In vitro susceptibility of Mycobacterium tuberculosis isolates to an oral carbapenem alone or in combination with ß-lactamase inhibitors.

We evaluated the antituberculosis (anti-TB) activity of five ß-lactams alone or in combination with ß-lactamase inhibitors against 41 clinical isolates of Mycobacterium tuberculosis, including multidrug-resistant and extensively drug-resistant strains. Of those, tebipenem, an oral carbapenem, showed the most potent anti-TB activity against clinical isolates, with a MIC range of 0.125 to 8 µg/ml, which is achievable in the human blood. More importantly, in the presence of clavulanate, MIC values of tebipenem declined to 2 µg/ml or less.