Activity of the new cephalosporin ceftaroline against bacteraemia isolates from patients with community-acquired pneumonia

Abstract

The activity of ceftaroline, a novel cephalosporin, was evaluated against 1337 isolates from patients with bacteraemic community-acquired pneumonia (CAP) requiring hospitalisation (including 119 Haemophilus influenzae, 9 Moraxella catarrhalis, 164 Staphylococcus aureus, 1007 Streptococcus pneumoniae and 38 Streptococcus pyogenes). Minimum inhibitory concentrations (MICs) were determined by broth microdilution according to Clinical and Laboratory Standards Institute (CLSI) guidelines, and susceptibility category assessments were made using CLSI or US Food and Drug Administration (FDA) breakpoints. Ceftaroline MICs were ≤0.008–0.06 mg/L against H. influenzae, 0.25–2 mg/L against methicillin-resistant S. aureus (MRSA), 0.06–1 mg/L against methicillin-susceptible S. aureus, 0.015–0.5 mg/L against M. catarrhalis and ≤0.008–0.5 mg/L against S. pneumoniae, and all S. pyogenes isolates had ceftaroline MICs ≤0.008 mg/L. Ceftaroline was more active than ceftriaxone or cefepime both against MRSA and penicillin-resistant pneumococci. More than 90% of MRSA isolates were resistant to clarithromycin and levofloxacin but were susceptible to linezolid or tigecycline. A high rate of clarithromycin resistance was also observed in the pneumococci. Ceftaroline was very active in vitro against all CAP isolates, including MRSA and penicillin-non-susceptible pneumococci, in contrast to the other β-lactams tested. These data confirm ceftaroline as a new cephalosporin with enhanced anti-Gram-positive activity and suggest that ceftaroline has the potential to be a useful new agent in the treatment of CAP-associated bacteraemic infections.