Evaluation of the potential role of a new mutation in mabA in modifying the response of Mycobacterium tuberculosis to isoniazid.

A new mutation in mabA, Thr4Ile, was identified in a Mycobacterium tuberculosis isolate from a patient whose culture remained positive after treatment. The same mutation was found in another 5 patients infected by different strains. A putative role for this mutation in the process of diminishing susceptibility to isoniazid is evaluated.