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Kumar A, Kamuju V, Vivekanandan P. RNA G-quadruplexes inhibit translation of the PE/PPE transcripts in Mycobacterium tuberculosis. J Biol Chem 2024; 300:105567. [PMID: 38103641 PMCID: PMC10801317 DOI: 10.1016/j.jbc.2023.105567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/22/2023] [Accepted: 12/08/2023] [Indexed: 12/19/2023] Open
Abstract
The role of RNA G-quadruplexes (rG4s) in bacteria remains poorly understood. High G-quadruplex densities have been linked to organismal stress. Here we investigate rG4s in mycobacteria, which survive highly stressful conditions within the host. We show that rG4-enrichment is a unique feature exclusive to slow-growing pathogenic mycobacteria, and Mycobacterium tuberculosis (Mtb) transcripts contain an abundance of folded rG4s. Notably, the PE/PPE family of genes, unique to slow-growing pathogenic mycobacteria, contain over 50% of rG4s within Mtb transcripts. We found that RNA oligonucleotides of putative rG4s in PE/PPE genes form G-quadruplex structures in vitro, which are stabilized by the G-quadruplex ligand BRACO19. Furthermore, BRACO19 inhibits the transcription of PE/PPE genes and selectively suppresses the growth of Mtb but not Mycobacterium smegmatis or other rapidly growing bacteria. Importantly, the stabilization of rG4s inhibits the translation of Mtb PE/PPE genes (PPE56, PPE67, PPE68, PE_PGRS39, and PE_PGRS41) ectopically expressed in M. smegmatis or Escherichia coli. In addition, the rG4-mediated reduction in PE/PPE protein levels attenuates proinflammatory response upon infection of THP-1 cells. Our findings shed new light on the regulation of PE/PPE genes and highlight a pivotal role for rG4s in Mtb transcripts as regulators of post-transcriptional translational control. The rG4s in mycobacterial transcripts may represent potential drug targets for newer therapies.
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Affiliation(s)
- Ashish Kumar
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Vinay Kamuju
- Department of Biochemical Engineering & Biotechnology, Indian Institute of Technology, New Delhi, India
| | - Perumal Vivekanandan
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India.
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Shaku MT, Ocius KL, Apostolos AJ, Pires MM, VanNieuwenhze MS, Dhar N, Kana BD. Amidation of glutamate residues in mycobacterial peptidoglycan is essential for cell wall cross-linking. Front Cell Infect Microbiol 2023; 13:1205829. [PMID: 37692163 PMCID: PMC10484409 DOI: 10.3389/fcimb.2023.1205829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction Mycobacteria assemble a complex cell wall with cross-linked peptidoglycan (PG) which plays an essential role in maintenance of cell wall integrity and tolerance to osmotic pressure. We previously demonstrated that various hydrolytic enzymes are required to remodel PG during essential processes such as cell elongation and septal hydrolysis. Here, we explore the chemistry associated with PG cross-linking, specifically the requirement for amidation of the D-glutamate residue found in PG precursors. Methods Synthetic fluorescent probes were used to assess PG remodelling dynamics in live bacteria. Fluorescence microscopy was used to assess protein localization in live bacteria and CRISPR-interference was used to construct targeted gene knockdown strains. Time-lapse microscopy was used to assess bacterial growth. Western blotting was used to assess protein phosphorylation. Results and discussion In Mycobacterium smegmatis, we confirmed the essentiality for D-glutamate amidation in PG biosynthesis by labelling cells with synthetic fluorescent PG probes carrying amidation modifications. We also used CRISPRi targeted knockdown of genes encoding the MurT-GatD complex, previously implicated in D-glutamate amidation, and demonstrated that these genes are essential for mycobacterial growth. We show that MurT-rseGFP co-localizes with mRFP-GatD at the cell poles and septum, which are the sites of cell wall synthesis in mycobacteria. Furthermore, time-lapse microscopic analysis of MurT-rseGFP localization, in fluorescent D-amino acid (FDAA)-labelled mycobacterial cells during growth, demonstrated co-localization with maturing PG, suggestive of a role for PG amidation during PG remodelling and repair. Depletion of MurT and GatD caused reduced PG cross-linking and increased sensitivity to lysozyme and β-lactam antibiotics. Cell growth inhibition was found to be the result of a shutdown of PG biosynthesis mediated by the serine/threonine protein kinase B (PknB) which senses uncross-linked PG. Collectively, these data demonstrate the essentiality of D-glutamate amidation in mycobacterial PG precursors and highlight the MurT-GatD complex as a novel drug target.
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Affiliation(s)
- Moagi T. Shaku
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis (TB) Research, Faculty of Health Sciences, University of the Witwatersrand, National Health Laboratory Service, Johannesburg, South Africa
| | - Karl L. Ocius
- Department of Chemistry, University of Virginia, Charlottesville, VA, United States
| | - Alexis J. Apostolos
- Department of Chemistry, University of Virginia, Charlottesville, VA, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, VA, United States
| | | | - Neeraj Dhar
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Bavesh D. Kana
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis (TB) Research, Faculty of Health Sciences, University of the Witwatersrand, National Health Laboratory Service, Johannesburg, South Africa
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Grigorov A, Bychenko O, Salina EG, Skvortsova Y, Mazurova A, Skvortsov T, Kaprelyants A, Azhikina T. Small RNA F6 Provides Mycobacterium smegmatis Entry into Dormancy. Int J Mol Sci 2021; 22:11536. [PMID: 34768965 PMCID: PMC8583896 DOI: 10.3390/ijms222111536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 11/16/2022] Open
Abstract
Regulatory small non-coding RNAs play a significant role in bacterial adaptation to changing environmental conditions. Various stresses such as hypoxia and nutrient starvation cause a reduction in the metabolic activity of Mycobacterium smegmatis, leading to entry into dormancy. We investigated the functional role of F6, a small RNA of M. smegmatis, and constructed an F6 deletion strain of M. smegmatis. Using the RNA-seq approach, we demonstrated that gene expression changes that accompany F6 deletion contributed to bacterial resistance against oxidative stress. We also found that F6 directly interacted with 5'-UTR of MSMEG_4640 mRNA encoding RpfE2, a resuscitation-promoting factor, which led to the downregulation of RpfE2 expression. The F6 deletion strain was characterized by the reduced ability to enter into dormancy (non-culturability) in the potassium deficiency model compared to the wild-type strain, indicating that F6 significantly contributes to bacterial adaptation to non-optimal growth conditions.
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Affiliation(s)
- Artem Grigorov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.G.); (O.B.); (Y.S.); (A.M.)
| | - Oksana Bychenko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.G.); (O.B.); (Y.S.); (A.M.)
| | - Elena G. Salina
- Research Center of Biotechnology, Bach Institute of Biochemistry, 119071 Moscow, Russia; (E.G.S.); (A.K.)
| | - Yulia Skvortsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.G.); (O.B.); (Y.S.); (A.M.)
| | - Arina Mazurova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.G.); (O.B.); (Y.S.); (A.M.)
| | - Timofey Skvortsov
- School of Pharmacy, Queen’s University Belfast, Belfast BT9 7BL, UK;
| | - Arseny Kaprelyants
- Research Center of Biotechnology, Bach Institute of Biochemistry, 119071 Moscow, Russia; (E.G.S.); (A.K.)
| | - Tatyana Azhikina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.G.); (O.B.); (Y.S.); (A.M.)
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4
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Ghosh P, Barman A, Das Gupta SK. Induced expression of the zwf gene in the presence of glucose contributes to lowering of glucose 6-phosphate level and consequently reduction of growth rate of Mycobacterium smegmatis. Microbiology (Reading) 2021; 167. [PMID: 34236958 DOI: 10.1099/mic.0.001067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In Mycobacterium smegmatis (renamed Mycolicibacterium smegmatis), glucose 6-phosphate (G6P) level is exceptionally high as compared to other bacteria, E. coli for example. Earlier investigations have indicated that G6P protects M. smegmatis (Msm) against oxidative stress-inducing agents. G6P is a glycolytic intermediate formed either directly through the phosphorylation of glucose or indirectly via the gluconeogenic pathway. Its consumption is catalysed by several enzymes, one of which being the NADPH dependent G6P dehydrogenase (G6PDH) encoded by zwf (msmeg_0314). While investigating the extent to which the carbon sources glucose and glycerol influence Msm growth, we observed that intracellular concentration of G6P was lower in the former's presence than the latter. We could correlate this difference with that in the growth rate, which was higher in glycerol than glucose. We also found that lowering of G6P content in glucose-grown cells was triggered by the induced expression of zwf and the resultant increase in G6PDH activity. When we silenced zwf using CRISPR-Cas9 technology, we observed a significant rise in the growth rate of Msm. Therefore, we have found that depletion of G6P in glucose-grown cells due to increased G6PDH activity is at least one reason why the growth rate of Msm in glucose is less than glycerol. However, we could not establish a similar link-up between slow growth in glucose and lowering of G6P level in the case of Mycobacterium tuberculosis (Mtb). Mycobacteria, therefore, may have evolved diverse mechanisms to ensure that they use glycerol preferentially over glucose for their growth.
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Affiliation(s)
- Poulami Ghosh
- Department of Microbiology, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata-700054, India
| | - Anik Barman
- Department of Microbiology, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata-700054, India
| | - Sujoy K Das Gupta
- Department of Microbiology, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata-700054, India
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Quaresma S, Alves PC, Rijo P, Duarte MT, André V. Antimicrobial Activity of Pyrazinamide Coordination Frameworks Synthesized by Mechanochemistry. Molecules 2021; 26:1904. [PMID: 33800635 PMCID: PMC8036749 DOI: 10.3390/molecules26071904] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/21/2021] [Accepted: 03/25/2021] [Indexed: 11/16/2022] Open
Abstract
The urge for the development of a more efficient antibiotic crystalline forms led us to the disclosure of new antibiotic coordination frameworks of pyrazinamide, a well-known drug used for the treatment of tuberculosis, with some of the novel compounds unravelling improved antimycobacterial activity. Mechanochemistry was the preferred synthetic technique to yield novel compounds, allowing the reproduction of a 1D zinc framework, the synthesis of a novel hydrogen bonding manganese framework, and three new compounds with silver. The structural characterization of the novel forms is presented along with stability studies. The increased antimicrobial activity of the new silver-based frameworks against Escherichia coli, Staphylococcus aureus, and Mycobacterium smegmatis is particularly relevant.
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Affiliation(s)
- Sílvia Quaresma
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (S.Q.); (P.C.A.)
| | - Paula C. Alves
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (S.Q.); (P.C.A.)
- Associação do Instituto Superior Técnico para a Investigação e Desenvolvimento (IST-ID), Av. Rovisco Pais, 1049-003 Lisboa, Portugal
| | - Patrícia Rijo
- Centro de Investigação em Biociências e Tecnologias da Saúde (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, Campo Grande 376, 1749-024 Lisboa, Portugal;
- Research Institute for Medicines (iMed. ULisboa), Faculty of Pharmacy, Universidade de Lisboa (UL), Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - M. Teresa Duarte
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (S.Q.); (P.C.A.)
- Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Vânia André
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (S.Q.); (P.C.A.)
- Associação do Instituto Superior Técnico para a Investigação e Desenvolvimento (IST-ID), Av. Rovisco Pais, 1049-003 Lisboa, Portugal
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6
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Judd JA, Canestrari J, Clark R, Joseph A, Lapierre P, Lasek-Nesselquist E, Mir M, Palumbo M, Smith C, Stone M, Upadhyay A, Wirth SE, Dedrick RM, Meier CG, Russell DA, Dills A, Dove E, Kester J, Wolf ID, Zhu J, Rubin ER, Fortune S, Hatfull GF, Gray TA, Wade JT, Derbyshire KM. A Mycobacterial Systems Resource for the Research Community. mBio 2021; 12:e02401-20. [PMID: 33653882 PMCID: PMC8092266 DOI: 10.1128/mbio.02401-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Functional characterization of bacterial proteins lags far behind the identification of new protein families. This is especially true for bacterial species that are more difficult to grow and genetically manipulate than model systems such as Escherichia coli and Bacillus subtilis To facilitate functional characterization of mycobacterial proteins, we have established a Mycobacterial Systems Resource (MSR) using the model organism Mycobacterium smegmatis This resource focuses specifically on 1,153 highly conserved core genes that are common to many mycobacterial species, including Mycobacterium tuberculosis, in order to provide the most relevant information and resources for the mycobacterial research community. The MSR includes both biological and bioinformatic resources. The biological resource includes (i) an expression plasmid library of 1,116 genes fused to a fluorescent protein for determining protein localization; (ii) a library of 569 precise deletions of nonessential genes; and (iii) a set of 843 CRISPR-interference (CRISPRi) plasmids specifically targeted to silence expression of essential core genes and genes for which a precise deletion was not obtained. The bioinformatic resource includes information about individual genes and a detailed assessment of protein localization. We anticipate that integration of these initial functional analyses and the availability of the biological resource will facilitate studies of these core proteins in many Mycobacterium species, including the less experimentally tractable pathogens M. abscessus, M. avium, M. kansasii, M. leprae, M. marinum, M. tuberculosis, and M. ulceransIMPORTANCE Diseases caused by mycobacterial species result in millions of deaths per year globally, and present a substantial health and economic burden, especially in immunocompromised patients. Difficulties inherent in working with mycobacterial pathogens have hampered the development and application of high-throughput genetics that can inform genome annotations and subsequent functional assays. To facilitate mycobacterial research, we have created a biological and bioinformatic resource (https://msrdb.org/) using Mycobacterium smegmatis as a model organism. The resource focuses specifically on 1,153 proteins that are highly conserved across the mycobacterial genus and, therefore, likely perform conserved mycobacterial core functions. Thus, functional insights from the MSR will apply to all mycobacterial species. We believe that the availability of this mycobacterial systems resource will accelerate research throughout the mycobacterial research community.
