Medical Abstracts

Keyword: tuberculosis

1. Lancet. 2019 Feb 21. pii: S0140-6736(18)32993-3. doi:

10.1016/S0140-6736(18)32993-3. [Epub ahead of print]

Smartphone-enabled video-observed versus directly observed treatment for

tuberculosis: a multicentre, analyst-blinded, randomised, controlled superiority

trial.

Story A(1), Aldridge RW(2), Smith CM(2), Garber E(3), Hall J(3), Ferenando G(3),

Possas L(3), Hemming S(3), Wurie F(2), Luchenski S(2), Abubakar I(4), McHugh

TD(5), White PJ(6), Watson JM(7), Lipman M(8), Garfein R(9), Hayward AC(10).

Author information:

(1)Institute of Health Informatics, University College London, London, UK; Find

and Treat, University College Hospitals NHS Foundation Trust, London, UK.

(2)Institute of Health Informatics, University College London, London, UK.

(3)Institute of Health Informatics, University College London, London, UK; Royal

Free London NHS Foundation Trust, London, UK.

…

BACKGROUND: Directly observed treatment (DOT) has been the standard of care for

tuberculosis since the early 1990s, but it is inconvenient for patients and

service providers. Video-observed therapy (VOT) has been conditionally

recommended by WHO as an alternative to DOT. We tested whether levels of

treatment observation were improved with VOT.

METHODS: We did a multicentre, analyst-blinded, randomised controlled superiority

trial in 22 clinics in England (UK). Eligible participants were patients aged at

least 16 years with active pulmonary or non-pulmonary tuberculosis who were

eligible for DOT according to local guidance. Exclusion criteria included

patients who did not have access to charging a smartphone. We randomly assigned

participants to either VOT (daily remote observation using a smartphone app) or

DOT (observations done three to five times per week in the home, community, or

clinic settings). Randomisation was done by the SealedEnvelope service using

minimisation. DOT involved treatment observation by a health-care or lay worker,

with any remaining daily doses self-administered. VOT was provided by a

centralised service in London. Patients were trained to record and send videos of

every dose ingested 7 days per week using a smartphone app. Trained treatment

observers viewed these videos through a password-protected website. Patients were

also encouraged to report adverse drug events on the videos. Smartphones and data

plans were provided free of charge by study investigators. DOT or VOT observation

records were completed by observers until treatment or study end. The primary

outcome was completion of 80% or more scheduled treatment observations over the

first 2 months following enrolment. Intention-to-treat (ITT) and restricted

(including only patients completing at least 1 week of observation on allocated

arm) analyses were done. Superiority was determined by a 15% difference in the

proportion of patients with the primary outcome (60% vs 75%). This trial is

registered with the International Standard Randomised Controlled Trials Number

registry, number ISRCTN26184967.

FINDINGS: Between Sept 1, 2014, and Oct 1, 2016, we randomly assigned 226

patients; 112 to VOT and 114 to DOT. Overall, 131 (58%) patients had a history of

homelessness, imprisonment, drug use, alcohol problems or mental health problems.

In the ITT analysis, 78 (70%) of 112 patients on VOT achieved ≥80% scheduled

observations successfully completed during the first 2 months compared with 35

(31%) of 114 on DOT (adjusted odds ratio [OR] 5·48, 95% CI 3·10-9·68; p<0·0001).

In the restricted analysis, 78 (77%) of 101 patients on VOT achieved the primary

outcome compared with 35 (63%) of 56 on DOT (adjusted OR 2·52; 95% CI 1·17-5·54;

p=0·017). Stomach pain, nausea, and vomiting were the most common adverse events

reported (in 16 [14%] of 112 on VOT and nine [8%] of 114 on DOT).

INTERPRETATION: VOT was a more effective approach to observation of tuberculosis

treatment than DOT. VOT is likely to be preferable to DOT for many patients

across a broad range of settings, providing a more acceptable, effective, and

cheaper option for supervision of daily and multiple daily doses than DOT.

FUNDING: National Institute for Health Research.

Copyright © 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access

article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights

reserved.

DOI: 10.1016/S0140-6736(18)32993-3

PMID: 30799062

2. Science. 2019 Feb 1;363(6426). pii: eaau8959. doi: 10.1126/science.aau8959.

Opposing reactions in coenzyme A metabolism sensitize Mycobacterium tuberculosis

to enzyme inhibition.

Ballinger E(1), Mosior J(2), Hartman T(3), Burns-Huang K(1), Gold B(1), Morris

R(3), Goullieux L(4), Blanc I(4), Vaubourgeix J(1), Lagrange S(4), Fraisse L(4),

Sans S(4), Couturier C(4), Bacqué E(4), Rhee K(3), Scarry SM(5), Aubé J(5), Yang

G(6), Ouerfelli O(6), Schnappinger D(1), Ioerger TR(1), Engelhart CA(1),

McConnell JA(1), McAulay K(1), Fay A(7), Roubert C(4), Sacchettini J(8), Nathan

C(9).

