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Khawbung JL, Nath D, Chakraborty S. Drug resistant Tuberculosis: A review. Comp Immunol Microbiol Infect Dis 2020; 74:101574. [PMID: 33249329 DOI: 10.1016/j.cimid.2020.101574] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 11/05/2020] [Indexed: 12/14/2022]
Abstract
Tuberculosis (TB) was announced as a global emergency in 1993. There was an alarming counter attack of TB worldwide. However, when it was known that TB can be cured completely, the general public became ignorant towards the infection. The pathogenic organism Mycobacterium tuberculosis continuously evolved to resist the antagonist drugs. This has led to the outbreak of resistant strain that gave rise to "Multi Drug Resistant-Tuberculosis" and "Extensively Drug Resistant Tuberculosis" that can still be cured with a lower success rate. While the mechanism of resistance proceeds further, it ultimately causes unmanageable totally drug resistant TB (TDR-TB). Studying the molecular mechanisms underlying the resistance to drugs would help us grasp the genetics and pathophysiology of the disease. In this review, we present the molecular mechanisms behind Mycobacterium tolerance to drugs and their approach towards the development of multi-drug resistant, extremely drug resistant and totally drug resistant TB.
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Affiliation(s)
| | - Durbba Nath
- Department of Biotechnology, Assam University, Silchar, 788011, Assam, India
| | - Supriyo Chakraborty
- Department of Biotechnology, Assam University, Silchar, 788011, Assam, India.
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Prasad R, Singh A, Balasubramanian V, Gupta N. Extensively drug-resistant tuberculosis in India: Current evidence on diagnosis & management. Indian J Med Res 2018; 145:271-293. [PMID: 28749390 PMCID: PMC5555056 DOI: 10.4103/ijmr.ijmr_177_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Emergence of extensively drug-resistant tuberculosis (XDR-TB) has significantly threatened to jeopardize global efforts to control TB, especially in HIV endemic regions. XDR-TB is mainly an iatrogenically created issue, and understanding the epidemiological and risk factors associated with it is of paramount importance in curbing this menace. Emergence of this deadly phenomenon can be prevented by prompt diagnosis and effective treatment with second-line drugs in rifampicin-resistant TB (RR-TB) as well as multidrug-resistant TB (MDR-TB) patients. Optimal treatment of RR-TB, MDR-TB and XDR-TB cases alone will not suffice to reduce the global burden. The TB control programmes need to prioritize on policies focusing on the effective as well as rational use of first-line drugs in every newly diagnosed drug susceptible TB patients so as to prevent the emergence of drug resistance.
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Affiliation(s)
- Rajendra Prasad
- Department of Pulmonary Medicine, Vallabhbhai Patel Chest Institute, University of Delhi, New Delhi, India
| | - Abhijeet Singh
- Department of Pulmonary Medicine, Vallabhbhai Patel Chest Institute, University of Delhi, New Delhi, India
| | | | - Nikhil Gupta
- Department of Medicine, Era's Medical College, Lucknow, India
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Pharmacokinetic Evaluation of Sulfamethoxazole at 800 Milligrams Once Daily in the Treatment of Tuberculosis. Antimicrob Agents Chemother 2016; 60:3942-7. [PMID: 27067336 DOI: 10.1128/aac.02175-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 04/08/2016] [Indexed: 11/20/2022] Open
Abstract
For treatment of multidrug-resistant tuberculosis (MDR-TB), there is a scarcity of antituberculosis drugs. Co-trimoxazole is one of the available drug candidates, and it is already frequently coprescribed for TB-HIV-coinfected patients. However, only limited data are available on the pharmacokinetic (PK) and pharmacodynamic (PD) parameters of co-trimoxazole in TB patients. The objective of this study was to evaluate the PK parameters and in vitro PD data on the effective part of co-trimoxazole: sulfamethoxazole. In a prospective PK study in patients infected with drug-susceptible Mycobacterium tuberculosis (drug-susceptible TB patients) (age, >18), sulfamethoxazole-trimethoprim (SXT) was administered orally at a dose of 960 mg once daily. One-compartment population pharmacokinetic modeling was performed using MW\Pharm 3.81 (Mediware, Groningen, The Netherlands). The area under the concentration-time curve for the free, unbound fraction of a drug (ƒAUC)/MIC ratio and the period in which the free concentration exceeded the MIC (fT > MIC) were calculated. Twelve patients received 960 mg co-trimoxazole in addition to first-line drugs. The pharmacokinetic parameters of the population model were as follows (geometric mean ± standard deviation [SD]): metabolic clearance (CLm), 1.57 ± 3.71 liters/h; volume of distribution (V), 0.30 ± 0.05 liters · kg lean body mass(-1); drug clearance/creatinine clearance ratio (fr), 0.02 ± 0.13; gamma distribution rate constant (ktr_po), 2.18 ± 1.14; gamma distribution shape factor (n_po), 2.15 ± 0.39. The free fraction of sulfamethoxazole was 0.3, but ranged between 0.2 and 0.4. The median value of the MICs was 9.5 mg/liter (interquartile range [IQR], 4.75 to 9.5), and that of theƒAUC/MIC ratio was 14.3 (IQR, 13.0 to 17.5). The percentage of ƒT > MIC ranged between 43 and 100% of the dosing interval. The PK and PD data from this study are useful to explore a future dosing regimen of co-trimoxazole for MDR-TB treatment. (This study has been registered at ClinicalTrials.gov under registration no. NCT01832987.).
