Molecular Identification of Mycobacterium tuberculosis and Analysis of Its Resistance to Rifampin in Sputa From Tuberculosis Suspected Patients

An accurate identification of different species of Mycobacterium provides to allow
appropriate treatment for Mycobacterium tuberculosis infection. Beside that, drug
resistance of M. tuberculosis strains to rifampin is not clearly understood in
contributing to the spread of tuberculosis in Indonesia. To assess the molecular
mechanism of rifampin resistance, a number of clinical specimens of
M. tuberculosis were analyzed their molecular nature of a part of the rpoB gene
using polymerase chain reaction-single strand conformation polymorphism
(PCR-SSCP) methods. DNA’s extracted from sputum samples were amplified and
32P-labeled by PCR with the specific primers and the product was analyzed their
mutation conferring resistance by MDE gel electrophoresis. Of the 70 specimens
tested, 57 specimens were positive for M. tuberculosis organism only, three
specimens contained a mixture of M. tuberculosis and non tuberculosis
mycobacteria (NTM), and 10 specimens were negative approved by Duplex PCR.
Of these sixty DNA positive samples (thus the sensitivity of PCR was 85.71%),
5 (8.3%) of them suspected to contain mutations in rpoB which were associated
with rifampin resistance. Even though the frequency of mutation was low, the
results from our study clearly indicate that the molecular mechanism of rifampin
resistance in M. tuberculosis isolates from Indonesia involves alterations in the
rpoB gene. Molecular diagnosis by PCR which is fast and easy to perform is useful
for early and rapid detection of TB in sputum specimen.