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Affiliation(s)
- J A Judd
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - J Canestrari
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - R Clark
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - A Joseph
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - P Lapierre
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - E Lasek-Nesselquist
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - M Mir
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - M Palumbo
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - C Smith
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - M Stone
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - A Upadhyay
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - S E Wirth
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - R M Dedrick
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - C G Meier
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - D A Russell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - A Dills
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - E Dove
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - J Kester
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - I D Wolf
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - J Zhu
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - E R Rubin
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - S Fortune
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - G F Hatfull
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - T A Gray
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - J T Wade
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - K M Derbyshire
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
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Li Y, Keshavan P, Corro JH, Koripella RK, Agrawal RK, Ojha AK. Purification of Hibernating and Active C- Ribosomes from Zinc-Starved Mycobacteria. Methods Mol Biol 2021; 2314:151-166. [PMID: 34235651 DOI: 10.1007/978-1-0716-1460-0_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Zinc starvation in Mycobacterium smegmatis and Mycobacterium tuberculosis induces ribosome remodeling and hibernation. Remodeling involves replacement of C+ ribosomal (r-) proteins containing the zinc-binding CXXC motif with their C- paralogues without the motif. Hibernation is characterized by binding of mycobacterial-specific protein Y (Mpy) to 70S C- ribosomes, stabilizing the ribosome in an inactive state that is also resistant to kanamycin and streptomycin. We observed that ribosome remodeling and hibernation occur at two different concentrations of cellular zinc. Here, we describe the methods to purify hibernating and active forms of C- ribosomes from zinc-starved mycobacteria, along with purification of C+ ribosomes from zinc-rich mycobacterial cells. In vitro analysis of these distinct types of ribosomes will facilitate screening of small molecule inhibitors of ribosome hibernation for improved therapeutics against mycobacterial infections.
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Affiliation(s)
- Yunlong Li
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Pooja Keshavan
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Jamie H Corro
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA
- Department of Biomedical Sciences, University at Albany, Albany, NY, USA
| | - Ravi K Koripella
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Rajendra K Agrawal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Albany, NY, USA
- Department of Biomedical Sciences, University at Albany, Albany, NY, USA
| | - Anil K Ojha
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA.
- Department of Biomedical Sciences, University at Albany, Albany, NY, USA.
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Andrews ESV, Rzoska-Smith E, Arcus VL. Post-transcriptional modulation of the SigF regulon in Mycobacterium smegmatis by the PhoH2 toxin-antitoxin. PLoS One 2020; 15:e0236551. [PMID: 32726339 PMCID: PMC7390352 DOI: 10.1371/journal.pone.0236551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 07/06/2020] [Indexed: 01/03/2023] Open
Abstract
PhoH2 proteins are highly conserved across bacteria and archaea yet their biological function is poorly characterised. We examined the growth profiles of Mycobacterium smegmatis strains mc2155 and mc2155 ΔphoH2 and observed the same growth profile and growth rate in a variety of conditions. In light of the comparable growth, we used RNAseq to provide a snapshot of the differences between the transcriptomes of M. smegmatis mc2155 and M. smegmatis mc2155 ΔphoH2 during normal growth. At 48 hours, elevated expression of the sigF regulon was observed in ΔphoH2 relative to wild type. In biochemical assays, PhoH2 showed activity toward sigF mRNA insinuating a role of PhoH2 in modulating the pool of sigF mRNA in the cell during normal growth, adding further complexity to the repertoire of reported mechanisms of post-translational regulation. Multiple copies of the preferred target site of PhoH2 were identified in loops of the sigF mRNA structure, leading us to propose a mechanism for the activity of PhoH2 that is initiated after assembly on specific single-stranded loops of RNA. We hypothesise that PhoH2 is a toxin-antitoxin that contributes to the regulation of SigF at a post-transcriptional level through targeted activity on sigF mRNA. This work presents the first evidence for post-transcriptional regulation of SigF along with the biological function of PhoH2 from M. smegmatis. This has implications for the highly conserved PhoH2 toxin-antitoxin module across the mycobacteria including the important human pathogen M. tuberculosis.
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Affiliation(s)
- Emma S. V. Andrews
- School of Science, Division of Health, Engineering, Computing and Science, University of Waikato, Hamilton, New Zealand
- * E-mail:
| | - Elizabeth Rzoska-Smith
- School of Science, Division of Health, Engineering, Computing and Science, University of Waikato, Hamilton, New Zealand
| | - Vickery L. Arcus
- School of Science, Division of Health, Engineering, Computing and Science, University of Waikato, Hamilton, New Zealand
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Arriaga-Guerrero AL, Hernández-Luna CE, Rigal-Leal J, Robles-González RJ, González-Escalante LA, Silva-Ramírez B, Mercado-Hernández R, Vargas-Villarreal J, Bermúdez de León M, Peñuelas-Urquides K. LipF increases rifampicin and streptomycin sensitivity in a Mycobacterium tuberculosis surrogate. BMC Microbiol 2020; 20:132. [PMID: 32450809 PMCID: PMC7249682 DOI: 10.1186/s12866-020-01802-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 04/23/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Mortality due to tuberculosis (TB) has increased due to the development of drug resistance, the mechanisms of which have not been fully elucidated. Our research group identified a low expression of lipF gene in Mycobacterium tuberculosis clinical isolates with drug resistance. The aim of this work was to evaluate the effect of lipase F (LipF) expression on mycobacterial drug resistance. RESULTS The effects of expressing lipF from Mycobacterium tuberculosis in Mycobacterium smegmatis on resistance to antituberculosis drugs were determined with resazurin microtiter assay plate and growth kinetics. Functionality of ectopic LipF was confirmed. LipF expression reduced the rifampicin (RIF) and streptomycin (STR) minimum inhibitory concentration (MIC) from 3.12 μg/mL to 1.6 μg/mL and 0.25 μg/mL to 0.06 μg/mL respectively, moreover a reduced M. smegmatis growth in presence of RIF and STR compared with that of a control strain without LipF expression (p < 0.05 and p < 0.01) was shown. CONCLUSIONS LipF expression was associated with increased RIF and STR sensitivity in mycobacteria. Reduced LipF expression may contribute to the development of RIF and STR resistance in Mycobacterium species. Our findings provide information pertinent to understanding mycobacterial drug resistance mechanisms.
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Affiliation(s)
- Ana Leticia Arriaga-Guerrero
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, México
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Carlos E Hernández-Luna
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Joyce Rigal-Leal
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Rene J Robles-González
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Laura Adiene González-Escalante
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, México
| | - Beatriz Silva-Ramírez
- Departamento de Inmunogenética, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, México
| | - Roberto Mercado-Hernández
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Javier Vargas-Villarreal
- Departamento de Biología Celular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, México
| | - Mario Bermúdez de León
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, México
| | - Katia Peñuelas-Urquides
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, México.
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10
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Tan YZ, Zhang L, Rodrigues J, Zheng RB, Giacometti SI, Rosário AL, Kloss B, Dandey VP, Wei H, Brunton R, Raczkowski AM, Athayde D, Catalão MJ, Pimentel M, Clarke OB, Lowary TL, Archer M, Niederweis M, Potter CS, Carragher B, Mancia F. Cryo-EM Structures and Regulation of Arabinofuranosyltransferase AftD from Mycobacteria. Mol Cell 2020; 78:683-699.e11. [PMID: 32386575 PMCID: PMC7263364 DOI: 10.1016/j.molcel.2020.04.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/21/2020] [Accepted: 04/13/2020] [Indexed: 01/21/2023]
Abstract
Mycobacterium tuberculosis causes tuberculosis, a disease that kills over 1 million people each year. Its cell envelope is a common antibiotic target and has a unique structure due, in part, to two lipidated polysaccharides-arabinogalactan and lipoarabinomannan. Arabinofuranosyltransferase D (AftD) is an essential enzyme involved in assembling these glycolipids. We present the 2.9-Å resolution structure of M. abscessus AftD, determined by single-particle cryo-electron microscopy. AftD has a conserved GT-C glycosyltransferase fold and three carbohydrate-binding modules. Glycan array analysis shows that AftD binds complex arabinose glycans. Additionally, AftD is non-covalently complexed with an acyl carrier protein (ACP). 3.4- and 3.5-Å structures of a mutant with impaired ACP binding reveal a conformational change, suggesting that ACP may regulate AftD function. Mutagenesis experiments using a conditional knockout constructed in M. smegmatis confirm the essentiality of the putative active site and the ACP binding for AftD function.
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Affiliation(s)
- Yong Zi Tan
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - José Rodrigues
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), 2780-157 Oeiras, Portugal
| | | | - Sabrina I Giacometti
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Ana L Rosário
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), 2780-157 Oeiras, Portugal
| | - Brian Kloss
- Center on Membrane Protein Production and Analysis, New York Structural Biology Center, New York, NY 10027, USA
| | - Venkata P Dandey
- National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Hui Wei
- National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Richard Brunton
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Ashleigh M Raczkowski
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Diogo Athayde
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), 2780-157 Oeiras, Portugal
| | - Maria João Catalão
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal
| | - Madalena Pimentel
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal
| | - Oliver B Clarke
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; Department of Anesthesiology, Columbia University, New York, NY 10032, USA
| | - Todd L Lowary
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; Institute of Biological Chemistry, Academia Sinica, Academia Road, Section 2, #128 Nangang, Taipei 11529, Taiwan
| | - Margarida Archer
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), 2780-157 Oeiras, Portugal
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Clinton S Potter
- National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA; Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Bridget Carragher
- National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA; Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA.
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11
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Kapoor I, Varada R, Aroli S, Varshney U. Nudix hydrolases with Coenzyme A (CoA) and acyl-CoA pyrophosphatase activities confer growth advantage to Mycobacterium smegmatis. Microbiology (Reading) 2019; 165:1219-1232. [PMID: 31526453 DOI: 10.1099/mic.0.000850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nudix hydrolase family proteins hydrolyse toxic by-products of cellular metabolism such as mutagenic nucleoside triphosphates, sugar nucleotides and signalling molecules. We studied the substrate specificities of Nudix hydrolases encoded by rv3672c and rv3040c from Mycobacterium tuberculosis and their respective homologues, msmeg_6185 and msmeg_2327 from M. smegmatis. The rv3672c- and msmeg_6185-encoded proteins (Rv3672 and MSMEG_6185, respectively) showed CoA pyrophosphatase (CoAse) activity that converted acyl-CoA to adenosine-3',5'-diphosphate (3', 5'-ADP) and 4-acyl phosphopantetheine. The efficiencies of Rv3672 and MSMEG_6185 in hydrolysing CoA derivatives were found to be higher than those of the Rv3040 and MSMEG_2327 (encoded by rv3040c and msmeg_2327, respectively). Further, amongst the substrates tested, Rv3672 and MSMEG_6185 used CoA and oxidized CoA as the most preferred substrates. Use of the M. smegmatis model showed that the expression of msmeg_6185 occurs in the log and stationary phases but declines during the late stationary phase and becomes undetectable during hypoxia. The co-culture competition experiments performed between the wild-type and Δmsmeg_6185 strains of M. smegmatis in different carbon sources revealed that the presence of msmeg_6185 provided growth fitness advantage to M. smegmatis, irrespective of the carbon source, implicating its function in regulation for the optimal physiological levels of acyl-CoAs in the cell.
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Affiliation(s)
- Indu Kapoor
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Rajagopal Varada
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Shashanka Aroli
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Umesh Varshney
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
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12
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Dubey AA, Jain V. Mycofactocin is essential for the establishment of methylotrophy in Mycobacterium smegmatis. Biochem Biophys Res Commun 2019; 516:1073-1077. [PMID: 31279528 DOI: 10.1016/j.bbrc.2019.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 07/01/2019] [Indexed: 12/21/2022]
Abstract
Mycobacterium smegmatis possesses (N,N-dimethyl-4-nitrosoaniline)-dependent (NDMA) methanol dehydrogenase (Mno) to establish methylotrophy by utilizing methanol as the source of both carbon and energy. In this study, we show that Mno forms decamer and has NADPH as the bound cofactor. Interestingly, Mno uses NDMA and not NADP+ as an electron acceptor in in vitro reactions. We further show that the operon mftAD required for the biosynthesis of mycofactocin, a ribosomally-synthesized electron carrier, is indispensable for the growth of M. smegmatis on methanol. Our data obtained from 2,6-Dichlorophenolindophenol reduction assays also suggest that Mno uses mycofactocin as an in vivo electron acceptor for the oxidation of methanol to formaldehyde. We thus provide here biochemical evidence for mycofactocin as an electron carrier in mycobacterial physiology.
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Affiliation(s)
- Abhishek Anil Dubey
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India
| | - Vikas Jain
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India.
