scholarly journals Host Directed Therapies for Tuberculosis: Futures Strategies for an Ancient Disease

Chemotherapy ◽  
2018 ◽  
Vol 63 (3) ◽  
pp. 172-180 ◽  
Author(s):  
Ivana Palucci ◽  
Giovanni Delogu
Keyword(s):  
New Drugs ◽  
Drug Resistant ◽  
Mdr Tb ◽  
Promising Area ◽  
Global Threat ◽  
New Treatments ◽  
The Cost ◽  
Length Of Therapy ◽  
Drug Resistant Strains ◽  
Combination Regimens

The emergence and spread of drug-resistant strains of Mycobacterium tuberculosis is worsening the global threat of tuberculosis (TB). There is a need and urgency for the development of new treatments for TB, for the management of drug resistant TB (MDR-TB) and for improved regimens against drug-susceptible TB, with the goal of reducing toxicity and length of therapy that will boost patience compliance. The paucity of new drugs is a major obstacle to design new regimens while host-directed therapies (HDTs) are emerging as a promising area of research and are opening new avenues to fight TB. In this review, we discuss examples of potentially promising strategies aimed at improving the host response to M. tuberculosis, and argue how a better understanding of TB pathogenesis, with the fine characterization of the immunological mediators involved, may pave the way for the design of new therapies, the identification of new drugs or the repurposing of some already in use for other diseases. We emphasize that any HDTs shall be included as adjunct therapy to the drug-combination regimens already in use for TB, with the goal to reduce tissue damage and immunopathology and enhance bacterial clearance. We anticipate that the benefits of HDTs against TB will be highest against MDR-TB, where the activity of current regimens is poor and the cost high.

Management of Multidrug-Resistant Tuberculosis

2018 ◽  
Vol 39 (03) ◽  
pp. 310-324 ◽  
Author(s):  
Jose Caminero ◽  
Charles Daley
Keyword(s):  
Multidrug Resistant ◽  
New Drugs ◽  
World Health ◽  
Drug Resistant ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb ◽  
Resistant Strains ◽  
Health Organization ◽  
Drug Resistant Strains

AbstractDrug-resistant strains of Mycobacterium tuberculosis pose a major threat to global tuberculosis control. Despite the availability of curative antituberculosis therapy for nearly half a century, inappropriate and inadequate treatment of tuberculosis, as well as unchecked transmission of M. tuberculosis, has resulted in alarming levels of drug-resistant tuberculosis. The World Health Organization (WHO) estimates that there were 600,000 cases of multidrug-resistant tuberculosis (MDR-TB)/rifampin-resistant (RR) tuberculosis in 2016, defined as strains that are resistant to at least isoniazid and rifampicin. Globally, WHO estimates that 4.1% of new tuberculosis cases and 19% of retreatment cases have MDR-TB. By the end of 2016, 123 countries had reported at least one case of extensively drug-resistant strains, which are MDR-TB strains that have acquired additional resistance to fluoroquinolones and at least one second-line injectable. It is estimated that only 22% of all MDR-TB cases are currently receiving therapy. This article reviews the management of MDR/RR-TB and updates recommendations regarding the use of shorter course regimens and new drugs.

scholarly journals Identification of drug candidates that enhance pyrazinamide activity from a clinical drug library

2017 ◽  
Author(s):  
Hongxia Niu ◽  
Chao Ma ◽  
Peng Cui ◽  
Wanliang Shi ◽  
Shuo Zhang ◽  
...  
Keyword(s):  
Treatment Time ◽  
New Drugs ◽  
Prolonged Treatment ◽  
Drug Resistant ◽  
Drug Candidates ◽  
Resistant Tuberculosis ◽  
Multi Drug Resistant Tuberculosis ◽  
Mdr Tb ◽  
Drug Resistant Strains ◽  
Clinical Drug

