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

AbstractThe emergence of drug-resistant tuberculosis is a major global public health threat. Thailand is one of the top 14 countries with high tuberculosis 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-resistantMycobacterium tuberculosis isolates were used to detect mutations by polymerase chain reaction (PCR) and DNA sequencing. In thekatG gene, mutations were occurred in 47 (79.7%) among 59 isoniazid resistant samples. ForrpoB gene, 31 (96.9%) were observed as mutations in 32 rifampicin resistant isolates. Of 47katG mutation samples, 45 (95.7%) had mutations inkatG315 codon and 2 (4.3%) showed novel mutations atkatG365 with amino acid substitution of CCG-CGG (Pro-Arg). Moreover, out of 31rpoB mutation isolates, the codon positionsrpoB516,rpoB526,rpoB531 andrpoB533 were 3 (9.7%), 8 (25.8%), 11 (35.5%) and 1 (3.2%), respectively. Seven isolates of double point mutation were found [rpoB516, 526; 1 (3.2%) andrpoB516, 531; 6 (19.4%)]. In addition, 1 (3.2%) sample had triple point mutation at codon positionsrpoB516, 526 and 531. Common and novel mutation codons of therpoB andkatG genes were generated. Although DNA sequencing showed high accuracy, conventional PCR could be applied as an initial marker for screening drug-res...
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research