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Niu M, Sui Z, Jiang G, Wang L, Yao X, Hu Y. The Mutation of the DNA-Binding Domain of Fur Protein Enhances the Pathogenicity of Edwardsiella piscicida via Inducing Overpowering Pyroptosis. Microorganisms 2023; 12:11. [PMID: 38276180 PMCID: PMC10821184 DOI: 10.3390/microorganisms12010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/30/2023] [Accepted: 12/12/2023] [Indexed: 01/27/2024] Open
Abstract
Edwardsiella piscicida is an important fish pathogen with a broad host that causes substantial economic losses in the aquaculture industry. Ferric uptake regulator (Fur) is a global transcriptional regulator and contains two typical domains, the DNA-binding domain and dimerization domain. In a previous study, we obtained a mutant strain of full-length fur of E. piscicida, TX01Δfur, which displayed increased siderophore production and stress resistance factors and decreased pathogenicity. To further reveal the regulatory mechanism of Fur, the DNA-binding domain (N-terminal) of Fur was knocked out in this study and the mutant was named TX01Δfur2. We found that TX01Δfur2 displayed increased siderophore production and enhanced adversity tolerance, including a low pH, manganese, and high temperature stress, which was consistent with the phenotype of TX01Δfur. Contrary to TX01Δfur, whose virulence was weakened, TX01Δfur2 displayed an ascended invasion of nonphagocytic cells and enhanced destruction of phagocytes via inducing overpowering or uncontrollable pyroptosis, which was confirmed by the fact that TX01Δfur2 induced higher levels of cytotoxicity, IL-1β, and p10 in macrophages than TX01. More importantly, TX01Δfur2 displayed an increased global virulence to the host, which was confirmed by the result that TX01Δfur2 caused higher lethality outcomes for healthy tilapias than TX01. These results demonstrate that the mutation of the Fur N-terminal domain augments the resistance level against the stress and pathogenicity of E. piscicida, which is not dependent on the bacterial number in host cells or host tissues, although the capabilities of biofilm formation and the motility of TX01Δfur2 decline. These interesting findings provide a new insight into the functional analysis of Fur concerning the regulation of virulence in E. piscicida and prompt us to explore the subtle regulation mechanism of Fur in the future.
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Affiliation(s)
- Mimi Niu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China;
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (G.J.); (L.W.)
- Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou 571101, China
- School of Life Sciences, Hainan University, Haikou 570228, China
| | - Zhihai Sui
- School of Life Science, Linyi University, Linyi 276000, China;
| | - Guoquan Jiang
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (G.J.); (L.W.)
- Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou 571101, China
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Ling Wang
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (G.J.); (L.W.)
- Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou 571101, China
- Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-Resources, Haikou 571101, China
| | - Xuemei Yao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China;
- School of Marine Biology and Aquaculture, Hainan University, Haikou 570228, China
| | - Yonghua Hu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (G.J.); (L.W.)
- Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou 571101, China
- Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-Resources, Haikou 571101, China
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2
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Fan X, Zhao B, Zhang W, Li N, Mi K, Wang B. Coevolution of furA-Regulated Hyper-Inflammation and Mycobacterial Resistance to Oxidative Killing through Adaptation to Hydrogen Peroxide. Microbiol Spectr 2023; 11:e0536722. [PMID: 37358434 PMCID: PMC10433983 DOI: 10.1128/spectrum.05367-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 05/25/2023] [Indexed: 06/27/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is highly resistant to host oxidative killing. We hypothesized that the evolutionary adaptation of M. smegmatis to hydrogen peroxide (H2O2) would endow the nonpathogenic Mycobacterium persistent in a host. In the study, we screened a highly H2O2-resistant strain (mc2114) via evolutionary H2O2 adaptation in vitro. The MIC of mc2114 to H2O2 is 320 times that of wild-type mc2155. Mouse infection experiments showed that mc2114, similar to Mtb, was persistent in the lungs and caused high lethality in mice with restricted responses of NOX2, ROS, IFN-γ, decreased macrophage apoptosis, and overexpressed inflammatory cytokines in the lungs. Whole-genome sequencing analysis revealed that mc2114 harbored 29 single nucleotide polymorphisms in multiple genes; one of them was on the furA gene that caused FurA deficiency-mediated overexpression of KatG, a catalase-peroxidase to detoxify ROS. Complementation of mc2114 with a wild-type furA gene reversed lethality and hyper-inflammatory response in mice with rescued overexpression of KatG and inflammatory cytokines, whereas NOX2, ROS, IFN-γ, and macrophage apoptosis remained reduced. The results indicate that although FurA regulates KatG expression, it does not contribute significantly to the restriction of ROS response. Instead, FurA deficiency is responsible for the detrimental pulmonary inflammation that contributes to the severity of the infection, a previously nonrecognized function of FurA in mycobacterial pathogenesis. The study also indicates that mycobacterial resistance to oxidative burst results from complex mechanisms involving adaptive genetic changes in multiple genes. IMPORTANCE Mycobacterium tuberculosis (Mtb) causes human tuberculosis (TB), which has killed more people in human history than any other microorganism. However, the mechanisms underlying Mtb pathogenesis and related genes have not yet been fully elucidated, which impedes the development of effective strategies for containing and eradicating TB. In the study, we generated a mutant of M. smegmatis (mc2114) with multiple mutations by an adaptive evolutionary screen with H2O2. One of the mutations in furA caused a deficiency of FurA, which mediated severe inflammatory lung injury and higher lethality in mice by overexpression of inflammatory cytokines. Our results indicate that FurA-regulated pulmonary inflammation plays a critical role in mycobacterial pathogenesis in addition to the known downregulation of NOX2, ROS, IFN-γ responses, and macrophage apoptosis. Further analysis of the mutations in mc2114 would identify more genes related to the increased pathogenicity and help in devising new strategies for containing and eradicating TB.
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Affiliation(s)
- Xin Fan
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Bei Zhao
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Weishan Zhang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Ning Li
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Kaixia Mi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Beinan Wang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
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3
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Pacifico R, Del Gaudio N, Bove G, Altucci L, Siragusa L, Cruciani G, Ruvo M, Bellavita R, Grieco P, Adamo MFA. Discovery of a new class of triazole based inhibitors of acetyl transferase KAT2A. J Enzyme Inhib Med Chem 2022; 37:1987-1994. [PMID: 35880250 PMCID: PMC9331200 DOI: 10.1080/14756366.2022.2097447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
We have recently developed a new synthetic methodology that provided both N-aryl-5-hydroxytriazoles and N-pyridine-4-alkyl triazoles. A selection of these products was carried through virtual screening towards targets that are contemporary and validated for drug discovery and development. This study determined a number of potential structure target dyads of which N-pyridinium-4-carboxylic-5-alkyl triazole displayed the highest score specificity towards KAT2A. Binding affinity tests of abovementioned triazole and related analogs towards KAT2A confirmed the predictions of the in-silico assay. Finally, we have run in vitro inhibition assays of selected triazoles towards KAT2A; the ensemble of binding and inhibition assays delivered pyridyl-triazoles carboxylates as the prototype of a new class of inhibitors of KAT2A.
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Affiliation(s)
- Roberta Pacifico
- Centre for Synthesis and Chemical Biology (CSCB), Department of Chemistry, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Nunzio Del Gaudio
- Department of precision medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Guglielmo Bove
- Department of precision medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Lucia Altucci
- Department of precision medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | | | - Gabriele Cruciani
- Laboratory for Chemometrics and Molecular Modeling, Department of Chemistry, Biology, and Biotechnology, University of Perugia, Perugia, Italy
| | - Menotti Ruvo
- Institute of Biostructures and Bioimaging, Consiglio Nazionale delle Ricerche, Naples, Italy
| | - Rosa Bellavita
- Department of Pharmacy, School of Medicine, University of Naples 'Federico II', Naples, Italy
| | - Paolo Grieco
- Department of Pharmacy, School of Medicine, University of Naples 'Federico II', Naples, Italy
| | - Mauro F A Adamo
- Centre for Synthesis and Chemical Biology (CSCB), Department of Chemistry, Royal College of Surgeons in Ireland, Dublin, Ireland
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4
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Jiang Z, Zhuang Z, Mi K. Experimental Evolution Reveals Redox State Modulates Mycobacterial Pathogenicity. Front Genet 2022; 13:758304. [PMID: 35368697 PMCID: PMC8965865 DOI: 10.3389/fgene.2022.758304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 02/10/2022] [Indexed: 11/19/2022] Open
Abstract
Understanding how Mycobacterium tuberculosis has evolved into a professional pathogen is helpful in studying its pathogenesis and for designing vaccines. We investigated how the evolutionary adaptation of M. smegmatis mc251 to an important clinical stressor H2O2 allows bacteria to undergo coordinated genetic mutations, resulting in increased pathogenicity. Whole-genome sequencing identified a mutation site in the fur gene, which caused increased expression of katG. Using a Wayne dormancy model, mc251 showed a growth advantage over its parental strain mc2155 in recovering from dormancy under anaerobic conditions. Meanwhile, the high level of KatG in mc251 was accompanied by a low level of ATP, which meant that mc251 is at a low respiratory level. Additionally, the redox-related protein Rv1996 showed different phenotypes in different specific redox states in M. smegmatis mc2155 and mc251, M. bovis BCG, and M. tuberculosis mc27000. In conclusion, our study shows that the same gene presents different phenotypes under different physiological conditions. This may partly explain why M. smegmatis and M. tuberculosis have similar virulence factors and signaling transduction systems such as two-component systems and sigma factors, but due to the different redox states in the corresponding bacteria, M. smegmatis is a nonpathogen, while M. tuberculosis is a pathogen. As mc251 overcomes its shortcomings of rapid removal, it can potentially be developed as a vaccine vector.
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Affiliation(s)
- Zheng Jiang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Zengfang Zhuang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Kaixia Mi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Kaixia Mi,
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5
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Modak B, Girkar S, Narayan R, Kapoor S. Mycobacterial Membranes as Actionable Targets for Lipid-Centric Therapy in Tuberculosis. J Med Chem 2022; 65:3046-3065. [PMID: 35133820 DOI: 10.1021/acs.jmedchem.1c01870] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Infectious diseases remain significant health concerns worldwide, and resistance is particularly common in patients with tuberculosis caused by Mycobacterium tuberculosis. The development of anti-infectives with novel modes of action may help overcome resistance. In this regard, membrane-active agents, which modulate membrane components essential for the survival of pathogens, present attractive antimicrobial agents. Key advantages of membrane-active compounds include their ability to target slow-growing or dormant bacteria and their favorable pharmacokinetics. Here, we comprehensively review recent advances in the development of membrane-active chemotypes that target mycobacterial membranes and discuss clinically relevant membrane-active antibacterial agents that have shown promise in counteracting bacterial infections. We discuss the relationship between the membrane properties and the synthetic requirements within the chemical scaffold, as well as the limitations of current membrane-active chemotypes. This review will lay the chemical groundwork for the development of membrane-active antituberculosis agents and will foster the discovery of more effective antitubercular agents.
