1
|
Lin YJ, Zou Y, Karlsson MO, Svensson EM. A pharmacometric multistate model for predicting long-term treatment outcomes of patients with pulmonary TB. J Antimicrob Chemother 2024:dkae256. [PMID: 39087258 DOI: 10.1093/jac/dkae256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 07/02/2024] [Indexed: 08/02/2024] Open
Abstract
BACKGROUND Studying long-term treatment outcomes of TB is time-consuming and impractical. Early and reliable biomarkers reflecting treatment response and capable of predicting long-term outcomes are urgently needed. OBJECTIVES To develop a pharmacometric multistate model to evaluate the link between potential predictors and long-term outcomes. METHODS Data were obtained from two Phase II clinical trials (TMC207-C208 and TMC207-C209) with bedaquiline on top of a multidrug background regimen. Patients were typically followed throughout a 24 week investigational treatment period plus a 96 week follow-up period. A five-state multistate model (active TB, converted, recurrent TB, dropout, and death) was developed to describe observed transitions. Evaluated predictors included patient characteristics, baseline TB disease severity and on-treatment biomarkers. RESULTS A fast bacterial clearance in the first 2 weeks and low TB bacterial burden at baseline increased probability to achieve conversion, whereas patients with XDR-TB were less likely to reach conversion. Higher estimated mycobacterial load at the end of 24 week treatment increased the probability of recurrence. At 120 weeks, the model predicted 55% (95% prediction interval, 50%-60%), 6.5% (4.2%-9.0%) and 7.5% (5.2%-10%) of patients in converted, recurrent TB and death states, respectively. Simulations predicted a substantial increase of recurrence after 24 weeks in patients with slow bacterial clearance regardless of baseline bacterial burden. CONCLUSIONS The developed multistate model successfully described TB treatment outcomes. The multistate modelling framework enables prediction of several outcomes simultaneously, and allows mechanistically sound investigation of novel promising predictors. This may help support future biomarker evaluation, clinical trial design and analysis.
Collapse
Affiliation(s)
- Yu-Jou Lin
- Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Yuanxi Zou
- Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | | | - Elin M Svensson
- Department of Pharmacy, Uppsala University, Uppsala, Sweden
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
2
|
Tarekegn BG, Tientcheu LD, Decker J, Bell AJ, Mukamolova GV, Kampmann B, Messele G, Abeje T, Aseffa A, Dockrell HM, Haldar P, Barer MR, Garton NJ. Host and pathogen factors that influence variability of Mycobacterium tuberculosis lipid body content in sputum from patients with tuberculosis: an observational study. THE LANCET. MICROBE 2024:S2666-5247(24)00108-3. [PMID: 38906163 DOI: 10.1016/s2666-5247(24)00108-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 04/10/2024] [Accepted: 04/15/2024] [Indexed: 06/23/2024]
Abstract
BACKGROUND High proportions of Mycobacterium tuberculosis cells in sputum containing triacylglycerol-rich lipid bodies have been shown to be associated with treatment failure or relapse following antituberculous chemotherapy. Although lipid body determination is a potential biomarker for supporting clinical trial and treatment decisions, factors influencing variability in sputum frequencies of lipid body-positive (%LB+) M tuberculosis in patients are unknown. We aimed to test our hypothesis that exposure to host-generated NO and M tuberculosis strains are factors associated with differences in sputum %LB+. METHODS In this observational study, we determined %LB+ frequencies before treatment by microscopy in patients with smear-positive tuberculosis from two separate prospective observational study settings (Gondar, Ethiopia, recruited between May 1, 2010, and April 30, 2011, and Fajara, The Gambia, who provided sputum samples before treatment between May 5, 2010, and Dec 22, 2011). In Ethiopia, fractional exhaled nitric oxide (FeNO) was measured as a biomarker of host NO, and M tuberculosis strain differences were determined by spoligotyping. Treatment response was assessed by percentage weight change after 7 months. In The Gambia, treatment responses were assessed as change in BMI and radiographic burden of disease after 6 months. Sputum M tuberculosis isolates were studied in vitro for their %LB+ and triacylglycerol synthase 1 (tgs1) mRNA responses to NO exposure. Propidium iodide staining was used as a measure of NO strain toxicity. Correlation between in vitro %LB+ frequencies following NO exposure and those of the same strain in sputum was examined with linear regression and Dunnett's multiple comparison test. FINDINGS In Ethiopia, 73 patients who were smear positive for pulmonary tuberculosis were recruited (43 [59%] were male and 30 [41%] were female). Of these, the %LB+ in the sputum of 59 patients showed linear correlation with log10 FeNO (r2=0·28; p<0·0001) and an association with strain spoligotype was suggested. Seven M tuberculosis strains from The Gambia showed different dose-responses to NO in vitro, demonstrated by changing lipid body content, tgs1 transcription, and bacterial toxicity. In sputum %LB+ frequencies correlated with in vitro %LB+ responses to NO of the corresponding isolate. In a subset of 34 patients across both cohorts, higher sputum %LB+ frequencies before treatment were associated with weaker responses to treatment than lower sputum %LB+ frequencies. INTERPRETATION M tuberculosis strain and exposure to host-generated NO are associated with sputum %LB+. Our results support the use of M tuberculosis strain-dependent sputum %LB+ as a predictive biomarker of treatment response. FUNDING The Medical Research Council, the University of Leicester, and the University of Gondar.
Collapse
Affiliation(s)
- Baye G Tarekegn
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Department of Medical Microbiology, University of Gondar, Gondar, Ethiopia
| | - Leopold D Tientcheu
- Medical Research Council Unit, The Gambia at London School of Hygiene & Tropical Medicine, Vaccines and Immunity Theme, Fajara, The Gambia; Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Jonathan Decker
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Andrew J Bell
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Galina V Mukamolova
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Leicester Tuberculosis Research Group, University of Leicester, Leicester, UK; National Institute for Health and Care Research Leicester Biomedical Research Centre, Leicester, UK
| | - Beate Kampmann
- Medical Research Council Unit, The Gambia at London School of Hygiene & Tropical Medicine, Vaccines and Immunity Theme, Fajara, The Gambia; Institut für Internationale Gesundheit and Centre for Global Health, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Gashaw Messele
- Department of Surgery, University of Gondar, Gondar, Ethiopia
| | - Tadeye Abeje
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Hazel M Dockrell
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Pranabashis Haldar
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Leicester Tuberculosis Research Group, University of Leicester, Leicester, UK; National Institute for Health and Care Research Leicester Biomedical Research Centre, Leicester, UK
| | - Michael R Barer
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Leicester Tuberculosis Research Group, University of Leicester, Leicester, UK; National Institute for Health and Care Research Leicester Biomedical Research Centre, Leicester, UK; Department of Clinical Microbiology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Natalie J Garton
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Leicester Tuberculosis Research Group, University of Leicester, Leicester, UK; National Institute for Health and Care Research Leicester Biomedical Research Centre, Leicester, UK.
| |
Collapse
|
3
|
Chen M, Baron V, Hammarström B, Hammond RJH, Glynne-Jones P, Gillespie SH, Dholakia K. Monitoring Live Mycobacteria in Real-Time Using a Microfluidic Acoustic-Raman Platform. Methods Mol Biol 2024; 2833:109-119. [PMID: 38949705 DOI: 10.1007/978-1-0716-3981-8_11] [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] [Indexed: 07/02/2024]
Abstract
Tuberculosis (TB) is the most common cause of death from an infectious disease. Although treatment has been available for more than 70 years, it still takes too long and many patients default risking relapse and the emergence of resistance. It is known that lipid-rich, phenotypically antibiotic-tolerant, bacteria are more resistant to antibiotics and may be responsible for relapse necessitating extended therapy. Using a microfluidic system that acoustically traps live mycobacteria, M. smegmatis, a model organism for M. tuberculosis we can perform optical analysis in the form of wavelength-modulated Raman spectroscopy (WMRS) on the trapped organisms. This system can allow observations of the mycobacteria for up to 8 h. By adding antibiotics, it is possible to study the effect of antibiotics in real-time by comparing the Raman fingerprints in comparison to the unstressed condition. This microfluidic platform may be used to study any microorganism and to dynamically monitor its response to many conditions including antibiotic stress, and changes in the growth media. This opens the possibility of understanding better the stimuli that trigger the lipid-rich downregulated and phenotypically antibiotic-resistant cell state.
Collapse
Affiliation(s)
- Mingzhou Chen
- School of Physics, University of St Andrews, St Andrews, UK
| | - Vincent Baron
- Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, UK
| | | | - Robert J H Hammond
- Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, UK
| | - Peter Glynne-Jones
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Stephen H Gillespie
- Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, UK
| | - Kishan Dholakia
- School of Physics, University of St Andrews, St Andrews, UK.
- Centre of Light for Life, University of Adelaide, Adelaide, SA, Australia.
| |
Collapse
|
4
|
Dargham T, Mallick I, Kremer L, Santucci P, Canaan S. Intrabacterial lipid inclusion-associated proteins: a core machinery conserved from saprophyte Actinobacteria to the human pathogen Mycobacterium tuberculosis. FEBS Open Bio 2023; 13:2306-2323. [PMID: 37872001 PMCID: PMC10699116 DOI: 10.1002/2211-5463.13721] [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: 09/05/2023] [Revised: 10/02/2023] [Accepted: 10/19/2023] [Indexed: 10/25/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the aetiologic agent of tuberculosis (TB), stores triacylglycerol (TAG) in the form of intrabacterial lipid inclusions (ILI) to survive and chronically persist within its host. These highly energetic molecules represent a major source of carbon to support bacterial persistence and reactivation, thus playing a leading role in TB pathogenesis. However, despite its physiological and clinical relevance, ILI metabolism in Mtb remains poorly understood. Recent discoveries have suggested that several ILI-associated proteins might be widely conserved across TAG-producing prokaryotes, but still very little is known regarding the nature and the biological functions of these proteins. Herein, we performed an in silico analysis of three independent ILI-associated proteomes previously reported to computationally define a potential core ILI-associated proteome, referred to as ILIome. Our investigation revealed the presence of 70 orthologous proteins that were strictly conserved, thereby defining a minimal ILIome core. We further narrowed our analysis to proteins involved in lipid metabolism and discuss here their putative biological functions, along with their molecular interactions and dynamics at the surface of these bacterial organelles. We also highlight the experimental limitations of the original proteomic investigations and of the present bioinformatic analysis, while describing new technological approaches and presenting biological perspectives in the field. The in silico investigation presented here aims at providing useful datasets that could constitute a scientific resource of broad interest for the mycobacterial community, with the ultimate goal of enlightening ILI metabolism in prokaryotes with a special emphasis on Mtb pathogenesis.
Collapse
Affiliation(s)
- Tonia Dargham
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
- IHU Méditerranée InfectionAix‐Marseille Univ.France
| | - Ivy Mallick
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
| | - Laurent Kremer
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM)Université de MontpellierFrance
- INSERM, Institut de Recherche en Infectiologie de MontpellierFrance
| | - Pierre Santucci
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
| | - Stéphane Canaan
- Aix‐Marseille Univ, CNRS, LISM UMR 7255, IMM FR3479, IM2BFrance
| |
Collapse
|
5
|
Zachariou M, Arandjelović O, Dombay E, Sabiiti W, Mtafya B, Ntinginya NE, Sloan DJ. Localization and phenotyping of tuberculosis bacteria using a combination of deep learning and SVMs. Comput Biol Med 2023; 167:107573. [PMID: 37913616 DOI: 10.1016/j.compbiomed.2023.107573] [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: 06/07/2023] [Revised: 09/09/2023] [Accepted: 10/11/2023] [Indexed: 11/03/2023]
Abstract
Successful treatment of pulmonary tuberculosis (TB) depends on early diagnosis and careful monitoring of treatment response. Identification of acid-fast bacilli by fluorescence microscopy of sputum smears is a common tool for both tasks. Microscopy-based analysis of the intracellular lipid content and dimensions of individual Mycobacterium tuberculosis (Mtb) cells also describe phenotypic changes which may improve our biological understanding of antibiotic therapy for TB. However, fluorescence microscopy is a challenging, time-consuming and subjective procedure. In this work, we automate examination of fields of view (FOVs) from microscopy images to determine the lipid content and dimensions (length and width) of Mtb cells. We introduce an adapted variation of the UNet model to efficiently localising bacteria within FOVs stained by two fluorescence dyes; auramine O to identify Mtb and LipidTox Red to identify intracellular lipids. Thereafter, we propose a feature extractor in conjunction with feature descriptors to extract a representation into a support vector multi-regressor and estimate the length and width of each bacterium. Using a real-world data corpus from Tanzania, the proposed method i) outperformed previous methods for bacterial detection with a 8% improvement (Dice coefficient) and ii) estimated the cell length and width with a root mean square error of less than 0.01%. Our network can be used to examine phenotypic characteristics of Mtb cells visualised by fluorescence microscopy, improving consistency and time efficiency of this procedure compared to manual methods.
Collapse
Affiliation(s)
- Marios Zachariou
- School of Computer Science, University of St Andrews, St Andrews, KY16 9SX, United Kingdom.
| | - Ognjen Arandjelović
- School of Computer Science, University of St Andrews, St Andrews, KY16 9SX, United Kingdom
| | - Evelin Dombay
- School of Medicine, University of St Andrews, St Andrews, KY16 9AJ, United Kingdom
| | - Wilber Sabiiti
- School of Medicine, University of St Andrews, St Andrews, KY16 9AJ, United Kingdom
| | | | | | - Derek J Sloan
- School of Medicine, University of St Andrews, St Andrews, KY16 9AJ, United Kingdom
| |
Collapse
|
6
|
Kim H, Shin SJ. Revolutionizing control strategies against Mycobacterium tuberculosis infection through selected targeting of lipid metabolism. Cell Mol Life Sci 2023; 80:291. [PMID: 37704889 PMCID: PMC11072447 DOI: 10.1007/s00018-023-04914-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 04/12/2023] [Accepted: 08/07/2023] [Indexed: 09/15/2023]
Abstract
Lipid species play a critical role in the growth and virulence expression of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). During Mtb infection, foamy macrophages accumulate lipids in granulomas, providing metabolic adaptation and survival strategies for Mtb against multiple stresses. Host-derived lipid species, including triacylglycerol and cholesterol, can also contribute to the development of drug-tolerant Mtb, leading to reduced efficacy of antibiotics targeting the bacterial cell wall or transcription. Transcriptional and metabolic analyses indicate that lipid metabolism-associated factors of Mtb are highly regulated by antibiotics and ultimately affect treatment outcomes. Despite the well-known association between major antibiotics and lipid metabolites in TB treatment, a comprehensive understanding of how altered lipid metabolites in both host and Mtb influence treatment outcomes in a drug-specific manner is necessary to overcome drug tolerance. The current review explores the controversies and correlations between lipids and drug efficacy in various Mtb infection models and proposes novel approaches to enhance the efficacy of anti-TB drugs. Moreover, the review provides insights into the efficacious control of Mtb infection by elucidating the impact of lipids on drug efficacy. This review aims to improve the effectiveness of current anti-TB drugs and facilitate the development of innovative therapeutic strategies against Mtb infection by making reverse use of Mtb-favoring lipid species.
