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Saini A, Dadwal R, Yadav R, Kanaujia R, Aggarwal AN, Arora A, Sethi S. Whole genome sequencing for the prediction of resistant tuberculosis strains from northern India. Indian J Med Microbiol 2024; 48:100537. [PMID: 38350525 DOI: 10.1016/j.ijmmb.2024.100537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/07/2023] [Accepted: 02/09/2024] [Indexed: 02/15/2024]
Abstract
PURPOSE Tuberculosis is an important public health problem among infectious diseases. The problem becomes more concerning with the emergence of MDR-TB and pre-XDR-TB. Whole genome sequencing (WGS) detection of resistance has recently gained popularity as it has advantages over other commercial techniques. METHODS We performed in-house WGS followed by detailed analysis by an in-house pipeline to identify the resistance markers. This was accompanied by Phenotypic DST, and Sanger sequencing on all the 12 XDR, 06 pre-XDR, and 06 susceptible M. tb isolates. These results were collated with online M. tb WGS pipelines (TB profiler, PhyResSE, Mykrobe predictor) for comparative analysis. RESULTS Following our in-house analysis, we observed 64 non-synonymous SNPs, fifteen synonymous SNPs, and five INDELs in 25 drug resistance-associated genes/intergenic regions (IGRs) in M. tb isolates. Sensitivity for detecting XDR is 33%, 58%, 83%, and 83%, respectively, using Mykrobe predictor, PhyResSE, TB-profiler, and in-house pipeline for WGS analysis, respectively. TB-profiler detected a rare mutation H70R in the gyrA gene in one pre-XDR isolate. Lineage 2.2.1 East-Asian (Beijing sublineage type) predominated (60%) in WGS data analysis of the XDR isolates. CONCLUSIONS Our findings suggest that in-house analysis of WGS data and TB-profiler sensitivity was better for the detection of second-line resistance as compared to other automated tested tools. Frequent upgradation of newer mutations associated with resistance needs to be updated, as it potentiates tailored treatment for patients.
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Affiliation(s)
| | | | | | | | | | - Amit Arora
- Dept. of Medical Microbiology, PGIMER, India.
| | - Sunil Sethi
- Dept. of Medical Microbiology, PGIMER, India.
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Avhad T, Subith S, Shrivastava V, Zafar S, Chaudhary A. Multilevel Pre-extensively Drug-resistant Tubercular Spondylodiscitis: Underdiagnosed or Overlooked? A Case Report. J Orthop Case Rep 2024; 14:178-181. [PMID: 38420252 PMCID: PMC10898690 DOI: 10.13107/jocr.2024.v14.i02.4262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 12/18/2023] [Indexed: 03/02/2024] Open
Abstract
Introduction Pre-extensively drug-resistant tuberculosis (TB) is characterized by resistance to either a fluoroquinolone (FQ) or a second-line injectable but not both. The urgent need for prompt diagnosis and targeted treatment is emphasized. This report aims to spotlight a case of spinal TB with insufficient assessment, resulting in delayed definitive treatment and an oversight contributing to heightened morbidity. Case Report An 18-year-old female who was initially diagnosed to have multidrug-resistant TB leading to a 2-year treatment which eventually resulted in multifocal involvement of the spine revealing TB relapse with FQ resistance, categorized as pre-extensively drug-resistant TB. Treatment was shifted to newer drugs, addressing challenges like bilateral psoas abscess, which lead to clinical improvement, allowing the patient to make a good recovery. Conclusion This case report emphasizes the significance of conducting culture and drug sensitivity testing in patients with tubercular spondylodiscitis. The aim is to prevent misdiagnosis and ensure informed decisions regarding definitive medical treatment or surgical management when necessary.
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Affiliation(s)
- Tanmay Avhad
- Department of Orthopaedics, B.Y.L Nair Charitable Hospital, Mumbai, Maharashtra, India
| | - S Subith
- Department of Orthopaedics, B.Y.L Nair Charitable Hospital, Mumbai, Maharashtra, India
| | - Vanksha Shrivastava
- Department of Orthopaedics, B.Y.L Nair Charitable Hospital, Mumbai, Maharashtra, India
| | - Syed Zafar
- Department of Orthopaedics, B.Y.L Nair Charitable Hospital, Mumbai, Maharashtra, India
| | - Arif Chaudhary
- Department of Orthopaedics, B.Y.L Nair Charitable Hospital, Mumbai, Maharashtra, India
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Barilar I, Battaglia S, Borroni E, Brandao AP, Brankin A, Cabibbe AM, Carter J, Chetty D, Cirillo DM, Claxton P, Clifton DA, Cohen T, Coronel J, Crook DW, Dreyer V, Earle SG, Escuyer V, Ferrazoli L, Fowler PW, Gao GF, Gardy J, Gharbia S, Ghisi KT, Ghodousi A, Gibertoni Cruz AL, Grandjean L, Grazian C, Groenheit R, Guthrie JL, He W, Hoffmann H, Hoosdally SJ, Hunt M, Iqbal Z, Ismail NA, Jarrett L, Joseph L, Jou R, Kambli P, Khot R, Knaggs J, Koch A, Kohlerschmidt D, Kouchaki S, Lachapelle AS, Lalvani A, Lapierre SG, Laurenson IF, Letcher B, Lin WH, Liu C, Liu D, Malone KM, Mandal A, Mansjö M, Calisto Matias DVL, Meintjes G, de Freitas Mendes F, Merker M, Mihalic M, Millard J, Miotto P, Mistry N, Moore D, Musser KA, Ngcamu D, Nhung HN, Niemann S, Nilgiriwala KS, Nimmo C, O’Donnell M, Okozi N, Oliveira RS, Omar SV, Paton N, Peto TEA, Pinhata JMW, Plesnik S, Puyen ZM, Rabodoarivelo MS, Rakotosamimanana N, Rancoita PMV, Rathod P, Robinson ER, Rodger G, Rodrigues C, Rodwell TC, Roohi A, Santos-Lazaro D, Shah S, Smith G, Kohl TA, Solano W, Spitaleri A, Steyn AJC, Supply P, Surve U, Tahseen S, Thuong NTT, Thwaites G, Todt K, Trovato A, Utpatel C, Van Rie A, Vijay S, Walker AS, Walker TM, Warren R, Werngren J, Wijkander M, Wilkinson RJ, Wilson DJ, Wintringer P, Xiao YX, Yang Y, Yanlin Z, Yao SY, Zhu B. Quantitative measurement of antibiotic resistance in Mycobacterium tuberculosis reveals genetic determinants of resistance and susceptibility in a target gene approach. Nat Commun 2024; 15:488. [PMID: 38216576 PMCID: PMC10786857 DOI: 10.1038/s41467-023-44325-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 12/08/2023] [Indexed: 01/14/2024] Open
Abstract
The World Health Organization has a goal of universal drug susceptibility testing for patients with tuberculosis. However, molecular diagnostics to date have focused largely on first-line drugs and predicting susceptibilities in a binary manner (classifying strains as either susceptible or resistant). Here, we used a multivariable linear mixed model alongside whole genome sequencing and a quantitative microtiter plate assay to relate genomic mutations to minimum inhibitory concentration (MIC) in 15,211 Mycobacterium tuberculosis clinical isolates from 23 countries across five continents. We identified 492 unique MIC-elevating variants across 13 drugs, as well as 91 mutations likely linked to hypersensitivity. Our results advance genetics-based diagnostics for tuberculosis and serve as a curated training/testing dataset for development of drug resistance prediction algorithms.