Tuberculosis (TB) remains a leading cause of morbidity and mortality globally despite the availability of the TB therapy. 1 The current TB therapy is lengthy and suboptimal, requiring a treatment time of at least 6 months for drug susceptible TB and 9-12 months (shorter Bangladesh regimen) or 18-24 months (regular regimen) for multi-drug-resistant tuberculosis (MDR-TB). 1 The lengthy therapy makes patient compliance difficult, which frequently leads to emergence of drug-resistant strains. The requirement for the prolonged treatment is thought to be due to dormant persister bacteria which are not effectively killed by the current TB drugs, except rifampin and pyrazinamide (PZA) which have higher activity against persisters. 2, 3 Therefore new therapies should address the problem of insufficient efficacy against M. tuberculosis persisters, which could cause relapse of clinical disease. 4 PZA is a critical frontline TB drug that kills persister bacteria 5 and shortens the TB treatment from 9-12 months to 6 months. 6, 7 Although several new TB drugs are showing promise in clinical studies, none can replace PZA as they all have to be used together with PZA. 7 Because of the essentiality of PZA and the high cost of developing new drugs, in this study, we explored the idea of identifying drugs that enhance the anti-persister activity of PZA as an economic alternative approach to developing new drugs for improved treatment by screening an clinical drug library against old M. tuberculosis cultures enriched with persisters.

scholarly journals TB Elimination Requires Discovery and Development of Transformational Agents

2020 ◽  
Vol 10 (7) ◽  
pp. 2605 ◽  
Author(s):  
Christian Lienhardt ◽  
Mario C. Raviglione
Keyword(s):  
Rapid Detection ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
New Drugs ◽  
World Health ◽  
Drug Resistant ◽  
The World ◽  
Health Organization ◽  
Combination Regimens

The World Health Organization (WHO) End Tuberculosis (TB) Strategy has set ambitious targets to reduce 2015 TB incidence and deaths by 80% and 90%, respectively, by the year 2030. Given the current rate of TB incidence decline (about 2% per year annually), reaching these targets will require new transformational tools and innovative ways to deliver them. In addition to improved tests for early and rapid detection of TB and universal drug-susceptibility testing, as well as novel vaccines for improved prevention, better, safer, shorter and more efficacious treatments for all forms of TB are needed. Only a handful of new drugs are currently in phase II or III clinical trials, and a few combination regimens are being tested, mainly for drug-resistant TB. In this article, capitalising on an increasingly rich medicine pipeline and taking advantage of new methodological designs with great potential, the main areas where progress is needed for a transformational improvement of treatment of all forms of TB are described.

Antituberculosis activities of clofazimine and its new analogs B4154 and B4157.

1996 ◽  
Vol 40 (3) ◽  
pp. 633-636 ◽  
Author(s):  
V M Reddy ◽  
G Nadadhur ◽  
D Daneluzzi ◽  
J F O'Sullivan ◽  
P R Gangadharam
Keyword(s):  
Multidrug Resistant ◽  
New Drugs ◽  
Drug Resistant ◽  
Antituberculosis Drugs ◽  
Resistant Tuberculosis ◽  
Chemotherapeutic Activity ◽  
Resistant Strains ◽  
Intracellular Activities ◽  
Moderate Resistance ◽  
Drug Resistant Strains

In our efforts to develop new drugs for the treatment of tuberculosis, especially that caused by multidrug-resistant strains, we investigated clofazimine (CFM) and two of its analogs, B4154 and B4157, for their antituberculosis activities. Twenty M. tuberculosis strains were tested, including 16 drug-resistant strains (strains resistant to one or more antituberculosis drugs), for their susceptibilities to these three agents. All of the strains were found to be susceptible to B4154 and B4157, and one strain showed moderate resistance to CFM. The MICs of B4154, B4157, and CFM at which 90% of strains were inhibited were 0.25, 0.12, and < or = 1.0 microgram/ml, respectively. The intracellular activities of CFM and B4157 were superior to that of B4154. The chemotherapeutic activities of the three compounds were evaluated in C57BL/6 mice. At a dose of 20 mg/kg of body weight, the activity of CFM was slightly superior to that of B4157; however, both compounds prevented mortality and caused a significant reduction in the numbers of CFU in the lungs and spleens. The animals treated with B4157 showed less pigmentation than animals treated with CFM. The chemotherapeutic activity of CFM was comparable to those of rifampin and isoniazid. Complete susceptibility of multidrug-resistant strains to CFM and B4157 and the therapeutic efficacies of these compounds against mouse tuberculosis make these drugs attractive agents for the treatment of drug-resistant tuberculosis.

