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Hu Q, Zhang L, Yang R, Tang J, Dong G. Quaternary ammonium biocides promote conjugative transfer of antibiotic resistance gene in structure- and species-dependent manner. ENVIRONMENT INTERNATIONAL 2024; 189:108812. [PMID: 38878503 DOI: 10.1016/j.envint.2024.108812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 06/03/2024] [Accepted: 06/09/2024] [Indexed: 06/19/2024]
Abstract
The linkage between biocides and antibiotic resistance has been widely suggested in laboratories and various environments. However, the action mechanism of biocides on antibiotic resistance genes (ARGs) spread is still unclear. Thus, 6 quaternary ammonium biocides (QACs) with different bonded substituents or alkyl chain lengths were selected to assess their effects on the conjugation transfer of ARGs in this study. Two conjugation models with the same donor (E. coli DH5α (RP4)) into two receptors, E. coli MG1655 and pathogenic S. sonnei SE6-1, were constructed. All QACs were found to significantly promote intra- and inter-genus conjugative transfer of ARGs, and the frequency was highly impacted by their structure and receptors. At the same environmental exposure level (4 × 10-1 mg/L), didecyl dimethyl ammonium chloride (DDAC (C10)) promoted the most frequency of conjugative transfer, while benzathine chloride (BEC) promoted the least. With the same donor, the enhanced frequency of QACs of intra-transfer is higher than inter-transfer. Then, the acquisition mechanisms of two receptors were further determined using biochemical combined with transcriptome analysis. For the recipient E. coli, the promotion of the intragenus conjugative transfer may be associated with increased cell membrane permeability, reactive oxygen species (ROS) production and proton motive force (PMF)-induced enhancement of flagellar motility. Whereas, the increase of cell membrane permeability and decreased flagellar motility due to PMF disruption but encouraged biofilm formation, maybe the main reasons for promoting intergenus conjugative transfer in the recipient S. sonnei. As one pathogenic bacterium, S. sonnei was first found to acquire ARGs by biocide exposure.
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Affiliation(s)
- Qin Hu
- Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing 400045, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
| | - Lilan Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing 400045, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
| | - Rui Yang
- Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Jialin Tang
- Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Guoliang Dong
- Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing 400045, China
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Sun W, Sun J, Ding Q, Qi M, Zhou J, Shi Y, Liu J, Won M, Sun X, Bai X, Dong B, Kim JS, Wang L. Breaking Iron Homeostasis: Iron Capturing Nanocomposites for Combating Bacterial Biofilm. Angew Chem Int Ed Engl 2024; 63:e202319690. [PMID: 38320965 DOI: 10.1002/anie.202319690] [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: 12/19/2023] [Revised: 01/22/2024] [Accepted: 02/06/2024] [Indexed: 02/08/2024]
Abstract
Given the scarcity of novel antibiotics, the eradication of bacterial biofilm infections poses formidable challenges. Upon bacterial infection, the host restricts Fe ions, which are crucial for bacterial growth and maintenance. Having coevolved with the host, bacteria developed adaptive pathways like the hemin-uptake system to avoid iron deficiency. Inspired by this, we propose a novel strategy, termed iron nutritional immunity therapy (INIT), utilizing Ga-CT@P nanocomposites constructed with gallium, copper-doped tetrakis (4-carboxyphenyl) porphyrin (TCPP) metal-organic framework, and polyamine-amine polymer dots, to target bacterial iron intakes and starve them. Owing to the similarity between iron/hemin and gallium/TCPP, gallium-incorporated porphyrin potentially deceives bacteria into uptaking gallium ions and concurrently extracts iron ions from the surrounding bacteria milieu through the porphyrin ring. This strategy orchestrates a "give and take" approach for Ga3+/Fe3+ exchange. Simultaneously, polymer dots can impede bacterial iron metabolism and serve as real-time fluorescent iron-sensing probes to continuously monitor dynamic iron restriction status. INIT based on Ga-CT@P nanocomposites induced long-term iron starvation, which affected iron-sulfur cluster biogenesis and carbohydrate metabolism, ultimately facilitating biofilm eradication and tissue regeneration. Therefore, this study presents an innovative antibacterial strategy from a nutritional perspective that sheds light on refractory bacterial infection treatment and its future clinical application.
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Affiliation(s)
- Wenyue Sun
- Department of Oral Implantology, Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, 130012, China
| | - Jiao Sun
- Department of Cell Biology, Norman Bethune College of Medicine, Jilin University, Changchun, 130021, China
| | - Qihang Ding
- Department of Chemistry, Korea University, Seoul, 02841, Republic of, Korea
| | - Manlin Qi
- Department of Oral Implantology, Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
| | - Jing Zhou
- Department of Oral Implantology, Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
| | - Yujia Shi
- Department of Oral Implantology, Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
| | - Jia Liu
- Department of Oral Implantology, Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
| | - Miae Won
- Department of Chemistry, Korea University, Seoul, 02841, Republic of, Korea
- TheranoChem Incorporation, Seoul, 02856, Republic of, Korea
| | - Xiaolin Sun
- Department of Oral Implantology, Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
| | - Xue Bai
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, 130012, China
| | - Biao Dong
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, 130012, China
| | - Jong Seung Kim
- Department of Chemistry, Korea University, Seoul, 02841, Republic of, Korea
- TheranoChem Incorporation, Seoul, 02856, Republic of, Korea
| | - Lin Wang
- Department of Oral Implantology, Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
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Zhou X, Guo X, Han J, Wang M, Liu Z, Ren D, Zhao J, Li Z. Cytochrome b561 regulates iron metabolism by activating the Akt/mTOR pathway to promote Breast Cancer Cells proliferation. Exp Cell Res 2023; 431:113760. [PMID: 37634562 DOI: 10.1016/j.yexcr.2023.113760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 08/18/2023] [Accepted: 08/22/2023] [Indexed: 08/29/2023]
Abstract
Breast cancer (BC) is the leading cause of cancer-related mortality in women, necessitating the development of novel therapeutic targets. While cytochrome b561 (CYB561) expression is associated with poor prognosis in BC, the precise role of CYB561 in BC and its potential mechanisms remain unclear. In the present study, we found that CYB561 plays an essential role in BC growth. CYB561 expression was up-regulated in surgically resected cancerous tissues and in six BC cell lines. Lentivirus-mediated CYB561 knockdown in BC cells significantly reduced their proliferation, migration, and invasiveness. CYB561 participates in the regulation of iron metabolism in BC. CYB561 knockdown reduced total iron content, increased ferrous iron content, and down-regulated the expression of proteins associated with iron metabolism (transferrin receptor 1, divalent metal transporter 1, and ferritin heavy chain 1). Conversely, up-regulation of CYB561 through co-incubation with exogenous iron (ferric ammonium citrate) produced contrary outcomes. Additionally, CYB561 activated the protein kinase B/mammalian target of rapamycin (Akt/mTOR) signaling pathway in BC cells. Down-regulation of CYB561 expression inhibited the Akt/mTOR signaling pathway activity. The application of an mTOR agonist (MHY1485) rescued this negative effect, as well as the inhibitory effect of CYB561 knockdown on cell proliferation. Importantly, the dual mTOR inhibitor MLN0128 (50 nM, 48 h) down-regulated CYB561 expression and the iron metabolism-related proteins transferrin receptor, divalent metal transporter 1, and ferritin heavy chain 1, whereas the mTOR agonist MHY1485 rescued the down-regulation of CYB561 knockdown on iron metabolism-related proteins. We conclude that CYB561 promotes the proliferation of BC cells by regulating iron metabolism through the activation of the Akt/mTOR signaling pathway.
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Affiliation(s)
- Xiaofeng Zhou
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, 810001, China; Pathology Department, Affiliated Hospital of Qinghai University, Xining, 810001, China
| | - Xinjian Guo
- Pathology Department, Affiliated Hospital of Qinghai University, Xining, 810001, China
| | - Jingqi Han
- Pathology Department, Affiliated Hospital of Qinghai University, Xining, 810001, China
| | - Miaozhou Wang
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, 810001, China; Breast Disease Diagnosis and Treatment Center, Affiliated Hospital of Qinghai University, Xining, 810001, China
| | - Zhen Liu
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, 810001, China; Breast Disease Diagnosis and Treatment Center, Affiliated Hospital of Qinghai University, Xining, 810001, China
| | - Dengfeng Ren
- Breast Disease Diagnosis and Treatment Center, Affiliated Hospital of Qinghai University, Xining, 810001, China
| | - Jiuda Zhao
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, 810001, China; Breast Disease Diagnosis and Treatment Center, Affiliated Hospital of Qinghai University, Xining, 810001, China.
| | - Zhanquan Li
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, 810001, China; Department of Hematopathology, Affiliated Hospital of Qinghai University, Xining, 810001, China.
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Azmat M, Ghalandari B, Jessica J, Xu Y, Li X, Su W, Qiang Z, Deng S, Azmat T, Jiang L, Ding X. PepDRED: De Novo Peptide Design with Strong Binding Affinity for Target Protein. Anal Chem 2023; 95:12264-12272. [PMID: 37553082 DOI: 10.1021/acs.analchem.3c01057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
De novo design of peptides that bind specifically to functional proteins is beneficial for diagnostics and therapeutics. However, complex permutations and combinations of amino acids pose significant challenges to the rational design of peptides with desirable stability and affinity. Herein, we develop a computational-based evolution method, namely, peptidomimetics-driven recognition elements design (PepDRED), to derive hemoglobin-inspired peptidomimetics. PepDRED mimics the natural evolutionism pipeline to generate stable apovariant (AVs) structures for wild-type counterparts via automated point mutations and validates their efficiency through free binding energy analysis and per residue energy decomposition analysis. For application demonstration, we applied PepDRED to design de novo peptides to bind FhuA, a typical TonB-dependent transporter (TBDT). TBDTs are Gram-negative bacterial outer membrane proteins responsible for iron transport and vital for bacterial resistance. PepDRED generated a pool of AVs and proceeded to reach an optimized peptide, AV440, with a remarkable binding affinity of -21 kcal/mol. AV440 is ∼2.5-fold stronger than the existing FhuA inhibitor Microcin J25. Network energy analysis further unveils that incorporating methionine (M42) in the N-terminal region significantly enhances inter-residue contacts and binding affinity. PepDRED offers a prompt and efficient in silico approach to develop potent peptide candidates for target proteins.
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Affiliation(s)
- Mehmoona Azmat
- Department of Anesthesiology and Surgical Intensive Care Unit, Xinhua Hospital, School of Medicine and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200230, China
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Behafarid Ghalandari
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Jessica Jessica
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Yuechen Xu
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Xinle Li
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Wenqiong Su
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Zhang Qiang
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Shuxin Deng
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Tabina Azmat
- Department of Cyber Security, AIR University, PAF Complex, E-9, Islamabad 44000, Pakistan
| | - Lai Jiang
- Department of Anesthesiology and Surgical Intensive Care Unit, Xinhua Hospital, School of Medicine and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200230, China
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
| | - Xianting Ding
- Department of Anesthesiology and Surgical Intensive Care Unit, Xinhua Hospital, School of Medicine and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200230, China
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, Shanghai Jiao Tong University, Shanghai 200230, China
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5
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Rayner B, Verderosa AD, Ferro V, Blaskovich MAT. Siderophore conjugates to combat antibiotic-resistant bacteria. RSC Med Chem 2023; 14:800-822. [PMID: 37252105 PMCID: PMC10211321 DOI: 10.1039/d2md00465h] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 02/21/2023] [Indexed: 10/31/2023] Open
Abstract
Antimicrobial resistance (AMR) is a global threat to society due to the increasing emergence of multi-drug resistant bacteria that are not susceptible to our last line of defence antibiotics. Exacerbating this issue is a severe gap in antibiotic development, with no new clinically relevant classes of antibiotics developed in the last two decades. The combination of the rapidly increasing emergence of resistance and scarcity of new antibiotics in the clinical pipeline means there is an urgent need for new efficacious treatment strategies. One promising solution, known as the 'Trojan horse' approach, hijacks the iron transport system of bacteria to deliver antibiotics directly into cells - effectively tricking bacteria into killing themselves. This transport system uses natively produced siderophores, which are small molecules with a high affinity for iron. By linking antibiotics to siderophores, to make siderophore antibiotic conjugates, the activity of existing antibiotics can potentially be reinvigorated. The success of this strategy was recently exemplified with the clinical release of cefiderocol, a cephalosporin-siderophore conjugate with potent antibacterial activity against carbapenem-resistant and multi-drug resistant Gram-negative bacilli. This review discusses the recent advancements in siderophore antibiotic conjugates and the challenges associated with the design of these compounds that need to be overcome to deliver more efficacious therapeutics. Potential strategies have also been suggested for new generations of siderophore-antibiotics with enhanced activity.
