title: In-vitro activity of ceftriaxone combined with newer agents against MRSA.
abstract: In this study, in vitro synergism in combinations of agents as ceftriaxone/dalbavancin, ceftriaxone/linezolid and ceftriaxone/daptomycin against MRSA strains were investigated. Thirty clinical MRSA strains were tested. The minimum inhibitory concentrations of all antibiotics were determined using reference broth microdilution method. In-vitro activities of antibiotics combined against the strains were tested using two-dimensional checkerboard microdilution method. Results were interpreted as follows: synergy = FICI ≤0.5; 'no interaction' effect = FICI ˃0.5-≤4; antagonism = FICI ˃4. The MIC50, MIC90and MICrangeof ceftriaxone, daptomycin, dalbavancin and linezolid were found as 128, 1024 and 16-2048 mg/L; 1, 1 and 0.5-1 mg/L; 0.12, 0.12 and 0.03-0.12 mg/L; and 1, 2 and 1-2 mg/L, respectively. Our results showed that the frequency of synergistic effects (FICI: ≤0.5) of three combinations were all at the same rate of 77% (23/30). No in vitro antagonism (FICI >4) was observed.
authors: a Istanbul Faculty of Medicine, Department of Medical Microbiology , Istanbul University , Istanbul , Turkey.
authors: Gulseren
authors: http://orcid.org/0000-0002-1611-5289
authors: G
authors: Aktas
mesh_terms: D002443:Ceftriaxone / Q000494:pharmacology*; D017576:Daptomycin / Q000494:pharmacology; D004357:Drug Synergism; D004359:Drug Therapy, Combination / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D000069349:Linezolid / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D017334:Teicoplanin / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D017334:Teicoplanin; D002443:Ceftriaxone; C469289:dalbavancin; D000069349:Linezolid; D017576:Daptomycin
keywords: Dalbavancin; Daptomycin; Linezolid; Methicillin-resistant Staphylococcus aureus; Synergistic effects of ceftriaxone combinations