A diagnostic test that uses isothermal amplification and lateral flow detection sdaA can detect tuberculosis in 60 min.

ABSTRACT

AIMS: Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is now the leading cause of death from infectious disease, thus rapid diagnostic and screening techniques for TB are urgently needed. METHODS AND RESULTS: Here, a detection of MTB using multiple cross displacement amplification coupling with nanoparticles-based lateral flow device (MCDA-LFD) was developed and validated, targeting the specific sdaA gene. The whole detection procedure, including rapid genomic DNA extraction (15 min), amplification (30 min) and result reporting (2 min), was completed within 50 min. No cross-reaction with non-mycobacteria and non-tuberculous mycobacteria (NTM) strains was observed. The sensitivity of sdaA-MCDA-LFD, Xpert MTB/RIF assay and culture results was 81·6, 48·3 and 37·9%, respectively, in TB patients. Among positive culture samples, the sensitivity of sdaA-MCDA-LFD and Xpert MTB/RIF assay was 93·9% (31/33) and 81·8% (27/33), respectively. Among culture-negative samples, the sensitivity of sdaA-MCDA-LFD and Xpert MTB/RIF assay was 74·1% (40/54) and 27·8% (15/54), respectively. The specificity of sdaA-MCDA-LFD and Xpert MTB/RIF was 95·4% (62/65) and 100% (65/65) in clinical samples from non-TB patients. CONCLUSION: The sdaA-MCDA-LFD assay was a rapid, simple, specific and sensitive TB diagnostic test. SIGNIFICANCE AND IMPACT OF THE STUDY The sdaA-MCDA-LFD assay holds promise for application as a useful point-of-care test to detect MTB, and will play an important role in controlling and preventing TB.