Predominance of the East-Asian Beijing genotype in a Mycobacterium tuberculosis drug-resistant population in Central Malaysia.

Objectives: Previous diversity studies on local Mycobacterium tuberculosis (MTB) isolates, with or without antibiotic resistance, showed predominance of Indo-Oceanic East African-Indian (EAI) strains. This study focused specifically on a drug-resistant MTB population from Central Malaysia and aimed to investigate the genotypes and resistance patterns involved.

Methods: Whole-genome sequencing was performed on 56 local MTB isolates with known rifampicin resistance or multidrug resistance towards 13 anti-TB agents. Analysis of each genome sequence was performed using the widely recognized online MTB genotyping platforms, TBProfiler and Mykrobe, to determine lineage and genotypic drug resistance profiles.

Results: Forty (71.4%) isolates were identified as East-Asian Beijing strains. Phenotypic to genotypic antibiotic resistance patterns differed in 33 isolates (58.9%), with one isolate showing extensive drug-resistance (XDR) previously not detected by conventional drug-susceptibility testing.

Conclusion: This drug resistance population study demonstrated predominance of the East-Asian Beijing strains and a newly detected extensively drug-resistant MTB (XDR-TB) isolate in Malaysia. Information regarding the association between lineage and drug-resistant TB in Malaysia is scarce, and more studies are needed to determine the significance of such association, if any, in our local settings.