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Carter J. Quantitative measurement of antibiotic resistance in Mycobacterium tuberculosis reveals genetic determinants of resistance and susceptibility in a target gene approach. RESEARCH SQUARE 2023:rs.3.rs-3378915. [PMID: 37886522 PMCID: PMC10602118 DOI: 10.21203/rs.3.rs-3378915/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The World Health Organization has a goal of universal drug susceptibility testing for patients with tuberculosis; however, molecular diagnostics to date have focused largely on first-line drugs and predicting binary susceptibilities. We used a multivariable linear mixed model alongside whole genome sequencing and a quantitative microtiter plate assay to relate genomic mutations to minimum inhibitory concentration in 15,211 Mycobacterium tuberculosis patient isolates from 23 countries across five continents. This identified 492 unique MIC-elevating variants across thirteen drugs, as well as 91 mutations likely linked to hypersensitivity. Our results advance genetics-based diagnostics for tuberculosis and serve as a curated training/testing dataset for development of drug resistance prediction algorithms.
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An Q, Lin R, Yang Q, Wang C, Wang D. Evaluation of genetic mutations associated with phenotypic resistance to fluoroquinolones, bedaquiline, and linezolid in clinical Mycobacterium tuberculosis: A systematic review and meta-analysis. J Glob Antimicrob Resist 2023; 34:214-226. [PMID: 37172764 DOI: 10.1016/j.jgar.2023.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/26/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023] Open
Abstract
OBJECTIVES The aim of the study was to update the classification of drugs used in multidrug-resistant tuberculosis (MDR-TB) regimens. Group A drugs (fluoroquinolones, bedaquiline (BDQ), and linezolid (LZD)) are crucial drugs for the control of MDR-TB. Molecular drug resistance assays could facilitate the effective use of Group A drugs. METHODS We summarised the evidence implicating specific genetic mutations in resistance to Group A drugs. We searched PubMed, Embase, MEDLINE, and the Cochrane Library for studies published from the inception of each database until July 1, 2022. Using a random-effects model, we calculated the odds ratios and 95% confidence intervals as our measures of association. RESULTS A total of 5001 clinical isolates were included in 47 studies. Mutations in gyrA A90V, D94G, D94N, and D94Y were significantly associated with an increased risk of a levofloxacin (LFX)-resistant phenotype. In addition, mutations in gyrA G88C, A90V, D94G, D94H, D94N, and D94Y were significantly associated with an increased risk of a moxifloxacin (MFX)-resistant phenotype. In only one study, the majority of gene loci (n = 126, 90.65%) in BDQ-resistant isolates were observed to have unique mutations in atpE, Rv0678, mmpL5, pepQ, and Rv1979c. The most common mutations occurred at four sites in the rrl gene (g2061t, g2270c, g2270t, and g2814t) and at one site in rplC (C154R) in LZD-resistant isolates. Our meta-analysis demonstrated that there were no mutations associated with BDQ- or LZD-resistant phenotypes. CONCLUSION The mutations detected by rapid molecular assay were correlated with phenotypic resistance to LFX and MFX. The absence of mutation-phenotype associations for BDQ and LZD hindered the development of a rapid molecular assay.
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Affiliation(s)
- Qi An
- Scientific Research and Teaching Department, Public Health Clinical Center of Chengdu, Chengdu, Sichuan, China
| | - Rui Lin
- Scientific Research and Teaching Department, Public Health Clinical Center of Chengdu, Chengdu, Sichuan, China
| | - Qing Yang
- Scientific Research and Teaching Department, Public Health Clinical Center of Chengdu, Chengdu, Sichuan, China
| | - Chuan Wang
- Scientific Research and Teaching Department, Public Health Clinical Center of Chengdu, Chengdu, Sichuan, China.
| | - Dongmei Wang
- Scientific Research and Teaching Department, Public Health Clinical Center of Chengdu, Chengdu, Sichuan, China.
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Genome-wide association studies of global Mycobacterium tuberculosis resistance to 13 antimicrobials in 10,228 genomes identify new resistance mechanisms. PLoS Biol 2022; 20:e3001755. [PMID: 35944070 PMCID: PMC9363015 DOI: 10.1371/journal.pbio.3001755] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 07/12/2022] [Indexed: 11/29/2022] Open
Abstract
The emergence of drug-resistant tuberculosis is a major global public health concern that threatens the ability to control the disease. Whole-genome sequencing as a tool to rapidly diagnose resistant infections can transform patient treatment and clinical practice. While resistance mechanisms are well understood for some drugs, there are likely many mechanisms yet to be uncovered, particularly for new and repurposed drugs. We sequenced 10,228 Mycobacterium tuberculosis (MTB) isolates worldwide and determined the minimum inhibitory concentration (MIC) on a grid of 2-fold concentration dilutions for 13 antimicrobials using quantitative microtiter plate assays. We performed oligopeptide- and oligonucleotide-based genome-wide association studies using linear mixed models to discover resistance-conferring mechanisms not currently catalogued. Use of MIC over binary resistance phenotypes increased sample heritability for the new and repurposed drugs by 26% to 37%, increasing our ability to detect novel associations. For all drugs, we discovered uncatalogued variants associated with MIC, including in the Rv1218c promoter binding site of the transcriptional repressor Rv1219c (isoniazid), upstream of the vapBC20 operon that cleaves 23S rRNA (linezolid) and in the region encoding an α-helix lining the active site of Cyp142 (clofazimine, all p < 10-7.7). We observed that artefactual signals of cross-resistance could be unravelled based on the relative effect size on MIC. Our study demonstrates the ability of very large-scale studies to substantially improve our knowledge of genetic variants associated with antimicrobial resistance in M. tuberculosis.
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Pakamwong B, Thongdee P, Kamsri B, Phusi N, Kamsri P, Punkvang A, Ketrat S, Saparpakorn P, Hannongbua S, Ariyachaokun K, Suttisintong K, Sureram S, Kittakoop P, Hongmanee P, Santanirand P, Spencer J, Mulholland AJ, Pungpo P. Identification of Potent DNA Gyrase Inhibitors Active against Mycobacterium tuberculosis. J Chem Inf Model 2022; 62:1680-1690. [PMID: 35347987 DOI: 10.1021/acs.jcim.1c01390] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mycobacterium tuberculosis DNA gyrase manipulates the DNA topology using controlled breakage and religation of DNA driven by ATP hydrolysis. DNA gyrase has been validated as the enzyme target of fluoroquinolones (FQs), second-line antibiotics used for the treatment of multidrug-resistant tuberculosis. Mutations around the DNA gyrase DNA-binding site result in the emergence of FQ resistance in M. tuberculosis; inhibition of DNA gyrase ATPase activity is one strategy to overcome this. Here, virtual screening, subsequently validated by biological assays, was applied to select candidate inhibitors of the M. tuberculosis DNA gyrase ATPase activity from the Specs compound library (www.specs.net). Thirty compounds were identified and selected as hits for in vitro biological assays, of which two compounds, G24 and G26, inhibited the growth of M. tuberculosis H37Rv with a minimal inhibitory concentration of 12.5 μg/mL. The two compounds inhibited DNA gyrase ATPase activity with IC50 values of 2.69 and 2.46 μM, respectively, suggesting this to be the likely basis of their antitubercular activity. Models of complexes of compounds G24 and G26 bound to the M. tuberculosis DNA gyrase ATP-binding site, generated by molecular dynamics simulations followed by pharmacophore mapping analysis, showed hydrophobic interactions of inhibitor hydrophobic headgroups and electrostatic and hydrogen bond interactions of the polar tails, which are likely to be important for their inhibition. Decreasing compound lipophilicity by increasing the polarity of these tails then presents a likely route to improving the solubility and activity. Thus, compounds G24 and G26 provide attractive starting templates for the optimization of antitubercular agents that act by targeting DNA gyrase.