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Affiliation(s)
- Biswabrata Modak
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Siddhali Girkar
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Goa 403110, India
| | - Rishikesh Narayan
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Goa 403110, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India.,Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8528, Japan
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6
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Fridianto KT, Li M, Hards K, Negatu DA, Cook GM, Dick T, Lam Y, Go ML. Functionalized Dioxonaphthoimidazoliums: A Redox Cycling Chemotype with Potent Bactericidal Activities against Mycobacterium tuberculosis. J Med Chem 2021; 64:15991-16007. [PMID: 34706190 DOI: 10.1021/acs.jmedchem.1c01383] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Disruption of redox homeostasis in mycobacteria causes irreversible stress induction and cell death. Here, we report the dioxonaphthoimidazolium scaffold as a novel redox cycling antituberculosis chemotype with potent bactericidal activity against growing and nutrient-starved phenotypically drug-resistant nongrowing bacteria. Maximal potency was dependent on the activation of the redox cycling quinone by the positively charged scaffold and accessibility to the mycobacterial cell membrane as directed by the lipophilicity and conformational characteristics of the N-substituted side chains. Evidence from microbiological, biochemical, and genetic investigations implicates a redox-driven mode of action that is reliant on the reduction of the quinone by type II NADH dehydrogenase (NDH2) for the generation of bactericidal levels of the reactive oxygen species (ROS). The bactericidal profile of a potent water-soluble analogue 32 revealed good activity against nutrient-starved organisms in the Loebel model of dormancy, low spontaneous resistance mutation frequency, and synergy with isoniazid in the checkerboard assay.
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Affiliation(s)
| | | | - Kiel Hards
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Dereje A Negatu
- Center for Discovery and Innovation, Hackensack Meridian Health & Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, New Jersey 07110, United States
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Thomas Dick
- Center for Discovery and Innovation, Hackensack Meridian Health & Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, New Jersey 07110, United States.,Department of Microbiology and Immunology, Georgetown University, Washington, District of Columbia 20057, United States
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7
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Ling Y, Hao ZY, Liang D, Zhang CL, Liu YF, Wang Y. The Expanding Role of Pyridine and Dihydropyridine Scaffolds in Drug Design. Drug Des Devel Ther 2021; 15:4289-4338. [PMID: 34675489 PMCID: PMC8520849 DOI: 10.2147/dddt.s329547] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/21/2021] [Indexed: 12/13/2022] Open
Abstract
Pyridine-based ring systems are one of the most extensively used heterocycles in the field of drug design, primarily due to their profound effect on pharmacological activity, which has led to the discovery of numerous broad-spectrum therapeutic agents. In the US FDA database, there are 95 approved pharmaceuticals that stem from pyridine or dihydropyridine, including isoniazid and ethionamide (tuberculosis), delavirdine (HIV/AIDS), abiraterone acetate (prostate cancer), tacrine (Alzheimer's), ciclopirox (ringworm and athlete's foot), crizotinib (cancer), nifedipine (Raynaud's syndrome and premature birth), piroxicam (NSAID for arthritis), nilvadipine (hypertension), roflumilast (COPD), pyridostigmine (myasthenia gravis), and many more. Their remarkable therapeutic applications have encouraged researchers to prepare a larger number of biologically active compounds decorated with pyridine or dihydropyridine, expandeing the scope of finding a cure for other ailments. It is thus anticipated that myriad new pharmaceuticals containing the two heterocycles will be available in the forthcoming decade. This review examines the prospects of highly potent bioactive molecules to emphasize the advantages of using pyridine and dihydropyridine in drug design. We cover the most recent developments from 2010 to date, highlighting the ever-expanding role of both scaffolds in the field of medicinal chemistry and drug development.
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Affiliation(s)
- Yong Ling
- Department of Pharmacy, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, People’s Republic of China
| | - Zhi-You Hao
- School of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, Henan, People’s Republic of China
| | - Dong Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, Guangxi, People’s Republic of China
| | - Chun-Lei Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, People’s Republic of China
| | - Yan-Fei Liu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China
| | - Yan Wang
- HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, People’s Republic of China
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8
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Le Hang NT, Hijikata M, Maeda S, Miyabayashi A, Wakabayashi K, Seto S, Diem NTK, Yen NTT, Van Duc L, Thuong PH, Van Huan H, Hoang NP, Mitarai S, Keicho N, Kato S. Phenotypic and genotypic features of the Mycobacterium tuberculosis lineage 1 subgroup in central Vietnam. Sci Rep 2021; 11:13609. [PMID: 34193941 PMCID: PMC8245516 DOI: 10.1038/s41598-021-92984-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 06/15/2021] [Indexed: 11/09/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) has different features depending on different geographic areas. We collected Mtb strains from patients with smear-positive pulmonary tuberculosis in Da Nang, central Vietnam. Using a whole genome sequencing platform, including genome assembly complemented by long-read-sequencing data, genomic characteristics were studied. Of 181 Mtb isolates, predominant Vietnamese EAI4_VNM and EAI4-like spoligotypes (31.5%), ZERO strains (5.0%), and part of EAI5 (11.1%) were included in a lineage-1 (L1) sublineage, i.e., L1.1.1.1. These strains were found less often in younger people, and they genetically clustered less frequently than other modern strains. Patients infected with ZERO strains demonstrated less lung infiltration. A region in RD2bcg spanning six loci, i.e., PE_PGRS35, cfp21, Rv1985c, Rv1986, Rv1987, and erm(37), was deleted in EAI4_VNM, EAI4-like, and ZERO strains, whereas another 118 bp deletion in furA was specific only to ZERO strains. L1.1.1.1-sublineage-specific deletions in PE_PGRS4 and PE_PGRS22 were also identified. RD900, seen in ancestral lineages, was present in majority of the L1 members. All strains without IS6110 (5.0%) had the ZERO spoligo-pattern. Distinctive features of the ancestral L1 strains provide a basis for investigation of the modern versus ancestral Mtb lineages and allow consideration of countermeasures against this heterogeneous pathogen.
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Affiliation(s)
| | - Minako Hijikata
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, JATA, Tokyo, Japan
| | - Shinji Maeda
- Faculty of Pharmaceutical Sciences, Hokkaido University of Science, Hokkaido, Japan
| | - Akiko Miyabayashi
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, JATA, Tokyo, Japan
| | - Keiko Wakabayashi
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, JATA, Tokyo, Japan
| | - Shintaro Seto
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, JATA, Tokyo, Japan
| | | | | | - Le Van Duc
- Da Nang General Hospital, Da Nang, Vietnam
| | | | | | | | - Satoshi Mitarai
- Department of Mycobacterium Reference and Research, The Research Institute of Tuberculosis, JATA, Tokyo, Japan
| | - Naoto Keicho
- The Research Institute of Tuberculosis, JATA, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo, 204-8533, Japan. .,National Center for Global Health and Medicine, Tokyo, Japan.
| | - Seiya Kato
- The Research Institute of Tuberculosis, JATA, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo, 204-8533, Japan
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9
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Dow A, Sule P, O’Donnell TJ, Burger A, Mattila JT, Antonio B, Vergara K, Marcantonio E, Adams LG, James N, Williams PG, Cirillo JD, Prisic S. Zinc limitation triggers anticipatory adaptations in Mycobacterium tuberculosis. PLoS Pathog 2021; 17:e1009570. [PMID: 33989345 PMCID: PMC8121289 DOI: 10.1371/journal.ppat.1009570] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/19/2021] [Indexed: 01/06/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) has complex and dynamic interactions with the human host, and subpopulations of Mtb that emerge during infection can influence disease outcomes. This study implicates zinc ion (Zn2+) availability as a likely driver of bacterial phenotypic heterogeneity in vivo. Zn2+ sequestration is part of "nutritional immunity", where the immune system limits micronutrients to control pathogen growth, but this defense mechanism seems to be ineffective in controlling Mtb infection. Nonetheless, Zn2+-limitation is an environmental cue sensed by Mtb, as calprotectin triggers the zinc uptake regulator (Zur) regulon response in vitro and co-localizes with Zn2+-limited Mtb in vivo. Prolonged Zn2+ limitation leads to numerous physiological changes in vitro, including differential expression of certain antigens, alterations in lipid metabolism and distinct cell surface morphology. Furthermore, Mtb enduring limited Zn2+ employ defensive measures to fight oxidative stress, by increasing expression of proteins involved in DNA repair and antioxidant activity, including well described virulence factors KatG and AhpC, along with altered utilization of redox cofactors. Here, we propose a model in which prolonged Zn2+ limitation defines a population of Mtb with anticipatory adaptations against impending immune attack, based on the evidence that Zn2+-limited Mtb are more resistant to oxidative stress and exhibit increased survival and induce more severe pulmonary granulomas in mice. Considering that extracellular Mtb may transit through the Zn2+-limited caseum before infecting naïve immune cells or upon host-to-host transmission, the resulting phenotypic heterogeneity driven by varied Zn2+ availability likely plays a key role during early interactions with host cells.
