Capture and Visualization of Live Mycobacterium tuberculosis Bacilli from Tuberculosis Patient Bioaerosols

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the leading infectious killer globally, claiming 1.4 million lives annually. TB control is heavily predicated on treatment of active disease. However, delayed and missed diagnoses, and the six-month duration of standard chemotherapy, contribute to failure of this approach to control the TB epidemic. Enumeration of viable aerosolized Mtb via microbiological culture is complicated by the semi-quantitative nature of "time to positivity" in liquid culture and the slow formation of Colony Forming Units on solid media (four to eight weeks for colonies to become visible). A key motivation informing the development of the RASC platform was the need to capture live, aerosol-derived Mtb for analysis and propagation as part of a larger research program in TB transmission and Mtb aerobiology. Fluorescence microscopy of bioaerosol samples enabled the detection of putative live Mtb in 90% of GeneXpert-confirmed TB patients.