scholarly journals Multidrug-Resistant Tuberculosis in Alberta and British Columbia, 1989 to 1998

1999 ◽  
Vol 6 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Ahmed Hersi ◽  
Kevin Elwood ◽  
Robert Cowie ◽  
Dennis Kunimoto ◽  
Richard Long
Keyword(s):  
British Columbia ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Foreign Born ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Culture Positive

OBJECTIVE: To describe the extent of the problem of multidrug-resistant tuberculosis (MDR-TB) in Alberta and British Columbia from 1989 to 1998.DESIGN: A retrospective, population-based descriptive study of all notified MDR-TB cases in the context of all notified TB cases, all notified culture-positive TB cases and all notified drug-resistant TB cases.SETTING: Provinces of Alberta and British Columbia, and their TB registries.PATIENTS: All people with TB reported to the TB registries of Alberta and British Columbia between January 1, 1989 and June 30, 1998.MAIN OUTCOME MEASURES: Drug susceptibility testing was performed in all cases of culture-positive TB. Demographic, clinical and laboratory data on all cases of MDR-TB were recorded.RESULTS: Of 4606 notified cases of TB, 3553 (77.1%) were culture positive. Of these, 365 (10.3%) were drug resistant; of the drug-resistant cases, 24 (6.6%) were MDR. Most MDR-TB patients were foreign-born; of the four Canadian-born patients, two were infected while travelling abroad. Although foreign-born patients were significantly more likely to harbour drug-resistant strains, 14.3% versus 4.8%, respectively (P<0.001), among those who were harbouring a drug-resistant strain, the proportion of Canadian-born versus foreign-born patients with an MDR strain was the same (6.7% versus 6.6%, respectively). From 1994 to 1998 versus 1989 to 1993, the proportion of all drug-resistant strains that were MDR was greater (9.0% versus 4.3%, respectively), but the difference was not statistically significant. Isolates from 16 of the 24 MDR-TB cases had been archived. Each of these was fingerprinted and found to be unique. Most MDR-TB cases (88%) were respiratory. Of those tested for human immunodeficiency virus (n=17), only one was seropositive. MDR-TB was ‘acquired’ in 67% and ‘primary’ in 33% of cases. Eight (33%) of the MDR-TB cases received curative courses of treatment, six (25%) are still being treated, and the remainder have either died (five, 21%), transferred out (four, 17%) or become ‘chronic’ (one, 4%). No secondary case of MDR-TB has been identified in Alberta and British Columbia.CONCLUSIONS: Most MDR-TB in Alberta and British Columbia is imported. The proportion of all drug-resistant cases that are MDR appears to be increasing, but not because of disease acquired from recent contact with MDR-TB in Canada.

Anti-mycobacterial Constituents from Medicinal Plants; A Review

2021 ◽  
Vol 21 ◽  
Author(s):  
Nandan Sarkar ◽  
Yadu Nandan Dey ◽  
Dharmendra Kumar ◽  
Mogana R
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Medicinal Plants ◽  
Development Process ◽  
Multidrug Resistant ◽  
Review Article ◽  
New Drugs ◽  
Drug Resistant ◽  
Drug Discovery And Development ◽  
Resistant Strains ◽  
Drug Resistant Strains

