Surveillance for linezolid resistance via the Zyvox^®Annual Appraisal of Potency and Spectrum (ZAAPS) programme (2014): evolving resistance mechanisms with stable susceptibility rates

Abstract

These results document the continued long-term and stable in vitro potency of linezolid and reveal a limited number of isolates with decreased susceptibility to linezolid (i.e. MIC ≥4 mg/L). The latter isolates primarily showed mutations in the 23S rRNA gene and/or L3 protein, but cfr was not detected. Moreover, this study shows that isolates carrying the newly described ABC transporter optrA are not restricted to China.