Table 3. Samples with Discordant Results.
| Patient ID | Mycobacterium tuberculosis Genotypic drug resistance detection | |||
|---|---|---|---|---|
| 0.5μg/ml | 1 μg/ml | Rpo B Sequencing result [RRDR] | GeneXpert result | |
| 731 [SPUTUM] | RESISTANT | RESISTANT | CTG533CGG | MTB detected, Rifampicin sensitive. |
| 1014 [SPUTUM] | RESISTANT | RESISTANT | NO MUTATION | MTB detected, Rifampicin sensitive. |
| 30B[LYMPH NODE ASPIRATE] | RESISTANT | RESISTANT | NO MUTATION | MTB detected, Rifampicin sensitive. |
| 919GE [PUS] | RESISTANT | RESISTANT | CAG517AAG AAC519CAC | MTB detected, Rifampicin sensitive. |
Summary of MICs determined by LC-DST in the automated MGIT 960 system, GeneXpert results, rpoB gene Sequencing for five M. tuberculosis isolates. While four GeneXpert results were discordant with LC-DST, two of the isolates did not show any mutation in the rpoB RRDR region, indicating resistance due to sites outside RRDR. [Genbank Accession Numbers KP658669-658720]
Total resistant: 27
Discordant results between Genexpert & LC-DST: 4
Discordant results between Genexpert & sequencing: 2 [1 pulmonary,1 extra-pulmonary]
Discordance between the two gold standards: 2 [1 pulmonary,1 extra-pulmonary][due to restricting genotypic evaluation to RRDR]