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Affiliation(s)
- Allexa Dow
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Preeti Sule
- Microbial Pathogenesis and Immunology, Texas A&M University Health, Bryan, Texas, United States of America
| | - Timothy J. O’Donnell
- Department of Chemistry, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Andrew Burger
- School of Ocean and Earth Science and Technology, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Joshua T. Mattila
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Brandi Antonio
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Kevin Vergara
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Endrei Marcantonio
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - L. Garry Adams
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Nicholas James
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, Honolulu, Hawaii, United States of America
| | - Philip G. Williams
- Department of Chemistry, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Jeffrey D. Cirillo
- Microbial Pathogenesis and Immunology, Texas A&M University Health, Bryan, Texas, United States of America
| | - Sladjana Prisic
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
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10
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Florou Z, Mavroidi A, Vatidis G, Daniil Z, Gourgoulianis K, Petinaki E. Molecular Basis of Resistance to First-Line Drugs of Mycobacterium tuberculosis/canettii Strains in Greece. Microb Drug Resist 2021; 27:1389-1396. [PMID: 33877884 DOI: 10.1089/mdr.2020.0396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The aim of this study was to determine the rate and the mutations of genes involved to the first-line antituberculous drugs' resistance of M. tuberculosis/canettii isolated in Central Greece from 2010 to 2019. During the study period, the rate of resistance to isoniazid, rifampicin, ethambutol, and pyrazinamide was 5.4%, 0.4%, 1.1%, and 1.1%, respectively. All phenotypically resistant isolates (14 to isoniazid, 3 to ethambutol, 3 to pyrazinamide, and 1 to rifampicin) and 17 susceptible isolates (control group) were tested for the presence of mutations/alterations/polymorphisms by PCR followed by sequencing analysis. The molecular typing of isolates was based on multispacer sequence typing. Despite the phenotypic resistance, mutations were detected in 13 of 21 isolates (11 isoniazid resistant, 1 rifampicin, and 1 pyrazinamide resistant). Four isoniazid-resistant strains carried the most common mutations S315T and C-15T, whereas the remaining seven isolates carried either less known (E399, A162, W477STOP, S94A, G-48A, C-54T, C-17T, L203, A196, S124, and K367) or novel (D74N, G691S, Ains-85, and D171G); none of the susceptible strains was found to be positive for any novel mutation. The two single rifampicin- and pyrazinamide-resistant strains carried the known mutations S450L (also referred as S531L) and L182W, respectively. The presence of uncommon or novel mutations conferring resistance to isoniazid (INH) creates a diagnostic problem in the routine microbiological laboratory, since commercial methods are focused on the detection of the most common mechanisms of resistance (S315T, C-15T, A-16G, T-8C, and T-8A), therefore, fail to detect such strains. The regional differences in the frequencies of mutations associated with resistance to the first-line drugs provide hints for the development of better molecular-based diagnostic tests.
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Affiliation(s)
- Zoi Florou
- Department of Microbiology, University Hospital of Larissa, Larissa, Greece
| | - Aggeliki Mavroidi
- Department of Microbiology, Konstantopouleio-Patission, General Hospital of N. Ionias, Athens, Greece
| | - George Vatidis
- Department of Microbiology, University Hospital of Larissa, Larissa, Greece
| | - Zoi Daniil
- Department of Respiratory Medicine, Faculty of Medicine, University of Thessaly, Biopolis, Larissa, Greece
| | - Konstantinos Gourgoulianis
- Department of Respiratory Medicine, Faculty of Medicine, University of Thessaly, Biopolis, Larissa, Greece
| | - Efi Petinaki
- Department of Microbiology, University Hospital of Larissa, Larissa, Greece
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11
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Adams LB. Susceptibility and resistance in leprosy: Studies in the mouse model. Immunol Rev 2021; 301:157-174. [PMID: 33660297 PMCID: PMC8252540 DOI: 10.1111/imr.12960] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 12/24/2022]
Abstract
Leprosy is a chronic granulomatous infectious disease caused by the pathogen, Mycobacterium leprae, and the more recently discovered, M. lepromatosis. Described in 1873, M. leprae was among the first microorganisms to be proposed as a cause of a human infectious disease. As an obligate intracellular bacterium, it has still not thus far been reproducibly cultivated in axenic medium or cell cultures. Shepard's mouse footpad assay, therefore, was truly a breakthrough in leprosy research. The generation of immunosuppressed and genetically engineered mice, along with advances in molecular and cellular techniques, has since offered more tools for the study of the M. leprae–induced granuloma. While far from perfect, these new mouse models have provided insights into the immunoregulatory mechanisms responsible for the spectrum of this complex disease.
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Affiliation(s)
- Linda B Adams
- Department of Health and Human Services, Health Resources and Services Administration, Healthcare Systems Bureau, National Hansen's Disease Programs Laboratory Research Branch, Baton Rouge, LA, USA
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12
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Transcriptional regulator-induced phenotype screen reveals drug potentiators in Mycobacterium tuberculosis. Nat Microbiol 2020; 6:44-50. [PMID: 33199862 PMCID: PMC8331221 DOI: 10.1038/s41564-020-00810-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 10/05/2020] [Indexed: 02/07/2023]
Abstract
Transposon-based strategies provide a powerful and unbiased way to study bacterial stress response1–8, but these approaches cannot fully capture the complexities of network-based behavior. Here, we present a network-based genetic screening approach: the Transcriptional Regulator Induced Phenotype (TRIP) screen, which we used to identify previously uncharacterized network adaptations of Mycobacterium tuberculosis (Mtb) to the first-line anti-TB drug isoniazid (INH). We found regulators that alter INH susceptibility when induced, several of which could not be identified by standard gene disruption approaches. We then focused on a specific regulator, mce3R, which potentiated INH activity when induced. We compared mce3R-regulated genes with baseline INH transcriptional responses and implicated the gene ctpD (Rv1469) as a putative INH effector. Evaluating a ctpD disruption mutant demonstrated a previously unknown role for this gene in INH susceptibility. Integrating TRIP screening with network information can uncover sophisticated molecular response programs.
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13
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AlMatar M, Var I, Kayar B, Köksal F. Differential Expression of Resistant and Efflux Pump Genes in MDR-TB Isolates. Endocr Metab Immune Disord Drug Targets 2020; 20:271-287. [DOI: 10.2174/1871530319666191009153834] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/21/2019] [Accepted: 07/22/2019] [Indexed: 12/20/2022]
Abstract
Background:Numerous investigations demonstrate efflux as a worldwide bacterial mode of action which contributes to the resistance of drugs. The activity of antibiotics, which subjects to efflux, can be improved by the combined usage of efflux inhibitors. However, the efflux role to the overall levels of antibiotic resistance of clinical M. tuberculosis isolates is inadequately comprehended and is still disregarded by many.Method:Here, we assessed the contribution of resistant genes associated with isoniazid (INH) and rifampin (R) resistance to the levels of drug resistance in the (27) clinical isolates of MDR-TB. Additionally, the role of the resistance for six putative drug efflux pump genes to the antibiotics was investigated. The level of katG expression was down-regulated in 24/27 (88.88%) of MDR-TB isolates. Of the 27 MDR-TB isolates, inhA, oxyR-ahpC, and rpoB showed either overexpression or up-regulation in 8 (29.62%), 4 (14.81 %), and 24 (88.88%), respectively. Moreover, the efflux pump genes drrA, drrB, efpA, Rv2459, Rv1634, and Rv1250 were overexpressed under INH/RIF plus fresh pomegranate juice (FPJ) stress signifying the efflux pumps contribution to the overall levels of the resistance of MDR-TB isolates.Conclusion:These results displayed that the levels of drug resistance of MDR-TB clinical isolates are due to combination among drug efflux pump and the presence of mutations in target genes, a truth which is often ignored by the specialists of tuberculosis in favour of the almost undoubted significance of drug target- gene mutations for the resistance in M. tuberculosis.
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Affiliation(s)
- Manaf AlMatar
- Department of Biotechnology, Institute of Natural and Applied Sciences (Fen Bilimleri Enstitusu), Cukurova University, Adana, Turkey
| | - Işıl Var
- Department of Food Engineering, Agricultural Faculty, Cukurova University, Adana, Turkey
| | - Begüm Kayar
- Department of Medical Microbiology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Fatih Köksal
- Department of Medical Microbiology, Faculty of Medicine, Cukurova University, Adana, Turkey
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Dulberger CL, Rubin EJ, Boutte CC. The mycobacterial cell envelope - a moving target. Nat Rev Microbiol 2019; 18:47-59. [PMID: 31728063 DOI: 10.1038/s41579-019-0273-7] [Citation(s) in RCA: 163] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 01/12/2023]
Abstract
Mycobacterium tuberculosis, the leading cause of death due to infection, has a dynamic and immunomodulatory cell envelope. The cell envelope structurally and functionally varies across the length of the cell and during the infection process. This variability allows the bacterium to manipulate the human immune system, tolerate antibiotic treatment and adapt to the variable host environment. Much of what we know about the mycobacterial cell envelope has been gleaned from model actinobacterial species, or model conditions such as growth in vitro, in macrophages and in the mouse. In this Review, we combine data from different experimental systems to build a model of the dynamics of the mycobacterial cell envelope across space and time. We describe the regulatory pathways that control metabolism of the cell wall and surface lipids in M. tuberculosis during growth and stasis, and speculate about how this regulation might affect antibiotic susceptibility and interactions with the immune system.
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Affiliation(s)
- Charles L Dulberger
- Department of Molecular and Cellular Biology, Harvard University, Boston, MA, USA.,Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Eric J Rubin
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Cara C Boutte
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.
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15
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Gao CH, Wei WP, Tao HL, Cai LK, Jia WZ, Hu L, Yang M. Cross-talk between the three furA orthologs in Mycobacterium smegmatis and the contribution to isoniazid resistance. J Biochem 2019; 166:237-243. [PMID: 30993320 DOI: 10.1093/jb/mvz030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 04/10/2019] [Indexed: 01/18/2023] Open
Abstract
The ferric uptake regulator A (FurA) plays an essential role in responding to oxidative stress in mycobacteria. The genome of Mycobacterium smegmatis harbours three FurA orthologs; however, the potential cross-talk and contribution to drug resistance of different furA operon remain underdetermined. In this study, we characterized the cross-regulation and effect in drug resistance of these orthologs from M. smegmatis. Cross-binding of FurA protein to furA promoter was observed. The binding of FurA1 to furA3p and FurA2 to furA1p or furA3p is even more pronounced than their self-binding. The three FurA proteins are all functional at repressing the expression of the peroxidase enzyme katG1/katG2 in vivo. When overexpressing any of the furA orthologs in M. smegmatis, the bacteria become more resistant to isoniazid (INH). This pattern is consistent with that in Mycobacterium bovis. However, the knockdown of furA does not affect the INH sensitivity. This is the first report of cross-talk and contribution to drug resistance of all three furA orthologs in M. smegmatis.