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Affiliation(s)
- Bongkochawan Pakamwong
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Paptawan Thongdee
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Bundit Kamsri
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Naruedon Phusi
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Pharit Kamsri
- Division of Chemistry, Faculty of Science, Nakhon Phanom University, Nakhon Phanom 48000, Thailand
| | - Auradee Punkvang
- Division of Chemistry, Faculty of Science, Nakhon Phanom University, Nakhon Phanom 48000, Thailand
| | - Sombat Ketrat
- School of Information Science and Technology, Vidyasirimedhi Institute of Science and Technology, Rayong 21210, Thailand
| | | | - Supa Hannongbua
- Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Kanchiyaphat Ariyachaokun
- Department of Biological Science, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Khomson Suttisintong
- National Nanotechnology Center, NSTDA, 111 Thailand Science Park, Klong Luang, Pathum Thani 12120, Thailand
| | - Sanya Sureram
- Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Prasat Kittakoop
- Chulabhorn Research Institute, Bangkok 10210, Thailand
- Chulabhorn Graduate Institute, Chemical Biology Program, Chulabhorn Royal Academy, Bangkok 10210, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), CHE, Ministry of Education, Bangkok 10300, Thailand
| | - Poonpilas Hongmanee
- Division of Microbiology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - Pitak Santanirand
- Division of Microbiology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - James Spencer
- School of Cellular and Molecular Medicine, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, U.K
| | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Pornpan Pungpo
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
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Kuang W, Zhang H, Wang X, Yang P. Overcoming Mycobacterium tuberculosis through small molecule inhibitors to break down cell wall synthesis. Acta Pharm Sin B 2022; 12:3201-3214. [PMID: 35967276 PMCID: PMC9366312 DOI: 10.1016/j.apsb.2022.04.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/08/2022] [Accepted: 04/19/2022] [Indexed: 12/16/2022] Open
Abstract
Mycobacterium tuberculosis (MTB) utilizes multiple mechanisms to obtain antibiotic resistance during the treatment of infections. In addition, the biofilms, secreted by MTB, can further protect the latter from the contact with drug molecules and immune cells. These self-defending mechanisms lay a formidable challenge to develop effective therapeutic agents against chronic and recurring antibiotic-tolerant MTB infections. Although several inexpensive and effective drugs (isoniazid, rifampicin, pyrazinamide and ethambutol) have been discovered for the treatment regimen, MTB continues to cause considerable morbidity and mortality worldwide. Antibiotic resistance and tolerance remain major global issues, and innovative therapeutic strategies are urgently needed to address the challenges associated with pathogenic bacteria. Gratifyingly, the cell wall synthesis of tubercle bacilli requires the participation of many enzymes which exclusively exist in prokaryotic organisms. These enzymes, absent in human hepatocytes, are recognized as promising targets to develop anti-tuberculosis drug. In this paper, we discussed the critical roles of potential drug targets in regulating cell wall synthesis of MTB. And also, we systematically reviewed the advanced development of novel bioactive compounds or drug leads for inhibition of cell wall synthesis, including their discovery, chemical modification, in vitro and in vivo evaluation.
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Affiliation(s)
- Wenbin Kuang
- State Key Laboratory of Natural Medicines and Jiang Su Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Haolin Zhang
- State Key Laboratory of Natural Medicines and Jiang Su Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Xiao Wang
- State Key Laboratory of Natural Medicines and Jiang Su Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Peng Yang
- State Key Laboratory of Natural Medicines and Jiang Su Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
- Corresponding author.
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Abstract
Whole-genome sequencing (WGS) has shown tremendous potential in rapid diagnosis of drug-resistant tuberculosis (TB). In the current study, we performed WGS on drug-resistant Mycobacterium tuberculosis isolates obtained from Shanghai (n = 137) and Russia (n = 78). We aimed to characterise the underlying and high-frequency novel drug-resistance-conferring mutations, and also create valuable combinations of resistance mutations with high predictive sensitivity to predict multidrug- and extensively drug-resistant tuberculosis (MDR/XDR-TB) phenotype using a bootstrap method. Most strains belonged to L2.2, L4.2, L4.4, L4.5 and L4.8 lineages. We found that WGS could predict 82.07% of phenotypically drug-resistant domestic strains. The prediction sensitivity for rifampicin (RIF), isoniazid (INH), ethambutol (EMB), streptomycin (STR), ofloxacin (OFL), amikacin (AMK) and capreomycin (CAP) was 79.71%, 86.30%, 76.47%, 88.37%, 83.33%, 70.00% and 70.00%, respectively. The mutation combination with the highest sensitivity for MDR prediction was rpoB S450L + rpoB H445A/P + katG S315T + inhA I21T + inhA S94A, with a sensitivity of 92.17% (0.8615, 0.9646), and the mutation combination with highest sensitivity for XDR prediction was rpoB S450L + katG S315T + gyrA D94G + rrs A1401G, with a sensitivity of 92.86% (0.8158, 0.9796). The molecular information presented here will be of particular value for the rapid clinical detection of MDR- and XDR-TB isolates through laboratory diagnosis.
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Knoll KE, Lindeque Z, Adeniji AA, Oosthuizen CB, Lall N, Loots DT. Elucidating the Antimycobacterial Mechanism of Action of Ciprofloxacin Using Metabolomics. Microorganisms 2021; 9:microorganisms9061158. [PMID: 34071153 PMCID: PMC8228629 DOI: 10.3390/microorganisms9061158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/12/2021] [Accepted: 05/18/2021] [Indexed: 12/21/2022] Open
Abstract
In the interest of developing more effective and safer anti-tuberculosis drugs, we used a GCxGC-TOF-MS metabolomics research approach to investigate and compare the metabolic profiles of Mtb in the presence and absence of ciprofloxacin. The metabolites that best describe the differences between the compared groups were identified as markers characterizing the changes induced by ciprofloxacin. Malic acid was ranked as the most significantly altered metabolite marker induced by ciprofloxacin, indicative of an inhibition of the tricarboxylic acid (TCA) and glyoxylate cycle of Mtb. The altered fatty acid, myo-inositol, and triacylglycerol metabolism seen in this group supports previous observations of ciprofloxacin action on the Mtb cell wall. Furthermore, the altered pentose phosphate intermediates, glycerol metabolism markers, glucose accumulation, as well as the reduction in the glucogenic amino acids specifically, indicate a flux toward DNA (as well as cell wall) repair, also supporting previous findings of DNA damage caused by ciprofloxacin. This study further provides insights useful for designing network whole-system strategies for the identification of possible modes of action of various drugs and possibly adaptations by Mtb resulting in resistance.
