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Hou K, Jabeen R, Sun L, Wei J. How do Mutations of Mycobacterium Genes Cause Drug Resistance in Tuberculosis? Curr Pharm Biotechnol 2024; 25:724-736. [PMID: 37888812 DOI: 10.2174/0113892010257816230920053547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/28/2023] [Accepted: 08/07/2023] [Indexed: 10/28/2023]
Abstract
A steady increase in the prevalence of drug-resistant tuberculosis (DR-TB) has already been reported in Pakistan. In addition, DR-TB is gradually changing from one-drug resistance to multi-drug resistance, which is a serious challenge for tuberculosis treatment. This review provides an overview of the anti-tuberculosis drugs and focuses on the molecular mechanisms of drug resistance in Mycobacterium tuberculosis, with the hope that it will contribute to the study of drug resistance in response to the emergence of multidrug-resistant tuberculosis.
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Affiliation(s)
- Kaiying Hou
- School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Riffat Jabeen
- School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Lin Sun
- College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, China
| | - Jianshe Wei
- School of Life Sciences, Henan University, Kaifeng, 475004, China
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Mittal P, Ajmera P, Jain V, Aggarwal G. Modeling and analysis of barriers in controlling TB: developing countries' perspective. INTERNATIONAL JOURNAL OF HEALTH GOVERNANCE 2021. [DOI: 10.1108/ijhg-06-2021-0060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PurposeTuberculosis (TB) continues to c-exist with humans despite many TB control programs and elimination strategies. This depicts that some barriers are not allowing achieving the desired results. The current study aims to focus on identification and ranking of such barriers to facilitate TB control programs in developing countries.Design/methodology/approachIn the present study, 13 barriers that can influence success rate of TB elimination strategies have been recognized with an in-depth assessment of related literature and opinions of specialists from medical industry and academic world. The interpretive structural modeling (ISM) and decision-making trial and evaluation laboratory (DEMATEL) techniques have been employed for the ranking of barriers.FindingsBased on driving power of barriers, the study coined that underinvestment is a major barrier followed by poor implementation of government policies and programs, poverty and poor primary health care infrastructure.Research limitations/implicationsThe findings may guide healthcare service providers and researchers in analyzing the barriers and understanding the necessity of further advancements to decrease the count of already existing and incident cases.Practical implicationsPolicy- and decision-makers may utilize the information on dependence and driving power of barriers for better planning and effective execution of TB control strategies.Originality/valueAlthough a lot of literature is available on different barriers that are affecting success of TB strategies, the current study analyzes all the key barriers collectively for the prioritization of barriers.
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Cruz JN, Costa JFS, Khayat AS, Kuca K, Barros CAL, Neto AMJC. Molecular dynamics simulation and binding free energy studies of novel leads belonging to the benzofuran class inhibitors of Mycobacterium tuberculosis Polyketide Synthase 13. J Biomol Struct Dyn 2018; 37:1616-1627. [PMID: 29633908 DOI: 10.1080/07391102.2018.1462734] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In this work, the binding mechanism of new Polyketide Synthase 13 (Pks13) inhibitors has been studied through molecular dynamics simulation and free energy calculations. The drug Tam1 and its analogs, belonging to the benzofuran class, were submitted to 100 ns simulations, and according to the results obtained for root mean square deviation, all the simulations converged from approximately 30 ns. For the analysis of backbone flotation, the root mean square fluctuations were plotted for the Cα atoms; analysis revealed that the greatest fluctuation occurred in the residues that are part of the protein lid domain. The binding free energy value (ΔGbind) obtained for the Tam16 lead molecule was of -51.43 kcal/mol. When comparing this result with the ΔGbind values for the remaining analogs, the drug Tam16 was found to be the highest ranked: this result is in agreement with the experimental results obtained by Aggarwal and collaborators, where it was verified that the IC50 for Tam16 is the smallest necessary to inhibit the Pks13 (IC50 = 0.19 μM). The energy decomposition analysis suggested that the residues which most interact with inhibitors are: Ser1636, Tyr1637, Asn1640, Ala1667, Phe1670, and Tyr1674, from which the greatest energy contribution to Phe1670 was particularly notable. For the lead molecule Tam16, a hydrogen bond with the hydroxyl of the phenol not observed in the other analogs induced a more stable molecular structure. Aggarwal and colleagues reported this hydrogen bonding as being responsible for the stability of the molecule, optimizing its physic-chemical, toxicological, and pharmacokinetic properties.
