Rapid detection of rpoB and katG genes from the sputum of multidrug-resistant Mycobacterium tuberculosis by polymerase chain reaction (PCR)- direct sequencing analysis

Abstract

Rapid diagnosis of multidrug- resistant Mycobacterium tuberculosis (MDR-TB) plays a role in guiding
standardized treatment regimen. Traditional drug susceptibility (DST) testing takes about six to eight
weeks. Therefore, the aim of the present study is to characterize the mutations in rpoB and katG genes
from the sputum specimens of MDR-TB by using polymerase chain reaction (PCR)-direct sequencing
analysis and to diagnose the MDR-TB as soon as earlier. The sensitivity and specificity of this
molecular DST would be assessed further. Rpob and katG genes were detected directly from the clinical
sputum specimens of inpatients with MDR-TB by PCR-direct sequencing. The sensitivity, specificity of
rpoB and katG gene for 48 specimens was as follows: 95.8, 100% and 93.75, 97.9%, respectively. Our
study demonstrated that PCR-direct sequencing analysis was a rapid, sensitive and specific molecular
approach for the mutation detection of rpoB and katG genes that are associated with multidrugresistance clinical sputum specimens within 48 h of receipt, which is more rapid than drug
susceptibility testing after the bacillus culture.