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Affiliation(s)
- Chun-Hui Gao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, China
| | - Wen-Ping Wei
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, China
| | - Hui-Ling Tao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, China
| | - Li-Kai Cai
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, China
| | - Wan-Zhong Jia
- The State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, No. 1, Xujiaping, Chengguan District, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Lihua Hu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, China
| | - Min Yang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan, China
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16
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Vilchèze C, Jacobs WR. The Isoniazid Paradigm of Killing, Resistance, and Persistence in Mycobacterium tuberculosis. J Mol Biol 2019; 431:3450-3461. [PMID: 30797860 PMCID: PMC6703971 DOI: 10.1016/j.jmb.2019.02.016] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/05/2019] [Accepted: 02/11/2019] [Indexed: 12/20/2022]
Abstract
Isoniazid (INH) was the first synthesized drug that mediated bactericidal killing of the bacterium Mycobacterium tuberculosis, a major clinical breakthrough. To this day, INH remains a cornerstone of modern tuberculosis (TB) chemotherapy. This review describes the serendipitous discovery of INH, its effectiveness on TB patients, and early studies to discover its mechanisms of bacteriocidal activity. Forty years after its introduction as a TB drug, the development of gene transfer in mycobacteria enabled the discovery of the genes encoding INH resistance, namely, the activator (katG) and the target (inhA) of INH. Further biochemical and x-ray crystallography studies on KatG and InhA proteins and mutants provided comprehensive understanding of INH mode of action and resistance mechanisms. Bacterial cultures can harbor subpopulations that are genetically or phenotypically resistant cells, the latter known as persisters. Treatment of exponentially growing cultures of M. tuberculosis with INH reproducibly kills 99% to 99.9% of cells in 3 days. Importantly, the surviving cells are slowly replicating or non-replicating cells expressing a unique stress response signature: these are the persisters. These persisters can be visualized using dual-reporter mycobacteriophages and their formation prevented using reducing compounds, such as N-acetylcysteine or vitamin C, that enhance M. tuberculosis' respiration. Altogether, this review portrays a detailed molecular analysis of INH killing and resistance mechanisms including persistence. The phenomenon of persistence is clearly the single greatest impediment to TB control, and research aimed at understanding persistence will provide new strategies to improve TB chemotherapy.
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Affiliation(s)
- Catherine Vilchèze
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY 10461, USA
| | - William R Jacobs
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY 10461, USA.
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17
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Wang M, Gao H, Lin N, Zhang Y, Huang N, Walker ED, Ming D, Chen S, Hu S. The antibiotic resistance and pathogenicity of a multidrug-resistant Elizabethkingia anophelis isolate. Microbiologyopen 2019; 8:e804. [PMID: 30891912 PMCID: PMC6854844 DOI: 10.1002/mbo3.804] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/04/2019] [Accepted: 01/08/2019] [Indexed: 12/20/2022] Open
Abstract
Elizabethkingia anophelis 12012‐2 PRCM was isolated from a patient with multiple organ dysfunction syndrome and lower respiratory tract infection in China. Minimum inhibitory concentration (MIC) analysis demonstrated that it was resistant to 20 antibiotics including trimethoprim/sulfamethoxazole and ciprofloxacin, which were effective for the elimination of other Elizabethkingia infections. To investigate multidrug resistance and pathogenicity mechanisms, we analyzed genome features of 12012‐2 PRCM and compared them to the other Elizabethkingia species. The draft genome size was 4.02 Mb with a GC content of 32%, comparable to that of other E. anophelis strains. Phylogenetic analysis showed that E. anophelis 12012‐2 PRCM formed a sister group with E. anophelis 502, distinct from clades formed by other clinical and environmental E. anophelis isolates. E. anophelis 12012‐2 PRCM contained multiple copies of β‐lactamase genes as well as genes predicted to function in antimicrobial efflux. It also contained 92 genes that were potentially involved in virulence, disease, and defense, and were associated with resistance and pathogenicity. Comparative genomic analysis showed high homology among three clinical and two environmental E. anophelis strains having a variety of similar antibiotic resistance and virulence factor genes, and similar genomic structure. Applications of this analysis will contribute to understanding the antibiotic resistance and pathogenic mechanisms of E. anophelis infections, which will assist in the management of infections as it increases in prevalence.
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Affiliation(s)
- Mingxi Wang
- Yun Leung Laboratory for Molecular Diagnostics, School of Medicine, Huaqiao University, Xiamen, Fujian, China
| | - Hongzhi Gao
- Clinical Center for Molecular Diagnosis and Therapy, Fujian Medical University 2nd Affiliated Hospital, Quanzhou, Fujian, China
| | - Nanfei Lin
- Clinical Center for Molecular Diagnosis and Therapy, Fujian Medical University 2nd Affiliated Hospital, Quanzhou, Fujian, China
| | - Yaping Zhang
- Department of Pulmonary and Critical Care Medicine, Fujian Medical University 2nd Affiliated Hospital, Quanzhou, Fujian, China
| | - Nan Huang
- Quanzhou Medical College, Quanzhou, Fujian, China
| | - Edward D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
| | - Desong Ming
- Department of Clinical Laboratory, Quanzhou First Hospital Affiliated to Fujian Medical University, Fujian, China
| | - Shicheng Chen
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
| | - Shaohua Hu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital of Medical College, Zhejiang University, Hangzhou, Zhejiang, China
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18
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Sarvan S, Butcher J, Stintzi A, Couture JF. Variation on a theme: investigating the structural repertoires used by ferric uptake regulators to control gene expression. Biometals 2018; 31:681-704. [DOI: 10.1007/s10534-018-0120-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 06/12/2018] [Indexed: 11/29/2022]
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19
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da Silva RA, Pereira LDM, Silveira MC, Jardim R, de Miranda AB. Mining of potential drug targets through the identification of essential and analogous enzymes in the genomes of pathogens of Glycine max, Zea mays and Solanum lycopersicum. PLoS One 2018; 13:e0197511. [PMID: 29799863 PMCID: PMC5969768 DOI: 10.1371/journal.pone.0197511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/03/2018] [Indexed: 01/19/2023] Open
Abstract
Pesticides are one of the most widely used pest and disease control measures in plant crops and their indiscriminate use poses a direct risk to the health of populations and environment around the world. As a result, there is a great need for the development of new, less toxic molecules to be employed against plant pathogens. In this work, we employed an in silico approach to study the genes coding for enzymes of the genomes of three commercially important plants, soybean (Glycine max), tomato (Solanum lycopersicum) and corn (Zea mays), as well as 15 plant pathogens (4 bacteria and 11 fungi), focusing on revealing a set of essential and non-homologous isofunctional enzymes (NISEs) that could be prioritized as drug targets. By combining sequence and structural data, we obtained an initial set of 568 cases of analogy, of which 97 were validated and further refined, revealing a subset of 29 essential enzymatic activities with a total of 119 different structural forms, most belonging to central metabolic routes, including the carbohydrate metabolism, the metabolism of amino acids, among others. Further, another subset of 26 enzymatic activities possess a tertiary structure specific for the pathogen, not present in plants, men and Apis mellifera, which may be of importance for the development of specific enzymatic inhibitors against plant diseases that are less harmful to humans and the environment.
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Affiliation(s)
| | | | | | - Rodrigo Jardim
- Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
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20
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Lee HN, Ji CJ, Lee HH, Park J, Seo YS, Lee JW, Oh JI. Roles of three FurA paralogs in the regulation of genes pertaining to peroxide defense in Mycobacterium smegmatis mc 2 155. Mol Microbiol 2018; 108:661-682. [PMID: 29569300 DOI: 10.1111/mmi.13956] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2018] [Indexed: 11/28/2022]
Abstract
Mycobacterium smegmatis mc2 155 has three genes (MSMEG_6383, furA1; MSMEG_3460, furA2; MSMEG_6253, furA3) encoding FurA (ferric-uptake regulator A) paralogs. Three FurA paralogs in M. smegmatis are functionally redundant and negatively regulate expression of a subset of genes involved in peroxide detoxification such as ahpC, katG1 and katG2, as well as their own genes. The FurA paralogs sense H2 O2 via metal-catalyzed His oxidation (MCHO) in the same way as PerR. The propensity of FurA2 and FurA3 for MCHO is greater than that of FurA1. The three furA genes are transcribed into leaderless mRNAs lacking the Shine-Dalgarno (SD) sequence. FurA1 and FurA3 have the quaternary structure of homodimers like most Fur homologs, whereas FurA2 occurs as a monomer. The monomeric structure of FurA2 is determined by the C-terminal region of its dimerization domain. FurA2 monomers appear to cooperatively bind to the FurA-binding site with an inverted repeat configuration and have a broader binding specificity for the target DNA than dimeric FurA1 and FurA3. Comparative transcriptomic analysis revealed that the FurA paralogs do not regulate genes related to iron homeostasis in M. smegmatis, and that expression of SigF-regulated genes is significantly decreased in a furA triple mutant relative to the wild-type strain of M. smegmatis.
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Affiliation(s)
- Ha-Na Lee
- Department of Microbiology, Pusan National University, Busan, 46241, Korea
| | - Chang-Jun Ji
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul, 04763, Korea
| | - Hyun-Hee Lee
- Department of Microbiology, Pusan National University, Busan, 46241, Korea
| | - Jungwook Park
- Department of Microbiology, Pusan National University, Busan, 46241, Korea
| | - Young-Su Seo
- Department of Microbiology, Pusan National University, Busan, 46241, Korea
| | - Jin-Won Lee
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul, 04763, Korea
| | - Jeong-Il Oh
- Department of Microbiology, Pusan National University, Busan, 46241, Korea
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Nieto R LM, Mehaffy C, Creissen E, Troudt J, Troy A, Bielefeldt-Ohmann H, Burgos M, Izzo A, Dobos KM. Virulence of Mycobacterium tuberculosis after Acquisition of Isoniazid Resistance: Individual Nature of katG Mutants and the Possible Role of AhpC. PLoS One 2016; 11:e0166807. [PMID: 27893795 PMCID: PMC5125630 DOI: 10.1371/journal.pone.0166807] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 11/03/2016] [Indexed: 11/28/2022] Open
Abstract
In the last decade, there were 10 million new tuberculosis cases per year globally. Around 9.5% of these cases were caused by isoniazid resistant (INHr) Mycobacterium tuberculosis (Mtb) strains. Although isoniazid resistance in Mtb is multigenic, mutations in the catalase-peroxidase (katG) gene predominate among the INHr strains. The effect of these drug-resistance-conferring mutations on Mtb fitness and virulence is variable. Here, we assessed differences in bacterial growth, immune response and pathology induced by Mtb strains harboring mutations at the N-terminus of the katG gene. We studied one laboratory and one clinically isolated Mtb clonal pair from different genetic lineages. The INHr strain in each pair had one and two katG mutations with significantly reduced levels of the enzyme and peroxidase activity. Both strains share the V1A mutation, while the double mutant clinical INHr had also the novel E3V katG mutation. Four groups of C57BL/6 mice were infected with one of the Mtb strains previously described. We observed a strong reduction in virulence (reduced bacterial growth), lower induction of proinflammatory cytokines and significantly reduced pathology scores in mice infected with the clinical INHr strain compared to the infection caused by its INHs progenitor strain. On the other hand, there was a subtle reduction of bacteria growth without differences in the pathology scores in mice infected with the laboratory INHr strain. Our results also showed distinct alkyl-hydroperoxidase C (AhpC) levels in the katG mutant strains, which could explain the difference in the virulence profile observed. The difference in the AhpC levels between clonal strains was not related to a genetic defect in the gene or its promoter. Cumulatively, our results indicate that the virulence, pathology and fitness of INHr strains could be negatively affected by multiple mutations in katG, lack of the peroxidase activity and reduced AhpC levels.