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Key Words
- CNPq, National Council for Scientific and Technological Development
- CoA, coenzyme A
- FAS, fatty acid synthase
- GAFF, general amber force field
- GB, generalized born
- HB, hydrogen bonds
- INH, isoniazid
- KatG, catalase-peroxidase
- MD, molecular dynamics
- MDR, multi-drug resistant
- MM/GBSA, molecular mechanics/generalized-born surface area
- NAD, nicotinamide adenine dinucleotide
- NS, nanoseconds
- PCA, acyl carrier protein
- Pks13
- Pks13, polyketide synthase 13
- RESP, restrained electrostatic potential
- RMSD, root mean square deviation
- RMSF, root mean square fluctuations
- TB, tuberculosis
- TE, C-terminal thioesterase
- XDR, extensively drug resistant
- benzofuran
- free energy
- inhibitors
- molecular dynamics
- Δ internal energy
- Δ, Van Der Waals contributions
- Δ, electrostatic contribution
- Δ, electrostatic contributions
- Δ, energy of desolvation
- Δ, energy of the molecular mechanics
- Δ, non-polar contributions
- Δ, polar contributions
- Δ, polar solvation contribution
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Affiliation(s)
- Jorddy N Cruz
- a Laboratory of Preparation and Computation of Nanomaterials , Federal University of Pará , CP 479, 66075-110 Belém , PA , Brazil
| | - José F S Costa
- a Laboratory of Preparation and Computation of Nanomaterials , Federal University of Pará , CP 479, 66075-110 Belém , PA , Brazil
| | - André S Khayat
- b Oncology Research Center , Federal University of Pará , CP 479, 6675-105 Belém , PA , Brazil
| | - Kamil Kuca
- c Biomedical Research Center , University Hospital Hradec Kralove , Sokolska 581, 500 05 Hradec Kralove , Czech Republic
| | - Carlos A L Barros
- d Department of Pharmacy , Federal University of Pará , CP 479, 66050-160 Belém , PA , Brazil
| | - A M J C Neto
- a Laboratory of Preparation and Computation of Nanomaterials , Federal University of Pará , CP 479, 66075-110 Belém , PA , Brazil
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Asante-Poku A, Otchere ID, Danso E, Mensah DD, Bonsu F, Gagneux S, Yeboah-Manu D. Evaluation of GenoType MTBDRplus for the rapid detection of drug-resistant tuberculosis in Ghana. Int J Tuberc Lung Dis 2016; 19:954-959. [PMID: 26162362 DOI: 10.5588/ijtld.14.0864] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rapid but simple diagnostic tools for the detection of drug-resistant (DR) tuberculosis (TB) have been acknowledged as being important for its effective management and control. OBJECTIVE To establish a molecular line-probe assay (GenoType MTBDRplus) for detecting DR-TB in Ghana. METHOD We first screened 113 Mycobacterium tuberculosis isolates using the indirect proportion method and MTBDRplus. The rpoB and katG genes and the promoter regions of oxyR-ahpC and inhA were sequenced to identify mutations in isolates found to be resistant on phenotypic drug susceptibility testing and/or MTBDRplus. We then analysed an additional 412 isolates using only MTBDRplus. RESULTS Respectively 43 (8.2%) and 8 (1.5%) isolates were resistant to isoniazid (INH) and rifampicin (RMP), while 8 (1.5%) were multidrug-resistant. In resistant isolates, mutations in codon 450 of rpoB and codon 315 of katG, conferring resistance to respectively RMP and INH, dominated. We found two RMP-resistant isolates with a S450L substitution, each harbouring an additional mutation at S388L and Q409R. Using phenotypic testing as gold standard, the MTBDRplus assay showed a sensitivity and specificity in the detection of RMP and INH resistance and multidrug resistance of respectively 100% and 100%, 83.3% and 100%, and 100% and 100%. CONCLUSION The high sensitivity of MTBDRplus makes it a valuable addition to the conventional TB diagnostic algorithm in Ghana.
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Affiliation(s)
- Adwoa Asante-Poku
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.,Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Isaac Darko Otchere
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Emelia Danso
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - David Delali Mensah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Frank Bonsu
- National Tuberculosis Control Program, Ghana Health Service
| | - Sebastien Gagneux
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Dorothy Yeboah-Manu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
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Guardia A, Gulten G, Fernandez R, Gómez J, Wang F, Convery M, Blanco D, Martínez M, Pérez-Herrán E, Alonso M, Ortega F, Rullás J, Calvo D, Mata L, Young R, Sacchettini JC, Mendoza-Losana A, Remuiñán M, Ballell Pages L, Castro-Pichel J. N-Benzyl-4-((heteroaryl)methyl)benzamides: A New Class of Direct NADH-Dependent 2-trans Enoyl-Acyl Carrier Protein Reductase (InhA) Inhibitors with Antitubercular Activity. ChemMedChem 2016; 11:687-701. [PMID: 26934341 DOI: 10.1002/cmdc.201600020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/12/2016] [Indexed: 12/14/2022]
Abstract
Isoniazid (INH) remains one of the cornerstones of antitubercular chemotherapy for drug-sensitive strains of M. tuberculosis bacteria. However, the increasing prevalence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains containing mutations in the KatG enzyme, which is responsible for the activation of INH into its antitubercular form, have rendered this drug of little or no use in many cases of drug-resistant tuberculosis. Presented herein is a novel family of antitubercular direct NADH-dependent 2-trans enoyl-acyl carrier protein reductase (InhA) inhibitors based on an N-benzyl-4-((heteroaryl)methyl)benzamide template; unlike INH, these do not require prior activation by KatG. Given their direct InhA target engagement, these compounds should be able to circumvent KatG-related resistance in the clinic. The lead molecules were shown to be potent inhibitors of InhA and showed activity against M. tuberculosis bacteria. This new family of inhibitors was found to be chemically tractable, as exemplified by the facile synthesis of analogues and the establishment of structure-activity relationships. Furthermore, a co-crystal structure of the initial hit with the enzyme is disclosed, providing valuable information toward the design of new InhA inhibitors for the treatment of MDR/XDR tuberculosis.
