Putative extensive and pre-extensive drug resistant-tuberculosis associated with unusual genotypes on the Thailand-Myanmar border

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Janisara Rudeeaneksin, Wiphat Klayut, Sopa Srisungngam, Supranee Bunchoo, Sarawut Toonkomdang, Thanee Wongchai, Nattagarn Chuenchom, Benjawan Phetsuksiri
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2021
• Subjects: Extensively drug-resistant tuberculosis; XDR-TB; Diagnosis; Genotypes; Thailand-Myanmar border; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Rif
• Online Access: https://doi.org/10.1590/s1678-9946202163085; https://doaj.org/article/5e49d2ea87924cd8b16c8c1e0e6630bd

ABSTRACT Extensive drug-resistant tuberculosis (XDR-TB) is highly life threatening and its diagnosis is usually difficult and time-consuming. Here we present the first two cases of XDR and pre-XDR-TB diagnosed in 2018 on the Thailand-Myanmar border, more specifically in Tak province. Rapid detection of XDR-TB was performed by loop-mediated isothermal amplification (LAMP), Xpert MTB/RIF, and line probe assays. Mutation analyses targeting rpoB, katG, inhA, gyrA and rrs genes showed an association with drug-resistant phenotypes, except for rifampicin resistance. Spoligotyping revealed uncommon Beijing and T2 genotypes and the analysis of M. tuberculosis interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) showed the presence of more polymorphisms. This report highlights the importance of the early detection of drug-resistant tuberculosis by molecular tests followed by phenotyping assays. Based on the up-to-date definition of XDR- and pre-XDR-TB, the susceptibility testing for bedaquiline and linezolid is required and the two reported cases may correspond to putative XDR-TB.