In vitro activity of ceftobiprole, daptomycin, linezolid, and vancomycin against methicillin-resistant staphylococci associated with endocarditis and bone and joint infection.

We tested the in vitro activity of 4 antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci recovered from patients with endocarditis or bone and joint infection. Ceftobiprole, daptomycin, linezolid, and vancomycin MIC(90) values were 1, 1, 2, and 1 microg/mL, respectively. Ceftobiprole, daptomycin, linezolid, and vancomycin MBC(90) values were 2, 4, > or = 128, and 8 microg/mL, respectively. Ceftobiprole MIC and MBC values were < or = 2 microg/mL for all isolates tested, with the exception of one methicillin-resistant coagulase-negative Staphylococcus spp isolate. Vancomycin lacked bactericidal activity (defined as an MBC/MIC ratio of > or = 32) against 2 methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients with bone and joint infection; one of these isolates was additionally daptomycin nonsusceptible (daptomycin MIC, 2 microg/mL). There was one additional daptomycin nonsusceptible (daptomycin MIC, 2 microg/mL) isolate (MRSA associated with bone and joint infection). Ceftobiprole demonstrated in vitro bactericidal activity against all MRSA and methicillin-resistant coagulase-negative staphylococci tested.