Antibacterial Activity of Lefamulin against Pathogens Most Commonly Causing Community-Acquired Bacterial Pneumonia: SENTRY Antimicrobial Surveillance Program (2015-2016)

Lefamulin, the first semisynthetic pleuromutilin antibacterial for intravenous and oral treatment of community-acquired bacterial pneumonia (CABP), and comparators were evaluated for in vitro activity against a global collection of pathogens commonly causing CABP (n = 8595) from the 2015 and 2016 SENTRY Antimicrobial Surveillance Program. Lefamulin was highly active against the pathogens Streptococcus pneumoniae, including multidrug-resistant and extensively drug-resistant strains (MIC50/90 for total and resistant subsets, 0.06/0.12 mu g/ml; 100% inhibited at <= 1 mu g/ml), Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA; both MIC50/90, 0.06/0.12 mu g/ml; 99.8% and 99.6% inhibited at <= 1 mu g/ml, respectively), Haemophilus influenzae (MIC50/90, 0.5/1 mu g/ml; 93.8% inhibited at <= 1 mu g/ml), and Moraxella catarrhalis (MIC50/90, 0.06/0.12 mu g/ml; 100% inhibited at <= 0.25 mu g/ml), and its activity was unaffected by resistance to other antibacterial classes.