Fig 1.
Diagnostic workflow of the patients included in the study.
Table 1.
Performance of the GeneXpert for the diagnosis of TB: Sensitivity, Specificity of GeneXpert MTB/RIF in comparison with Composite Reference Standards.
Table 2.
Performance of Genexpert for detection of RIF resistance: sensitivity and specificity of the genexpert for detection of RIF resistance in comparison with gold standard phenotypic [MGIT 960, LC-DST] and genotypic [sequencing] results.
Fig 2.
GeneXpert Detection of mutations in rpoB RRDR region.
Results from twenty-five Rif resistant samples are shown. The results produced by each sample are indicated by a single vertical line on which the CT value of each of the five rpoB-specific molecular beacons [probes A to E] is plotted. Twenty-three samples were correctly identified as Rif resistant. Two samples [731GE, 919GE] were missed by GeneXpert but showed mutations in RRDR region on rpoB gene Sequencing [533CGG, 517AAG and 519CAC respectively] [Genbank Accession Numbers KP658669-658720]. Two strains with 531TTG mutation were detected owing to difference between the CT value being >4 and not due to loss of probe.
Table 3.
Samples with Discordant Results.
Table 4.
Correlation of Bacterial load [GeneXpert] with Drug susceptibility pattern [LC-DST].
Fig 3.
Forest plot showing Genexpert MTB/RIF sensitivity and specificity for tuberculosis detection against the composite reference standards, in different types of Extra-pulmonary samples when compared with other published studies.
The squares represent the sensitivity and specificity; the black line indicates the confidence interval. [42–46]