The objectives of the study were to compare the performance of line probe assay (GenoType MTBDRplus) with solid culture method for an early diagnosis of multidrug resistant tuberculosis (MDR-TB), and to study the mutation patterns associated with rpoB, katG and inhA genes at a tertiary care centre in north India.
Data from the Western Cape revealed that significantly more XDR-TB isolates showed mutations in the inhA promoter than in katG (85.5% vs. 60.9%, P < 0.01), while the respective proportions were equal for INH-resistant non-MDR-TB isolates (∼30%).
Sequencing analysis was performed of the rpoB rifampicin resistance-determining region and the katG gene, the oxyR-ahpC intergenic region, and the inhA promoter region in 259 MDR M. tuberculosis isolates, in 51 isoniazid-resistant isolates, and in 13 rifampicin-resistant isolates.
In brief, the results showed that the REBA MTB-MDR assay efficiently recognized nucleotide changes in the oxyR-ahpC intergenic region as well as those in rpoB, katG and the inhA promoter region with higher sensitivity, resulting in an 81.0 % detection rate for isoniazid resistance.