So to go further, we first conduct a phenotypic analysis in order to establish the incidence of this resistance, in accordance with the 2016 EUCAST criteria. Association with genotypic analysis using Pulsed-field gel electrophoresis and Multilocus-sequence typing will allow underlining the impact of the presence of the crf gene, and mutations described as being involved in high level resistance (mutations in domaine V of 23S ARN or ribosomal proteins L3 and L4).