Mycobacterium tuberculosis fingerprint in human lungs

Tuberculosis (TB) is one of the top ten causes of death worldwide and the leading cause of death from a single infectious agent. Globally, an estimated of 10 million people developed TB in 2018 according to WHO report. An estimated one third of all TB cases are not diagnosed or notified, partly due to the major limitations of current diagnostic tools. To achieve the goals of the WHO’s End TB Strategy, which targets for 2030 a 90% reduction in the number of TB deaths and an 80% reduction in the TB incidence rate compared with levels in 2015, diagnostic tools are critically important. Among the three diagnostic priorities identified by the WHO and the TB community is the development of a point-of-care biomarker-based non-sputum-based test to diagnose pulmonary TB, and ideally also extrapulmonary TB. To be successfully implemented at point-of-cares, a new test should use an easily accessible sample, such as urine, blood or breath condensate. Here, we explored whether bacilli-derived molecules released in the extracellular milieu during infection could be detected in the exhaled breath condensate, allowing a specific diagnosis of TB. Interestingly, we detected by proteomic analysis a set of Mycobacterium tuberculosis proteins in all smear-positive and smear-negative adult patients, as well as of children with TB