Grillon A, Argemi X, Gaudias J, et al. - Fourteen adult individuals hospitalized with diabetic foot infections (DFI) treated with daptomycin (a cyclic lipopeptide antibiotic with rapid and concentration-dependent bactericidal activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and multidrug-resistant enterococci) and who needed surgical bone debridement and amputation were involved in a single-center prospective study by the researchers in order to discover daptomycin bone concentrations in patients with DFI who underwent surgery following multiple daptomycin infusions and to ascertain bone daptomycin inhibitory quotients (IQs) for the predominant gram-positive species involved in DFI. Residual and peak concentrations ranged from 4.5 mg/l to 39.9 mg/l and from 31.8 mg/l to 110.9 mg/l, respectively. At the moment of surgery, bone daptomycin concentrations ranged from 1.2 mg/l to 17 mg/l. All bone daptomycin IQs were noted to be positive up to a minimum inhibitory concentration (MIC) of 1 mg/l, which was the epidemiological cut-off value (ECOFF) and breakpoint value for S aureus and coagulase-negative staphylococci. Staphylococcus species had the highest bone IQ. Near the ECOFF, calculated bone IQs for Enterococcus species were usually weak at MIC values. Therefore, in patients treated for DFI, daptomycin perforated bone well. Moreover, due to low-MIC Enterococcus, bone concentrations were inclined to be efficient against staphylococcal infections and infections at an initially suggested dosage of 6 mg/kg.