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Affiliation(s)
- Kirsten E. Knoll
- Department of Human Metabolomics, North-West University, Private Bag x6001, Box 269, Potchefstroom 2531, South Africa; (K.E.K.); (Z.L.); (A.A.A.)
| | - Zander Lindeque
- Department of Human Metabolomics, North-West University, Private Bag x6001, Box 269, Potchefstroom 2531, South Africa; (K.E.K.); (Z.L.); (A.A.A.)
| | - Adetomiwa A. Adeniji
- Department of Human Metabolomics, North-West University, Private Bag x6001, Box 269, Potchefstroom 2531, South Africa; (K.E.K.); (Z.L.); (A.A.A.)
| | - Carel B. Oosthuizen
- Department of Plant and Soil Sciences, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa; (C.B.O.); (N.L.)
| | - Namrita Lall
- Department of Plant and Soil Sciences, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa; (C.B.O.); (N.L.)
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA
| | - Du Toit Loots
- Department of Human Metabolomics, North-West University, Private Bag x6001, Box 269, Potchefstroom 2531, South Africa; (K.E.K.); (Z.L.); (A.A.A.)
- Correspondence: ; Tel.: +27-(0)18-299-1818
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Singh P, Jamal S, Ahmed F, Saqib N, Mehra S, Ali W, Roy D, Ehtesham NZ, Hasnain SE. Computational modeling and bioinformatic analyses of functional mutations in drug target genes in Mycobacterium tuberculosis. Comput Struct Biotechnol J 2021; 19:2423-2446. [PMID: 34025934 PMCID: PMC8113780 DOI: 10.1016/j.csbj.2021.04.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/09/2021] [Accepted: 04/15/2021] [Indexed: 11/29/2022] Open
Abstract
MycoTRAP-DB, a database of mutations and their impact on normal functionality of protein in M.tb genes. Several secondary mutations were identified with significant impact on protein structure and function. Comprehensive information gives insight for screening of suspected hotspots in advance to combat drug resistant TB.
Tuberculosis (TB) continues to be the leading cause of deaths due to its persistent drug resistance and the consequent ineffectiveness of anti-TB treatment. Recent years witnessed huge amount of sequencing data, revealing mutations responsible for drug resistance. However, the lack of an up-to-date repository remains a barrier towards utilization of these data and identifying major mutations-associated with resistance. Amongst all mutations, non-synonymous mutations alter the amino acid sequence of a protein and have a much greater effect on pathogenicity. Hence, this type of gene mutation is of prime interest of the present study. The purpose of this study is to develop an updated database comprising almost all reported substitutions within the Mycobacterium tuberculosis (M.tb) drug target genes rpoB, inhA, katG, pncA, gyrA and gyrB. Various bioinformatics prediction tools were used to assess the structural and biophysical impacts of the resistance causing non-synonymous single nucleotide polymorphisms (nsSNPs) at the molecular level. This was followed by evaluating the impact of these mutations on binding affinity of the drugs to target proteins. We have developed a comprehensive online resource named MycoTRAP-DB (Mycobacterium tuberculosis Resistance Associated Polymorphisms Database) that connects mutations in genes with their structural, functional and pathogenic implications on protein. This database is accessible at http://139.59.12.92. This integrated platform would enable comprehensive analysis and prioritization of SNPs for the development of improved diagnostics and antimycobacterial medications. Moreover, our study puts forward secondary mutations that can be important for prognostic assessments of drug-resistance mechanism and actionable anti-TB drugs.
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Affiliation(s)
- Pooja Singh
- Jamia Hamdard Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India
| | - Salma Jamal
- Jamia Hamdard Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India
| | - Faraz Ahmed
- Jamia Hamdard Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India
| | - Najumu Saqib
- Jamia Hamdard Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India
| | - Seema Mehra
- Jamia Hamdard Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India
| | - Waseem Ali
- Jamia Hamdard Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India
| | - Deodutta Roy
- Department of Environmental and Occupational Health, Florida International University, Miami 33029, USA
| | - Nasreen Z Ehtesham
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Seyed E Hasnain
- Department of Life Sciences, School of Basic Sciences and Research, Sharda University, Greater Noida 201301, India.,Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi (IIT-D), Hauz Khas, New Delhi 110016, India
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Araújo LG, Garcia MT, Zaccariotto TR, Moretti ML, Levy CE, Resende MR. Clinical outcomes and molecular characterization of drug-resistant tuberculosis in pre- and extensively drug-resistant disease based on line probe assays. Braz J Infect Dis 2021; 25:101544. [PMID: 33592172 PMCID: PMC9392081 DOI: 10.1016/j.bjid.2021.101544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/12/2020] [Accepted: 12/26/2020] [Indexed: 12/04/2022] Open
Abstract
Multidrug-resistant tuberculosis (MDR-TB) represents a significant impact in transmission, outcome, and health costs. The World Health Organization recommends implementation of rapid diagnostic methods for multidrug-resistance detection. This study was performed to evaluate the frequency of pre- and extensively drug resistant tuberculosis (pre-XDR-TB and XDR-TB) among MDR-TB patients, the pattern of resistance mutations for fluoroquinolones and the clinical outcome. Adult patients followed at a Brazilian regional reference center for TB, from January 2013 to June 2019 were included. Stored Mycobacterium tuberculosis (Mtb) cultures were recovered, the DNA was extracted, and the susceptibility test was performed using the line probe assay for second line antimycobacterial drugs, Genotype MTBDRsl version 2.0 (Hain Lifescience, CmbH, Germany). Among 33 MDR-TB included patients, we diagnosed XDR-TB or pre-XDR in five (15%) cases. Of these, mutations related to fluoroquinolones resistance were observed in four Mtb isolates, including one who had no phenotypic resistance profile. In two other patients with phenotypic resistance to ofloxacin, genotypic resistance was not found. Case fatality rate was 60% in pre/XDR-TB group, compared to 3.6% in the remaining of patients. This study observed few cases of pre-XDR and XDR-TB among a MDR-TB cohort. Phenotypic and genotypic assays presented good agreement. Clinical outcome was more favorable for patients with susceptibility to fluoroquinolones and injectable drugs.
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Affiliation(s)
- Lauane G Araújo
- Graduate University of Campinas, Faculty of Medical Sciences, Program of Internal Medicine, Campinas, SP, Brazil
| | - Márcia T Garcia
- Clinical Hospital of State University of Campinas, Epidemiological Surveillance Section, Campinas, SP, Brazil
| | - Tânia R Zaccariotto
- Clinical Hospital of State University of Campinas, Clinical Pathology Division, Clinical Microbiology Laboratory, Campinas, SP, Brazil
| | - Maria Luiza Moretti
- Graduate University of Campinas, Faculty of Medical Sciences, Program of Internal Medicine, Campinas, SP, Brazil; Clinical Hospital of State University of Campinas, Epidemiological Surveillance Section, Campinas, SP, Brazil; State University of Campinas, Faculty of Medical Sciences, Department of Internal Medicine, Campinas, SP, Brazil
| | - Carlos E Levy
- Clinical Hospital of State University of Campinas, Clinical Pathology Division, Clinical Microbiology Laboratory, Campinas, SP, Brazil; State University of Campinas, Faculty of Medical Sciences, Department of Clinical Pathology, Campinas, SP, Brazil
| | - Mariângela R Resende
- Graduate University of Campinas, Faculty of Medical Sciences, Program of Internal Medicine, Campinas, SP, Brazil; Clinical Hospital of State University of Campinas, Epidemiological Surveillance Section, Campinas, SP, Brazil; State University of Campinas, Faculty of Medical Sciences, Department of Internal Medicine, Campinas, SP, Brazil.
