Characterization of katG, inhA, rpoB and pncA in Mycobacterium tuberculosis isolates from MDR-TB risk patients in Thailand

  • Krairerk Suthum The Office of Disease Prevention and Control 5th Ratchaburi, Department of Disease Control, Ministry of Public Health, Ratchaburi Province, Thailand
  • Worada Samosornsuk Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathumthani Province, Thailand
  • Seksun Samosornsuk Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathumthani Province, Thailand
Keywords: multidrug-resistant tuberculosis, MDR-TB, mutation, DNA sequencing

Abstract

Introduction: Multidrug-resistant tuberculosis (MDR-TB) is commonly found in Thailand especially in the public health region 5, the Western region of Thailand. This study’s aim was to characterize katG, inhA, rpoB and pncA genes in Mycobacterium tuberculosis.

Methodology: One hundred strains of Mycobacterium tuberculosis (MTB) were isolated from sputum samples of MDR-TB risk patients in the laboratory of the Office of Disease Prevention and Control 5th Ratchaburi province, Thailand from January to December 2015. Drug susceptibility testing (DST) was performed using a BACTEC MGIT 960 system. Furthermore, the genes katG, inhA, rpoB and pncA were characterized by DNA sequencing.

Results: Of a total of 100 MTB samples which underwent drug susceptibility testing, 42% showed isoniazid (INH) and rifampicin (RIF) resistance, and a further 25% showed INH mono-resistance (25%). The most common gene mutations found using DNA sequencing were katG_Ser315Thr (70%), rpoB_Ser531leu (81%) and pncA_Ile31Thr (84%). The common mutation of pncA_Ile31Thr substitution was detected in 26 of 91 (29%) pyrazinamide (PZA) susceptible isolates.

Conclusion: Using DNA sequencing to screen for gene mutations conferring drug resistance may be feasible and use less time than using DST to detect resistance patterns.

Published
2020-03-31
How to Cite
1.
Suthum K, Samosornsuk W, Samosornsuk S (2020) Characterization of katG, inhA, rpoB and pncA in Mycobacterium tuberculosis isolates from MDR-TB risk patients in Thailand. J Infect Dev Ctries 14:268-276. doi: 10.3855/jidc.11974
Section
Original Articles