Abstract: Objective To analyze the drug resistance of pulmonary tuberculosis patients in Nanjing during the past 5 years, and to provide clinical basis for the diagnosis and treatment of pulmonary tuberculosis. Method The clinical data of patients with positive sputum culture concurrent with bacterial species identification and drug susceptibility testing in Nanjing Second Hospital from January 2018 to December 2022 were collected, and their drug resistance trends and characteristics were analyzed. Result A total of 4824 clinical isolates were included, including: 3855(79.91%) strains of human Mycobacterium tuberculosis, 39(0.81%) Mycobacterium bovis strains and 930(19.28%) nontuberculous Mycobacterium strains. Among the 3855 strains of Mycobacterium tuberculosis, there were 1077 drug-resistant strains, and the overall drug resistance rate was 27.94%. Among them, 462(11.98%) strains were resistant to rifampicin, and 218(5.66%) strains were multidrug-resistant. 201(5.21%) strains were poly-resistant, and 41(1.06%) strains were extensively drug-resistant. Univariate analysis showed that age 30≤age<60 years and retreatment were risk factors for drug resistance. The overall drug resistance rate of tuberculosis patients in Nanjing area showed a slow rising trend in the preceding four years, reaching a peak of 31.21% in 2021,and decreasing to 25.56% in 2022. Rifampicin resistance rate fluctuated slightly, stabilizing at 11%-12% from 2018 to 2020, rising sharply to 16.56% in 2021, and decreasing to 10.31% in 2022. Among the nine anti-tuberculosis drugs tested, the sequence of drug resistance of Mycobacterium tuberculosis strains was: isoniazid (16.78%), streptomycin (15.80%), rifampicin (11.93%), levofloxacin (8.87%), ethambutol (4.88%), amikacin (1.79%), kanamycin（1.50%）, para aminosalicylic acid (1.45%) and capreomycin (1.32%). The sequence of drug resistance during 2018-2022 was similar, with the top five being isoniazid, streptomycin, rifampicin, levofloxacin and ethambutol, and the drug resistance rates of the second-line injection anti-tuberculosis drugs amikacin, capreomycin and kanamycin were all lower. Conclusion In the period of 2022, the prevention and control of tuberculosis in Nanjing area achieved certain results, and the overall drug resistance rate and rifampicin resistance rate decreased compared with the rate of 2018-2021. It is necessary to pay special attention to young men and patients with retreatment, and rationally select anti-tuberculosis drugs according to drug susceptibility results to reduce the spread of drug-resistant mycobacterium tuberculosis.

Key words: Mycobacterium tuberculosis, Nontuberculosis mycobacteria, Nanjing, Drug resistance, Prevalence