Collapse
Affiliation(s)
- Hagyu Kim
- Department of Microbiology, Institute for Immunology and Immunological Disease, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea
| | - Sung Jae Shin
- Department of Microbiology, Institute for Immunology and Immunological Disease, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea.
| |
Collapse
|
7
|
Farzand R, Haigh RD, Monk P, Haldar P, Patel H, Pareek M, Verma R, Barer MR, Woltmann G, Ahyow L, Jagatia H, Decker J, Mukamolova GV, Cooper AM, Garton NJ, O’Hare HM. A Persistent Tuberculosis Outbreak in the UK Is Characterized by Hydrophobic fadB4-Deficient Mycobacterium tuberculosis That Replicates Rapidly in Macrophages. mBio 2022; 13:e0265622. [PMID: 36374090 PMCID: PMC9765663 DOI: 10.1128/mbio.02656-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The genetic diversity of Mycobacterium tuberculosis can influence disease severity and transmissibility. To better understand how this diversity influences individuals and communities, we phenotyped M. tuberculosis that was causing a persistent outbreak in the East Midlands, United Kingdom. Compared to nonoutbreak isolates, bacilli had higher lipid contents and more hydrophobic cell surfaces. In macrophage infection models, the bacteria increased more rapidly, provoked the enhanced accumulation of macrophage lipid droplets and enhanced the secretion of IL-1β. Natural deletions in fadB4, nrdB, and plcC distinguished the outbreak isolates from other lineage 3 isolates in the region. fadB4 is annotated with a putative role in cell envelope biosynthesis, so the loss of this gene has the potential to alter the interactions of bacteria with immune cells. Reintroduction of fadB4 to the outbreak strain led to a phenotype that more closely resembled those of nonoutbreak strains. The improved understanding of the microbiological characteristics and the corresponding genetic polymorphisms that associate with outbreaks have the potential to inform tuberculosis control. IMPORTANCE Tuberculosis (TB) killed 1.5 million people in 2020 and affects every country. The extent to which the natural genetic diversity of Mycobacterium tuberculosis influences disease manifestation at both the individual and epidemiological levels remains poorly understood. Insights into how pathogen polymorphisms affect patterns of TB have the potential to translate into clinical and public health practice. Two distinct lineage 3 strains isolated from local TB outbreaks, one of which (CH) was rapidly terminated and the other of which (Lro) persistently transmitted for over a decade, provided us with an opportunity to study these issues. We compared genome sequences, microbiological characteristics, and early immune responses that were evoked upon infection. Our results indicate that the natural lack of fadB4 in the Lro strain contributes to its unique features.
Collapse
Affiliation(s)
- Robeena Farzand
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Richard D. Haigh
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Philip Monk
- Public Health England, Department of Health and Social Care in England, Government Agency, East Midlands, UK
| | - Pranabashis Haldar
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Hemu Patel
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
- University Hospitals Leicester NHS Trust, University of Leicestergrid.9918.9, Leicester, UK
| | - Manish Pareek
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
- University Hospitals Leicester NHS Trust, University of Leicestergrid.9918.9, Leicester, UK
| | - Raman Verma
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
- University Hospitals Leicester NHS Trust, University of Leicestergrid.9918.9, Leicester, UK
| | - Michael R. Barer
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Gerrit Woltmann
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
- University Hospitals Leicester NHS Trust, University of Leicestergrid.9918.9, Leicester, UK
| | - Lauren Ahyow
- National TB Unit, UK Health Security Agency, Government Agency, London, UK
| | - Heena Jagatia
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Jonathan Decker
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Galina V. Mukamolova
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Andrea M. Cooper
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Natalie J. Garton
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| | - Helen M. O’Hare
- Leicester TB Research Group, Department of Respiratory Sciences, University of Leicestergrid.9918.9, Leicester, UK
| |
Collapse
|
8
|
Parbhoo T, Mouton JM, Sampson SL. Phenotypic adaptation of Mycobacterium tuberculosis to host-associated stressors that induce persister formation. Front Cell Infect Microbiol 2022; 12:956607. [PMID: 36237425 PMCID: PMC9551238 DOI: 10.3389/fcimb.2022.956607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/24/2022] [Indexed: 11/29/2022] Open
Abstract
Mycobacterium tuberculosis exhibits a remarkable ability to interfere with the host antimicrobial response. The pathogen exploits elaborate strategies to cope with diverse host-induced stressors by modulating its metabolism and physiological state to prolong survival and promote persistence in host tissues. Elucidating the adaptive strategies that M. tuberculosis employs during infection to enhance persistence is crucial to understanding how varying physiological states may differentially drive disease progression for effective management of these populations. To improve our understanding of the phenotypic adaptation of M. tuberculosis, we review the adaptive strategies employed by M. tuberculosis to sense and coordinate a physiological response following exposure to various host-associated stressors. We further highlight the use of animal models that can be exploited to replicate and investigate different aspects of the human response to infection, to elucidate the impact of the host environment and bacterial adaptive strategies contributing to the recalcitrance of infection.
Collapse
|
9
|
Liebenberg D, Gordhan BG, Kana BD. Drug resistant tuberculosis: Implications for transmission, diagnosis, and disease management. Front Cell Infect Microbiol 2022; 12:943545. [PMID: 36211964 PMCID: PMC9538507 DOI: 10.3389/fcimb.2022.943545] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 09/06/2022] [Indexed: 01/17/2023] Open
Abstract
Drug resistant tuberculosis contributes significantly to the global burden of antimicrobial resistance, often consuming a large proportion of the healthcare budget and associated resources in many endemic countries. The rapid emergence of resistance to newer tuberculosis therapies signals the need to ensure appropriate antibiotic stewardship, together with a concerted drive to develop new regimens that are active against currently circulating drug resistant strains. Herein, we highlight that the current burden of drug resistant tuberculosis is driven by a combination of ongoing transmission and the intra-patient evolution of resistance through several mechanisms. Global control of tuberculosis will require interventions that effectively address these and related aspects. Interrupting tuberculosis transmission is dependent on the availability of novel rapid diagnostics which provide accurate results, as near-patient as is possible, together with appropriate linkage to care. Contact tracing, longitudinal follow-up for symptoms and active mapping of social contacts are essential elements to curb further community-wide spread of drug resistant strains. Appropriate prophylaxis for contacts of drug resistant index cases is imperative to limit disease progression and subsequent transmission. Preventing the evolution of drug resistant strains will require the development of shorter regimens that rapidly eliminate all populations of mycobacteria, whilst concurrently limiting bacterial metabolic processes that drive drug tolerance, mutagenesis and the ultimate emergence of resistance. Drug discovery programs that specifically target bacterial genetic determinants associated with these processes will be paramount to tuberculosis eradication. In addition, the development of appropriate clinical endpoints that quantify drug tolerant organisms in sputum, such as differentially culturable/detectable tubercle bacteria is necessary to accurately assess the potential of new therapies to effectively shorten treatment duration. When combined, this holistic approach to addressing the critical problems associated with drug resistance will support delivery of quality care to patients suffering from tuberculosis and bolster efforts to eradicate this disease.
Collapse
|
10
|
Tuberculosis Bacteria Detection and Counting in Fluorescence Microscopy Images Using a Multi-Stage Deep Learning Pipeline. INFORMATION 2022. [DOI: 10.3390/info13020096] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The manual observation of sputum smears by fluorescence microscopy for the diagnosis and treatment monitoring of patients with tuberculosis (TB) is a laborious and subjective task. In this work, we introduce an automatic pipeline which employs a novel deep learning-based approach to rapidly detect Mycobacterium tuberculosis (Mtb) organisms in sputum samples and thus quantify the burden of the disease. Fluorescence microscopy images are used as input in a series of networks, which ultimately produces a final count of present bacteria more quickly and consistently than manual analysis by healthcare workers. The pipeline consists of four stages: annotation by cycle-consistent generative adversarial networks (GANs), extraction of salient image patches, classification of the extracted patches, and finally, regression to yield the final bacteria count. We empirically evaluate the individual stages of the pipeline as well as perform a unified evaluation on previously unseen data that were given ground-truth labels by an experienced microscopist. We show that with no human intervention, the pipeline can provide the bacterial count for a sample of images with an error of less than 5%.
Collapse
|
11
|
Shivakoti R, Newman JW, Hanna LE, Queiroz ATL, Borkowski K, Gupte AN, Paradkar M, Satyamurthi P, Kulkarni V, Selva M, Pradhan N, Shivakumar SVBY, Natarajan S, Karunaianantham R, Gupte N, Thiruvengadam K, Fiehn O, Bharadwaj R, Kagal A, Gaikwad S, Sangle S, Golub JE, Andrade BB, Mave V, Gupta A, Padmapriyadarsini C. Host lipidome and tuberculosis treatment failure. Eur Respir J 2022; 59:2004532. [PMID: 34375300 PMCID: PMC9625841 DOI: 10.1183/13993003.04532-2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/24/2021] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Host lipids play important roles in tuberculosis (TB) pathogenesis. Whether host lipids at TB treatment initiation (baseline) affect subsequent treatment outcomes has not been well characterised. We used unbiased lipidomics to study the prospective association of host lipids with TB treatment failure. METHODS A case-control study (n=192), nested within a prospective cohort study, was used to investigate the association of baseline plasma lipids with TB treatment failure among adults with pulmonary TB. Cases (n=46) were defined as TB treatment failure, while controls (n=146) were those without failure. Complex lipids and inflammatory lipid mediators were measured using liquid chromatography mass spectrometry techniques. Adjusted least-square regression was used to assess differences in groups. In addition, machine learning identified lipids with highest area under the curve (AUC) to classify cases and controls. RESULTS Baseline levels of 32 lipids differed between controls and those with treatment failure after false discovery rate adjustment. Treatment failure was associated with lower baseline levels of cholesteryl esters and oxylipin, and higher baseline levels of ceramides and triglycerides compared to controls. Two cholesteryl ester lipids combined in a unique classifier model provided an AUC of 0.79 (95% CI 0.65-0.93) in the test dataset for prediction of TB treatment failure. CONCLUSIONS We identified lipids, some with known roles in TB pathogenesis, associated with TB treatment failure. In addition, a lipid signature with prognostic accuracy for TB treatment failure was identified. These lipids could be potential targets for risk-stratification, adjunct therapy and treatment monitoring.
Collapse
Affiliation(s)
- Rupak Shivakoti
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Dept of Epidemiology, Columbia University Mailman School of Public Health, New York, NY, USA
| | - John W Newman
- Obesity and Metabolism Research Unit, Western Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Davis, CA, USA
- Dept of Nutrition, University of California, Davis, CA, USA
- West Coast Metabolomics Center, University of California, Davis, CA, USA
| | | | - Artur T L Queiroz
- Instituto Goncalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
- Multinational Organization Network Sponsoring Translational and Epidemiological Research, Salvador, Brazil
| | - Kamil Borkowski
- West Coast Metabolomics Center, University of California, Davis, CA, USA
| | - Akshay N Gupte
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mandar Paradkar
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | | | - Vandana Kulkarni
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - Murugesh Selva
- National Institute for Research in Tuberculosis, Chennai, India
| | - Neeta Pradhan
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | | | | | | | - Nikhil Gupte
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | | | - Oliver Fiehn
- West Coast Metabolomics Center, University of California, Davis, CA, USA
| | - Renu Bharadwaj
- Byramjee-Jeejeebhoy Government Medical College, Pune, India
| | - Anju Kagal
- Byramjee-Jeejeebhoy Government Medical College, Pune, India
| | - Sanjay Gaikwad
- Byramjee-Jeejeebhoy Government Medical College, Pune, India
| | | | - Jonathan E Golub
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bruno B Andrade
- Instituto Goncalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
- Multinational Organization Network Sponsoring Translational and Epidemiological Research, Salvador, Brazil
- Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Brazil
- Curso de Medicina, Faculdade de Tecnologia e Ciências, Salvador, Brazil
- Curso de Medicina, Universidade Salvador (UNIFACS), Laureate International Universities, Salvador, Brazil
- Escola Bahiana de Medicina e Saúde Pública (EBMSP), Salvador, Brazil
| | - Vidya Mave
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - Amita Gupta
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
- Equal contribution
| | | |
Collapse
|
12
|
McCallum AD, Pertinez HE, Else LJ, Dilly-Penchala S, Chirambo AP, Sheha I, Chasweka M, Chitani A, Malamba RD, Meghji JZ, Gordon SB, Davies GR, Khoo SH, Sloan DJ, Mwandumba HC. Intrapulmonary Pharmacokinetics of First-line Anti-tuberculosis Drugs in Malawian Patients With Tuberculosis. Clin Infect Dis 2021; 73:e3365-e3373. [PMID: 32856694 PMCID: PMC8563277 DOI: 10.1093/cid/ciaa1265] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Further work is required to understand the intrapulmonary pharmacokinetics of first-line anti-tuberculosis drugs. This study aimed to describe the plasma and intrapulmonary pharmacokinetics of rifampicin, isoniazid, pyrazinamide, and ethambutol, and explore relationships with clinical treatment outcomes in patients with pulmonary tuberculosis. METHODS Malawian adults with a first presentation of microbiologically confirmed pulmonary tuberculosis received standard 6-month first-line therapy. Plasma and intrapulmonary samples were collected 8 and 16 weeks into treatment and drug concentrations measured in plasma, lung/airway epithelial lining fluid (ELF), and alveolar cells. Population pharmacokinetic modeling generated estimates of drug exposure (Cmax and AUC) from individual-level post hoc Bayesian estimates of plasma and intrapulmonary pharmacokinetics. RESULTS One-hundred fifty-seven patients (58% HIV coinfected) participated. Despite standard weight-based dosing, peak plasma concentrations of first-line drugs were below therapeutic drug-monitoring targets. Rifampicin concentrations were low in all 3 compartments. Isoniazid, pyrazinamide, and ethambutol achieved higher concentrations in ELF and alveolar cells than plasma. Isoniazid and pyrazinamide concentrations were 14.6-fold (95% CI, 11.2-18.0-fold) and 49.8-fold (95% CI, 34.2-65.3-fold) higher in ELF than plasma, respectively. Ethambutol concentrations were highest in alveolar cells (alveolar cell-plasma ratio, 15.0; 95% CI, 11.4-18.6). Plasma or intrapulmonary pharmacokinetics did not predict clinical treatment response. CONCLUSIONS We report differential drug concentrations between plasma and the lung. While plasma concentrations were below therapeutic monitoring targets, accumulation of drugs at the site of disease may explain the success of the first-line regimen. The low rifampicin concentrations observed in all compartments lend strong support for ongoing clinical trials of high-dose rifampicin regimens.
