Antimicrobial agents and chemotherapy
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Antimicrob. Agents Chemother. · Jul 2009
Comparative StudyComparison of tigecycline and vancomycin for treatment of experimental foreign-body infection due to methicillin-resistant Staphylococcus aureus.
Twice-daily 7-day regimens of tigecycline (7 mg/kg) and vancomycin (50 mg/kg) were compared in a rat tissue cage model of chronic foreign-body infection due to methicillin (meticillin)-resistant Staphylococcus aureus strain MRGR3. Subcutaneously administered tigecycline reached levels in tissue cage fluid that were nearly equivalent or slightly superior to the antibiotic MIC (0.5 microg/ml) for strain MRGR3. After 7 days, equivalent, significant reductions in bacterial counts were recorded for tigecycline-treated and vancomycin-treated rats, compared with those for untreated animals.
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Antimicrob. Agents Chemother. · Jul 2009
Efficacy of daptomycin in implant-associated infection due to methicillin-resistant Staphylococcus aureus: importance of combination with rifampin.
Limited treatment options are available for implant-associated infections caused by methicillin (meticillin)-resistant Staphylococcus aureus (MRSA). We compared the activity of daptomycin (alone and with rifampin [rifampicin]) with the activities of other antimicrobial regimens against MRSA ATCC 43300 in the guinea pig foreign-body infection model. The daptomycin MIC and the minimum bactericidal concentration in logarithmic phase and stationary growth phase of MRSA were 0.625, 0.625, and 20 microg/ml, respectively. ⋯ In addition, daptomycin at a high dose (30 mg/kg) completely prevented the emergence of rifampin resistance in planktonic and adherent MRSA cells. Daptomycin at a high dose, corresponding to 6 mg/kg in humans, in combination with rifampin showed the highest activity against planktonic and adherent MRSA. Daptomycin plus rifampin is a promising treatment option for implant-associated MRSA infections.
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Antimicrob. Agents Chemother. · Jul 2009
Combination of daptomycin plus ceftriaxone is more active than vancomycin plus ceftriaxone in experimental meningitis after addition of dexamethasone.
We examined the cerebrospinal fluid penetration of daptomycin after the addition of dexamethasone and its bactericidal efficacy with and without ceftriaxone in an experimental rabbit model of pneumococcal meningitis. The combination of daptomycin with ceftriaxone was the most efficacious regimen for pneumococcal meningitis. The previous addition of dexamethasone affected the antibacterial activity of daptomycin only marginally, either as monotherapy or combined with ceftriaxone, although the penetration of daptomycin into inflamed meninges was significantly reduced from 6 to 2%. Daptomycin with ceftriaxone might be a potential candidate for the empirical therapy of bacterial meningitis, although the activity of this regimen against Listeria monocytogenes remains to be demonstrated.