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13
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Singh S, Godavarthi S, Kumar A, Sen R. A mycobacteriophage genomics approach to identify novel mycobacteriophage proteins with mycobactericidal properties. Microbiology (Reading) 2019; 165:722-736. [PMID: 31091188 DOI: 10.1099/mic.0.000810] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mycobacteriophages that are specific to mycobacteria are sources of various effector proteins that are capable of eliciting bactericidal responses. We describe a genomics approach in combination with bioinformatics to identify mycobacteriophage proteins that are toxic to mycobacteria upon expression. A genomic library comprising phage genome collections was screened for clones capable of killing Mycobacterium smegmatis strain mc2155. We identified four unique clones: clones 45 and 12N (from the mycobacteriophage D29) and clones 66 and 85 (from the mycobacteriophage Che12). The gene products from clones 66 and 45 were identified as Gp49 of the Che12 phage and Gp34 of the D29 phage, respectively. The gene products of the other two clones, 85 and 12N, utilized novel open reading frames (ORFs) coding for synthetic proteins. These four clones (clones 45, 66, 85 and 12N) caused growth defects in M. smegmatis and Mycobacterium bovis upon expression. Clones with Gp49 and Gp34 also induced growth defects in Escherichia coli, indicating that they target conserved host machineries. Their expression induced various morphological changes, indicating that they affected DNA replication and cell division steps. We predicted that Gp34 is a Xis protein that is required in phage DNA excision from the bacterial chromosome. Gp49 is predicted to have an HTH motif with DNA-bending/twisting properties. We suggest that this methodology is useful to identify new phage proteins with the desired properties without laboriously characterizing the individual phages. It is universal and could be applied to other bacteria-phage systems. We speculate that the existence of a virtually unlimited number of phages with unique gene products could offer a cheaper and less hazardous alternative to explore new antimicrobial molecules.
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Affiliation(s)
- Shweta Singh
- Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Inner Ring Road, Uppal, Hyderabad-39, India
| | - Sapna Godavarthi
- Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Inner Ring Road, Uppal, Hyderabad-39, India
| | - Amit Kumar
- Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Inner Ring Road, Uppal, Hyderabad-39, India
| | - Ranjan Sen
- Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Inner Ring Road, Uppal, Hyderabad-39, India
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14
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Ealand CS, Asmal R, Mashigo L, Campbell L, Kana BD. Characterization of putative DD-carboxypeptidase-encoding genes in Mycobacterium smegmatis. Sci Rep 2019; 9:5194. [PMID: 30914728 PMCID: PMC6435803 DOI: 10.1038/s41598-019-41001-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 02/22/2019] [Indexed: 01/21/2023] Open
Abstract
Penicillin binding proteins (PBPs) are the target of numerous antimicrobial agents that disrupt bacterial cell wall synthesis. In mycobacteria, cell elongation occurs through insertion of nascent cell wall material in the sub-polar region, a process largely driven by High Molecular Weight PBPs. In contrast, the function of DD-carboxypeptidases (DD-CPases), which are Low Molecular Weight Class 1C PBPs, in mycobacteria remains poorly understood. Mycobacterium smegmatis encodes four putative DD-CPase homologues, which display homology to counterparts in Escherichia coli. Herein, we demonstrate that these are expressed in varying abundance during growth. Deletion of MSMEG_1661, MSMEG_2433 or MSMEG_2432, individually resulted in no defects in growth, cell morphology, drug susceptibility or spatial incorporation of new peptidoglycan. In contrast, deletion of MSMEG_6113 (dacB) was only possible in a merodiploid strain expressing the homologous M. tuberculosis operon encoding Rv3627c (dacB), Rv3626c, Rv3625c (mesJ) and Rv3624c (hpt), suggestive of essentiality. To investigate the role of this operon in mycobacterial growth, we depleted gene expression using anhydrotetracycline-responsive repressors and noted reduced bipolar peptidoglycan synthesis. These data point to a possible role for this four gene operon, which is highly conserved across all mycobacterial species, in regulating spatial localization of peptidoglycan synthesis.
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Affiliation(s)
- Christopher S Ealand
- DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the National Health Laboratory Service, P.O. Box 1038, Johannesburg, 2000, South Africa
| | - Rukaya Asmal
- DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the National Health Laboratory Service, P.O. Box 1038, Johannesburg, 2000, South Africa
| | - Lethabo Mashigo
- DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the National Health Laboratory Service, P.O. Box 1038, Johannesburg, 2000, South Africa
| | - Lisa Campbell
- DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the National Health Laboratory Service, P.O. Box 1038, Johannesburg, 2000, South Africa
| | - Bavesh D Kana
- DST/NRF Centre of Excellence for Biomedical TB Research, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the National Health Laboratory Service, P.O. Box 1038, Johannesburg, 2000, South Africa.
- MRC-CAPRISA HIV-TB Pathogenesis and Treatment Research Unit, Centre for the AIDS Programme of Research in South Africa, CAPRISA, Durban, South Africa.
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15
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Salih EYA, Julkunen-Tiitto R, Lampi AM, Kanninen M, Luukkanen O, Sipi M, Lehtonen M, Vuorela H, Fyhrquist P. Terminalia laxiflora and Terminalia brownii contain a broad spectrum of antimycobacterial compounds including ellagitannins, ellagic acid derivatives, triterpenes, fatty acids and fatty alcohols. J Ethnopharmacol 2018; 227:82-96. [PMID: 29733942 DOI: 10.1016/j.jep.2018.04.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 12/07/2017] [Accepted: 04/21/2018] [Indexed: 06/08/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Terminalia laxiflora Engl. & Diels, (Sudanese Arabic name: Darout الدروت) and Terminalia brownii Fresen (Sudanese Arabic name: Alshaf ألشاف) (Combretaceae) are used in Sudanese traditional folk medicine and in other African countries for treatment of infectious diseases, TB and its symptoms, such as cough, bronchitis and chest pain. AIM OF STUDY Because of the frequent use of T. laxiflora and T. brownii in African traditional medicine and due to the absence of studies regarding their antimycobacterial potential there was a need to screen extracts of T. laxiflora and T. brownii for their growth inhibitory potential and to study the chemical composition and compounds in growth inhibitory extracts. MATERIALS AND METHODS The plant species were collected in Sudan (Blue Nile Forest, Ed Damazin Forestry areas) and selected according to their uses in traditional medicine for the treatment of bacterial infections, including TB. Eighty extracts and fractions of the stem bark, stem wood, roots, leaves and fruits of T. laxiflora and T. brownii and nine pure compounds present in the active extracts were screened against Mycobacterium smegmatis ATCC 14468 using agar diffusion and microplate dilution methods. Inhibition zones and MIC values were estimated and compared to rifampicin. HPLC-UV/DAD, GC/MS and UHPLC/Q-TOF MS were employed to identify the compounds in the growth inhibitory extracts. RESULTS The roots of T. laxiflora and T. brownii gave the best antimycobacterial effects (IZ 22-27 mm) against Mycobacterium smegmatis. The lowest MIC of 625 µg/ml was observed for an acetone extract of the root of T. laxiflora followed by methanol and ethyl acetate extracts, both giving MIC values of 1250 µg/ml. Sephadex LH-20 column chromatography purification of T. brownii roots resulted in low MIC values of 62.5 µg/ml and 125 µg/ml for acetone and ethanol fractions, respectively, compared to 5000 µg/ml for the crude methanol extract. Methyl (S)-flavogallonate is suggested to be the main active compound in the Sephadex LH- 20 acetone fraction, while ellagic acid xyloside and methyl ellagic acid xyloside are suggested to give good antimycobacterial activity in the Sephadex LH-20 ethanol fraction. RP-18 TLC purifications of an ethyl acetate extract of T. laxiflora roots resulted in the enrichment of punicalagin in one of the fractions (Fr5). This fraction gave a five times smaller MIC (500 µg/ml) than the crude ethyl acetate extract (2500 µg/ml) and this improved activity is suggested to be mostly due to punicalagin. 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone and β-sitosterol were found in antimycobacterial hexane extracts of the stem bark of both studied species. Of these compounds, 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone have not been previously identified in T. brownii and T. laxiflora. Moreover, both plant species contained friedelin, betulinic acid, β-amyrine and two unknown oleanane-type triterpenoids. Of the listed compounds, friedelin, triacontanol and sitostenone gave a MIC of 250 µg/ml against M. smegmatis, whereas stigmasterol and β-sitosterol gave MIC values of 500 µg/ml. CONCLUSIONS Our results show that T. laxiflora and T. brownii contain antimycobacterial compounds of diverse polarities and support the traditional uses of various parts of T. laxiflora and T.brownii as decoctions for treatment of tuberculosis. Further investigations are warranted to explore additional (new) antimycobacterial compounds in the active extracts of T. laxiflora and T. brownii.
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Affiliation(s)
- Enass Y A Salih
- Faculty of Agriculture and Forestry, Department of Forest Sciences, Viikki Tropical Resources Institute, University of Helsinki, P.O. Box 27, FIN-00014, Finland; Faculty of Pharmacy, Division of Pharmaceutical Biosciences, Viikki Biocenter, University of Helsinki, P.O. Box 56, FIN-00014, Finland.
| | - Riitta Julkunen-Tiitto
- Faculty of Science and Forestry, Department of Environmental and Biological Sciences, University of Eastern Finland, 80101 Joensuu, Finland
| | - Anna-Maija Lampi
- Faculty of Agriculture and Forestry, Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 27, Latokartanonkaari 11, FI-00014 Helsinki, Finland
| | - Markku Kanninen
- Faculty of Agriculture and Forestry, Department of Forest Sciences, Viikki Tropical Resources Institute, University of Helsinki, P.O. Box 27, FIN-00014, Finland
| | - Olavi Luukkanen
- Faculty of Agriculture and Forestry, Department of Forest Sciences, Viikki Tropical Resources Institute, University of Helsinki, P.O. Box 27, FIN-00014, Finland
| | - Marketta Sipi
- Faculty of Agriculture and Forestry, Department of Forest Sciences, Viikki Tropical Resources Institute, University of Helsinki, P.O. Box 27, FIN-00014, Finland
| | - Mari Lehtonen
- Faculty of Agriculture and Forestry, Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 27, Latokartanonkaari 11, FI-00014 Helsinki, Finland
| | - Heikki Vuorela
- Faculty of Pharmacy, Division of Pharmaceutical Biosciences, Viikki Biocenter, University of Helsinki, P.O. Box 56, FIN-00014, Finland
| | - Pia Fyhrquist
- Faculty of Pharmacy, Division of Pharmaceutical Biosciences, Viikki Biocenter, University of Helsinki, P.O. Box 56, FIN-00014, Finland.
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16
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Uhía I, Priestman M, Joyce G, Krishnan N, Shahrezaei V, Robertson BD. Analysis of ParAB dynamics in mycobacteria shows active movement of ParB and differential inheritance of ParA. PLoS One 2018; 13:e0199316. [PMID: 29920558 PMCID: PMC6007833 DOI: 10.1371/journal.pone.0199316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 06/05/2018] [Indexed: 01/16/2023] Open
Abstract
Correct chromosomal segregation, coordinated with cell division, is crucial for bacterial survival, but despite extensive studies, the mechanisms underlying this remain incompletely understood in mycobacteria. We report a detailed investigation of the dynamic interactions between ParA and ParB partitioning proteins in Mycobacterium smegmatis using microfluidics and time-lapse fluorescence microscopy to observe both proteins simultaneously. During growth and division, ParB presents as a focused fluorescent spot that subsequently splits in two. One focus moves towards a higher concentration of ParA at the new pole, while the other moves towards the old pole. We show ParB movement is in part an active process that does not rely on passive movement associated with cell growth. In some cells, another round of ParB segregation starts before cell division is complete, consistent with initiation of a second round of chromosome replication. ParA fluorescence distribution correlates with cell size, and in sister cells, the larger cell inherits a local peak of concentrated ParA, while the smaller sister inherits more homogeneously distributed protein. Cells which inherit more ParA grow faster than their sister cell, raising the question of whether inheritance of a local concentration of ParA provides a growth advantage. Alterations in levels of ParA and ParB were also found to disturb cell growth.
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Affiliation(s)
- Iria Uhía
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Miles Priestman
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Graham Joyce
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Nitya Krishnan
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Vahid Shahrezaei
- Department of Mathematics, Imperial College London, London, United Kingdom
| | - Brian D. Robertson
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
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Dow A, Prisic S. Alternative ribosomal proteins are required for growth and morphogenesis of Mycobacterium smegmatis under zinc limiting conditions. PLoS One 2018; 13:e0196300. [PMID: 29684089 PMCID: PMC5912738 DOI: 10.1371/journal.pone.0196300] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/10/2018] [Indexed: 01/19/2023] Open
Abstract
Zinc is an essential micronutrient required for proper structure and function of many proteins. Bacteria regularly encounter zinc depletion and have evolved diverse mechanisms to continue growth when zinc is limited, including the expression of zinc-independent paralogs of zinc-binding proteins. Mycobacteria have a conserved operon encoding four zinc-independent alternative ribosomal proteins (AltRPs) that are expressed when zinc is depleted. It is unknown if mycobacterial AltRPs replace their primary paralogs in the ribosome and maintain protein synthesis under zinc-limited conditions, and if such replacements contribute to their physiology. This study shows that AltRPs from Mycobacterium smegmatis are essential for growth when zinc ion is scarce. Specifically, the deletion mutant of this operon (ΔaltRP) is unable to grow in media containing a high-affinity zinc chelator, while growth of the wild type strain is unaffected under the same conditions. However, when zinc is gradually depleted during growth in zinc-limited medium, the ΔaltRP mutant maintains the same growth rate as seen for the wild type strain. In contrast to M. smegmatis grown with sufficient zinc supplementation that forms shorter cells when transitioning from logarithmic to stationary phase, M. smegmatis deficient for zinc elongates after the expression of AltRPs in late logarithmic phase. These zinc-depleted bacteria also exhibit a remarkable morphology characterized by a condensed chromosome, increased number of polyphosphate granules, and distinct appearance of lipid bodies and the cell wall compared to the zinc-replete cells. However, the ΔaltRP cells fail to elongate and transition into the zinc-limited morphotype, resembling the wild type zinc-replete bacteria instead. Therefore, the altRP operon in M. smegmatis has a vital role in continuation of growth when zinc is scarce and in triggering specific morphogenesis during the adaptation to zinc limitation, suggesting that AltRPs can functionally replace their zinc-dependent paralogs, but also contribute to mycobacterial physiology in a unique way.
