococcus pneumoniae (S. pneumoniae) was compared to the Clinical and Laboratory Standards Institute (CSLI) method. Mutations of penicillin-binding protein (PBP) genes were detected by polymerase chain reaction (PCR), and the minimum inhibitory concentrations (MIC) values obtained from BDSP were compared with the PCR results. To identify bacterial isolates, the concordance rate to those with autolysin gene was 97.1%. The MIC50 and MIC90 with the BDSP and CLSI method were in close agreement in non-mutants and single PBP mutants. However, when the number of PBP mutations increased, MICs increased further and demonstrated resistance to penicillin (PEN) in particular. Thereby, MICs by BDSP were higher than those by the CLSI method (P<0.05). Thus, the BDSP panel is superior to the CSLI method for the detection of S. pneumoniae resistance.