Author information:

(1)Department of Microbiology and Immunology, Weill Cornell Medicine, New York,

NY, USA.

(2)Departments of Biochemistry and Biophysics, Texas Agricultural and Mechanical

University, College Station, TX, USA.

(3)Department of Medicine, Weill Cornell Medicine, New York, NY, USA.

…

Comment in

Science. 2019 Feb 1;363(6426):457-458.

Mycobacterium tuberculosis (Mtb) is the leading infectious cause of death in

humans. Synthesis of lipids critical for Mtb's cell wall and virulence depends on

phosphopantetheinyl transferase (PptT), an enzyme that transfers

4'-phosphopantetheine (Ppt) from coenzyme A (CoA) to diverse acyl carrier

proteins. We identified a compound that kills Mtb by binding and partially

inhibiting PptT. Killing of Mtb by the compound is potentiated by another enzyme

encoded in the same operon, Ppt hydrolase (PptH), that undoes the PptT reaction.

Thus, loss-of-function mutants of PptH displayed antimicrobial resistance. Our

PptT-inhibitor cocrystal structure may aid further development of

antimycobacterial agents against this long-sought target. The opposing reactions

of PptT and PptH uncover a regulatory pathway in CoA physiology.

Copyright © 2019 The Authors, some rights reserved; exclusive licensee American

Association for the Advancement of Science. No claim to original U.S. Government

Works.

DOI: 10.1126/science.aau8959

PMID: 30705156

3. Nat Med. 2019 Feb;25(2):255-262. doi: 10.1038/s41591-018-0319-9. Epub 2019 Jan

21.

Prevention of tuberculosis infection and disease by local BCG in repeatedly

exposed rhesus macaques.

Dijkman K(1), Sombroek CC(2), Vervenne RAW(2), Hofman SO(2), Boot C(2), Remarque

EJ(2), Kocken CHM(2), Ottenhoff THM(3), Kondova I(2), Khayum MA(2), Haanstra

KG(2), Vierboom MPM(2), Verreck FAW(4).

Author information:

(1)Biomedical Primate Research Centre, Rijswijk, the Netherlands.

dijkman@bprc.nl.

(2)Biomedical Primate Research Centre, Rijswijk, the Netherlands.

(3)Department of Infectious Diseases, Leiden University Medical Centre, Leiden,

the Netherlands.

(4)Biomedical Primate Research Centre, Rijswijk, the Netherlands.

verreck@bprc.nl.

Tuberculosis (TB) remains the deadliest infectious disease1, and the widely used

Bacillus Calmette-Guérin (BCG) vaccine fails to curb the epidemic. An improved

vaccination strategy could provide a cost-effective intervention to break the

transmission cycle and prevent antimicrobial resistance2,3. Limited knowledge of

the host responses critically involved in protective immunity hampers the

development of improved TB vaccination regimens. Therefore, assessment of new

strategies in preclinical models to select the best candidate vaccines before

clinical vaccine testing remains indispensable. We have previously established in

rhesus macaques (Macaca mulatta) that pulmonary mucosal BCG delivery reduces TB

disease where standard intradermal injection fails4,5. Here, we show that

pulmonary BCG prevents infection by using a repeated limiting-dose Mycobacterium

tuberculosis challenge model and identify polyfunctional T-helper type 17 (TH17)

cells, interleukin-10 and immunoglobulin A as correlates of local protective

immunity. These findings warrant further research into mucosal immunization

strategies and their translation to clinical application to more effectively

prevent the spread of TB.

DOI: 10.1038/s41591-018-0319-9

PMID: 30664782

4. PLoS Med. 2019 Feb 27;16(2):e1002754. doi: 10.1371/journal.pmed.1002754.

eCollection 2019 Feb.

Constructing care cascades for active tuberculosis: A strategy for program

monitoring and identifying gaps in quality of care.

Subbaraman R(1)(2), Nathavitharana RR(3), Mayer KH(3)(4), Satyanarayana S(5),

Chadha VK(6), Arinaminpathy N(7), Pai M(8).

Author information:

(1)Department of Public Health and Community Medicine and Center for Global

Public Health, Tufts University School of Medicine, Boston, Massachusetts, United

States of America.

(2)Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center,

Boston, Massachusetts, United States of America.

(3)Division of Infectious Diseases, Beth Israel Deaconess Medical Center and

Harvard Medical School, Boston, Massachusetts, United States of America.

…

The cascade of care is a model for evaluating patient retention across sequential

stages of care required to achieve a successful treatment outcome. This approach

was first used to evaluate HIV care and has since been applied to other diseases.

The tuberculosis (TB) community has only recently started using care cascade

analyses to quantify gaps in quality of care. In this article, we describe

methods for estimating gaps (patient losses) and steps (patients retained) in the

care cascade for active TB disease. We highlight approaches for overcoming

challenges in constructing the TB care cascade, which include difficulties in

estimating the population-level burden of disease and the diagnostic gap due to

the limited sensitivity of TB diagnostic tests. We also describe potential uses

of this model for evaluating the impact of interventions to improve case finding,

diagnosis, linkage to care, retention in care, and post-treatment monitoring of

TB patients.

