To evaluate the value of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) in the detection of drug resistance of Mycobacterium tuberculosis in re-treated patients.

MALDI-TOF MS was used to detect the resistance of 202 cases of retreatment pulmonary tuberculosis infection strains to isoniazid (INH), rifampin (RFP), ethambutol (EMB), streptomycin (SM), ofloxacin (Ofx), moxifloxacin (Mfx), amikacin (Am), Kanamycin (Km) and capreomycin (Cm), and the results were compared with those of BACTEC 960 liquid culture detection to compare the coincidence rate of the two methods.

MALDI-TOF MS detected 60 copies of Mtb gene mutation, and drug-resistant gene mutation strains accounted for 34.68% (60/173) of positive strains. Rifampicin-related rpoB gene mutations accounted for 86.67% (52/60), isoniazid-related katG + inhA gene mutations accounted for 80.00% (48/60) and inhA-15 gene mutations accounted for 8.33% (5/60), streptomycin-related rpsL gene mutations accounted for 28.33% (17/60), ethambutol-related embB gene mutations accounted for 45.00% (27/60), quinolone-related gyrA basic mutation accounted for 26.67% (16/60), ethyl/propylthiamine-related embB gene mutation accounted for 36.67% (22/60) and inhA-15 gene mutation accounted for 10.00% (6/60), aminoglycoside-related rrs gene mutation accounted for 26.67% (16/60), clofazimine Fazimine, bedaquiline related Rv0678 193 gene mutations accounted for 3.33% (2/60), pyrazinamide, p-aminosalicylate, linezolid were not seen mutated genes. Multi-gene mutant strains accounted for 63.33% (38/60) of drug-resistant strains.

MALDI-TOF MS assay has good agreement with BACTEC960 liquid culture drug sensitivity test, which can be a rapid and effective method to screen for drug resistance of Mycobacterium tuberculosis, and has some clinical application value in patients with relapse tuberculosis.