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13
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Detection of Second Line Drug Resistance among Drug Resistant Mycobacterium Tuberculosis Isolates in Botswana. Pathogens 2019; 8:pathogens8040208. [PMID: 31661825 PMCID: PMC6963291 DOI: 10.3390/pathogens8040208] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/14/2019] [Accepted: 10/23/2019] [Indexed: 11/23/2022] Open
Abstract
The emergence and transmission of multidrug resistant (MDR) and extensively drug resistant (XDR) Mycobacterium tuberculosis (M.tb) strains is a threat to global tuberculosis (TB) control. The early detection of drug resistance is critical for patient management. The aim of this study was to determine the proportion of isolates with additional second-line resistance among rifampicin and isoniazid resistant and MDR-TB isolates. A total of 66 M.tb isolates received at the National Tuberculosis Reference Laboratory between March 2012 and October 2013 with resistance to isoniazid, rifampicin or both were analyzed in this study. The genotypes of the M.tb isolates were determined by spoligotyping and second-line drug susceptibility testing was done using the Hain Genotype MTBDRsl line probe assay version 2.0. The treatment outcomes were defined according to the Botswana national and World Health Organization (WHO) guidelines. Of the 57 isolates analyzed, 33 (58%) were MDR-TB, 4 (7%) were additionally resistant to flouroquinolones and 3 (5%) were resistant to both fluoroquinolones and second-line injectable drugs. The most common fluoroquinolone resistance-conferring mutation detected was gyrA A90V. All XDR-TB cases remained smear or culture positive throughout the treatment. Our study findings indicate the importance of monitoring drug resistant TB cases to ensure rapid detection of second-line drug resistance.
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14
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Li Q, Gao H, Zhang Z, Tian Y, Liu T, Wang Y, Lu J, Liu Y, Dai E. Mutation and Transmission Profiles of Second-Line Drug Resistance in Clinical Isolates of Drug-Resistant Mycobacterium tuberculosis From Hebei Province, China. Front Microbiol 2019; 10:1838. [PMID: 31447823 PMCID: PMC6692474 DOI: 10.3389/fmicb.2019.01838] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 07/25/2019] [Indexed: 11/30/2022] Open
Abstract
The emergence of drug-resistant tuberculosis (TB) is involved in ineffective treatment of TB, especially multidrug resistant/extensively resistant TB (MDR/XDR-TB), leading to acquired resistance and transmission of drug-resistant strains. Second-line drugs (SLD), including both fluoroquinolones and injectable drugs, were commonly proved to be the effective drugs for treatment of drug-resistant TB. The purpose of this study was to investigate the prevalence of SLD-resistant strains and its specific mutations in drug-resistant Mycobacterium tuberculosis clinical isolates, and to acknowledge the transmission pattern of SLD resistance strains in Hebei. The genes gyrA, gyrB, rrs, eis promoter and tlyA of 257 drug-resistant clinical isolates were sequenced to identify mutations that could be responsible for resistance against fluoroquinolones and second-line injectable drugs. Each isolate was genotyped by Spoligotyping and 15-loci MIRU-VNTR. Our results indicated that 48.2% isolates were resistant to at least one of five SLD. Of them, 37.7% isolates were resistant to fluoroquinolones and 24.5% isolates were resistant to second-line injectable drugs. Mutations in genes gyrA, gyrB, rrs, eis promoter and tlyA were detected in 73 (75.3%), 7 (7.2%), 24 (38.1%), 5 (7.9%), and 3 (4.8%) isolates, respectively. The most prevalent mutations were the D94G (23.7%) in gyrA gene and the A1401G (33.3%) in rrs gene. A combination of gyrA, rrs and eis promoter can act as a valuable predicator for predicting XDR phenotype. These results highlight the development of rapid diagnosis are the effective manners for the control of SLD-TB or XDR-TB.
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Affiliation(s)
- Qianlin Li
- Department of Epidemiology and Statistics, North China University of Science and Technology, Tangshan, China
| | - Huixia Gao
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
| | - Zhi Zhang
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
| | - Yueyang Tian
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
| | - Tengfei Liu
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
| | - Yuling Wang
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
| | - Jianhua Lu
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
| | - Yuzhen Liu
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
| | - Erhei Dai
- Department of Laboratory Medicine, The Fifth Affiliated Hospital of Shijiazhuang, North China University of Science and Technology, Shijiazhuang, China
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15
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Faksri K, Kaewprasert O, Ong RTH, Suriyaphol P, Prammananan T, Teo YY, Srilohasin P, Chaiprasert A. Comparisons of whole-genome sequencing and phenotypic drug susceptibility testing for Mycobacterium tuberculosis causing MDR-TB and XDR-TB in Thailand. Int J Antimicrob Agents 2019; 54:109-116. [PMID: 30981926 DOI: 10.1016/j.ijantimicag.2019.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 02/26/2019] [Accepted: 04/06/2019] [Indexed: 01/12/2023]
Abstract
Drug-resistant tuberculosis (TB) is a major public health problem. There is little information regarding the genotypic-phenotypic association of anti-TB drugs, especially for second-line drugs. This study compared phenotypic drug susceptibility testing (DST) with predictions based on whole-genome sequencing (WGS) data for 266 Mycobacterium tuberculosis isolates. Phenotypic DST used the standard proportional method. Clinical isolates of M. tuberculosis collected in Thailand between 1998 and 2013 comprised 51 drug-sensitive strains, six mono-resistant strains, two multiple-resistant strains, 88 multi-drug-resistant strains, 95 pre-extensively drug-resistant strains and 24 extensively drug-resistant strains. WGS analysis was performed using the computer programs PhyResSE and TB-Profiler. TB-Profiler had higher average concordance with phenotypic DST than PhyResSE for both first-line (91.96% vs. 91.4%) and second-line (79.67% vs. 78.20%) anti-TB drugs. The average sensitivity for all anti-TB drugs was also higher (83.13% vs. 72.08%) with slightly lower specificity (83.50% vs. 86.68%). Regardless of the program used, isoniazid, rifampicin and amikacin had the highest concordance with phenotypic DST (96.2%, 93.5% and 95.6%, respectively). Ethambutol, ethionamide and fluoroquinolones had the lowest concordance (87.34%, 81.44% and 73.85%, respectively). Concordance rates of ofloxacin (a second-generation fluoroquinolone), levofloxacin, moxifloxacin and gatifloxacin (third- and fourth-generation fluoroquinolones) were 91.79%, 76.62%, 72.64% and 57.35%, respectively. Discordance between phenotypic and WGS-based DSTs may be due, in part, to the choice of critical concentration and variable reproducibility of the phenotypic tests. It may also be due to limitations of the mutation databases (especially for the second-line drugs) and the analysis program used. Mutations related to fluoroquinolone resistance, especially the later generations, need to be identified.
