This is consistent with prior studies and not particularly earthshaking, but if you needed more literature to support switching antibiotics in the case of treatment failure, this would be another one.
This is in pigs, and it's an animal model of MRSA ventilator-associated pneumonia. Four groups - controls, twice-daily vancomycin, continuous vancomycin infusion, and linezolid. Treatment was initiated after 12 hours of bacterial inoculation in ventilated pigs. At the end of their 96 hour treatment period, 75% of controls, 11% of each vancomycin group, and 0% of linezolid pigs were BAL positive for MRSA by culture. Likewise, pathologic sections also showed decrease inflammation and damage in the linezolid group.
Short story, linezolid is better - but not quite better enough that we can't still start with vancomycin and keep it in reserve.
Sponsored by Pfizer and Eli Lilly.
"Efficacy of linezolid compared to vancomycin in an experimental model of pneumonia induced by methicillin-resistant Staphylococcus aureus in ventilated pigs"