Comparison between phenotypic and whole-genome sequencing drug susceptibility testing in multidrug resistant Mycobacterium tuberculosis isolates from South Korea

초록

Background Whole genome sequencing (WGS) has been applied to solve the public concerns of tuberculosis (TB). TB is one of the serious infectious diseases in South Korea, reporting 49 new cases per 100,000 people and 629 multi-drug resistant (MDR) TB in 2020. We aimed to investigate the genetic differences between isolates using WGS combined with clinical data. Methods WGS using the Illumina HiSeq platform was per-formed for MDR-TB strains isolated from 80 TB patients treated in seven hospitals of southern metropolitan area, retrospectively. The WGS analysis was performed with bioinformatics platforms using TB profiler. Phylogenetic trees were created, and phenotypic susceptibilities test (pDST) were compared with molecular DST (mDST) of WGS. Results Among 80 MDR-TB strains including 18 pre-XDRTB, 44 patients were primary MDR-TB. Fifty-seven strains were from Native Koreans, 16 strains from Korean-Chinese,and 7 strains from Central Asians, among which some clusters were identified. For first line anti-TB drugs concordant with phenotypic DST for Rifampicin, Isoniazid, Pyrazinamide, Ethambutol were 100.0%, 100.0%%, 85.0% and 85.0% respectively. The sensitivity of mDST compared with pDST for rifampicin, isoniazid, pyrazinamide and ethambutol, fluoroquinolones were 100.0%, 100.0%, 84.0%, 92.0%, and 100.0%, respectively. The concordance rate for second line drugs varied from 75.0% to 99.0%. The sensitivity and specificity ranged from 47.0% to 100.0%, and from 76.0% to 99.0%, respectively. Conclusions The role of WGS for first line anti-TB drugs as well as fluoroquinolones are quite promising in South Korea, and further larger studies for second line drugs are needed.