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Affiliation(s)
- Allexa Dow
- Department of Microbiology, University of Hawai‛i at Mānoa, Honolulu, Hawai‛i, United States of America
| | - Sladjana Prisic
- Department of Microbiology, University of Hawai‛i at Mānoa, Honolulu, Hawai‛i, United States of America
- * E-mail:
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18
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Abstract
Ergothioneine (ERG) is a histidine-derived thiol compound suggested to function as an antioxidant and cytoprotectant in humans. Therefore, experimental trials have been conducted applying ERG from mushrooms in dietary supplements and as a cosmetic additive. However, this method of producing ERG is expensive; therefore, alternative methods for ERG supply are required. Five Mycobacterium smegmatis genes, egtABCDE, have been confirmed to be responsible for ERG biosynthesis. This enabled us to develop practical fermentative ERG production by microorganisms. In this study, we carried out heterologous and high-level production of ERG in Escherichia coli using the egt genes from M. smegmatis. By high production of each of the Egt enzymes and elimination of bottlenecks in the substrate supply, we succeeded in constructing a production system that yielded 24 mg/L (104 μM) secreted ERG.
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Affiliation(s)
| | | | | | - Yusuke Kawano
- Innovation Medical Research Institute, University of Tsukuba , Tsukuba, Ibaraki 305-8550, Japan
| | - Iwao Ohtsu
- Innovation Medical Research Institute, University of Tsukuba , Tsukuba, Ibaraki 305-8550, Japan
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Fomogne-Fodjo MCY, Ndinteh DT, Olivier DK, Kempgens P, van Vuuren S, Krause RWM. Secondary metabolites from Tetracera potatoria stem bark with anti-mycobacterial activity. J Ethnopharmacol 2017; 195:238-245. [PMID: 27864111 DOI: 10.1016/j.jep.2016.11.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/25/2016] [Accepted: 11/13/2016] [Indexed: 06/06/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tetracera potatoria Afzel. Exg. Don (Dilleniaceae) is a medicinal plant used traditionally in Africa for the treatment of tuberculosis related ailments and respiratory infections. The antibacterial activity of the medium polar extracts of T. potatoria leaves and stem bark was recently reported against Mycobacterium smegmatis (MIC 25µg/mL) and M. aurum (65µg/mL), two fast-growing Mycobacterium strains used as model micro-organisms for the more pathogenic strain Mycobacterium tuberculosis (Fomogne-Fodjo et al., 2014). The aim of this study was consequently to isolate the compounds possibly contributing to this activity, and which may therefore be promising precursors to be used for the development of novel anti-TB drugs. MATERIALS AND METHODS T. potatoria medium polar extract [MeOH/DCM (1:1, v/v)] was fractionated sequentially with petroleum ether to which EtOAC and MeOH were gradually added to increase the polarity. The examination of T. potatoria extract and its fractions was guided by bioassays for anti-mycobacterial activity against M. smegmatis (ATCC 23246) and M. aurum (NCTC 10437) using the minimum inhibitory concentration (MIC) method. All the isolated compounds were structurally elucidated using spectroscopic techniques and evaluated for their anti-mycobacterial activity. RESULTS Two novel secondary metabolites (1, 2) named tetraceranoate and N-hydroxy imidate-tetracerane, together with five known compounds [β-stigmasterol (3), stigmast-5-en-3β-yl acetate (4), betulinic acid (5), betulin (6) and lupeol (7)] were isolated and identified. Tetraceranoate exhibited the best activity against M. smegmatis with a minimum inhibitory concentration (MIC) of 7.8µg/mL, while β-stigmasterol, betulinic acid and betulin showed appreciable anti-mycobacterial activity against both strains (MIC 15µg/mL). CONCLUSION Seven compounds were isolated from the medium polar extract [MeOH/DCM (1:1, v/v)] of T. potatoria stem bark. Only tetraceranoate one of the isolated compounds showed antibacterial activity against M. smegmatis having efficacy as high as rifampicin (one of a three drug regimen recommended in the initial phase short-course anti-tuberculosis therapy). Thus, tetraceranoate might be an interesting target for systematic testing of anti-TB treatment and management. This research supports the use of T. potatoria in African traditional medicine for the treatment of tuberculosis related symptoms.
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Affiliation(s)
- M C Y Fomogne-Fodjo
- Department of Chemistry, Rhodes University, PO Box 94, Grahamstown 6140, South Africa.
| | - D T Ndinteh
- Department of Applied Chemistry, University of Johannesburg, PO Box 17011, Doornfontein, Johannesburg 2028, South Africa
| | - D K Olivier
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa
| | - P Kempgens
- Department of Chemistry, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
| | - S van Vuuren
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa
| | - R W M Krause
- Department of Chemistry, Rhodes University, PO Box 94, Grahamstown 6140, South Africa.
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Coronado-Aceves EW, Sánchez-Escalante JJ, López-Cervantes J, Robles-Zepeda RE, Velázquez C, Sánchez-Machado DI, Garibay-Escobar A. Antimycobacterial activity of medicinal plants used by the Mayo people of Sonora, Mexico. J Ethnopharmacol 2016; 190:106-115. [PMID: 27262564 DOI: 10.1016/j.jep.2016.05.064] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/24/2016] [Accepted: 05/31/2016] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tuberculosis (TB) is an infectious disease mainly caused by Mycobacterium tuberculosis (Mtb), which generates 9 million new cases worldwide each year. The Mayo ethnicity of southern Sonora, Mexico is more than 2000 years old, and the Mayos possess extensive knowledge of traditional medicine. AIMS OF THE STUDY To evaluate the antimycobacterial activity levels of extracts of medicinal plants used by the Mayos against Mtb and Mycobacterium smegmatis (Msm) in the treatment of TB, respiratory diseases and related symptoms. MATERIALS AND METHODS A total of 34 plant species were collected, and 191 extracts were created with n-hexane, dichloromethane, ethyl acetate (EtOAc), methanol and water. Their minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined against Mtb H37Rv using the microplate alamar blue assay (MABA) and against Msm using the resazurin microplate assay (REMA) at 6 and 2 days of exposure, respectively, and at concentrations of 250-1.9µg/mL (n-hexane extracts) and 1000-7.81µg/mL (extracts obtained with dichloromethane, EtOAc, methanol and water). RESULTS Rhynchosia precatoria (Willd.) DC. (n-hexane root extract), Euphorbia albomarginata Torr. and A. Gray. (EtOAc shoot extract) and Helianthus annuus L. (n-hexane stem extract) were the most active plants against Mtb H37Rv, with MICs of 15.6, 250, 250µg/mL and MBCs of 31.25, 250, 250µg/mL, respectively. R. precatoria (root) was the only active plant against Msm, with MIC and MBC values of ≥250µg/mL. None of the aqueous extracts were active. CONCLUSIONS This study validates the medicinal use of certain plants used by the Mayo people in the treatment of TB and related symptoms. R. precatoria, E. albomarginata and H. annuus are promising plant sources of active compounds that act against Mtb H37Rv. To our knowledge, this is the first time that their antimycobacterial activity has been reported. Crude extracts obtained with n-hexane, EtOAc and dichloromethane were the most active against Mtb H37Rv.
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Affiliation(s)
- Enrique Wenceslao Coronado-Aceves
- Departamento de Biotecnología y Ciencias Alimentarias, Instituto Tecnológico de Sonora, 5 de Febrero 818 Sur, 85000 Ciudad Obregón, Sonora, Mexico
| | - José Jesús Sánchez-Escalante
- Herbario USON, Departamento de Investigaciones Científicas y Tecnológicas, Universidad de Sonora, Niños Héroes entre Rosales y José María Pino Suárez, Edificio 1A (Museo), Colonia Centro, 83000 Hermosillo, Sonora, Mexico
| | - Jaime López-Cervantes
- Departamento de Biotecnología y Ciencias Alimentarias, Instituto Tecnológico de Sonora, 5 de Febrero 818 Sur, 85000 Ciudad Obregón, Sonora, Mexico
| | - Ramón Enrique Robles-Zepeda
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Encinas y Rosales, Colonia Centro, 83000 Hermosillo, Sonora, Mexico
| | - Carlos Velázquez
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Encinas y Rosales, Colonia Centro, 83000 Hermosillo, Sonora, Mexico
| | - Dalia Isabel Sánchez-Machado
- Departamento de Biotecnología y Ciencias Alimentarias, Instituto Tecnológico de Sonora, 5 de Febrero 818 Sur, 85000 Ciudad Obregón, Sonora, Mexico
| | - Adriana Garibay-Escobar
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Encinas y Rosales, Colonia Centro, 83000 Hermosillo, Sonora, Mexico.
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Garcia-Aguilar T, Espinosa-Cueto P, Magallanes-Puebla A, Mancilla R. The Mannose Receptor Is Involved in the Phagocytosis of Mycobacteria-Induced Apoptotic Cells. J Immunol Res 2016; 2016:3845247. [PMID: 27413759 PMCID: PMC4931060 DOI: 10.1155/2016/3845247] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 05/18/2016] [Accepted: 05/24/2016] [Indexed: 11/17/2022] Open
Abstract
Upon Mycobacterium tuberculosis infection, macrophages may undergo apoptosis, which has been considered an innate immune response. The pathways underlying the removal of dead cells in homeostatic apoptosis have been extensively studied, but little is known regarding how cells that undergo apoptotic death during mycobacterial infection are removed. This study shows that macrophages induced to undergo apoptosis with mycobacteria cell wall proteins are engulfed by J-774A.1 monocytic cells through the mannose receptor. This demonstration was achieved through assays in which phagocytosis was inhibited with a blocking anti-mannose receptor antibody and with mannose receptor competitor sugars. Moreover, elimination of the mannose receptor by a specific siRNA significantly diminished the expression of the mannose receptor and the phagocytosis of apoptotic cells. As shown by immunofluorescence, engulfed apoptotic bodies are initially located in Rab5-positive phagosomes, which mature to express the phagolysosome marker LAMP1. The phagocytosis of dead cells triggered an anti-inflammatory response with the production of TGF-β and IL-10 but not of the proinflammatory cytokines IL-12 and TNF-α. This study documents the previously unreported participation of the mannose receptor in the removal of apoptotic cells in the setting of tuberculosis (TB) infection. The results challenge the idea that apoptotic cell phagocytosis in TB has an immunogenic effect.
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Affiliation(s)
- Teresa Garcia-Aguilar
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, DF, Mexico
| | - Patricia Espinosa-Cueto
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, DF, Mexico
| | - Alejandro Magallanes-Puebla
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, DF, Mexico
| | - Raúl Mancilla
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, DF, Mexico
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Li Q, Ge F, Tan Y, Zhang G, Li W. Genome-Wide Transcriptome Profiling of Mycobacterium smegmatis MC² 155 Cultivated in Minimal Media Supplemented with Cholesterol, Androstenedione or Glycerol. Int J Mol Sci 2016; 17:ijms17050689. [PMID: 27164097 PMCID: PMC4881515 DOI: 10.3390/ijms17050689] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/12/2016] [Accepted: 04/28/2016] [Indexed: 11/16/2022] Open
Abstract
Mycobacterium smegmatis strain MC² 155 is an attractive model organism for the study of M. tuberculosis and other mycobacterial pathogens, as it can grow well using cholesterol as a carbon resource. However, its global transcriptomic response remains largely unrevealed. In this study, M. smegmatis MC² 155 cultivated in androstenedione, cholesterol and glycerol supplemented media were collected separately for a RNA-Sequencing study. The results showed that 6004, 6681 and 6348 genes were expressed in androstenedione, cholesterol and glycerol supplemented media, and 5891 genes were expressed in all three conditions, with 237 specially expressed in cholesterol added medium. A total of 1852 and 454 genes were significantly up-regulated by cholesterol compared with the other two supplements. Only occasional changes were observed in basic carbon and nitrogen metabolism, while almost all of the genes involved in cholesterol catabolism and mammalian cell entry (MCE) were up-regulated by cholesterol, but not by androstenedione. Eleven and 16 gene clusters were induced by cholesterol when compared with glycerol or androstenedione, respectively. This study provides a comprehensive analysis of the cholesterol responsive transcriptome of M. smegmatis. Our results indicated that cholesterol induced many more genes and increased the expression of the majority of genes involved in cholesterol degradation and MCE in M. smegmatis, while androstenedione did not have the same effect.
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Affiliation(s)
- Qun Li
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China.
| | - Fanglan Ge
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China.
| | - Yunya Tan
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China.
| | - Guangxiang Zhang
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China.
| | - Wei Li
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China.
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Tan Y, Xu Z, Tao J, Ni J, Zhao W, Lu J, Yao YF. A SIRT4-like auto ADP-ribosyltransferase is essential for the environmental growth of Mycobacterium smegmatis. Acta Biochim Biophys Sin (Shanghai) 2016; 48:145-52. [PMID: 26685303 DOI: 10.1093/abbs/gmv121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 09/26/2015] [Indexed: 01/12/2023] Open
Abstract
SIRT family proteins are highly conserved both in the structure and function among all the organisms, and are involved in gene silencing, DNA damage repair, cell growth and metabolism. Here, a SIRT4 homologue MSMEG_4620 was identified and characterized in Mycobacterium smegmatis. MSMEG_4620 exhibits deacetylase activity that can be activated by fatty acids. Interestingly, MSMEG_4620 also possesses auto ADP-ribosylation activity. MSMEG_4620 is modified on arginine residues as revealed by a chemical stability assay. Moreover, the auto ADP-ribosylation activity of MSMEG_4620 was found to be enhanced by ferric ion. Notably, the SIRT4 homologues are widely distributed in the genomes of environmental mycobacterial species instead of pathogenic mycobacterial species. When MSMEG_4620 was deleted in M. smegmatis, the mutant strain showed a growth defect in 7H9 minimal medium compared with the parental strain. Taken together, these results provided the characteristics of a SIRT4 homologue in prokaryotes and implicated its critical roles in the growth of environmental mycobacterial species.
