TB-QUICK: CRISPR-Cas12b-assisted rapid and sensitive detection of Mycobacterium tuberculosis.

Abstract Objectives Tuberculosis (TB) remains one of the public health problems worldwide. Rapid, sensitive and cost-effective diagnosis of Mycobacterium tuberculosis (M.tb) is critical for TB control. Methods We developed a novel M.tb DNA detection platform(nominated as TB-QUICK) which combined loop-mediated isothermal amplification (LAMP) and CRISPR-Cas12b detection. TB-QUICK was performed on pulmonary or plasma samples collected from 138 pulmonary TB (PTB) patients, 21 non-TB patients and 61 close contacts to TB patients. Acid-fast bacillus(AFB) smear, M.tb culture and GeneXpert MTB/RIF (Xpert) assays were routinely conducted in parallel. Results By targeting M.tb IS6110, TB-QUICK platform could detect as low as 1.3 copy/μL M.tb DNA within 2 hours. In pulmonary TB samples, TB-QUICK exhibited improved overall sensitivity of 86.8% over M.tb culture (66.7%) and Xpert (70.4%), with the specificity of 95.2%.More significantly, TB-QUICK exhibited a superior sensitivity in AFB-negative samples (80.5%) compared to Xpert (57.1%) and M.tb culture (46.2%). In the detection of plasma M.tb DNA by TB-QUICK, 41.2% sensitivity for AFB-positive and 31.7% for AFB-negative patients were achieved. Conclusion In conclusion, TB-QUICK exhibits rapidity and sensitivity for M.tb DNA detection with the superiority in smear-negative paucibacillary TB patients. The clinical application of TB-QUICK in TB diagnosis needs to be further validated in larger cohort.