Novel mutations detected from drug resistant Mycobacterium tuberculosis isolated from North East of Thailand

Abstract

The emergence of drug-resistant tuberculosis is a major global public health threat. Thailand is one of the top 14 countries with high tuberculosis, tuberculosis co-infected with Human Immunodeficiency Virus (HIV) and multi-drug resistant tuberculosis rates. Immediate detection of drug-resistant tuberculosis is necessary to reduce mortality and morbidity by effectively providing treatment to ameliorate the formation of resistant strains. Limited data exist of mutation profiles in Northeastern Thailand. Here, 65 drug-resistant Mycobacterium tuberculosis isolates were used to detect mutations by polymerase chain reaction (PCR) and DNA sequencing. In the katG gene, mutations occurred in 47(79.7%) among 59 isoniazid resistant samples. For rpoB gene, 31 (96.9%) were observed as mutations in 32 rifampicin resistant isolates. Of 47 katG mutation samples, 45 (95.7%) had mutations in katG315 codon and 2 (4.3%) showed novel mutations at katG365 with amino acid substitution of CCG-CGG (Pro-Arg). Moreover, 18 (58.1%) mutations at rpoB531, 11 (35.5%) mutations at rpoB516, 10 (32.3%) mutations at rpoB526 and 1 (3.2%) mutation at rpoB533 were found between 31 rifampicin resistant samples. Common and novel mutations of the rpoB and katG genes in Northeastern Thailand were generated. DNA sequencing showed high accuracy, while conventional polymerase chain reaction could be applied as an initial marker for screening rifampicin and isoniazid drug-resistant Mycobacterium tuberculosis in Northeastern Thailand. Mutations reported here should be considered when developing new molecular diagnostic methods for implementation in Northeastern Thailand.

Mutations and insights into the molecular mechanisms of resistance of Mycobacterium tuberculosis to first-line

“…Since 2017, several new single nucleotide polymorphisms (SNP) for KatG which are associated with INH resistance have been isolated, and some are summarized herein (Table S1) (Figure 4A). Thwe et al (2021) performed a study using PCR and DNA sequencing in 65 drug-resistant Mtb isolates, revealed a number of new mutations on katG (Thwe et al, 2021). A novel single nucleotide polymorphism (SNP) that causes INH resistance was identified in two of the studied isolates.…”

“…A novel single nucleotide polymorphism (SNP) that causes INH resistance was identified in two of the studied isolates. This mutation is the substitution of proline for arginine at position 365 (P365R) (Thwe et al, 2021). This mutation was not characterized, however, although the residue P365 is more than 16Å away from the KatG active site, it was assumed to cause INH resistance.…”

Computer-aided diagnosis using embedded ensemble deep learning for multiclass drug-resistant tuberculosis classification

“…Research in Thailand has primarily focused on understanding drug resistance, including specific mutations in genes associated with resistance ( 7 ). Recent studies have identified novel mutations in drug-resistant TB strains across different regions of Thailand ( 8 ). Additionally, drug-resistant TB has been observed among Thai children ( 5 ).…”