The
untested empirical medications exacerbated the development
of multidrug-resistant Mycobacterium tuberculosis (MDR-TB). Here, we develop a rapid and specific method based on
loop-mediated isothermal amplification and duplex-specific nuclease
for distinguishing rifampicin-resistant M. tuberculosis. Three probes were designed for the codons 516, 526, and 531 on
the RNA polymerase β-subunit (rpoB) gene. These three sites
accounted for more than 90% of the total mutations of the ropB gene
in the rifampicin-resistant strain. The approach can perform simultaneous
and sensitive detection of three mutant sites with the actual detection
limit as 10 aM of DNA and 62.5 cfu·mL–1 of
bacteria in 67 min under isothermal conditions. Moreover, the positive
mode of the approach for MDR-TB can not only deal with the randomness
and diversity of mutations but also provide an easier way for medical
staff to read the results. Therefore, it is a particularly valuable
method to handle major and urgent MDR-TB diagnostics.