DOI: 10.1371/journal.pmed.1002754

PMCID: PMC6392267

PMID: 30811385

Conflict of interest statement: I have read the journal's policy and the authors

of this manuscript have the following competing interests: MP is a member of the

Editorial Board of PLOS Medicine. All other authors declare that no competing

interests exist.

5. Mol Cell. 2019 Feb 18. pii: S1097-2765(19)30048-6. doi:

10.1016/j.molcel.2019.01.028. [Epub ahead of print]

An NAD+ Phosphorylase Toxin Triggers Mycobacterium tuberculosis Cell Death.

Freire DM(1), Gutierrez C(2), Garza-Garcia A(3), Grabowska AD(2), Sala AJ(4),

Ariyachaokun K(2), Panikova T(1), Beckham KSH(1), Colom A(2), Pogenberg V(1),

Cianci M(1), Tuukkanen A(1), Boudehen YM(2), Peixoto A(2), Botella L(5), Svergun

DI(1), Schnappinger D(5), Schneider TR(1), Genevaux P(4), de Carvalho LPS(3),

Wilmanns M(6), Parret AHA(7), Neyrolles O(8).

Author information:

(1)European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607

Hamburg, Germany.

(2)Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de

Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France.

(3)Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick

Institute, 1 Midland Road, London NW1 1AT, UK.

…

Toxin-antitoxin (TA) systems regulate fundamental cellular processes in bacteria

and represent potential therapeutic targets. We report a new RES-Xre TA system in

multiple human pathogens, including Mycobacterium tuberculosis. The toxin, MbcT,

is bactericidal unless neutralized by its antitoxin MbcA. To investigate the

mechanism, we solved the 1.8 Å-resolution crystal structure of the MbcTA complex.

We found that MbcT resembles secreted NAD+-dependent bacterial exotoxins, such as

diphtheria toxin. Indeed, MbcT catalyzes NAD+ degradation in vitro and in vivo.

Unexpectedly, the reaction is stimulated by inorganic phosphate, and our data

reveal that MbcT is a NAD+ phosphorylase. In the absence of MbcA, MbcT triggers

rapid M. tuberculosis cell death, which reduces mycobacterial survival in

macrophages and prolongs the survival of infected mice. Our study expands the

molecular activities employed by bacterial TA modules and uncovers a new class of

enzymes that could be exploited to treat tuberculosis and other infectious

diseases.

Crown Copyright © 2019. Published by Elsevier Inc. All rights reserved.

DOI: 10.1016/j.molcel.2019.01.028

PMID: 30792174

6. J Exp Med. 2019 Mar 4;216(3):556-570. doi: 10.1084/jem.20181776. Epub 2019 Feb

20.

A major role for ferroptosis in Mycobacterium tuberculosis-induced cell death and

tissue necrosis.

Amaral EP(1), Costa DL(2), Namasivayam S(2), Riteau N(2)(3), Kamenyeva O(4),

Mittereder L(2), Mayer-Barber KD(5), Andrade BB(6)(7)(8)(9)(10)(11), Sher A(12).

Author information:

(1)Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of

Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD

eduardo.amaral@nih.gov.

(2)Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of

Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD.

(3)University of Orleans and CNRS, UMR7355, Orleans, France.

…

Necrotic cell death during Mycobacterium tuberculosis (Mtb) infection is

considered host detrimental since it facilitates mycobacterial spread.

Ferroptosis is a type of regulated necrosis induced by accumulation of free iron

and toxic lipid peroxides. We observed that Mtb-induced macrophage necrosis is

associated with reduced levels of glutathione and glutathione peroxidase-4

(Gpx4), along with increased free iron, mitochondrial superoxide, and lipid

peroxidation, all of which are important hallmarks of ferroptosis. Moreover,

necrotic cell death in Mtb-infected macrophage cultures was suppressed by

ferrostatin-1 (Fer-1), a well-characterized ferroptosis inhibitor, as well as by

iron chelation. Additional experiments in vivo revealed that pulmonary necrosis

in acutely infected mice is associated with reduced Gpx4 expression as well as

increased lipid peroxidation and is likewise suppressed by Fer-1 treatment.

Importantly, Fer-1-treated infected animals also exhibited marked reductions in

bacterial load. Together, these findings implicate ferroptosis as a major

mechanism of necrosis in Mtb infection and as a target for host-directed therapy

of tuberculosis.

This is a work of the U.S. Government and is not subject to copyright protection

in the United States. Foreign copyrights may apply.

DOI: 10.1084/jem.20181776

PMCID: PMC6400546 [Available on 2019-09-04]

PMID: 30787033

7. Lancet Infect Dis. 2019 Mar;19(3):298-307. doi: 10.1016/S1473-3099(18)30673-X.

Epub 2019 Feb 8.

Drug susceptibility testing and mortality in patients treated for tuberculosis in

high-burden countries: a multicentre cohort study.