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Affiliation(s)
- Yongcong Tan
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zhihong Xu
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jing Tao
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jinjing Ni
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wei Zhao
- Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jie Lu
- Department of Infectious Diseases, Shanghai Ruijin Hospital, Shanghai 200025, China
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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24
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Ravishankar S, Ambady A, Swetha RG, Anbarasu A, Ramaiah S, Sambandamurthy VK. Essentiality Assessment of Cysteinyl and Lysyl-tRNA Synthetases of Mycobacterium smegmatis. PLoS One 2016; 11:e0147188. [PMID: 26794499 PMCID: PMC4721953 DOI: 10.1371/journal.pone.0147188] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/30/2015] [Indexed: 12/02/2022] Open
Abstract
Discovery of mupirocin, an antibiotic that targets isoleucyl-tRNA synthetase, established aminoacyl-tRNA synthetase as an attractive target for the discovery of novel antibacterial agents. Despite a high degree of similarity between the bacterial and human aminoacyl-tRNA synthetases, the selectivity observed with mupirocin triggered the possibility of targeting other aminoacyl-tRNA synthetases as potential drug targets. These enzymes catalyse the condensation of a specific amino acid to its cognate tRNA in an energy-dependent reaction. Therefore, each organism is expected to encode at least twenty aminoacyl-tRNA synthetases, one for each amino acid. However, a bioinformatics search for genes encoding aminoacyl-tRNA synthetases from Mycobacterium smegmatis returned multiple genes for glutamyl (GluRS), cysteinyl (CysRS), prolyl (ProRS) and lysyl (LysRS) tRNA synthetases. The pathogenic mycobacteria, namely, Mycobacterium tuberculosis and Mycobacterium leprae, were also found to possess two genes each for CysRS and LysRS. A similar search indicated the presence of additional genes for LysRS in gram negative bacteria as well. Herein, we describe sequence and structural analysis of the additional aminoacyl-tRNA synthetase genes found in M. smegmatis. Characterization of conditional expression strains of Cysteinyl and Lysyl-tRNA synthetases generated in M. smegmatis revealed that the canonical aminoacyl-tRNA synthetase are essential, while the additional ones are not essential for the growth of M. smegmatis.
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Affiliation(s)
- Sudha Ravishankar
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bengaluru, 560024, India
- * E-mail:
| | - Anisha Ambady
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bengaluru, 560024, India
| | - Rayapadi G. Swetha
- School of Biosciences & Technology, VIT University, Vellore, 632014, India
| | - Anand Anbarasu
- School of Biosciences & Technology, VIT University, Vellore, 632014, India
| | - Sudha Ramaiah
- School of Biosciences & Technology, VIT University, Vellore, 632014, India
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Karpenko IL, Sorokoumova GM, Sumarukova IG, Gaydukevich SK, Zaretskaya MA, Efremenkova OV, Alexandrova LA. Development of Liposomal Forms of Modified Pyrimidine Nucleosides and Investigation of Their Antibacterial Properties. Antibiot Khimioter 2016; 61:9-15. [PMID: 29558055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Different phosphocholine-cardiolipin-2'-deoxyuridine inclusion complexes were developed, that allowed to compose a water-soluble form of nucleoside analogues with previously defined antituberculosis activity. It was found that the resulting liposomes effectively penetrated to the cells. The increase of cytotoxicity was undoubtedly indicative of accumulation of the nucleoside in the cell culture. The result proved the ability of the liposomes for delivery of the low-soluble compounds to the cells for further investigation of their efficacy. It was shown that treatment of the bacterial cells with the llposomes of the modified nucleosides did not affect the bacterial growth.
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26
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Dixit PP, Dixit PP, Thore SN. Hybrid triazoles: Design and synthesis as potential dual inhibitor of growth and efflux inhibition in tuberculosis. Eur J Med Chem 2015; 107:38-47. [PMID: 26562541 DOI: 10.1016/j.ejmech.2015.10.054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 10/27/2015] [Accepted: 10/30/2015] [Indexed: 11/19/2022]
Abstract
Efflux inhibition is proven bacterial machinery responsible for removal of bacterial wastage including antibiotics. Recently, efflux inhibitors (EI) have been tested with encouraging results as an adjuvant therapy for treatment of tuberculosis (TB). Although, EI have emerged as innovative approach of treatment for multi drug resistant (MDR) & extensively drug resistant tuberculosis (XDR-TB), toxicity profile limits their wider use. To address this issue, we have attempted synthesizing hybrid molecules those results by combining known EI and triazole. This synthesis was aimed to arrive at structure that possesses pharmacophore from known EI. Synthesized molecules were evaluated as growth inhibitors (GI) and Efflux inhibitor of TB initially against Mycobacterium smegmatis mc(2)155. Pharmacologically active compounds were then tested for their cytotoxicity to further narrow down search. Most active compounds 144, 145, 154 and 163 were then tested for their GEI action against Mycobacterium tuberculosis (Mtb). Synthesized compounds were also tested for their synergistic action with first line and second line anti-TB drugs and ethidium bromide (EtBr). We arrived at compound 135 as most potent dual inhibitor of tuberculosis.
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Affiliation(s)
- Prasad P Dixit
- Department of Chemistry, Vinayakrao Patil Mahavidyalaya, Vaijapur, 423701 Dist Aurangabad, Maharashtra, India
| | - Prashant P Dixit
- Department of Microbiology, Dr. Babasaheb Ambedkar Marathwada University, Sub-Center, Osmanabad, 413501, Dist. Osmanabad, Maharashtra, India
| | - Shivajirao N Thore
- Department of Chemistry, Vinayakrao Patil Mahavidyalaya, Vaijapur, 423701 Dist Aurangabad, Maharashtra, India.
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27
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Alvi A, Fatima N, Jerah AA, Rizwan M, Hobani YH, Sunosi RA, Taha MMEH, Habiballah EM, Agarwal PK, Abdulwahab SI. Correlation between Resistin, Tuberculosis and Khat Addiction: A Study from South Western Province of Saudi Arabia. PLoS One 2015; 10:e0140245. [PMID: 26448186 PMCID: PMC4598132 DOI: 10.1371/journal.pone.0140245] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 09/23/2015] [Indexed: 11/19/2022] Open
Abstract
Tuberculosis(TB) is a disease of global significance, which accounts for a death in every 15 seconds. Recent studies shows TB is rising in certain parts of the world, and Saudi Arabia is one of them. Several factor contribute in predisposing the subjects for infection including but not limited to addiction to various compounds which have immune modulation properties, such as amphetamines and Heroin etc. Khat a plant whose leaves are chewed for its euphoric effect in east Africa and Arabian Peninsula including Saudi Arabia, is considered as mildly addictive, and its principle compound, Cathinone shares structural and functional similarity with amphetamine a known immunomodulator. Tuberculosis being a disease of immune modulation has a varied spectrum of complex interplay of proinflammatory molecules, resistin is one of them. In the present study, we try to explore the trinity of khat addiction, serum resistin level and tuberculosis by correlating the serum resistin level in non khat addicted healthy subjects, khat addicted healthy subjects, and in patients, both khat addicted and non khat addicted, with active tuberculosis. We observed significantly higher resistin level among the apparently healthy khat addicted subjects as compared to non addicted healthy controls. Thereafter, when we compare the resistin levels between khat addicted and non khat addicted TB patients we did not found significant difference between the two groups. However bacillary load was observe to be significantly higher among the khat addicted TB patient as compare to non addicted one. Validation of above results in animal model revealed dose dependant increase in bacillary growth in the Wistar rats treated with khat. Taken together these results suggest the role of khat in immune modulation albeit in the limited frame of resistin level.
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Affiliation(s)
- Ayesha Alvi
- Department of Genetics and Molecular Biology, Faculty of Applied Medical Sciences, Jazan University, Jazan, KSA
- * E-mail:
| | - Nuzhath Fatima
- Department of Microbiology, Faculty of Applied Medical Sciences, Jazan University, Jazan, KSA
| | - Ahmed Ali Jerah
- Department of Biochemistry, Faculty of Applied Medical Sciences, Jazan University, Jazan, KSA
| | - Mohammed Rizwan
- Department of Biochemistry, College of Nursing, Jazan University, Jazan, KSA
| | - Yahya Hasan Hobani
- Department of Genetics and Molecular Biology, Faculty of Applied Medical Sciences, Jazan University, Jazan, KSA
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Abstract
Tuberculosis (TB) is the world's deadliest curable disease, responsible for an estimated 1.5 million deaths annually. A considerable challenge in controlling this disease is the prolonged multidrug chemotherapy (6 to 9 months) required to overcome drug-tolerant mycobacteria that persist in human tissues, although the same drugs can sterilize genetically identical mycobacteria growing in axenic culture within days. An essential component of TB infection involves intracellular Mycobacterium tuberculosis bacteria that multiply within macrophages and are significantly more tolerant to antibiotics compared to extracellular mycobacteria. To investigate this aspect of human TB, we created a physical cell culture system that mimics confinement of replicating mycobacteria, such as in a macrophage during infection. Using this system, we uncovered an epigenetic drug-tolerance phenotype that appears when mycobacteria are cultured in space-confined bioreactors and disappears in larger volume growth contexts. Efflux mechanisms that are induced in space-confined growth environments contribute to this drug-tolerance phenotype. Therefore, macrophage-induced drug tolerance by mycobacteria may be an effect of confined growth among other macrophage-specific mechanisms.
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Affiliation(s)
- Brilliant B. Luthuli
- KwaZulu-Natal Research Institute for Tuberculosis and HIV, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Georgiana E. Purdy
- Dept. of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 S. W. Sam Jackson Park Rd., Mail Code L220, Portland, OR, 97239, United States of America
| | - Frederick K. Balagaddé
- KwaZulu-Natal Research Institute for Tuberculosis and HIV, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, 4001, South Africa
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29
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Ravishankar S, Ambady A, Ramu H, Mudugal NV, Tunduguru R, Anbarasu A, Sharma UK, Sambandamurthy VK, Ramaiah S. An IPTG Inducible Conditional Expression System for Mycobacteria. PLoS One 2015; 10:e0134562. [PMID: 26247874 PMCID: PMC4527713 DOI: 10.1371/journal.pone.0134562] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 07/12/2015] [Indexed: 12/21/2022] Open
Abstract
Conditional expression strains serve as a valuable tool to study the essentiality and to establish the vulnerability of a target under investigation in a drug discovery program. While essentiality implies an absolute requirement of a target function, vulnerability provides valuable information on the extent to which a target function needs to be depleted to achieve bacterial growth inhibition followed by cell death. The critical feature of an ideal conditional expression system is its ability to tightly regulate gene expression to achieve the full spectrum spanning from a high level of expression in order to support growth and near zero level of expression to mimic conditions of gene knockout. A number of bacterial conditional expression systems have been reported for use in mycobacteria. The utility of an isopropylthiogalactoside (IPTG) inducible system in mycobacteria has been reported for protein overexpression and anti-sense gene expression from a replicating multi-copy plasmid. Herein, we report the development of a versatile set of non-replicating IPTG inducible vectors for mycobacteria which can be used for generation of conditional expression strains through homologous recombination. The role of a single lac operator versus a double lac operator to regulate gene expression was evaluated by monitoring the expression levels of β-galactosidase in Mycobacterium smegmatis. These studies indicated a significant level of leaky expression from the vector with a single lac operator but none from the vector with double lac operator. The significance of the double lac operator vector for target validation was established by monitoring the growth kinetics of an inhA, a rpoB and a ftsZ conditional expression strain grown in the presence of different concentrations of IPTG. The utility of this inducible system in identifying target specific inhibitors was established by screening a focussed library of small molecules using an inhA and a rpoB conditional expression strain.
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Affiliation(s)
- Sudha Ravishankar
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bengaluru, Karnataka, India
- * E-mail:
| | - Anisha Ambady
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bengaluru, Karnataka, India
| | - Haripriya Ramu
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bengaluru, Karnataka, India
| | - Naina Vinay Mudugal
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bengaluru, Karnataka, India
| | | | - Anand Anbarasu
- School of Biosciences & Technology, VIT University, Vellore, Tamil Nadu, India
| | - Umender K. Sharma
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bengaluru, Karnataka, India
| | | | - Sudha Ramaiah
- School of Biosciences & Technology, VIT University, Vellore, Tamil Nadu, India
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Abstract
Hydrogen peroxide (H2O2) is a natural oxidant produced by aerobic organisms and gives rise to oxidative damage, including DNA mutations, protein inactivation and lipid damage. The genus Mycobacterium utilizes redox sensors and H2O2 scavenging enzymes for the detoxification of H2O2. To date, the precise response to oxidative stress has not been fully elucidated. Here, we compared the effects of different levels of H2O2 on transcription in M. smegmatis using RNA-sequencing. A 0.2 mM H2O2 treatment had little effect on the growth and viability of M. smegmatis whereas 7 mM H2O2 was lethal. Analysis of global transcription showed that 0.2 mM H2O2 induced relatively few changes in gene expression, whereas a large proportion of the mycobacterial genome was found to be differentially expressed after treatment with 7 mM H2O2. Genes differentially expressed following treatment with 0.2 mM H2O2 included those coding for proteins involved in glycolysis-gluconeogenesis and fatty acid metabolism pathways, and expression of most genes encoding ribosomal proteins was lower following treatment with 7 mM H2O2. Our analysis shows that M. smegmatis utilizes the sigma factor MSMEG_5214 in response to 0.2 mM H2O2, and the RpoE1 sigma factors MSMEG_0573 and MSMEG_0574 in response to 7 mM H2O2. In addition, different transcriptional regulators responded to different levels of H2O2: MSMEG_1919 was induced by 0.2 mM H2O2, while high-level induction of DevR occurred in response to 7 mM H2O2. We detected the induction of different detoxifying enzymes, including genes encoding KatG, AhpD, TrxB and Trx, at different levels of H2O2 and the detoxifying enzymes were expressed at different levels of H2O2. In conclusion, our study reveals the changes in transcription that are induced in response to different levels of H2O2 in M. smegmatis.