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Affiliation(s)
- Ana Guardia
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain.
| | - Gulcin Gulten
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard College Station, TX, 77843-2128, USA
| | - Raquel Fernandez
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Jesus Gómez
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Feng Wang
- California Institute for Biomedical Research (Calibr), 11119 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Maire Convery
- Molecular Discovery Research, GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Delia Blanco
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - María Martínez
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Esther Pérez-Herrán
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Marta Alonso
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Fátima Ortega
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Joaquín Rullás
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - David Calvo
- Centro de Investigación Básica, Platform Technologies and Science, GlaxoSmithKline, Parque Tecnológico de Madrid, 28760 Tres Cantos, Madrid, Spain
| | - Lydia Mata
- Centro de Investigación Básica, Platform Technologies and Science, GlaxoSmithKline, Parque Tecnológico de Madrid, 28760 Tres Cantos, Madrid, Spain
| | - Robert Young
- Molecular Discovery Research, GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - James C Sacchettini
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard College Station, TX, 77843-2128, USA
| | - Alfonso Mendoza-Losana
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Modesto Remuiñán
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Lluís Ballell Pages
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Julia Castro-Pichel
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
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Hu Y, Mathema B, Zhao Q, Chen L, Lu W, Wang W, Kreiswirth B, Xu B. Acquisition of second-line drug resistance and extensive drug resistance during recent transmission of Mycobacterium tuberculosis in rural China. Clin Microbiol Infect 2015; 21:1093.e9-1093.e18. [PMID: 26348262 DOI: 10.1016/j.cmi.2015.08.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 08/10/2015] [Accepted: 08/27/2015] [Indexed: 11/17/2022]
Abstract
Multidrug-resistant tuberculosis (MDR-TB) is prevalent in countries with a high TB burden, like China. As little is known about the emergence and spread of second-line drug (SLD) -resistant TB, we investigate the emergence and transmission of SLD-resistant Mycobacterium tuberculosis in rural China. In a multi-centre population-based study, we described the bacterial population structure and the transmission characteristics of SLD-resistant TB using Spoligotyping in combination with genotyping based on 24-locus MIRU-VNTR (mycobacterial interspersed repetitive unit-variable-number tandem repeat) plus four highly variable loci for the Beijing family, in four rural Chinese regions with diverse geographic and socio-demographic characteristics. Transmission networks among genotypically clustered patients were constructed using social network analysis. Of 1332 M. tuberculosis patient isolates recovered, the Beijing family represented 74.8% of all isolates and an association with MDR and simultaneous resistance between first-line drugs and SLDs. The genotyping analysis revealed that 189 isolates shared MIRU-VNTR patterns in 78 clusters with clustering rate and recent transmission rate of 14.2% and 8.3%, respectively. Fifty-three SLD-resistant isolates were observed in 31 clusters, 30 of which contained the strains with different drug susceptibility profiles and genetic mutations. In conjunction with molecular data, socio-network analysis indicated a key role of Central Township in the transmission across a highly interconnected network where SLD resistance accumulation occurred during transmission. SLD-resistant M. tuberculosis has been spreading in rural China with Beijing family being the dominant strains. Primary transmission of SLD-resistant strains in the population highlights the importance of routine drug susceptibility testing and effective anti-tuberculosis regimens for drug-resistant TB.
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Affiliation(s)
- Y Hu
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety (Fudan University), Ministry of Education, China
| | - B Mathema
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA; Tuberculosis Center, Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Q Zhao
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety (Fudan University), Ministry of Education, China
| | - L Chen
- Tuberculosis Center, Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - W Lu
- Department of Chronic Infectious Diseases, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, China
| | - W Wang
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety (Fudan University), Ministry of Education, China
| | - B Kreiswirth
- Tuberculosis Center, Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - B Xu
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety (Fudan University), Ministry of Education, China.
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Pal S, Singh G, Singh S, Tripathi JK, Ghosh JK, Sinha S, Ampapathi RS, Chakraborty TK. Tetrahydrofuran amino acid-containing gramicidin S analogues with improved biological profiles. Org Biomol Chem 2015; 13:6789-802. [DOI: 10.1039/c5ob00622h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Replacement of thed-Phe-Pro units of GS with novel C6-Bn-substituted tetrahydrofuran amino acid minimized its cytotoxicity while preserving its antimicrobial activity, with a few analogs showing selective anti-TB activity as well.
