Genotype mtbdrsl line probe assay

Two sputum samples from patients with presumptive pulmonary tuberculosis were collected. The sputa of patients with rifampicin resistance tuberculosis detected by GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) were further analysed for second-line drug resistance using the Genotype MTBDRsl/Line probe assay (Hain Life Science GmbH, Nehren, Germany). The GeneXpert MTB/RIF and Genotype MTBDRsl/Line probe assay tests were carried out according to the manufacturer’s instructions [13 , 14 ]. The line probe assay is a deoxyribonucleic acid (DNA) strip-based test determining Mycobacterium tuberculosis drug-resistant strains. It identifies resistance due to mutations in gyrA (from codon 85–96) and gyrB (from codon 536–541) [2 (link)] genes for fluoroquinolone (levofloxacin or moxifloxacin), the rrs gene’s (nucleic acid position 1401, 1402 and 1484) and the eis gene’s promoter region (from − 37 to − 2 nucleotides upstream) for detection of resistance to the second-line injectable anti-TB drugs (kanamycin, amikacin or capreomycin) used during the earlier years of the study period. Mutations are detected by either the binding of amplicons to probes targeting the most commonly occurring mutations (MUT probes); or by the lack of hybridisation (i.e. lack of binding) of the amplicons to the corresponding WT probes [13 ].