Zürcher K(1), Ballif M(2), Fenner L(2), Borrell S(3), Keller PM(4), Gnokoro J(5),

Marcy O(6), Yotebieng M(7), Diero L(8), Carter EJ(8), Rockwood N(9), Wilkinson

RJ(10), Cox H(11), Ezati N(12), Abimiku AG(13), Collantes J(14), Avihingsanon

A(15), Kawkitinarong K(16), Reinhard M(3), Hömke R(4), Huebner R(17), Gagneux

S(3), Böttger EC(4), Egger M(18); International epidemiology Databases to

Evaluate AIDS (IeDEA) consortium.

Collaborators: Zürcher K, Egger M, Fenner L, Ballif M, Chammartin F, Gagneux S,

Borrell S, Reinhard M, Boettger EC, Keller P, Hömke R, Abimiku A, Ezati N,

Yotebieng M, Wenzi L, Tabala M, Cox H, Rockwood N, Warren R, Streicher E,

Wilkinson RJ, Carter EJ, Diero L, Collantes J, Zamudio C, Huebner R, Sohn A,

Avihingsanon A, Petersen T, Kawkitinarong K, Kasipong N, Gnokoro J, N'Guessan K,

Marcy O.

Author information:

(1)Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern,

Switzerland; Swiss Tropical and Public Health Institute, Basel, Switzerland;

University of Basel, Basel, Switzerland.

(2)Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern,

Switzerland.

(3)Swiss Tropical and Public Health Institute, Basel, Switzerland; University of

Basel, Basel, Switzerland.

…

BACKGROUND: Drug resistance is a challenge for the global control of

tuberculosis. We examined mortality in patients with tuberculosis from

high-burden countries, according to concordance or discordance of results from

drug susceptibility testing done locally and in a reference laboratory.

METHODS: This multicentre cohort study was done in Côte d'Ivoire, Democratic

Republic of the Congo, Kenya, Nigeria, South Africa, Peru, and Thailand. We

collected Mycobacterium tuberculosis isolates and clinical data from adult

patients aged 16 years or older. Patients were stratified by HIV status and

tuberculosis drug resistance. Molecular or phenotypic drug susceptibility testing

was done locally and at the Swiss National Center for Mycobacteria, Zurich,

Switzerland. We examined mortality during treatment according to drug

susceptibility test results and treatment adequacy in multivariable logistic

regression models adjusting for sex, age, sputum microscopy, and HIV status.

FINDINGS: We obtained M tuberculosis isolates from 871 patients diagnosed between

2013 and 2016. After exclusion of 237 patients, 634 patients with tuberculosis

were included in this analysis; the median age was 33·2 years (IQR 26·9-42·5),

239 (38%) were women, 272 (43%) were HIV-positive, and 69 (11%) patients died.

Based on the reference laboratory drug susceptibility test, 394 (62%) strains

were pan-susceptible, 45 (7%) monoresistant, 163 (26%) multidrug-resistant (MDR),

and 30 (5%) had pre-extensively or extensively drug resistant (pre-XDR or XDR)

tuberculosis. Results of reference and local laboratories were concordant for 513

(81%) of 634 patients and discordant for 121 (19%) of 634. Overall, sensitivity

to detect any resistance was 90·8% (95% CI 86·5-94·2) and specificity 84·3%

(80·3-87·7). Mortality ranged from 6% (20 of 336) in patients with

pan-susceptible tuberculosis treated according to WHO guidelines to 57% (eight of

14) in patients with resistant strains who were under-treated. In logistic

regression models, compared with concordant drug susceptibility test results, the

adjusted odds ratio of death was 7·33 (95% CI 2·70-19·95) for patients with

discordant results potentially leading to under-treatment.

INTERPRETATION: Inaccurate drug susceptibility testing by comparison with a

reference standard leads to under-treatment of drug-resistant tuberculosis and

increased mortality. Rapid molecular drug susceptibility test of first-line and

second-line drugs at diagnosis is required to improve outcomes in patients with

MDR tuberculosis and pre-XDR or XDR tuberculosis.

FUNDING: National Institutes of Allergy and Infectious Diseases, Swiss National

Science Foundation, Swiss National Center for Mycobacteria.

Copyright © 2019 Elsevier Ltd. All rights reserved.

DOI: 10.1016/S1473-3099(18)30673-X

PMID: 30744962

8. J Exp Med. 2019 Mar 4;216(3):471-473. doi: 10.1084/jem.20190038. Epub 2019 Feb

20.

Die another way: Ferroptosis drives tuberculosis pathology.

Meunier E(1), Neyrolles O(2).

Author information:

(1)Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse,

Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse,

France.

(2)Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse,

Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse,

France olivier.neyrolles@ipbs.fr.

In this issue of JEM, Amaral et al. (https://doi.org/10.1084/jem.20181776)

provide the first evidence that ferroptosis, a newly described form of regulated

cell death, is detrimental for the host during a Mycobacterium tuberculosis

infection. This finding has important implications for the development of

host-directed therapies for tuberculosis.

© 2019 Neyrolles and Meunier.

