MRSA with linezolid tolerance

I came across an article the other day that describes an infection of S. aureus that could not be cured with Linezolid. It was a 68-year-old woman who remained febrile throughout her hospital stay and died from massive PE on day 18. From the abstract:

Antimicrobial “tolerance” is defined as a wide discrepancy between the minimal inhibitory concentration and the minimal bactericidal concentration of an isolate. Tolerance was first described in S. aureus and has since been described with streptococci and enterococci. Despite apparent in vitro susceptibility, infections caused by “tolerant” strains are not cured by appropriate antimicrobial therapy. The lack of bactericidal activity of the antibiotic becomes apparent when minimal bactericidal concentrations are determined for “tolerant” strains, and there is a great discrepancy between the minimal inhibitory concentration being used. Antibiotic tolerance to S. aureus has been described with a variety of antibiotics. To the best of our knowledge, this is the first case of continuous, high-grade methicillin-resistant S. aureus bacteremia due to a linezolid-tolerant strain.

1. B CUNHA, N MIKAIL, L EISENSTEIN (2008). Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia due to a linezolid “tolerant” strain Heart & Lung: The Journal of Acute and Critical Care, 37 (5), 398-400 DOI: 10.1016/j.hrtlng.2007.12.001