1
|
Noell SE, Hellweger FL, Temperton B, Giovannoni SJ. A Reduction of Transcriptional Regulation in Aquatic Oligotrophic Microorganisms Enhances Fitness in Nutrient-Poor Environments. Microbiol Mol Biol Rev 2023; 87:e0012422. [PMID: 36995249 PMCID: PMC10304753 DOI: 10.1128/mmbr.00124-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
In this review, we consider the regulatory strategies of aquatic oligotrophs, microbial cells that are adapted to thrive under low-nutrient concentrations in oceans, lakes, and other aquatic ecosystems. Many reports have concluded that oligotrophs use less transcriptional regulation than copiotrophic cells, which are adapted to high nutrient concentrations and are far more common subjects for laboratory investigations of regulation. It is theorized that oligotrophs have retained alternate mechanisms of regulation, such as riboswitches, that provide shorter response times and smaller amplitude responses and require fewer cellular resources. We examine the accumulated evidence for distinctive regulatory strategies in oligotrophs. We explore differences in the selective pressures copiotrophs and oligotrophs encounter and ask why, although evolutionary history gives copiotrophs and oligotrophs access to the same regulatory mechanisms, they might exhibit distinctly different patterns in how these mechanisms are used. We discuss the implications of these findings for understanding broad patterns in the evolution of microbial regulatory networks and their relationships to environmental niche and life history strategy. We ask whether these observations, which have emerged from a decade of increased investigation of the cell biology of oligotrophs, might be relevant to recent discoveries of many microbial cell lineages in nature that share with oligotrophs the property of reduced genome size.
Collapse
Affiliation(s)
- Stephen E. Noell
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | | | - Ben Temperton
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | | |
Collapse
|
2
|
Cui F, Fan R, Wang D, Li J, Li T. Research progress on iron uptake pathways and mechanisms of foodborne microorganisms and their application in the food sector. Crit Rev Food Sci Nutr 2023:1-19. [PMID: 37099732 DOI: 10.1080/10408398.2023.2204491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Iron is one of the essential nutrients for almost all microorganisms. Under iron-limited conditions, bacteria can secrete siderophores to the outside world to absorb iron for survival. This process requires the coordinated action of energy-transducing proteins, transporters, and receptors. The spoilage factors of some spoilage bacteria and the pathogenic mechanism of pathogenic bacteria are also closely related to siderophores. Meanwhile, some siderophores have also gradually evolved toward beneficial aspects. First, a variety of siderophores are classified into three aspects. In addition, representative iron uptake systems of Gram-negative and Gram-positive bacteria are described in detail to understand the common and specific pathways of iron uptake by various bacteria. In particular, the causes of siderophore-induced bacterial pathogenicity and the methods and mechanisms of inhibiting bacterial iron absorption under the involvement of siderophores are presented. Then, the application of siderophores in the food sector is mainly discussed, such as improving the food quality of dairy products and meat, inhibiting the attack of pathogenic bacteria on food, improving the plant growth environment, and promoting plant growth. Finally, this review highlights the unresolved fate of siderophores in the iron uptake system and emphasizes further development of siderophore-based substitutes for traditional drugs, new antibiotic-resistance drugs, and vaccines in the food and health sectors.
Collapse
Affiliation(s)
- Fangchao Cui
- College of Food Science and Technology, Bohai University, National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Rongsen Fan
- College of Food Science and Technology, Bohai University, National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Dangfeng Wang
- College of Food Science and Technology, Bohai University, National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
- College of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Jianrong Li
- College of Food Science and Technology, Bohai University, National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Tingting Li
- Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, Dalian, China
| |
Collapse
|
3
|
Zhang F, Zhang K, Zhang Z, Chen HQ, Chen XW, Xian XY, Wu YR. Efficient isopropanol-butanol-ethanol (IBE) fermentation by a gene-modified solventogenic Clostridium species under the co-utilization of Fe(III) and butyrate. BIORESOURCE TECHNOLOGY 2023; 373:128751. [PMID: 36805829 DOI: 10.1016/j.biortech.2023.128751] [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: 12/27/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
To elevate the efficiency of acetone-butanol-ethanol (ABE) fermentation by the wild-type strain WK, an optimal co-utilization system (20 mM Fe3+ and 5 g/L butyrate) was established to bring about a 22.22% increment in the yield of ABE mixtures with a significantly enhanced productivity (0.32 g/L/h). With the heterologous introduction of the secondary alcohol dehydrogenase encoded gene (adh), more than 95% of acetone was eliminated to convert 4.5 g/L isopropanol with corresponding increased butanol and ethanol production by 21.08% and 65.45% in the modified strain WK::adh. Under the optimal condition, strain WK::adh was capable of producing a total of 25.46 g/L IBE biosolvents with an enhanced productivity of 0.35 g/L/h by 45.83% over the original conditions. This work for the first time successfully established a synergetic system of co-utilizing Fe(III) and butyrate to demonstrate a feasible and efficient manner for generating the value-added biofuels through the metabolically engineered solventogenic clostridial strain.
Collapse
Affiliation(s)
- Feifei Zhang
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Kan Zhang
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Zhiqian Zhang
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Hai-Qi Chen
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Xiao-Wei Chen
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Xing-You Xian
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Yi-Rui Wu
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China.
| |
Collapse
|
4
|
Lu Q, Zhu X, Long Q, Yi X, Yang A, Long X, Cao D. Comparative Genomics Reveal the Utilization Ability of Variable Carbohydrates as Key Genetic Features of Listeria Pathogens in Their Pathogenic Lifestyles. Pathogens 2022; 11:pathogens11121430. [PMID: 36558765 PMCID: PMC9784484 DOI: 10.3390/pathogens11121430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/20/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND L. monocytogenes and L. ivanovii, the only two pathogens of Listeria, can survive in various environments, having different pathogenic characteristics. However, the genetic basis of their excellent adaptability and differences in pathogenicity has still not been completely elucidated. METHODS We performed a comparative genomic analysis based on 275 L. monocytogenes, 10 L. ivanovii, and 22 non-pathogenic Listeria strains. RESULTS Core/pan-genome analysis revealed that 975 gene families were conserved in all the studied strains. Additionally, 204, 242, and 756 gene families existed uniquely in L. monocytogenes, L. ivanovii, and both, respectively. Functional annotation partially verified that these unique gene families were closely related to their adaptability and pathogenicity. Moreover, the protein-protein interaction (PPI) network analysis of these unique gene sets showed that plenty of carbohydrate transport systems and energy metabolism enzymes were clustered in the networks. Interestingly, ethanolamine-metabolic-process-related proteins were significantly enriched in the PPI network of the unique genes of the Listeria pathogens, which can be understood as a determining factor of their pathogenicity. CONCLUSIONS The utilization capacity of multiple carbon sources of Listeria pathogens, especially ethanolamine, is the key genetic basis for their ability to adapt to various environments and pathogenic lifestyles.
Collapse
Affiliation(s)
- Qunfeng Lu
- Modern Industrial College of Biomedicine and Great Health, Youjiang Medical University for Nationalities, Baise 533000, China
- School of Medical Laboratory Sciences, Youjiang Medical University for Nationalities, Baise 533000, China
| | - Xiaoying Zhu
- Medical College, Guangxi University, Nanning 530004, China
- Clinical Pathological Diagnosis & Research Center, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, China
- Department of Tumor Pathology, The Key Laboratory of Molecular Pathology (Hepatobiliary Diseases) of Guangxi, Baise 533000, China
| | - Qinqin Long
- Clinical Pathological Diagnosis & Research Center, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, China
- Department of Tumor Pathology, The Key Laboratory of Molecular Pathology (Hepatobiliary Diseases) of Guangxi, Baise 533000, China
| | - Xueli Yi
- Center for Clinical Laboratory Diagnosis and Research, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, China
| | - Anni Yang
- Modern Industrial College of Biomedicine and Great Health, Youjiang Medical University for Nationalities, Baise 533000, China
- School of Medical Laboratory Sciences, Youjiang Medical University for Nationalities, Baise 533000, China
| | - Xidai Long
- Clinical Pathological Diagnosis & Research Center, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, China
- Department of Tumor Pathology, The Key Laboratory of Molecular Pathology (Hepatobiliary Diseases) of Guangxi, Baise 533000, China
- Correspondence: (X.L.); (D.C.)
| | - Demin Cao
- Clinical Pathological Diagnosis & Research Center, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, China
- Department of Tumor Pathology, The Key Laboratory of Molecular Pathology (Hepatobiliary Diseases) of Guangxi, Baise 533000, China
- Correspondence: (X.L.); (D.C.)