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Donald PR, Diacon AH. Para-aminosalicylic acid: the return of an old friend. THE LANCET. INFECTIOUS DISEASES 2015; 15:1091-1099. [DOI: 10.1016/s1473-3099(15)00263-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 02/09/2015] [Accepted: 02/24/2015] [Indexed: 10/23/2022]
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Pechalrieu D, Lopez M. Compounds for use in the treatment of mycobacterial infections: a patent evaluation (WO2014049107A1). Expert Opin Ther Pat 2015; 25:729-35. [PMID: 25752488 DOI: 10.1517/13543776.2015.1021333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Tuberculosis is one of the main causes of mortality with 1.5 million deaths a year worldwide. The growing emergence of multi- and extremely resistant strains highlights the urgent need of novel antibiotic strategies. Ethionamide, interfering with the mycobacterial membrane biosynthesis, is used in second-line treatment. This molecule is a prodrug, which requires activation by EthA. The patent described in this evaluation (WO2014049107A1) claimed a new family of molecules and their use as antibiotic treatment against mycobacteria such as Mycobacterium tuberculosis, M. leprae and atypical mycobacteria, either as a single active agent or in combination with antibiotics activable by EthA pathway.
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Affiliation(s)
- Dany Pechalrieu
- Unité de Service et de Recherche CNRS - Pierre Fabre n°3388 ETaC - Epigenetic Targeting of Cancer , CRDPF, 3 avenue Hubert Curien, 31035 Toulouse Cedex 01 , France
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Park CS, Seo KW, Park CR, Nah YW, Suh JH. Case of bronchoesophageal fistula with gastric perforation due to multidrug-resistant tuberculosis. World J Gastrointest Surg 2014; 6:253-8. [PMID: 25548611 PMCID: PMC4278148 DOI: 10.4240/wjgs.v6.i12.253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/08/2012] [Accepted: 03/20/2013] [Indexed: 02/06/2023] Open
Abstract
Gastric perforation and tuberculous bronchoesophageal fistula (TBEF) are very rare complications of extrapulmonary tuberculosis (TB). We present a case of pulmonary TB with TBEF and gastric perforation caused by a multidrug-resistant tuberculosis strain in a non-acquired immune deficiency syndrome male patient. The patient underwent total gastrectomy with Roux-en-Y end-to-side esophagojejunostomy and feeding jejunostomy during intravenous treatment with anti-TB medication, and esophageal reconstruction with colonic interposition and jejunocolostomy were performed successfully after a full course of anti-TB medication. Though recent therapies for TBEF have favored medication, patients with severe stenosis or perforation require surgery and medication with anti-TB drugs based upon adequate culture and drug susceptibility testing.
