Excellent performance of CHROMagarTM LIN-R to selectively screen for linezolid-resistant enterococci and staphylococci

•Performance of a chromogenic screening agar called CHROMagarTM LIN-R was assessed.•CHROMagarTM LIN-R was challenged with linezolid-resistant staphylococci (n = 68) and enterococci (n = 36).•The agar revealed a specificity of 100% and a sensitivity of 99%.•Species prediction from colony color on CHROMagarTM LIN-R plates was possible. The increasing number of nosocomial pathogens with resistances against last resort antibiotics like linezolid leads to a pressing need for the reliable detection of these drug-resistant bacteria. National guidelines on infection prevention, e.g., in Germany, have already recommend screening for linezolid-resistant bacteria, although a corresponding screening agar medium has not been provided. In this study we analyzed the performance and reliability of a commercial, chromogenic linezolid screening agar. The medium was capable to predict more than a hundred linezolid-resistant isolates of E. faecium, E. faecalis, S. aureus, S. epidermidis, and S. hominis with excellent sensitivity and specificity. All isolates were collected at the National Reference Centre between 2010 and 2020.