| |
Collapse
|
5
|
Liu X, Pang X, Wu Y, Wu Y, Shi Y, Zhang X, Chen Q. Synergistic Antibacterial Mechanism of Mannosylerythritol Lipid-A and Lactic Acid on Listeria monocytogenes Based on Transcriptomic Analysis. Foods 2022; 11:foods11172660. [PMID: 36076848 PMCID: PMC9455235 DOI: 10.3390/foods11172660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/26/2022] [Accepted: 08/28/2022] [Indexed: 11/21/2022] Open
Abstract
Mannosylerythritol lipids-A (MEL-A) is a novel biosurfactant with multiple biological effects. The synergistic antibacterial activity and mechanism of MEL-A and lactic acid (LA) against Listeria monocytogenes were investigated. The synergistic effect resulted in a significant increase in the antibacterial rate compared to LA treatment alone. Genome-wide transcriptomic analysis was applied to deeply investigate the synergistic antibacterial mechanism. Gene Ontology (GO) enrichment analysis showed that the synergy between MEL-A and LA affected many potential cellular responses, including the sugar phosphotransferase system, carbohydrate transport, and ribosomes. KEGG enrichment analysis showed that the PTS system and ribosome-related pathways were significantly enriched. In addition, synergistic treatment affected locomotion and membrane-related cellular responses in GO enrichment analysis and carbohydrate metabolism and amino acid metabolism pathways in KEGG enrichment analysis compared to LA treatment alone. The accuracy of the transcriptome analysis results was verified by qPCR (R2 = 0.9903). This study will provide new insights for the prevention and control of L. monocytogenes.
Collapse
Affiliation(s)
- Xiayu Liu
- Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, China
| | - Xinxin Pang
- Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, China
| | - Yansha Wu
- Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, China
| | - Yajing Wu
- Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, China
| | - Ying Shi
- Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, China
| | - Xinglin Zhang
- Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, China
- College of Agriculture and Forestry, Linyi University, Linyi 276005, China
| | - Qihe Chen
- Department of Food Science and Nutrition, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, China
- Correspondence: ; Tel.: +86-571-86984316
| |
Collapse
|
6
|
Cesinger MR, Schwardt NH, Halsey CR, Thomason MK, Reniere ML. Investigating the Roles of Listeria monocytogenes Peroxidases in Growth and Virulence. Microbiol Spectr 2021; 9:e0044021. [PMID: 34287055 PMCID: PMC8552690 DOI: 10.1128/spectrum.00440-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/23/2021] [Indexed: 11/25/2022] Open
Abstract
Bacteria have necessarily evolved a protective arsenal of proteins to contend with peroxides and other reactive oxygen species generated in aerobic environments. Listeria monocytogenes encounters an onslaught of peroxide both in the environment and during infection of the mammalian host, where it is the causative agent of the foodborne illness listeriosis. Despite the importance of peroxide for the immune response to bacterial infection, the strategy by which L. monocytogenes protects against peroxide toxicity has yet to be illuminated. Here, we investigated the expression and essentiality of all the peroxidase-encoding genes during L. monocytogenes growth in vitro and during infection of murine cells in tissue culture. We found that chdC and kat were required for aerobic growth in vitro, and fri and ahpA were each required for L. monocytogenes to survive acute peroxide stress. Despite increased expression of fri, ahpA, and kat during infection of macrophages, only fri proved necessary for cytosolic growth. In contrast, the proteins encoded by lmo0367, lmo0983, tpx, lmo1609, and ohrA were dispensable for aerobic growth, acute peroxide detoxification, and infection. Together, our results provide insight into the multifaceted L. monocytogenes peroxide detoxification strategy and demonstrate that L. monocytogenes encodes a functionally diverse set of peroxidase enzymes. IMPORTANCE Listeria monocytogenes is a facultative intracellular pathogen and the causative agent of the foodborne illness listeriosis. L. monocytogenes must contend with reactive oxygen species generated extracellularly during aerobic growth and intracellularly by the host immune system. However, the mechanisms by which L. monocytogenes defends against peroxide toxicity have not yet been defined. Here, we investigated the roles of each of the peroxidase-encoding genes in L. monocytogenes growth, peroxide stress response, and virulence in mammalian cells.
Collapse
Affiliation(s)
- Monica R. Cesinger
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Nicole H. Schwardt
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Cortney R. Halsey
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Maureen K. Thomason
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Michelle L. Reniere
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| |
Collapse
|
7
|
Birk MS, Ahmed-Begrich R, Tran S, Elsholz AKW, Frese CK, Charpentier E. Time-Resolved Proteome Analysis of Listeria monocytogenes during Infection Reveals the Role of the AAA+ Chaperone ClpC for Host Cell Adaptation. mSystems 2021; 6:e0021521. [PMID: 34342529 PMCID: PMC8407217 DOI: 10.1128/msystems.00215-21] [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: 02/24/2021] [Accepted: 07/14/2021] [Indexed: 12/13/2022] Open
Abstract
The cellular proteome comprises all proteins expressed at a given time and defines an organism's phenotype under specific growth conditions. The proteome is shaped and remodeled by both protein synthesis and protein degradation. Here, we developed a new method which combines metabolic and chemical isobaric peptide labeling to simultaneously determine the time-resolved protein decay and de novo synthesis in an intracellular human pathogen. We showcase this method by investigating the Listeria monocytogenes proteome in the presence and absence of the AAA+ chaperone protein ClpC. ClpC associates with the peptidase ClpP to form an ATP-dependent protease complex and has been shown to play a role in virulence development in L. monocytogenes. However, the mechanism by which ClpC is involved in the survival and proliferation of intracellular L. monocytogenes remains elusive. Employing this new method, we observed extensive proteome remodeling in L. monocytogenes upon interaction with the host, supporting the hypothesis that ClpC-dependent protein degradation is required to initiate bacterial adaptation mechanisms. We identified more than 100 putative ClpC target proteins through their stabilization in a clpC deletion strain. Beyond the identification of direct targets, we also observed indirect effects of the clpC deletion on the protein abundance in diverse cellular and metabolic pathways, such as iron acquisition and flagellar assembly. Overall, our data highlight the crucial role of ClpC for L. monocytogenes adaptation to the host environment through proteome remodeling. IMPORTANCE Survival and proliferation of pathogenic bacteria inside the host depend on their ability to adapt to the changing environment. Profiling the underlying changes on the bacterial proteome level during the infection process is important to gain a better understanding of the pathogenesis and the host-dependent adaptation processes. The cellular protein abundance is governed by the interplay between protein synthesis and decay. The direct readout of these events during infection can be accomplished using pulsed stable-isotope labeling by amino acids in cell culture (SILAC). Combining this approach with tandem-mass-tag (TMT) labeling enabled multiplexed and time-resolved bacterial proteome quantification during infection. Here, we applied this integrated approach to investigate protein turnover during the temporal progression of adaptation of the human pathogen L. monocytogenes to its host on a system-wide scale. Our experimental approach can easily be transferred to probe the proteome remodeling in other bacteria under a variety of perturbations.
Collapse
Affiliation(s)
- Marlène S. Birk
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| | | | - Stefan Tran
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| | | | | | | |
Collapse
|
8
|
Gray J, Chandry PS, Kaur M, Kocharunchitt C, Fanning S, Bowman JP, Fox EM. Colonisation dynamics of Listeria monocytogenes strains isolated from food production environments. Sci Rep 2021; 11:12195. [PMID: 34108547 PMCID: PMC8190317 DOI: 10.1038/s41598-021-91503-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/06/2021] [Indexed: 12/19/2022] Open
Abstract
Listeria monocytogenes is a ubiquitous bacterium capable of colonising and persisting within food production environments (FPEs) for many years, even decades. This ability to colonise, survive and persist within the FPEs can result in food product cross-contamination, including vulnerable products such as ready to eat food items. Various environmental and genetic elements are purported to be involved, with the ability to form biofilms being an important factor. In this study we examined various mechanisms which can influence colonisation in FPEs. The ability of isolates (n = 52) to attach and grow in biofilm was assessed, distinguishing slower biofilm formers from isolates forming biofilm more rapidly. These isolates were further assessed to determine if growth rate, exopolymeric substance production and/or the agr signalling propeptide influenced these dynamics and could promote persistence in conditions reflective of FPE. Despite no strong association with the above factors to a rapid colonisation phenotype, the global transcriptome suggested transport, energy production and metabolism genes were widely upregulated during the initial colonisation stages under nutrient limited conditions. However, the upregulation of the metabolism systems varied between isolates supporting the idea that L. monocytogenes ability to colonise the FPEs is strain-specific.
