Novel Antibiotic Combinations of Diverse Subclasses for Effective Suppression of Extensively Drug-Resistant Methicillin-Resistant Staphylococcus aureus (MRSA)

Figure 2

Triple antibiotic testing against MRSA. (a) List of triple combinations. (b) Amoxicillin-clavulanic acid-cephalosporin MIC indicates that synergistic relationship exists only between amoxicillin-clavulanic acid-cephradine (FICI 0.281). (c) MIC of amoxicillin-clavulanic acid-fluoroquinolone combination shows that synergy exists in all combinations (FICI 0.25 each). (d) A significant decrease in MIC of amoxicillin-clavulanic acid-aminoglycoside in combinations (FICI 0.125). (e) Reduction in combined MIC is only observed with moxifloxacin in piperacillin-tazobactam-fluoroquinolone combinations (FICI 0.281). (f) Significant activity is observed when piperacillin-tazobactam is combined with higher-generation aminoglycoside, i.e., tobramycin (FICI 0.281) and fosfomycin (FICI 0.281). (g) Meropenem in combination with piperacillin-tazobactam exhibits synergy (FICI 0.375).

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