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Affiliation(s)
- Xiaojing Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, CAS, Beijing, 100101, China
- Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing 100101, Beijing, China
| | - Jun Wu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, CAS, Beijing, 100101, China
- Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing 100101, Beijing, China
| | - Jiao Han
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, CAS, Beijing, 100101, China
| | - Yongfei Hu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, CAS, Beijing, 100101, China
- Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing 100101, Beijing, China
| | - Kaixia Mi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, CAS, Beijing, 100101, China
- Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing 100101, Beijing, China
- * E-mail:
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Alam P, Al-Anezi M, Siddiqui NA, Alajmi MF, Al-Rehaily AJ, Haque A, Ali M. Isolation and characterization of a new oxygenated homoditerpenoid from leaves of Centaurothamnus maximus with antimicrobial potential. Pak J Pharm Sci 2015; 28:1091-1095. [PMID: 26051729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A new bioactive oxygenated homoditerpenic compound along with one known compound from the antimicrobial active ethanol extract of leaves of an endemic plant Centaurothamnus maximus was isolated. The n -hexane, dichloromethane, ethyl acetate and ethanol fractions of C. maximus leaves were evaluated for their antimicrobial potential by using standard agar well diffusion method against various microorganisms viz. B. subtilis, S. aureus, E. coli, P. aeruginosa, C. albicans and M. smegmatis. The results revealed that only ethanol extract was active against all microbes except the fungus C. albicans. A new compound 2α, 3α-dihydroxy-8α-methoxy-15-hydroxy-methylene- pimar-5,9 (11)-diene (CM-1) was isolated along with a known compound α-D-xylose (CM-2) from ethanol extract by reverse phase (RP-18) column chromatography and 1D and 2D NMR (DEPT, COSY, HMBC and HSQC) aided by EIMS mass and IR spectra were used to establish the structure. CM-1 was found to be active against B. subtilis, S. aureus and M. smegmatis (P>0.005) at MIC 20 μg/ml. Findings of this study may provide a lead for synthesis of more potent antimicrobial agents to serve the humanity against multidrug-resistant bacterial infections.
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Affiliation(s)
- Perwez Alam
- Deptt. of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, KSA
| | - Mohammed Al-Anezi
- Deptt. of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, KSA
| | - Nasir Ali Siddiqui
- Deptt. of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, KSA
| | | | | | - Anzarul Haque
- Deptt.of Phytochemistry and Pharmacognosy, College of Pharmacy, Salman bin Abdul Aziz University, Al Kharj, KSA
| | - Mohammed Ali
- Deptt. of Pharmacognosy & Phytochemistry, Faculty of Pharmacy, JamiaHamdard, New Delhi, Indi
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Padwal P, Bandyopadhyaya R, Mehra S. Polyacrylic acid-coated iron oxide nanoparticles for targeting drug resistance in mycobacteria. Langmuir 2014; 30:15266-15276. [PMID: 25375643 DOI: 10.1021/la503808d] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The emergence of drug resistance is a major problem faced in current tuberculosis (TB) therapy, representing a global health concern. Mycobacterium is naturally resistant to most drugs due to export of the latter outside bacterial cells by active efflux pumps, resulting in a low intracellular drug concentration. Thus, development of agents that can enhance the effectiveness of drugs used in TB treatment and bypass the efflux mechanism is crucial. In this study, we present a new nanoparticle-based strategy for enhancing the efficacy of existing drugs. To that end, we have developed poly(acrylic acid) (PAA)-coated iron oxide (magnetite) nanoparticles (PAA-MNPs) as efflux inhibitors and used it together with rifampicin (a first line anti-TB drug) on Mycobacterium smegmatis. PAA-MNPs of mean diameter 9 nm interact with bacterial cells via surface attachment and are then internalized by cells. Although PAA-MNP alone does not inhibit cell growth, treatment of cells with a combination of PAA-MNP and rifampicin exhibits a synergistic 4-fold-higher growth inhibition compared to rifampicin alone. This is because the combination of PAA-MNP and rifampicin results in up to a 3-fold-increased accumulation of rifampicin inside the cells. This enhanced intracellular drug concentration has been explained by real-time transport studies on a common efflux pump substrate, ethidium bromide (EtBr). It is seen that PAA-MNP increases the accumulation of EtBr significantly and also minimizes the EtBr efflux in direct proportion to the PAA-MNP concentration. Our results thus illustrate that the addition of PAA-MNP with rifampicin may bypass the innate drug resistance mechanism of M. smegmatis. This generic strategy is also found to be successful for other anti-TB drugs, such as isoniazid and fluoroquinolones (e.g., norfloxacin), only when stabilized, coated nanoparticles (such as PAA-MNP) are used, not PAA or MNP alone. We hence establish coated nanoparticles as a new class of efflux inhibitors for potential therapeutic use.
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Affiliation(s)
- Priyanka Padwal
- Department of Chemical Engineering, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India
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Evangelopoulos D, Gupta A, Lack NA, Maitra A, ten Bokum AM, Kendall S, Sim E, Bhakta S. Characterisation of a putative AraC transcriptional regulator from Mycobacterium smegmatis. Tuberculosis (Edinb) 2014; 94:664-71. [PMID: 25443504 PMCID: PMC4266540 DOI: 10.1016/j.tube.2014.08.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 08/09/2014] [Accepted: 08/13/2014] [Indexed: 11/16/2022]
Abstract
MSMEG_0307 is annotated as a transcriptional regulator belonging to the AraC protein family and is located adjacent to the arylamine N-acetyltransferase (nat) gene in Mycobacterium smegmatis, in a gene cluster, conserved in most environmental mycobacterial species. In order to elucidate the function of the AraC protein from the nat operon in M. smegmatis, two conserved palindromic DNA motifs were identified using bioinformatics and tested for protein binding using electrophoretic mobility shift assays with a recombinant form of the AraC protein. We identified the formation of a DNA:AraC protein complex with one of the motifs as well as the presence of this motif in 20 loci across the whole genome of M. smegmatis, supporting the existence of an AraC controlled regulon. To characterise the effects of AraC in the regulation of the nat operon genes, as well as to gain further insight into its function, we generated a ΔaraC mutant strain where the araC gene was replaced by a hygromycin resistance marker. The level of expression of the nat and MSMEG_0308 genes was down-regulated in the ΔaraC strain when compared to the wild type strain indicating an activator effect of the AraC protein on the expression of the nat operon genes.
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Affiliation(s)
- Dimitrios Evangelopoulos
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Antima Gupta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Nathan A. Lack
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Arundhati Maitra
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Annemieke M.C. ten Bokum
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK
| | - Sharon Kendall
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK
| | - Edith Sim
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
- Corresponding author. Tel.: +44 (0)20 7631 6355 (office), +44 (0)20 7079 0799 (lab); fax: +44 (0)20 7631 6246.
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Huang L, Hu X, Tao J, Mi K. [A hemerythrin-like protein MSMEG_3312 influences erythromycin resistance in mycobacteria]. Wei Sheng Wu Xue Bao 2014; 54:1279-1288. [PMID: 25752134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE Reactive oxygen species are natural products of metabolism in aerobic organisms, which lead to oxidative damage, such as DNA mutation, protein inactivation and drug resistance. MSMEG_3312 was predicted as a hemerythrin-like protein, which can carry oxygen and reversibly bind to oxygen, thus it might play important roles in the process of oxygen metabolism. In this study, we explored the role of MSMEG_3312 in drug resistance. METHODS On the basis of bioinformatics, we identified the conserved sequence of HHE domain in MSMEG_3312 and it was predicted to have typical α-helix at secondary structure. To explore potential functions of MSMEG_3312, we constructed the msmeg_3312 knockout strain and compare the susceptibility to various drugs to its parent strain, mc2155. In addition, we also measured the promoter response when treatment of erythromycin. RESULTS Genetic results showed that MSMEG_3312 is not necessary for M. smegmatis growth at 7H9 rich medium. The msmeg_3312 knockout strain showed increased erythromycin resistance. Moreover, the drug resistance is only limited to erythromycin which its mechanism of action is by binding to the 50S subunit of the bacteria ribosomal complex and then inhibit protein synthesis. However, there were no different MICs of other antibiotics, targets for protein synthesis inhibition, but not 50S subunit, such as tetracyclines, aminoglycosides and chloramphenicol. Moreover, we also showed that the promoter of msmeg_3312 responses to erythromycin. CONCLUSIONS Hemerythin-like protein MSMEG_3312 is involved in erythromycin resistance.
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Hnilicová J, Jirát Matějčková J, Šiková M, Pospíšil J, Halada P, Pánek J, Krásný L. Ms1, a novel sRNA interacting with the RNA polymerase core in mycobacteria. Nucleic Acids Res 2014; 42:11763-76. [PMID: 25217589 PMCID: PMC4191392 DOI: 10.1093/nar/gku793] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/19/2014] [Accepted: 08/20/2014] [Indexed: 11/12/2022] Open
Abstract
Small RNAs (sRNAs) are molecules essential for a number of regulatory processes in the bacterial cell. Here we characterize Ms1, a sRNA that is highly expressed in Mycobacterium smegmatis during stationary phase of growth. By glycerol gradient ultracentrifugation, RNA binding assay, and RNA co-immunoprecipitation, we show that Ms1 interacts with the RNA polymerase (RNAP) core that is free of the primary sigma factor (σA) or any other σ factor. This contrasts with the situation in most other species where it is 6S RNA that interacts with RNAP and this interaction requires the presence of σA. The difference in the interaction of the two types of sRNAs (Ms1 or 6S RNA) with RNAP possibly reflects the difference in the composition of the transcriptional machinery between mycobacteria and other species. Unlike Escherichia coli, stationary phase M. smegmatis cells contain relatively few RNAP molecules in complex with σA. Thus, Ms1 represents a novel type of small RNAs interacting with RNAP.
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Affiliation(s)
- Jarmila Hnilicová
- Department of Molecular Genetics of Bacteria, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Jitka Jirát Matějčková
- Department of Molecular Genetics of Bacteria, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Michaela Šiková
- Department of Molecular Genetics of Bacteria, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Jiří Pospíšil
- Department of Molecular Genetics of Bacteria, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Petr Halada
- Department of Molecular Structure Characterization, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Josef Pánek
- Department of Bioinformatics, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Libor Krásný
- Department of Molecular Genetics of Bacteria, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
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Wang XM, Luo JK, Li Q, Li JY, Chen Y, Tao ZY, Xia H, Fang Q. [Construction and identification of recombinant Mycobacterium smegmatis vaccine expressing Cysticercus cellulosae cC1 antigen]. Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi 2014; 26:287-291. [PMID: 25345155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To construct recombinant Mycobacterium smegmatis vaccine expressing Cysticercus cellulosae cC1 antigen. METHODS The recombinant pET28a-cC1 plasmid was extracted and double digested by Xho I and BamH I restriction enzymes, and shuttle plasmid pMV261 was extracted and double digested by Hind III and BamH I restriction enzymes. Both fragments were modified by Klenow fragment to form blunt end, then the large fragments of cC1 and pMV261 plasmid were purified and ligated by T4 ligase enzyme. The recombinant pMV261-cC1 plasmid was constructed and sequenced. Then the pMV261-cC1 plasmid was transformed into Mycobacterium smegmatis by the electrotransformation method. The recombinant cC1-Mycobacterium smegmatis was induced by heat and identified by the Western blotting method with the sera of cysticercosis patients. In addition, the growth states of the Mycobacterium smegmatis and the recombinant cC1-Mycobacterium smegmatis were compared and the growth curves were drawn. RESULTS The restriction enzyme and sequencing results showed that the recombinant pMV261-cC1 plasmid was successfully constructed. After heat induction, a 40 kD band was showed by PAGE analysis of cC1-Mycobacterium smegmatis. The Western blotting results showed that the sera of cysticercosis patients could recognize the 40 kDa band, which suggested that cC1 protein was expressed in Mycobacterium smegmatis. Compared with the Mycobacterium smegmatis, the recombi- nant cC1-Mycobacterium smegmatis showed no significant difference in proliferation characteristics. CONCLUSION The recombinant cC1-Mycobacterium smegmatis vaccine has been successfully constructed.
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Staudinger T, Redl B, Glasgow BJ. Antibacterial activity of rifamycins for M. smegmatis with comparison of oxidation and binding to tear lipocalin. Biochim Biophys Acta 2014; 1844:750-8. [PMID: 24530503 PMCID: PMC3992280 DOI: 10.1016/j.bbapap.2014.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 01/28/2014] [Accepted: 02/03/2014] [Indexed: 11/19/2022]
Abstract
A mutant of Mycobacterium smegmatis is a potential class I model substitute for Mycobacterium tuberculosis. Because not all of the rifamycins have been tested in this organism, we determined bactericidal profiles for the 6 major rifamycin derivatives. The profiles closely mirrored those established for M. tuberculosis. Rifalazil was confirmed to be the most potent rifamycin. Because the tuberculous granuloma presents a harshly oxidizing environment we explored the effects of oxidation on rifamycins. Mass spectrometry confirmed that three of the six major rifamycins showed autoxidation in the presence of trace metals. Oxidation could be monitored by distinctive changes including isosbestic points in the ultraviolet-visible spectrum. Oxidation of rifamycins abrogated anti-mycobacterial activity in M. smegmatis. Protection from autoxidation was conferred by binding susceptible rifamycins to tear lipocalin, a promiscuous lipophilic protein. Rifalazil was not susceptible to autoxidation but was insoluble in aqueous solution. Solubility was enhanced when complexed to tear lipocalin and was accompanied by a spectral red shift. The positive solvatochromism was consistent with robust molecular interaction and binding. Other rifamycins also formed a complex with lipocalin, albeit to a lesser extent. Protection from oxidation and enhancement of solubility with protein binding may have implications for delivery of select rifamycin derivatives.
