The in vitro effects of faropenem on lower respiratory tract pathogens isolated in the United Kingdom

Faropenem is a new oral penem with a structure different from current β-lactams including carbapenems. The susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to faropenem, a macrolide, a β-lactam, a β-lactam/β-lactamase inhibitor combination and two fluoroquinolones was investigated. S. pneumoniae was the most susceptible of the three species to faropenem. The MIC₉₀s of faropenem against M. catarrhalis and H. influenzae were 0.5 and 1 mg/l, respectively. They were similar to amoxiclav (MIC ₉₀s of 0.25 and 0.5 mg/l). The quinolones showed strong activity against H. influenzae. A cluster analysis of the activities of amoxycillin and faropenem demonstrated a direct relationship between the two antimicrobial agent's activities and resistance profiles against both S. pneumoniae and H. influenzae.