Collapse
Affiliation(s)
- Andrew D McCallum
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Henry E Pertinez
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Laura J Else
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Sujan Dilly-Penchala
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Aaron P Chirambo
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | - Irene Sheha
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | - Madalitso Chasweka
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | - Alex Chitani
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | - Rose D Malamba
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | - Jamilah Z Meghji
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Stephen B Gordon
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Geraint R Davies
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Saye H Khoo
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Derek J Sloan
- School of Medicine, University of St Andrews, St Andrews, United Kingdom
| | - Henry C Mwandumba
- Malawi-Liverpool-Wellcome Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| |
Collapse
|
13
|
Mekonnen D, Derbie A, Mihret A, Yimer SA, Tønjum T, Gelaw B, Nibret E, Munshae A, Waddell SJ, Aseffa A. Lipid droplets and the transcriptome of Mycobacterium tuberculosis from direct sputa: a literature review. Lipids Health Dis 2021; 20:129. [PMID: 34602073 PMCID: PMC8487580 DOI: 10.1186/s12944-021-01550-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/09/2021] [Indexed: 11/21/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the main etiology of tuberculosis (TB), is predominantly an intracellular pathogen that has caused infection, disease and death in humans for centuries. Lipid droplets (LDs) are dynamic intracellular organelles that are found across the evolutionary tree of life. This review is an evaluation of the current state of knowledge regarding Mtb-LD formation and associated Mtb transcriptome directly from sputa.Based on the LD content, Mtb in sputum may be classified into three groups: LD positive, LD negative and LD borderline. However, the clinical and evolutionary importance of each state is not well elaborated. Mounting evidence supports the view that the presence of LD positive Mtb bacilli in sputum is a biomarker of slow growth, low energy state, towards lipid degradation, and drug tolerance. In Mtb, LD may serve as a source of chemical energy, scavenger of toxic compounds, prevent destruction of Mtb through autophagy, delay trafficking of lysosomes towards the phagosome, and contribute to Mtb persistence. It is suggest that LD is a key player in the induction of a spectrum of phenotypic and metabolic states of Mtb in the macrophage, granuloma and extracellular sputum microenvironment. Tuberculosis patients with high proportion of LD positive Mtb in pretreatment sputum was associated with higher rate of poor treatment outcome, indicating that LD may have a clinical application in predicting treatment outcome.The propensity for LD formation among Mtb lineages is largely unknown. The role of LD on Mtb transmission and disease phenotype (pulmonary TB vs extra-pulmonary TB) is not well understood. Thus, further studies are needed to understand the relationships between LD positivity and Mtb lineage, Mtb transmission and clinical types.
Collapse
Affiliation(s)
- Daniel Mekonnen
- Department of Medical Microbiology, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia.
| | - Awoke Derbie
- Department of Medical Microbiology, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- The Centre for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), Addis Ababa University, Addis Ababa, Ethiopia
| | - Adane Mihret
- Armauer Hansen Research Institute, Jimma Road, ALERT Compound, PO Box 1005, Addis Ababa, Ethiopia
- Department of Medical Microbiology, Immunology and Parasitology, College of Medicine and Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Solomon Abebe Yimer
- Department of Microbiology, University of Oslo, PO Box 1071, Blindern, NO-0316, Oslo, Norway
- Coalition for Epidemic Preparedness Innovations, CEPI, P.O. Box 123, Torshov, 0412, Oslo, Norway
| | - Tone Tønjum
- Department of Microbiology, University of Oslo, PO Box 1071, Blindern, NO-0316, Oslo, Norway
- Department of Microbiology, Oslo University Hospital, PO Box 4950, Nydalen, NO-0424, Oslo, Norway
| | - Baye Gelaw
- Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Endalkachew Nibret
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia
| | - Abaineh Munshae
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia
| | - Simon J Waddell
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, BN1 9PX, UK
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Jimma Road, ALERT Compound, PO Box 1005, Addis Ababa, Ethiopia
| |
Collapse
|
14
|
Muliaditan M, Della Pasqua O. Bacterial growth dynamics and pharmacokinetic-pharmacodynamic relationships of rifampicin and bedaquiline in BALB/c mice. Br J Pharmacol 2021; 179:1251-1263. [PMID: 34599506 PMCID: PMC9303191 DOI: 10.1111/bph.15688] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 08/07/2021] [Accepted: 09/01/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Translational efforts in the evaluation of novel anti-tubercular drugs demand better integration of pharmacokinetic-pharmacodynamic data arising from preclinical protocols. However, parametric approaches that discriminate drug effect from the underlying bacterial growth dynamics have not been fully explored, making it difficult to translate and/or extrapolate preclinical findings to humans. This analysis aims to develop a drug-disease model that allows distinction between drug- and system-specific properties. EXPERIMENTAL APPROACH Given their clinical relevance, rifampicin and bedaquiline were used as test compounds. A two-state model was used to describe bacterial growth dynamics. The approach assumes the existence of fast- and slow-growing bacterial populations. Drug effect on the growth dynamics of each subpopulation was characterised in terms of potency (EC50 -F and EC50 -S) and maximum killing rate. KEY RESULTS The doubling time of the fast- and slow-growing population was estimated to be 25 h and 42 days, respectively. Rifampicin was more potent against the fast-growing (EC50 -F = 4.8 mg·L-1 ), as compared with the slow-growing population (EC50 -S = 60.2 mg·L-1 ). Bedaquiline showed higher potency than rifampicin (EC50 -F = 0.19 mg·L-1 ; EC50 -S = 3.04 mg·L-1 ). External validation procedures revealed an effect of infection route on the apparent potency of rifampicin. CONCLUSION AND IMPLICATIONS Model parameter estimates suggest that nearly maximum killing rate is achieved against fast-growing, but not against slow-growing populations at the tested doses. Evidence of differences in drug potency for each subpopulation may facilitate the translation of preclinical findings and improve the dose rationale for anti-tubercular drugs in humans.
Collapse
Affiliation(s)
- Morris Muliaditan
- Clinical Pharmacology & Therapeutics Group, School of Life and Medical Sciences, University College London, London, UK
| | - Oscar Della Pasqua
- Clinical Pharmacology & Therapeutics Group, School of Life and Medical Sciences, University College London, London, UK.,Clinical Pharmacology, Modelling and Simulation, GlaxoSmithKline, Brentford, UK
| |
Collapse
|
15
|
Srivastava S, Deshpande D, Magombedze G, van Zyl J, Cirrincione K, Martin K, Bendet P, Berg A, Hanna D, Romero K, Hermann D, Gumbo T. Duration of pretomanid/moxifloxacin/pyrazinamide therapy compared with standard therapy based on time-to-extinction mathematics. J Antimicrob Chemother 2021; 75:392-399. [PMID: 31713607 PMCID: PMC6966096 DOI: 10.1093/jac/dkz460] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/29/2019] [Accepted: 10/08/2019] [Indexed: 01/13/2023] Open
Abstract
Objectives Animal models have suggested that the combination of pretomanid with pyrazinamide and moxifloxacin (PaMZ) may shorten TB therapy duration to 3–4 months. Here, we tested that in the hollow-fibre system model of TB (HFS-TB). Methods A series of HFS-TB experiments were performed to compare the kill rates of the PaMZ regimen with the standard three-drug combination therapy. HFS-TB experiments were performed with bacilli in log-phase growth treated for 28 days, intracellular bacilli treated daily for 28 days and semi-dormant Mycobacterium tuberculosis treated with daily therapy for 56 days for sterilizing effect. Next, time-to-extinction equations were employed, followed by morphism transformation and Latin hypercube sampling, to determine the proportion of patients who achieved a time to extinction of 3, 4 or 6 months with each regimen. Results Using linear regression, the HFS-TB sterilizing effect rates of the PaMZ regimen versus the standard-therapy regimen during the 56 days were 0.18 (95% credible interval=0.13–0.23) versus 0.15 (95% credible interval=0.08–0.21) log10 cfu/mL/day, compared with 0.16 (95% credible interval=0.13–0.18) versus 0.11 (95% credible interval=0.09–0.13) log10 cfu/mL/day in the Phase II clinical trial, respectively. Using time-to-extinction and Latin hypercube sampling modelling, the expected percentages of patients in which the PaMZ regimen would achieve sterilization were 40.37% (95% credible interval=39.1–41.34) and 72.30% (95% credible interval=71.41–73.17) at 3 and 4 months duration of therapy, respectively, versus 93.67% (95% credible interval=93.18–94.13) at 6 months for standard therapy. Conclusions The kill rates of the PaMZ regimen were predicted to be insufficient to achieve cure in less than 6 months in most patients.
Collapse
Affiliation(s)
- Shashikant Srivastava
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Devyani Deshpande
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Gesham Magombedze
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Johanna van Zyl
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Kayle Cirrincione
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | | | | | - Alexander Berg
- Critical Path to TB Drug Regimens, Critical Path Institute, Tucson, AZ, USA
| | - Debra Hanna
- Critical Path to TB Drug Regimens, Critical Path Institute, Tucson, AZ, USA.,Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Klaus Romero
- Critical Path to TB Drug Regimens, Critical Path Institute, Tucson, AZ, USA
| | - Dave Hermann
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA.,Praedicare Laboratories, Dallas, TX, USA.,Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town, Cape Town, South Africa
| |
Collapse
|
16
|
Bacterial load slopes represent biomarkers of tuberculosis therapy success, failure, and relapse. Commun Biol 2021; 4:664. [PMID: 34079045 PMCID: PMC8172544 DOI: 10.1038/s42003-021-02184-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 05/03/2021] [Indexed: 02/04/2023] Open
Abstract
There is an urgent need to discover biomarkers that are predictive of long-term TB treatment outcomes, since treatment is expense and prolonged to document relapse. We used mathematical modeling and machine learning to characterize a predictive biomarker for TB treatment outcomes. We computed bacterial kill rates, γf for fast- and γs for slow/non-replicating bacteria, using patient sputum data to determine treatment duration by computing time-to-extinction of all bacterial subpopulations. We then derived a γs-slope-based rule using first 8 weeks sputum data, that demonstrated a sensitivity of 92% and a specificity of 89% at predicting relapse-free cure for 2, 3, 4, and 6 months TB regimens. In comparison, current methods (two-month sputum culture conversion and the Extended-EBA) methods performed poorly, with sensitivities less than 34%. These biomarkers will accelerate evaluation of novel TB regimens, aid better clinical trial designs and will allow personalization of therapy duration in routine treatment programs.
Collapse
|
17
|
Ndhlovu V, Kiran A, Sloan DJ, Mandala W, Nliwasa M, Everett DB, Kumwenda B, Mwapasa M, Kontogianni K, Kamdolozi M, Corbett E, Caws M, Davies G. Characterization of DNA methylation in Malawian Mycobacterium tuberculosis clinical isolates. PeerJ 2020; 8:e10432. [PMID: 33362962 PMCID: PMC7749660 DOI: 10.7717/peerj.10432] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/05/2020] [Indexed: 11/23/2022] Open
Abstract
Background Although Mycobacterium tuberculosis (Mtb) strains exhibit genomic homology of >99%, there is considerable variation in the phenotype. The underlying mechanisms of phenotypic heterogeneity in Mtb are not well understood but epigenetic variation is thought to contribute. At present the methylome of Mtb has not been completely characterized. Methods We completed methylomes of 18 Mycobacterium tuberculosis (Mtb) clinical isolates from Malawi representing the largest number of Mtb genomes to be completed in a single study using Single Molecule Real Time (SMRT) sequencing to date. Results We replicate and confirm four methylation disrupting mutations in 4 lineages of Mtb. For the first time we report complete loss of methylation courtesy of C758T (S253L) mutation in the MamB gene of Indo-oceanic lineage of Mtb. Additionally, we report a novel missense mutation G454A (G152S) in the MamA gene of the Euro-American lineage which could potentially be attributed to total disruption of methylation in the CCCAG motif but partial loss in a partner motif. Through a genomic and methylome comparative analysis with a global sample of sixteen, we report previously unknown mutations affecting the pks15/1 locus in L6 isolates. We confirm that methylation in Mtb is lineage specific although some unresolved issues still remain.