Collapse
Affiliation(s)
- Jessica Gray
- CSIRO Agriculture and Food, Werribee, VIC, Australia. .,Food Safety Centre, Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Hobart, TAS, Australia.
| | | | - Mandeep Kaur
- Biosciences and Food Technology, School of Science, RMIT University, Melbourne, VIC, Australia
| | - Chawalit Kocharunchitt
- Food Safety Centre, Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, D04 N2E5, Ireland.,Institute for Global Food Security, Queen's University Belfast, Chlorine Gardens, Belfast, BT5 6AG, UK
| | - John P Bowman
- Food Safety Centre, Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Edward M Fox
- CSIRO Agriculture and Food, Werribee, VIC, Australia. .,Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK.
| |
Collapse
|
9
|
Khasheii B, Mahmoodi P, Mohammadzadeh A. Siderophores: Importance in bacterial pathogenesis and applications in medicine and industry. Microbiol Res 2021; 250:126790. [PMID: 34098495 DOI: 10.1016/j.micres.2021.126790] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/14/2021] [Accepted: 05/24/2021] [Indexed: 12/21/2022]
Abstract
Iron is an essential element for all microorganisms. Siderophores are low-weight, high-affinity iron chelating molecules produced in response to iron deficiency by Gram-positive and Gram-negative bacteria which also known as essential virulence factors of bacteria. Several studies have indicated that defective production and/or function of these molecules as well as iron acquisition systems in pathogens are associated with a reduction in pathogenicity of bacteria. Because of their potential role in various biological pathways, siderophores have been received special attention as secondary metabolites. Siderophores can detect iron levels in a variety of environments with a biosensor function. In medicine, siderophores are used to deliver antibiotics (Trojan horse strategy) to resistant bacteria and to treat diseases such as cancer and malaria. In this review, we discuss the iron acquisition pathways in Gram-positive and -negative bacteria, importance of siderophore production in pathogenesis of bacteria, classification of siderophores, and main applications of siderophores in medicine and industry.
Collapse
Affiliation(s)
- Behnoush Khasheii
- Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran
| | - Pezhman Mahmoodi
- Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran.
| | - Abdolmajid Mohammadzadeh
- Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran
| |
Collapse
|
10
|
Characterization of the roles of activated charcoal and Chelex in the induction of PrfA regulon expression in complex medium. PLoS One 2021; 16:e0250989. [PMID: 33914817 PMCID: PMC8084165 DOI: 10.1371/journal.pone.0250989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 04/16/2021] [Indexed: 11/21/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes is able to survive across a wide range of intra- and extra-host environments by appropriately modulating gene expression patterns in response to different stimuli. Positive Regulatory Factor A (PrfA) is the major transcriptional regulator of virulence gene expression in L. monocytogenes. It has long been known that activated charcoal is required to induce the expression of PrfA-regulated genes in complex media, such as Brain Heart Infusion (BHI), but not in chemically defined media. In this study, we show that the expression of the PrfA-regulated hly, which encodes listeriolysin O, is induced 5- and 8-fold in L. monocytogenes cells grown in Chelex-treated BHI (Ch-BHI) and in the presence of activated charcoal (AC-BHI), respectively, relative to cells grown in BHI medium. Specifically, we show that metal ions present in BHI broth plays a role in the reduced expression of the PrfA regulon. In addition, we show that expression of hly is induced when the levels of bioavailable extra- or intercellular iron are reduced. L. monocytogenes cells grown Ch-BHI and AC-BHI media showed similar levels of resistance to the iron-activated antibiotic, streptonigrin, indicating that activated charcoal reduces the intracellular labile iron pool. Metal depletion and exogenously added glutathione contributed synergistically to PrfA-regulated gene expression since glutathione further increased hly expression in metal-depleted BHI but not in BHI medium. Analyses of transcriptional reporter fusion expression patterns revealed that genes in the PrfA regulon are differentially expressed in response to metal depletion, metal excess and exogenous glutathione. Our results suggest that metal ion abundance plays a role in modulating expression of PrfA-regulated virulence genes in L. monocytogenes.
Collapse
|
11
|
Joshi B, Singh B, Nadeem A, Askarian F, Wai SN, Johannessen M, Hegstad K. Transcriptome Profiling of Staphylococcus aureus Associated Extracellular Vesicles Reveals Presence of Small RNA-Cargo. Front Mol Biosci 2021; 7:566207. [PMID: 33521050 PMCID: PMC7838569 DOI: 10.3389/fmolb.2020.566207] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 12/14/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial extracellular vesicles (EVs) have a vital role in bacterial pathogenesis. However, to date, the small RNA-cargo of EVs released by the opportunistic pathogen Staphylococcus aureus has not been characterized. Here, we shed light on the association of small RNAs with EVs secreted by S. aureus MSSA476 cultured in iron-depleted bacteriologic media supplemented with a subinhibitory dosage of vancomycin to mimic infection condition. Confocal microscopy analysis on intact RNase-treated EVs indicated that RNA is associated with EV particles. Transcriptomic followed by bioinformatics analysis of EV-associated RNA revealed the presence of potential gene regulatory small RNAs and high levels of tRNAs. Among the EV-associated enriched small RNAs were SsrA, RsaC and RNAIII. Our finding invites new insights into the potential role of EV-associated RNA as a modulator of host-pathogen interaction.
Collapse
Affiliation(s)
- Bishnu Joshi
- Department of Medical Biology, Research Group for Host-Microbe Interactions, UiT The Arctic University of Norway, Tromsø, Norway
| | - Bhupender Singh
- Department of Medical Biology, Research Group for Host-Microbe Interactions, UiT The Arctic University of Norway, Tromsø, Norway
| | - Aftab Nadeem
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Fatemeh Askarian
- Department of Medical Biology, Research Group for Host-Microbe Interactions, UiT The Arctic University of Norway, Tromsø, Norway.,Faculty of Chemistry, Biotechnology and Food Science, The Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Sun Nyunt Wai
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Mona Johannessen
- Department of Medical Biology, Research Group for Host-Microbe Interactions, UiT The Arctic University of Norway, Tromsø, Norway
| | - Kristin Hegstad
- Department of Medical Biology, Research Group for Host-Microbe Interactions, UiT The Arctic University of Norway, Tromsø, Norway.,Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North-Norway, Tromsø, Norway
| |
Collapse
|
12
|
Stincone P, Comerlato CB, Brandelli A. Proteomic analysis of Listeria monocytogenes exposed to free and nanostructured antimicrobial lipopeptides. Mol Omics 2021; 17:426-437. [PMID: 33735358 DOI: 10.1039/d0mo00178c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this work, the effect of antimicrobial lipopeptide P34 on Listeria monocytogenes was evaluated for the first time through a proteomics approach. Bacteria were treated with sub-lethal doses of peptide P34 (F-P34) and P34 encapsulated into nanoliposomes (N-P34), while empty nanoliposomes (NE) and fresh buffer were used as controls. The proteomic analysis allowed the detection of one group of proteins commonly differentially represented in response to free and encapsulated P34 exposure. A second group of proteins was found to be exclusively differentially represented after exposure with encapsulated P34 only. The antimicrobial peptide P34 caused a significant downregulation of proteins associated with the transport of manganese and the over-representation of proteins related with iron transport in L. monocytogenes. In addition, reduction of stress tolerance proteins related to the σB and VirR regulons, together with the modulation of phosphoenolpyruvate phosphotransferase systems (PTS) for sugar transport were observed. The sugar and oligopeptide transporters regulated by antimicrobial action may influence the key virulence factor PrfA, reducing the pathogenicity of this microorganism.