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Affiliation(s)
- Beth Rayner
- Centre for Superbug Solutions, Institute for Molecular Bioscience, University of Queensland Brisbane Queensland Australia
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
| | - Anthony D Verderosa
- Centre for Superbug Solutions, Institute for Molecular Bioscience, University of Queensland Brisbane Queensland Australia
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
| | - Vito Ferro
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, University of Queensland Brisbane Queensland Australia
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland Australia
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Pita-Grisanti V, Chasser K, Sobol T, Cruz-Monserrate Z. Understanding the Potential and Risk of Bacterial Siderophores in Cancer. Front Oncol 2022; 12:867271. [PMID: 35785195 PMCID: PMC9248441 DOI: 10.3389/fonc.2022.867271] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/06/2022] [Indexed: 01/19/2023] Open
Abstract
Siderophores are iron chelating molecules produced by nearly all organisms, most notably by bacteria, to efficiently sequester the limited iron that is available in the environment. Siderophores are an essential component of mammalian iron homeostasis and the ongoing interspecies competition for iron. Bacteria produce a broad repertoire of siderophores with a canonical role in iron chelation and the capacity to perform versatile functions such as interacting with other microbes and the host immune system. Siderophores are a vast area of untapped potential in the field of cancer research because cancer cells demand increased iron concentrations to sustain rapid proliferation. Studies investigating siderophores as therapeutics in cancer generally focused on the role of a few siderophores as iron chelators; however, these studies are limited and some show conflicting results. Moreover, siderophores are biologically conserved, structurally diverse molecules that perform additional functions related to iron chelation. Siderophores also have a role in inflammation due to their iron acquisition and chelation properties. These diverse functions may contribute to both risks and benefits as therapeutic agents in cancer. The potential of siderophore-mediated iron and bacterial modulation to be used in the treatment of cancer warrants further investigation. This review discusses the wide range of bacterial siderophore functions and their utilization in cancer treatment to further expand their functional relevance in cancer detection and treatment.
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Affiliation(s)
- Valentina Pita-Grisanti
- The Ohio State University Interdisciplinary Nutrition Program, The Ohio State University, Columbus, OH, United States
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
| | - Kaylin Chasser
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
| | - Trevor Sobol
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
| | - Zobeida Cruz-Monserrate
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
- *Correspondence: Zobeida Cruz-Monserrate,
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Klahn P, Zscherp R, Jimidar CC. Advances in the Synthesis of Enterobactin, Artificial Analogues, and Enterobactin-Derived Antimicrobial Drug Conjugates and Imaging Tools for Infection Diagnosis. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/a-1783-0751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
AbstractIron is an essential growth factor for bacteria, but although highly abundant in nature, its bioavailability during infection in the human host or the environment is limited. Therefore, bacteria produce and secrete siderophores to ensure their supply of iron. The triscatecholate siderophore enterobactin and its glycosylated derivatives, the salmochelins, play a crucial role for iron acquisition in several bacteria. As these compounds can serve as carrier molecules for the design of antimicrobial siderophore drug conjugates as well as siderophore-derived tool compounds for the detection of infections with bacteria, their synthesis and the design of artificial analogues is of interest. In this review, we give an overview on the synthesis of enterobactin, biomimetic as well as totally artificial analogues, and related drug-conjugates covering up to 12/2021.1 Introduction2 Antibiotic Crisis and Sideromycins as Natural Templates for New Antimicrobial Drugs3 Biosynthesis of Enterobactin, Salmochelins, and Microcins4 Total Synthesis of Enterobactin and Salmochelins5 Chemoenzymatic Semi-synthesis of Salmochelins and Microcin E492m Derivatives6 Synthesis of Biomimetic Enterobactin Derivatives with Natural Tris-lactone Backbone7 Synthesis of Artificial Enterobactin Derivatives without Tris-lactone Backbone8 Conclusions
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Affiliation(s)
- Philipp Klahn
- Institute of Organic Chemistry, Technische Universität Braunschweig
- Department for Chemistry and Molecular Biology, University of Gothenburg
| | - Robert Zscherp
- Institute of Organic Chemistry, Technische Universität Braunschweig
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Moreno-Pérez A, Ramos C, Rodríguez-Moreno L. HrpL Regulon of Bacterial Pathogen of Woody Host Pseudomonas savastanoi pv. savastanoi NCPPB 3335. Microorganisms 2021; 9:microorganisms9071447. [PMID: 34361883 PMCID: PMC8303149 DOI: 10.3390/microorganisms9071447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/17/2022] Open
Abstract
The Pseudomonas savastanoi species comprises a group of phytopathogenic bacteria that cause symptoms of disease in woody hosts. This is mediated by the rapid activation of a pool of virulence factors that suppress host defences and hijack the host’s metabolism to the pathogen’s benefit. The hrpL gene encodes an essential transcriptional regulator of virulence functions, including the type III secretion system (T3SS), in pathogenic bacteria. Here, we analyzed the contribution of HrpL to the virulence of four pathovars (pv.) of P. savastanoi isolated from different woody hosts (oleander, ash, broom, and dipladenia) and characterized the HrpL regulon of P. savastanoi pv. savastanoi NCPPB 3335 using two approaches: whole transcriptome sequencing (RNA-seq) and the bioinformatic prediction of candidate genes containing an hrp-box. Pathogenicity tests carried out for the P. savastanoi pvs. showed that HrpL was essential for symptom development in both non-host and host plants. The RNA-seq analysis of the HrpL regulon in P. savastanoi revealed a total of 53 deregulated genes, 49 of which were downregulated in the ΔhrpL mutant. Bioinformatic prediction resulted in the identification of 50 putative genes containing an hrp-box, 16 of which were shared with genes previously identified by RNA-seq. Although most of the genes regulated by HrpL belonged to the T3SS, we also identified some genes regulated by HrpL that could encode potential virulence factors in P. savastanoi.
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Affiliation(s)
- Alba Moreno-Pérez
- Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, Universidad de Málaga, E-29010 Málaga, Spain;
- Departamento de Microbiología y Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea «La Mayora», Extensión Campus de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), E-29010 Málaga, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, Universidad de Málaga, E-29010 Málaga, Spain;
- Departamento de Microbiología y Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea «La Mayora», Extensión Campus de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), E-29010 Málaga, Spain
- Correspondence: (C.R.); (L.R.-M.); Tel.: +34-952-132-146 (C.R.); +34-952-132-131 (L.R.-M.)
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, Universidad de Málaga, E-29010 Málaga, Spain;
- Departamento de Microbiología y Protección de Cultivos, Instituto de Hortofruticultura Subtropical y Mediterránea «La Mayora», Extensión Campus de Teatinos, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), E-29010 Málaga, Spain
- Correspondence: (C.R.); (L.R.-M.); Tel.: +34-952-132-146 (C.R.); +34-952-132-131 (L.R.-M.)
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9
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Zscherp R, Coetzee J, Vornweg J, Grunenberg J, Herrmann J, Müller R, Klahn P. Biomimetic enterobactin analogue mediates iron-uptake and cargo transport into E. coli and P. aeruginosa. Chem Sci 2021; 12:10179-10190. [PMID: 34377407 PMCID: PMC8336463 DOI: 10.1039/d1sc02084f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/16/2021] [Indexed: 11/21/2022] Open
Abstract
The design, synthesis and biological evaluation of the artificial enterobactin analogue EntKL and several fluorophore-conjugates thereof are described. EntKL provides an attachment point for cargos such as fluorophores or antimicrobial payloads. Corresponding conjugates are recognized by outer membrane siderophore receptors of Gram-negative pathogens and retain the natural hydrolyzability of the tris-lactone backbone. Initial density-functional theory (DFT) calculations of the free energies of solvation (ΔG(sol)) and relaxed Fe–O force constants of the corresponding [Fe-EntKL]3− complexes indicated a similar iron binding constant compared to natural enterobactin (Ent). The synthesis of EntKL was achieved via an iterative assembly based on a 3-hydroxylysine building block over 14 steps with an overall yield of 3%. A series of growth recovery assays under iron-limiting conditions with Escherichia coli and Pseudomonas aeruginosa mutant strains that are defective in natural siderophore synthesis revealed a potent concentration-dependent growth promoting effect of EntKL similar to natural Ent. Additionally, four cargo-conjugates differing in molecular size were able to restore growth of E. coli indicating an uptake into the cytosol. P. aeruginosa displayed a stronger uptake promiscuity as six different cargo-conjugates were found to restore growth under iron-limiting conditions. Imaging studies utilizing BODIPYFL-conjugates, demonstrated the ability of EntKL to overcome the Gram-negative outer membrane permeability barrier and thus deliver molecular cargos via the bacterial iron transport machinery of E. coli and P. aeruginosa. The design, synthesis and evaluation of the enterobactin derivative (AcO)EntKL is reported, which mediates iron uptake and cargo transport into E. coli and P. aeruginosa and was able to compete with human enterobactin and iron binding proteins.![]()
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Affiliation(s)
- Robert Zscherp
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
| | - Janetta Coetzee
- Department for Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Department of Pharmacy at Universität des Saarlandes Campus Building E 8.1 D-66123 Saarbrücken Germany.,German Center for Infection Research (DZIF) Site Hannover-Braunschweig Germany
| | - Johannes Vornweg
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
| | - Jörg Grunenberg
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
| | - Jennifer Herrmann
- Department for Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Department of Pharmacy at Universität des Saarlandes Campus Building E 8.1 D-66123 Saarbrücken Germany.,German Center for Infection Research (DZIF) Site Hannover-Braunschweig Germany
| | - Rolf Müller
- Department for Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Department of Pharmacy at Universität des Saarlandes Campus Building E 8.1 D-66123 Saarbrücken Germany.,German Center for Infection Research (DZIF) Site Hannover-Braunschweig Germany
| | - Philipp Klahn
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
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10
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Dai J, Chen Z, Hou J, Wang Y, Guo M, Cao J, Wang L, Xu H, Tian B, Zhao Y. MazEF Toxin-Antitoxin System-Mediated DNA Damage Stress Response in Deinococcus radiodurans. Front Genet 2021; 12:632423. [PMID: 33679894 PMCID: PMC7933679 DOI: 10.3389/fgene.2021.632423] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/12/2021] [Indexed: 01/01/2023] Open
Abstract
Deinococcus radiodurans shows marked resistance to various types of DNA-damaging agents, including mitomycin C (MMC). A type II toxin-antitoxin (TA) system that responds to DNA damage stress was identified in D. radiodurans, comprising the toxin MazF-dr and the antitoxin MazE-dr. The cleavage specificity of MazF-dr, an endoribonuclease, was previously characterized. Here, we further investigated the regulatory role of the MazEF system in the response to DNA damage stress in D. radiodurans. The crystal structure of D. radiodurans MazF (MazF-dr) was determined at a resolution of 1.3 Å and is the first structure of the toxin of the TA system of D. radiodurans. MazF-dr forms a dimer mediated by the presence of interlocked loops. Transcriptional analysis revealed 650 downregulated genes in the wild-type (WT) strain, but not in the mazEF mutant strain, which are potentially regulated by MazEF-dr in response to MMC treatment. Some of these genes are involved in membrane trafficking and metal ion transportation. Subsequently, compared with the WT strain, the mazEF mutant strain exhibited much lower MMC-induced intracellular iron concentrations, reactive oxygen species (ROS), and protein carbonylation levels. These results provide evidence that MazEF-mediated cell death in D. radiodurans might be caused by an increase in ROS accumulation upon DNA damage stress.