Collapse
Affiliation(s)
- Victor Ndhlovu
- University of Malawi, College of Medicine, Blantyre, Malawi
- University of Liverpool, Liverpool, United Kingdom
- Helse Nord Tuberculosis Initiative Project, University of Malawi, College of Medicine, Blantyre, Malawi
| | - Anmol Kiran
- Malawi-Liverpool Welcome Trust, Blantyre, Malawi
- University of Edinburgh, Edinburgh, United Kingdom
| | - Derek J. Sloan
- Department of Medicine, University of St. Andrews, St. Andrews, United Kingdom
| | - Wilson Mandala
- Malawi-Liverpool Welcome Trust, Blantyre, Malawi
- Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo, Malawi
| | - Marriott Nliwasa
- University of Malawi, College of Medicine, Blantyre, Malawi
- Helse Nord Tuberculosis Initiative Project, University of Malawi, College of Medicine, Blantyre, Malawi
| | - Dean B. Everett
- Malawi-Liverpool Welcome Trust, Blantyre, Malawi
- University of Edinburgh, Edinburgh, United Kingdom
| | | | - Mphatso Mwapasa
- Helse Nord Tuberculosis Initiative Project, University of Malawi, College of Medicine, Blantyre, Malawi
| | | | | | - Elizabeth Corbett
- Helse Nord Tuberculosis Initiative Project, University of Malawi, College of Medicine, Blantyre, Malawi
- Malawi-Liverpool Welcome Trust, Blantyre, Malawi
- London School of Hygiene & Tropical Medicine, University of London, London, United Kingdom
| | - Maxine Caws
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Birat Nepal Medical Trust, Lazimpat, Kathmandu, Kathmandu, Nepal
| | - Gerry Davies
- University of Liverpool, Liverpool, United Kingdom
- Malawi-Liverpool Welcome Trust, Blantyre, Malawi
| |
Collapse
|
18
|
Theron G, Limberis J, Venter R, Smith L, Pietersen E, Esmail A, Calligaro G, Te Riele J, de Kock M, van Helden P, Gumbo T, Clark TG, Fennelly K, Warren R, Dheda K. Bacterial and host determinants of cough aerosol culture positivity in patients with drug-resistant versus drug-susceptible tuberculosis. Nat Med 2020; 26:1435-1443. [PMID: 32601338 PMCID: PMC8353872 DOI: 10.1038/s41591-020-0940-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 05/13/2020] [Indexed: 12/27/2022]
Abstract
A burgeoning epidemic of drug-resistant tuberculosis (TB) threatens to derail global control efforts. Although the mechanisms remain poorly clarified, drug-resistant strains are widely believed to be less infectious than drug-susceptible strains. Consequently, we hypothesized that lower proportions of patients with drug-resistant TB would have culturable Mycobacterium tuberculosis from respirable, cough-generated aerosols compared to patients with drug-susceptible TB, and that multiple factors, including mycobacterial genomic variation, would predict culturable cough aerosol production. We enumerated the colony forming units in aerosols (≤10 µm) from 452 patients with TB (227 with drug resistance), compared clinical characteristics, and performed mycobacterial whole-genome sequencing, dormancy phenotyping and drug-susceptibility analyses on M. tuberculosis from sputum. After considering treatment duration, we found that almost half of the patients with drug-resistant TB were cough aerosol culture-positive. Surprisingly, neither mycobacterial genomic variants, lineage, nor dormancy status predicted cough aerosol culture positivity. However, mycobacterial sputum bacillary load and clinical characteristics, including a lower symptom score and stronger cough, were strongly predictive, thereby supporting targeted transmission-limiting interventions. Effective treatment largely abrogated cough aerosol culture positivity; however, this was not always rapid. These data question current paradigms, inform public health strategies and suggest the need to redirect TB transmission-associated research efforts toward host-pathogen interactions.
Collapse
Affiliation(s)
- Grant Theron
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Jason Limberis
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
| | - Rouxjeane Venter
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Liezel Smith
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Elize Pietersen
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
| | - Aliasgar Esmail
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
| | - Greg Calligaro
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
| | | | - Marianna de Kock
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Paul van Helden
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor University Medical Center, Dallas, TX, USA
| | - Taane G Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Kevin Fennelly
- Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Robin Warren
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Keertan Dheda
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa.
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| |
Collapse
|
19
|
Kloprogge F, Mwandumba HC, Banda G, Kamdolozi M, Shani D, Corbett EL, Kontogianni N, Ward S, Khoo SH, Davies GR, Sloan DJ. Longitudinal Pharmacokinetic-Pharmacodynamic Biomarkers Correlate With Treatment Outcome in Drug-Sensitive Pulmonary Tuberculosis: A Population Pharmacokinetic-Pharmacodynamic Analysis. Open Forum Infect Dis 2020; 7:ofaa218. [PMID: 32733976 PMCID: PMC7378673 DOI: 10.1093/ofid/ofaa218] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/03/2020] [Indexed: 11/13/2022] Open
Abstract
Background This study aims to explore relationships between baseline demographic covariates, plasma antibiotic exposure, sputum bacillary load, and clinical outcome data to help improve future tuberculosis (TB) treatment response predictions. Methods Data were available from a longitudinal cohort study in Malawian drug-sensitive TB patients on standard therapy, including steady-state plasma antibiotic exposure (154 patients), sputum bacillary load (102 patients), final outcome (95 patients), and clinical details. Population pharmacokinetic and pharmacokinetic-pharmacodynamic models were developed in the software package NONMEM. Outcome data were analyzed using univariate logistic regression and Cox proportional hazard models in R, a free software for statistical computing. Results Higher isoniazid exposure correlated with increased bacillary killing in sputum (P < .01). Bacillary killing in sputum remained fast, with later progression to biphasic decline, in patients with higher rifampicin area under the curve (AUC)0-24 (P < .01). Serial sputum colony counting negativity at month 2 (P < .05), isoniazid CMAX (P < .05), isoniazid CMAX/minimum inhibitory concentration ([MIC] P < .01), and isoniazid AUC0-24/MIC (P < .01) correlated with treatment success but not with remaining free of TB. Slower bacillary killing (P < .05) and earlier progression to biphasic bacillary decline (P < .01) both correlate with treatment failure. Posttreatment recurrence only correlated with slower bacillary killing (P < .05). Conclusions Patterns of early bacillary clearance matter. Static measurements such as month 2 sputum conversion and pharmacokinetic parameters such as CMAX/MIC and AUC0-24/MIC were predictive of treatment failure, but modeling of quantitative longitudinal data was required to assess the risk of recurrence. Pooled individual patient data analyses from larger datasets are needed to confirm these findings.
Collapse
Affiliation(s)
- Frank Kloprogge
- Institute for Global Health, University College London, London, United Kingdom
| | - Henry C Mwandumba
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Gertrude Banda
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Mercy Kamdolozi
- Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Doris Shani
- Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Elizabeth L Corbett
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi.,London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Steve Ward
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Saye H Khoo
- Department of Pharmacology, University of Liverpool, Liverpool, United Kingdom
| | - Geraint R Davies
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Institute of Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Derek J Sloan
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi.,Institute of Global Health, University of Liverpool, Liverpool, United Kingdom.,School of Medicine, University of St Andrews, St Andrews, United Kingdom
| |
Collapse
|
20
|
Baron VO, Chen M, Hammarstrom B, Hammond RJH, Glynne-Jones P, Gillespie SH, Dholakia K. Real-time monitoring of live mycobacteria with a microfluidic acoustic-Raman platform. Commun Biol 2020; 3:236. [PMID: 32409770 PMCID: PMC7224385 DOI: 10.1038/s42003-020-0915-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/26/2020] [Indexed: 12/27/2022] Open
Abstract
Tuberculosis (TB) remains a leading cause of death worldwide. Lipid rich, phenotypically antibiotic tolerant, bacteria are more resistant to antibiotics and may be responsible for relapse and the need for long-term TB treatment. We present a microfluidic system that acoustically traps live mycobacteria, M. smegmatis, a model organism for M. tuberculosis. We then perform optical analysis in the form of wavelength modulated Raman spectroscopy (WMRS) on the trapped M. smegmatis for up to eight hours, and also in the presence of isoniazid (INH). The Raman fingerprints of M. smegmatis exposed to INH change substantially in comparison to the unstressed condition. Our work provides a real-time assessment of the impact of INH on the increase of lipids in these mycobacteria, which could render the cells more tolerant to antibiotics. This microfluidic platform may be used to study any microorganism and to dynamically monitor its response to different conditions and stimuli.
Collapse
Affiliation(s)
- Vincent O Baron
- School of Medicine, University of St Andrews, KY16 9TF, St Andrews, UK
| | - Mingzhou Chen
- SUPA, School of Physics and Astronomy, University of St Andrews, KY16 9SS, St Andrews, UK.
| | - Björn Hammarstrom
- School of Engineering, University of Southampton, SO17 1BJ, Southampton, UK
| | | | - Peter Glynne-Jones
- School of Engineering, University of Southampton, SO17 1BJ, Southampton, UK
| | | | - Kishan Dholakia
- SUPA, School of Physics and Astronomy, University of St Andrews, KY16 9SS, St Andrews, UK
- Department of Physics, College of Science, Yonsei University, Seoul, 03722, South Korea
| |
Collapse
|
21
|
Khandazhinskaya AL, Matyugina ES, Alexandrova LA, Kezin VA, Chernousova LN, Smirnova TG, Andreevskaya SN, Popenko VI, Leonova OG, Kochetkov SN. Interaction of 5-substituted pyrimidine nucleoside analogues and M.Tuberculosis: A view through an electron microscope. Biochimie 2020; 171-172:170-177. [PMID: 32147512 DOI: 10.1016/j.biochi.2020.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/03/2020] [Indexed: 01/17/2023]
Abstract
The data of transmission electron microscopy (TEM) on morphology of M. tuberculosis H37Rv bacterial cells treated with four analogues of pyrimidine nucleosides with different substituents at 5 position of base are presented. We showed that the growth of M. tuberculosis H37Rv cells effectively inhibited by each of these compounds. This process is accompanied with the accumulation of lipid intracellular vacuole-like inclusions in the cells, appearance of deep protrusions and indentations on the surface, partial and/or complete destruction of the three-layered cell envelope. The exact molecular mechanism of action of 5-substituted pyrimidine nucleosides on M. tuberculosis cells remains to be proved. However, one can suggest that mechanism of action for these compounds is related either to their direct interactions with bacteria cell walls or to interactions with enzymes participating in the process of cell wall formation.
Collapse
Affiliation(s)
- Anastasia L Khandazhinskaya
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russia.
| | - Elena S Matyugina
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russia.
| | - Liudmila A Alexandrova
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russia.
| | - Vasiliy A Kezin
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russia
| | - Larisa N Chernousova
- Central Tuberculosis Research Institute, 2 Yauzskaya Alley, Moscow, 107564, Russia.
| | - Tatiana G Smirnova
- Central Tuberculosis Research Institute, 2 Yauzskaya Alley, Moscow, 107564, Russia.
| | - Sofya N Andreevskaya
- Central Tuberculosis Research Institute, 2 Yauzskaya Alley, Moscow, 107564, Russia.
| | - Vladimir I Popenko
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russia.
| | - Olga G Leonova
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russia.
| | - Sergey N Kochetkov
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russia.
| |
Collapse
|
22
|
Lienhardt C, Nunn A, Chaisson R, Vernon AA, Zignol M, Nahid P, Delaporte E, Kasaeva T. Advances in clinical trial design: Weaving tomorrow's TB treatments. PLoS Med 2020; 17:e1003059. [PMID: 32106220 PMCID: PMC7046183 DOI: 10.1371/journal.pmed.1003059] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Christian Lienhardt and co-authors discuss the conclusions of the PLOS Medicine Collection on advances in clinical trial design for development of new tuberculosis treatments.
Collapse
Affiliation(s)
- Christian Lienhardt
- Unité Mixte Internationale TransVIHMI, UMI 233 IRD–U1175 INSERM—Université de Montpellier, Institut de Recherche pour le Développement (IRD), Montpellier, France
- * E-mail:
| | - Andrew Nunn
- MRC Clinical Trials Unit at UCL, Institute of Clinical Trials and Methodology, University College London, London, United Kingdom
| | - Richard Chaisson
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, United States of America
| | - Andrew A. Vernon
- Division of TB Elimination, National Center for HIV, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Matteo Zignol
- Global TB Programme, World Health Organization, Geneva, Switzerland
| | - Payam Nahid
- UCSF Center for Tuberculosis and Division of Pulmonary and Critical Care Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Eric Delaporte
- Unité Mixte Internationale TransVIHMI, UMI 233 IRD–U1175 INSERM—Université de Montpellier, Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Tereza Kasaeva
- Global TB Programme, World Health Organization, Geneva, Switzerland
| |
Collapse
|
23
|
Intracellular Pharmacodynamic Modeling Is Predictive of the Clinical Activity of Fluoroquinolones against Tuberculosis. Antimicrob Agents Chemother 2019; 64:AAC.00989-19. [PMID: 31611354 PMCID: PMC7187570 DOI: 10.1128/aac.00989-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/18/2019] [Indexed: 11/20/2022] Open
Abstract
Clinical studies of new antitubercular drugs are costly and time-consuming. Owing to the extensive tuberculosis (TB) treatment periods, the ability to identify drug candidates based on their predicted clinical efficacy is vital to accelerate the pipeline of new therapies. Recent failures of preclinical models in predicting the activity of fluoroquinolones underline the importance of developing new and more robust predictive tools that will optimize the design of future trials. Clinical studies of new antitubercular drugs are costly and time-consuming. Owing to the extensive tuberculosis (TB) treatment periods, the ability to identify drug candidates based on their predicted clinical efficacy is vital to accelerate the pipeline of new therapies. Recent failures of preclinical models in predicting the activity of fluoroquinolones underline the importance of developing new and more robust predictive tools that will optimize the design of future trials. Here, we used high-content imaging screening and pharmacodynamic intracellular (PDi) modeling to identify and prioritize fluoroquinolones for TB treatment. In a set of studies designed to validate this approach, we show moxifloxacin to be the most effective fluoroquinolone, and PDi modeling-based Monte Carlo simulations accurately predict negative culture conversion (sputum sterilization) rates compared to eight independent clinical trials. In addition, PDi-based simulations were used to predict the risk of relapse. Our analyses show that the duration of treatment following culture conversion can be used to predict the relapse rate. These data further support that PDi-based modeling offers a much-needed decision-making tool for the TB drug development pipeline.