DOI: 10.1084/jem.20190038

PMCID: PMC6400539 [Available on 2019-09-04]

PMID: 30787032

9. Nat Commun. 2019 Feb 8;10(1):688. doi: 10.1038/s41467-019-08405-9.

Corticosteroids inhibit Mycobacterium tuberculosis-induced necrotic host cell

death by abrogating mitochondrial membrane permeability transition.

Gräb J(1)(2), Suárez I(1)(3), van Gumpel E(1)(2), Winter S(1)(2), Schreiber

F(1)(2), Esser A(1)(2), Hölscher C(3)(4), Fritsch M(2)(5)(6), Herb M(5)(6),

Schramm M(5)(6), Wachsmuth L(7), Pallasch C(1)(5), Pasparakis M(2)(5)(7), Kashkar

H(2)(5)(6), Rybniker J(8)(9)(10).

Author information:

(1)Department I of Internal Medicine, University of Cologne, 50937, Cologne,

Germany.

(2)Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931,

Cologne, Germany.

(3)German Center for Infection Research (DZIF), Partner Site Bonn-Cologne,

Cologne, Germany.

…

Corticosteroids are host-directed drugs with proven beneficial effect on survival

of tuberculosis (TB) patients, but their precise mechanisms of action in this

disease remain largely unknown. Here we show that corticosteroids such as

dexamethasone inhibit necrotic cell death of cells infected with Mycobacterium

tuberculosis (Mtb) by facilitating mitogen-activated protein kinase phosphatase 1

(MKP-1)-dependent dephosphorylation of p38 MAPK. Characterization of infected

mixed lineage kinase domain-like (MLKL) and tumor necrosis factor receptor 1

(TNFR1) knockout cells show that the underlying mechanism is independent from

TNFα-signaling and necroptosis. Our results link corticosteroid function and p38

MAPK inhibition to abrogation of necrotic cell death mediated by mitochondrial

membrane permeability transition, and open new avenues for research on novel

host-directed therapies (HDT).

DOI: 10.1038/s41467-019-08405-9

PMCID: PMC6368550

PMID: 30737374

10. Lancet Infect Dis. 2019 Feb;19(2):193-202. doi: 10.1016/S1473-3099(18)30613-3.

Epub 2019 Jan 14.

Clinical utility of existing and second-generation interferon-γ release assays

for diagnostic evaluation of tuberculosis: an observational cohort study.

Whitworth HS(1), Badhan A(2), Boakye AA(2), Takwoingi Y(3), Rees-Roberts M(4),

Partlett C(3), Lambie H(5), Innes J(6), Cooke G(7), Lipman M(8), Conlon C(9),

Macallan D(10), Chua F(11), Post FA(12), Wiselka M(13), Woltmann G(14), Deeks

JJ(3), Kon OM(2), Lalvani A(15); Interferon-γ Release Assays for Diagnostic

Evaluation of Active Tuberculosis study group.

Collaborators: Abdoyeku D, Davidson R, Dedicoat M, Kunst H, Loebingher MR, Lynn

W, Nathani N, O'Connell R, Pozniak A, Menzies S.

Author information:

(1)Tuberculosis Research Centre, National Heart and Lung Institute, Imperial

College London, London, UK; Department of Clinical Research, London School of

Hygiene and Tropical Medicine, London, UK.

(2)Tuberculosis Research Centre, National Heart and Lung Institute, Imperial

College London, London, UK; National Institute for Health Research Health

Protection Research Unit in Respiratory Infections, Imperial College London,

London, UK.

(3)Institute of Applied Health Research, University of Birmingham, Birmingham,

UK.

…

Erratum in

Lancet Infect Dis. 2019 Feb;19(2):e39.

Lancet Infect Dis. 2019 Mar;19(3):e64.

BACKGROUND: The clinical utility of interferon-γ release assays (IGRAs) for

diagnosis of active tuberculosis is unclear, although they are commonly used in

countries with a low incidence of tuberculosis. We aimed to resolve this clinical

uncertainty by determining the accuracy and utility of commercially available and

second-generation IGRAs in the diagnostic assessment of suspected tuberculosis in

a low-incidence setting.

METHODS: We did a prospective cohort study of adults with suspected tuberculosis

in routine secondary care in England. Patients were tested for Mycobacterium

tuberculosis infection at baseline with commercially available (T-SPOT.TB and

QuantiFERON-TB Gold In-Tube [QFT-GIT]) and second-generation (incorporating novel

M tuberculosis antigens) IGRAs and followed up for 6-12 months to establish

definitive diagnoses. Sensitivity, specificity, positive and negative likelihood

ratios, and predictive values of the tests were determined.