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Affiliation(s)
- Jingli Dai
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Zijing Chen
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Jinfeng Hou
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Yudong Wang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Miao Guo
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Jiajia Cao
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Liangyan Wang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Hong Xu
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Bing Tian
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Ye Zhao
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
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11
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Trindade IB, Hernandez G, Lebègue E, Barrière F, Cordeiro T, Piccioli M, Louro RO. Conjuring up a ghost: structural and functional characterization of FhuF, a ferric siderophore reductase from E. coli. J Biol Inorg Chem 2021; 26:313-326. [PMID: 33559753 PMCID: PMC8068687 DOI: 10.1007/s00775-021-01854-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 01/23/2021] [Indexed: 10/27/2022]
Abstract
Iron is a fundamental element for virtually all forms of life. Despite its abundance, its bioavailability is limited, and thus, microbes developed siderophores, small molecules, which are synthesized inside the cell and then released outside for iron scavenging. Once inside the cell, iron removal does not occur spontaneously, instead this process is mediated by siderophore-interacting proteins (SIP) and/or by ferric-siderophore reductases (FSR). In the past two decades, representatives of the SIP subfamily have been structurally and biochemically characterized; however, the same was not achieved for the FSR subfamily. Here, we initiate the structural and functional characterization of FhuF, the first and only FSR ever isolated. FhuF is a globular monomeric protein mainly composed by α-helices sheltering internal cavities in a fold resembling the "palm" domain found in siderophore biosynthetic enzymes. Paramagnetic NMR spectroscopy revealed that the core of the cluster has electronic properties in line with those of previously characterized 2Fe-2S ferredoxins and differences appear to be confined to the coordination of Fe(III) in the reduced protein. In particular, the two cysteines coordinating this iron appear to have substantially different bond strengths. In similarity with the proteins from the SIP subfamily, FhuF binds both the iron-loaded and the apo forms of ferrichrome in the micromolar range and cyclic voltammetry reveals the presence of redox-Bohr effect, which broadens the range of ferric-siderophore substrates that can be thermodynamically accessible for reduction. This study suggests that despite the structural differences between FSR and SIP proteins, mechanistic similarities exist between the two classes of proteins.
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Affiliation(s)
- I B Trindade
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB‑NOVA), Universidade Nova de Lisboa, Av. da República (EAN), 2780‑157, Oeiras, Portugal
| | - G Hernandez
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB‑NOVA), Universidade Nova de Lisboa, Av. da República (EAN), 2780‑157, Oeiras, Portugal
| | - E Lebègue
- Université de Nantes, CNRS, CEISAM UMR 6230, 44000, Nantes, France
| | - F Barrière
- Institut des Sciences Chimiques de Rennes-UMR 6226, Université Rennes, CNRS, 35000, Rennes, France
| | - T Cordeiro
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB‑NOVA), Universidade Nova de Lisboa, Av. da República (EAN), 2780‑157, Oeiras, Portugal
| | - M Piccioli
- Department of Chemistry, Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019, Sesto Fiorentino, Italy.,Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (CIRMMP), Via L. Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - R O Louro
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB‑NOVA), Universidade Nova de Lisboa, Av. da República (EAN), 2780‑157, Oeiras, Portugal.
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12
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Fan D, Fang Q. Siderophores for medical applications: Imaging, sensors, and therapeutics. Int J Pharm 2021; 597:120306. [PMID: 33540031 DOI: 10.1016/j.ijpharm.2021.120306] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 01/07/2023]
Abstract
Siderophores are low-molecular-weight chelators produced by microorganisms to scavenge iron from the environment and deliver it to cells via specific receptors. Tremendous researches on the molecular basis of siderophore regulation, synthesis, secretion, and uptake have inspired their diverse applications in the medical field. Replacing iron with radionuclides in siderophores, such as the most prominent Ga-68 for positron emission tomography (PET), carves out ways for targeted imaging of infectious diseases and cancers. Additionally, the high affinity of siderophores for metal ions or microorganisms makes them a potent detecting moiety in sensors that can be used for diagnosis. As for therapeutics, the notable Trojan horse-inspired siderophore-antibiotic conjugates demonstrate enhanced toxicity against multi-drug resistant (MDR) pathogens. Besides, siderophores can tackle iron overload diseases and, when combined with moieties such as hydrogels and nanoparticles, a wide spectrum of iron-induced diseases and even cancers. In this review, we briefly outline the related mechanisms, before summarizing the siderophore-based applications in imaging, sensors, and therapeutics.
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Affiliation(s)
- Di Fan
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China
| | - Qiaojun Fang
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China; Sino-Danish Center for Education and Research, Beijing 101408, PR China.
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13
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Sy BM, Tree JJ. Small RNA Regulation of Virulence in Pathogenic Escherichia coli. Front Cell Infect Microbiol 2021; 10:622202. [PMID: 33585289 PMCID: PMC7873438 DOI: 10.3389/fcimb.2020.622202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/10/2020] [Indexed: 11/17/2022] Open
Abstract
Enteric and extraintestinal pathotypes of Escherichia coli utilize a wide range of virulence factors to colonize niches within the human body. During infection, virulence factors such as adhesins, secretions systems, or toxins require precise regulation and coordination to ensure appropriate expression. Additionally, the bacteria navigate rapidly changing environments with fluctuations in pH, temperature, and nutrient levels. Enteric pathogens utilize sophisticated, interleaved systems of transcriptional and post-transcriptional regulation to sense and respond to these changes and modulate virulence gene expression. Regulatory small RNAs and RNA-binding proteins play critical roles in the post-transcriptional regulation of virulence. In this review we discuss how the mosaic genomes of Escherichia coli pathotypes utilize small RNA regulation to adapt to their niche and become successful human pathogens.
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Affiliation(s)
- Brandon M Sy
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
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14
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de Alwis R, Liang L, Taghavian O, Werner E, The HC, Thu TNH, Duong VT, Davies DH, Felgner PL, Baker S. The identification of novel immunogenic antigens as potential Shigella vaccine components. Genome Med 2021; 13:8. [PMID: 33451348 PMCID: PMC7809897 DOI: 10.1186/s13073-020-00824-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/18/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Shigella is a major diarrheal pathogen for which there is presently no vaccine. Whole genome sequencing provides the ability to predict and derive novel antigens for use as vaccines. Here, we aimed to identify novel immunogenic Shigella antigens that could serve as Shigella vaccine candidates, either alone, or when conjugated to Shigella O-antigen. METHODS Using a reverse vaccinology approach, where genomic analysis informed the Shigella immunome via an antigen microarray, we aimed to identify novel immunogenic Shigella antigens. A core genome analysis of Shigella species, pathogenic and non-pathogenic Escherichia coli, led to the selection of 234 predicted immunogenic Shigella antigens. These antigens were expressed and probed with acute and convalescent serum from microbiologically confirmed Shigella infections. RESULTS Several Shigella antigens displayed IgG and IgA seroconversion, with no difference in sero-reactivity across by sex or age. IgG sero-reactivity to key Shigella antigens was observed at birth, indicating transplacental antibody transfer. Six antigens (FepA, EmrK, FhuA, MdtA, NlpB, and CjrA) were identified in in vivo testing as capable of producing binding IgG and complement-mediated bactericidal antibody. CONCLUSIONS These findings provide six novel immunogenic Shigella proteins that could serve as candidate vaccine antigens, species-specific carrier proteins, or targeted adjuvants.
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Affiliation(s)
- Ruklanthi de Alwis
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
- Viral Research and Experimental Medicine Centre, SingHealth Duke-NUS Academic Medical Centre, Singapore, Singapore
| | - Li Liang
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Omid Taghavian
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Emma Werner
- Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Hao Chung The
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Trang Nguyen Hoang Thu
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vu Thuy Duong
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - D Huw Davies
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Philip L Felgner
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Level 5, Jeffery Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK.
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15
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Khan A, Singh P, Srivastava A. Iron: Key player in cancer and cell cycle? J Trace Elem Med Biol 2020; 62:126582. [PMID: 32673942 DOI: 10.1016/j.jtemb.2020.126582] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 12/31/2019] [Accepted: 06/09/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Iron is an essential element for growth and metabolic activities of all living organisms but remains in its oxyhydroxide ferric ion form in the surrounding. Unavailability of iron in soluble ferrous form led to development of specific pathways and machinery in different organisms to make it available for use and maintain its homeostasis. Iron homeostasis is essential as under different circumstances iron in excess as well as deprivation leads to different pathological conditions in human. OBJECTIVE This review highlights the current findings related to iron excess as well as deprivation with regards to cellular proliferation. CONCLUSIONS Iron excess is extensively associated with different types of cancers viz. colorectal cancer, breast cancer etc. by producing an oxidative stressed condition and alteration of immune system. Ironically its deprivation also results in anaemic conditions and leads to cell cycle arrest at different phases with mechanism yet to be explored. Iron deprivation arrests cell cycle at G1/S and in some cases at G2/M checkpoints resulting in growth arrest. However, in some cases iron overload arrests cell cycle at G1 phase by blocking certain signalling pathways. Certain natural and synthetic iron chelators are being explored from few decades to combat diseases caused by alteration in iron homeostasis.
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Affiliation(s)
- Azmi Khan
- Department of Life Science, School of Earth, Biological and Environmental Sciences, Central University of South Bihar, Gaya, Bihar, India
| | - Pratika Singh
- Department of Life Science, School of Earth, Biological and Environmental Sciences, Central University of South Bihar, Gaya, Bihar, India
| | - Amrita Srivastava
- Department of Life Science, School of Earth, Biological and Environmental Sciences, Central University of South Bihar, Gaya, Bihar, India.
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16
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Zhang Y, Ren J, Wang W, Chen B, Li E, Chen S. Siderophore and indolic acid production by Paenibacillus triticisoli BJ-18 and their plant growth-promoting and antimicrobe abilities. PeerJ 2020; 8:e9403. [PMID: 32742769 PMCID: PMC7367057 DOI: 10.7717/peerj.9403] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 06/01/2020] [Indexed: 12/22/2022] Open
Abstract
Paenibacillus triticisoli BJ-18, a N2-fixing bacterium, is able to promote plant growth, but the secondary metabolites that may play a role in promoting plant growth have never been characterized. In this study, untargeted metabolomics profiling of P. triticisoli BJ-18 indicated the existence of 101 known compounds, including N2-acetyl ornithine, which is the precursor of siderophores, plant growth regulators such as trehalose 6-phosphate, betaine and trigonelline, and other bioactive molecules such as oxymatrine, diosmetin, luotonin A, (-)-caryophyllene oxide and tetrahydrocurcumin. In addition, six compounds were also isolated from P. triticisoli BJ-18 using a combination of silica gel chromatography, sephadex LH-20, octadecyl silane (ODS), and high-performance liquid chromatography (HPLC). The compound structures were further analyzed by Nuclear Magnetic Resonance (NMR), Mass Spectrometry (MS), and Electronic Circular Dichroism (ECD). The six compounds included three classical siderophore fusarinines identified as deshydroxylferritriacetylfusigen, desferritriacetylfusigen, and triacetylfusigen, and three indolic acids identified as paenibacillic acid A, 3-indoleacetic acid (IAA), and 3-indolepropionic acid (IPA). Both deshydroxylferritriacetylfusigen and paenibacillic acid A have new structures. Fusarinines, which normally occur in fungi, were isolated from bacterium for the first time in this study. Both siderophores (compounds 1 and 2) showed antimicrobial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis, but did not show obvious inhibitory activity against yeast Candida albicans, whereas triacetylfusigen (compound 3) showed no antibiosis activity against these test microorganisms. Paenibacillic acid A, IAA, and IPA were shown to promote the growth of plant shoots and roots, and paenibacillic acid A also showed antimicrobial activity against S. aureus. Our study demonstrates that siderophores and indolic acids may play an important role in plant growth promotion by P. triticisoli BJ-18.