Collapse
Affiliation(s)
- Paolo Stincone
- Laboratório de Bioquímica e Microbiologia Aplicada, Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, Brazil.
| | | | | |
Collapse
|
13
|
Bacillus subtilis Fur Is a Transcriptional Activator for the PerR-Repressed pfeT Gene, Encoding an Iron Efflux Pump. J Bacteriol 2020; 202:JB.00697-19. [PMID: 31988078 DOI: 10.1128/jb.00697-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/23/2020] [Indexed: 12/30/2022] Open
Abstract
The physiological relevance of bacterial iron efflux has only recently been appreciated. The Bacillus subtilis P1B4-type ATPase PfeT (peroxide-induced ferrous efflux transporter) was one of the first iron efflux pumps to be characterized, and cells lacking pfeT accumulate high levels of intracellular iron. The pfeT promoter region has binding sites for both PerR, a peroxide-sensing Fur-family metalloregulator, and the ferric uptake repressor Fur. Both Fur and PerR bind DNA with Fe(II) as a cofactor. While reaction of PerR-Fe(II) with peroxide can account for the induction of pfeT under oxidative stress, binding of Fur-Fe(II) would be expected to lead to repression, which is inconsistent with the known role of PfeT as an iron efflux protein. Here, we show that expression of pfeT is repressed by PerR, as anticipated, and induced by Fur in response to Fe(II). Activation by Fur is mediated both by antagonism of the PerR repressor and by direct transcriptional activation, as confirmed using in vitro transcription assays. A similar mechanism of regulation can explain the iron induction of the Listeria monocytogenes PfeT ortholog and virulence factor, FrvA. Mutational studies support a model in which Fur activation involves regions both upstream and downstream of the pfeT promoter, and Fur and PerR have overlapping recognition of a shared regulatory element in this complex promoter region. This work demonstrates that B. subtilis Fur can function as an iron-dependent activator of transcription.IMPORTANCE Iron homeostasis plays a key role at the host-pathogen interface during the process of infection. Bacterial growth restriction resulting from host-imposed iron starvation (nutritional immunity) highlights the importance of iron import during pathogenesis. Conversely, bacterial iron efflux pumps function as virulence factors in several systems. The requirement for iron efflux in pathogens such as Listeria monocytogenes, Streptococcus pyogenes, and Mycobacterium tuberculosis suggests that both import and efflux are needed for cells to successfully navigate rapidly changing levels of iron availability in the host. Here, we provide insight into how iron efflux genes are controlled, an aspect of bacterial iron homeostasis relevant to infectious disease processes.
Collapse
|
14
|
Dos Santos PT, Larsen PT, Menendez-Gil P, Lillebæk EMS, Kallipolitis BH. Listeria monocytogenes Relies on the Heme-Regulated Transporter hrtAB to Resist Heme Toxicity and Uses Heme as a Signal to Induce Transcription of lmo1634, Encoding Listeria Adhesion Protein. Front Microbiol 2018; 9:3090. [PMID: 30619169 PMCID: PMC6305404 DOI: 10.3389/fmicb.2018.03090] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/29/2018] [Indexed: 01/29/2023] Open
Abstract
For pathogenic bacteria, host-derived heme represents an important metabolic cofactor and a source for iron. However, high levels of heme are toxic to bacteria. We have previously shown that excess heme has a growth-inhibitory effect on the Gram-positive foodborne pathogen Listeria monocytogenes, and we have learned that the LhrC1-5 family of small RNAs, together with the two-component system (TCS) LisRK, play a role in the adaptation of L. monocytogenes to heme stress conditions. However, a broader knowledge on how this pathogen responds to heme toxicity is still lacking. Here, we analyzed the global transcriptomic response of L. monocytogenes to heme stress. We found that the response of L. monocytogenes to excess heme is multifaceted, involving various strategies acting to minimize the toxic effects of heme. For example, heme exposure triggers the SOS response that deals with DNA damage. In parallel, L. monocytogenes shuts down the transcription of genes involved in heme/iron uptake and utilization. Furthermore, heme stress resulted in a massive increase in the transcription of a putative heme detoxification system, hrtAB, which is highly conserved in Gram-positive bacteria. As expected, we found that the TCS HssRS is required for heme-mediated induction of hrtAB and that a functional heme efflux system is essential for L. monocytogenes to resist heme toxicity. Curiously, the most highly up-regulated gene upon heme stress was lmo1634, encoding the Listeria adhesion protein, LAP, which acts to promote the translocation of L. monocytogenes across the intestinal barrier. Additionally, LAP is predicted to act as a bifunctional acetaldehyde-CoA/alcohol dehydrogenase. Surprisingly, a mutant lacking lmo1634 grows well under heme stress conditions, showing that LAP is not required for L. monocytogenes to resist heme toxicity. Likewise, a functional ResDE TCS, which contributes to heme-mediated expression of lmo1634, is not required for the adaptation of L. monocytogenes to heme stress conditions. Collectively, this study provides novel insights into the strategies employed by L. monocytogenes to resist heme toxicity. Our findings indicate that L. monocytogenes is using heme as a host-derived signaling molecule to control the expression of its virulence genes, as exemplified by lmo1634.
Collapse
Affiliation(s)
| | - Pernille Tholund Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Pilar Menendez-Gil
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | | | | |
Collapse
|
15
|
Dos Santos PT, Menendez-Gil P, Sabharwal D, Christensen JH, Brunhede MZ, Lillebæk EMS, Kallipolitis BH. The Small Regulatory RNAs LhrC1-5 Contribute to the Response of Listeria monocytogenes to Heme Toxicity. Front Microbiol 2018; 9:599. [PMID: 29636750 PMCID: PMC5880928 DOI: 10.3389/fmicb.2018.00599] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/15/2018] [Indexed: 11/29/2022] Open
Abstract
The LhrC family of small regulatory RNAs (sRNAs) is known to be induced when the foodborne pathogen Listeria monocytogenes is exposed to infection-relevant conditions, such as human blood. Here we demonstrate that excess heme, the core component of hemoglobin in blood, leads to a strong induction of the LhrC family members LhrC1–5. The heme-dependent activation of lhrC1–5 relies on the response regulator LisR, which is known to play a role in virulence and stress tolerance. Importantly, our studies revealed that LhrC1–5 and LisR contribute to the adaptation of L. monocytogenes to excess heme. Regarding the regulatory function of the sRNAs, we demonstrate that LhrC1–5 act to down-regulate the expression of known LhrC target genes under heme-rich conditions: oppA, tcsA, and lapB, encoding surface exposed proteins with virulence functions. These genes were originally identified as targets for LhrC-mediated control under cell envelope stress conditions, suggesting a link between the response to heme toxicity and cell envelope stress in L. monocytogenes. We also investigated the role of LhrC1–5 in controlling the expression of genes involved in heme uptake and utilization: lmo2186 and lmo2185, encoding the heme-binding proteins Hbp1 and Hbp2, respectively, and lmo0484, encoding a heme oxygenase-like protein. Using in vitro binding assays, we demonstrated that the LhrC family member LhrC4 interacts with mRNAs encoded from lmo2186, lmo2185, and lmo0484. For lmo0484, we furthermore show that LhrC4 uses a CU-rich loop for basepairing to the AG-rich Shine–Dalgarno region of the mRNA. The presence of a link between the response to heme toxicity and cell envelope stress was further underlined by the observation that LhrC1–5 down-regulate the expression of lmo0484 in response to the cell wall-acting antibiotic cefuroxime. Collectively, this study suggests a role for the LisR-regulated sRNAs LhrC1–5 in a coordinated response to excess heme and cell envelope stress in L. monocytogenes.
Collapse
Affiliation(s)
- Patrícia T Dos Santos
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Pilar Menendez-Gil
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Dharmesh Sabharwal
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Jens-Henrik Christensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Maja Z Brunhede
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Eva M S Lillebæk
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Birgitte H Kallipolitis
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
16
|
Vivant AL, Desneux J, Pourcher AM, Piveteau P. Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Lagoon and Soil Matrices Associated with a Piggery Environment: Comparison of Expression Profiles. Front Microbiol 2017; 8:1811. [PMID: 29018416 PMCID: PMC5623016 DOI: 10.3389/fmicb.2017.01811] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 09/05/2017] [Indexed: 12/20/2022] Open
Abstract
Understanding how Listeria monocytogenes, the causative agent of listeriosis, adapts to the environment is crucial. Adaptation to new matrices requires regulation of gene expression. To determine how the pathogen adapts to lagoon effluent and soil, two matrices where L. monocytogenes has been isolated, we compared the transcriptomes of L. monocytogenes CIP 110868 20 min and 24 h after its transfer to effluent and soil extract. Results showed major variations in the transcriptome of L. monocytogenes in the lagoon effluent but only minor modifications in the soil. In both the lagoon effluent and in the soil, genes involved in mobility and chemotaxis and in the transport of carbohydrates were the most frequently represented in the set of genes with higher transcript levels, and genes with phage-related functions were the most represented in the set of genes with lower transcript levels. A modification of the cell envelop was only found in the lagoon environment. Finally, the differential analysis included a large proportion of regulators, regulons, and ncRNAs.