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Affiliation(s)
- Sudip Pal
- Medicinal and Process Chemistry Division
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
| | - Gajendra Singh
- Centre for Nuclear Magnetic Resonance
- SAIF
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
| | - Shyam Singh
- Biochemistry Division
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
| | - Jitendra Kumar Tripathi
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
| | - Jimut Kanti Ghosh
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
| | - Sudhir Sinha
- Biochemistry Division
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
| | - Ravi Sankar Ampapathi
- Centre for Nuclear Magnetic Resonance
- SAIF
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
| | - Tushar Kanti Chakraborty
- Medicinal and Process Chemistry Division
- CSIR-Central Drug Research Institute
- Lucknow-226031
- India
- Department of Organic Chemistry
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8
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Manning T, Mikula R, Lee H, Calvin A, Darrah J, Wylie G, Phillips D, Bythell BJ. The copper (II) ion as a carrier for the antibiotic capreomycin against Mycobacterium tuberculosis. Bioorg Med Chem Lett 2014; 24:976-82. [DOI: 10.1016/j.bmcl.2013.12.053] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 12/11/2013] [Accepted: 12/12/2013] [Indexed: 12/30/2022]
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Abstract
Bacterial resistance to antibacterial drugs has been increasing relentlessly over the past two decades. This includes common residents of the human body: Staphylococcus aureus (methicillin resistant or MRSA) Enteroccus faecalis and E. faecium (vancomycin resistant or VRE): Enterobacteriaceae (multiresistant, carbapenems included or CRE). It also includes environmental, opportunistic, but intrinsically multiresistant species: Pseudomonas aeruginosa and Acinetobacter baumannii. Financial considerations have curtailed R&D activity in the antibacterial field in all, but a couple of large pharmaceutical companies and small biotech companies have largely been unable to fill the drug discovery gap. Antibacterials currently under development have targeted, almost exclusively, Gram-positive bacteria; hence, greater effort must be directed against Gram-negative bacteria, particularly enterobacteria. There also has to be more transparency and care in clinical development. To get ahead of the problem of resistance, we must look for first-in-class antibacterials and new targets. The need to innovate is best addressed through partnerships between drug-makers and public institutions. Such partnerships would provide a long-term view and stability to projects, but also balance the interests of corporate and public stakeholders.
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Jennings BC, Labby KJ, Green KD, Garneau-Tsodikova S. Redesign of substrate specificity and identification of the aminoglycoside binding residues of Eis from Mycobacterium tuberculosis. Biochemistry 2013; 52:5125-32. [PMID: 23837529 DOI: 10.1021/bi4002985] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The upsurge in drug-resistant tuberculosis (TB) is an emerging global problem. The increased expression of the enhanced intracellular survival (Eis) protein is responsible for the clinical resistance to aminoglycoside (AG) antibiotics of Mycobacterium tuberculosis . Eis from M. tuberculosis (Eis_Mtb) and M. smegmatis (Eis_Msm) function as acetyltransferases capable of acetylating multiple amines of many AGs; however, these Eis homologues differ in AG substrate preference and in the number of acetylated amine groups per AG. The AG binding cavity of Eis_Mtb is divided into two narrow channels, whereas Eis_Msm contains one large cavity. Five bulky residues lining one of the AG binding channels of Eis_Mtb, His119, Ile268, Trp289, Gln291, and Glu401, have significantly smaller counterparts in Eis_Msm, Thr119, Gly266, Ala287, Ala289, and Gly401, respectively. To identify the residue(s) responsible for AG binding in Eis_Mtb and for the functional differences from Eis_Msm, we have generated single, double, triple, quadruple, and quintuple mutants of these residues in Eis_Mtb by mutating them into their Eis_Msm counterparts, and we tested their acetylation activity with three structurally diverse AGs: kanamycin A (KAN), paromomyin (PAR), and apramycin (APR). We show that penultimate C-terminal residue Glu401 plays a critical role in the overall activity of Eis_Mtb. We also demonstrate that the identities of residues Ile268, Trp289, and Gln291 (in Eis_Mtb nomenclature) dictate the differences between the acetylation efficiencies of Eis_Mtb and Eis_Msm for KAN and PAR. Finally, we show that the mutation of Trp289 in Eis_Mtb into Ala plays a role in APR acetylation.
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Affiliation(s)
- Benjamin C Jennings
- Life Sciences Institute, 210 Washtenaw Avenue, University of Michigan, Ann Arbor, Michigan 48109-2216, United States
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11
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Inhibition of Mycobacterium tuberculosis strains H37Rv and MDR MS-115 by a new set of C5 modified pyrimidine nucleosides. Bioorg Med Chem 2013; 21:4874-84. [PMID: 23891229 DOI: 10.1016/j.bmc.2013.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 06/26/2013] [Accepted: 07/01/2013] [Indexed: 11/24/2022]
Abstract
Two sets of pyrimidine nucleoside derivatives bearing extended alkyloxymethyl or alkyltriazolidomethyl substituents at position 5 of the nucleobase were synthesized and evaluated as potential antituberculosis agents. The impact of modifications at 3'- and 5'-positions of the carbohydrate moiety on the antimycobacterial activity and cytotoxicity was studied. The highest effect was shown for 5-dodecyloxymethyl-2'-deoxyuridine, 5-decyltriazolidomethyl-2'-deoxyuridine, and 5-dodecyltriazolidomethyl-2'-deoxycytidine. They effectively inhibited the growth of two Mycobacterium tuberculosis strains in vitro, laboratory H37Rv (MIC99=20, 10, and 20μg/mL, respectively) and clinical MDR MS-115 resistant to five top antituberculosis drugs (МIC99=50, 10, and 10μg/mL, respectively).