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Affiliation(s)
- Chan Sung Park
- Chan Sung Park, Kwang won Seo, Department of Internal medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan 682-714, South Korea
| | - Kwang Won Seo
- Chan Sung Park, Kwang won Seo, Department of Internal medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan 682-714, South Korea
| | - Chang Ryul Park
- Chan Sung Park, Kwang won Seo, Department of Internal medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan 682-714, South Korea
| | - Yang Won Nah
- Chan Sung Park, Kwang won Seo, Department of Internal medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan 682-714, South Korea
| | - Jae Hee Suh
- Chan Sung Park, Kwang won Seo, Department of Internal medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan 682-714, South Korea
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Current status and future trends in the diagnosis and treatment of drug-susceptible and multidrug-resistant tuberculosis. J Infect Public Health 2013; 7:75-91. [PMID: 24216518 DOI: 10.1016/j.jiph.2013.09.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 08/29/2013] [Accepted: 09/18/2013] [Indexed: 11/21/2022] Open
Abstract
The global burden of tuberculosis (TB) is still large. The increasing incidence of drug-resistant, multidrug-resistant (MDR) (resistant to at least rifampicin and isoniazid), and extensively drug-resistant (XDR) (additionally resistant to a fluoroquinolone and kanamycin/amikacin/capreomycin) strains of Mycobacterium tuberculosis and the association of active disease with human immunodeficiency virus coinfection pose a major threat to TB control efforts. The rapid detection of M. tuberculosis strains and drug susceptibility testing (DST) for anti-TB drugs ensure the provision of effective treatment. Rapid molecular diagnostic and DST methods have been developed recently. Treatment of drug-susceptible TB is effective in ≥95% of disease cases; however, supervised therapy for ≥6 months is challenging. Non-adherence to treatment often results in the evolution of drug-resistant strains of M. tuberculosis due to mutations in the genes encoding drug targets. Sequential accumulation of mutations results in the evolution of MDR and XDR strains of M. tuberculosis. Effective treatment of MDR-TB involves therapy with 5-7 less effective, expensive, and toxic second-line and third-line drugs for ≥24 months and is difficult in most developing countries. XDR-TB is generally an untreatable disease in developing countries. Some currently existing drugs and several new drugs with novel modes of action are in various stages of development to shorten the treatment duration of drug-susceptible TB and to improve the outcome of MDR-TB and XDR-TB.
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Ascenzi P, Coletta A, Cao Y, Trezza V, Leboffe L, Fanali G, Fasano M, Pesce A, Ciaccio C, Marini S, Coletta M. Isoniazid inhibits the heme-based reactivity of Mycobacterium tuberculosis truncated hemoglobin N. PLoS One 2013; 8:e69762. [PMID: 23936350 PMCID: PMC3731299 DOI: 10.1371/journal.pone.0069762] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 06/12/2013] [Indexed: 11/19/2022] Open
Abstract
Isoniazid represents a first-line anti-tuberculosis medication in prevention and treatment. This prodrug is activated by a mycobacterial catalase-peroxidase enzyme called KatG in Mycobacterium tuberculosis), thereby inhibiting the synthesis of mycolic acid, required for the mycobacterial cell wall. Moreover, isoniazid activation by KatG produces some radical species (e.g., nitrogen monoxide), that display anti-mycobacterial activity. Remarkably, the ability of mycobacteria to persist in vivo in the presence of reactive nitrogen and oxygen species implies the presence in these bacteria of (pseudo-)enzymatic detoxification systems, including truncated hemoglobins (trHbs). Here, we report that isoniazid binds reversibly to ferric and ferrous M. tuberculosis trHb type N (or group I; Mt-trHbN(III) and Mt-trHbN(II), respectively) with a simple bimolecular process, which perturbs the heme-based spectroscopic properties. Values of thermodynamic and kinetic parameters for isoniazid binding to Mt-trHbN(III) and Mt-trHbN(II) are K = (1.1±0.1)×10−4 M, kon = (5.3±0.6)×103 M−1 s−1 and koff = (4.6±0.5)×10−1 s−1; and D = (1.2±0.2)×10−3 M, don = (1.3±0.4)×103 M−1 s−1, and doff = 1.5±0.4 s−1, respectively, at pH 7.0 and 20.0°C. Accordingly, isoniazid inhibits competitively azide binding to Mt-trHbN(III) and Mt-trHbN(III)-catalyzed peroxynitrite isomerization. Moreover, isoniazid inhibits Mt-trHbN(II) oxygenation and carbonylation. Although the structure of the Mt-trHbN-isoniazid complex is not available, here we show by docking simulation that isoniazid binding to the heme-Fe atom indeed may take place. These data suggest a direct role of isoniazid to impair fundamental functions of mycobacteria, e.g. scavenging of reactive nitrogen and oxygen species, and metabolism.
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Affiliation(s)
- Paolo Ascenzi
- Interdepartmental Laboratory of Electron Microscopy, University Roma Tre, Roma, Italy.