Collapse
|
24
|
Genetic diversity of Mycobacterium tuberculosis clinical isolates in Blantyre, Malawi. Heliyon 2019; 5:e02638. [PMID: 31667430 PMCID: PMC6812180 DOI: 10.1016/j.heliyon.2019.e02638] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/30/2019] [Accepted: 10/08/2019] [Indexed: 11/22/2022] Open
Abstract
Despite the high burden of tuberculosis (TB) worldwide, specific factors influencing disease transmission remain elusive. Long term epidemiological studies and in vitro experimental models provide evidence of variable relative fitness of Mycobacterium tuberculosis (Mtb) strains but few such studies are available. Large sequence polymorphisms (LSP) are a robust molecular marker and are feasible as an epidemiological investigative tool. Few Mtb molecular epidemiological studies have been reported in Malawi owing to lack of laboratories with molecular tools. We characterized the genetic diversity of Mtb clinical isolates amongst TB patients in Blantyre, Malawi. We genotyped 64 Mtb clinical isolates using LSP-PCR, assigned specific lineages and confirmed 18 of the isolates using SMRT sequencing. The 64 isolates clustered into 4 lineages (L1-L4) with L4 predominating. There were 10/64 (16%) isolates belonging to L1, 6/64 (9%) belonging to L2, 2/64 (3%) belonging to L3 and 46/64 (72%) belonging to L4. Comparison with a previous study done in Karonga revealed concordance in L1 and L4 but discodance in L2 and L3. The phylogenetic tree constructed, comprised of 3/4 lineages present in Blantyre with 3/18 belonging to L1, 3/18 belonging to L2 and 12/18 belonging to L4. Four Mtb lineages were present in Blantyre with L4 predominating. Larger studies are needed to understand the molecular epidemiology of TB in Blantyre in light of increased bi-directional migration with South Africa.
Collapse
|
25
|
Model-Based Relationship between the Molecular Bacterial Load Assay and Time to Positivity in Liquid Culture. Antimicrob Agents Chemother 2019; 63:AAC.00652-19. [PMID: 31358585 DOI: 10.1128/aac.00652-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/23/2019] [Indexed: 11/20/2022] Open
Abstract
The molecular bacterial load (MBL) assay is a new tuberculosis biomarker which provides results in ∼4 hours. The relationship between MBL and time-to-positivity (TTP) has not been thoroughly studied, and predictive models do not exist. We aimed to develop a model for MBL and identify the MBL-TTP relationship in patients. The model was developed on data from 105 tuberculosis patients from Malawi, Mozambique, and Tanzania with joint MBL and TTP observations quantified from patient sputum collected for 12 weeks. MBL was quantified using PCR of mycobacterial RNA and TTP using the mycobacterial growth indicator tube (MGIT) 960 system. Treatment consisted of isoniazid, pyrazinamide, and ethambutol in standard doses together with rifampin 10 or 35 mg/kg of body weight. The developed MBL-TTP model included several linked submodels, a component describing decline of bacterial load in sputum, another component describing growth in liquid culture, and a hazard model translating bacterial growth into a TTP signal. Additional components for contaminated and negative TTP samples were included. Visual predictive checks performed using the developed model gave good description of the observed data. The model predicted greater total sample loss for TTP than MBL due to contamination and negative samples. The model detected an increase in bacterial killing for 35 versus 10 mg/kg rifampin (P = 0.002). In conclusion, a combined model for MBL and TTP was developed that described the MBL-TTP relationship. The full MBL-TTP model or each submodel was used separately. Second, the model can be used to predict biomarker response for MBL given TTP data or vice versa in historical or future trials.
Collapse
|
26
|
Accelerating the transition of new tuberculosis drug combinations from Phase II to Phase III trials: New technologies and innovative designs. PLoS Med 2019; 16:e1002851. [PMID: 31287813 PMCID: PMC6615592 DOI: 10.1371/journal.pmed.1002851] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Geraint Davies and colleagues discuss the potential for innovative early-phase clinical trial methods and technologies to reduce risk and speed up drug development for tuberculosis.
Collapse
|
27
|
Molecular Bacterial Load Assay Concurs with Culture on NaOH-Induced Loss of Mycobacterium tuberculosis Viability. J Clin Microbiol 2019; 57:JCM.01992-18. [PMID: 31018981 DOI: 10.1128/jcm.01992-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/17/2019] [Indexed: 12/21/2022] Open
Abstract
Effective methods to detect viable Mycobacterium tuberculosis, the main causative agent of tuberculosis (TB), are urgently needed. To date, cultivation of M. tuberculosis is the gold standard, which depends on initial sample processing with N-acetyl-l-cysteine-sodium hydroxide (NALC-NaOH), chemicals that compromise M. tuberculosis viability and, consequently, the performance of downstream tests. We applied culture and the novel molecular bacterial load assay (MBLA) to measure the loss of M. tuberculosis viability following NALC-NaOH treatment of M. tuberculosis H37Rv pure culture and clinical sputum samples from pulmonary TB patients. Compared to the bacterial loads of untreated controls, NALC-NaOH treatment of M. tuberculosis reduced the MBLA-detectable bacillary load (estimated number of CFU [eCFU] per milliliter) by 0.66 ± 0.21 log10 at 23°C (P = 0.018) and 0.72 ± 0.08 log10 at 30°C (P = 0.013). Likewise, NALC-NaOH treatment reduced the viable count on solid culture by 0.84 ± 0.02 log10 CFU/ml at 23°C (P < 0.001) and 0.85 ± 0.01 log10 CFU/ml at 30°C (P < 0.001), respectively. The reduction in the viable count was reflected by a corresponding increase in the time to positivity of the mycobacterial growth indicator tube (MGIT) liquid culture: 1.2 days at 23°C (P < 0.001) and 1.1 days at 30°C (P < 0.001). This NaOH-induced M. tuberculosis viability loss was replicated in clinical sputum samples, with the bacterial load dropping by 0.65 ± 0.17 log10 from 5.36 ± 0.24 log10 eCFU/ml to 4.71 ± 0.16 log10 eCFU/ml for untreated and treated sputa, respectively. Applying the model of Bowness et al. (R. Bowness, M. J. Boeree, R. Aarnoutse, R. Dawson, et al., J Antimicrob Chemother 70:448-455, 2015, https://doi.org/10.1093/jac/dku415) revealed that the treated MGIT time to culture positivity of 142 ± 7.02 h was equivalent to 4.86 ± 0.28 log10 CFU, consistent with the MBLA-measured bacterial load. Our study confirms the contribution of NALC-NaOH treatment to the loss of viable bacterial counts. Tests that obviate the need for decontamination may offer an alternative option for the accurate detection of viable M. tuberculosis and treatment response monitoring.
Collapse
|
28
|
Choudhary E, Sharma R, Kumar Y, Agarwal N. Conditional Silencing by CRISPRi Reveals the Role of DNA Gyrase in Formation of Drug-Tolerant Persister Population in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2019; 9:70. [PMID: 30972304 PMCID: PMC6443821 DOI: 10.3389/fcimb.2019.00070] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 03/04/2019] [Indexed: 12/21/2022] Open
Abstract
Drug tolerance in mycobacterial pathogens is a global concern. Fluoroquinolone (FQ) treatment is widely used for induction of persisters in bacteria. Although FQs that target DNA gyrase are currently used as second-line anti-tuberculosis (TB) drugs, little is known about their impact on Mycobacterium tuberculosis (Mtb) persister formation. Here we explored the CRISPRi-based genetic repression for better understanding the effect of DNA gyrase depletion on Mtb physiology and response to anti-TB drugs. We find that suppression of DNA gyrase drastically affects intra- and extracellular growth of Mtb. Interestingly, gyrase depletion in Mtb leads to activation of RecA/LexA-mediated SOS response and drug tolerance via induction of persister subpopulation. Chemical inhibition of RecA in gyrase-depleted bacteria results in reversion of persister phenotype and better killing by antibiotics. This study provides evidence that inhibition of SOS response can be advantageous in improving the efficacy of anti-TB drugs and shortening the duration of current TB treatment.
Collapse
Affiliation(s)
- Eira Choudhary
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India.,Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
| | - Rishabh Sharma
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Yashwant Kumar
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Nisheeth Agarwal
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| |
Collapse
|
29
|
Magombedze G, Pasipanodya JG, Srivastava S, Deshpande D, Visser ME, Chigutsa E, McIlleron H, Gumbo T. Transformation Morphisms and Time-to-Extinction Analysis That Map Therapy Duration From Preclinical Models to Patients With Tuberculosis: Translating From Apples to Oranges. Clin Infect Dis 2018; 67:S349-S358. [PMID: 30496464 PMCID: PMC6260172 DOI: 10.1093/cid/ciy623] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background A major challenge in medicine is translation of preclinical model findings to humans, especially therapy duration. One major example is recent shorter-duration therapy regimen failures in tuberculosis. Methods We used set theory mapping to develop a computational/modeling framework to map the time it takes to extinguish the Mycobacterium tuberculosis population on chemotherapy from multiple hollow fiber system model of tuberculosis (HFS-TB) experiments to that observed in patients. The predictive accuracy of the derived translation transformations was then tested using data from 108 HFS-TB Rapid Evaluation of Moxifloxacin in Tuberculosis (REMoxTB) units, including 756 colony-forming units (CFU)/mL. Derived transformations, and Latin hypercube sampling-guided simulations were used to predict cure and relapse after 4 and 6 months of therapy. Outcomes were compared to observations, in 1932 patients in the REMoxTB clinical trial. Results HFS-TB serial bacillary burden and serial sputum data in the derivation dataset formed a structure-preserving map. Bactericidal effect was mapped with a single step transformation, while the sterilizing effect was mapped with a 3-step transformation function. Using the HFS-TB REMoxTB data, we accurately predicted the proportion of patients cured in the 4-month REMoxTB clinical trial. Model-predicted vs clinical trial observations were (i) the ethambutol arm (77.0% [95% confidence interval {CI}, 74.4%-79.6%] vs 77.7% [95% CI, 74.3%-80.9%]) and (ii) the isoniazid arm (76.4% [95% CI, 73.9%-79.0%] vs 79.5% [95% CI, 76.1%-82.5%]). Conclusions We developed a method to translate duration of therapy outcomes from preclinical models to tuberculosis patients.
Collapse
Affiliation(s)
- Gesham Magombedze
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Dallas, Texas
| | - Jotam G Pasipanodya
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Dallas, Texas
| | - Shashikant Srivastava
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Dallas, Texas
| | - Devyani Deshpande
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Dallas, Texas
| | - Marianne E Visser
- Division of Pharmacology, Department of Medicine, University of Cape Town, Observatory, South Africa
| | - Emmanuel Chigutsa
- Division of Pharmacology, Department of Medicine, University of Cape Town, Observatory, South Africa
| | - Helen McIlleron
- Division of Pharmacology, Department of Medicine, University of Cape Town, Observatory, South Africa
| | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Dallas, Texas
| |
Collapse
|
30
|
Sauer CM, Sasson D, Paik KE, McCague N, Celi LA, Sánchez Fernández I, Illigens BMW. Feature selection and prediction of treatment failure in tuberculosis. PLoS One 2018; 13:e0207491. [PMID: 30458029 PMCID: PMC6245785 DOI: 10.1371/journal.pone.0207491] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/28/2018] [Indexed: 12/16/2022] Open
Abstract
Background Tuberculosis is a major cause of morbidity and mortality in the developing world. Drug resistance, which is predicted to rise in many countries worldwide, threatens tuberculosis treatment and control. Objective To identify features associated with treatment failure and to predict which patients are at highest risk of treatment failure. Methods On a multi-country dataset managed by the National Institute of Allergy and Infectious Diseases we applied various machine learning techniques to identify factors statistically associated with treatment failure and to predict treatment failure based on baseline demographic and clinical characteristics alone. Results The complete-case analysis database consisted of 587 patients (68% males) with a median (p25-p75) age of 40 (30–51) years. Treatment failure occurred in approximately one fourth of the patients. The features most associated with treatment failure were patterns of drug sensitivity, imaging findings, findings in the microscopy Ziehl-Nielsen stain, education status, and employment status. The most predictive model was forward stepwise selection (AUC: 0.74), although most models performed at or above AUC 0.7. A sensitivity analysis using the 643 original patients filling the missing values with multiple imputation showed similar predictive features and generally increased predictive performance. Conclusion Machine learning can help to identify patients at higher risk of treatment failure. Closer monitoring of these patients may decrease treatment failure rates and prevent emergence of antibiotic resistance. The use of inexpensive basic demographic and clinical features makes this approach attractive in low and middle-income countries.
Collapse
Affiliation(s)
- Christopher Martin Sauer
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, United States of America
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- * E-mail:
| | - David Sasson
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, United States of America
| | - Kenneth E. Paik
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Ned McCague
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Leo Anthony Celi
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Iván Sánchez Fernández
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Ben M. W. Illigens
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States of America
| |
Collapse
|
31
|
Pulmonary Tuberculosis Conversion Documented by Microscopic Staining for Detection of Dynamic, Dormant, and Dead Mycobacteria (DDD Staining). J Clin Microbiol 2018; 56:JCM.01108-18. [PMID: 30045865 DOI: 10.1128/jcm.01108-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
32
|
Kennedy JA, Baron VO, Hammond RJH, Sloan DJ, Gillespie SH. Centrifugation and decontamination procedures selectively impair recovery of important populations in Mycobacterium smegmatis. Tuberculosis (Edinb) 2018; 112:79-82. [PMID: 30205972 DOI: 10.1016/j.tube.2018.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 07/28/2018] [Accepted: 07/31/2018] [Indexed: 10/28/2022]
Abstract
Diagnosis and treatment monitoring of patients with tuberculosis (TB) requires detection of all viable mycobacteria in clinical samples. Quantitation of Mycobacterium tuberculosis (Mtb) in sputum is commonly performed by culture after sample decontamination to prevent overgrowth by contaminant organisms. Exponentially growing cultures have cells that predominately lack non-polar lipid bodies whereas stationary cultures have a predominance of cells with non-polar lipid bodies. This may reflect rapidly growing 'active' and non-replicating 'persister' sub-populations respectively in sputum from TB patients. We investigated the effect of decontamination on culture-based quantitation of exponential and stationary phase cultures of Mycobacterium smegmatis in an artificial sputum model. Exponentially growing populations were between 89 and 50 times more susceptible to decontamination than stationary phase cultures when quantified by most probable number and colony forming units. These findings suggest that decontamination selectively eliminates the 'active' population. This may impair diagnostic sensitivity, treatment monitoring, and compromise clinical trials designed to identify new antibiotic combinations with activity against all mycobacterial cell states.