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Affiliation(s)
- Kiatichai Faksri
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Research and Diagnostic Centre for Emerging Infectious Diseases, Khon Kaen University, Khon Kaen, Thailand.
| | - Orawee Kaewprasert
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Research and Diagnostic Centre for Emerging Infectious Diseases, Khon Kaen University, Khon Kaen, Thailand
| | - Rick Twee-Hee Ong
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Prapat Suriyaphol
- Bioinformatics and Data Management for Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Therdsak Prammananan
- National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science and Technology, Pathum Thani, Thailand
| | - Yik-Ying Teo
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore; Genome Institute of Singapore, Singapore; Department of Statistics and Applied Probability, National University of Singapore, Singapore; Life Sciences Institute, National University of Singapore, Singapore
| | - Prapaporn Srilohasin
- Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Angkana Chaiprasert
- Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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16
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Chikhale RV, Barmade MA, Murumkar PR, Yadav MR. Overview of the Development of DprE1 Inhibitors for Combating the Menace of Tuberculosis. J Med Chem 2018; 61:8563-8593. [PMID: 29851474 DOI: 10.1021/acs.jmedchem.8b00281] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Decaprenylphosphoryl-β-d-ribose 2'-epimerase (DprE1), a vital enzyme for cell wall synthesis, plays a crucial role in the formation of lipoarabinomannan and arabinogalactan. It was first reported as a druggable target on the basis of inhibitors discovered in high throughput screening of a drug library. Since then, inhibitors with different types of chemical scaffolds have been reported for their activity against this enzyme. Formation of a covalent or noncovalent bond by the interacting ligand with the enzyme causes loss of its catalytic activity which ultimately leads to the death of the mycobacterium. This Perspective describes various DprE1 inhibitors as anti-TB agents reported to date.
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Affiliation(s)
- Rupesh V Chikhale
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India.,School of Health Sciences, Division of Pharmacy and Optometry , University of Manchester , Manchester M13 9PL , U.K
| | - Mahesh A Barmade
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India
| | - Prashant R Murumkar
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India
| | - Mange Ram Yadav
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India
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17
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Luo T, Yuan J, Peng X, Yang G, Mi Y, Sun C, Wang C, Zhang C, Bao L. Double mutation in DNA gyrase confers moxifloxacin resistance and decreased fitness of Mycobacterium smegmatis. J Antimicrob Chemother 2018; 72:1893-1900. [PMID: 28387828 DOI: 10.1093/jac/dkx110] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 03/13/2017] [Indexed: 11/13/2022] Open
Abstract
Objectives Ofloxacin and moxifloxacin are the most commonly used fluoroquinolones (FQs) for the treatment of tuberculosis. As a new generation FQ, moxifloxacin has been recommended for the treatment of ofloxacin-resistant TB. However, the mechanism by which ofloxacin-resistant Mycobacterium tuberculosis further gains resistance to moxifloxacin remains unclear. Methods We used Mycobacterium smegmatis as a model for studying FQ resistance in M. tuberculosis . Moxifloxacin-resistant M. smegmatis was selected in vitro based on strains with primary ofloxacin resistance. The gyrA and gyrB genes of the resistant strains were sequenced to identify resistance-associated mutations. An in vitro competition assay was applied to explore the influence of gyrA / gyrB mutations on bacterial fitness. Finally, we evaluated the clinical relevance of our findings by analysing the WGS data of 1984 globally collected M. tuberculosis strains. Results A total of 57 moxifloxacin-resistant M. smegmatis strains based on five ofloxacin-resistant strains were obtained. Sequencing results revealed that all moxifloxacin-resistant strains harboured second-step mutations in gyrA or gyrB . The relative fitnesses of the double-mutation strains varied from 0.65 to 0.93 and were mostly lower than those of their mono-mutation parents. From the genomic data, we identified 37 clinical M. tuberculosis strains harbouring double mutations in gyrA and/or gyrB and 36 of them carried at least one low-level FQ-resistance mutation. Conclusions Double mutation in DNA gyrase leads to moxifloxacin resistance and decreased fitness in M. smegmatis . Under current dosing of moxifloxacin, double mutations mainly happened in M. tuberculosis strains with primary low-level resistance mutations.
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Affiliation(s)
- Tao Luo
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Jinning Yuan
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Xuan Peng
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Guoping Yang
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Youjun Mi
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Changfeng Sun
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Chuhan Wang
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Chunxi Zhang
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
| | - Lang Bao
- Laboratory of Infection and Immunity, West China Center of Medical Sciences, Sichuan University, Chengdu 610041, China
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18
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Leechawengwongs M, Prammananan T, Jaitrong S, Billamas P, Makhao N, Thamnongdee N, Thanormchat A, Phurattanakornkul A, Rattanarangsee S, Ratanajaraya C, Disratthakit A, Chaiprasert A. In Vitro Activity and MIC of Sitafloxacin against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis Isolated in Thailand. Antimicrob Agents Chemother 2018; 62:e00825-17. [PMID: 29061759 PMCID: PMC5740303 DOI: 10.1128/aac.00825-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 09/06/2017] [Indexed: 11/20/2022] Open
Abstract
New fluoroquinolones (FQs) have been shown to be more active against drug-resistant Mycobacterium tuberculosis strains than early FQs, such as ofloxacin. Sitafloxacin (STFX) is a new fluoroquinolone with in vitro activity against a broad range of bacteria, including M. tuberculosis This study aimed to determine the in vitro activity of STFX against all groups of drug-resistant strains, including multidrug-resistant M. tuberculosis (MDR M. tuberculosis), MDR M. tuberculosis with quinolone resistance (pre-XDR), and extensively drug-resistant (XDR) strains. A total of 374 drug-resistant M. tuberculosis strains were tested for drug susceptibility by the conventional proportion method, and 95 strains were randomly submitted for MIC determination using the microplate alamarBlue assay (MABA). The results revealed that all the drug-resistant strains were susceptible to STFX at a critical concentration of 2 μg/ml. Determination of the MIC90s of the strains showed different MIC levels; MDR M. tuberculosis strains had a MIC90 of 0.0625 μg/ml, whereas pre-XDR and XDR M. tuberculosis strains had identical MIC90s of 0.5 μg/ml. Common mutations within the quinolone resistance-determining region (QRDR) of gyrA and/or gyrB did not confer resistance to STFX, except that double mutations of GyrA at Ala90Val and Asp94Ala were found in strains with a MIC of 1.0 μg/ml. The results indicated that STFX had potent in vitro activity against all the groups of drug-resistant M. tuberculosis strains and should be considered a new repurposed drug for treatment of multidrug-resistant and extensively drug-resistant TB.
