WGS to predict drug susceptibility against first-line anti-tuberculosis drugs

We investigated the reliability of WGS to predict drug susceptibility and analysed the discrepancies between WGS and phenotypic DST by MGIT against the first-line drugs rifampicin, isoniazid, ethambutol, and pyrazinamide. In total 1,136 MTBC isolates from 2016/2017 were included. The negative predictive value of WGS was > 99.3% for all four first-line antibiotics. The majority of discrepancies for isoniazid and ethambutol were explained by growth at the concentrations just below the critical concentrations, and for rifampicin by prolonged incubation, which are sometimes missed in the MGIT.