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Affiliation(s)
- Yunzhi Zhang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People’s Republic of China
| | - Jinwei Ren
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Wenzhao Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Baosong Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Erwei Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Sanfeng Chen
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People’s Republic of China
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17
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Nguyen LP, Pinto NA, Vu TN, Lee H, Cho YL, Byun JH, D’Souza R, Yong D. In Vitro Activity of a Novel Siderophore-Cephalosporin, GT-1 and Serine-Type β-Lactamase Inhibitor, GT-055, against Escherichia coli, Klebsiella pneumoniae and Acinetobacter spp. Panel Strains. Antibiotics (Basel) 2020; 9:antibiotics9050267. [PMID: 32443875 PMCID: PMC7277296 DOI: 10.3390/antibiotics9050267] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/13/2020] [Accepted: 05/19/2020] [Indexed: 11/16/2022] Open
Abstract
This study investigates GT-1 (also known as LCB10-0200), a novel-siderophore cephalosporin, inhibited multidrug-resistant (MDR) Gram-negative pathogen, via a Trojan horse strategy exploiting iron-uptake systems. We investigated GT-1 activity and the role of siderophore uptake systems, and the combination of GT-1 and a non-β-lactam β-lactamase inhibitor (BLI) of diazabicyclooctane, GT-055, (also referred to as LCB18-055) against molecularly characterised resistant Escherichia coli, Klebsiella pneumoniae and Acinetobacter spp. isolates. GT-1 and GT-1/GT-055 were tested in vitro against comparators among three different characterised panel strain sets. Bacterial resistome and siderophore uptake systems were characterised to elucidate the genetic basis for GT-1 minimum inhibitory concentrations (MICs). GT-1 exhibited in vitro activity (≤2 μg/mL MICs) against many MDR isolates, including extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing E. coli and K. pneumoniae and oxacillinase (OXA)-producing Acinetobacter spp. GT-1 also inhibited strains with mutated siderophore transporters and porins. Although BLI GT-055 exhibited intrinsic activity (MIC 2-8 μg/mL) against most E. coli and K. pneumoniae isolates, GT-055 enhanced the activity of GT-1 against many GT-1-resistant strains. Compared with CAZ-AVI, GT-1/GT-055 exhibited lower MICs against E. coli and K. pneumoniae isolates. GT-1 demonstrated potent in vitro activity against clinical panel strains of E. coli, K. pneumoniae and Acinetobacter spp. GT-055 enhanced the in vitro activity of GT-1 against many GT-1-resistant strains.
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Affiliation(s)
- Le Phuong Nguyen
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, College of Medicine, Yonsei University, Seoul 03722, Korea; (L.P.N.); (N.A.P.); (T.N.V.); (H.L.)
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 03722, Korea
| | - Naina Adren Pinto
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, College of Medicine, Yonsei University, Seoul 03722, Korea; (L.P.N.); (N.A.P.); (T.N.V.); (H.L.)
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 03722, Korea
| | - Thao Nguyen Vu
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, College of Medicine, Yonsei University, Seoul 03722, Korea; (L.P.N.); (N.A.P.); (T.N.V.); (H.L.)
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 03722, Korea
| | - Hyunsook Lee
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, College of Medicine, Yonsei University, Seoul 03722, Korea; (L.P.N.); (N.A.P.); (T.N.V.); (H.L.)
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 03722, Korea
| | | | - Jung-Hyun Byun
- Department of Laboratory Medicine, Gyeongsang National University College of Medicine, Gyeongsang National University Hospital, Jinju 52727, Korea;
| | - Roshan D’Souza
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, College of Medicine, Yonsei University, Seoul 03722, Korea; (L.P.N.); (N.A.P.); (T.N.V.); (H.L.)
- J. Craig Venter Institute, Rockville, MD 20850, USA
- Correspondence: (R.D.); (D.Y.); Tel.: +1-301-795-7342 (R.D.); +82-2-2228-2442 (D.Y.); Fax: +82-2-364-1583 (D.Y.)
| | - Dongeun Yong
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, College of Medicine, Yonsei University, Seoul 03722, Korea; (L.P.N.); (N.A.P.); (T.N.V.); (H.L.)
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 03722, Korea
- Correspondence: (R.D.); (D.Y.); Tel.: +1-301-795-7342 (R.D.); +82-2-2228-2442 (D.Y.); Fax: +82-2-364-1583 (D.Y.)
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18
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Ferric Citrate Regulator FecR Is Translocated across the Bacterial Inner Membrane via a Unique Twin-Arginine Transport-Dependent Mechanism. J Bacteriol 2020; 202:JB.00541-19. [PMID: 32015149 PMCID: PMC7148137 DOI: 10.1128/jb.00541-19] [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] [Received: 08/21/2019] [Accepted: 12/19/2019] [Indexed: 02/07/2023] Open
Abstract
In Escherichia coli, citrate-mediated iron transport is a key nonheme pathway for the acquisition of iron. Binding of ferric citrate to the outer membrane protein FecA induces a signal cascade that ultimately activates the cytoplasmic sigma factor FecI, resulting in transcription of the fecABCDE ferric citrate transport genes. Central to this process is signal transduction mediated by the inner membrane protein FecR. FecR spans the inner membrane through a single transmembrane helix, which is flanked by cytoplasm- and periplasm-orientated moieties at the N and C termini. The transmembrane helix of FecR resembles a twin-arginine signal sequence, and the substitution of the paired arginine residues of the consensus motif decouples the FecR-FecI signal cascade, rendering the cells unable to activate transcription of the fec operon when grown on ferric citrate. Furthermore, the fusion of beta-lactamase C-terminal to the FecR transmembrane helix results in translocation of the C-terminal domain that is dependent on the twin-arginine translocation (Tat) system. Our findings demonstrate that FecR belongs to a select group of bitopic inner membrane proteins that contain an internal twin-arginine signal sequence.IMPORTANCE Iron is essential for nearly all living organisms due to its role in metabolic processes and as a cofactor for many enzymes. The FecRI signal transduction pathway regulates citrate-mediated iron import in many Gram-negative bacteria, including Escherichia coli The interactions of FecR with the outer membrane protein FecA and cytoplasmic anti-sigma factor FecI have been extensively studied. However, the mechanism by which FecR inserts into the membrane has not previously been reported. In this study, we demonstrate that the targeting of FecR to the cytoplasmic membrane is dependent on the Tat system. As such, FecR represents a new class of bitopic Tat-dependent membrane proteins with an internal twin-arginine signal sequence.
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19
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Samantarrai D, Lakshman Sagar A, Gudla R, Siddavattam D. TonB-Dependent Transporters in Sphingomonads: Unraveling Their Distribution and Function in Environmental Adaptation. Microorganisms 2020; 8:microorganisms8030359. [PMID: 32138166 PMCID: PMC7142613 DOI: 10.3390/microorganisms8030359] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/24/2019] [Accepted: 01/07/2020] [Indexed: 12/19/2022] Open
Abstract
TonB-dependent transport system plays a critical role in the transport of nutrients across the energy-deprived outer membrane of Gram-negative bacteria. It contains a specialized outer membrane TonB-dependent transporter (TBDT) and energy generating (ExbB/ExbD) and transducing (TonB) inner membrane multi-protein complex, called TonB complex. Very few TonB complex protein-coding sequences exist in the genomes of Gram-negative bacteria. Interestingly, the TBDT coding alleles are phenomenally high, especially in the genomes of bacteria surviving in complex and stressful environments. Sphingomonads are known to survive in highly polluted environments using rare, recalcitrant, and toxic substances as their sole source of carbon. Naturally, they also contain a huge number of TBDTs in the outer membrane. Out of them, only a few align with the well-characterized TBDTs. The functions of the remaining TBDTs are not known. Predictions made based on genome context and expression pattern suggest their involvement in the transport of xenobiotic compounds across the outer membrane.
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Abstract
Diatoms can access inorganic iron with remarkable efficiency, but this process is contingent on carbonate ion concentration. As ocean acidification reduces carbonate concentration, inorganic iron uptake may be discouraged in favor of carbonate-independent uptake. We report details of an iron assimilation process that needs no carbonate but requires exogenous compounds produced by cooccurring organisms. We show this process to be critical for diatom growth at high siderophore concentrations, but ineffective at acquiring iron from low-affinity organic chelators or lithogenic particulates. Understanding the caveats associated with iron source preference in diatoms will help predict the impacts of climate change on microbial community structure in high-nitrate low-chlorophyll ecosystems. Iron uptake by diatoms is a biochemical process with global biogeochemical implications. In large regions of the surface ocean diatoms are both responsible for the majority of primary production and frequently experiencing iron limitation of growth. The strategies used by these phytoplankton to extract iron from seawater constrain carbon flux into higher trophic levels and sequestration into sediments. In this study we use reverse genetic techniques to target putative iron-acquisition genes in the model pennate diatom Phaeodactylum tricornutum. We describe components of a reduction-dependent siderophore acquisition pathway that relies on a bacterial-derived receptor protein and provides a viable alternative to inorganic iron uptake under certain conditions. This form of iron uptake entails a close association between diatoms and siderophore-producing organisms during low-iron conditions. Homologs of these proteins are found distributed across diatom lineages, suggesting the significance of siderophore utilization by diatoms in the marine environment. Evaluation of specific proteins enables us to confirm independent iron-acquisition pathways in diatoms and characterize their preferred substrates. These findings refine our mechanistic understanding of the multiple iron-uptake systems used by diatoms and help us better predict the influence of iron speciation on taxa-specific iron bioavailability.
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Negash KH, Norris JKS, Hodgkinson JT. Siderophore-Antibiotic Conjugate Design: New Drugs for Bad Bugs? Molecules 2019; 24:molecules24183314. [PMID: 31514464 PMCID: PMC6767078 DOI: 10.3390/molecules24183314] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/18/2022] Open
Abstract
Antibiotic resistance is a global health concern and a current threat to modern medicine and society. New strategies for antibiotic drug design and delivery offer a glimmer of hope in a currently limited pipeline of new antibiotics. One strategy involves conjugating iron-chelating microbial siderophores to an antibiotic or antimicrobial agent to enhance uptake and antibacterial potency. Cefiderocol (S-649266) is a promising cephalosporin–catechol conjugate currently in phase III clinical trials that utilizes iron-mediated active transport and demonstrates enhanced potency against multi-drug resistant (MDR) Gram-negative pathogens. Such molecules demonstrate that siderophore–antibiotic conjugates could be important future medicines to add to our antibiotic arsenal. This review is written in the context of the chemical design of siderophore–antibiotic conjugates focusing on the differing siderophore, linker, and antibiotic components that make up conjugates. We selected chemically distinct siderophore–antibiotic conjugates as exemplary conjugates, rather than multiple analogues, to highlight findings to date. The review should offer a general guide to the uninitiated in the molecular design of siderophore–antibiotic conjugates.