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Affiliation(s)
- Luisa Maria Nieto R
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Carolina Mehaffy
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Elizabeth Creissen
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - JoLynn Troudt
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Amber Troy
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Helle Bielefeldt-Ohmann
- School of Veterinary Science, University of Queensland, Gatton, Queensland, Australia; Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Marcos Burgos
- Division of Infectious Diseases, Department of Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Angelo Izzo
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Karen M. Dobos
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
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22
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McLean KJ, Munro AW. Drug targeting of heme proteins in Mycobacterium tuberculosis. Drug Discov Today 2016; 22:566-575. [PMID: 27856345 DOI: 10.1016/j.drudis.2016.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 10/28/2016] [Accepted: 11/02/2016] [Indexed: 01/08/2023]
Abstract
TB, caused by the human pathogen Mycobacterium tuberculosis (Mtb), causes more deaths than any other infectious disease. Iron is crucial for Mtb to infect the host and to sustain infection, with Mtb encoding large numbers of iron-binding proteins. Many of these are hemoproteins with key roles, including defense against oxidative stress, cellular signaling and regulation, host cholesterol metabolism, and respiratory processes. Various heme enzymes in Mtb are validated drug targets and/or products of genes essential for bacterial viability or survival in the host. Here, we review the structure, function, and druggability of key Mtb heme enzymes and strategies used for their inhibition.
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Affiliation(s)
- Kirsty J McLean
- School of Chemistry, The University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK
| | - Andrew W Munro
- School of Chemistry, The University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK.
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23
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Overview on mechanisms of isoniazid action and resistance in Mycobacterium tuberculosis. INFECTION GENETICS AND EVOLUTION 2016; 45:474-492. [DOI: 10.1016/j.meegid.2016.09.004] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/02/2016] [Accepted: 09/03/2016] [Indexed: 12/17/2022]
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Brossier F, Boudinet M, Jarlier V, Petrella S, Sougakoff W. Comparative study of enzymatic activities of new KatG mutants from low- and high-level isoniazid-resistant clinical isolates of Mycobacterium tuberculosis. Tuberculosis (Edinb) 2016; 100:15-24. [DOI: 10.1016/j.tube.2016.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 05/08/2016] [Accepted: 06/05/2016] [Indexed: 11/29/2022]
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Role of Metal-Dependent Regulation of ESX-3 Secretion in Intracellular Survival of Mycobacterium tuberculosis. Infect Immun 2016; 84:2255-2263. [PMID: 27245412 DOI: 10.1128/iai.00197-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/19/2016] [Indexed: 12/31/2022] Open
Abstract
More people die every year from Mycobacterium tuberculosis infection than from infection by any other bacterial pathogen. Type VII secretion systems (T7SS) are used by both environmental and pathogenic mycobacteria to secrete proteins across their complex cell envelope. In the nonpathogen Mycobacterium smegmatis, the ESX-1 T7SS plays a role in conjugation, and the ESX-3 T7SS is involved in metal homeostasis. In M. tuberculosis, these secretion systems have taken on roles in virulence, and they also are targets of the host immune response. ESX-3 secretes a heterodimer composed of EsxG (TB9.8) and EsxH (TB10.4), which impairs phagosome maturation in macrophages and is essential for virulence in mice. Given the importance of EsxG and EsxH during infection, we examined their regulation. With M. tuberculosis, the secretion of EsxG and EsxH was regulated in response to iron and zinc, in accordance with the previously described transcriptional response of the esx-3 locus to these metals. While iron regulated the esx-3 expression in both M. tuberculosis and M. smegmatis, there is a significant difference in the dynamics of this regulation. In M. smegmatis, the esx-3 locus behaved like other iron-regulated genes such as mbtB In M. tuberculosis, both iron and zinc modestly repressed esx-3 expression. Diminished secretion of EsxG and EsxH in response to these metals altered the interaction of M. tuberculosis with macrophages, leading to impaired intracellular M. tuberculosis survival. Our findings detail the regulatory differences of esx-3 in M. tuberculosis and M. smegmatis and demonstrate the importance of metal-dependent regulation of ESX-3 for virulence in M. tuberculosis.
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Resistance to Isoniazid and Ethionamide in Mycobacterium tuberculosis: Genes, Mutations, and Causalities. Microbiol Spectr 2016; 2:MGM2-0014-2013. [PMID: 26104204 DOI: 10.1128/microbiolspec.mgm2-0014-2013] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Isoniazid (INH) is the cornerstone of tuberculosis (TB) chemotherapy, used for both treatment and prophylaxis of TB. The antimycobacterial activity of INH was discovered in 1952, and almost as soon as its activity was published, the first INH-resistant Mycobacterium tuberculosis strains were reported. INH and its structural analog and second-line anti-TB drug ethionamide (ETH) are pro-drugs. INH is activated by the catalase-peroxidase KatG, while ETH is activated by the monooxygenase EthA. The resulting active species reacts with NAD+ to form an INH-NAD or ETH-NAD adduct, which inhibits the enoyl ACP reductase InhA, leading to mycolic acid biosynthesis inhibition and mycobacterial cell death. The major mechanism of INH resistance is mutation in katG, encoding the activator of INH. One specific KatG variant, S315T, is found in 94% of INH-resistant clinical isolates. The second mechanism of INH resistance is a mutation in the promoter region of inhA (c-15t), which results in inhA overexpression and leads to titration of the drug. Mutations in the inhA open reading frame and promoter region are also the major mechanism of resistance to ETH, found more often in ETH-resistant clinical isolates than mutations in the activator of ETH. Other mechanisms of resistance to INH and ETH include expression changes of the drugs' activators, redox alteration, drug inactivation, and efflux pump activation. In this article, we describe each known mechanism of resistance to INH and ETH and its importance in M. tuberculosis clinical isolates.
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Hillion M, Antelmann H. Thiol-based redox switches in prokaryotes. Biol Chem 2016; 396:415-44. [PMID: 25720121 DOI: 10.1515/hsz-2015-0102] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/05/2015] [Indexed: 12/12/2022]
Abstract
Bacteria encounter reactive oxygen species (ROS) as a consequence of the aerobic life or as an oxidative burst of activated neutrophils during infections. In addition, bacteria are exposed to other redox-active compounds, including hypochloric acid (HOCl) and reactive electrophilic species (RES) such as quinones and aldehydes. These reactive species often target the thiol groups of cysteines in proteins and lead to thiol-disulfide switches in redox-sensing regulators to activate specific detoxification pathways and to restore the redox balance. Here, we review bacterial thiol-based redox sensors that specifically sense ROS, RES and HOCl via thiol-based mechanisms and regulate gene transcription in Gram-positive model bacteria and in human pathogens, such as Staphylococcus aureus and Mycobacterium tuberculosis. We also pay particular attention to emerging widely conserved HOCl-specific redox regulators that have been recently characterized in Escherichia coli. Different mechanisms are used to sense and respond to ROS, RES and HOCl by 1-Cys-type and 2-Cys-type thiol-based redox sensors that include versatile thiol-disulfide switches (OxyR, OhrR, HypR, YodB, NemR, RclR, Spx, RsrA/RshA) or alternative Cys phosphorylations (SarZ, MgrA, SarA), thiol-S-alkylation (QsrR), His-oxidation (PerR) and methionine oxidation (HypT). In pathogenic bacteria, these redox-sensing regulators are often important virulence regulators and required for adapation to the host immune defense.
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Li Q, Fu T, Li C, Fan X, Xie J. Mycobacterial IclR family transcriptional factor Rv2989 is specifically involved in isoniazid tolerance by regulating the expression of catalase encoding gene katG. RSC Adv 2016. [DOI: 10.1039/c6ra07733a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Transcriptional factors are essential for bacteria to adapt diverse environmental stresses, especially upon exposure to antibiotics.
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Affiliation(s)
- Qiming Li
- Institute of Modern Biopharmaceuticals
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region
- Ministry of Education
- School of Life Sciences
| | - Tiwei Fu
- Institute of Modern Biopharmaceuticals
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region
- Ministry of Education
- School of Life Sciences
| | - Chunyan Li
- Institute of Modern Biopharmaceuticals
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region
- Ministry of Education
- School of Life Sciences
| | - Xiangyu Fan
- Institute of Modern Biopharmaceuticals
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region
- Ministry of Education
- School of Life Sciences
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region
- Ministry of Education
- School of Life Sciences
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Rustad TR, Minch KJ, Ma S, Winkler JK, Hobbs S, Hickey M, Brabant W, Turkarslan S, Price ND, Baliga NS, Sherman DR. Mapping and manipulating the Mycobacterium tuberculosis transcriptome using a transcription factor overexpression-derived regulatory network. Genome Biol 2015; 15:502. [PMID: 25380655 DOI: 10.1186/preaccept-1701638048134699] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mycobacterium tuberculosis senses and responds to the shifting and hostile landscape of the host. To characterize the underlying intertwined gene regulatory network governed by approximately 200 transcription factors of M. tuberculosis, we have assayed the global transcriptional consequences of overexpressing each transcription factor from an inducible promoter. RESULTS We cloned and overexpressed 206 transcription factors in M. tuberculosis to identify the regulatory signature of each. We identified 9,335 regulatory consequences of overexpressing each of 183 transcription factors, providing evidence of regulation for 70% of the M. tuberculosis genome. These transcriptional signatures agree well with previously described M. tuberculosis regulons. The number of genes differentially regulated by transcription factor overexpression varied from hundreds of genes to none, with the majority of expression changes repressing basal transcription. Exploring the global transcriptional maps of transcription factor overexpressing (TFOE) strains, we predicted and validated the phenotype of a regulator that reduces susceptibility to a first line anti-tubercular drug, isoniazid. We also combined the TFOE data with an existing model of M. tuberculosis metabolism to predict the growth rates of individual TFOE strains with high fidelity. CONCLUSION This work has led to a systems-level framework describing the transcriptome of a devastating bacterial pathogen, characterized the transcriptional influence of nearly all individual transcription factors in M. tuberculosis, and demonstrated the utility of this resource. These results will stimulate additional systems-level and hypothesis-driven efforts to understand M. tuberculosis adaptations that promote disease.