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Morris MD, Quezada L, Bhat P, Moser K, Smith J, Perez H, Laniado-Laborin R, Estrada-Guzman J, Rodwell TC. Social, economic, and psychological impacts of MDR-TB treatment in Tijuana, Mexico: a patient's perspective. Int J Tuberc Lung Dis 2013; 17:954-60. [PMID: 23743315 PMCID: PMC3769163 DOI: 10.5588/ijtld.12.0480] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING The State of Baja California, Mexico, had the highest prevalence of multidrug-resistant tuberculosis (MDR-TB) in Mexico in 2009. OBJECTIVE To understand the socio-economic burden of MDR-TB disease and its treatment on patients in Tijuana and Mexicali, Mexico. DESIGN From July to November 2009, qualitative interviews were conducted with 12 patients enrolled in a US-Mexico binational MDR-TB treatment program, Puentes de Esperanza (Bridges of Hope), which was designed to support MDR-TB patients. In-depth interviews were coded to identify major themes in patient experiences of MDR-TB diagnosis and care. RESULTS While some patients were able to maintain their pre-MDR-TB lives to a limited extent, most patients reported losing their sense of identity due to their inability to work, social isolation, and stigmatization from family and friends. The majority of participants expressed appreciation for Puentes' role in 'saving their lives'. CONCLUSION Being diagnosed with MDR-TB and undergoing treatment imposes significant psychological, social and economic stress on patients. Strong social support elements within Puentes helped alleviate these burdens. Improvements to the program might include peer-support groups for patients undergoing treatment and transitioning back into the community after treatment.
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Affiliation(s)
- Meghan D. Morris
- Division of Global Public Health, Department of Medicine, University of California San Diego
| | - Liliana Quezada
- Division of Global Public Health, Department of Medicine, University of California San Diego
| | - Priya Bhat
- Division of Global Public Health, Department of Medicine, University of California San Diego
| | - Kathleen Moser
- San Diego County Tuberculosis Control Program, San Diego, CA USA
| | - Jennifer Smith
- Border Infectious Disease Surveillance Program, California Department of Public Health, San Diego, CA
| | - Hector Perez
- San Diego County Tuberculosis Control Program, San Diego, CA USA
| | | | | | - Timothy C. Rodwell
- Division of Global Public Health, Department of Medicine, University of California San Diego
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Ettehad D, Schaaf HS, Seddon JA, Cooke GS, Ford N. Treatment outcomes for children with multidrug-resistant tuberculosis: a systematic review and meta-analysis. THE LANCET. INFECTIOUS DISEASES 2012; 12:449-56. [DOI: 10.1016/s1473-3099(12)70033-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Flipo M, Desroses M, Lecat-Guillet N, Villemagne B, Blondiaux N, Leroux F, Piveteau C, Mathys V, Flament MP, Siepmann J, Villeret V, Wohlkönig A, Wintjens R, Soror SH, Christophe T, Jeon HK, Locht C, Brodin P, Déprez B, Baulard AR, Willand N. Ethionamide boosters. 2. Combining bioisosteric replacement and structure-based drug design to solve pharmacokinetic issues in a series of potent 1,2,4-oxadiazole EthR inhibitors. J Med Chem 2011; 55:68-83. [PMID: 22098589 DOI: 10.1021/jm200825u] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mycobacterial transcriptional repressor EthR controls the expression of EthA, the bacterial monooxygenase activating ethionamide, and is thus largely responsible for the low sensitivity of the human pathogen Mycobacterium tuberculosis to this antibiotic. We recently reported structure-activity relationships of a series of 1,2,4-oxadiazole EthR inhibitors leading to the discovery of potent ethionamide boosters. Despite high metabolic stability, pharmacokinetic evaluation revealed poor mice exposure; therefore, a second phase of optimization was required. Herein a structure-property relationship study is reported according to the replacement of the two aromatic heterocycles: 2-thienyl and 1,2,4-oxadiazolyl moieties. This work was done using a combination of structure-based drug design and in vitro/ex vivo evaluations of ethionamide boosters on the targeted protein EthR and on the human pathogen Mycobacterium tuberculosis. Thanks to this process, we identified compound 42 (BDM41906), which displays improved efficacy in addition to high exposure to mice after oral administration.