FINDINGS: Of the 1060 adults enrolled in the study, 845 were included in the

analyses and 363 were diagnosed with tuberculosis. Sensitivity of T-SPOT.TB for

all tuberculosis diagnosis, including culture-confirmed and highly probable

cases, was 81·4% (95% CI 76·6-85·3), which was higher than QFT-GIT (67·3%

[62·0-72·1]). Second-generation IGRAs had a sensitivity of 94·0% (90·0-96·4) for culture-confirmed tuberculosis and 89·2% (85·2-92·2) when including highly

probable tuberculosis, giving a negative likelihood ratio for all tuberculosis

cases of 0·13 (95% CI 0·10-0·19). Specificity ranged from 86·2% (95% CI

82·3-89·4) for T-SPOT.TB to 80·0% (75·6-83·8) for second-generation IGRAs.

INTERPRETATION: Commercially available IGRAs do not have sufficient accuracy for

diagnostic evaluation of suspected tuberculosis. Second-generation tests,

however, might have sufficiently high sensitivity, low negative likelihood ratio,

and correspondingly high negative predictive value in low-incidence settings to

facilitate prompt rule-out of tuberculosis.

FUNDING: National Institute for Health Research.

Copyright © 2019 Elsevier Ltd. All rights reserved.

DOI: 10.1016/S1473-3099(18)30613-3

PMID: 30655049

11. Clin Infect Dis. 2019 Feb 27. pii: ciz152. doi: 10.1093/cid/ciz152. [Epub ahead

of print]

A moxifloxacin-based regimen for the treatment of recurrent drug-sensitive

pulmonary tuberculosis: An open-label randomised controlled trial.

Perumal R(1)(2)(3), Padayatchi N(1)(3), Yende-Zuma N(1)(3), Naidoo A(1)(3),

Govender D(1)(3), Naidoo K(1)(3).

Author information:

(1)Centre for the AIDS Programme of Research in South Africa, Nelson R Mandela

School of Medicine, College of Health Sciences, University of KwaZulu-Natal.

(2)Department of Pulmonology and Critical Care, Groote Schuur Hospital,

University of Cape Town, Western Cape, South Africa.

(3)South African Medical Research Council-CAPRISA HIV-TB Pathogenesis and

Treatment Research Unit, Doris Duke Medical Research Institute, University of

KwaZulu-Natal.

BACKGROUND: The substitution of moxifloxacin for ethambutol produced promising

results for improved tuberculosis (TB) treatment outcomes.

METHOD: We conducted an open-label randomized trial to test whether a

moxifloxacin-containing treatment regimen was superior to the standard regimen

for the treatment of recurrent TB. The primary and secondary outcomes were sputum

culture conversion rate at the end of 8 weeks and the proportion of participants

with a favourable outcome, respectively.

RESULTS: We enrolled 196 participants; 69.9% were male and 70.4% were co-infected

with HIV. There was no significant difference between the study groups in the

proportion of patients achieving culture conversion at the end of 8 weeks [83.0%

(Moxifloxacin) vs 78.5% (Control), p=0.463], however the median time to culture

conversion was significantly shorter (6.0 weeks, IQR 4.0 - 8.3) in the

moxifloxacin group than the control group (7.9 weeks, IQR 4.0- 11.4) (p=0.018). A

favourable end-of-treatment outcome was reported in 86 participants (87.8%) in

the moxifloxacin group and 93 participants (94.9%) in the control group, for an

adjusted absolute risk difference of -5.5 (95% CI -13.8 to 2.8, p=0.193)

percentage points. There was a significantly higher proportion of participants

with grade 3 or 4 adverse events [43.9% (43/98) vs 25.5% (25/98), p=0.011] and

serious adverse events [27.6% (27/98) vs 12.2% (12/98), p=0.012] in the

moxifloxacin group.

CONCLUSION: Replacement of ethambutol with moxifloxacin did not significantly

improve culture conversion rates at the end of 8 weeks or treatment success, and

was associated with a higher incidence of adverse events.

© The Author(s) 2019. Published by Oxford University Press for the Infectious

Diseases Society of America. All rights reserved. For permissions, e-mail:

journals.permissions@oup.com.

DOI: 10.1093/cid/ciz152

PMID: 30809633

12. Lab Chip. 2019 Feb 25. doi: 10.1039/c8lc01404c. [Epub ahead of print]

Lab-on-a-Film disposable for genotyping multidrug-resistant Mycobacterium

tuberculosis from sputum extracts.

Kukhtin AC(1), Sebastian T(1), Golova J(1), Perov A(1), Knickerbocker C(1),

Linger Y(1), Bueno A(1), Qu P(1), Villanueva M(2), Holmberg RC(1), Chandler

DP(1), Cooney CG(1).

Author information:

(1)Akonni Biosystems, Inc., 400 Sagner Avenue, Suite 300, Frederick, MD 21701,

USA. cooney@akonni.com.

(2)Laboratorios Medicos Especializados, Ave Ejercito Nacional #6008-9, Partido

Escobedo, Cd. Juarez, CHIH 32320, Mexico.

We describe a Lab-on-a-Film disposable that detects multidrug-resistant

tuberculosis (MDR-TB) from sputum extracts. The Lab-on-a-Film disposable consists

of 203 gel elements that include DNA sequences (probes) for 37 mutations,

deletions, or insertion elements across 5 genes (including an internal control).

