Fidaxomicin

Fidaxomycin is a natural macrocyclic antibiotic and RNA polymerase inhibitor that displays selectivity for Gram-positive bacteria over Gram-negative bacteria (IC₅₀s = 0.4 and 6 μM, respectively). It shows potent antibacterial activity against most Gram-positive bacteria and effectively targets the Gram-positive C. difficile (MIC = 12 ng/ml). Also shown to have excellent bactericidal activity against multidrug-resistant Mycobacterium tuberculosis.