Bone and joint infections are commonly due to Gram-positive bacteria. Treatment of these infections is difficult because of the need of prolonged duration of antimicrobial agents in combination with surgical procedure. Moreover, in recent years, a growing resistance pattern to various antimicrobial agents has been observed for Gram-positive bacteria. Consequently, there is an urgent need for new drugs with high bone penetration for the treatment of those infections. The investigators hypothesized that daptomycin allow to achieve high concentrations in bone compartments.

Inclusion criteria:

• Patient under treatment with daptomycin for more than 3 days with dosage at 6 mg/kg
• Patient undergoing imperative surgery with bone withdrawal
• Signed, and dated informed consent as defined by the Institutional Review Board
• Male and female patients older than 18 years of age
• Patients with social insurance
• Patient with information on previous mandatory medical examination

Exclusion criteria :

• Patient with no treatment by daptomycin or with a dosage < 6mg/kg or with less than 3 doses of daptomycine
• Patient with no need for surgery
• Patient younger than 18 years of age
• Pregnant and nursing women
• Patient refusal for inclusion
• Patients with deprived liberty
• Inability to complete the informed consent process because of problems with mental capacity

Patient under treatment with daptomycin and undergoing imperative surgery with bone withdrawal