These gel elements are printed on a flexible film, which costs approximately 500

times less than microarray glass. The film with printed gel elements is then

laminated to additional rollable materials (films) to form a microfluidic flow

cell. We combined multiplex amplification and hybridization steps in a single

microfluidic chamber, without buffer exchanges or other manipulations up to and

throughout hybridization. This flow cell also incorporates post hybridization

wash steps while retaining an entirely closed-amplicon system, thus minimizing

the potential for sample or amplicon cross-contamination. We report analytical

sensitivity of 32 cfu mL-1 across all MDR-TB markers and detection of MDR-TB

positive clinical specimens using an automated TruTip workstation for extraction

and the Lab-on-a-Film disposable for amplification and detection of the extracts.

DOI: 10.1039/c8lc01404c

PMID: 30801596

13. J Antimicrob Chemother. 2019 Feb 21. pii: dkz048. doi: 10.1093/jac/dkz048. [Epub

ahead of print]

Rifampicin and rifabutin resistance in 1003 Mycobacterium tuberculosis clinical

isolates.

Farhat MR(1)(2), Sixsmith J(3), Calderon R(4), Hicks ND(3), Fortune SM(3), Murray

M(5)(6).

Author information:

(1)Department of Biomedical Informatics, Harvard Medical School, 10 Shattuck

Street, Boston, MA, USA.

(2)Division of Pulmonary and Critical Care, Massachusetts General Hospital, 55

Fruit Street, Boston, MA, USA.

(3)Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of

Public Health, 677 Huntington Avenue, Boston, MA, USA.

(4)Socios en Salud, Calle Los Geranios 312, Lince, Peru.

(5)Department of Global Health and Social Medicine, Harvard Medical School,

Huntington Avenue, Boston, MA, USA.

(6)Division of Global Health Equity, Brigham and Women's Hospital, 75 Francis

Street, Boston, MA, USA.

OBJECTIVES: Drug-resistant TB remains a public health challenge. Rifamycins are

among the most potent anti-TB drugs. They are known to target the RpoB subunit of

RNA polymerase; however, our understanding of how rifamycin resistance is

genetically encoded remains incomplete. Here we investigated rpoB genetic

diversity and cross-resistance between the two rifamycin drugs rifampicin and

rifabutin.

METHODS: We performed WGS of 1003 Mycobacterium tuberculosis clinical isolates

and determined MICs of both rifamycin agents on 7H10 agar using the indirect

proportion method. We generated rpoB mutants in a laboratory strain and measured

their antibiotic susceptibility using the alamarBlue reduction assay.

RESULTS: Of the 1003 isolates, 766 were rifampicin resistant and 210 (27%) of

these were rifabutin susceptible; 102/210 isolates had the rpoB mutation D435V

(Escherichia coli D516V). Isolates with discordant resistance were 17.2 times

more likely to harbour a D435V mutation than those resistant to both agents (OR

17.2, 95% CI 10.5-27.9, P value <10-40). Compared with WT, the D435V in vitro

mutant had an increased IC50 of both rifamycins; however, in both cases to a

lesser degree than the S450L (E. coli S531L) mutation.

CONCLUSIONS: The observation that the rpoB D435V mutation produces an increase in

the IC50 of both drugs contrasts with findings from previous smaller studies that

suggested that isolates with the D435V mutation remain rifabutin susceptible

despite being rifampicin resistant. Our finding thus suggests that the

recommended critical testing concentration for rifabutin should be revised.

© The Author(s) 2019. Published by Oxford University Press on behalf of the

British Society for Antimicrobial Chemotherapy. All rights reserved. For

permissions, please email: journals.permissions@oup.com.

DOI: 10.1093/jac/dkz048

PMID: 30793747

14. J Infect Dis. 2019 Feb 7. doi: 10.1093/infdis/jiy710. [Epub ahead of print]

Diverse Clinical Isolates of Mycobacterium tuberculosis Develop

Macrophage-Induced Rifampin Tolerance.

Adams KN(1), Verma AK(2), Gopalaswamy R(3), Adikesavalu H(3), Singhal DK(3),

Tripathy S(3), Ranganathan UD(3), Sherman DR(1), Urdahl KB(1), Ramakrishnan L(2),

Hernandez RE(1)(4).

Author information:

(1)Center for Global Infectious Diseases Research, Seattle Children's Research

Institute, Center for Infectious Diseases Research, Seattle, Washington.

(2)Molecular Immunity Unit, Department of Medicine, University of Cambridge,

United Kingdom.

(3)National Institute for Research in Tuberculosis, Chennai, India.

(4)Department of Pediatrics, University of Washington, Seattle, Washington.

The Mycobacterium tuberculosis lineage 4 strains CDC1551 and H37Rv develop

tolerance to multiple antibiotics upon macrophage residence. To determine whether

macrophage-induced tolerance is a general feature of clinical M. tuberculosis

isolates, we assessed macrophage-induced drug tolerance in strains from lineages

1-3, representing the other predominant M. tuberculosis strains responsible for

tuberculosis globally. All 3 lineages developed isoniazid tolerance. While

lineage 1, 3, and 4 strains developed rifampin tolerance, lineage 2 Beijing

strains did not. Their failure to develop tolerance may be explained by their

harboring of a loss-of-function mutation in the Rv1258c efflux pump that is

linked to macrophage-induced rifampicin tolerance.