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Affiliation(s)
- Manoon Leechawengwongs
- Vichaiyut Hospital, Bangkok, Thailand
- Drug Resistant Tuberculosis Research Fund, Siriraj Foundation, Bangkok, Thailand
| | - Therdsak Prammananan
- Drug Resistant Tuberculosis Research Fund, Siriraj Foundation, Bangkok, Thailand
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science and Technology, Pathumthani, Thailand
| | - Sarinya Jaitrong
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science and Technology, Pathumthani, Thailand
| | - Pamaree Billamas
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science and Technology, Pathumthani, Thailand
| | - Nampueng Makhao
- Drug Resistant Tuberculosis Research Fund, Siriraj Foundation, Bangkok, Thailand
| | - Nongnard Thamnongdee
- Drug Resistant Tuberculosis Research Fund, Siriraj Foundation, Bangkok, Thailand
| | - Arirat Thanormchat
- Drug Resistant Tuberculosis Research Fund, Siriraj Foundation, Bangkok, Thailand
| | | | | | - Chate Ratanajaraya
- Drug Resistant Tuberculosis Research Fund, Siriraj Foundation, Bangkok, Thailand
| | - Areeya Disratthakit
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Angkana Chaiprasert
- Drug Resistant Tuberculosis Research Fund, Siriraj Foundation, Bangkok, Thailand
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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19
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Naidoo A, Naidoo K, McIlleron H, Essack S, Padayatchi N. A Review of Moxifloxacin for the Treatment of Drug-Susceptible Tuberculosis. J Clin Pharmacol 2017; 57:1369-1386. [PMID: 28741299 DOI: 10.1002/jcph.968] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 05/21/2017] [Indexed: 11/08/2022]
Abstract
Moxifloxacin, an 8-methoxy quinolone, is an important drug in the treatment of multidrug-resistant tuberculosis and is being investigated in novel drug regimens with pretomanid, bedaquiline, and pyrazinamide, or rifapentine, for the treatment of drug-susceptible tuberculosis. Early results of these studies are promising. Although current evidence does not support the use of moxifloxacin in treatment-shortening regimens for drug-susceptible tuberculosis, it may be recommended in patients unable to tolerate standard first-line drug regimens or for isoniazid monoresistance. Evidence suggests that the standard 400-mg dose of moxifloxacin used in the treatment of tuberculosis may be suboptimal in some patients, leading to worse tuberculosis treatment outcomes and emergence of drug resistance. Furthermore, a drug interaction with the rifamycins results in up to 31% reduced plasma concentrations of moxifloxacin when these are combined for treatment of drug-susceptible tuberculosis, although the clinical relevance of this interaction is unclear. Moxifloxacin exhibits extensive interindividual pharmacokinetic variability. Higher doses of moxifloxacin may be needed to achieve drug exposures required for improved clinical outcomes. Further study is, however, needed to determine the safety of proposed higher doses and clinically validated targets for drug exposure to moxifloxacin associated with improved tuberculosis treatment outcomes. We discuss in this review the evidence for the use of moxifloxacin in drug-susceptible tuberculosis and explore the role of moxifloxacin pharmacokinetics, pharmacodynamics, and drug interactions with rifamycins, on tuberculosis treatment outcomes when used in first-line tuberculosis drug regimens.
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Affiliation(s)
- Anushka Naidoo
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Kogieleum Naidoo
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa.,MRC-CAPRISA HIV-TB Pathogenesis and Treatment Research Unit, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Sabiha Essack
- Antimicrobial Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Nesri Padayatchi
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa.,MRC-CAPRISA HIV-TB Pathogenesis and Treatment Research Unit, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
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20
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Yi L, Aono A, Chikamatsu K, Igarashi Y, Yamada H, Takaki A, Mitarai S. In vitro activity of sitafloxacin against Mycobacterium tuberculosis with gyrA/B mutations isolated in Japan. J Med Microbiol 2017; 66:770-776. [PMID: 28598311 DOI: 10.1099/jmm.0.000493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Purpose. Sitafloxacin (SFX) is a new fluoroquinolone (FQ) that has shown a strong bactericidal effect against Mycobacterium tuberculosis (Mtb) in vitro. However, data on SFX efficacy against Mtb with gyrA/B mutations and its epidemiological cut-off (ECOFF) value remain limited. Therefore, we evaluated and compared the in vitro activity of SFX against gyrA/B-mutant Mtb to that of moxifloxacin (MFX), levofloxacin (LFX) and ciprofloxacin (CFX), and determined the ECOFF for SFX.Methodology. A total of 109 clinical Mtb isolates, including 73 multidrug-resistant (MDR) isolates, were subjected to minimum inhibitory concentration (MIC) analysis in oleic-albumin-dextrose-catalase (OADC)-supplemented Middlebrook 7H9 medium. Our results showed that SFX had lower cumulative MIC than MFX, LFX and CFX. Furthermore, we performed direct DNA sequencing of the quinolone-resistance-determining regions (QRDRs).Results. We identified the following mutations: D94G, D94A, A90V, D94H, D94N and G88A in gyrA; and A543V, A543T, E540D, R485C, D500A, I552S and D577A in gyrB. Based on our results, an ECOFF of 0.125 µg ml-1 was proposed for SFX. With this ECOFF, 15 % of LFX-resistant isolates with MIC ≥2 µg ml-1 were susceptible to SFX.Conclusion. SFX had the lowest cumulative MIC and a relatively low ECOFF value against Mtb, indicating that SFX was not only more effective against gyrA-mutant isolates, but also MDR isolates in Japan.
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Affiliation(s)
- Lina Yi
- Department of Basic Mycobacteriology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Japan.,Respiratory Disease Center, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Japan
| | - Akio Aono
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Japan
| | - Kinuyo Chikamatsu
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Japan
| | - Yuriko Igarashi
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Japan
| | - Hiroyuki Yamada
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Japan
| | - Akiko Takaki
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Japan
| | - Satoshi Mitarai
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Japan.,Department of Basic Mycobacteriology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
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21
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Pandey B, Grover S, Tyagi C, Goyal S, Jamal S, Singh A, Kaur J, Grover A. Double Mutants in DNA Gyrase Lead to Ofloxacin Resistance in Mycobacterium tuberculosis. J Cell Biochem 2017; 118:2950-2957. [PMID: 28247939 DOI: 10.1002/jcb.25954] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 02/24/2017] [Indexed: 11/10/2022]
Abstract
Fluoroquinolones are among the most important classes of highly effective antibacterial drugs, exhibiting wide range of activity to cure infectious diseases. Ofloxacin is second generation fluoroquinolone approved by FDA for the treatment of tuberculosis by selectively inhibiting DNA gyrase. However, the emergence of drug resistance owing to mutations in DNA gyrase poses intimidating challenge for the effective therapy of this drug. The double mutants GyrAA90V GyrBD500N and GyrAA90V GyrBT539N are reported to be implicated in conferring higher levels of OFX resistance. The present study was designed to unravel the molecular principles behind development of resistance by the bug against fluoroquinolones. Our results highlighted that polar interactions play critical role in the development of drug resistance and highlight the significant correlation between the free energy calculations predicted by MM-PBSA and stability of the ligand-bound complexes. Modifications at the OFX binding pocket due to amino acid substitution leads to fewer hydrogen bonds in mutants DNA gyrase-OFX complex, which determined the low susceptibility of the ligand in inhibiting the mutant protein. This study provides a structural rationale to the mutation-based resistance to ofloxacin and will pave way for development potent fluoroquinolone-based resistant-defiant drugs. J. Cell. Biochem. 118: 2950-2957, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Bharati Pandey
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India
| | - Sonam Grover
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Chetna Tyagi
- Department of Microbiology, University of Szeged, Hungary, H-6720 Szeged, Dugonics Square 13, Hungary