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Affiliation(s)
- Kokob H Negash
- Leicester Institute of Structural and Chemical Biology, School of Chemistry, University of Leicester, George Porter Building, University Road, Leicester LE1 7RH, UK
| | - James K S Norris
- Leicester Institute of Structural and Chemical Biology, School of Chemistry, University of Leicester, George Porter Building, University Road, Leicester LE1 7RH, UK
| | - James T Hodgkinson
- Leicester Institute of Structural and Chemical Biology, School of Chemistry, University of Leicester, George Porter Building, University Road, Leicester LE1 7RH, UK.
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22
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Knight LC, Wang M, Donovan SM, Dilger RN. Early-Life Iron Deficiency and Subsequent Repletion Alters Development of the Colonic Microbiota in the Pig. Front Nutr 2019; 6:120. [PMID: 31440513 PMCID: PMC6692694 DOI: 10.3389/fnut.2019.00120] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/19/2019] [Indexed: 12/26/2022] Open
Abstract
Background: Iron deficiency is the most prevalent micronutrient deficiency worldwide, affecting over two billion people. Early-life iron deficiency may alter the developing microbiota, which may or may not be reversible with subsequent dietary iron repletion. Thus, the aim of this study was to determine whether early-life iron deficiency and subsequent repletion alter colonic microbial composition and fermentation end-product concentrations in pigs. Methods: Forty-two male pigs received either control (CONT, 21.3 mg Fe/L) or iron-deficient (ID, 2.72 mg Fe/L) milk replacer treatments from postnatal day (PND) 2 to 32. Subsequently, 20 pigs continued through a series of age-appropriate, iron-adequate diets from PND 33 to 61. Contents from the ascending colon (AC) and rectum (feces) were collected at PND 32 and/or 61. Assessments included microbiota composition by 16S rRNA sequencing and volatile fatty acid (VFA) concentrations by gas chromatography methods. Data were analyzed using a 1-way ANOVA and PERMANOVA to assess the main effects of early-life iron status on all outcomes. Results: In AC samples, 15 genera differed (P < 0.05) between ID and CONT pigs, while 27 genera differed (P < 0.05) in fecal samples at PND 32. Early-life ID pigs had higher (P = 0.012) relative abundance of Lactobacillus in AC samples compared with CONT pigs. In feces, ID pigs had lower (P < 0.05) relative abundances of Bacteroides and Clostridium from the families of Clostridiaceae, Lachnospiraceae, and Ruminococcaceae. At PND 61, only two genera differed between treatment groups in AC samples, with ID pigs having a higher (P = 0.043) relative abundance of Bifidobacterium and lower (P = 0.047) relative abundance of Prevotella. Beta diversity differed at PND 32 in both AC and feces between CONT and ID pigs but no differences remained at PND 61. At PND 32, the total VFA concentration was higher in ID pigs compared with CONT pigs in both AC (P = 0.003) and feces (P = 0.001), but no differences in VFA concentrations persisted to PND 61. Conclusion: Early-life iron status influenced microbial composition and VFA concentrations within the large intestine, but these differences were largely normalized following subsequent dietary iron repletion.
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Affiliation(s)
- Laura C. Knight
- Piglet Nutrition & Cognition Laboratory, Department of Animal Sciences, University of Illinois, Urbana, IL, United States
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States
| | - Mei Wang
- Department of Food Science and Human Nutrition, University of Illinois, Urbana, IL, United States
| | - Sharon M. Donovan
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States
- Department of Food Science and Human Nutrition, University of Illinois, Urbana, IL, United States
| | - Ryan N. Dilger
- Piglet Nutrition & Cognition Laboratory, Department of Animal Sciences, University of Illinois, Urbana, IL, United States
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States
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23
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Sarowska J, Futoma-Koloch B, Jama-Kmiecik A, Frej-Madrzak M, Ksiazczyk M, Bugla-Ploskonska G, Choroszy-Krol I. Virulence factors, prevalence and potential transmission of extraintestinal pathogenic Escherichia coli isolated from different sources: recent reports. Gut Pathog 2019; 11:10. [PMID: 30828388 PMCID: PMC6383261 DOI: 10.1186/s13099-019-0290-0] [Citation(s) in RCA: 323] [Impact Index Per Article: 64.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/11/2019] [Indexed: 02/07/2023] Open
Abstract
Extraintestinal pathogenic E. coli (ExPEC) are facultative pathogens that are part of the normal human intestinal flora. The ExPEC group includes uropathogenic E. coli (UPEC), neonatal meningitis E. coli (NMEC), sepsis-associated E. coli (SEPEC), and avian pathogenic E. coli (APEC). Virulence factors (VF) related to the pathogenicity of ExPEC are numerous and have a wide range of activities, from those related to bacteria colonization to those related to virulence, including adhesins, toxins, iron acquisition factors, lipopolysaccharides, polysaccharide capsules, and invasins, which are usually encoded on pathogenicity islands (PAIs), plasmids and other mobile genetic elements. Mechanisms underlying the dynamics of ExPEC transmission and the selection of virulent clones are still poorly understood and require further research. The time shift between colonization of ExPEC and the development of infection remains problematic in the context of establishing the relation between consumption of contaminated food and the appearance of first disease symptoms. What appears to be most difficult is to prove that ExPEC strains cause disease symptoms and to examine the mechanism of transition from the asymptomatic colonization of the intestines to the spreading of the bacteria outside the digestive system. A significant problem for researchers who are trying to ascribe ExPEC transmission to food, people or the environment is to draw the distinction between colonization of ExPEC and infection. Food safety is an important challenge for public health both at the production stage and in the course of its processing and distribution. Examination of the genetic similarity of ExPEC strains will allow to determine their origin from different sources. Many levels of genotyping have been proposed in which the typing of strains, plasmids and genes is compared in order to obtain a more complete picture of this complex problem. The aim of our study was to characterize E. coli strains isolated from humans, animals and food for the presence of bacterial genes encoding virulence factors such as toxins, and iron acquisition systems (siderophores) in the context of an increasing spread of ExPEC infections.
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Affiliation(s)
- Jolanta Sarowska
- 1Department of Basic Sciences, Faculty of Health Sciences, Wroclaw Medical University, Chalubinskiego 4, 50-368 Wroclaw, Poland
| | - Bozena Futoma-Koloch
- 2Department of Microbiology, Institute of Genetics and Microbiology, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland
| | - Agnieszka Jama-Kmiecik
- 1Department of Basic Sciences, Faculty of Health Sciences, Wroclaw Medical University, Chalubinskiego 4, 50-368 Wroclaw, Poland
| | - Magdalena Frej-Madrzak
- 1Department of Basic Sciences, Faculty of Health Sciences, Wroclaw Medical University, Chalubinskiego 4, 50-368 Wroclaw, Poland
| | - Marta Ksiazczyk
- 2Department of Microbiology, Institute of Genetics and Microbiology, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland
| | - Gabriela Bugla-Ploskonska
- 2Department of Microbiology, Institute of Genetics and Microbiology, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland
| | - Irena Choroszy-Krol
- 1Department of Basic Sciences, Faculty of Health Sciences, Wroclaw Medical University, Chalubinskiego 4, 50-368 Wroclaw, Poland
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24
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Menikpurage IP, Barraza D, Meléndez AB, Strebe S, Mera PE. The B12 receptor BtuB alters the membrane integrity of Caulobacter crescentus. MICROBIOLOGY-SGM 2019; 165:311-323. [PMID: 30628887 DOI: 10.1099/mic.0.000753] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vitamin B12 is one of the most complex biomolecules in nature. Since few organisms can synthesize B12de novo, most bacteria utilize highly sensitive and specialized transporters to scavenge B12 and its precursors. In Gram-negative bacteria, BtuB is the outer membrane TonB-dependent receptor for B12. In the fresh water bacterium Caulobacter crescentus, btuB is among the most highly expressed genes. In this study, we characterized the function of BtuB in C. crescentus and unveiled a potential new function of this receptor involved in cellular fitness. Under standard minimal or rich growth conditions, we found that supplements of vitamin B12 to cultures of C. crescentus provided no significant advantage in growth rate. Using a B12 methionine auxotroph, we showed that BtuB in C. crescentus is capable of transporting B12 at low pico-molar range. A btuB knockout strain displayed higher sensitivity to detergents and to changes in osmotic pressure compared to the wild-type. Electron micrographs of this knockout strain revealed a morphology defect. The sensitivity observed in the btuB knockout strain was not due to changes in membrane permeability or altered S-layer levels. Our results demonstrate that btuB deletion mutants exhibit increased susceptibility to membrane stressors, suggesting a potential role of this receptor in membrane homeostasis. Because we only tested BtuB's function under laboratory conditions, we cannot eliminate the possibility that BtuB also plays a key role as a B12 scavenger in C. crescentus when growing in its highly variable and nutrient-limited natural environment.
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Affiliation(s)
- Inoka P Menikpurage
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA
| | - Daniela Barraza
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA
| | - Ady B Meléndez
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA
| | - Sierra Strebe
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA
| | - Paola E Mera
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA
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25
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Zupok A, Iobbi-Nivol C, Méjean V, Leimkühler S. The regulation of Moco biosynthesis and molybdoenzyme gene expression by molybdenum and iron in bacteria. Metallomics 2019; 11:1602-1624. [DOI: 10.1039/c9mt00186g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The regulation of the operons involved in Moco biosynthesis is dependent on the availability of Fe–S clusters in the cell.
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Affiliation(s)
- Arkadiusz Zupok
- University of Potsdam
- Institute of Biochemistry and Biology
- Molecular Enzymology
- Potsdam-Golm
- Germany
| | - Chantal Iobbi-Nivol
- Aix-Marseille Université
- Institut de Microbiologie de la Méditerranée
- Laboratoire de Bioénergétique et Ingénierie des Protéines
- Centre National de la Recherche Scientifique
- Marseille
| | - Vincent Méjean
- Aix-Marseille Université
- Institut de Microbiologie de la Méditerranée
- Laboratoire de Bioénergétique et Ingénierie des Protéines
- Centre National de la Recherche Scientifique
- Marseille
| | - Silke Leimkühler
- University of Potsdam
- Institute of Biochemistry and Biology
- Molecular Enzymology
- Potsdam-Golm
- Germany
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26
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Kalidasan V, Azman A, Joseph N, Kumar S, Awang Hamat R, Neela VK. Putative Iron Acquisition Systems in Stenotrophomonas maltophilia. Molecules 2018; 23:E2048. [PMID: 30115820 PMCID: PMC6222749 DOI: 10.3390/molecules23082048] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/22/2018] [Accepted: 07/23/2018] [Indexed: 12/21/2022] Open
Abstract
Iron has been shown to regulate biofilm formation, oxidative stress response and several pathogenic mechanisms in Stenotrophomonas maltophilia. Thus, the present study is aimed at identifying various iron acquisition systems and iron sources utilized during iron starvation in S. maltophilia. The annotations of the complete genome of strains K279a, R551-3, D457 and JV3 through Rapid Annotations using Subsystems Technology (RAST) revealed two putative subsystems to be involved in iron acquisition: the iron siderophore sensor and receptor system and the heme, hemin uptake and utilization systems/hemin transport system. Screening for these acquisition systems in S. maltophilia showed the presence of all tested functional genes in clinical isolates, but only a few in environmental isolates. NanoString nCounter Elements technology, applied to determine the expression pattern of the genes under iron-depleted condition, showed significant expression for FeSR (6.15-fold), HmuT (12.21-fold), Hup (5.46-fold), ETFb (2.28-fold), TonB (2.03-fold) and Fur (3.30-fold). The isolates, when further screened for the production and chemical nature of siderophores using CAS agar diffusion (CASAD) and Arnows's colorimetric assay, revealed S. maltophilia to produce catechol-type siderophore. Siderophore production was also tested through liquid CAS assay and was found to be greater in the clinical isolate (30.8%) compared to environmental isolates (4%). Both clinical and environmental isolates utilized hemoglobin, hemin, transferrin and lactoferrin as iron sources. All data put together indicates that S. maltophilia utilizes siderophore-mediated and heme-mediated systems for iron acquisition during iron starvation. These data need to be further confirmed through several knockout studies.