Collapse
Affiliation(s)
- Anne-Laure Vivant
- UR OPAALE, IRSTEA, Rennes, France
- Université Bretagne Loire, Rennes, France
| | - Jeremy Desneux
- UR OPAALE, IRSTEA, Rennes, France
- Université Bretagne Loire, Rennes, France
| | | | - Pascal Piveteau
- Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique, Université Bourgogne Franche-Comté, Dijon, France
| |
Collapse
|
17
|
Guo Y, Hu D, Guo J, Li X, Guo J, Wang X, Xiao Y, Jin H, Liu M, Li Z, Bi D, Zhou Z. The Role of the Regulator Fur in Gene Regulation and Virulence of Riemerella anatipestifer Assessed Using an Unmarked Gene Deletion System. Front Cell Infect Microbiol 2017; 7:382. [PMID: 28971067 PMCID: PMC5609570 DOI: 10.3389/fcimb.2017.00382] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/09/2017] [Indexed: 11/29/2022] Open
Abstract
Riemerella anatipestifer, an avian pathogen, has resulted in enormous economic losses to the duck industry globally. Notwithstanding, little is known regarding the physiological, pathogenic and virulence mechanisms of Riemerella anatipestifer (RA) infection. However, the role of Ferric uptake regulator (Fur) in the virulence of R. anatipestifer has not, to date, been demonstrated. Using a genetic approach, unmarked gene deletion system, we evaluated the function of fur gene in the virulence of R. anatipestifer. For this purpose, we constructed a suicide vector containing pheS as a counter selectable marker for unmarked deletion of fur gene to investigate its role in the virulence. After successful transformation of the newly constructed vector, a mutant strain was characterized for genes regulated by iron and Fur using RNA-sequencing and a comparison was made between wild type and mutant strains in both iron restricted and enriched conditions. RNA-seq analysis of the mutant strain in a restricted iron environment showed the downregulation and upregulation of genes which were involved in either important metabolic pathways, transport processes, growth or cell membrane synthesis. Electrophoretic mobility shift assay was performed to identify the putative sequences recognized by Fur. The putative Fur-box sequence was 5′-GATAATGATAATCATTATC-3′. Lastly, the median lethal dose and histopathological investigations of animal tissues also illustrated mild pathological lesions produced by the mutant strain as compared to the wild type RA strain, hence showing declined virulence. Conclusively, an unmarked gene deletion system was successfully developed for RA and the role of the fur gene in virulence was explored comprehensively.
Collapse
Affiliation(s)
- Yunqing Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Di Hu
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Jie Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Xiaowen Li
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Jinyue Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Xiliang Wang
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Yuncai Xiao
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Hui Jin
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
| | - Mei Liu
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Zili Li
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Dingren Bi
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
| | - Zutao Zhou
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| |
Collapse
|
18
|
Abstract
Bacteria require iron for growth, with only a few reported exceptions. In many environments, iron is a limiting nutrient for growth and high affinity uptake systems play a central role in iron homeostasis. However, iron can also be detrimental to cells when it is present in excess, particularly under aerobic conditions where its participation in Fenton chemistry generates highly reactive hydroxyl radicals. Recent results have revealed a critical role for iron efflux transporters in protecting bacteria from iron intoxication. Systems that efflux iron are widely distributed amongst bacteria and fall into several categories: P1B-type ATPases, cation diffusion facilitator (CDF) proteins, major facilitator superfamily (MFS) proteins, and membrane bound ferritin-like proteins. Here, we review the emerging role of iron export in both iron homeostasis and as part of the adaptive response to oxidative stress.
Collapse
Affiliation(s)
- Hualiang Pi
- Department of Microbiology, Cornell University, Ithaca, NY 14853-8101, USA.
| | | |
Collapse
|
19
|
Abstract
Iron is an essential micronutrient for both microbes and humans alike. For well over half a century we have known that this element, in particular, plays a pivotal role in health and disease and, most especially, in shaping host-pathogen interactions. Intracellular iron concentrations serve as a critical signal in regulating the expression not only of high-affinity iron acquisition systems in bacteria, but also of toxins and other noted virulence factors produced by some major human pathogens. While we now are aware of many strategies that the host has devised to sequester iron from invading microbes, there are as many if not more sophisticated mechanisms by which successful pathogens overcome nutritional immunity imposed by the host. This review discusses some of the essential components of iron sequestration and scavenging mechanisms of the host, as well as representative Gram-negative and Gram-positive pathogens, and highlights recent advances in the field. Last, we address how the iron acquisition strategies of pathogenic bacteria may be exploited for the development of novel prophylactics or antimicrobials.
Collapse
|
20
|
Brenz Y, Ohnezeit D, Winther-Larsen HC, Hagedorn M. Nramp1 and NrampB Contribute to Resistance against Francisella in Dictyostelium. Front Cell Infect Microbiol 2017; 7:282. [PMID: 28680861 PMCID: PMC5478718 DOI: 10.3389/fcimb.2017.00282] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/09/2017] [Indexed: 12/16/2022] Open
Abstract
The Francisella genus comprises highly pathogenic bacteria that can cause fatal disease in their vertebrate and invertebrate hosts including humans. In general, Francisella growth depends on iron availability, hence, iron homeostasis must be tightly regulated during Francisella infection. We used the system of the professional phagocyte Dictyostelium and the fish pathogen F. noatunensis subsp. noatunensis (F.n.n.) to investigate the role of the host cell iron transporters Nramp (natural resistance associated macrophage proteins) during Francisella infection. Like its mammalian ortholog, Dictyostelium Nramp1 transports iron from the phagosome into the cytosol, whereas the paralog NrampB is located on the contractile vacuole and controls, together with Nramp1, the cellular iron homeostasis. In Dictyostelium, Nramp1 localized to the F.n.n.-phagosome but disappeared from the compartment dependent on the presence of IglC, an established Francisella virulence factor. In the absence of Nramp transporters the bacteria translocated more efficiently from the phagosome into the host cell cytosol, its replicative niche. Increased escape rates coincided with increased proteolytic activity in bead-containing phagosomes indicating a role of the Nramp transporters for phagosomal maturation. In the nramp mutants, a higher bacterial load was observed in the replicative phase compared to wild-type host cells. Upon bacterial access to the cytosol of wt cells, mRNA levels of bacterial iron uptake factors were transiently upregulated. Decreased iron levels in the nramp mutants were compensated by a prolonged upregulation of the iron scavenging system. These results show that Nramps contribute to host cell immunity against Francisella infection by influencing the translocation efficiency from the phagosome to the cytosol but not by restricting access to nutritional iron in the cytosol.
Collapse
Affiliation(s)
- Yannick Brenz
- Department of Parasitology, Bernhard Nocht Institute for Tropical MedicineHamburg, Germany
| | - Denise Ohnezeit
- Institute for Medical Microbiology, Hygiene and Virology, University Medical Center Hamburg-EppendorfHamburg, Germany
| | - Hanne C Winther-Larsen
- Centre for Integrative Microbial Evolution and Department of Pharmaceutical Biosciences, University of OsloOslo, Norway
| | - Monica Hagedorn
- Department of Life Sciences and Chemistry, Jacobs UniversityBremen, Germany
| |
Collapse
|
21
|
Tronnet S, Garcie C, Brachmann AO, Piel J, Oswald E, Martin P. High iron supply inhibits the synthesis of the genotoxin colibactin by pathogenic Escherichia coli through a non-canonical Fur/RyhB-mediated pathway. Pathog Dis 2017. [DOI: 10.1093/femspd/ftx066] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Sophie Tronnet
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, 31024 Toulouse, France
- Université Toulouse III Paul Sabatier, 31000 Toulouse, France
| | - Christophe Garcie
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, 31024 Toulouse, France
- Université Toulouse III Paul Sabatier, 31000 Toulouse, France
- CHU Toulouse, Service de Bactériologie-Hygiène, 31000 Toulouse, France
| | - Alexander O. Brachmann
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH), 8093 Zurich, Switzerland
| | - Jörn Piel
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH), 8093 Zurich, Switzerland
| | - Eric Oswald
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, 31024 Toulouse, France
- Université Toulouse III Paul Sabatier, 31000 Toulouse, France
- CHU Toulouse, Service de Bactériologie-Hygiène, 31000 Toulouse, France
| | - Patricia Martin
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, 31024 Toulouse, France
- Université Toulouse III Paul Sabatier, 31000 Toulouse, France
- CHU Toulouse, Service de Bactériologie-Hygiène, 31000 Toulouse, France
| |
Collapse
|
22
|
Pieta L, Escudero FLG, Jacobus AP, Cheiran KP, Gross J, Moya MLE, Soares GLG, Margis R, Frazzon APG, Frazzon J. Comparative transcriptomic analysis of Listeria monocytogenes reveals upregulation of stress genes and downregulation of virulence genes in response to essential oil extracted from Baccharis psiadioides. ANN MICROBIOL 2017. [DOI: 10.1007/s13213-017-1277-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
23
|
Pi H, Patel SJ, Argüello JM, Helmann JD. The Listeria monocytogenes Fur-regulated virulence protein FrvA is an Fe(II) efflux P1B4 -type ATPase. Mol Microbiol 2016; 100:1066-79. [PMID: 26946370 DOI: 10.1111/mmi.13368] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2016] [Indexed: 01/07/2023]
Abstract
Listeria monocytogenes FrvA (Lmo0641) is critical for virulence in the mouse model and is an ortholog of the Bacillus subtilis Fur- and PerR-regulated Fe(II) efflux P1B4 -type ATPase PfeT. Previously, FrvA was suggested to protect against heme toxicity. Here, we demonstrate that an frvA mutant is sensitive to iron intoxication, but not to other metals. Expression of frvA is induced by high iron and this induction requires Fur. FrvA functions in vitro as a divalent cation specific ATPase most strongly activated by ferrous iron. When expressed in B. subtilis, FrvA increases resistance to iron both in wild-type and in a pfeT null strain. FrvA is a high affinity Fe(II) exporter and its induction imposes severe iron limitation in B. subtilis resulting in derepression of both Fur- and PerR-regulated genes. FrvA also recognizes Co(II) and Zn(II) as substrates and can complement B. subtilis strains defective in the endogenous export systems for these cations. Building on these results, we conclude that FrvA functions in the efflux of Fe(II), and not heme during listerial infection.