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Rustad TR, Minch KJ, Ma S, Winkler JK, Hobbs S, Hickey M, Brabant W, Turkarslan S, Price ND, Baliga NS, Sherman DR. Mapping and manipulating the Mycobacterium tuberculosis transcriptome using a transcription factor overexpression-derived regulatory network. Genome Biol 2015. [PMID: 25380655 PMCID: PMC4249609 DOI: 10.1186/s13059-014-0502-3] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background Mycobacterium tuberculosis senses and responds to the shifting and hostile landscape of the host. To characterize the underlying intertwined gene regulatory network governed by approximately 200 transcription factors of M. tuberculosis, we have assayed the global transcriptional consequences of overexpressing each transcription factor from an inducible promoter. Results We cloned and overexpressed 206 transcription factors in M. tuberculosis to identify the regulatory signature of each. We identified 9,335 regulatory consequences of overexpressing each of 183 transcription factors, providing evidence of regulation for 70% of the M. tuberculosis genome. These transcriptional signatures agree well with previously described M. tuberculosis regulons. The number of genes differentially regulated by transcription factor overexpression varied from hundreds of genes to none, with the majority of expression changes repressing basal transcription. Exploring the global transcriptional maps of transcription factor overexpressing (TFOE) strains, we predicted and validated the phenotype of a regulator that reduces susceptibility to a first line anti-tubercular drug, isoniazid. We also combined the TFOE data with an existing model of M. tuberculosis metabolism to predict the growth rates of individual TFOE strains with high fidelity. Conclusion This work has led to a systems-level framework describing the transcriptome of a devastating bacterial pathogen, characterized the transcriptional influence of nearly all individual transcription factors in M. tuberculosis, and demonstrated the utility of this resource. These results will stimulate additional systems-level and hypothesis-driven efforts to understand M. tuberculosis adaptations that promote disease. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0502-3) contains supplementary material, which is available to authorized users.
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Kruft BI, Magliozzo RS, Jarzęcki AA. Density Functional Theory Insights into the Role of the Methionine–Tyrosine–Tryptophan Adduct Radical in the KatG Catalase Reaction: O2 Release from the Oxyheme Intermediate. J Phys Chem A 2015; 119:6850-66. [DOI: 10.1021/jp511358p] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Bonnie I. Kruft
- Department of Chemistry, Brooklyn College, Brooklyn, New York 11210, United States
- The Graduate Center, City University of New York, Brooklyn, New York 10016, United States
| | - Richard S. Magliozzo
- Department of Chemistry, Brooklyn College, Brooklyn, New York 11210, United States
- The Graduate Center, City University of New York, Brooklyn, New York 10016, United States
| | - Andrzej A. Jarzęcki
- Department of Chemistry, Brooklyn College, Brooklyn, New York 11210, United States
- The Graduate Center, City University of New York, Brooklyn, New York 10016, United States
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32
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Campen RL, Ackerley DF, Cook GM, O'Toole RF. Development of a Mycobacterium smegmatis transposon mutant array for characterising the mechanism of action of tuberculosis drugs: Findings with isoniazid and its structural analogues. Tuberculosis (Edinb) 2015; 95:432-9. [PMID: 25936537 DOI: 10.1016/j.tube.2015.03.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 03/23/2015] [Accepted: 03/29/2015] [Indexed: 01/31/2023]
Abstract
The development of new drugs is required to control human tuberculosis (TB). This study examined whether drug hypersensitive mutants could be used to reveal novel aspects of the mechanism of action of a TB drug. A transposon mutant collection with an estimated 1.1-fold genome coverage (7680 mutants) was constructed in Mycobacterium smegmatis and screened in high-throughput against isoniazid. Hypersensitive transposants with mutations in genes known to influence the mode of action of isoniazid were isolated. To further investigate the role of one of these genes, nudC, the corresponding mutant was tested for sensitivity towards isoniazid structural analogues. Overexpression of nudC, as well as inhA which encodes a known target of isoniazid, increased M. smegmatis resistance to isoniazid, but failed to increase resistance to three of the analogues, NSC27607, NSC33759, and NSC40350. In contrast, overexpression of katG resulted in increased sensitivity to each of the isoniazid analogues tested including NSC27607, NSC33759, and NSC40350. This provides evidence that the latter isoniazid analogues are activated by KatG in a NudC-independent manner and that InhA may not be their primary target. In summary, characterisation of drug hypersensitive mutants detected genes involved in the mode of action of isoniazid. Furthermore, it identified isoniazid analogues which are resilient to both InhA- and NudC-dependent mechanisms of resistance.
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Affiliation(s)
- Richard L Campen
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand
| | - David F Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, 9016, New Zealand
| | - Ronan F O'Toole
- Breathe Well NHMRC Centre of Research Excellence, School of Medicine, University of Tasmania, Hobart, TAS, 7000, Australia.
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Eckelt E, Meißner T, Meens J, Laarmann K, Nerlich A, Jarek M, Weiss S, Gerlach GF, Goethe R. FurA contributes to the oxidative stress response regulation of Mycobacterium avium ssp. paratuberculosis. Front Microbiol 2015; 6:16. [PMID: 25705205 PMCID: PMC4319475 DOI: 10.3389/fmicb.2015.00016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 01/07/2015] [Indexed: 11/13/2022] Open
Abstract
The ferric uptake regulator A (FurA) is known to be involved in iron homeostasis and stress response in many bacteria. In mycobacteria the precise role of FurA is still unclear. In the presented study, we addressed the functional role of FurA in the ruminant pathogen Mycobacterium avium ssp. paratuberculosis (MAP) by construction of a furA deletion strain (MAPΔfurA). RNA deep sequencing revealed that the FurA regulon consists of repressed and activated genes associated to stress response or intracellular survival. Not a single gene related to metal homeostasis was affected by furA deletion. A decisive role of FurA during intracellular survival in macrophages was shown by significantly enhanced survival of MAPΔfurA compared to the wildtype, indicating that a principal task of mycobacterial FurA is oxidative stress response regulation in macrophages. This resistance was not associated with altered survival of mice after long term infection with MAP. Our results demonstrate for the first time, that mycobacterial FurA is not involved in the regulation of iron homeostasis. However, they provide strong evidence that FurA contributes to intracellular survival as an oxidative stress sensing regulator.
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Affiliation(s)
- Elke Eckelt
- Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover Hannover, Germany
| | - Thorsten Meißner
- Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover Hannover, Germany
| | - Jochen Meens
- Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover Hannover, Germany
| | - Kristin Laarmann
- Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover Hannover, Germany
| | - Andreas Nerlich
- Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover Hannover, Germany
| | - Michael Jarek
- Genome Analytics, Helmholtz Centre for Infection Research Braunschweig, Germany
| | - Siegfried Weiss
- Molecular Immunology, Helmholtz Centre for Infection Research Braunschweig, Germany
| | - Gerald-F Gerlach
- Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover Hannover, Germany
| | - Ralph Goethe
- Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover Hannover, Germany
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Fang Z, Sampson SL, Warren RM, Gey van Pittius NC, Newton-Foot M. Iron acquisition strategies in mycobacteria. Tuberculosis (Edinb) 2015; 95:123-30. [PMID: 25636179 DOI: 10.1016/j.tube.2015.01.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 01/01/2015] [Accepted: 01/07/2015] [Indexed: 02/04/2023]
Abstract
Iron is an essential element to most life forms including mycobacterial species. However, in the oxidative atmosphere iron exists as insoluble salts. Free and soluble iron ions are scarce in both the extracellular and intracellular environment which makes iron assimilation very challenging to mycobacteria. Tuberculosis, caused by the pathogen, Mycobacterium tuberculosis, is one of the most infectious and deadly diseases in the world. Extensive studies regarding iron acquisition strategies have been documented in mycobacteria, including work on the mycobacterial iron chelators (siderophores), the iron-responsive regulon, and iron transport and utilization pathways. Under low iron conditions, expression of the genes encoding iron importers, exporters and siderophore biosynthetic enzymes is up-regulated significantly increasing the ability of the bacteria to acquire limited host iron. Disabling these proteins impairs the growth of mycobacteria under low iron conditions both in vitro and in vivo, and that of pathogenic mycobacteria in animal models. Drugs targeting siderophore-mediated iron transport could offer promising therapeutic options. However, the discovery and characterization of an alternative iron acquisition mechanism, the heme transport and utilization pathway, questions the effectiveness of the siderophore-centered therapeutic strategy. Links have been found between these two distinct iron acquisition mechanisms, thus, targeting a few candidate proteins or mechanisms may influence both pathways, leading to effective elimination of the bacteria in the host.
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Affiliation(s)
- Zhuo Fang
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, US/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Stellenbosch, Francie van Zijl Drive, Tygerberg, 7505, South Africa.
| | - Samantha Leigh Sampson
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, US/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Stellenbosch, Francie van Zijl Drive, Tygerberg, 7505, South Africa.
| | - Robin Mark Warren
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, US/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Stellenbosch, Francie van Zijl Drive, Tygerberg, 7505, South Africa.
| | - Nicolaas Claudius Gey van Pittius
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, US/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Stellenbosch, Francie van Zijl Drive, Tygerberg, 7505, South Africa.
| | - Mae Newton-Foot
- Division of Medical Microbiology, Department of Pathology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Francie van Zijl Drive, Tygerberg, 7505, South Africa.
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Ameeruddin NU, Luke Elizabeth H. Impact of isoniazid resistance on virulence of global and south Indian clinical isolates of Mycobacterium tuberculosis. Tuberculosis (Edinb) 2014; 94:557-63. [DOI: 10.1016/j.tube.2014.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 08/18/2014] [Accepted: 08/19/2014] [Indexed: 12/22/2022]
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Lee HN, Lee NO, Han SJ, Ko IJ, Oh JI. Regulation of the ahpC gene encoding alkyl hydroperoxide reductase in Mycobacterium smegmatis. PLoS One 2014; 9:e111680. [PMID: 25365321 PMCID: PMC4218801 DOI: 10.1371/journal.pone.0111680] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 09/29/2014] [Indexed: 12/04/2022] Open
Abstract
The ahpC (MSMEG_4891) gene encodes alkyl hydroperoxide reductase C in Mycobacterium smegmatis mc2155 and its expression is induced under oxidative stress conditions. Two well-defined inverted repeat sequences (IR1 and IR2) were identified in the upstream region of ahpC. Using a crp (cAMP receptor protein: MSMEG_6189) mutant and in vitro DNA-binding assay, it was demonstrated that the IR1 sequence serves as a Crp-binding site and that Crp functions as an activator in the regulation of ahpC expression. The expression level of ahpC was shown to be proportional to intracellular cAMP levels. Intracellular levels of cAMP were increased in M. smegmatis, when it was treated with oxidative stress inducers. The IR2 sequence is very similar to the known consensus sequence of FurA-binding sites and involved in the negative regulation of ahpC expression. Taken together, these results suggest that the induction of ahpC expression under oxidative stress conditions probably results from a combinatory effect of both inactivation of FurA by oxidative stress and activation of Crp in response to increased levels of cAMP.
