Fig. 3

Linezolid (LNZ) (a) and vancomycin (VAN) (b) concentration in plasma, ETA, and ETT biofilm. In plasma at ETA, LNZ and VAN levels are at 72 h after treatment initiation, in ETT biofilm at extubation. Each dot represents drug concentration of each sample included into the treatment groups. Black central lines depict median value. LNZ median MIC (IQR) was 1.50 [0.88–3.00] μg/mL, while VAN median MIC was 0.75 [0.5–1] μg/mL. The median LNZ and VAN MIC values of the MRSA isolates are indicated by the horizontal gray dashed line while the gray bands represent the 25th–75th percentile ranges in each graph. Of note, LNZ presented high concentrations in ETA and ETT biofilm while VAN concentration fell drastically in ETA and ETT biofilm, to non-therapeutic concentrations. a Plasma vs ETA, p = 0.039; plasma vs ETT biofilm, p = 0.050. b Plasma vs ETA, p = 0.021; plasma vs ETT biofilm, p < 0.001. ETT, endotracheal tube; ETA, endotracheal aspirates; MRSA, methicillin-resistant Staphylococcus aureus; MIC, minimum inhibitory concentration