Developing a fast, inexpensive, and specific test that reflects the mutations present in
Mycobacterium tuberculosis
isolates
according to geographic region is the main challenge for drug-resistant tuberculosis (TB) control. The objective of this study
was to develop a molecular platform to make a rapid diagnosis of multidrug-resistant (MDR) and extensively drug-resistant
TB based on single nucleotide polymorphism (SNP) mutations present in the
rpoB,
katG,
inhA,
ahpC, and
gyrA genes
from Colombian
M. tuberculosis isolates. The amplification and sequencing of each target gene was performed. Capture
oligonucleotides, which were tested before being used with isolates to assess the performance, were designed for wild type
and mutated codons, and the platform was standardised based on the reverse hybridisation principle. This method was
tested on DNA samples extracted from clinical isolates from 160 Colombian patients who were previously phenotypically
and genotypically characterised as having susceptible or MDR
M. tuberculosis. For our method, the kappa index of the
sequencing results was 0,966, 0,825, 0,766, 0,740, and 0,625 for
rpoB,
katG,
inhA,
ahpC, and
gyrA, respectively. Sensitivity
and specificity were ranked between 90-100% compared with those of phenotypic drug susceptibility testing. Our assay
helps to pave the way for implementation locally and for specifically adapted methods that can simultaneously detect drug
resistance mutations to first and second-line drugs within a few hours.