Collapse
Affiliation(s)
- John A Kennedy
- School of Medicine, University of St Andrews, Fife, United Kingdom
| | - Vincent O Baron
- School of Medicine, University of St Andrews, Fife, United Kingdom
| | | | - Derek J Sloan
- School of Medicine, University of St Andrews, Fife, United Kingdom
| | | |
Collapse
|
33
|
Svensson EM, Karlsson MO. Modelling of mycobacterial load reveals bedaquiline's exposure-response relationship in patients with drug-resistant TB. J Antimicrob Chemother 2018; 72:3398-3405. [PMID: 28961790 PMCID: PMC5890768 DOI: 10.1093/jac/dkx317] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/31/2017] [Indexed: 11/13/2022] Open
Abstract
Background Bedaquiline has been shown to reduce time to sputum culture conversion (SCC) and increase cure rates in patients with drug-resistant TB, but the influence of drug exposure remains uncharacterized. Objectives To investigate whether an exposure–response relationship could be characterized by making better use of the existing information on pharmacokinetics and longitudinal measurements of mycobacterial load. Methods Quantitative culture data in the form of time to positivity (TTP) in mycobacterial growth indicator tubes obtained from a randomized placebo-controlled Phase IIb registration trial were examined using non-linear mixed-effects methodology. The link to individual bedaquiline exposures and other patient characteristics was evaluated. Results The developed model included three simultaneously fitted components: a longitudinal representation of mycobacterial load in patients, a probabilistic component for bacterial presence in sputum samples, and a time-to-event model for TTP. Data were described adequately, and time to SCC was well predicted. Individual bedaquiline exposure was found to significantly affect the decline in mycobacterial load. Consequently, the proportion of patients without SCC at week 20 is expected to decrease from 25% (95% CI 20%–31%) without bedaquiline to 17% (95% CI 13%–21%), 12% (95% CI 8%–16%) and 7% (95% CI 4%–11%), respectively, with half the median, median and double the median bedaquiline exposure observed in patients with standard dosing. Baseline bacterial load and level of drug resistance were other important predictors. Conclusions To our knowledge, this is the first successful description of bedaquiline’s exposure–response relationship and may be used when considering dose optimization. Characterization of this relationship was possible by integrating quantitative information in existing clinical data using novel models.
Collapse
Affiliation(s)
- Elin M Svensson
- Department of Pharmaceutical Biosciences, Uppsala University, PO Box 591, 751 24 Uppsala, Sweden
| | - Mats O Karlsson
- Department of Pharmaceutical Biosciences, Uppsala University, PO Box 591, 751 24 Uppsala, Sweden
| |
Collapse
|
34
|
Comparison of the validity of smear and culture conversion as a prognostic marker of treatment outcome in patients with multidrug-resistant tuberculosis. PLoS One 2018; 13:e0197880. [PMID: 29791488 PMCID: PMC5965863 DOI: 10.1371/journal.pone.0197880] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/10/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The World Health Organization (WHO) has conditionally recommended the use of sputum smear microscopy and culture examination for the monitoring of multidrug-resistant tuberculosis (MDR-TB) treatment. We aimed to assess and compare the validity of smear and culture conversion at different time points during treatment for MDR-TB, as a prognostic marker for end-of-treatment outcomes. METHODS We undertook a retrospective observational cohort study using data obtained from Hunan Chest Hospital, China and Gondar University Hospital, Ethiopia. The sensitivity and specificity of culture and sputum smear conversion for predicting treatment outcomes were analysed using a random-effects generalized linear mixed model. RESULTS A total of 429 bacteriologically confirmed MDR-TB patients with a culture and smear positive result were included. Overall, 345 (80%) patients had a successful treatment outcome, and 84 (20%) patients had poor treatment outcomes. The sensitivity of smear and culture conversion to predict a successful treatment outcome were: 77.9% and 68.9% at 2 months after starting treatment (difference between tests, p = 0.007); 95.9% and 92.7% at 4 months (p = 0.06); 97.4% and 96.2% at 6 months (p = 0.386); and 99.4% and 98.9% at 12 months (p = 0.412), respectively. The specificity of smear and culture non-conversion to predict a poor treatment outcome were: 41.6% and 60.7% at 2 months (p = 0.012); 23.8% and 48.8% at 4 months (p<0.001); and 20.2% and 42.8% at 6 months (p<0.001); and 15.4% and 32.1% (p<0.001) at 12 months, respectively. The sensitivity of culture and smear conversion increased as the month of conversion increased but at the cost of decreased specificity. The optimum time points after conversion to provide the best prognostic marker of a successful treatment outcome were between two and four months after treatment commencement for smear, and between four and six months for culture. The common optimum time point for smear and culture conversion was four months. At this time point, culture conversion (AUROC curve = 0.71) was significantly better than smear conversion (AUROC curve = 0.6) in predicting successful treatment outcomes (p < 0.001). However, the validity of smear conversion (AUROC curve = 0.7) was equivalent to culture conversion (AUROC curve = 0.71) in predicting treatment outcomes when demographic and clinical factors were included in the model. The positive and negative predictive values for smear conversion were: 57.3% and 65.7% at two months, 55.7% and 85.4% at four months, and 55.0% and 88.6% at six months; and for culture conversions it was: 63.7% and 66.2% at two months, 64.4% and 87.1% at four months, and 62.7% and 91.9% at six months, respectively. CONCLUSIONS The validity of smear conversion is significantly lower than culture conversion in predicting MDR-TB treatment outcomes. We support the WHO recommendation of using both smear and culture examination rather than smear alone for the monitoring of MDR-TB patients for a better prediction of successful treatment outcomes. The optimum time points to predict a future successful treatment outcome were between two and four months after treatment commencement for sputum smear conversion and between four and six months for culture conversion. The common optimum times for culture and smear conversion together was four months.
Collapse
|
35
|
Svensson RJ, Svensson EM, Aarnoutse RE, Diacon AH, Dawson R, Gillespie SH, Moodley M, Boeree MJ, Simonsson USH. Greater Early Bactericidal Activity at Higher Rifampicin Doses Revealed by Modeling and Clinical Trial Simulations. J Infect Dis 2018; 218:991-999. [DOI: 10.1093/infdis/jiy242] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 04/24/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Robin J Svensson
- Department of Pharmaceutical Biosciences, Uppsala University, Sweden
| | - Elin M Svensson
- Department of Pharmaceutical Biosciences, Uppsala University, Sweden
- Department of Pharmacy, Radboud Institute for Health Sciences, Nijmegen
| | - Rob E Aarnoutse
- Department of Pharmacy, Radboud Institute for Health Sciences, Nijmegen
| | | | - Rodney Dawson
- Division of Pulmonology, Department of Medicine, University of Cape Town, Cape Town, South Africa
- University of Cape Town Lung Institute, Cape Town, South Africa
| | | | | | - Martin J Boeree
- Department of Lung Diseases, Radboud University Medical Center, Nijmegen
- University Center for Chronic Diseases Dekkerswald, Groesbeek, the Netherlands
| | | |
Collapse
|
36
|
Goletti D, Lee MR, Wang JY, Walter N, Ottenhoff THM. Update on tuberculosis biomarkers: From correlates of risk, to correlates of active disease and of cure from disease. Respirology 2018; 23:455-466. [PMID: 29457312 DOI: 10.1111/resp.13272] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 12/18/2017] [Accepted: 01/22/2018] [Indexed: 12/23/2022]
Abstract
Tuberculosis (TB) remains a devastating disease, yet despite its enormous toll on global health, tools to control TB are insufficient and often outdated. TB Biomarkers (TB-BM) would constitute extremely useful tools to measure infection status and predict outcome of infection, vaccination or therapy. There are several types of TB-BM: Correlate of Infection; Correlate of TB Disease; Correlate of Increased Risk of Developing Active TB Disease; Correlate of the Curative Response to Therapy; and Correlate of Protection (CoP). Most TB-BM currently studied are host-derived BM, and consist of transcriptomic, proteomic, metabolomic, cellular markers or marker combinations ('signatures'). In particular, vaccine-inducible CoP are expected to be transformative in developing new TB vaccines as they will de-risk vaccine research and development (R&D) as well as human testing at an early stage. In addition, CoP could also help minimizing the need for preclinical studies in experimental animals. Of key importance is that TB-BM are tested and validated in different well-characterized human TB cohorts, preferably with complementary profiles and geographically diverse populations: genetic and environmental factors such as (viral) coinfections, exposure to non-tuberculous mycobacteria, nutritional status, metabolic status, age (infants vs children vs adolescents vs adults) and other factors impact host immune set points and host responses across different populations. In this study, we review the most recent advances in research into TB-BM for the diagnosis of active TB, risk of TB development and treatment-induced TB cure.
Collapse
Affiliation(s)
- Delia Goletti
- Translational Research Unit, Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases "L. Spallanzani", Rome, Italy
| | - Meng-Rui Lee
- Department of Internal Medicine, National Taiwan University Hospital, Hsinchu, Taiwan
| | - Jann-Yuan Wang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Nicholas Walter
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO, USA
| | - Tom H M Ottenhoff
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
37
|
Sarathy JP, Via LE, Weiner D, Blanc L, Boshoff H, Eugenin EA, Barry CE, Dartois VA. Extreme Drug Tolerance of Mycobacterium tuberculosis in Caseum. Antimicrob Agents Chemother 2018; 62:e02266-17. [PMID: 29203492 PMCID: PMC5786764 DOI: 10.1128/aac.02266-17] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/29/2017] [Indexed: 11/26/2022] Open
Abstract
Tuberculosis (TB) recently became the leading infectious cause of death in adults, while attempts to shorten therapy have largely failed. Dormancy, persistence, and drug tolerance are among the factors driving the long therapy duration. Assays to measure in situ drug susceptibility of Mycobacterium tuberculosis bacteria in pulmonary lesions are needed if we are to discover new fast-acting regimens and address the global TB threat. Here we take a first step toward this goal and describe an ex vivo assay developed to measure the cidal activity of anti-TB drugs against M. tuberculosis bacilli present in cavity caseum obtained from rabbits with active TB. We show that caseum M. tuberculosis bacilli are largely nonreplicating, maintain viability over the course of the assay, and exhibit extreme tolerance to many first- and second-line TB drugs. Among the drugs tested, only the rifamycins fully sterilized caseum. A similar trend of phenotypic drug resistance was observed in the hypoxia- and starvation-induced nonreplicating models, but with notable qualitative and quantitative differences: (i) caseum M. tuberculosis exhibits higher drug tolerance than nonreplicating M. tuberculosis in the Wayne and Loebel models, and (ii) pyrazinamide is cidal in caseum but has no detectable activity in these classic nonreplicating assays. Thus, ex vivo caseum constitutes a unique tool to evaluate drug potency against slowly replicating or nonreplicating bacilli in their native caseous environment. Intracaseum cidal concentrations can now be related to the concentrations achieved in the necrotic foci of granulomas and cavities to establish correlations between clinical outcome and lesion-centered pharmacokinetics-pharmacodynamics (PK-PD) parameters.
Collapse
Affiliation(s)
- Jansy P Sarathy
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Laura E Via
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, NIAID, NIH, Bethesda, Maryland, USA
- Institute of Infectious Disease and Molecular Medicine, Department of Clinical Laboratory Sciences, University of Cape Town, Cape Town, South Africa
| | - Danielle Weiner
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, NIAID, NIH, Bethesda, Maryland, USA
| | - Landry Blanc
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Helena Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, NIAID, NIH, Bethesda, Maryland, USA
| | - Eliseo A Eugenin
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
- Department of Microbiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Clifton E Barry
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, NIAID, NIH, Bethesda, Maryland, USA
- Institute of Infectious Disease and Molecular Medicine, Department of Clinical Laboratory Sciences, University of Cape Town, Cape Town, South Africa
| | - Véronique A Dartois
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
- Department of Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| |
Collapse
|
38
|
Vijay S, Hai HT, Thu DDA, Johnson E, Pielach A, Phu NH, Thwaites GE, Thuong NTT. Ultrastructural Analysis of Cell Envelope and Accumulation of Lipid Inclusions in Clinical Mycobacterium tuberculosis Isolates from Sputum, Oxidative Stress, and Iron Deficiency. Front Microbiol 2018; 8:2681. [PMID: 29379477 PMCID: PMC5770828 DOI: 10.3389/fmicb.2017.02681] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/22/2017] [Indexed: 11/13/2022] Open
Abstract
Introduction: Mycobacteria have several unique cellular characteristics, such as multiple cell envelope layers, elongation at cell poles, asymmetric cell division, and accumulation of intracytoplasmic lipid inclusions, which contributes to their survival under stress conditions. However, the understanding of these characteristics in clinical Mycobacterium tuberculosis (M. tuberculosis) isolates and under host stress is limited. We previously reported the influence of host stress on the cell length distribution in a large set of clinical M. tuberculosis isolates (n = 158). Here, we investigate the influence of host stress on the cellular ultrastructure of few clinical M. tuberculosis isolates (n = 8) from that study. The purpose of this study is to further understand the influence of host stress on the cellular adaptations of clinical M. tuberculosis isolates. Methods: We selected few M. tuberculosis isolates (n = 8) for analyzing the cellular ultrastructure ex vivo in sputum and under in vitro stress conditions by transmission electron microscopy. The cellular adaptations of M. tuberculosis in sputum were correlated with the ultrastructure of antibiotic sensitive and resistant isolates in liquid culture, under oxidative stress, iron deficiency, and exposure to isoniazid. Results: In sputum, M. tuberculosis accumulated intracytoplasmic lipid inclusions. In liquid culture, clinical M. tuberculosis revealed isolate to isolate variation in the extent of intracytoplasmic lipid inclusions, which were absent in the laboratory strain H37Rv. Oxidative stress, iron deficiency, and exposure to isoniazid increased the accumulation of lipid inclusions and decreased the thickness of the cell envelope electron transparent layer in M. tuberculosis cells. Furthermore, intracytoplasmic compartments were observed in iron deficient cells. Conclusion: Our ultrastructural analysis has revealed significant influence of host stress on the cellular adaptations in clinical M. tuberculosis isolates. These adaptations may contribute to the survival of M. tuberculosis under host and antibiotic stress conditions. Variation in the cellular adaptations among clinical M. tuberculosis isolates may correlate with their ability to persist in tuberculosis patients during antibiotic treatment. These observations indicate the need for further analyzing these cellular adaptations in a large set of clinical M. tuberculosis isolates. This will help to determine the significance of these cellular adaptations in the tuberculosis treatment.