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Affiliation(s)
- V Kalidasan
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor Darul Ehsan, Malaysia.
| | - Adleen Azman
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor Darul Ehsan, Malaysia.
| | - Narcisse Joseph
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor Darul Ehsan, Malaysia.
| | - Suresh Kumar
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor Darul Ehsan, Malaysia.
| | - Rukman Awang Hamat
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor Darul Ehsan, Malaysia.
| | - Vasantha Kumari Neela
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor Darul Ehsan, Malaysia.
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27
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Rosario D, Benfeitas R, Bidkhori G, Zhang C, Uhlen M, Shoaie S, Mardinoglu A. Understanding the Representative Gut Microbiota Dysbiosis in Metformin-Treated Type 2 Diabetes Patients Using Genome-Scale Metabolic Modeling. Front Physiol 2018; 9:775. [PMID: 29988585 PMCID: PMC6026676 DOI: 10.3389/fphys.2018.00775] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 06/04/2018] [Indexed: 01/21/2023] Open
Abstract
Dysbiosis in the gut microbiome composition may be promoted by therapeutic drugs such as metformin, the world’s most prescribed antidiabetic drug. Under metformin treatment, disturbances of the intestinal microbes lead to increased abundance of Escherichia spp., Akkermansia muciniphila, Subdoligranulum variabile and decreased abundance of Intestinibacter bartlettii. This alteration may potentially lead to adverse effects on the host metabolism, with the depletion of butyrate producer genus. However, an increased production of butyrate and propionate was verified in metformin-treated Type 2 diabetes (T2D) patients. The mechanisms underlying these nutritional alterations and their relation with gut microbiota dysbiosis remain unclear. Here, we used Genome-scale Metabolic Models of the representative gut bacteria Escherichia spp., I. bartlettii, A. muciniphila, and S. variabile to elucidate their bacterial metabolism and its effect on intestinal nutrient pool, including macronutrients (e.g., amino acids and short chain fatty acids), minerals and chemical elements (e.g., iron and oxygen). We applied flux balance analysis (FBA) coupled with synthetic lethality analysis interactions to identify combinations of reactions and extracellular nutrients whose absence prevents growth. Our analyses suggest that Escherichia sp. is the bacteria least vulnerable to nutrient availability. We have also examined bacterial contribution to extracellular nutrients including short chain fatty acids, amino acids, and gasses. For instance, Escherichia sp. and S. variabile may contribute to the production of important short chain fatty acids (e.g., acetate and butyrate, respectively) involved in the host physiology under aerobic and anaerobic conditions. We have also identified pathway susceptibility to nutrient availability and reaction changes among the four bacteria using both FBA and flux variability analysis. For instance, lipopolysaccharide synthesis, nucleotide sugar metabolism, and amino acid metabolism are pathways susceptible to changes in Escherichia sp. and A. muciniphila. Our observations highlight important commensal and competing behavior, and their association with cellular metabolism for prevalent gut microbes. The results of our analysis have potential important implications for development of new therapeutic approaches in T2D patients through the development of prebiotics, probiotics, or postbiotics.
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Affiliation(s)
- Dorines Rosario
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Rui Benfeitas
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Gholamreza Bidkhori
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Cheng Zhang
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Mathias Uhlen
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Saeed Shoaie
- Centre for Host-Microbiome Interactions, Dental Institute, King's College London, London, United Kingdom.,Centre for Translational Microbiome Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
| | - Adil Mardinoglu
- Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden.,Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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28
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Transcriptome Profiling Reveals Interplay of Multifaceted Stress Response in Escherichia coli on Exposure to Glutathione and Ciprofloxacin. mSystems 2018; 3:mSystems00001-18. [PMID: 29468195 PMCID: PMC5811628 DOI: 10.1128/msystems.00001-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/22/2018] [Indexed: 12/16/2022] Open
Abstract
The emergence and spread of multidrug-resistant bacterial strains have serious medical and clinical consequences. In addition, the rate of discovery of new therapeutic antibiotics has been inadequate in last few decades. Fluoroquinolone antibiotics such as ciprofloxacin represent a precious therapeutic resource in the fight against bacterial pathogens. However, these antibiotics have been gradually losing their appeal due to the emergence and buildup of resistance to them. In this report, we shed light on the genome-level expression changes in bacteria with respect to glutathione (GSH) exposure which act as a trigger for fluoroquinolone antibiotic resistance. The knowledge about different bacterial stress response pathways under conditions of exposure to the conditions described above and potential points of cross talk between them could help us in understanding and formulating the conditions under which buildup and spread of antibiotic resistance could be minimized. Our findings are also relevant because GSH-induced genome-level expression changes have not been reported previously for E. coli. We have previously reported that supplementation of exogenous glutathione (GSH) promotes ciprofloxacin resistance in Escherichia coli by neutralizing antibiotic-induced oxidative stress and by enhancing the efflux of antibiotic. In the present study, we used a whole-genome microarray as a tool to analyze the system-level transcriptomic changes of E. coli on exposure to GSH and/or ciprofloxacin. The microarray data revealed that GSH supplementation affects redox function, transport, acid shock, and virulence genes of E. coli. The data further highlighted the interplay of multiple underlying stress response pathways (including those associated with the genes mentioned above and DNA damage repair genes) at the core of GSH, offsetting the effect of ciprofloxacin in E. coli. The results of a large-scale validation of the transcriptomic data using reverse transcription-quantitative PCR (RT-qPCR) analysis for 40 different genes were mostly in agreement with the microarray results. The altered growth profiles of 12 different E. coli strains carrying deletions in the specific genes mentioned above with GSH and/or ciprofloxacin supplementation implicate these genes in the GSH-mediated phenotype not only at the molecular level but also at the functional level. We further associated GSH supplementation with increased acid shock survival of E. coli on the basis of our transcriptomic data. Taking the data together, it can be concluded that GSH supplementation influences the expression of genes of multiple stress response pathways apart from its effect(s) at the physiological level to counter the action of ciprofloxacin in E. coli. IMPORTANCE The emergence and spread of multidrug-resistant bacterial strains have serious medical and clinical consequences. In addition, the rate of discovery of new therapeutic antibiotics has been inadequate in last few decades. Fluoroquinolone antibiotics such as ciprofloxacin represent a precious therapeutic resource in the fight against bacterial pathogens. However, these antibiotics have been gradually losing their appeal due to the emergence and buildup of resistance to them. In this report, we shed light on the genome-level expression changes in bacteria with respect to glutathione (GSH) exposure which act as a trigger for fluoroquinolone antibiotic resistance. The knowledge about different bacterial stress response pathways under conditions of exposure to the conditions described above and potential points of cross talk between them could help us in understanding and formulating the conditions under which buildup and spread of antibiotic resistance could be minimized. Our findings are also relevant because GSH-induced genome-level expression changes have not been reported previously for E. coli.
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29
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Klahn P, Brönstrup M. Bifunctional antimicrobial conjugates and hybrid antimicrobials. Nat Prod Rep 2017; 34:832-885. [PMID: 28530279 DOI: 10.1039/c7np00006e] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: up to the end of 2016Novel antimicrobial drugs are continuously needed to counteract bacterial resistance development. An innovative molecular design strategy for novel antibiotic drugs is based on the hybridization of an antibiotic with a second functional entity. Such conjugates can be grouped into two major categories. In the first category (antimicrobial hybrids), both functional elements of the hybrid exert antimicrobial activity. Due to the dual targeting, resistance development can be significantly impaired, the pharmacokinetic properties can be superior compared to combination therapies with the single antibiotics, and the antibacterial potency is often enhanced in a synergistic manner. In the second category (antimicrobial conjugates), one functional moiety controls the accumulation of the other part of the conjugate, e.g. by mediating an active transport into the bacterial cell or blocking the efflux. This approach is mostly applied to translocate compounds across the cell envelope of Gram-negative bacteria through membrane-embedded transporters (e.g. siderophore transporters) that provide nutrition and signalling compounds to the cell. Such 'Trojan Horse' approaches can expand the antibacterial activity of compounds against Gram-negative pathogens, or offer new options for natural products that could not be developed as standalone antibiotics, e.g. due to their toxicity.
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Affiliation(s)
- P Klahn
- Department for Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany. and Institute for Organic Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
| | - M Brönstrup
- Department for Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany.
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30
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Tanabe T. Regulation of the Expression of Iron-acquisition System Genes in Pathogenic Vibrio Species. YAKUGAKU ZASSHI 2016; 136:1525-1532. [PMID: 27803484 DOI: 10.1248/yakushi.16-00192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The genus Vibrio includes >70 species, of which roughly a dozen cause vibriosis such as gastroenteritis, wound infections, and septicemia. Most bacteria, including Vibrio species, require iron for survival and growth. However, the bioavailability of iron is extremely low because it is usually present as an insoluble ferric complex in an aerobic environment or is bound to iron-binding proteins in mammalian hosts. Therefore many bacteria have developed iron acquisition systems, including biosynthesis and secretion of low-molecular-mass iron-chelating compounds called siderophores, and uptake of iron-bound siderophores into bacterial cells through specific active transport systems. Vibrio parahaemolyticus, a major pathogenic Vibrio species, contains multiple iron-acquisition systems mediated by its own siderophore vibrioferrin and several xenosiderophores produced by other microorganisms. In this review, I have focused on the transcriptional and posttranscriptional regulation of genes encoding iron acquisition systems in V. parahaemolyticus. All genes involved in its iron acquisition systems are repressed by Fur, which acts as a ferrous-dependent transcriptional repressor. Furthermore, the stability of polycistronic mRNA involved in vibrioferrin biosynthesis is positively regulated by a small RNA, RyhB, which is repressed by Fur. Expression of PeuA receptor required for utilization of a xenosiderophore, enterobactin, occurs under iron-limiting conditions at alkaline pH. PeuA expression is induced by a two-component regulatory system, PeuRS, which enhances expression of an alternative peuA transcript without an intrinsic translation-inhibitory structure in response to changes in alkaline pH.
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Affiliation(s)
- Tomotaka Tanabe
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University
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Abdelhamed H, Lu J, Lawrence ML, Karsi A. Ferric hydroxamate uptake system contributes to Edwardsiella ictaluri virulence. Microb Pathog 2016; 100:195-200. [PMID: 27666508 DOI: 10.1016/j.micpath.2016.09.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/13/2016] [Accepted: 09/21/2016] [Indexed: 11/16/2022]
Abstract
Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen causing enteric septicemia in fish, particularly in channel catfish. Ferric iron is an essential micronutrient for bacterial survival, and some bacterial pathogens use secreted hydroxamate-type siderophores to chelate iron in host tissues. Siderophore-iron complexes are taken up by these bacteria via the ferric hydroxamate uptake (Fhu) system. In E. ictaluri, the Fhu system consists of fhuC, fhuD, fhuB, and fhuA genes. However, the importance of the Fhu system in E. ictaluri virulence has not been investigated completely. Here, we present construction of E. ictaluri fhuD and fhuB mutants (EiΔfhuD and EiΔfhuB) by in-frame gene deletion and evaluation of the mutants' virulence and immunogenicity in channel catfish fingerlings and fry. Immersion challenges showed that EiΔfhuD was not significantly attenuated (p < 0.05) in catfish fingerlings, whereas EiΔfhuB was significantly attenuated (p < 0.01). Catfish fingerlings immunized with EiΔfhuD and EiΔfhuB showed 100% and 97.62% survival, respectively. Fry immersion challenges indicated EiΔfhuB was also significantly attenuated (p < 0.05) in two-week old fry compared to the wild-type (48.96% vs. 82.14% mortalities). The survival rate in the fry vaccinated with EiΔfhuB was significantly higher (p < 0.05) than that of non-vaccinated fry (96.77% vs. 21.42% survival). Our data indicates that the fhuB gene, but not the fhuD gene, contributes to E. ictaluri virulence.
