ampicillin + ceftaroline fosamil

A dual β-lactam antibiotic combination therapy consisting of ampicillin and ceftaroline fosamil. This combination demonstrates synergistic activity against Enterococcus faecalis, including strains with high-level aminoglycoside resistance. The synergistic mechanism is mediated through differential penicillin binding protein (PBP) affinities between these two drugs, which leads to greater saturation of more PBP subtypes, thereby maximally inhibiting bacterial cell wall synthesis. Ceftaroline has affinity for a broad range of Gram-positive PBPs, including PBP5 of enterococci, which can be overexpressed in strains with reduced susceptibility to ampicillin. This combination has been studied as an alternative to ampicillin plus ceftriaxone for serious E. faecalis infections such as endocarditis.