Antibacterial activity of cefmetazole alone and in combination with fosfomycin against methicillin- and cephem-resistant Staphylococcus aureus.
AUTOR(ES)
Utsui, Y
RESUMO
In vitro and in vivo antibacterial activities of cefmetazole alone and in combination with fosfomycin against methicillin- and cephem-resistant (MR) strains of Staphylococcus aureus were investigated, and the mechanism of synergistic effect between cefmetazole and fosfomycin was also studied. Cefmetazole inhibited the growth of 71 strains of MR S. aureus at concentrations ranging from 1.56 to 50 micrograms/ml; the antibacterial activity of cefmetazole against these strains was enhanced approximately 4 times with the addition of fosfomycin at a concentration of 1.56 micrograms/ml. The binding affinity of cefmetazole for the penicillin-binding protein 2' fraction specific for MR S. aureus was higher than that of methicillin, cloxacillin, cefazolin, and cefotaxime. A synergy experiment in vitro was performed by checkerboard titration with Mueller-Hinton agar plates containing various concentrations and ratios of cefmetazole and fosfomycin. The fractional inhibitory concentration index ranged from 0.09 to 0.75. Exposure of cefmetazole plus fosfomycin to exponentially growing cultures at a concentration at which both antibiotics had no bactericidal effect when given alone exerted bactericidal action. Combined administration of cefmetazole with fosfomycin at a ratio of 1:1 against systemic MR S. aureus infections with mice showed an excellent therapeutic efficacy as compared with administration of either antibiotic alone. Penicillin-binding protein 2', 2, and 4 fractions were scarcely detectable in MR S. aureus strains grown in the presence of fosfomycin at concentrations of 0.25 MIC and 0.5 MIC, respectively.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=180619Documentos Relacionados
- Role of an altered penicillin-binding protein in methicillin- and cephem-resistant Staphylococcus aureus.
- In vitro activity of fosfomycin, alone and in combination, against methicillin-resistant Staphylococcus aureus.
- Combination of minocycline and rifampicin against methicillin- and gentamicin-resistant Staphylococcus aureus
- Activity of ciprofloxacin against methicillin-resistant Staphylococcus aureus.
- Bactericidal activity of antiseptics against methicillin-resistant Staphylococcus aureus.