Clonal dissemination of linezolid-resistant Staphylococcus capitis with G2603T mutation in domain V of the 23S rRNA and the cfr gene at a tertiary care hospital in China

BACKGROUND: The present study aims to investigate the potential mechanism of linezolid-resistant Staphylococcus capitis (LRSC) isolates collected from our hospital. METHODS: The susceptibilities of 5 Staphylococcus capitis isolates displaying resistance towards linezolid were determined by E-test. Polymerase chain reactions (PCRs) and DNA sequencing were used to investigate the potential molecular mechanism. Clonal relatedness between these strains was analyzed by pulsed-field gel electrophoresis (PFGE). RESULTS: The MICs of linezolid on these 5 isolates were >256 μg/mL. The G2603T mutation was observed in the domain V of the 23S rRNA with cfr gene being also widely detected among these 5 strains. PFGE analysis displayed close genetic relatedness between these linezolid-resistant isolates. CONCLUSIONS: The emergence of LRSC isolates carrying G2603T mutation in the domain V of the 23S rRNA and harboring cfr gene in our hospital may pose a potential challenge to the public health.