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12
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Evaluation of MGIT 960 System for the Second-Line Drugs Susceptibility Testing of Mycobacterium tuberculosis. Tuberc Res Treat 2013; 2013:108401. [PMID: 23606961 PMCID: PMC3628654 DOI: 10.1155/2013/108401] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 03/07/2013] [Accepted: 03/11/2013] [Indexed: 11/17/2022] Open
Abstract
Many laboratories validate DST of the second-line drugs by BACTEC MGIT 960 system. The objective of this study is to evaluate the critical concentration and perform DST for the 2nd line drugs. We evaluated 193 clinical strains of M. tuberculosis isolated from patients in South Korea. Testing the critical concentration of six second-line drugs was performed by MGIT 960 and compared with L-J proportion method. The critical concentration was determined to establish the most one that gave the difference between drug resistance and susceptibility in MGIT960 system. Good agreement of the following concentrations was found: Concordance was 95% for 0.5 μg/mL of moxifloxacin; 93.6%, 1.0 μg/mL of levofloxacin; 97.5%, 2.5 μg/mL of kanamycin; 90.6%, 2.5 μg/mL of capreomycin; 86.2%, 5.0 μg/mL of ethionamide; and 90.8%, 2.0 μg/mL of ρ-aminosalicylic acid. The critical concentrations of the four drugs, moxifloxacin, levofloxacin, kanamycin, and capreomycin, were concordant and reliable for testing 2nd line drug resistance. Further study of ethionamide and ρ-aminosalicylic acid is required.
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Porco TC, Gao D, Scott JC, Shim E, Enanoria WT, Galvani AP, Lietman TM. When does overuse of antibiotics become a tragedy of the commons? PLoS One 2012; 7:e46505. [PMID: 23236344 PMCID: PMC3517551 DOI: 10.1371/journal.pone.0046505] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 08/31/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Over-prescribing of antibiotics is considered to result in increased morbidity and mortality from drug-resistant organisms. A resulting common wisdom is that it would be better for society if physicians would restrain their prescription of antibiotics. In this view, self-interest and societal interest are at odds, making antibiotic use a classic "tragedy of the commons". METHODS AND FINDINGS We developed two mathematical models of transmission of antibiotic resistance, featuring de novo development of resistance and transmission of resistant organisms. We analyzed the decision to prescribe antibiotics as a mathematical game, by analyzing individual incentives and community outcomes. CONCLUSIONS A conflict of interest may indeed result, though not in all cases. Increased use of antibiotics by individuals benefits society under certain circumstances, despite the amplification of drug-resistant strains or organisms. In situations where increased use of antibiotics leads to less favorable outcomes for society, antibiotics may be harmful for the individual as well. For other scenarios, where a conflict between self-interest and society exists, restricting antibody use would benefit society. Thus, a case-by-case assessment of appropriate use of antibiotics may be warranted.
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Affiliation(s)
- Travis C. Porco
- Francis I. Proctor Foundation for Research in Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, United States of America
- Center for Infectious Disease and Emergency Readiness, University of California, Berkeley, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - Daozhou Gao
- Francis I. Proctor Foundation for Research in Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - James C. Scott
- Department of Mathematics and Statistics, Colby College, Waterville, Maine, United States of America
| | - Eunha Shim
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Wayne T. Enanoria
- Francis I. Proctor Foundation for Research in Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- Center for Infectious Disease and Emergency Readiness, University of California, Berkeley, California, United States of America
| | - Alison P. Galvani
- School of Medicine, Yale University, New Haven, Connecticut, United States of America
| | - Thomas M. Lietman
- Francis I. Proctor Foundation for Research in Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- Institute for Global Health, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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14
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Characterization of extensively drug-resistant Mycobacterium tuberculosis in Nepal. Tuberculosis (Edinb) 2012; 93:84-8. [PMID: 23146281 DOI: 10.1016/j.tube.2012.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 10/12/2012] [Accepted: 10/15/2012] [Indexed: 11/21/2022]
Abstract
The emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised public health concern for global control of TB. Although molecular characterization of drug resistance-associated mutations in multidrug-resistant isolates in Nepal has been made, mutations in XDR isolates and their genotypes have not been reported previously. In this study, we identified and characterized 13 XDR Mycobacterium tuberculosis isolates from clinical isolates in Nepal. The most prevalent mutations involved in rifampicin, isoniazid, ofloxacin, and kanamycin/capreomycin resistance were Ser531Leu in rpoB gene (92.3%), Ser315Thr in katG gene (92.3%), Asp94Gly in gyrA gene (53.9%) and A1400G in rrs gene (61.5%), respectively. Spoligotyping and multilocus sequence typing revealed that 69% belonged to Beijing family, especially modern types. Further typing with 26-loci variable number of tandem repeats suggested the current spread of XDR M. tuberculosis. Our result highlights the need to reinforce the TB policy in Nepal with regard to control and detection strategies.
