Xpert MTB/RIF test for rapid diagnosis of Mycobacterium tuberculosis and simultaneous detection of multidrug-resistant tuberculous bacillus

Tuberculosis (TB) is endemic in China with high prevalence of multiple-drug resistant tuberculous bacilli (MDR-TB). The incidence of new cases of TB reaches 1,300 thousand annually. Among them, 5.7 percent are MDR-TB. Staining for acid-fast bacilli in sputum and clinicoradiological examination have been the main diagnostic tools for TB, particularly pulmonary TB. However, the positive rate of sputum Ziehl-Neelsen stain for sputum is disappointedly low, merely 28% in newly-diagnosed TB. Moreover, the radiological manifestations of the patients suspected of TB are often non-specific. All these facts call for a simple, accurate and rapid diagnostic method to overcome this bottleneck, which hinders the success of satisfactory TB control in China. Employing both hemi-nested RT-PCR and beacon technology with fluorescent probes, the MTB/RIF diagnostic assay specifically amplifies, thus helps detect the rpoB gene, which is unique to Mycobacterium tuberculosis and also a biomolecular-marker of rifampin resistance. As