Histologic score ranging from 0 to 3, based on the degree of polymorphonuklear infiltration, haemorrhage, and oedema in the interstitial and alveolar spaces, following tracheal instillation of saline (controls) or 9 log10CFU of Staphylococcus aureus in either spontaneously breathing rabbits or animals subjected to mechanical ventilation with various treatment combinations. Mean values (SD) are shown (A) as well as representative light microphotographs of rabbit lungs in various conditions fixed at the same transpulmonary pressure (hematoxylin and eosin x400) (B). Two-tailed Mann-Whitney U test was used for all intergroup comparisons. CFU: colony forming unit; MRSA: methicilline-resistant S. aureus; LNZ: linezolid; SB: spontaneously breathing; MV: mechanical ventilation; SD: standard deviation.