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Affiliation(s)
- Marion Flipo
- Université Lille Nord de France, F-59000 Lille, France
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Zellweger JP. [Multidrug resistant tuberculosis -- its extent, hazard and possible solutions]. Rev Mal Respir 2011; 28:1025-33. [PMID: 22099408 DOI: 10.1016/j.rmr.2010.10.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 10/22/2010] [Indexed: 11/17/2022]
Abstract
Multidrug resistant tuberculosis (MDR-TB) has spread to most regions of the world and represents a serious threat to the success of the struggle against tuberculosis. It can result from errors in management that favour the selection of drug resistant organisms and can in the worst case lead to the development of extremely resistant organisms (XDR-TB) which are practically untreatable. The current strategies for combating this problem are, on the one hand, the rapid identification and tracking of resistant strains using molecular genetic techniques and, on the other hand, careful drug management in individual cases using second line agents. At the level of public health, the most important measures are those which prevent or correct the processes which can drive the creation of new cases of MDR-TB. This can have implications for the modification and development of national strategies. The future of the fight against tuberculosis depends in part on the success of strategies to combat the development and spread of MDR-TB.
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Affiliation(s)
- J-P Zellweger
- Centre de Compétence Tuberculose, Ligue Pulmonaire Suisse, 14c, Südbahnhofstrasse, 3000 Berne 14, Suisse.
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Notari S, Mancone C, Sergi M, Gullotta F, Bevilacqua N, Tempestilli M, Urso R, Lauria FN, Pucillo LP, Tripodi M, Ascenzi P. Determination of antituberculosis drug concentration in human plasma by MALDI-TOF/TOF. IUBMB Life 2010; 62:387-93. [PMID: 20306514 DOI: 10.1002/iub.321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Therapeutic drug monitoring allows to determine the best dosage regimen adapted to each patient optimizing the therapeutic benefits, while minimizing the risk for side effects. Here, the first methodological approach based on matrix-assisted laser desorption/ionization source equipped with tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry for the determination of the antituberculosis (anti-TB) drugs ethambutol, pyrazinamide, rifampicin, and streptomycin concentration in the plasma of tuberculosis-infected patients is reported. The volume of the plasma sample was 200 microL. Plasma samples were cleaned-up by protein precipitation and evaporated in a water bath under a nitrogen stream. The extracted samples were reconstituted with 200 microL of 50% methanol-0.03% formic acid solution (v/v), spiked with known amounts of anti-TB drugs, mixed (1:1) with a saturated matrix solution (4-hydroxybenzoic acid in 50% acetonitrile-0.1% trifluoracetic acid solution; v/v), and spotted onto the MALDI-TOF/TOF sample target plate. The anti-TB drug concentration was determined by standard additions analysis. Regression of standard additions was linear over the whole anti-TB drug concentration range explored (the final anti-TB drug concentration ranged from 0.20 to 200 pmol/microL). The absolute recovery of the anti-TB drugs ranged between 87 and 110%. The minimal ethambutol, pyrazinamide, rifampicin, and streptomycin concentration detectable by MALDI-TOF/TOF is 0.08, 0.20, 0.12, and 0.15 pmol/microL, respectively.
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Affiliation(s)
- Stefania Notari
- Istituto Nazionale per le Malattie Infettive I.R.C.C.S. Lazzaro Spallanzani, Roma, Italy
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Ahmad S, Mokaddas E. Recent advances in the diagnosis and treatment of multidrug-resistant tuberculosis. Respir Med 2009; 103:1777-90. [PMID: 19660927 DOI: 10.1016/j.rmed.2009.07.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 06/18/2009] [Accepted: 07/19/2009] [Indexed: 11/28/2022]
Abstract
Tuberculosis (TB) is a major infectious disease killing nearly two million people, mostly in developing countries, every year. The increasing incidence of resistance of Mycobacterium tuberculosis strains to the most-effective (first-line) anti-TB drugs is a major factor contributing to the current TB epidemic. Drug-resistant strains have evolved mainly due to incomplete or improper treatment of TB patients. Resistance of M. tuberculosis to anti-TB drugs is caused by chromosomal mutations in genes encoding drug targets. Multidrug-resistant (resistant at least to rifampin and isoniazid) strains of M. tuberculosis (MDR-TB) evolve due to sequential accumulation of mutations in target genes. Emergence and spreading of MDR-TB strains is hampering efforts for the control and management of TB. The MDR-TB is also threatening World Health Organization's target of tuberculosis elimination by 2050. Proper management of MDR-TB relies on early recognition of such patients. Several diagnostic methods, both phenotypic and molecular, have been developed recently for rapid identification of MDR-TB strains from suspected patients and some are also suitable for resource-poor countries. Once identified, successful treatment of MDR-TB requires therapy with several effective drugs some of which are highly toxic, less efficacious and expensive. Minimum treatment duration of 18-24 months is also long, making it difficult for health care providers to ensure adherence to treatment. Successful treatment has been achieved by supervised therapy with appropriate drugs at institutions equipped with facilities for culture, drug susceptibility testing of MDR-TB strains to second-line drugs and regular monitoring of patients for adverse drug reactions and bacteriological and clinical improvement.