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Affiliation(s)
- Ha-Na Lee
- Department of Microbiology, Pusan National University, Busan, Korea
| | - Na-On Lee
- Department of Microbiology, Pusan National University, Busan, Korea
| | - Seung J. Han
- Department of Microbiology and Institute for Immunology and Immunological Diseases, Yonsei University, Seoul, Korea
| | - In-Jeong Ko
- Korea Science Academy of KAIST, Busan, Korea
| | - Jeong-Il Oh
- Department of Microbiology, Pusan National University, Busan, Korea
- * E-mail:
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An upstream truncation of the furA-katG operon confers high-level isoniazid resistance in a Mycobacterium tuberculosis clinical isolate with no known resistance-associated mutations. Antimicrob Agents Chemother 2014; 58:6093-100. [PMID: 25092698 DOI: 10.1128/aac.03277-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although the major causes of isoniazid (INH) resistance in Mycobacterium tuberculosis are confined to structural mutations in katG and promoter mutations in the mabA-inhA operon, a significant proportion of INH-resistant strains have unknown resistance mechanisms. Recently, we identified a high-level INH-resistant M. tuberculosis clinical isolate, GB005, with no known resistance-associated mutations. A comprehensive study was performed to investigate the molecular basis of drug resistance in this strain. Although no mutations were found throughout the katG and furA-katG intergenic region, the katG expression and the catalase activity were greatly diminished compared to those in H37Rv (P < 0.01). Northern blotting revealed that the katG transcript from the isolate was smaller than that of H37Rv. Sequencing analysis of furA and upstream genes discovered a 7.2-kb truncation extended from the 96th base preceding the initiation codon of katG. Complementation of the M. tuberculosis Δ(furA-katG) strain with katG and different portions of the truncated region identified a 134-bp upstream fragment of furA that was essential for full catalase activity and INH susceptibility in M. tuberculosis. The promoter activity of this fragment was also shown to be stronger than that of the furA-katG intergenic region (P < 0.01). Collectively, these findings demonstrate that deletion of the 134-bp furA upstream fragment is responsible for the reduction in katG expression, resulting in INH resistance in GB005. To our knowledge, this is the first report showing that deletion of the upstream region preceding the furA-katG operon causes high-level INH resistance in a clinical isolate of M. tuberculosis.
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Bertrand RL. Lag phase-associated iron accumulation is likely a microbial counter-strategy to host iron sequestration: role of the ferric uptake regulator (fur). J Theor Biol 2014; 359:72-9. [PMID: 24929040 DOI: 10.1016/j.jtbi.2014.05.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 05/19/2014] [Accepted: 05/27/2014] [Indexed: 01/26/2023]
Abstract
Iron is an essential metal for almost all forms of life, but potentiates oxidative stress via Fenton catalysis. During microbial lag phase there is a rapid influx of iron with concomitant oxidative hypersensitivity. How and why iron accumulation occurs remains to be elucidated. Iron homeostasis in prokaryotes is mediated by the ferric uptake regulator (Fur), an iron-activated global regulator that controls intracellular iron levels by feedback inhibition with the metal. Herein it is postulated, based on the expression profiles of antioxidant enzymes within the Fur regulon as observed in wild type and Δfur mutants, that iron accumulation is mediated by a transitively low concentration of the Fur protein during lag phase. Vertebrate hosts sequester iron upon 'sensing' an infection in order to retard microbial proliferation through a process known as 'nutritional immunity'. It is herein argued that the purpose of iron accumulation is not principally a preparative step for the replicative phase, as suggested elsewhere, but an evolved behavior that counteracts host iron sequestration. This interpretation is supported by multiple clinical and animal studies that demonstrate that iron surplus in hosts advances progression and susceptibility to infection, and vice versa. Contextualizing iron accumulation as a counter-immune behavior adds impetus to the development of antibiotics targeting pathogenic modes of iron acquisition.
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Affiliation(s)
- Robert L Bertrand
- Department of Chemistry, University of Winnipeg, Winnipeg, MB, Canada R3B 2E9.
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Rodriguez GM, Neyrolles O. Metallobiology of Tuberculosis. Microbiol Spectr 2014; 2:10.1128/microbiolspec.MGM2-0012-2013. [PMID: 26103977 PMCID: PMC5180607 DOI: 10.1128/microbiolspec.mgm2-0012-2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Indexed: 11/20/2022] Open
Abstract
Transition metals are essential constituents of all living organisms, playing crucial structural and catalytic parts in many enzymes and transcription factors. However, transition metals can also be toxic when present in excess. Their uptake and efflux rates must therefore be carefully controlled by biological systems. In this chapter, we summarize the current knowledge about uptake and efflux systems in Mycobacterium tuberculosis for mainly three of these metals, namely iron, zinc, and copper. We also propose questions for future research in the field of metallobiology of host-pathogen interactions in tuberculosis.
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Affiliation(s)
- G. Marcela Rodriguez
- Public Health Research Institute Center & Department of Medicine, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103
| | - Olivier Neyrolles
- Centre National de la Recherche Scientifique & Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France
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Nebenzahl-Guimaraes H, Jacobson KR, Farhat MR, Murray MB. Systematic review of allelic exchange experiments aimed at identifying mutations that confer drug resistance in Mycobacterium tuberculosis. J Antimicrob Chemother 2013; 69:331-42. [PMID: 24055765 DOI: 10.1093/jac/dkt358] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Improving our understanding of the relationship between the genotype and the drug resistance phenotype of Mycobacterium tuberculosis will aid the development of more accurate molecular diagnostics for drug-resistant tuberculosis. Studies that use direct genetic manipulation to identify the mutations that cause M. tuberculosis drug resistance are superior to associational studies in elucidating an individual mutation's contribution to the drug resistance phenotype. METHODS We systematically reviewed the literature for publications reporting allelic exchange experiments in any of the resistance-associated M. tuberculosis genes. We included studies that introduced single point mutations using specialized linkage transduction or site-directed/in vitro mutagenesis and documented a change in the resistance phenotype. RESULTS We summarize evidence supporting the causal relationship of 54 different mutations in eight genes (katG, inhA, kasA, embB, embC, rpoB, gyrA and gyrB) and one intergenic region (furA-katG) with resistance to isoniazid, the rifamycins, ethambutol and fluoroquinolones. We observed a significant role for the strain genomic background in modulating the resistance phenotype of 21 of these mutations and found examples of where the same drug resistance mutations caused varying levels of resistance to different members of the same drug class. CONCLUSIONS This systematic review highlights those mutations that have been shown to causally change phenotypic resistance in M. tuberculosis and brings attention to a notable lack of allelic exchange data for several of the genes known to be associated with drug resistance.
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Teramoto H, Inui M, Yukawa H. OxyR acts as a transcriptional repressor of hydrogen peroxide-inducible antioxidant genes in Corynebacterium glutamicum R. FEBS J 2013; 280:3298-312. [PMID: 23621709 DOI: 10.1111/febs.12312] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 04/02/2013] [Accepted: 04/24/2013] [Indexed: 12/13/2022]
Abstract
OxyR, a LysR-type transcriptional regulator, has been established as a redox-responsive activator of antioxidant genes in bacteria. This study shows that OxyR acts as a transcriptional repressor of katA, dps, ftn and cydA in Corynebacterium glutamicum R. katA encodes H2O2-detoxifing enzyme catalase, dps and ftn are implicated in iron homeostasis and cydA encodes a subunit of cytochrome bd oxidase. Quantitative RT-PCR analyses revealed that expression of katA and dps, but not of ftn and cydA, was induced by H2O2. Disruption of the oxyR gene encoding OxyR resulted in a marked increase in katA and dps mRNAs to a level higher than that induced by H2O2, and the oxyR-deficient mutant showed a H2O2-resistant phenotype. This is in contrast to the conventional OxyR-dependent regulatory model. ftn and cydA were also upregulated by oxyR disruption but to a smaller extent. Electrophoretic mobility shift assays revealed that the OxyR protein specifically binds to all four upstream regions of the respective genes under reducing conditions. We observed that the oxidized form of OxyR similarly bound to not only the target promoter regions, but also nonspecific DNA fragments. Based on these findings, we propose that the transcriptional repression by OxyR is alleviated under oxidative stress conditions in a titration mechanism due to the decreased specificity of its DNA-binding activity. DNase I footprinting analyses revealed that the OxyR-binding site in the four target promoters is ~ 50 bp in length and has multiple T-N11-A motifs, a feature of LysR-type transcriptional regulators, but no significant overall sequence conservation.
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Affiliation(s)
- Haruhiko Teramoto
- Research Institute of Innovative Technology for the Earth, Kyoto, Japan
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Uplekar S, Rougemont J, Cole ST, Sala C. High-resolution transcriptome and genome-wide dynamics of RNA polymerase and NusA in Mycobacterium tuberculosis. Nucleic Acids Res 2012; 41:961-77. [PMID: 23222129 PMCID: PMC3553938 DOI: 10.1093/nar/gks1260] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
To construct a regulatory map of the genome of the human pathogen, Mycobacterium tuberculosis, we applied two complementary high-resolution approaches: strand-specific RNA-seq, to survey the global transcriptome, and ChIP-seq, to monitor the genome-wide dynamics of RNA polymerase (RNAP) and the anti-terminator NusA. Although NusA does not bind directly to DNA, but rather to RNAP and/or to the nascent transcript, we demonstrate that NusA interacts with RNAP ubiquitously throughout the chromosome, and that its profile mirrors RNAP distribution in both the exponential and stationary phases of growth. Generally, promoter-proximal peaks for RNAP and NusA were observed, followed by a decrease in signal strength reflecting transcriptional polarity. Differential binding of RNAP and NusA in the two growth conditions correlated with transcriptional activity as reflected by RNA abundance. Indeed, a significant association between expression levels and the presence of NusA throughout the gene body was detected, confirming the peculiar transcription-promoting role of NusA. Integration of the data sets pinpointed transcriptional units, mapped promoters and uncovered new anti-sense and non-coding transcripts. Highly expressed transcriptional units were situated mainly on the leading strand, despite the relatively unbiased distribution of genes throughout the genome, thus helping the replicative and transcriptional complexes to align.