Collapse
Affiliation(s)
- Hualiang Pi
- Department of Microbiology, Cornell University, Ithaca, NY, 14853, USA
| | - Sarju J Patel
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - John D Helmann
- Department of Microbiology, Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
24
|
Abstract
Twin-arginine protein translocation systems (Tat) translocate fully folded and co-factor-containing proteins across biological membranes. In this review, we focus on the Tat pathway of Gram-positive bacteria. The minimal Tat pathway is composed of two components, namely a TatA and TatC pair, which are often complemented with additional TatA-like proteins. We provide overviews of our current understanding of Tat pathway composition and mechanistic aspects related to Tat-dependent cargo protein translocation. This includes Tat pathway flexibility, requirements for the correct folding and incorporation of co-factors in cargo proteins and the functions of known cargo proteins. Tat pathways of several Gram-positive bacteria are discussed in detail, with emphasis on the Tat pathway of Bacillus subtilis. We discuss both shared and unique features of the different Gram-positive bacterial Tat pathways. Lastly, we highlight topics for future research on Tat, including the development of this protein transport pathway for the biotechnological secretion of high-value proteins and its potential applicability as an antimicrobial drug target in pathogens.
Collapse
Affiliation(s)
- Vivianne J Goosens
- MRC Centre for Molecular Bacteriology and Infection, Section of Microbiology, Imperial College London, London, SW7 2AZ, UK
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700, RB, Groningen, The Netherlands.
| |
Collapse
|
25
|
Vivant AL, Garmyn D, Gal L, Hartmann A, Piveteau P. Survival of Listeria monocytogenes in Soil Requires AgrA-Mediated Regulation. Appl Environ Microbiol 2015; 81:5073-84. [PMID: 26002901 PMCID: PMC4495223 DOI: 10.1128/aem.04134-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 05/12/2015] [Indexed: 11/20/2022] Open
Abstract
In a recent paper, we demonstrated that inactivation of the Agr system affects the patterns of survival of Listeria monocytogenes (A.-L. Vivant, D. Garmyn, L. Gal, and P. Piveteau, Front Cell Infect Microbiol 4:160, http://dx.doi.org/10.3389/fcimb.2014.00160). In this study, we investigated whether the Agr-mediated response is triggered during adaptation in soil, and we compared survival patterns in a set of 10 soils. The fate of the parental strain L. monocytogenes L9 (a rifampin-resistant mutant of L. monocytogenes EGD-e) and that of a ΔagrA deletion mutant were compared in a collection of 10 soil microcosms. The ΔagrA mutant displayed significantly reduced survival in these biotic soil microcosms, and differential transcriptome analyses showed large alterations of the transcriptome when AgrA was not functional, while the variations in the transcriptomes between the wild type and the ΔagrA deletion mutant were modest under abiotic conditions. Indeed, in biotic soil environments, 578 protein-coding genes and an extensive repertoire of noncoding RNAs (ncRNAs) were differentially transcribed. The transcription of genes coding for proteins involved in cell envelope and cellular processes, including the phosphotransferase system and ABC transporters, and proteins involved in resistance to antimicrobial peptides was affected. Under sterilized soil conditions, the differences were limited to 86 genes and 29 ncRNAs. These results suggest that the response regulator AgrA of the Agr communication system plays important roles during the saprophytic life of L. monocytogenes in soil.
Collapse
Affiliation(s)
- Anne-Laure Vivant
- Université de Bourgogne, UMR1347 Agroécologie, Dijon, France INRA, UMR1347 Agroécologie, Dijon, France
| | - Dominique Garmyn
- Université de Bourgogne, UMR1347 Agroécologie, Dijon, France INRA, UMR1347 Agroécologie, Dijon, France
| | - Laurent Gal
- INRA, UMR1347 Agroécologie, Dijon, France AgroSup Dijon, UMR1347 Agroécologie, Dijon, France
| | - Alain Hartmann
- Université de Bourgogne, UMR1347 Agroécologie, Dijon, France INRA, UMR1347 Agroécologie, Dijon, France
| | - Pascal Piveteau
- Université de Bourgogne, UMR1347 Agroécologie, Dijon, France INRA, UMR1347 Agroécologie, Dijon, France
| |
Collapse
|
26
|
Pulgar R, Hödar C, Travisany D, Zuñiga A, Domínguez C, Maass A, González M, Cambiazo V. Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system. BMC Genomics 2015; 16:495. [PMID: 26141111 PMCID: PMC4490697 DOI: 10.1186/s12864-015-1716-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 06/23/2015] [Indexed: 01/24/2023] Open
Abstract
Background Piscirickettsiosis or Salmonid Rickettsial Septicaemia (SRS) is a bacterial disease that has a major economic impact on the Chilean salmon farming industry. Despite the fact that Piscirickettsia salmonis has been recognized as a major fish pathogen for over 20 years, the molecular strategies underlying the fish response to infection and the bacterial mechanisms of pathogenesis are poorly understood. We analysed and compared the head kidney transcriptional response of Atlantic salmon (Salmo salar) families with different levels of susceptibility to P. salmonis infection in order to reveal mechanisms that might confer infection resistance. Results We ranked forty full-sibling Atlantic salmon families according to accumulated mortality after a challenge with P. salmonis and selected the families with the lowest and highest cumulative mortalities for microarray gene expression analysis. A comparison of the response to P. salmonis infection between low and high susceptibility groups identified biological processes presumably involved in natural resistance to the pathogen. In particular, expression changes of genes linked to cellular iron depletion, as well as low iron content and bacterial load in the head kidney of fish from low susceptibility families, suggest that iron-deprivation is an innate immunity defence mechanism against P. salmonis. To complement these results, we predicted a set of iron acquisition genes from the P. salmonis genome. Identification of putative Fur boxes and expression of the genes under iron-depleted conditions revealed that most of these genes form part of the Fur regulon of P. salmonis. Conclusions This study revealed, for the first time, differences in the transcriptional response to P. salmonis infection among Atlantic salmon families with varied levels of susceptibility to the infection. These differences correlated with changes in the abundance of transcripts encoding proteins directly and indirectly involved in the immune response; changes that highlighted the role of nutritional immunity through iron deprivation in host defence mechanisms against P. salmonis. Additionally, we found that P. salmonis has several mechanisms for iron acquisition, suggesting that this bacterium can obtain iron from different sources, including ferric iron through capturing endogenous and exogenous siderophores and ferrous iron. Our results contribute to determining the underlying resistance mechanisms of Atlantic salmon to P. salmonis infection and to identifying future treatment strategies. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1716-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Rodrigo Pulgar
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago, Chile.
| | - Christian Hödar
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago, Chile. .,Fondap Center for Genome Regulation, Av. Blanco Encalada 2085, Santiago, Chile.
| | - Dante Travisany
- Fondap Center for Genome Regulation, Av. Blanco Encalada 2085, Santiago, Chile. .,Center for Mathematical Modeling and Department of Mathematical Engineering, Av. Beauchef 851, Santiago, Chile.