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Affiliation(s)
- Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait.
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Dye C. Doomsday postponed? Preventing and reversing epidemics of drug-resistant tuberculosis. Nat Rev Microbiol 2009; 7:81-7. [PMID: 19079354 DOI: 10.1038/nrmicro2048] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis, now known to be present in 50 countries, heighten the threat posed by untreatable and fatal human tuberculosis (TB). To combat epidemics of drug-resistant TB, it is vital to understand why some resistant strains have greater reproductive fitness--a greater propensity to spread--than drug-susceptible strains. If public health malpractice has been a more important determinant of reproductive success than genetic mechanisms, then improved diagnosis and treatment could keep the frequency of resistant strains among TB cases low in any population. Recent data suggest that national TB control programmes that use existing drugs efficiently can postpone and even reverse epidemics of multidrug-resistant TB, although the effect of such programmes on XDR strains remains largely unknown.
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Jassal M, Bishai WR. Extensively drug-resistant tuberculosis. THE LANCET. INFECTIOUS DISEASES 2009; 9:19-30. [DOI: 10.1016/s1473-3099(08)70260-3] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Méndez-Samperio P. Role of antimicrobial peptides in host defense against mycobacterial infections. Peptides 2008; 29:1836-41. [PMID: 18582513 DOI: 10.1016/j.peptides.2008.05.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 05/28/2008] [Accepted: 05/30/2008] [Indexed: 11/28/2022]
Abstract
Worldwide, tuberculosis remains the most important infectious disease causing morbidity and death. Currently, at least one-third of the world's population is infected with Mycobacterium tuberculosis. In addition, the World Health Organization estimates that about 8-10 million new tuberculosis cases occur annually worldwide and this incidence is currently increasing. Moreover, multidrug-resistant tuberculosis has been increasing in incidence in many areas during the past decade. These situations underscore the importance of the development of new therapeutic agents against mycobacterial infectious diseases. In this article, it is review current progress in the understanding of antimicrobial peptides as potential candidates to develop an alternative/adjunct therapeutic strategy against tuberculosis. This immunoadjunctive therapy might be evaluated in the context of possible drug resistance. This review also summarizes the knowledge about the functions of antimicrobial peptides in the pulmonary innate host defense system and their role in mycobacterial infection, and at the same time outlines recent advances in our understanding of the combined effect of antimicrobial peptides and anti-tuberculosis drugs against intracellular mycobacteria. A concerted effort should now focus on the clinical application of antimicrobial peptides for their practical use.
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Affiliation(s)
- Patricia Méndez-Samperio
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, México, D.F. 11340, Mexico.
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Mitnick CD, Appleton SC, Shin SS. Epidemiology and treatment of multidrug resistant tuberculosis. Semin Respir Crit Care Med 2008; 29:499-524. [PMID: 18810684 DOI: 10.1055/s-0028-1085702] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Multidrug resistant tuberculosis is now thought to afflict between 1 and 2 million patients annually. Although significant regional variability in the distribution of disease has been recorded, surveillance data are limited by several factors. The true burden of disease is likely underestimated. Nevertheless, the estimated burden is substantial enough to warrant concerted action. A range of approaches is possible, but all appropriate interventions require scale-up of laboratories and early treatment with regimens containing a sufficient number of second-line drugs. Ambulatory treatment for most patients, and improved infection control, can facilitate scale-up with decreased risk of nosocomial transmission. Several obstacles have been considered to preclude worldwide scale-up of treatment, mostly attributable to inadequate human, drug, and financial resources. Further delays in scale-up, however, risk continued generation and transmission of resistant tuberculosis, as well as associated morbidity and mortality.
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Affiliation(s)
- Carole D Mitnick
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts 02199, USA.
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Bicmen C, Gunduz A, Coskun M, Senol G, Ozkutuk N, Cirak A, Ozacar R. Molecular identification and characterization of rifampicin-resistantMycobacterium tuberculosisisolates by line probe assay: an approach for rapid diagnosis of multidrug-resistant tuberculosis. Lett Appl Microbiol 2008; 47:214-20. [DOI: 10.1111/j.1472-765x.2008.02403.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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