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15
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Frequency of extensively drug-resistant tuberculosis (XDR-TB) among re-treatment cases in NIDCH, Dhaka, Bangladesh. J Infect Chemother 2012; 19:243-8. [PMID: 23053506 DOI: 10.1007/s10156-012-0490-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 09/20/2012] [Indexed: 10/27/2022]
Abstract
Emergence of extensively drug-resistant (XDR) tuberculosis (TB) in Bangladesh has increased as a result of the inadequate management of TB-infected individuals. The present study attempted to detect the frequency of multidrug resistance (MDR) among the TB patients categorically from relapse, category I failure, category II failure, and return after default category I and II cases, using the conventional drug susceptibility test. Among 100 sputum specimens from all four categories, 81 and 84 positive cases were identified under light-emitting diode fluorescence microscope and the Lowenstein-Jensen (L-J) culture method, respectively. Of 84 culture-positive cases, elevated resistance was observed against isoniazid (89.3 %) and rifampicin (91.7 %) compared to that against streptomycin (53.6 %) and ethambutol (47.7 %). Resistance against ofloxacin, gatifloxacin, and kanamycin was 8.3, 5.9, and 2.4 %, consecutively. Fifty-nine cases were found to be MDR-TB. Two of these cases, which showed resistance against kanamycin and ofloxacin, were further identified as XDR. The proportion of XDR cases was more likely to be in the return after default category I and II cases.
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16
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Zhang J, Mi L, Wang Y, Liu P, Liang H, Huang Y, Lv B, Yuan L. Genotypes and drug susceptibility of Mycobacterium tuberculosis Isolates in Shihezi, Xinjiang Province, China. BMC Res Notes 2012; 5:309. [PMID: 22713520 PMCID: PMC3441358 DOI: 10.1186/1756-0500-5-309] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 06/14/2012] [Indexed: 11/30/2022] Open
Abstract
Background Tuberculosis (TB) remains a major global health problem. To investigate the genotypes of Mycobacterium tuberculosis (MTB) and the distribution of Beijing family strains, molecular epidemiology technologies have been used widely. Methods From June 2010 to June 2011, 55 M. tuberculosis isolates from patients with pulmonary TB were studied by Beijing family-specific PCR (detection of the deletion of region of difference 105 [RD105]), and mycobacterial interspersed repetitive units variable number tandem repeat (MIRU-VNTR) analysis. Twenty-four MIRU-VNTR loci defined the genotypes and clustering characteristics of the local strains. All strains were subjected to a drug susceptibility test (DST) by the proportion method on Lowenstein-Jensen (LJ) culture media. Results Fifty-five clinical isolates of MTB were collected. Beijing family strains represented 85.5% of the isolates studied. Using 24 loci MIRU-VNTR typing categorized the strains into eight gene groups, 46 genotypes, and seven clusters. 83.6% (46/55) of the isolates belonged to the largest gene group. Thirty-six isolates (65.5%) were susceptible, nineteen (34.5%) were resistant to at least one drug, seven (12.8%) were Multidrug-Resistant Tuberculosis (MDR TB), and two (3.6%) were extremely drug-resistant tuberculosis (XDR-TB). Conclusion The results showed there were obvious polymorphisms of VNTRs of MTB clinical strains. Beijing family strains of MTB were predominant in the Shihezi region of Xinjiang province. There was no correlation between the drug-resistance and Beijing family strains of MTB. It is necessary to strengthen the monitoring, treatment, and management of drug-resistance TB in Shihezi region, Xinjiang.
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Affiliation(s)
- Juan Zhang
- Department of Pathogenic Biology and Immunology, School of Medicine, Shi Hezi University, Shihezi, People's Republic of China
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17
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Chen W, Green KD, Tsodikov OV, Garneau-Tsodikova S. Aminoglycoside multiacetylating activity of the enhanced intracellular survival protein from Mycobacterium smegmatis and its inhibition. Biochemistry 2012; 51:4959-67. [PMID: 22646013 DOI: 10.1021/bi3004473] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The enhanced intracellular survival (Eis) protein improves the survival of Mycobacterium smegmatis (Msm) in macrophages and functions as the acetyltransferase responsible for kanamycin A resistance, a hallmark of extensively drug-resistant (XDR) tuberculosis, in a large number of Mycobacterium tuberculosis (Mtb) clinical isolates. We recently demonstrated that Eis from Mtb (Eis_Mtb) efficiently multiacetylates a variety of aminoglycoside (AG) antibiotics. Here, to gain insight into the origin of substrate selectivity of AG multiacetylation by Eis, we analyzed AG acetylation by Eis_Msm, investigated its inhibition, and compared these functions to those of Eis_Mtb. Even though for several AGs the multiacetylation properties of Eis_Msm and Eis_Mtb are similar, there are three major differences. (i) Eis_Msm diacetylates apramycin, a conformationally constrained AG, which Eis_Mtb cannot modify. (ii) Eis_Msm triacetylates paromomycin, which can be only diacetylated by Eis_Mtb. (iii) Eis_Msm only monoacetylates hygromycin, a structurally unique AG that is diacetylated by Eis_Mtb. Several nonconserved amino acid residues lining the AG-binding pocket of Eis are likely responsible for these differences between the two Eis homologues. Specifically, we propose that because the AG-binding pocket of Eis_Msm is more open than that of Eis_Mtb, it accommodates apramycin for acetylation in Eis_Msm, but not in Eis_Mtb. We also demonstrate that inhibitors of Eis_Mtb that we recently discovered can inhibit Eis_Msm activity. These observations help define the structural origins of substrate preference among Eis homologues and suggest that Eis_Mtb inhibitors may be applied against all pathogenic mycobacteria to overcome AG resistance caused by Eis upregulation.