| | - Sukriti Goyal
- Department of Bioscience and Biotechnology, Banasthali University, Tonk, 304022, Rajasthan, India
| | - Salma Jamal
- Department of Bioscience and Biotechnology, Banasthali University, Tonk, 304022, Rajasthan, India
| | - Aditi Singh
- Department of Biotechnology, TERI University, New Delhi, 110070, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India
| | - Abhinav Grover
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
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22
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Dheda K, Gumbo T, Maartens G, Dooley KE, McNerney R, Murray M, Furin J, Nardell EA, London L, Lessem E, Theron G, van Helden P, Niemann S, Merker M, Dowdy D, Van Rie A, Siu GKH, Pasipanodya JG, Rodrigues C, Clark TG, Sirgel FA, Esmail A, Lin HH, Atre SR, Schaaf HS, Chang KC, Lange C, Nahid P, Udwadia ZF, Horsburgh CR, Churchyard GJ, Menzies D, Hesseling AC, Nuermberger E, McIlleron H, Fennelly KP, Goemaere E, Jaramillo E, Low M, Jara CM, Padayatchi N, Warren RM. The epidemiology, pathogenesis, transmission, diagnosis, and management of multidrug-resistant, extensively drug-resistant, and incurable tuberculosis. THE LANCET. RESPIRATORY MEDICINE 2017; 5:S2213-2600(17)30079-6. [PMID: 28344011 DOI: 10.1016/s2213-2600(17)30079-6] [Citation(s) in RCA: 382] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 10/24/2016] [Accepted: 12/08/2016] [Indexed: 12/25/2022]
Abstract
Global tuberculosis incidence has declined marginally over the past decade, and tuberculosis remains out of control in several parts of the world including Africa and Asia. Although tuberculosis control has been effective in some regions of the world, these gains are threatened by the increasing burden of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. XDR tuberculosis has evolved in several tuberculosis-endemic countries to drug-incurable or programmatically incurable tuberculosis (totally drug-resistant tuberculosis). This poses several challenges similar to those encountered in the pre-chemotherapy era, including the inability to cure tuberculosis, high mortality, and the need for alternative methods to prevent disease transmission. This phenomenon mirrors the worldwide increase in antimicrobial resistance and the emergence of other MDR pathogens, such as malaria, HIV, and Gram-negative bacteria. MDR and XDR tuberculosis are associated with high morbidity and substantial mortality, are a threat to health-care workers, prohibitively expensive to treat, and are therefore a serious public health problem. In this Commission, we examine several aspects of drug-resistant tuberculosis. The traditional view that acquired resistance to antituberculous drugs is driven by poor compliance and programmatic failure is now being questioned, and several lines of evidence suggest that alternative mechanisms-including pharmacokinetic variability, induction of efflux pumps that transport the drug out of cells, and suboptimal drug penetration into tuberculosis lesions-are likely crucial to the pathogenesis of drug-resistant tuberculosis. These factors have implications for the design of new interventions, drug delivery and dosing mechanisms, and public health policy. We discuss epidemiology and transmission dynamics, including new insights into the fundamental biology of transmission, and we review the utility of newer diagnostic tools, including molecular tests and next-generation whole-genome sequencing, and their potential for clinical effectiveness. Relevant research priorities are highlighted, including optimal medical and surgical management, the role of newer and repurposed drugs (including bedaquiline, delamanid, and linezolid), pharmacokinetic and pharmacodynamic considerations, preventive strategies (such as prophylaxis in MDR and XDR contacts), palliative and patient-orientated care aspects, and medicolegal and ethical issues.
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Affiliation(s)
- Keertan Dheda
- Lung Infection and Immunity Unit, Department of Medicine, Division of Pulmonology and UCT Lung Institute, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa.
| | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Gary Maartens
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Kelly E Dooley
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ruth McNerney
- Lung Infection and Immunity Unit, Department of Medicine, Division of Pulmonology and UCT Lung Institute, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa
| | - Megan Murray
- Department of Global Health and Social Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Jennifer Furin
- Department of Global Health and Social Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Edward A Nardell
- TH Chan School of Public Health, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Leslie London
- School of Public Health and Medicine, University of Cape Town, Cape Town, South Africa
| | | | - Grant Theron
- SA MRC Centre for Tuberculosis Research/DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Stellenbosch University, Tygerberg, South Africa
| | - Paul van Helden
- SA MRC Centre for Tuberculosis Research/DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Stellenbosch University, Tygerberg, South Africa
| | - Stefan Niemann
- Molecular and Experimental Mycobacteriology, Research Center Borstel, Borstel, Schleswig-Holstein, Germany; German Centre for Infection Research (DZIF), Partner Site Borstel, Borstel, Schleswig-Holstein, Germany
| | - Matthias Merker
- Molecular and Experimental Mycobacteriology, Research Center Borstel, Borstel, Schleswig-Holstein, Germany
| | - David Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Annelies Van Rie
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; International Health Unit, Epidemiology and Social Medicine, Faculty of Medicine, University of Antwerp, Antwerp, Belgium
| | - Gilman K H Siu
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Jotam G Pasipanodya
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Camilla Rodrigues
- Department of Microbiology, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, India
| | - Taane G Clark
- Faculty of Infectious and Tropical Diseases and Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Frik A Sirgel
- SA MRC Centre for Tuberculosis Research/DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Stellenbosch University, Tygerberg, South Africa
| | - Aliasgar Esmail
- Lung Infection and Immunity Unit, Department of Medicine, Division of Pulmonology and UCT Lung Institute, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa
| | - Hsien-Ho Lin
- Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan
| | - Sachin R Atre
- Center for Clinical Global Health Education (CCGHE), Johns Hopkins University, Baltimore, MD, USA; Medical College, Hospital and Research Centre, Pimpri, Pune, India
| | - H Simon Schaaf
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Kwok Chiu Chang
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong SAR, China
| | - Christoph Lange
- Division of Clinical Infectious Diseases, German Center for Infection Research, Research Center Borstel, Borstel, Schleswig-Holstein, Germany; International Health/Infectious Diseases, University of Lübeck, Lübeck, Germany; Department of Medicine, Karolinska Institute, Stockholm, Sweden; Department of Medicine, University of Namibia School of Medicine, Windhoek, Namibia
| | - Payam Nahid
- Division of Pulmonary and Critical Care, San Francisco General Hospital, University of California, San Francisco, CA, USA
| | - Zarir F Udwadia
- Pulmonary Department, Hinduja Hospital & Research Center, Mumbai, India
| | | | - Gavin J Churchyard
- Aurum Institute, Johannesburg, South Africa; School of Public Health, University of Witwatersrand, Johannesburg, South Africa; Advancing Treatment and Care for TB/HIV, South African Medical Research Council, Johannesburg, South Africa
| | - Dick Menzies
- Montreal Chest Institute, McGill University, Montreal, QC, Canada
| | - Anneke C Hesseling
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Eric Nuermberger
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Kevin P Fennelly
- Pulmonary Clinical Medicine Section, Division of Intramural Research, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Eric Goemaere
- MSF South Africa, Cape Town, South Africa; School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
| | | | - Marcus Low
- Treatment Action Campaign, Johannesburg, South Africa
| | | | - Nesri Padayatchi
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), MRC HIV-TB Pathogenesis and Treatment Research Unit, Durban, South Africa
| | - Robin M Warren
- SA MRC Centre for Tuberculosis Research/DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Stellenbosch University, Tygerberg, South Africa
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