| | - Alejandro Zuñiga
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago, Chile.
| | - Calixto Domínguez
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago, Chile.
| | - Alejandro Maass
- Fondap Center for Genome Regulation, Av. Blanco Encalada 2085, Santiago, Chile. .,Center for Mathematical Modeling and Department of Mathematical Engineering, Av. Beauchef 851, Santiago, Chile.
| | - Mauricio González
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago, Chile. .,Fondap Center for Genome Regulation, Av. Blanco Encalada 2085, Santiago, Chile.
| | - Verónica Cambiazo
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago, Chile. .,Fondap Center for Genome Regulation, Av. Blanco Encalada 2085, Santiago, Chile.
| |
Collapse
|
27
|
Sheldon JR, Heinrichs DE. Recent developments in understanding the iron acquisition strategies of gram positive pathogens. FEMS Microbiol Rev 2015; 39:592-630. [DOI: 10.1093/femsre/fuv009] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2015] [Indexed: 12/26/2022] Open
|
28
|
Lechowicz J, Krawczyk-Balska A. An update on the transport and metabolism of iron in Listeria monocytogenes: the role of proteins involved in pathogenicity. Biometals 2015; 28:587-603. [PMID: 25820385 PMCID: PMC4481299 DOI: 10.1007/s10534-015-9849-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 03/17/2015] [Indexed: 12/21/2022]
Abstract
Listeria monocytogenes is a Gram-positive bacterium that causes a rare but severe human disease with high mortality rate. The microorganism is widespread in the natural environment where it shows a saprophytic lifestyle. In the human body it infects many different cell types, where it lives intracellularly, however it may also temporarily live extracellularly. The ability to survive and grow in such diverse niches suggests that this bacterium has a wide range of mechanisms for both the acquisition of various sources of iron and effective management of this microelement. In this review, data about the mechanisms of transport, metabolism and regulation of iron, including recent findings in these areas, are summarized with focus on the importance of these mechanisms for the virulence of L. monocytogenes. These data indicate the key role of haem transport and maintenance of intracellular iron homeostasis for the pathogenesis of L. monocytogenes. Furthermore, some of the proteins involved in iron homeostasis like Fri and FrvA seem to deserve special attention due to their potential use in the development of new therapeutic antilisterial strategies.
Collapse
Affiliation(s)
- Justyna Lechowicz
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | | |
Collapse
|
29
|
Tiwari KB, Birlingmair J, Wilkinson BJ, Jayaswal RK. Role of the twin-arginine translocase (tat) system in iron uptake in Listeria monocytogenes. Microbiology (Reading) 2015; 161:264-271. [DOI: 10.1099/mic.0.083642-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Kiran B. Tiwari
- School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Jacob Birlingmair
- School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Brian J. Wilkinson
- School of Biological Sciences, Illinois State University, Normal, IL, USA
| | | |
Collapse
|
30
|
Mata MM, da Silva WP, Wilson R, Lowe E, Bowman JP. Attached and planktonic Listeria monocytogenes global proteomic responses and associated influence of strain genetics and temperature. J Proteome Res 2015; 14:1161-73. [PMID: 25516393 DOI: 10.1021/pr501114e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Contamination of industrial and domestic food usage environments by the attachement of bacterial food-borne pathogen Listeria monocytogenes has public health and economic implications. Comprehensive proteomics experiments using label-free liquid chromatography/tandem mass spectrometry were used to compare the proteomes of two different L. monocytogenes strains (Siliken_1/2c and F2365_4b), which show very different capacities to attach to surfaces. Growth temperature and strain type were highly influential on the proteomes in both attached and planktonic cells. On the basis of the proteomic data, it is highly unlikely that specific surface proteins play a direct role in adherence to inanimate surfaces. Instead, strain-dependent responses related to cell envelope polymer biosynthesis and stress response regulation likely contribute to a different ability to attach and also to survive external stressors. Collectively, the divergent proteome-level responses observed define strain- and growth-temperature-dependent differences relevant to attachment efficacy, highlight relevant proteins involved in stress protection in attached cells, and suggest that strain differences and growth conditions are important in relation to environmental persistence.
Collapse
Affiliation(s)
- Marcia M Mata
- Science and Agroindustrial Technology Department, Federal University of Pelotas , Pelotas 96160-000, Brazil
| | | | | | | | | |
Collapse
|
31
|
Halbedel S, Reiss S, Hahn B, Albrecht D, Mannala GK, Chakraborty T, Hain T, Engelmann S, Flieger A. A systematic proteomic analysis of Listeria monocytogenes house-keeping protein secretion systems. Mol Cell Proteomics 2014; 13:3063-81. [PMID: 25056936 DOI: 10.1074/mcp.m114.041327] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Listeria monocytogenes is a firmicute bacterium causing serious infections in humans upon consumption of contaminated food. Most of its virulence factors are secretory proteins either released to the medium or attached to the bacterial surface. L. monocytogenes encodes at least six different protein secretion pathways. Although great efforts have been made in the past to predict secretory proteins and their secretion routes using bioinformatics, experimental evidence is lacking for most secretion systems. Therefore, we constructed mutants in the main housekeeping protein secretion systems, which are the Sec-dependent transport, the YidC membrane insertases SpoIIIJ and YqjG, as well as the twin-arginine pathway, and analyzed their secretion and virulence defects. Our results demonstrate that Sec-dependent secretion and membrane insertion of proteins via YidC proteins are essential for viability of L. monocytogenes. Depletion of SecA or YidC activity severely affected protein secretion, whereas loss of the Tat-pathway was without any effect on secretion, viability, and virulence. Two-dimensional gel electrophoresis combined with protein identification by mass spectrometry revealed that secretion of many virulence factors and of enzymes synthesizing and degrading the cell wall depends on the SecA route. This finding was confirmed by SecA inhibition experiments using sodium azide. Analysis of secretion of substrates typically dependent on the accessory SecA2 ATPase in wild type and azide resistant mutants of L. monocytogenes revealed for the first time that SecA2-dependent protein secretion also requires the ATPase activity of the house-keeping SecA protein.
Collapse
Affiliation(s)
- Sven Halbedel
- From the ‡Robert Koch Institute, FG11 - Division of Enteropathogenic Bacteria and Legionella, Burgstrasse 37, 38855 Wernigerode, Germany;
| | - Swantje Reiss
- §Institute of Microbiology, University of Greifswald, F.-L.-Jahn-Strasse 15, 17487 Greifswald, Germany
| | - Birgit Hahn
- From the ‡Robert Koch Institute, FG11 - Division of Enteropathogenic Bacteria and Legionella, Burgstrasse 37, 38855 Wernigerode, Germany
| | - Dirk Albrecht
- §Institute of Microbiology, University of Greifswald, F.-L.-Jahn-Strasse 15, 17487 Greifswald, Germany
| | - Gopala Krishna Mannala
- ¶Institute of Medical Microbiology, University of Gießen, Schubertstrasse 81, 35392 Gießen, Germany
| | - Trinad Chakraborty
- ¶Institute of Medical Microbiology, University of Gießen, Schubertstrasse 81, 35392 Gießen, Germany
| | - Torsten Hain
- ¶Institute of Medical Microbiology, University of Gießen, Schubertstrasse 81, 35392 Gießen, Germany
| | - Susanne Engelmann
- §Institute of Microbiology, University of Greifswald, F.-L.-Jahn-Strasse 15, 17487 Greifswald, Germany; ‖Institute of Microbiology, Technical University of Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany; **Helmholtz Centre for Infection Research, Microbial Proteomics, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Antje Flieger
- From the ‡Robert Koch Institute, FG11 - Division of Enteropathogenic Bacteria and Legionella, Burgstrasse 37, 38855 Wernigerode, Germany;
| |
Collapse
|
32
|
Laursen MF, Bahl MI, Licht TR, Gram L, Knudsen GM. A single exposure to a sublethal pediocin concentration initiates a resistance-associated temporal cell envelope and general stress response inListeria monocytogenes. Environ Microbiol 2014; 17:1134-51. [DOI: 10.1111/1462-2920.12534] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 06/08/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Martin F. Laursen
- Department of Systems Biology; Technical University of Denmark; DK-2800 Kongens Lyngby Denmark
- National Food Institute; Technical University of Denmark; DK-2860 Søborg Denmark
| | - Martin I. Bahl
- National Food Institute; Technical University of Denmark; DK-2860 Søborg Denmark
| | - Tine R. Licht
- National Food Institute; Technical University of Denmark; DK-2860 Søborg Denmark
| | - Lone Gram
- Department of Systems Biology; Technical University of Denmark; DK-2800 Kongens Lyngby Denmark
| | - Gitte M. Knudsen
- Department of Systems Biology; Technical University of Denmark; DK-2800 Kongens Lyngby Denmark
| |
Collapse
|
33
|
Yu C, Lopez CA, Hu H, Xia Y, Freedman DS, Reddington AP, Daaboul GG, Ünlü MS, Genco CA. A high-throughput method to examine protein-nucleotide interactions identifies targets of the bacterial transcriptional regulatory protein fur. PLoS One 2014; 9:e96832. [PMID: 24811061 PMCID: PMC4014563 DOI: 10.1371/journal.pone.0096832] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/13/2014] [Indexed: 11/19/2022] Open
Abstract
The Ferric uptake regulatory protein (Fur) is a transcriptional regulatory protein that functions to control gene transcription in response to iron in a number of pathogenic bacteria. In this study, we applied a label-free, quantitative and high-throughput analysis method, Interferometric Reflectance Imaging Sensor (IRIS), to rapidly characterize Fur-DNA interactions in vitro with predicted Fur binding sequences in the genome of Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhea. IRIS can easily be applied to examine multiple protein-protein, protein-nucleotide and nucleotide-nucleotide complexes simultaneously and demonstrated here that seventy percent of the predicted Fur boxes in promoter regions of iron-induced genes bound to Fur in vitro with a range of affinities as observed using this microarray screening technology. Combining binding data with mRNA expression levels in a gonococcal fur mutant strain allowed us to identify five new gonococcal genes under Fur-mediated direct regulation.
