Abstract:

Objective To compare Genechip and the proportion method drug susceptibility test in detecting Mycobacterium tuberculosis resistance to rifampin and isoniazid.Methods A total of 598 sputum specimens of sputum smear-positive pulmonary tuberculosis inpatient cases from the Affiliated Hospital of Hainan Medical College between September 2013 and December 2016. Finally, 484 patients with the results of both traditional drug susceptibility test and Genechip were included. Genechip was used to detect the mutations and frequencies of rpoB, katG and inhA. The proportion method drug susceptibility test was used as the gold standard to evaluate the overall concordance.Results Compared with the proportion method drug susceptibility test, the coincidence rate of Mycobacterium tuberculosis resistance to rifampin and isoniazid detected by Genechip was 93.8% (454/484) and 89.0% (431/484), respectively, and that to multi-drug resistance was 95.5% (462/484). The rpoB mutations were detected in 118 strains, of which 56.8% (67/118) carried mutations at codon 531, 19.5% (23/118) at codon 526, 12.7% (15/118) at codon 516. Of all the 97 strains with katG and inhA mutations, the predominant mutation site of katG was codon 315 with the mutation rate of 82.5% (80/97), and 14.4% (14/97) carried mutations at inhA-15 (C→T).Conclusion The results of Genechip method were highly consistent with that of proportion method drug susceptibility test, and Genechip was a fast and effective method for screening for rifampin and isoniazid against Mycobacterium tuberculosis.

Key words: Mycobacterium tuberculosis, Rifampin, Isoniazid, Microbial sensitivity tests, Oligonucletide array sequence analysis, Evaluation studies