Collapse
Affiliation(s)
- Srinivasan Vijay
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Hoang T Hai
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Do D A Thu
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Errin Johnson
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Anna Pielach
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Nguyen H Phu
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Guy E Thwaites
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nguyen T T Thuong
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
39
|
Baron VO, Chen M, Clark SO, Williams A, Hammond RJH, Dholakia K, Gillespie SH. Label-free optical vibrational spectroscopy to detect the metabolic state of M. tuberculosis cells at the site of disease. Sci Rep 2017; 7:9844. [PMID: 28852109 PMCID: PMC5575044 DOI: 10.1038/s41598-017-10234-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 08/07/2017] [Indexed: 02/01/2023] Open
Abstract
Tuberculosis relapse is a barrier to shorter treatment. It is thought that lipid rich cells, phenotypically resistant to antibiotics, may play a major role. Most studies investigating relapse use sputum samples although tissue bacteria may play an important role. We developed a non-destructive, label-free technique combining wavelength modulated Raman (WMR) spectroscopy and fluorescence detection (Nile Red staining) to interrogate Mycobacterium tuberculosis cell state. This approach could differentiate single "dormant" (lipid rich, LR) and "non-dormant" (lipid poor, LP) cells with high sensitivity and specificity. We applied this to experimentally infected guinea pig lung sections and were able to distinguish both cell types showing that the LR phenotype dominates in infected tissue. Both in-vitro and ex-vivo spectra correlated well, showing for the first time that Mycobacterium tuberculosis, likely to be phenotypically resistant to antibiotics, are present in large numbers in tissue. This is an important step in understanding the pathology of relapse supporting the idea that they may be caused by M. tuberculosis cells with lipid inclusions.
Collapse
Affiliation(s)
- Vincent O Baron
- School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Mingzhou Chen
- SUPA, School of Physics and Astronomy, University of St Andrews, KY16 9SS, St Andrews, UK.
| | - Simon O Clark
- Public Health England, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| | - Ann Williams
- Public Health England, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| | | | - Kishan Dholakia
- SUPA, School of Physics and Astronomy, University of St Andrews, KY16 9SS, St Andrews, UK
| | | |
Collapse
|
40
|
The importance of clinical pharmacokinetic-pharmacodynamic studies in unraveling the determinants of early and late tuberculosis outcomes. ACTA ACUST UNITED AC 2017; 2:195-212. [PMID: 30283633 PMCID: PMC6161803 DOI: 10.4155/ipk-2017-0004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/16/2017] [Indexed: 12/17/2022]
Abstract
Tuberculosis remains a major infectious cause of morbidity and mortality worldwide. Current antibiotic regimens, constructed prior to the development of modern pharmacokinetic-pharmacodynamic (PK–PD) tools, are based on incomplete understanding of exposure–response relationships in drug susceptible and multidrug resistant tuberculosis. Preclinical and population PK data suggest that clinical PK–PD studies may enable therapeutic drug monitoring for some agents and revised dosing for others. Future clinical PK–PD challenges include: incorporation of PK methods to assay free concentrations for all active metabolites; selection of appropriate early outcome measures which reflect therapeutic response; elucidation of genetic contributors to interindividual PK variability; conduct of targeted studies on special populations (including children); and measurement of PK–PD parameters at the site of disease.
Collapse
|
41
|
Genetic Determinants of the Pharmacokinetic Variability of Rifampin in Malawian Adults with Pulmonary Tuberculosis. Antimicrob Agents Chemother 2017; 61:AAC.00210-17. [PMID: 28461315 PMCID: PMC5487625 DOI: 10.1128/aac.00210-17] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/17/2017] [Indexed: 01/26/2023] Open
Abstract
Variable exposure to antituberculosis (TB) drugs, partially driven by genetic factors, may be associated with poor clinical outcomes. Previous studies have suggested an influence of the SLCO1B1 locus on the plasma area under the concentration-time curve (AUC) of rifampin. We evaluated the contribution of single nucleotide polymorphisms (SNPs) in SLCO1B1 and other candidate genes (AADAC and CES-1) to interindividual pharmacokinetic variability in Malawi. A total of 174 adults with pulmonary TB underwent sampling of plasma rifampin concentrations at 2 and 6 h postdose. Data from a prior cohort of 47 intensively sampled, similar patients from the same setting were available to support population pharmacokinetic model development in NONMEM v7.2, using a two-stage strategy to improve information during the absorption phase. In contrast to recent studies in South Africa and Uganda, SNPs in SLCO1B1 did not explain variability in AUC0–∞ of rifampin. No pharmacokinetic associations were identified with AADAC or CES-1 SNPs, which were rare in the Malawian population. Pharmacogenetic determinants of rifampin exposure may vary between African populations. SLCO1B1 and other novel candidate genes, as well as nongenetic sources of interindividual variability, should be further explored in geographically diverse, adequately powered cohorts.
Collapse
|
42
|
Rockwood N, Pasipanodya JG, Denti P, Sirgel F, Lesosky M, Gumbo T, Meintjes G, McIlleron H, Wilkinson RJ. Concentration-Dependent Antagonism and Culture Conversion in Pulmonary Tuberculosis. Clin Infect Dis 2017; 64:1350-1359. [PMID: 28205671 PMCID: PMC5411399 DOI: 10.1093/cid/cix158] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 02/15/2017] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND There is scant evidence to support target drug exposures for optimal tuberculosis outcomes. We therefore assessed whether pharmacokinetic/pharmacodynamic (PK/PD) parameters could predict 2-month culture conversion. METHODS One hundred patients with pulmonary tuberculosis (65% human immunodeficiency virus coinfected) were intensively sampled to determine rifampicin, isoniazid, and pyrazinamide plasma concentrations after 7-8 weeks of therapy, and PK parameters determined using nonlinear mixed-effects models. Detailed clinical data and sputum for culture were collected at baseline, 2 months, and 5-6 months. Minimum inhibitory concentrations (MICs) were determined on baseline isolates. Multivariate logistic regression and the assumption-free multivariate adaptive regression splines (MARS) were used to identify clinical and PK/PD predictors of 2-month culture conversion. Potential PK/PD predictors included 0- to 24-hour area under the curve (AUC0-24), maximum concentration (Cmax), AUC0-24/MIC, Cmax/MIC, and percentage of time that concentrations persisted above the MIC (%TMIC). RESULTS Twenty-six percent of patients had Cmax of rifampicin <8 mg/L, pyrazinamide <35 mg/L, and isoniazid <3 mg/L. No relationship was found between PK exposures and 2-month culture conversion using multivariate logistic regression after adjusting for MIC. However, MARS identified negative interactions between isoniazid Cmax and rifampicin Cmax/MIC ratio on 2-month culture conversion. If isoniazid Cmax was <4.6 mg/L and rifampicin Cmax/MIC <28, the isoniazid concentration had an antagonistic effect on culture conversion. For patients with isoniazid Cmax >4.6 mg/L, higher isoniazid exposures were associated with improved rates of culture conversion. CONCLUSIONS PK/PD analyses using MARS identified isoniazid Cmax and rifampicin Cmax/MIC thresholds below which there is concentration-dependent antagonism that reduces 2-month sputum culture conversion.
Collapse
Affiliation(s)
- Neesha Rockwood
- Department of Medicine, Imperial College London, United Kingdom
- Wellcome Center for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Jotam G Pasipanodya
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, Texas
| | - Paolo Denti
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town
| | - Frederick Sirgel
- Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research/ South African Medical Research Foundation Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Tygerberg
| | - Maia Lesosky
- Wellcome Center for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
- Division of Epidemiology and Biostatistics, School of Public Health and Family Medicine, and
| | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, Texas
- Department of Medicine, University of Cape Town, South Africa; and
| | - Graeme Meintjes
- Department of Medicine, Imperial College London, United Kingdom
- Department of Medicine, University of Cape Town, South Africa; and
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town
| | - Robert J Wilkinson
- Department of Medicine, Imperial College London, United Kingdom
- Wellcome Center for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
- Department of Medicine, University of Cape Town, South Africa; and
- Francis Crick Institute, London, United Kingdom
| |
Collapse
|
43
|
Hector J, Anderson ST, Banda G, Kamdolozi M, Jefferys LF, Shani D, Garton NJ, Mwale A, Jobe A, Davies GR, Sloan DJ. TST positivity in household contacts of tuberculosis patients: a case-contact study in Malawi. BMC Infect Dis 2017; 17:259. [PMID: 28399800 PMCID: PMC5387357 DOI: 10.1186/s12879-017-2348-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 03/28/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Screening household contacts of active tuberculosis (TB) patients is recommended for TB control. Due to resource constraints this rarely occurs in lower income countries. Demographic and clinical features of index cases may influence the likelihood of onwards TB transmission. It has also been proposed that accumulation of intracellular lipid bodies within M. tuberculosis cells may also enhance bacterial transmissibility. This study explored whether clinical and bacteriological observations recorded at baseline in TB cases in Malawi could help identify those with the highest risk of onwards transmission, to prioritise contact tracing. METHODS In this case-contact study, data on clinical presentation, sputum bacterial load and the percentage of lipid body positive acid-fast bacilli (%LB + AFB) on sputum smears were recorded in adults with sputum smear and culture positive pulmonary TB before initiation of therapy. The Tuberculin Skin Test (TST) was used to detect infection with M. tuberculosis amongst household contacts under the age of 15 years. TST positivity of the child contacts was related to characteristics of the index case. RESULTS Thirty four index cases brought 56 contacts (median: 1, range: 1-4 contacts each). 37 (66%) of contacts had a positive TST. Cavities or a high percentage of lung affected on index patient CXRs were associated with TST positivity. Multivariate analysis of non-radiological factors showed that male sex, HIV-negative status and raised peripheral blood white blood count (WBC) in index patients were also independent risk factors of TST positivity. Lower %LB + AFB counts were associated with TST positivity on univariate analysis only. CONCLUSION TST positivity is common amongst household contacts of sputum smear positive adult TB patients in Malawi. Contact tracing in this high risk population could be guided by prioritising index cases with CXR cavities and extensive radiological disease or, in the absence of CXRs, those who are HIV-negative with a raised WBC.
Collapse
Affiliation(s)
- Jonas Hector
- LSTM, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Suzanne T Anderson
- Malawi Liverpool Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi.,Section of Paediatrics and Imperial College-Wellcome Trust Centre for Global Health Research, Department of Medicine, Imperial College London, London, UK
| | - Gertrude Banda
- Malawi Liverpool Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Mercy Kamdolozi
- Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | | | - Doris Shani
- Department of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Natalie J Garton
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Agnes Mwale
- Malawi Liverpool Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Annie Jobe
- Malawi Liverpool Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Geraint R Davies
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Derek J Sloan
- Malawi Liverpool Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi.,School of Medicine, University of St Andrews, Scotland, UK
| |
Collapse
|
44
|
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.
Collapse
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
| |
Collapse
|
45
|
Boeree MJ, Heinrich N, Aarnoutse R, Diacon AH, Dawson R, Rehal S, Kibiki GS, Churchyard G, Sanne I, Ntinginya NE, Minja LT, Hunt RD, Charalambous S, Hanekom M, Semvua HH, Mpagama SG, Manyama C, Mtafya B, Reither K, Wallis RS, Venter A, Narunsky K, Mekota A, Henne S, Colbers A, van Balen GP, Gillespie SH, Phillips PPJ, Hoelscher M. High-dose rifampicin, moxifloxacin, and SQ109 for treating tuberculosis: a multi-arm, multi-stage randomised controlled trial. THE LANCET. INFECTIOUS DISEASES 2017; 17:39-49. [PMID: 28100438 PMCID: PMC5159618 DOI: 10.1016/s1473-3099(16)30274-2] [Citation(s) in RCA: 244] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/12/2016] [Accepted: 07/20/2016] [Indexed: 01/03/2023]
Abstract
BACKGROUND Tuberculosis is the world's leading infectious disease killer. We aimed to identify shorter, safer drug regimens for the treatment of tuberculosis. METHODS We did a randomised controlled, open-label trial with a multi-arm, multi-stage design. The trial was done in seven sites in South Africa and Tanzania, including hospitals, health centres, and clinical trial centres. Patients with newly diagnosed, rifampicin-sensitive, previously untreated pulmonary tuberculosis were randomly assigned in a 1:1:1:1:2 ratio to receive (all orally) either 35 mg/kg rifampicin per day with 15-20 mg/kg ethambutol, 20 mg/kg rifampicin per day with 400 mg moxifloxacin, 20 mg/kg rifampicin per day with 300 mg SQ109, 10 mg/kg rifampicin per day with 300 mg SQ109, or a daily standard control regimen (10 mg/kg rifampicin, 5 mg/kg isoniazid, 25 mg/kg pyrazinamide, and 15-20 mg/kg ethambutol). Experimental treatments were given with oral 5 mg/kg isoniazid and 25 mg/kg pyrazinamide per day for 12 weeks, followed by 14 weeks of 5 mg/kg isoniazid and 10 mg/kg rifampicin per day. Because of the orange discoloration of body fluids with higher doses of rifampicin it was not possible to mask patients and clinicians to treatment allocation. The primary endpoint was time to culture conversion in liquid media within 12 weeks. Patients without evidence of rifampicin resistance on phenotypic test who took at least one dose of study treatment and had one positive culture on liquid or solid media before or within the first 2 weeks of treatment were included in the primary analysis (modified intention to treat). Time-to-event data were analysed using a Cox proportional-hazards regression model and adjusted for minimisation variables. The proportional hazard assumption was tested using Schoelfeld residuals, with threshold p<0·05 for non-proportionality. The trial is registered with ClinicalTrials.gov (NCT01785186). FINDINGS Between May 7, 2013, and March 25, 2014, we enrolled and randomly assigned 365 patients to different treatment arms (63 to rifampicin 35 mg/kg, isoniazid, pyrazinamide, and ethambutol; 59 to rifampicin 10 mg/kg, isoniazid, pyrazinamide, SQ109; 57 to rifampicin 20 mg/kg, isoniazid, pyrazinamide, and SQ109; 63 to rifampicin 10 mg/kg, isoniazid, pyrazinamide, and moxifloxacin; and 123 to the control arm). Recruitment was stopped early in the arms containing SQ109 since prespecified efficacy thresholds were not met at the planned interim analysis. Time to stable culture conversion in liquid media was faster in the 35 mg/kg rifampicin group than in the control group (median 48 days vs 62 days, adjusted hazard ratio 1·78; 95% CI 1·22-2·58, p=0·003), but not in other experimental arms. There was no difference in any of the groups in time to culture conversion on solid media. 11 patients had treatment failure or recurrent disease during post-treatment follow-up: one in the 35 mg/kg rifampicin arm and none in the moxifloxacin arm. 45 (12%) of 365 patients reported grade 3-5 adverse events, with similar proportions in each arm. INTERPRETATION A dose of 35 mg/kg rifampicin was safe, reduced the time to culture conversion in liquid media, and could be a promising component of future, shorter regimens. Our adaptive trial design was successfully implemented in a multi-centre, high tuberculosis burden setting, and could speed regimen development at reduced cost. FUNDING The study was funded by the European and Developing Countries Clinical Trials partnership (EDCTP), the German Ministry for Education and Research (BmBF), and the Medical Research Council UK (MRC).