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Affiliation(s)
- Wenjing Chen
- Life Sciences Institute, 210 Washtenaw Avenue, University of Michigan, Ann Arbor, Michigan 48109-2216, USA
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18
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Direct drug susceptibility testing of Mycobacterium tuberculosis for rapid detection of multidrug resistance using the Bactec MGIT 960 system: a multicenter study. J Clin Microbiol 2011; 50:435-40. [PMID: 22162558 DOI: 10.1128/jcm.05188-11] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conventional indirect drug susceptibility testing of Mycobacterium tuberculosis with liquid medium is well established and offers time-saving and reliable results. This multicenter study was carried out to evaluate if drug susceptibility testing (DST) can be successfully carried out directly from processed smear-positive specimens (direct DST) and if this approach could offer substantial time savings. Sputum specimens were digested, decontaminated, and concentrated by the laboratory routine procedure and were inoculated in Bactec MGIT 960 as well as Lowenstein-Jensen (LJ) medium for primary isolation. All the processed specimens which were acid-fast bacterium (AFB) smear positive were used for setting up direct DST for isoniazid (INH) and rifampin (RIF). After the antimicrobial mixture of polymyxin B, amphotericin B, nalidixic acid, trimethoprim, and azlocillin (PANTA) was added, the tubes were entered in the MGIT 960 instrument using the 21-day protocol (Bactec 960 pyrazinamide [PZA] protocol). Results obtained by direct DST were compared with those obtained by indirect DST to establish accuracy and time savings by this approach. Of a total of 360 AFB smear-positive sputum specimens set up for direct DST at four sites in three different countries, 307 (85%) specimens yielded reportable results. Average reporting time for direct DST was 11 days (range, 10 to 12 days). The average time savings by direct DST compared to indirect DST, which included time to isolate a culture and perform DST, was 8 days (range, 6 to 9 days). When results of direct DST were compared with those of indirect DST, there was 95.1% concordance with INH and 96.1% with rifampin. These findings indicate that direct DST with the Bactec MGIT 960 system offers further time savings and is a quick method to reliably detect multidrug resistance (MDR) cases.
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Abuali MM, Katariwala R, LaBombardi VJ. A comparison of the Sensititre® MYCOTB panel and the agar proportion method for the susceptibility testing of Mycobacterium tuberculosis. Eur J Clin Microbiol Infect Dis 2011; 31:835-9. [PMID: 21866324 DOI: 10.1007/s10096-011-1382-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 08/03/2011] [Indexed: 11/25/2022]
Abstract
The agar proportion method (APM) for determining Mycobacterium tuberculosis susceptibilities is a qualitative method that requires 21 days in order to produce the results. The Sensititre method allows for a quantitative assessment. Our objective was to compare the accuracy, time to results, and ease of use of the Sensititre method to the APM. 7H10 plates in the APM and 96-well microtiter dry MYCOTB panels containing 12 antibiotics at full dilution ranges in the Sensititre method were inoculated with M. tuberculosis and read for colony growth. Thirty-seven clinical isolates were tested using both methods and 26 challenge strains of blinded susceptibilities were tested using the Sensititre method only. The Sensititre method displayed 99.3% concordance with the APM. The APM provided reliable results on day 21, whereas the Sensititre method displayed consistent results by day 10. The Sensititre method provides a more rapid, quantitative, and efficient method of testing both first- and second-line drugs when compared to the gold standard. It will give clinicians a sense of the degree of susceptibility, thus, guiding the therapeutic decision-making process. Furthermore, the microwell plate format without the need for instrumentation will allow its use in resource-poor settings.
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Affiliation(s)
- M M Abuali
- Department of Pediatric Infectious Diseases, Mount Sinai School of Medicine, Mount Sinai Medical Center, 1 Gustave L. Levy Place, Box 1657, New York, NY 10029, USA.
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Pandit P, Tiwari S. Recent advances in the chemotherapy of tuberculosis. INDIAN JOURNAL OF RHEUMATOLOGY 2011. [DOI: 10.1016/s0973-3698(11)60039-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Zhang H, Peng P, Miao S, Zhao Y, Mao F, Wang L, Bai Y, Xu Z, Wei S, Shi C. Recombinant Mycobacterium smegmatis expressing an ESAT6-CFP10 fusion protein induces anti-mycobacterial immune responses and protects against Mycobacterium tuberculosis challenge in mice. Scand J Immunol 2010; 72:349-57. [PMID: 20883320 DOI: 10.1111/j.1365-3083.2010.02448.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The currently used vaccine against tuberculosis, Bacille Calmette-Guérin (BCG), has variable efficacy, so new vaccine development is crucial. In this study, we evaluated a recombinant vaccine prepared from non-pathogenic Mycobacterium smegmatis (rMS) that expresses a fusion of early secreted antigenic target 6-kDa antigen (ESAT6) and culture filtrate protein 10 (CFP10). C57BL/6 mice were immunized with the rMS expressing the ESAT6-CFP10 fusion protein (rM.S-e6c10) or with BCG. The mice in the rM.S-e6c10 group had a significantly higher titre of anti-ESAT6-CFP10 antibodies than did animals in the BCG or saline groups. Spleen cells from rM.S-e6c10-immunized mice exhibited a cytotoxic response to ESAT6 and CFP10-expressed target cells, but spleen cells from animals in the other groups did not. Levels of IFN-γ and IL-2 production by purified T cells from spleens were significantly higher in rM.S-e6c10 group than in BCG group. Finally, after M. tuberculosis (MTB)-challenged mice, dramatic reduction in the numbers of MTB colony-forming units (CFUs) in the lungs was observed for the mice immunized with the rMS. The protective efficacy of rM.S-e6c10 and BCG vaccination was similar based on measures of MTB burden and lung pathology. Our data indicate that the recombinant M. smegmatis vaccine expressing the ESAT6-CFP10 fusion protein has potential in clinic application.