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Affiliation(s)
- Swapna Uplekar
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Station 19, CH-1015 Lausanne, Switzerland
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Newton-Foot M, Gey van Pittius NC. The complex architecture of mycobacterial promoters. Tuberculosis (Edinb) 2012; 93:60-74. [PMID: 23017770 DOI: 10.1016/j.tube.2012.08.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 07/31/2012] [Accepted: 08/06/2012] [Indexed: 01/02/2023]
Abstract
The genus Mycobacterium includes a variety of species with differing phenotypic properties, including growth rate, pathogenicity and environment- and host-specificity. Although many mycobacterial species have been extensively studied and their genomes sequenced, the reasons for phenotypic variation between closely related species remain unclear. Variation in gene expression may contribute to these characteristics and enable the bacteria to respond to changing environmental conditions. Gene expression is controlled primarily at the level of transcription, where the main element of regulation is the promoter. Transcriptional regulation and associated promoter sequences have been studied extensively in E. coli. This review describes the complex structure and characteristics of mycobacterial promoters, in comparison to the classical E. coli prokaryotic promoter structure. Some components of mycobacterial promoters are similar to those of E. coli. These include the predominant guanine residue at the transcriptional start point, conserved -10 hexamer, similar interhexameric distances, the use of ATG as a start codon, the guanine- and adenine-rich ribosome binding site and the presence of extended -10 (TGn) motifs in strong promoters. However, these components are much more variable in sequence in mycobacterial promoters and no conserved -35 hexamer sequence (clearly defined in E. coli) can be identified. This may be a result of the high G+C content of mycobacterial genomes, as well as the large number of sigma factors present in mycobacteria, which may recognise different promoter sequences. Mycobacteria possess a complex transcriptional regulatory network. Numerous regulatory motifs have been identified in mycobacterial promoters, predominantly in the interhexameric region. These are bound by specific transcriptional regulators in response to environmental changes. The combination of specific promoter sequences, transcriptional regulators and a variety of sigma factors enables rapid and specific responses to diverse conditions and different stages of infection. This review aims to provide an overview of the complex architecture of mycobacterial transcriptional regulation.
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Affiliation(s)
- Mae Newton-Foot
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 19063, Francie van Zijl Drive, Tygerberg 7505, South Africa.
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Niki M, Niki M, Tateishi Y, Ozeki Y, Kirikae T, Lewin A, Inoue Y, Matsumoto M, Dahl JL, Ogura H, Kobayashi K, Matsumoto S. A novel mechanism of growth phase-dependent tolerance to isoniazid in mycobacteria. J Biol Chem 2012; 287:27743-52. [PMID: 22648414 DOI: 10.1074/jbc.m111.333385] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Tuberculosis remains one of the most deadly infectious diseases worldwide and is a leading public health problem. Although isoniazid (INH) is a key drug for the treatment of tuberculosis, tolerance to INH necessitates prolonged treatment, which is a concern for effective tuberculosis chemotherapy. INH is a prodrug that is activated by the mycobacterial enzyme, KatG. Here, we show that mycobacterial DNA-binding protein 1 (MDP1), which is a histone-like protein conserved in mycobacteria, negatively regulates katG transcription and leads to phenotypic tolerance to INH in mycobacteria. Mycobacterium smegmatis deficient for MDP1 exhibited increased expression of KatG and showed enhanced INH activation compared with the wild-type strain. Expression of MDP1 was increased in the stationary phase and conferred growth phase-dependent tolerance to INH in M. smegmatis. Regulation of KatG expression is conserved between M. smegmatis and Mycobacterium tuberculosis complex. Artificial reduction of MDP1 in Mycobacterium bovis BCG was shown to lead to increased KatG expression and susceptibility to INH. These data suggest a mechanism by which phenotypic tolerance to INH is acquired in mycobacteria.
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Affiliation(s)
- Makoto Niki
- Department of Bacteriology, Virology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Osaka 545-8585, Japan
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Li Y, He ZG. The mycobacterial LysR-type regulator OxyS responds to oxidative stress and negatively regulates expression of the catalase-peroxidase gene. PLoS One 2012; 7:e30186. [PMID: 22272299 PMCID: PMC3260234 DOI: 10.1371/journal.pone.0030186] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 12/15/2011] [Indexed: 11/18/2022] Open
Abstract
Protection against oxidative stress is one of the primary defense mechanisms contributing to the survival of Mycobacterium tuberculosis in the host. In this study, we provide evidence that OxyS, a LysR-type transcriptional regulator functions as an oxidative stress response regulator in mycobacteria. Overexpression of OxyS lowers expression of the catalase-peroxidase (KatG) gene in M. smegmatis. OxyS binds directly with the katG promoter region and a conserved, GC-rich T-N(11)-A motif for OxyS binding was successfully characterized in the core binding site. Interestingly, the DNA-binding activity of OxyS was inhibited by H(2)O(2), but not by dithiothreitol. Cys25, which is situated at the DNA-binding domain of OxyS, was found to have a regulatory role for the DNA-binding ability of OxyS in response to oxidative stress. In contrast, the other three cysteine residues in OxyS do not appear to have this function. Furthermore, the mycobacterial strain over-expressing OxyS had a higher sensitivity to H(2)O(2). Thus, OxyS responds to oxidative stress through a unique cysteine residue situated in its DNA-binding domain and negatively regulates expression of the katG gene. These findings uncover a specific regulatory mechanism for mycobacterial adaptation to oxidative stress.
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Affiliation(s)
- Yuqing Li
- National Key Laboratory of Agricultural Microbiology, Center for Proteomics Research, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zheng-Guo He
- National Key Laboratory of Agricultural Microbiology, Center for Proteomics Research, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- * E-mail:
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Prozorov AA, Zaichikova MV, Danilenko VN. Mycobacterium tuberculosis mutants with multidrug resistance: History of origin, genetic and molecular mechanisms of resistance, and emerging challenges. RUSS J GENET+ 2012. [DOI: 10.1134/s1022795411120118] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Trivedi A, Singh N, Bhat SA, Gupta P, Kumar A. Redox biology of tuberculosis pathogenesis. Adv Microb Physiol 2012; 60:263-324. [PMID: 22633061 DOI: 10.1016/b978-0-12-398264-3.00004-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mycobacterium tuberculosis (Mtb) is one of the most successful human pathogens. Mtb is persistently exposed to numerous oxidoreductive stresses during its pathogenic cycle of infection and transmission. The distinctive ability of Mtb, not only to survive the redox stress manifested by the host but also to use it for synchronizing the metabolic pathways and expression of virulence factors, is central to its success as a pathogen. This review describes the paradigmatic redox and hypoxia sensors employed by Mtb to continuously monitor variations in the intracellular redox state and the surrounding microenvironment. Two component proteins, namely, DosS and DosT, are employed by Mtb to sense changes in oxygen, nitric oxide, and carbon monoxide levels, while WhiB3 and anti-sigma factor RsrA are used to monitor changes in intracellular redox state. Using these and other unidentified redox sensors, Mtb orchestrates its metabolic pathways to survive in nutrient-deficient, acidic, oxidative, nitrosative, and hypoxic environments inside granulomas or infectious lesions. A number of these metabolic pathways are unique to mycobacteria and thus represent potential drug targets. In addition, Mtb employs versatile machinery of the mycothiol and thioredoxin systems to ensure a reductive intracellular environment for optimal functioning of its proteins even upon exposure to oxidative stress. Mtb also utilizes a battery of protective enzymes, such as superoxide dismutase (SOD), catalase (KatG), alkyl hydroperoxidase (AhpC), and peroxiredoxins, to neutralize the redox stress generated by the host immune system. This chapter reviews the current understanding of mechanisms employed by Mtb to sense and neutralize redox stress and their importance in TB pathogenesis and drug development.
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Brossier F. Mécanismes d’action et de résistance de l’isoniazide, un antituberculeux de première ligne. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.antinf.2011.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Voskuil MI, Bartek IL, Visconti K, Schoolnik GK. The response of mycobacterium tuberculosis to reactive oxygen and nitrogen species. Front Microbiol 2011; 2:105. [PMID: 21734908 PMCID: PMC3119406 DOI: 10.3389/fmicb.2011.00105] [Citation(s) in RCA: 216] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 04/27/2011] [Indexed: 02/06/2023] Open
Abstract
The bacteriostatic and bactericidal effects and the transcriptional response of Mycobacterium tuberculosis to representative oxidative and nitrosative stresses were investigated by growth and survival studies and whole genome expression analysis. The M. tuberculosis reaction to a range of hydrogen peroxide (H2O2) concentrations fell into three distinct categories: (1) low level exposure resulted in induction of a few highly sensitive H2O2-responsive genes, (2) intermediate exposure resulted in massive transcriptional changes without an effect on growth or survival, and (3) high exposure resulted in a muted transcriptional response and eventual death. M. tuberculosis appears highly resistant to DNA damage-dependent, mode-one killing caused by low millimolar levels of H2O2 and only succumbs to overwhelming levels of oxidative stress observed in mode-two killing. Nitric oxide (NO) exposure initiated much the same transcriptional response as H2O2. However, unlike H2O2 exposure, NO exposure induced dormancy-related genes and caused dose-dependent bacteriostatic activity without killing. Included in the large shared response to H2O2 and NO was the induction of genes encoding iron–sulfur cluster repair functions including iron acquisition. Stress regulons controlled by IdeR, Sigma H, Sigma E, and FurA comprised a large portion of the response to both stresses. Expression of several oxidative stress defense genes was constitutive, or increased moderately from an already elevated constitutive level, suggesting that bacilli are continually primed for oxidative stress defense.
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Affiliation(s)
- Martin I Voskuil
- Department of Microbiology, School of Medicine, University of Colorado Denver Aurora, CO, USA
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Ando H, Kitao T, Miyoshi-Akiyama T, Kato S, Mori T, Kirikae T. Downregulation of katG expression is associated with isoniazid resistance in Mycobacterium tuberculosis. Mol Microbiol 2011; 79:1615-28. [DOI: 10.1111/j.1365-2958.2011.07547.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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