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Affiliation(s)
- Hossam Abdelhamed
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA
| | - Jingjun Lu
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA
| | - Mark L Lawrence
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA
| | - Attila Karsi
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.
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Tobias NJ, Heinrich AK, Eresmann H, Wright PR, Neubacher N, Backofen R, Bode HB. Photorhabdus‐nematode symbiosis is dependent onhfq‐mediated regulation of secondary metabolites. Environ Microbiol 2016; 19:119-129. [DOI: 10.1111/1462-2920.13502] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/16/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Nicholas J. Tobias
- Fachbereich BiowissenschaftenMerck Stiftungsprofessur für Molekulare Biotechnologie, Goethe Universität FrankfurtFrankfurt am Main Germany
| | - Antje K. Heinrich
- Fachbereich BiowissenschaftenMerck Stiftungsprofessur für Molekulare Biotechnologie, Goethe Universität FrankfurtFrankfurt am Main Germany
| | - Helena Eresmann
- Fachbereich BiowissenschaftenMerck Stiftungsprofessur für Molekulare Biotechnologie, Goethe Universität FrankfurtFrankfurt am Main Germany
| | - Patrick R. Wright
- Department of Computer ScienceBioinformatics Group, Albert Ludwigs University FreiburgFreiburg Germany
| | - Nick Neubacher
- Fachbereich BiowissenschaftenMerck Stiftungsprofessur für Molekulare Biotechnologie, Goethe Universität FrankfurtFrankfurt am Main Germany
| | - Rolf Backofen
- Department of Computer ScienceBioinformatics Group, Albert Ludwigs University FreiburgFreiburg Germany
- BIOSS Centre for Biological Signaling Studies, University of FreiburgFreiburg Germany
| | - Helge B. Bode
- Fachbereich BiowissenschaftenMerck Stiftungsprofessur für Molekulare Biotechnologie, Goethe Universität FrankfurtFrankfurt am Main Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe Universität FrankfurtFrankfurt am Main Germany
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Sekine Y, Tanzawa T, Tanaka Y, Ishimori K, Uchida T. Cytoplasmic Heme-Binding Protein (HutX) from Vibrio cholerae Is an Intracellular Heme Transport Protein for the Heme-Degrading Enzyme, HutZ. Biochemistry 2016; 55:884-93. [DOI: 10.1021/acs.biochem.5b01273] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yukari Sekine
- Graduate
School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
| | - Takehito Tanzawa
- Graduate
School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yoshikazu Tanaka
- Faculty
of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
- PRESTO, Japan Science and Technology Agency, Sapporo 060-0810, Japan
| | - Koichiro Ishimori
- Graduate
School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
- Department
of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takeshi Uchida
- Graduate
School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
- Department
of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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Dong Q, Bauer CE. Transcriptome analysis of cyst formation in Rhodospirillum centenum reveals large global changes in expression during cyst development. BMC Genomics 2015; 16:68. [PMID: 25758168 PMCID: PMC4340629 DOI: 10.1186/s12864-015-1250-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 01/15/2015] [Indexed: 01/11/2023] Open
Abstract
Background Rhodospirillum centenum is a photosynthetic member of the Gram-negative Azospirillum clade members of which exhibit a complex developmental life-cycle featuring morphologically distinct cell types. Under periods of nutrient deprivation, replicative vegetative cells differentiate into metabolically dormant cysts that survive harsh environmental stresses such as desiccation. Encystment involves a multi-stage developmental process that includes the rounding of cells, production of large intracellular storage granules of poly-hydroxybutyrate (PHB) and the excretion of a protective exopolysaccharide coating that envelops dormant cysts. Results To study the process of cyst development, we performed RNA-seq studies on cells that were induced to undergo cyst development. To assay for temporal changes in gene expression, RNA was extracted at 4, 24, 48, 72, 96 hours during development and subjected to deep sequence analysis. These results show that 812 genes exhibit log2 ≥ 1.5-fold changes in expression over a 96 hour cyst induction period demonstrating large global changes in gene expression during cyst development. Conclusions Notable changes in expression occurred in numerous genes involved in cell wall and lipid biosynthesis, metabolic enzymes, and numerous regulatory genes such as histidine kinases and transcription factors. Many genes involved in protein synthesis and DNA replication were also significantly reduced during late stages of cyst development. Genes previously identified by genetic screens as being critical for cyst development also exhibited changes of expression during cyst induction. This study provides the first transcriptome profile of global changes in gene expression that occur during development of cysts in a Gram-negative species. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1250-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qian Dong
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN, 47405, USA.
| | - Carl E Bauer
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN, 47405, USA.
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Abstract
Here we present an extensive genomic and genetic analysis of Escherichia coli strains of serotype O78 that represent the major cause of avian colisepticemia, an invasive infection caused by avian pathogenic Escherichia coli (APEC) strains. It is associated with high mortality and morbidity, resulting in significant economic consequences for the poultry industry. To understand the genetic basis of the virulence of avian septicemic E. coli, we sequenced the entire genome of a clinical isolate of serotype O78—O78:H19 ST88 isolate 789 (O78-9)—and compared it with three publicly available APEC O78 sequences and one complete genome of APEC serotype O1 strain. Although there was a large variability in genome content between the APEC strains, several genes were conserved, which are potentially critical for colisepticemia. Some of these genes are present in multiple copies per genome or code for gene products with overlapping function, signifying their importance. A systematic deletion of each of these virulence-related genes identified three systems that are conserved in all septicemic strains examined and are critical for serum survival, a prerequisite for septicemia. These are the plasmid-encoded protein, the defective ETT2 (E. coli type 3 secretion system 2) type 3 secretion system ETT2sepsis, and iron uptake systems. Strain O78-9 is the only APEC O78 strain that also carried the regulon coding for yersiniabactin, the iron binding system of the Yersinia high-pathogenicity island. Interestingly, this system is the only one that cannot be complemented by other iron uptake systems under iron limitation and in serum. Avian colisepticemia is a severe systemic disease of birds causing high morbidity and mortality and resulting in severe economic losses. The bacteria associated with avian colisepticemia are highly antibiotic resistant, making antibiotic treatment ineffective, and there is no effective vaccine due to the multitude of serotypes involved. To understand the disease and work out strategies to combat it, we performed an extensive genomic and genetic analysis of Escherichia coli strains of serotype O78, the major cause of the disease. We identified several potential virulence factors, conserved in all the colisepticemic strains examined, and determined their contribution to growth in serum, an absolute requirement for septicemia. These findings raise the possibility that specific vaccines or drugs can be developed against these critical virulence factors to help combat this economically important disease.
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Yamamoto K. The hierarchic network of metal-response transcription factors in Escherichia coli. Biosci Biotechnol Biochem 2014; 78:737-47. [PMID: 25035972 DOI: 10.1080/09168451.2014.915731] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Enterobacteria such as Escherichia coli are able to survive under various environments within host animals by changes of the expression pattern of its genome. The selective expression of genes in its genome takes place by controlling the promoter recognition properties of RNA polymerase by protein-protein interplays with transcription factors. In this review, I describe the regulatory network formed by the metal-sensing transcription factors in E. coli. Comprehensive analyses identify the set of regulation targets for a total of 13 metal-response transcription factors, indicating that nine species of transcription factors are local regulators while four species of transcription factors are global regulators. The signal transduction pathways for these metal-response regulons show not only the complex cross-talks but also the hierarchic multi-regulatory network. This regulatory network seems to play a role for E. coli survival to colonize in a large intestine within host animals.
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Affiliation(s)
- Kaneyoshi Yamamoto
- a Department of Frontier Bioscience and Micro-Nano Technology Research Center , Hosei University , Koganei, Tokyo , Japan
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Physiological and proteomic analysis of Escherichia coli iron-limited chemostat growth. J Bacteriol 2014; 196:2748-61. [PMID: 24837288 DOI: 10.1128/jb.01606-14] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Iron bioavailability is a major limiter of bacterial growth in mammalian host tissue and thus represents an important area of study. Escherichia coli K-12 metabolism was studied at four levels of iron limitation in chemostats using physiological and proteomic analyses. The data documented an E. coli acclimation gradient where progressively more severe iron scarcity resulted in a larger percentage of substrate carbon being directed into an overflow metabolism accompanied by a decrease in biomass yield on glucose. Acetate was the primary secreted organic by-product for moderate levels of iron limitation, but as stress increased, the metabolism shifted to secrete primarily lactate (∼70% of catabolized glucose carbon). Proteomic analysis reinforced the physiological data and quantified relative increases in glycolysis enzyme abundance and decreases in tricarboxylic acid (TCA) cycle enzyme abundance with increasing iron limitation stress. The combined data indicated that E. coli responds to limiting iron by investing the scarce resource in essential enzymes, at the cost of catabolic efficiency (i.e., downregulating high-ATP-yielding pathways containing enzymes with large iron requirements, like the TCA cycle). Acclimation to iron-limited growth was contrasted experimentally with acclimation to glucose-limited growth to identify both general and nutrient-specific acclimation strategies. While the iron-limited cultures maximized biomass yields on iron and increased expression of iron acquisition strategies, the glucose-limited cultures maximized biomass yields on glucose and increased expression of carbon acquisition strategies. This study quantified ecologically competitive acclimations to nutrient limitations, yielding knowledge essential for understanding medically relevant bacterial responses to host and to developing intervention strategies.
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Global identification of genes affecting iron-sulfur cluster biogenesis and iron homeostasis. J Bacteriol 2014; 196:1238-49. [PMID: 24415728 DOI: 10.1128/jb.01160-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Iron-sulfur (Fe-S) clusters are ubiquitous cofactors that are crucial for many physiological processes in all organisms. In Escherichia coli, assembly of Fe-S clusters depends on the activity of the iron-sulfur cluster (ISC) assembly and sulfur mobilization (SUF) apparatus. However, the underlying molecular mechanisms and the mechanisms that control Fe-S cluster biogenesis and iron homeostasis are still poorly defined. In this study, we performed a global screen to identify the factors affecting Fe-S cluster biogenesis and iron homeostasis using the Keio collection, which is a library of 3,815 single-gene E. coli knockout mutants. The approach was based on radiolabeling of the cells with [2-(14)C]dihydrouracil, which entirely depends on the activity of an Fe-S enzyme, dihydropyrimidine dehydrogenase. We identified 49 genes affecting Fe-S cluster biogenesis and/or iron homeostasis, including 23 genes important only under microaerobic/anaerobic conditions. This study defines key proteins associated with Fe-S cluster biogenesis and iron homeostasis, which will aid further understanding of the cellular mechanisms that coordinate the processes. In addition, we applied the [2-(14)C]dihydrouracil-labeling method to analyze the role of amino acid residues of an Fe-S cluster assembly scaffold (IscU) as a model of the Fe-S cluster assembly apparatus. The analysis showed that Cys37, Cys63, His105, and Cys106 are essential for the function of IscU in vivo, demonstrating the potential of the method to investigate in vivo function of proteins involved in Fe-S cluster assembly.