: Effective treatment of tuberculosis has been hindered by the emergence of drug-resistant strains of Mycobacterium therapeutic facilities tuberculosis. With the global resurgence of tuberculosis with the development of multidrug-resistant cases, there is a call for the development of new drugs to combat these diseases. Throughout history, natural products have afforded a rich source of compounds that have found many applications in the fields of medicine, pharmacy and biology, and continued to play a significant role in the drug discovery and development process. This review article depicts the various potential plant extracts as well as plant-derived phytoconstituents against the H37rv, the most persistent strains of Mycobacterium tuberculosis and its multidrug strains.

scholarly journals Regimens to treat multidrug-resistant tuberculosis: past, present and future perspectives

2019 ◽  
Vol 28 (152) ◽  
pp. 190035 ◽  
Author(s):  
Emanuele Pontali ◽  
Mario C. Raviglione ◽  
Giovanni Battista Migliori
Keyword(s):  
Multidrug Resistant ◽  
New Drugs ◽  
World Health ◽  
Drug Resistant ◽  
Optimal Outcomes ◽  
Resistant Tuberculosis ◽  
Prolonged Duration ◽  
Mdr Tb ◽  
Revised Definitions ◽  
Health Organization

Over the past few decades, treatment of multidrug-resistant (MDR)/extensively drug-resistant (XDR) tuberculosis (TB) has been challenging because of its prolonged duration (up to 20–24 months), toxicity, costs and sub-optimal outcomes.After over 40 years of neglect, two new drugs (bedaquiline and delamanid) have been made available to manage difficult-to-treat MDR-/XDR-TB cases. World Health Organization (WHO) guidelines published in March 2019 endorsed the possibility of treating MDR-TB patients with a full oral regimen, following previous guidelines published in 2016 which launched a shorter regimen lasting 9–10 months.The objectives of this article are to review the main achievements in MDR-TB treatment through the description of the existing WHO strategies, to discuss the main ongoing trials and to shed light on potential future scenarios and revised definitions necessary to manage drug-resistant TB.

scholarly journals Treatment of Multidrug-Resistant and Extensively Drug-Resistant Tuberculosis in Children: The Role of Bedaquiline and Delamanid

2021 ◽  
Vol 9 (5) ◽  
pp. 1074
Author(s):  
Francesco Pecora ◽  
Giulia Dal Canto ◽  
Piero Veronese ◽  
Susanna Esposito
Keyword(s):  
Adverse Effects ◽  
Pediatric Population ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Drug Resistant ◽  
Standard Regimen ◽  
Drug Resistant Tuberculosis ◽  
Resistant Tuberculosis ◽  
Extensively Drug Resistant ◽  
Mdr Tb

Multidrug-resistant (MDR) tuberculosis (TB) has been emerging at an alarming rate over the last few years. It has been estimated that about 3% of all pediatric TB is MDR, meaning about 30,000 cases each year. Although most children with MDR-TB can be successfully treated, up to five years ago effective treatment was associated with a high incidence of severe adverse effects and patients with extensively drug-resistant (XDR) TB had limited treatment options and no standard regimen. The main objective of this manuscript is to discuss our present knowledge of the management of MDR- and XDR-TB in children, focusing on the characteristics and available evidence on the use of two promising new drugs: bedaquiline and delamanid. PubMed was used to search for all of the studies published up to November 2020 using key words such as “bedaquiline” and “delamanid” and “children” and “multidrug-resistant tuberculosis” and “extensively drug-resistant tuberculosis”. The search was limited to articles published in English and providing evidence-based data. Although data on pediatric population are limited and more studies are needed to confirm the efficacy and safety of bedaquiline and delamanid, their use in children with MDR-TB/XDR-TB appears to have good tolerability and efficacy. However, more evidence on these new anti-TB drugs is needed to better guide their use in children in order to design effective shorter regimens and reduce adverse effects, drug interactions, and therapeutic failure.

scholarly journals Effectiveness and safety of delamanid- or bedaquiline-containing regimens among children and adolescents with multidrug resistant or extensively drug resistant tuberculosis: A nationwide study from Belarus, 2015-19

