It currently takes up to two months to obtain the full diagnostic information for a patient with TB, as the bacteria grow very slowly in the laboratory. Scientists have sought for years to bypass this time-consuming step by examining the bacterial DNA directly from a sputum sample. However since most of the cells in sputum are human, it is difficult to spot the signal (TB DNA) within the noise (human and other bacteria) and even harder to find a method that might be affordable and practical across the world.
The new process, led by researchers from the University of Oxford and described in the Journal of Clinical Microbiology, rapidly processes the sputum to preferentially retain TB, using simple and relatively affordable materials, and then sequences and analyses the bacterial DNA. The Oxford team worked with researchers from the University of Nottingham, the Foundation for Medical Research, Mumbai, and Public Health England.