Related Experiment Video
Updated: Feb 16, 2026

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray
Published on: April 25, 2014
Extensively drug-resistant tuberculosis in Myanmar: burden and mutations causing second-line drug resistance
Setting:
Two tuberculosis (TB) reference laboratories in Myanmar.
Objectives:
To determine the proportion of extensively drug-resistant TB (XDR-TB) cases among multidrug-resistant TB (MDR-TB) cases and the mutations that cause resistance to second-line drugs in Myanmar.
Design:
This was a cross-sectional, retrospective study. Multidrug-resistant Mycobacterium tuberculosis isolates were collected during 2015-2016. Phenotypic drug susceptibility testing (DST) was performed and drug-resistant mutations identified by sequencing. Genotypes were determined to explain relationships between drug resistance patterns and genotypes.
Results:
Of 89 MDR-TB isolates, 12 were XDR-TB and 24 were pre-XDR-TB, with 21 resistant to fluoroquinolones (FQs) and 3 to second-line injectable agents (SLIDs). High rates of cross-resistance among second-line drugs were observed. Correlations between phenotypic and molecular DST against FQs and SLIDs were 91% in both cases. The most frequent mutation in FQ-resistant isolates was D94G (8/21) in gyrA and A1401G (11/15) in rrs in those resistant to SLIDs. The dominant genotype was the Beijing type (76/89).
Conclusion:
There were high proportions of XDR-TB and pre-XDR-TB among MDR-TB cases; cross-resistance among second-line drugs was high, with various types of genetic mutations. These data suggest that resistance to second-line anti-tuberculosis drugs should be monitored intensively, and molecular DST should be employed.
More Related Videos
Related Concept Videos
Resistivity
Resistance
Viral Mutations
Equivalent Resistance
Resistance and Conductance
Various factors impact the resistance of a conductor. Spiraling in stranded conductors increases their...
Rolling Resistance
For instance, imagine a hard cylinder rolling on a comparatively soft surface. The cylinder's weight compresses the surface beneath it. As the cylinder moves, the material in front of it slows down due to...

