Gepotidacin mesylate dihydrate (GSK2140944 mesylate dihydrate) is an orally available triazaacenaphthylene antibiotic with antibacterial activity. Gepotidacin mesylate dihydrate is an inhibitor of bacterial type II topoisomerase. Gepotidacin mesylate dihydrate inhibits bacterial DNA replication by blocking topoisomerase and can be used to study bacterial infection.