(5R)-3-[4-[1-[(2S)-2,3-dihydroxypropanoyl]-3,6-dihydro-2H-pyridin-4-yl]-3,5-difluoro-phenyl]-5-(isoxazol-3-yloxymethyl)oxazolidin-2-one, or a pharmaceutically-acceptable salt, or an in-vivo-hydrolysable ester thereof, for use in the treatment of Mycobacterium tuberculosis.