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Cheng W, Li Q, Jiang YL, Zhou CZ, Chen Y. Structures of Streptococcus pneumoniae PiaA and its complex with ferrichrome reveal insights into the substrate binding and release of high affinity iron transporters. PLoS One 2013; 8:e71451. [PMID: 23951167 PMCID: PMC3741162 DOI: 10.1371/journal.pone.0071451] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 07/01/2013] [Indexed: 11/24/2022] Open
Abstract
Iron scarcity is one of the nutrition limitations that the Gram-positive infectious pathogens Streptococcus pneumoniae encounter in the human host. To guarantee sufficient iron supply, the ATP binding cassette (ABC) transporter Pia is employed to uptake iron chelated by hydroxamate siderophore, via the membrane-anchored substrate-binding protein PiaA. The high affinity towards ferrichrome enables PiaA to capture iron at a very low concentration in the host. We presented here the crystal structures of PiaA in both apo and ferrichrome-complexed forms at 2.7 and 2.1 Å resolution, respectively. Similar to other class III substrate binding proteins, PiaA is composed of an N-terminal and a C-terminal domain bridged by an α-helix. At the inter-domain cleft, a molecule of ferrichrome is stabilized by a number of highly conserved residues. Upon ferrichrome binding, two highly flexible segments at the entrance of the cleft undergo significant conformational changes, indicating their contribution to the binding and/or release of ferrichrome. Superposition to the structure of Escherichia coli ABC transporter BtuF enabled us to define two conserved residues: Glu119 and Glu262, which were proposed to form salt bridges with two arginines of the permease subunits. Further structure-based sequence alignment revealed that the ferrichrome binding pattern is highly conserved in a series of PiaA homologs encoded by both Gram-positive and negative bacteria, which were predicted to be sensitive to albomycin, a sideromycin antibiotic derived from ferrichrome.
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Affiliation(s)
- Wang Cheng
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Qiong Li
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yong-Liang Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Cong-Zhao Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yuxing Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
- * E-mail:
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Tomita N, Mohammad MM, Niedzwiecki DJ, Ohta M, Movileanu L. Does the lipid environment impact the open-state conductance of an engineered β-barrel protein nanopore? BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1828:1057-65. [PMID: 23246446 PMCID: PMC3560310 DOI: 10.1016/j.bbamem.2012.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 11/16/2012] [Accepted: 12/04/2012] [Indexed: 12/11/2022]
Abstract
Using rational membrane protein design, we were recently able to obtain a β-barrel protein nanopore that was robust under an unusually broad range of experimental circumstances. This protein nanopore was based upon the native scaffold of the bacterial ferric hydroxamate uptake component A (FhuA) of Escherichia coli. In this work, we expanded the examinations of the open-state current of this engineered protein nanopore, also called FhuA ΔC/Δ4L, employing an array of lipid bilayer systems that contained charged and uncharged as well as conical and cylindrical lipids. Remarkably, systematical single-channel analysis of FhuA ΔC/Δ4L indicated that most of its biophysical features, such as the unitary conductance and the stability of the open-state current, were not altered under the conditions tested in this work. However, electrical recordings at high transmembrane potentials revealed that the presence of conical phospholipids within the bilayer catalyzes the first, stepwise current transition of the FhuA ΔC/Δ4L protein nanopore to a lower-conductance open state. This study reinforces the stability of the open-state current of the engineered FhuA ΔC/Δ4L protein nanopore under various experimental conditions, paving the way for further critical developments in biosensing and molecular biomedical diagnosis.
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Affiliation(s)
- Noriko Tomita
- Department of Physics, Syracuse University, Syracuse, New York 13244-1130, USA
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | | | | | - Makoto Ohta
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Liviu Movileanu
- Department of Physics, Syracuse University, Syracuse, New York 13244-1130, USA
- Structural Biology, Biochemistry, and Biophysics Program, Syracuse University, Syracuse, New York 13244-4100, USA
- Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York 13244, USA
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Torda AE, Groves MR, Wedderhoff I, Ortiz de Orué Lucana D. Elucidation of haem-binding sites in the actinobacterial protein HbpS. FEMS Microbiol Lett 2013; 342:106-12. [PMID: 23373615 DOI: 10.1111/1574-6968.12093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 01/28/2013] [Accepted: 01/28/2013] [Indexed: 11/28/2022] Open
Abstract
The extracellular haem-binding protein from Streptomyces reticuli (HbpS) has been shown to be involved in redox sensing and to bind haem. However, the residues involved in haem coordination are unknown. Structural alignments to distantly related haem-binding proteins from Mycobacterium tuberculosis were used to identify a candidate haem-coordinating residue, and site-directed mutagenesis with UV/Vis spectroscopy was used to assess haem binding in vivo and in vitro. We present strong evidence that HbpS belongs to the small set of proteins, which do not use histidine to coordinate the metal in the haem group. Further spectroscopic evidence strongly indicates that threonine 113 is actively involved in coordination of haem. Subsequent protein/haem titration experiments show a 1 : 2, protein/haem stoichiometry. We also present data showing the degradation of haem by HbpS in vivo. Because HbpS is conserved in many Actinobacteria, the presented results are applicable to related species.
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Affiliation(s)
- Andrew E Torda
- Centre for Bioinformatics, Hamburg University, Hamburg, Germany
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Piggot TJ, Holdbrook DA, Khalid S. Conformational dynamics and membrane interactions of the E. coli outer membrane protein FecA: A molecular dynamics simulation study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:284-93. [DOI: 10.1016/j.bbamem.2012.08.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 08/02/2012] [Accepted: 08/23/2012] [Indexed: 11/25/2022]
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Chen Q, Li J, Wu Y, Shen F, Yao M. Biological responses of Gram-positive and Gram-negative bacteria to nZVI (Fe0), Fe2+ and Fe3+. RSC Adv 2013. [DOI: 10.1039/c3ra40570b] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Iron-sulphur clusters, their biosynthesis, and biological functions in protozoan parasites. ADVANCES IN PARASITOLOGY 2013; 83:1-92. [PMID: 23876871 DOI: 10.1016/b978-0-12-407705-8.00001-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Fe-S clusters are ensembles of sulphide-linked di-, tri-, and tetra-iron centres of a variety of metalloproteins that play important roles in reduction and oxidation of mitochondrial electron transport, energy metabolism, regulation of gene expression, cell survival, nitrogen fixation, and numerous other metabolic pathways. The Fe-S clusters are assembled by one of four distinct systems: NIF, SUF, ISC, and CIA machineries. The ISC machinery is a house-keeping system conserved widely from prokaryotes to higher eukaryotes, while the other systems are present in a limited range of organisms and play supplementary roles under certain conditions such as stress. Fe-S cluster-containing proteins and the components required for Fe-S cluster biosynthesis are modulated under stress conditions, drug resistance, and developmental stages. It is also known that a defect in Fe-S proteins and Fe-S cluster biogenesis leads to many genetic disorders in humans, which indicates the importance of the systems. In this review, we describe the biological and physiological significance of Fe-S cluster-containing proteins and their biosynthesis in parasitic protozoa including Plasmodium, Trypanosoma, Leishmania, Giardia, Trichomonas, Entamoeba, Cryptosporidium, Blastocystis, and microsporidia. We also discuss the roles of Fe-S cluster biosynthesis in proliferation, differentiation, and stress response in protozoan parasites. The heterogeneity of the systems and the compartmentalization of Fe-S cluster biogenesis in the protozoan parasites likely reflect divergent evolution under highly diverse environmental niches, and influence their parasitic lifestyle and pathogenesis. Finally, both Fe-S cluster-containing proteins and their biosynthetic machinery in protozoan parasites are remarkably different from those in their mammalian hosts. Thus, they represent a rational target for the development of novel chemotherapeutic and prophylactic agents against protozoan infections.
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Saha R, Saha N, Donofrio RS, Bestervelt LL. Microbial siderophores: a mini review. J Basic Microbiol 2012; 53:303-17. [PMID: 22733623 DOI: 10.1002/jobm.201100552] [Citation(s) in RCA: 215] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 01/20/2012] [Indexed: 01/22/2023]
Abstract
Iron is one of the major limiting factors and essential nutrients of microbial life. Since in nature it is not readily available in the preferred form, microorganisms produce small high affinity chelating molecules called siderophores for its acquisition. Microorganisms produce a wide variety of siderophores controlled at the molecular level by different genes to accumulate, mobilize and transport iron for metabolism. Siderophores also play a critical role in the expression of virulence and development of biofilms by different microbes. Apart from maintaining microbial life, siderophores can be harnessed for the sustainability of human, animals and plants. With the advent of modern molecular tools, a major breakthrough is taking place in the understanding of the multifaceted role of siderophores in nature. This mini review is intended to provide a general overview on siderophore along with its role and applications.
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Affiliation(s)
- Ratul Saha
- Department of Microbiology and Molecular Biology, NSF International, Ann Arbor, MI, USA.
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Holden KM, Browning GF, Noormohammadi AH, Markham PF, Marenda MS. TonB is essential for virulence in avian pathogenic Escherichia coli. Comp Immunol Microbiol Infect Dis 2012; 35:129-38. [DOI: 10.1016/j.cimid.2011.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 12/05/2011] [Accepted: 12/06/2011] [Indexed: 11/25/2022]
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49
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Schalk IJ, Mislin GLA, Brillet K. Structure, function and binding selectivity and stereoselectivity of siderophore-iron outer membrane transporters. CURRENT TOPICS IN MEMBRANES 2012; 69:37-66. [PMID: 23046646 DOI: 10.1016/b978-0-12-394390-3.00002-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
To get access to iron, microorganisms produce and release into their environment small organic metal chelators called siderophores. In parallel, they produce siderophore-iron outer membrane transporters (also called TonB-Dependent Transporters or TBDT) embedded in the outer membrane; these proteins actively reabsorb the siderophore loaded with iron from the extracellular medium. This active uptake requires energy in the form of the proton motive force transferred from the inner membrane to the outer membrane transporter via the inner membrane TonB complex. Siderophores produced by microorganisms are structurally very diverse with molecular weights of 150 up to 2000Da. Siderophore-iron uptake from the extracellular medium by TBDTs is a highly selective and sometimes even stereoselective process, with each siderophore having a specific TBDT. Unlike the siderophores, all TBDTs have similar structures and belong to the outer membrane β-barrel protein superfamily. The way in which the siderophore-iron complex passes through the TBDT is still unclear. In some bacteria, TBDTs are also partners of signaling cascades regulating the expression of proteins involved in siderophore biosynthesis and siderophore-iron acquisition.
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Affiliation(s)
- Isabelle J Schalk
- UMR 7242, Université de Strasbourg-CNRS, ESBS, Boulevard Sébastien Brant, Strasbourg, France.
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Hensley MP, Gunasekera TS, Easton JA, Sigdel TK, Sugarbaker SA, Klingbeil L, Breece RM, Tierney DL, Crowder MW. Characterization of Zn(II)-responsive ribosomal proteins YkgM and L31 in E. coli. J Inorg Biochem 2011; 111:164-72. [PMID: 22196016 DOI: 10.1016/j.jinorgbio.2011.11.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/27/2011] [Accepted: 11/23/2011] [Indexed: 11/26/2022]
Abstract
RT-PCR and DNA microarrays were used to probe for Zn(II)-responsive genes in E. coli cells that were made Zn(II) deficient. Microarray data revealed 114 genes were significantly up-regulated and 146 genes were significantly down-regulated in Zn(II) deficient conditions. The three most up-regulated genes were (1) znuA, which encodes for a periplasmic protein known to be involved with Zn(II) import, (2) yodA, which encodes for a periplasmic protein with unknown function, and (3) ykgM, which encodes for a ribosomal protein that is thought to be a paralog of ribosomal protein L31. YodA was over-expressed and purified as a maltose binding protein (MBP) fusion protein and shown to tightly bind 4 equivalents of Zn(II). Metal analyses showed that MBP-YkgM does not bind Zn(II). On the other hand, MBP-L31 tightly binds 1 equivalent of Zn(II). EXAFS studies on MBP-L31 suggest a ligand field of 1 histidine, 1 cysteine, and 2 additional N/O scatterers. Site-directed mutagenesis studies suggest that Cys16 coordinates Zn(II) in MBP-L31 and that the other three cysteines do not bind metal. These results are discussed in light of Zn(II) starvation model that has been postulated for B. subtilis.
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Affiliation(s)
- M Patrick Hensley
- Department of Chemistry and Biochemistry, 160 Hughes Hall, Miami University, Oxford, OH 45056, United States
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