DOI: 10.1093/infdis/jiy710

PMID: 30753612

15. Nanomedicine (Lond). 2019 Mar;14(6):707-726. doi: 10.2217/nnm-2018-0258. Epub

2019 Feb 8.

Matryoshka-type gastro-resistant microparticles for the oral treatment of

Mycobacterium tuberculosis.

Andreu V(1), Larrea A(1)(2), Rodriguez-Fernandez P(3)(4)(5)(6), Alfaro S(1),

Gracia B(4)(7), Lucía A(4)(7), Usón L(1)(2), Gomez AC(3)(4)(5)(6), Mendoza G(1),

Lacoma A(3)(4)(5), Dominguez J(3)(4)(5), Prat C(3)(4)(5), Sebastian V(1)(2),

Ainsa JA(4)(7), Arruebo M(1)(2).

Author information:

(1)Department of Chemical Engineering. Aragon Institute of Nanoscience (INA),

University of Zaragoza, Campus Río Ebro-Edificio I+D, C/Poeta Mariano Esquillor

S/N, Zaragoza 50018, Spain.

(2)Networking Research Center on Bioengineering, Biomaterials & Nanomedicine,

CIBER-BBN, Madrid 28029, Spain.

(3)Servei de Microbiologia, Hospital Universitari Germans Trias i Pujol, Institut

en Ciències de la Salut Germans Trias i Pujol, Badalona, Spain.

…

AIM: Production of Matryoshka-type gastroresistant microparticles containing

antibiotic-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (NP) against

Mycobacterium tuberculosis.

MATERIALS & METHODS: The emulsification and evaporation methods were followed for

the synthesis of PLGA-NPs and methacrylic acid-ethyl acrylate-based coatings to

protect rifampicin from degradation under simulated gastric conditions.

RESULTS & CONCLUSION: The inner antibiotic-loaded NPs here reported can be

released under simulated intestinal conditions whereas their coating protects

them from degradation under simulated gastric conditions. The encapsulation does

not hinder the antituberculosis action of the encapsulated antibiotic rifampicin.

A sustained antibiotic release could be obtained when using the drug-loaded

encapsulated NPs. Compared with the administration of the free drug, a more

effective elimination of M. tuberculosis was observed when applying the NPs

against infected macrophages. The antibiotic-loaded PLGA-NPs were also able to

cross an in vitro model of intestinal barrier.

DOI: 10.2217/nnm-2018-0258

PMID: 30734643

16. Proc Natl Acad Sci U S A. 2019 Feb 19;116(8):3202-3210. doi:

10.1073/pnas.1819468116. Epub 2019 Feb 5.

The Mycobacterium tuberculosis Pup-proteasome system regulates nitrate metabolism

through an essential protein quality control pathway.

Becker SH(1), Jastrab JB(1), Dhabaria A(2), Chaton CT(3), Rush JS(3), Korotkov

KV(3), Ueberheide B(2), Darwin KH(4).

Author information:

(1)Department of Microbiology, New York University School of Medicine, New York,

NY 10016.

(2)Proteomics Laboratory, Division of Advanced Research Technologies, New York

University School of Medicine, New York, NY 10016.

(3)Department of Molecular and Cellular Biochemistry, University of Kentucky,

Lexington, KY 40536.

(4)Department of Microbiology, New York University School of Medicine, New York,

NY 10016; heran.darwin@med.nyu.edu.

The human pathogen Mycobacterium tuberculosis encodes a proteasome that carries

out regulated degradation of bacterial proteins. It has been proposed that the

proteasome contributes to nitrogen metabolism in M. tuberculosis, although this

hypothesis had not been tested. Upon assessing M. tuberculosis growth in several

nitrogen sources, we found that a mutant strain lacking the Mycobacterium

proteasomal activator Mpa was unable to use nitrate as a sole nitrogen source due

to a specific failure in the pathway of nitrate reduction to ammonium. We found

that the robust activity of the nitrite reductase complex NirBD depended on

expression of the groEL/groES chaperonin genes, which are regulated by the

repressor HrcA. We identified HrcA as a likely proteasome substrate, and propose

that the degradation of HrcA is required for the full expression of chaperonin

genes. Furthermore, our data suggest that degradation of HrcA, along with

numerous other proteasome substrates, is enhanced during growth in nitrate to

facilitate the derepression of the chaperonin genes. Importantly, growth in

nitrate is an example of a specific condition that reduces the steady-state

levels of numerous proteasome substrates in M. tuberculosis.

DOI: 10.1073/pnas.1819468116

PMCID: PMC6386731 [Available on 2019-08-19]

PMID: 30723150

Conflict of interest statement: The authors declare no conflict of interest.