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Affiliation(s)
- H Zhang
- Laboratory Animal Center, Fourth Military Medical University, Xi'an, China
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Vinson HM, Gautam A, Olet S, Gibbs PS, Barigye R. Molecular analysis of porin gene transcription in heterogenotypic multidrug-resistant Escherichia coli isolates from scouring calves. J Antimicrob Chemother 2010; 65:1926-35. [PMID: 20639525 DOI: 10.1093/jac/dkq246] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Despite evidence that altered membrane porins may impair microbial drug uptake thereby potentially compounding efflux pump-mediated multidrug resistance, few studies have evaluated gene transcription to identify multidrug-resistance-associated porins and other potential drug targets. METHODS Genes that encode six membrane porins (fadL, lamB, ompC, ompF, ompW and yiaT) and two membrane proteins (tolC and ompT) were assessed by PCR and by quantitative real-time PCR (qRT-PCR) analysis of 10 multidrug-resistant (MDR) and 10 antibiotic-susceptible (AS) Escherichia coli isolates. The mean DeltaDeltaCt values for the study E. coli genes were analysed by the Wilcoxon test (P = 0.05). RESULTS All 20 E. coli isolates tested positive for tolC, lamB, ompC, ompF genes, while 10 MDR and 9/10 (90%) AS isolates were positive for the fadL gene. Seven out of 10 (70%) MDR and 7/10 (70%) AS isolates were positive for the yiaT gene, while 7/10 (70%) MDR and only 4/10 (40%) AS isolates were positive for the ompT gene. The mean DeltaDeltaCt values for the tolC and yiaT genes were significantly higher in MDR than in AS isolates (Wilcoxon test; P < 0.05). No significant difference was seen with respect to fadL, lamB, ompC, ompF, ompT and ompW gene transcription (Wilcoxon test; P > 0.05). CONCLUSIONS Findings suggest up-regulated transcription of tolC and yiaT genes in the MDR E. coli isolates. These results indirectly suggest that TolC and YiaT proteins may play some role(s) in multidrug resistance, but proteomic studies are needed before the two proteins are considered potential drug targets.
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Affiliation(s)
- Heather M Vinson
- Department of Veterinary and Microbiological Sciences, North Dakota State University, 1523 Centennial Blvd, Fargo, ND 58108, USA
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Abstract
In this issue of Molecular Cell, Kohanski et al. (2010) demonstrate that even subinhibitory concentrations of bactericidal antibiotics result in the generation of reactive oxygen species, leading to an increase in mutation rate and the emergence of multidrug-resistant bacterial strains.
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Affiliation(s)
- Benjamin B Kaufmann
- Infectious Disease Initiative, The Broad Institute, Cambridge, MA 02141, USA; Massachusetts General Hospital, Boston, MA 02114, USA
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Multicenter evaluation of Bactec MGIT 960 system for second-line drug susceptibility testing of Mycobacterium tuberculosis complex. J Clin Microbiol 2009; 47:3630-4. [PMID: 19741086 DOI: 10.1128/jcm.00803-09] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bactec MGIT 960 system for testing susceptibility to second-line drugs was evaluated with 117 clinical strains in a multicenter study. The four drugs studied were levofloxacin, amikacin, capreomycin, and ethionamide. The critical concentration established for levofloxacin and amikacin was 1.5 microg/ml, that established for capreomycin was 3.0 microg/ml, and that established for ethionamide was 5.0 microg/ml. The overall level of agreement between the agar proportion method and the MGIT 960 system was 96.4%, and the levels of agreement for the individuals drugs were 99.1% for levofloxacin, 100% for amikacin, 97.4% for capreomycin, and 88.9% for ethionamide. The rate of reproducibility of the drug susceptibility testing results between the participating laboratories was 99.5%.
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Haebich D, von Nussbaum F. Lost in transcription--inhibition of RNA polymerase. Angew Chem Int Ed Engl 2009; 48:3397-400. [PMID: 19294713 DOI: 10.1002/anie.200900338] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Form and function: The natural product myxopyronin A provides the key to understanding the inhibition of bacterial RNA polymerase and should spark new ideas for the design of new antibiotics against tuberculosis and other infectious diseases.
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Affiliation(s)
- Dieter Haebich
- Bayer Schering Pharma AG, Medicinal Chemistry Europe, 42096 Wuppertal, Germany.
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Rosen Y, Elman NM. Carbon nanotubes in drug delivery: focus on infectious diseases. Expert Opin Drug Deliv 2009; 6:517-30. [DOI: 10.1517/17425240902865579] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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