Characteristics of rifampicin and isoniazid resistance genes in Mycobacterium tuberculosis in a hospital

Abstract:

ObjectiveTo understand the mutation characteristics of rifampicin resistance gene rpoB as well as isoniazid resistance genes katG and inhA of Mycobacterium tuberculosis(MTB) in a hospital, and provide scientific basis for the prevention and treatment of drugresistant tuberculosis.MethodsMTB strains were isolated from sputum specimens of 83 patients with tuberculosis, rifampicin and isoniazid resistance was detected by BD960 liquid culture method, DNA of MTB was extracted, complete genome of rpoB, katG and inhA were amplified by polymerase chain reaction, the amplified product was sequenced and analyzed.ResultsAmong 83 strains from specimens, 39 strains were resistant to rifampicin and 51 were resistant to isoniazid. The mutation rate of rpoB gene of rifampicinresistant strain was 97.44% (38/39), mutation rate of locus 531 and locus 526 were 60.53% (23/38) and 23.68%（9/38）respectively, combined mutation of multilocus appeared in 32 strains. The mutation rate of katG gene in isoniazidresistant strains was 98.04% (50/51), a total of 16 types of mutations were found, the majority of which were point mutations at katG 315, accounting for 70.00% (35/50), and one isolate was combined mutation of katG and inhA.ConclusionResistance of multidrugresistant(MDR) MTB is related to mutation in rpoB and katG genes, detection of MDR gene mutation in MTB can provide reference for early and rapid diagnosis of tuberculosis.