Diagnosis of tuberculosis by whole genome sequencing of DNA from sputum


Current screening of pulmonary tuberculosis (TB) via sputum microscopy only detects TB in 40-60% samples.

Phenotypic drug susceptibility testing (DST) can take weeks or months.

A faster test is available, but only predicts resistance to Rifampicin.

Next-generation sequencing such as nanopore can detect TB and predict DST profiles ‘at a much faster rate’, demonstrating future potential to reduce time-to-diagnosis & appropriate treatment for TB.

Sequencing DNA extracted directly from sputum performed on MinION, demonstrating detection of M. tuberculosis, lineage determination & DST profiling for 11 drugs, in samples with >0.2% M. tb reads.

‘Nanopore sequencing can detect M. tb DNA directly from sputum of different grades (3+, 2+ and 1+)’.

In future, Kayzad and team envision ‘nanopore sequencing as a point-of-care diagnostic tool’ for faster TB screening.

Authors: Kayzad Nilgiriwala