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Affiliation(s)
- Tamara Staudinger
- Department of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA; Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innrain 80-82, A-6020 Innsbruck, Austria
| | - Bernhard Redl
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innrain 80-82, A-6020 Innsbruck, Austria
| | - Ben J Glasgow
- Department of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA.
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Shleeva M, Goncharenko A, Kudykina Y, Young D, Young M, Kaprelyants A. Cyclic AMP-dependent resuscitation of dormant Mycobacteria by exogenous free fatty acids. PLoS One 2013; 8:e82914. [PMID: 24376605 PMCID: PMC3871856 DOI: 10.1371/journal.pone.0082914] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 10/29/2013] [Indexed: 12/26/2022] Open
Abstract
One third of the world population carries a latent tuberculosis (TB) infection, which may reactivate leading to active disease. Although TB latency has been known for many years it remains poorly understood. In particular, substances of host origin, which may induce the resuscitation of dormant mycobacteria, have not yet been described. In vitro models of dormant ("non-culturable") cells of Mycobacterium smegmatis (mc(2)155) and Mycobacterium tuberculosis H37Rv were used. We found that the resuscitation of dormant M. smegmatis and M. tuberculosis cells in liquid medium was stimulated by adding free unsaturated fatty acids (FA), including arachidonic acid, at concentrations of 1.6-10 µM. FA addition enhanced cAMP levels in reactivating M. smegmatis cells and exogenously added cAMP (3-10 mM) or dibutyryl-cAMP (0.5-1 mM) substituted for FA, causing resuscitation of M. smegmatis and M. tuberculosis dormant cells. A M. smegmatis null-mutant lacking MSMEG_4279, which encodes a FA-activated adenylyl cyclase (AC), could not be resuscitated by FA but it was resuscitated by cAMP. M. smegmatis and M. tuberculosis cells hyper-expressing AC were unable to form non-culturable cells and a specific inhibitor of AC (8-bromo-cAMP) prevented FA-dependent resuscitation. RT-PCR analysis revealed that rpfA (coding for resuscitation promoting factor A) is up-regulated in M. smegmatis in the beginning of exponential growth following the cAMP increase in lag phase caused by FA-induced cell activation. A specific Rpf inhibitor (4-benzoyl-2-nitrophenylthiocyanate) suppressed FA-induced resuscitation. We propose a novel pathway for the resuscitation of dormant mycobacteria involving the activation of adenylyl cyclase MSMEG_4279 by FAs resulted in activation of cellular metabolism followed later by increase of RpfA activity which stimulates cell multiplication in exponential phase. The study reveals a probable role for lipids of host origin in the resuscitation of dormant mycobacteria, which may function during the reactivation of latent TB.
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Affiliation(s)
- Margarita Shleeva
- Bach Institute of Biochemistry Russian Academy of Sciences, Moscow, Russia
| | - Anna Goncharenko
- Bach Institute of Biochemistry Russian Academy of Sciences, Moscow, Russia
| | - Yuliya Kudykina
- Bach Institute of Biochemistry Russian Academy of Sciences, Moscow, Russia
| | - Danielle Young
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Michael Young
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Arseny Kaprelyants
- Bach Institute of Biochemistry Russian Academy of Sciences, Moscow, Russia
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Mukherjee K, Mandal S, Mukhopadhyay B, Mandal NC, Sil AK. Bioactive compound from Pseudomonas synxantha inhibits the growth of Mycobacteria. Microbiol Res 2013; 169:794-802. [PMID: 24439826 DOI: 10.1016/j.micres.2013.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 12/06/2013] [Accepted: 12/10/2013] [Indexed: 11/17/2022]
Abstract
Tuberculosis is a dreaded disease and the current situation demands new anti-tubercular agent(s) for the management of public health. Towards this direction, we obtained a contaminant organism on a Mycobacterium smegmatis lawn having growth inhibitory activity against the later. In the current study, efforts were targeted to identify this organism and characterize the bioactive compound from this isolate that inhibited the growth of Mycobacteria. The result revealed that the organism is a strain of Pseudomonas synxantha. Biophysical analyses including (1)H and (13)C NMR, ESI-mass spectroscopy, FTIR showed that the bioactive compound is a long chain aliphatic hydrocarbon with a terminal alyl bond and intermediate electronegative atom. The compound exhibited strong growth inhibitory activities against M. smegmatis and Mycobacterium tuberculosis strains H37Ra, H37Rv and BCG. Further experiments showed that both P. synxantha and its secretory metabolites are capable of inducing hemolysis of human blood. Thus the results of this study clearly indicate that the bioactive compound produced by P. Synxantha has biosurfactant activities as well as anti-myco-bacterial properties.
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Affiliation(s)
- Koushik Mukherjee
- Department of Microbiology, University of Calcutta, 35, BC Road, Kolkata 700019, India
| | - Santanu Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research-Kolkata (IISER-K), Mohanpur Campus, Mohanpur Nadia-741252, India
| | - Balaram Mukhopadhyay
- Department of Chemical Sciences, Indian Institute of Science Education and Research-Kolkata (IISER-K), Mohanpur Campus, Mohanpur Nadia-741252, India
| | - Nitai Chandra Mandal
- Department of Biochemistry, Bose Institute, P 1/12, C.I.T. Road, Scheme, VIIM, Kolkata 700054, West Bengal, India
| | - Alok Kumar Sil
- Department of Microbiology, University of Calcutta, 35, BC Road, Kolkata 700019, India.
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García-Fernández E, Frank DJ, Galán B, Kells PM, Podust LM, García JL, Ortiz de Montellano PR. A highly conserved mycobacterial cholesterol catabolic pathway. Environ Microbiol 2013; 15:2342-59. [PMID: 23489718 PMCID: PMC3706556 DOI: 10.1111/1462-2920.12108] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 01/25/2013] [Accepted: 02/04/2013] [Indexed: 01/01/2023]
Abstract
Degradation of the cholesterol side-chain in Mycobacterium tuberculosis is initiated by two cytochromes P450, CYP125A1 and CYP142A1, that sequentially oxidize C26 to the alcohol, aldehyde and acid metabolites. Here we report characterization of the homologous enzymes CYP125A3 and CYP142A2 from Mycobacterium smegmatis mc(2) 155. Heterologously expressed, purified CYP125A3 and CYP142A2 bound cholesterol, 4-cholesten-3-one, and antifungal azole drugs. CYP125A3 or CYP142A2 reconstituted with spinach ferredoxin and ferredoxin reductase efficiently hydroxylated 4-cholesten-3-one to the C-26 alcohol and subsequently to the acid. The X-ray structures of both substrate-free CYP125A3 and CYP142A2 and of cholest-4-en-3-one-bound CYP142A2 reveal significant differences in the substrate binding sites compared with the homologous M. tuberculosis proteins. Deletion only of cyp125A3 causes a reduction of both the alcohol and acid metabolites and a strong induction of cyp142 at the mRNA and protein levels, indicating that CYP142A2 serves as a functionally redundant back up enzyme for CYP125A3. In contrast to M. tuberculosis, the M. smegmatis Δcyp125Δcyp142 double mutant retains its ability to grow on cholesterol albeit with a diminished capacity, indicating an additional level of redundancy within its genome.
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Affiliation(s)
- Esther García-Fernández
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Daniel J. Frank
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA USA
| | - Beatriz Galán
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Petrea M. Kells
- Department of Pathology and Center for Discovery and Innovation in Parasitic Diseases, University of California, San Francisco, CA USA
| | - Larissa M. Podust
- Department of Pathology and Center for Discovery and Innovation in Parasitic Diseases, University of California, San Francisco, CA USA
| | - José L. García
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
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Cox RA, Garcia MJ. Adaptation of mycobacteria to growth conditions: a theoretical analysis of changes in gene expression revealed by microarrays. PLoS One 2013; 8:e59883. [PMID: 23593152 PMCID: PMC3625197 DOI: 10.1371/journal.pone.0059883] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 02/19/2013] [Indexed: 11/19/2022] Open
Abstract
Background Microarray analysis is a powerful technique for investigating changes in gene expression. Currently, results (r-values) are interpreted empirically as either unchanged or up- or down-regulated. We now present a mathematical framework, which relates r-values to the macromolecular properties of population-average cells. The theory is illustrated by the analysis of published data for two species; namely, Mycobacterium bovis BCG Pasteur and Mycobacterium smegmatis mc2 155. Each species was grown in a chemostat at two different growth rates. Application of the theory reveals the growth rate dependent changes in the mycobacterial proteomes. Principal Findings The r-value r(i) of any ORF (ORF(i)) encoding protein p(i) was shown to be equal to the ratio of the concentrations of p(i) and so directly proportional to the ratio of the numbers of copies of p(i) per population-average cells of the two cultures. The proportionality constant can be obtained from the ratios DNA: RNA: protein. Several subgroups of ORFs were identified because they shared a particular r-value. Histograms of the number of ORFs versus the expression ratio were simulated by combining the particular r-values of several subgroups of ORFs. The largest subgroup was ORF(j) (r(j) = 1.00± SD) which was estimated to comprise respectively 59% and 49% of ORFs of M. bovis BCG Pasteur and M. smegmatis mc2 155. The standard deviations reflect the properties of the cDNA preparations investigated. Significance The analysis provided a quantitative view of growth rate dependent changes in the proteomes of the mycobacteria studied. The majority of the ORFs were found to be constitutively expressed. In contrast, the protein compositions of the outer permeability barriers and cytoplasmic membranes were found to be dependent on growth rate; thus illustrating the response of bacteria to their environment. The theoretical approach applies to any cultivatable bacterium under a wide range of growth conditions.
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Affiliation(s)
- Robert Ashley Cox
- Division of Mycobacterial Research, National Institute for Medical Research, London, United Kingdom.
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Brzostek A, Rumijowska-Galewicz A, Dziadek B, Wojcik EA, Dziadek J. ChoD and HsdD can be dispensable for cholesterol degradation in mycobacteria. J Steroid Biochem Mol Biol 2013; 134:1-7. [PMID: 23064392 DOI: 10.1016/j.jsbmb.2012.09.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 09/27/2012] [Accepted: 09/30/2012] [Indexed: 11/16/2022]
Abstract
Cholesterol degradation is achieved through a complex metabolic pathway that starts with the oxidation of the 17-alkyl side chain and the steroid ring system. In bacteria, the oxidation of the 3β-hydroxyl group and isomerization of the resulting cholest-5-en-3-one to cholest-4-en-3-one is catalyzed by hydroxysteroid dehydrogenase (HsdD) or cholesterol oxidase (ChoD). Genes encoding both enzymes were annotated in both fast and slow growing mycobacteria, however the enzymatic activity was confirmed for HsdD, exclusively. Here, we used homologous recombination to engineer multiple mutants, and directly show that both ChoD and HsdD are dispensable for cholesterol degradation in fast-growing Mycobacterium smegmatis mc(2)155 and slow-growing Mycobacterium tuberculosis H37Rv strains. The mutants deffective in the synthesis of ChoD, HsdD or both enzymes were able to grow in minimal media supplemented with cholesterol as a sole source of carbon and energy. Multiple mutants, defective in synthesis of ChoD, HsdD and ketosteroid dehydrogenase (KstD), showed attenuated growth in minimal medium supplemented with cholesterol and accumulated cholesterol degradation intermediates: androstendion (AD) and 9-hydroxy androstendion (9OHAD).
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Affiliation(s)
- Anna Brzostek
- Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
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43
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Li SK, Ng PKS, Qin H, Lau JKY, Lau JPY, Tsui SKW, Chan TF, Lau TCK. Identification of small RNAs in Mycobacterium smegmatis using heterologous Hfq. RNA 2013; 19:74-84. [PMID: 23169799 PMCID: PMC3527728 DOI: 10.1261/rna.034116.112] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 10/22/2012] [Indexed: 05/30/2023]
Abstract
Gene regulation by small RNAs (sRNAs) has been extensively studied in various bacteria. However, the presence and roles of sRNAs in mycobacteria remain largely unclear. Immunoprecipitation of RNA chaperone Hfq to enrich for sRNAs is one of the effective methods to isolate sRNAs. However, the lack of an identified mycobacterial hfq restricts the feasibility of this approach. We developed a novel method that takes advantage of the conserved inherent sRNAs-binding capability of heterologous Hfq from Escherichia coli to enrich sRNAs from Mycobacterium smegmatis, a model organism for studying Mycobacterium tuberculosis. We validated 12 trans-encoded and 12 cis-encoded novel sRNAs in M. smegmatis. Many of these sRNAs are differentially expressed at exponential phase compared with stationary phase, suggesting that sRNAs are involved in the growth of mycobacteria. Intriguingly, five of the cis-encoded novel sRNAs target known transposases. Phylogenetic conservation analysis shows that these sRNAs are pathogenicity dependent. We believe that our findings will serve as an important reference for future analysis of sRNAs regulation in mycobacteria and will contribute significantly to the development of sRNAs prediction programs. Moreover, this novel method of using heterologous Hfq for sRNAs enrichment can be of general use for the discovery of bacterial sRNAs in which no endogenous Hfq is identified.
