Molecular Characterization of Multidrug-Resistant Mycobacterium tuberculosis Isolates from China

Abstract

eTo investigate the molecular characterization of multidrug-resistant tuberculosis (MDR-TB) isolates from China and the association of specific mutations conferring drug resistance with strains of different genotypes, we performed spoligotyping and sequenced nine loci (katG, inhA, the oxyR-ahpC intergenic region, rpoB, tlyA, eis, rrs, gyrA, and gyrB) for 128 MDR-TB isolates. Our results showed that 108 isolates (84.4%) were Beijing family strains, 64 (59.3%) of which were identified as modern Beijing strains. Compared with the phenotypic data, the sensitivity and specificity of DNA sequencing were 89.1% and 100.0%, respectively, for isoniazid (INH) resistance, 93.8% and 100.0% for rifampin (RIF) resistance, 60.0% and 99.4% for capreomycin (CAP) resistance, 84.6% and 99.4% for kanamycin (KAN) resistance, and 90.0% and 100.0% for ofloxacin (OFX) resistance. The most prevalent mutations among the MDR-TB isolates were katG315, inhA15, rpoB531, -526, and -516, rrs1401, eis-10, and gyrA94, -90, and -91. Furthermore, there was no association between specific resistance-conferring mutations and the strain genotype. These findings will be helpful for the establishment of rapid molecular diagnostic methods to be implemented in China.

Molecular characterisation of extensively drug-resistant Mycobacterium tuberculosis isolates in China

“…Accordingly, 63.8% and 32.8% of XDR-TB isolates in the current study harboured mutations in katG and inhA, respectively. The combination of mutations in katG and inhA promoter region could detect 81.0% of INH resistance among XDR-TB isolates, which is similar to previous data from China [8,12]. In addition, four XDR-TB isolates (6.9%) carried single mutations only in the A(-8)G of oxyR-ahpC AGC → AAC Ser315Asn 4 (6.9) [4,7,8,[12][13][14][15].…”

Prevalence and Molecular Characteristics of Drug-Resistant Mycobacterium tuberculosis in Hunan, China

“…DNA sequencing of the hot spot regions in genetic loci demonstrated that the frequency of mutations occurring among INHresistant isolates was 78.7%, similar to the results reported in Jiangxi (19) but lower than the data from Fujian and Shanghai, China. For the RIF-resistant isolates in China, substantial proportions (90.2% to 97.2%) of mutations within the rpoB gene were observed (19)(20)(21)(22)(23)(24)(25). Our results showed that 87.0% of the RIF-resistant isolates carried mutations in the rpoB gene.…”

Detection of multidrug-resistant Mycobacterium tuberculosis strains isolated in Brazil using a multimarker genetic assay for katG and rpoB genes

“…Also, the frequency of 62.8% for S531L (rpoB) found in this work was consistent with other studies, considering that published rates range between 40.1% and 82.4%. [31][32][33][34] In the same way, H526D (rpoB) polymorphism, with a found frequency of 7% in this work amply oscillates worldwide, with values ranging from 5.9% to 40%. 31,34 Therefore, great frequency variations are evident between countries, making it necessary to study locally the prevalence of the canonical mutations for each geographical region in order to figure out which polymorphisms have the best predictive accuracy.…”

“…[31][32][33][34] In the same way, H526D (rpoB) polymorphism, with a found frequency of 7% in this work amply oscillates worldwide, with values ranging from 5.9% to 40%. 31,34 Therefore, great frequency variations are evident between countries, making it necessary to study locally the prevalence of the canonical mutations for each geographical region in order to figure out which polymorphisms have the best predictive accuracy. As early diagnosis is the best strategy to control MDRTB, several molecular methods to detect drug resistance in M. tuberculosis are currently widely employed.…”