<p>Prevalence, risk and genetic characteristics of drug-resistant tuberculosis in a tertiary care tuberculosis hospital in China</p>

Abstract

Objectives To explore the prevalence, risk and genetic characteristics of drug-resistant tuberculosis (TB) from a tertiary care TB hospital in China. Patients and methods We carried out a retrospective study including isolates from 189 patients with pulmonary TB at Fuzhou Pulmonary Hospital. All isolates from these patients were subjected to drug susceptibility testing and genotyping. For drug-resistant isolates, DNA sequencing was used to investigate mutations in 12 loci, including katG , inhA , oxyR–ahpC , rpoB , rpsL , rrs 1 (nucleotides 388–1084 of rrs), embB , tlyA , eis , rrs 2 (nucleotides 1158–1674 of rrs), gyrA and gyrB . Results Among 189 isolates, 28.6% were resistant to at least one of the seven anti-TB drugs, including isoniazid (INH), rifampin (RIF), streptomycin (STR), ethambutol (EMB), capreomycin (CAP), kanzmycin (KAN) and ofloxacin (OFX). The proportion of multidrug-resistant TB and extensively drug-resistant TB isolates was 9.5% and 1.1%, respectively. Patients in rural areas as well as previously treated patients showed a significantly increased risk of developing drug resistance. In addition, among these isolates, 111 (58.7%) were Beijing genotype strains, 84 (75.7%) of which belonged to modern Beijing sublineage. There was no association between genotype and drug resistance. The most common mutations were katG 315, rpo B 531 rpsL 43, embB 306, rrs 1401 and gyrA 94. Conclusion These findings provided additional information of drug-resistant TB in China. Previously treated patients and patients in rural areas should receive greater attention owing to their higher risk of developing drug resistance.

Prevalence and Molecular Characteristics Based on Whole Genome Sequencing of Mycobacterium tuberculosis Resistant to Four Anti-Tuberculosis Drugs from Southern Xinjiang, China

“… 34 We also observed that the Beijing genotype exhibited a significantly higher risk for developing MDR-TB compared to non-Beijing genotype, suggesting that Beijing genotype be responsible for the spread and emergence of MDR-TB in this region. As reported in previous studies, 35 , 36 retreated patients in this study were also found with high risk for developing MDR-TB, stressing the importance of early diagnosis, and timely, long-term and standardized medication, especially among patients treated within the hospital system in this region.…”

“… 6 , 42 There was no isolate carried rrs mutation combined with rpsL mutation in this study, suggesting that mutations in rrs and rpsL genes were mutually exclusive. Mutations in rrs and rpsL genes accounted for 68.6% STR resistance, higher than the data from the tertiary care tuberculosis hospital in China 35 and Mexico, 43 but lower than that from other regions, 44 , 45 indicating that there were regional differences in the mutations associated with STR resistance and additional resistance mechanisms correlated with STR resistance, such as gidB which was reported to contribute 2.4% to 37.5% STR resistance. 42 , 44 , 46–48 …”