Abstract:

Objective To analyze the resistance of prothionamide (Pto) and sodium phenyl aminosalicylate (PAS) in patients with isoniazid (IHN)-resistant pulmonary tuberculosis (PTB), and the correlation of inhA genes and Pto resistance. Methods We retrospectively collected data of 849 PTB patients diagnosed as INH resistant by 960 liquid drug susceptibility test (DST) in Xi’an Chest Hospital from Jan 1, 2018 to Dec 31, 2020. The DST results of rifampicin, Pto, PAS, and mutation of katG and inhA gene were analyzed. The correlation of inhA and Pto resistance was examined with Cohen’s Kappa test. Results In 849 cases of INH resistant patients, 33 cases were resistant to Pto, the drug resistance rate was 3.89% (33/849). One hundred and one patients were resistant to PAS, the drug resistance rate was 11.90%. Among 518 patients with INH resistance related gene detected by real-time PCR fusion curve test, the mutation rate of katG and inhA gene were 73.75% (382/518) and 15.83% (82/518) respectively, the drug resistance rate of Pto was 3.86% (20/518). Among 82 patients with inhA gene mutation,the drug resistance rate of Pto was 8.54% (7/82), while the inhA mutation rate among Pto resistant patients was 35.00% (7/20), their consistency was poor (Kappa=0.080). Conclusion The resistance rate of Pto among INH resistant patients was low, while resistance rate of PAS was high. The consistency of Pto resistance and inhA mutation was poor.

Key words: Mycobacterium tuberculosis, Drug resistance,bacterial, Evaluation studies, Prothionamide, Aminosalicylic acid