A method for targeted enrichment of Mycobacterium tuberculosis transcriptome in sputum

Measurement of the M.tuberculosis (Mtb) RNA transcriptome in sputum has potential for evaluating treatment response and pathways of drug resistance in clinical drug development, but Mtb RNA sequencing of sputum samples is not possible due to the dominance of human RNA. We evaluated whether a method of enriching Mtb RNA in sputum samples using biotinylated-RNA oligonucleotides could enable satisfactory RNA sequencing. RNA sequencing was successful, with 74-79% gene coverage in sputum samples and detected transcriptome changes related to drug resistance mutations. This approach may be of value in future research applications.