Collapse
Affiliation(s)
- Martin J Boeree
- Department of Lung Diseases, Radboud University Medical Center, Nijmegen, Netherlands.
| | - Norbert Heinrich
- Division of Infectious Diseases and Tropical Medicine, Medical Centre of the University of Munich, Munich, Germany,German Center for Infection Research, Partner Site Munich, Germany
| | - Rob Aarnoutse
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, Netherlands
| | - Andreas H Diacon
- Centre for Clinical Tuberculosis Research, Department of Science and Technology and National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, South Africa
| | - Rodney Dawson
- Centre for Tuberculosis Research Innovation, University of Cape Town, Grote Schuur, South Africa
| | | | - Gibson S Kibiki
- Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical Centre, Tumaini University, Moshi, Tanzania
| | - Gavin Churchyard
- Aurum Institute, Johannesburg, South Africa,School of Public Health, University of Witwatersrand, Johannesburg, South Africa,Department of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Ian Sanne
- Helen Joseph Hospital, Johannesburg, South Africa
| | - Nyanda E Ntinginya
- National Institute for Medical Research, Mbeya Medical Research Centre, Mbeya, Tanzania
| | | | - Robert D Hunt
- Division of Infection and Immunity, Centre for Clinical Microbiology, University College London, UK
| | | | - Madeleine Hanekom
- Centre for Clinical Tuberculosis Research, Department of Science and Technology and National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, South Africa
| | - Hadija H Semvua
- Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical Centre, Tumaini University, Moshi, Tanzania
| | | | - Christina Manyama
- National Institute for Medical Research, Mbeya Medical Research Centre, Mbeya, Tanzania
| | - Bariki Mtafya
- National Institute for Medical Research, Mbeya Medical Research Centre, Mbeya, Tanzania
| | - Klaus Reither
- Swiss Tropical and Public Health Institute, Basel, Switzerland,University of Basel, Basel, Switzerland
| | | | - Amour Venter
- MRC Centre for Tuberculosis Research, University of Stellenbosch, Tygerberg, South Africa
| | - Kim Narunsky
- Centre for Tuberculosis Research Innovation, University of Cape Town, Grote Schuur, South Africa
| | - Anka Mekota
- Division of Infectious Diseases and Tropical Medicine, Medical Centre of the University of Munich, Munich, Germany
| | - Sonja Henne
- Division of Infectious Diseases and Tropical Medicine, Medical Centre of the University of Munich, Munich, Germany
| | - Angela Colbers
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, Netherlands
| | | | | | | | - Michael Hoelscher
- Division of Infectious Diseases and Tropical Medicine, Medical Centre of the University of Munich, Munich, Germany,German Center for Infection Research, Partner Site Munich, Germany
| | | |
Collapse
|
46
|
Abstract
Tuberculosis (TB) remains a global threat with more than 9 million new infections. Treatment remains difficult and there has been no change in the duration of the standard regimen since the early 1980s. Moreover, many patients are unable to tolerate this treatment and discontinue therapy, increasing the risk of resistance. There is a growing tide of multidrug resistance and few effective antibiotics to tackle the problem. Since the turn of the millennium there has been a surge in interest in developing new therapies for TB and a number of new drugs have been developed. In this review the repurposing of moxifloxacin, an 8-methoxy-fluoroquinolone, for TB treatment is discussed. The evidence that underpins the development of this agent is reviewed. The results of the recently completed phase III trials are summarised and the reasons for the unexpected outcome are explored. Finally, the design of new trials that incorporate moxifloxacin, and that address both susceptible disease and multidrug resistance, is described.
Collapse
|
47
|
Dheda K, Chang KC, Guglielmetti L, Furin J, Schaaf HS, Chesov D, Esmail A, Lange C. Clinical management of adults and children with multidrug-resistant and extensively drug-resistant tuberculosis. Clin Microbiol Infect 2016; 23:131-140. [PMID: 27756712 DOI: 10.1016/j.cmi.2016.10.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/06/2016] [Accepted: 10/07/2016] [Indexed: 01/29/2023]
Abstract
BACKGROUND Globally there is a burgeoning epidemic of drug monoresistant tuberculosis (TB), multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Almost 20% of all TB strains worldwide are resistant to at least one major TB drug, including isoniazid. In several parts of the world there is an increasing incidence of MDR-TB, and alarmingly, almost a third of MDR-TB cases globally are resistant to either a fluoroquinolone or aminoglycoside. This trend cannot be ignored because drug-resistant TB is associated with greater morbidity compared to drug-susceptible TB, accounts for almost 25% of global TB mortality, is extremely costly to treat, consumes substantial portions of budgets allocated to national TB programmes in TB-endemic countries and is a major threat to healthcare workers, who are already in short supply in resource-poor settings. Even more worrying is the growing epidemic of resistance beyond XDR-TB, including resistance to newer drugs such as bedaquiline and delamanid, as well as the increasing prevalence of programmatically incurable TB in countries like South Africa, Russia, India and China. These developments threaten to reverse the gains already made against TB. SOURCES Articles related to MDR-TB and XDR-TB found on PubMed in all languages up to September 2016, published reviews, and files of the authors. AIM AND CONTENT To review the clinical management of adults and children with MDR- and XDR-TB with a particular emphasis on the utility of newer and repurposed drugs such as linezolid, bedaquiline and delamanid, as well as management of MDR- and XDR-TB in special situations such as in HIV-infected persons and in children. IMPLICATIONS This review informs on the prevention, diagnosis, and clinical management of MDR-TB and XDR-TB.
Collapse
Affiliation(s)
- K Dheda
- Lung Infection and Immunity Unit, Department of Medicine, Division of Pulmonology and UCT Lung Institute, University of Cape Town, Groote Schuur Hospital, Observatory, South Africa.
| | - K C Chang
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong, China
| | - L Guglielmetti
- Sanatorium, Centre Hospitalier de Bligny, Briis-sous-Forges, France; Sorbonne Université, Université Pierre et Marie Curie-Paris 6, CR7, INSERM, U1135, Centre d'Immunologie et des Maladies Infectieuses, CIMI, Team E13 (Bactériologie), Paris, France
| | - J Furin
- Harvard Medical School, Department of Global Health, and Social Medicine, Boston, MA, USA
| | - H S Schaaf
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - D Chesov
- Department of Pneumology and Allergology, State University of Medicine and Pharmacy 'Nicolae Testemitanu', Chisinau, Republic of Moldova
| | - A Esmail
- Lung Infection and Immunity Unit, Department of Medicine, Division of Pulmonology and UCT Lung Institute, University of Cape Town, Groote Schuur Hospital, Observatory, South Africa
| | - C Lange
- Division of Clinical Infectious Diseases, German Center for Infection Research (DZIF), Research Center Borstel, Borstel, 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; German Center for Infection Research, Clinical Tuberculosis Center, Borstel, Germany
| |
Collapse
|
48
|
Lipworth S, Hammond RJH, Baron VO, Hu Y, Coates A, Gillespie SH. Defining dormancy in mycobacterial disease. Tuberculosis (Edinb) 2016; 99:131-142. [PMID: 27450015 DOI: 10.1016/j.tube.2016.05.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/06/2016] [Accepted: 05/23/2016] [Indexed: 11/19/2022]
Abstract
Tuberculosis remains a threat to global health and recent attempts to shorten therapy have not succeeded mainly due to cases of clinical relapse. This has focussed attention on the importance of "dormancy" in tuberculosis. There are a number of different definitions of the term and a similar multiplicity of different in vitro and in vivo models. The danger with this is the implicit assumption of equivalence between the terms and models, which will make even more difficult to unravel this complex conundrum. In this review we summarise the main models and definitions and their impact on susceptibility of Mycobacterium tuberculosis. We also suggest a potential nomenclature for debate. Dormancy researchers agree that factors underpinning this phenomenon are complex and nuanced. If we are to make progress we must agree the terms to be used and be consistent in using them.
Collapse
Affiliation(s)
- S Lipworth
- School of Medicine, University of St Andrews, Biomedical Science Building, North Haugh, St Andrews KY16 9TF, United Kingdom
| | - R J H Hammond
- School of Medicine, University of St Andrews, Biomedical Science Building, North Haugh, St Andrews KY16 9TF, United Kingdom
| | - V O Baron
- School of Medicine, University of St Andrews, Biomedical Science Building, North Haugh, St Andrews KY16 9TF, United Kingdom
| | - Yanmin Hu
- Institute for Infection and Immunity, St George's, University of London, London SW17 ORE, United Kingdom
| | - A Coates
- Institute for Infection and Immunity, St George's, University of London, London SW17 ORE, United Kingdom
| | - S H Gillespie
- School of Medicine, University of St Andrews, Biomedical Science Building, North Haugh, St Andrews KY16 9TF, United Kingdom.
| |
Collapse
|
49
|
Svensson RJ, Simonsson U. Application of the Multistate Tuberculosis Pharmacometric Model in Patients With Rifampicin-Treated Pulmonary Tuberculosis. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2016; 5:264-73. [PMID: 27299939 PMCID: PMC4873565 DOI: 10.1002/psp4.12079] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/30/2016] [Indexed: 12/11/2022]
Abstract
This is the first clinical implementation of the Multistate Tuberculosis Pharmacometric (MTP) model describing fast-, slow-, and nonmultiplying bacterial states of Mycobacterium tuberculosis. Colony forming unit data from 19 patients treated with rifampicin were analyzed. A previously developed rifampicin population pharmacokinetic (PK) model was linked to the MTP model previously developed using in vitro data. Drug effect was implemented as exposure-response relationships tested at several effect sites, both alone and in combination. All MTP model parameters were fixed to in vitro estimates except Bmax . Drug effect was described by an on/off effect inhibiting growth of fast-multiplying bacteria in addition to linear increase of the stimulation of the death rate of slow- and nonmultiplying bacteria with increasing drug exposure. Clinical trial simulations predicted well three retrospective clinical trials using the final model that confirmed the potential utility of the MTP model in antitubercular drug development.
Collapse
Affiliation(s)
- R J Svensson
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Ush Simonsson
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| |
Collapse
|
50
|
Pienaar E, Matern WM, Linderman JJ, Bader JS, Kirschner DE. Multiscale Model of Mycobacterium tuberculosis Infection Maps Metabolite and Gene Perturbations to Granuloma Sterilization Predictions. Infect Immun 2016; 84:1650-1669. [PMID: 26975995 PMCID: PMC4862722 DOI: 10.1128/iai.01438-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 03/08/2016] [Indexed: 02/06/2023] Open
Abstract
Granulomas are a hallmark of tuberculosis. Inside granulomas, the pathogen Mycobacterium tuberculosis may enter a metabolically inactive state that is less susceptible to antibiotics. Understanding M. tuberculosis metabolism within granulomas could contribute to reducing the lengthy treatment required for tuberculosis and provide additional targets for new drugs. Two key adaptations of M. tuberculosis are a nonreplicating phenotype and accumulation of lipid inclusions in response to hypoxic conditions. To explore how these adaptations influence granuloma-scale outcomes in vivo, we present a multiscale in silico model of granuloma formation in tuberculosis. The model comprises host immunity, M. tuberculosis metabolism, M. tuberculosis growth adaptation to hypoxia, and nutrient diffusion. We calibrated our model to in vivo data from nonhuman primates and rabbits and apply the model to predict M. tuberculosis population dynamics and heterogeneity within granulomas. We found that bacterial populations are highly dynamic throughout infection in response to changing oxygen levels and host immunity pressures. Our results indicate that a nonreplicating phenotype, but not lipid inclusion formation, is important for long-term M. tuberculosis survival in granulomas. We used virtual M. tuberculosis knockouts to predict the impact of both metabolic enzyme inhibitors and metabolic pathways exploited to overcome inhibition. Results indicate that knockouts whose growth rates are below ∼66% of the wild-type growth rate in a culture medium featuring lipid as the only carbon source are unable to sustain infections in granulomas. By mapping metabolite- and gene-scale perturbations to granuloma-scale outcomes and predicting mechanisms of sterilization, our method provides a powerful tool for hypothesis testing and guiding experimental searches for novel antituberculosis interventions.
Collapse
Affiliation(s)
- Elsje Pienaar
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - William M Matern
- Department of Biomedical Engineering and High-Throughput Biology Center, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jennifer J Linderman
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Joel S Bader
- Department of Biomedical Engineering and High-Throughput Biology Center, Johns Hopkins University, Baltimore, Maryland, USA
| | - Denise E Kirschner
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| |
Collapse
|