2021 ◽  
Vol 91 (1) ◽  
Author(s):  
Varvara Solodovnikova ◽  
Ajay M.V. Kumar ◽  
Hennadz Hurevich ◽  
Yuliia Sereda ◽  
Vera Auchynka ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Multidrug Resistant ◽  
Post Treatment ◽  
New Drugs ◽  
Drug Resistant ◽  
Drug Resistant Tuberculosis ◽  
Resistant Tuberculosis ◽  
Extensively Drug Resistant ◽  
Mdr Tb ◽  
Culture Conversion

There is limited evidence describing the safety and effectiveness of bedaquiline and delamanid containing regimens in children and adolescents with Multidrug-Resistant Tuberculosis (MDR-TB) and Extensively Drug-Resistant Tuberculosis (XDR-TB) globally. In this nationwide descriptive cohort study from Belarus, we examined adverse drug events, time to culture conversion, treatment outcomes including post-treatment recurrence among children and adolescents (<18 years of age) treated with bedaquiline and/or delamanid containing regimens from 2015 to 2019. Of the 40 participants included (55% females; age range 10-17 years), 20 (50%) had XDR-TB and 15 (38%) had resistance to either fluoroquinolone or second-line injectable. Half of the patients received delamanid and another half received bedaquiline with one patient receiving both drugs. AEs were reported in all the patients. A total of 224 AEs were reported, most of which (76%) were mild in nature. Only 10 (5%) AEs were graded severe and one AE was graded life-threatening. A total of 7 AEs (3%) were classified as ‘serious’ and only one patient required permanent discontinuation of the suspected drug (linezolid). Most of the AEs (94%) were resolved before the end of treatment. All patients culture-positive at baseline (n=34) became culture-negative within three months of treatment. Median time to culture conversion was 1.1 months (interquartile range: 0.9-1.6). Two patients were still receiving treatment at the time of analysis. The remaining 38 patients successfully completed treatment. Among those eligible and assessed at 6 (n=32) and 12 months (n=27) post-treatment, no recurrences were detected. In conclusion, treatment of children and adolescents with MDR-TB and XDR-TB using bedaquiline and/or delamanid containing regimens was effective and had favourable safety profile. Achieving such excellent outcomes under programmatic settings is encouraging for other national tuberculosis programmes, which are in the process of introducing or scaling-up the use of these new drugs in their countries.

scholarly journals Utilisation of the Prestwick Chemical Library®to identify drugs that inhibit the growth of Mycobacteria

2018 ◽  
Author(s):  
Panchali Kanvatirth ◽  
Rose E. Jeeves ◽  
Joanna Bacon ◽  
Gurdyal S. Besra ◽  
Luke J. Alderwick
Keyword(s):  
Drug Repurposing ◽  
Antimycobacterial Activity ◽  
Drug Regimen ◽  
New Drugs ◽  
Bacterial Disease ◽  
Drug Resistant ◽  
Chemical Library ◽  
Incidence And Mortality ◽  
Approved Drugs ◽  
New Treatments

AbstractTuberculosis (TB) is an infectious bacterial disease that kills approximately 1.3 million people every year. Despite global efforts to reduce both the incidence and mortality associated with TB, the emergence of drug resistant strains has slowed any progress made towards combating the spread of this deadly disease. The current TB drug regimen is inadequate, takes months to complete and poses significant challenges when administering to patients suffering from drug resistant TB. New treatments that are faster, simpler and more affordable are urgently required. Arguably, a good strategy to discover new drugs is to start with an old drug. Here, we have screened a library of 1200 FDA approved drugs from the Prestwick Chemical library®using a GFP microplate assay. Drugs were screened against GFP expressing strains ofMycobacterium smegmatisandMycobacterium bovisBCG as surrogates forMycobacterium tuberculosis,the causative agent of TB in humans. We identified several classes of drugs that displayed antimycobacterial activity against bothM. smegmatisandM. bovisBCG, however each organism also displayed some selectivity towards certain drug classes. Variant analysis of whole genomes sequenced for resistant mutants raised to florfenicol, vanoxerine and pentamidine highlight new pathways that could be exploited in drug repurposing programmes.

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