Patent ID: 7897400

Claim:
A method for diagnosing the presence of Mycobacterium tuberculosis in the lungs or other tissues of a patient or subject, including the steps of: (a) administering effective amounts of isotopically labeled isoniazid and/or urea to the patient or subject, said isoniazid and said urea being cleavable by M. tuberculosis to provide at least one isotopically labeled cleavage product in the breath of said patient or subject, said cleavage product being selected from the group consisting of nitric oxide, ammonia carbon monoxide, carbon dioxide and mixtures thereof; (b) collecting breath samples from the patient or subject; and (c) analyzing said samples to determine a concentration or concentrations of said cleavage product(s), said concentration(s) indicating the presence or absence of M tuberculosis including optionally, the presence of isoniazid resistant M.tuberculsosis in the lungs or other tissues by virtue of isoniazid-resistant M. tuberculosis not cleaving isoniazid.