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Affiliation(s)
- Sai-Kam Li
- Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR
| | | | - Hao Qin
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR
| | - Jeffrey Kwan-Yiu Lau
- Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR
| | | | | | - Ting-Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR
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Rana AK, Singh A, Gurcha SS, Cox LR, Bhatt A, Besra GS. Ppm1-encoded polyprenyl monophosphomannose synthase activity is essential for lipoglycan synthesis and survival in mycobacteria. PLoS One 2012; 7:e48211. [PMID: 23118955 PMCID: PMC3485146 DOI: 10.1371/journal.pone.0048211] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 09/26/2012] [Indexed: 02/03/2023] Open
Abstract
The biosynthesis of mycobacterial mannose-containing lipoglycans, such as lipomannan (LM) and the immunomodulator lipoarabinomanan (LAM), is carried out by the GT-C superfamily of glycosyltransferases that require polyprenylphosphate-based mannose (PPM) as a sugar donor. The essentiality of lipoglycan synthesis for growth makes the glycosyltransferase that synthesizes PPM, a potential drug target in Mycobacterium tuberculosis, the causative agent of tuberculosis. In M. tuberculosis, PPM has been shown to be synthesized by Ppm1 in enzymatic assays. However, genetic evidence for its essentiality and in vivo role in LM/LAM and PPM biosynthesis is lacking. In this study, we demonstrate that MSMEG3859, a Mycobacterium smegmatis gene encoding the homologue of the catalytic domain of M. tuberculosis Ppm1, is essential for survival. Depletion of MSMEG3859 in a conditional mutant of M. smegmatis resulted in the loss of higher order phosphatidyl-myo-inositol mannosides (PIMs) and lipomannan. We were also able to demonstrate that two other M. tuberculosis genes encoding glycosyltransferases that either had been shown to possess PPM synthase activity (Rv3779), or were involved in synthesizing similar polyprenol-linked donors (ppgS), were unable to compensate for the loss of MSMEG3859 in the conditional mutant.
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Affiliation(s)
- Amrita K. Rana
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Albel Singh
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Sudagar S. Gurcha
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Liam R. Cox
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (LRC); (AB); (GSB)
| | - Apoorva Bhatt
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (LRC); (AB); (GSB)
| | - Gurdyal S. Besra
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (LRC); (AB); (GSB)
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Kateete DP, Katabazi FA, Okeng A, Okee M, Musinguzi C, Asiimwe BB, Kyobe S, Asiimwe J, Boom WH, Joloba ML. Rhomboids of Mycobacteria: characterization using an aarA mutant of Providencia stuartii and gene deletion in Mycobacterium smegmatis. PLoS One 2012; 7:e45741. [PMID: 23029216 PMCID: PMC3448690 DOI: 10.1371/journal.pone.0045741] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 08/24/2012] [Indexed: 01/07/2023] Open
Abstract
Background Rhomboids are ubiquitous proteins with unknown roles in mycobacteria. However, bioinformatics suggested putative roles in DNA replication pathways and metabolite transport. Here, mycobacterial rhomboid-encoding genes were characterized; first, using the Providencia stuartii null-rhomboid mutant and then deleted from Mycobacterium smegmatis for additional insight in mycobacteria. Methodology/Principal Findings Using in silico analysis we identified in M. tuberculosis genome the genes encoding two putative rhomboid proteins; Rv0110 (referred to as “rhomboid protease 1”) and Rv1337 (“rhomboid protease 2”). Genes encoding orthologs of these proteins are widely represented in all mycobacterial species. When transformed into P. stuartii null-rhomboid mutant (ΔaarA), genes encoding mycobacterial orthologs of “rhomboid protease 2” fully restored AarA activity (AarA is the rhomboid protein of P. stuartii). However, most genes encoding mycobacterial “rhomboid protease 1” orthologs did not. Furthermore, upon gene deletion in M. smegmatis, the ΔMSMEG_4904 single mutant (which lost the gene encoding MSMEG_4904, orthologous to Rv1337, “rhomboid protease 2”) formed the least biofilms and was also more susceptible to ciprofloxacin and novobiocin, antimicrobials that inhibit DNA gyrase. However, the ΔMSMEG_5036 single mutant (which lost the gene encoding MSMEG_5036, orthologous to Rv0110, “rhomboid protease 1”) was not as susceptible. Surprisingly, the double rhomboid mutant ΔMSMEG_4904–ΔMSMEG_5036 (which lost genes encoding both homologs) was also not as susceptible suggesting compensatory effects following deletion of both rhomboid-encoding genes. Indeed, transforming the double mutant with a plasmid encoding MSMEG_5036 produced phenotypes of the ΔMSMEG_4904 single mutant (i.e. susceptibility to ciprofloxacin and novobiocin). Conclusions/Significance Mycobacterial rhomboid-encoding genes exhibit differences in complementing aarA whereby it's only genes encoding “rhomboid protease 2” orthologs that fully restore AarA activity. Additionally, gene deletion data suggests inhibition of DNA gyrase by MSMEG_4904; however, the ameliorated effect in the double mutant suggests occurrence of compensatory mechanisms following deletion of genes encoding both rhomboids.
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Affiliation(s)
- David Patrick Kateete
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
| | - Fred Ashaba Katabazi
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
| | - Alfred Okeng
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
| | - Moses Okee
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
| | - Conrad Musinguzi
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
| | - Benon Byamugisha Asiimwe
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
| | - Samuel Kyobe
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
| | - Jeniffer Asiimwe
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
- College of Veterinary Medicine, Animal Resources and Biosecurity (CoVAB), Makerere University, Kampala, Uganda
| | - W. Henry Boom
- Tuberculosis Research Unit (TBRU), Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Moses Lutaakome Joloba
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences (MakCHS), Kampala, Uganda
- Tuberculosis Research Unit (TBRU), Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
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46
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Joyce G, Williams KJ, Robb M, Noens E, Tizzano B, Shahrezaei V, Robertson BD. Cell division site placement and asymmetric growth in mycobacteria. PLoS One 2012; 7:e44582. [PMID: 22970255 PMCID: PMC3438161 DOI: 10.1371/journal.pone.0044582] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 08/08/2012] [Indexed: 01/12/2023] Open
Abstract
Mycobacteria are members of the actinomycetes that grow by tip extension and lack apparent homologues of the known cell division regulators found in other rod-shaped bacteria. Previous work using static microscopy on dividing mycobacteria led to the hypothesis that these cells can grow and divide asymmetrically, and at a wide range of sizes, in contrast to the cell growth and division patterns observed in the model rod-shaped organisms. In this study, we test this hypothesis using live-cell time-lapse imaging of dividing Mycobacterium smegmatis labelled with fluorescent PBP1a, to probe peptidoglycan synthesis and label the cell septum. We demonstrate that the new septum is placed accurately at mid-cell, and that the asymmetric division observed is a result of differential growth from the cell tips, with a more than 2-fold difference in growth rate between fast and slow growing poles. We also show that the division site is not selected at a characteristic cell length, suggesting this is not an important cue during the mycobacterial cell cycle.
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Affiliation(s)
- Graham Joyce
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College, London, United Kingdom
| | - Kerstin J. Williams
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College, London, United Kingdom
| | - Matthew Robb
- Department of Mathematics, Imperial College, London, United Kingdom
| | - Elke Noens
- European Molecular Biology Laboratory, Hamburg, Germany
| | | | - Vahid Shahrezaei
- Department of Mathematics, Imperial College, London, United Kingdom
| | - Brian D. Robertson
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College, London, United Kingdom
- * E-mail:
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47
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Chen JM, Uplekar S, Gordon SV, Cole ST. A point mutation in cycA partially contributes to the D-cycloserine resistance trait of Mycobacterium bovis BCG vaccine strains. PLoS One 2012; 7:e43467. [PMID: 22912881 PMCID: PMC3422274 DOI: 10.1371/journal.pone.0043467] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 07/20/2012] [Indexed: 11/18/2022] Open
Abstract
In mycobacteria, CycA a D-serine, L- and D-alanine, and glycine transporter also functions in the uptake of D-cycloserine, an important second-line anti-tubercular drug. A single nucleotide polymorphism identified in the cycA gene of BCG was hypothesized to contribute to the increased resistance of Mycobacterium bovis bacillus Calmette-Guérin (BCG) to D-cycloserine compared to wild-type Mycobacterium tuberculosis or Mycobacterium bovis. Working along these lines, a merodiploid strain of BCG expressing Mycobacterium tuberculosis CycA was generated and found to exhibit increased susceptibility to D-cycloserine albeit not to the same extent as wild-type Mycobacterium tuberculosis or Mycobacterium bovis. In addition, recombinant Mycobacterium smegmatis strains expressing either Mycobacterium tuberculosis or Mycobacterium bovis CycA but not BCG CycA were rendered more susceptible to D-cycloserine. These findings support the notion that CycA-mediated uptake in BCG is impaired as a result of a single nucleotide polymorphism; however, the partial contribution of this impairment to D-cycloserine resistance suggests the involvement of additional genetic lesions in this phenotype.
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Affiliation(s)
- Jeffrey M Chen
- École Polytechnique Fédérale de Lausanne, Global Health Institute, Lausanne, Switzerland.
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48
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Abstract
During Mycobacterium tuberculosis infection, a population of bacteria likely becomes refractory to antibiotic killing in the absence of genotypic resistance, making treatment challenging. We describe an in vitro model capable of yielding a phenotypically antibiotic-tolerant subpopulation of cells, often called persisters, within populations of Mycobacterium smegmatis and M. tuberculosis. We find that persisters are distinct from the larger antibiotic-susceptible population, as a small drop in dissolved oxygen (DO) saturation (20%) allows for their survival in the face of bactericidal antibiotics. In contrast, if high levels of DO are maintained, all cells succumb, sterilizing the culture. With increasing evidence that bactericidal antibiotics induce cell death through the production of reactive oxygen species (ROS), we hypothesized that the drop in DO decreases the concentration of ROS, thereby facilitating persister survival, and maintenance of high DO yields sufficient ROS to kill persisters. Consistent with this hypothesis, the hydroxyl-radical scavenger thiourea, when added to M. smegmatis cultures maintained at high DO levels, rescues the persister population. Conversely, the antibiotic clofazimine, which increases ROS via an NADH-dependent redox cycling pathway, successfully eradicates the persister population. Recent work suggests that environmentally induced antibiotic tolerance of bulk populations may result from enhanced antioxidant capabilities. We now show that the small persister subpopulation within a larger antibiotic-susceptible population also shows differential susceptibility to antibiotic-induced hydroxyl radicals. Furthermore, we show that stimulating ROS production can eradicate persisters, thus providing a potential strategy to managing persistent infections.
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Affiliation(s)
- Sarah Schmidt Grant
- Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA 02114
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114
| | - Benjamin B. Kaufmann
- Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Nikhilesh S. Chand
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138; and
| | - Nathan Haseley
- Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
- Harvard–MIT Division of Health Sciences and Technology, Cambridge, MA 02139
| | - Deborah T. Hung
- Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA 02114
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
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49
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Trauner A, Lougheed KEA, Bennett MH, Hingley-Wilson SM, Williams HD. The dormancy regulator DosR controls ribosome stability in hypoxic mycobacteria. J Biol Chem 2012; 287:24053-63. [PMID: 22544737 PMCID: PMC3390679 DOI: 10.1074/jbc.m112.364851] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 04/27/2012] [Indexed: 01/01/2023] Open
Abstract
It is thought that during latent infection, Mycobacterium tuberculosis bacilli are retained within granulomas in a low-oxygen environment. The dormancy survival (Dos) regulon, regulated by the response regulator DosR, appears to be essential for hypoxic survival in M. tuberculosis, but it is not known how the regulon promotes survival. Here we report that mycobacteria, in contrast to enteric bacteria, do not form higher-order structures (e.g. ribosomal dimers) upon entry into stasis. Instead, ribosomes are stabilized in the associated form (70S). Using a strategy incorporating microfluidic, proteomic, and ribosomal profiling techniques to elucidate the fate of mycobacterial ribosomes during hypoxic stasis, we show that the dormancy regulator DosR is required for optimal ribosome stabilization. We present evidence that the majority of this effect is mediated by the DosR-regulated protein MSMEG_3935 (a S30AE domain protein), which is associated with the ribosome under hypoxic conditions. A Δ3935 mutant phenocopies the ΔdosR mutant during hypoxia, and complementation of ΔdosR with the MSMEG_3935 gene leads to complete recovery of dosR mutant phenotypes during hypoxia. We suggest that this protein is named ribosome-associated factor under hypoxia (RafH) and that it is the major factor responsible for DosR-mediated hypoxic survival in mycobacteria.
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Affiliation(s)
- Andrej Trauner
- From the Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Kathryn E. A. Lougheed
- From the Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Mark H. Bennett
- From the Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Suzanne M. Hingley-Wilson
- From the Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Huw D. Williams
- From the Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
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50
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Polishchuk LV, Bambura OI, Luk'ianchuk VV. [Bacteriocidal activity of Streptomyces cultures]. Mikrobiol Z 2012; 74:45-51. [PMID: 23088099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bacteriocidal activity of metabolites synthesized by 17 plasmid-containing cultures of Streptomyces has been studied. These cultures were isolated from soils of Ukraine with different anthropogenic contamination. The cultures, in their majority (85.3%), synthesized bioactive metabolites, which suppressed growth of microorganisms of different taxonomical groups, pathogenic for people, animals or plants. None of 17 Streptomyces cultures was able to suppress growth of yeasts or Escherichia coli. All 17 investigated cultures of Streptomyces were polyresistant to antibiotics, which were used in medicine and veterinary: makrolide, aminoglycoside, beta-lactam and other groups. Resistance of 8 cultures to the antibiotic thiostrepton, which was widely used in some branches of science, was found.
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