Collapse
Affiliation(s)
- Chunxiao Yu
- Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, Boston University, Boston, Massachusetts, United States of America
| | - Carlos A. Lopez
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Han Hu
- Bioinformatics Graduate Program, Boston University, Boston, Massachusetts, United States of America
| | - Yu Xia
- Bioinformatics Graduate Program, Boston University, Boston, Massachusetts, United States of America
| | - David S. Freedman
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Alexander P. Reddington
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts, United States of America
| | - George G. Daaboul
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - M. Selim Ünlü
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts, United States of America
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
- Physics Department, Boston University, Boston, Massachusetts, United States of America
| | - Caroline Attardo Genco
- Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, Boston University, Boston, Massachusetts, United States of America
- Department of Microbiology, Boston University School of Medicine, Boston University, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
34
|
The iron stimulon and fur regulon of Geobacter sulfurreducens and their role in energy metabolism. Appl Environ Microbiol 2014; 80:2918-27. [PMID: 24584254 DOI: 10.1128/aem.03916-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Iron plays a critical role in the physiology of Geobacter species. It serves as both an essential component for proteins and cofactors and an electron acceptor during anaerobic respiration. Here, we investigated the iron stimulon and ferric uptake regulator (Fur) regulon of Geobacter sulfurreducens to examine the coordination between uptake of Fe(II) and the reduction of Fe(III) at the transcriptional level. Gene expression studies across a variety of different iron concentrations in both the wild type and a Δfur mutant strain were used to determine the iron stimulon. The stimulon consists of a broad range of gene products, ranging from iron-utilizing to central metabolism and iron reduction proteins. Integration of gene expression and chromatin immunoprecipitation (ChIP) data sets assisted in the identification of the Fur transcriptional regulatory network and Fur's role as a regulator of the iron stimulon. Additional physiological and transcriptional analyses of G. sulfurreducens grown with various Fe(II) concentrations revealed the depth of Fur's involvement in energy metabolism and the existence of redundancy within the iron-regulatory network represented by IdeR, an alternative iron transcriptional regulator. These characteristics enable G. sulfurreducens to thrive in environments with fluctuating iron concentrations by providing it with a robust mechanism to maintain tight and deliberate control over intracellular iron homeostasis.
Collapse
|
35
|
Fillat MF. The FUR (ferric uptake regulator) superfamily: diversity and versatility of key transcriptional regulators. Arch Biochem Biophys 2014; 546:41-52. [PMID: 24513162 DOI: 10.1016/j.abb.2014.01.029] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 01/27/2014] [Accepted: 01/31/2014] [Indexed: 11/17/2022]
Abstract
Control of metal homeostasis is essential for life in all kingdoms. In most prokaryotic organisms the FUR (ferric uptake regulator) family of transcriptional regulators is involved in the regulation of iron and zinc metabolism through control by Fur and Zur proteins. A third member of this family, the peroxide-stress response PerR, is present in most Gram-positives, establishing a tight functional interaction with the global regulator Fur. These proteins play a pivotal role for microbial survival under adverse conditions and in the expression of virulence in most pathogens. In this paper we present the current state of the art in the knowledge of the FUR family, including those members only present in more reduced numbers of bacteria, namely Mur, Nur and Irr. The huge amount of work done in the two last decades shows that FUR proteins present considerable diversity in their regulatory mechanisms and interesting structural differences. However, much work needs to be done to obtain a more complete picture of this family, especially in connection with the roles of some members as gas and redox sensors as well as to fully characterize their participation in bacterial adaptative responses.
Collapse
Affiliation(s)
- María F Fillat
- Department of Biochemistry and Molecular and Cell Biology, Institute for Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, Pedro Cerbuna, 12, 50009 Zaragoza, Spain.
| |
Collapse
|
36
|
Oglesby-Sherrouse AG, Murphy ER. Iron-responsive bacterial small RNAs: variations on a theme. Metallomics 2013; 5:276-86. [PMID: 23340911 DOI: 10.1039/c3mt20224k] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For most living organisms, iron is both essential and potentially toxic, making the precise maintenance of iron homeostasis necessary for survival. To manage this paradox, bacteria regulate the acquisition, utilization, and storage of iron in response to its availability. The iron-dependent ferric uptake repressor (Fur) often mediates this iron-responsive regulation by both direct and indirect mechanisms. In 2002, Masse and Gottesman identified a novel target of Fur-mediated regulation in Escherichia coli: a gene encoding a small regulatory RNA (sRNA) termed RyhB. Under conditions of iron-limitation, RyhB is produced and functions to regulate the expression of several target genes encoding iron-utilizing enzymes, iron acquisition systems, and iron storage factors. This pivotal finding provided the missing link between environmental iron-limitation and previously observed decreases in certain iron-dependent metabolic pathways, a phenomenon now referred to as an "iron-sparing" response. The discovery of RyhB opened the door to the rapidly expanding field of bacterial iron-regulated sRNAs, which continue to be identified and described in numerous bacterial species. Most striking are findings that the impact of iron-responsive sRNA regulation often extends beyond iron homeostasis, particularly with regard to production of virulence-associated factors by pathogenic bacteria. This review discusses trends in the collective body of work on iron-regulated sRNAs, highlighting both the regulatory mechanisms they utilize to control target gene expression and the impact of this regulation on basic processes controlling bacterial physiology and virulence.
Collapse
Affiliation(s)
- Amanda G Oglesby-Sherrouse
- Department of Pharmaceutical Sciences, School of Pharmacy, Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, 20 Penn Street, Baltimore, MD, USA.
| | | |
Collapse
|
37
|
Control of RNA stability by NrrF, an iron-regulated small RNA in Neisseria gonorrhoeae. J Bacteriol 2013; 195:5166-73. [PMID: 24039262 DOI: 10.1128/jb.00839-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Regulation of gene expression by small noncoding RNAs (sRNAs) plays a critical role in bacterial response to physiological stresses. NrrF, a trans-acting sRNA in Neisseria meningitidis and Neisseria gonorrhoeae, has been shown in the meningococcus to control indirectly, in response to iron (Fe) availability, the transcription of genes encoding subunits of succinate dehydrogenase, a Fe-requiring enzyme. Given that in other organisms, sRNAs target multiple mRNAs to control gene expression, we used a global approach to examine the role of NrrF in controlling gonococcal transcription. Three strains, including N. gonorrhoeae FA1090, an nrrF deletion mutant, and a complemented derivative, were examined using a custom CombiMatrix microarray to assess the role of this sRNA in controlling gene expression in response to Fe availability. In the absence of NrrF, the mRNA half-lives for 12 genes under Fe-depleted growth conditions were longer than those in FA1090. The 12 genes controlled by NrrF encoded proteins with biological functions including energy metabolism, oxidative stress, antibiotic resistance, and amino acid synthesis, as well as hypothetical proteins and a regulatory protein whose functions are not fully understood.
Collapse
|
38
|
Cummins J, Casey PG, Joyce SA, Gahan CGM. A mariner transposon-based signature-tagged mutagenesis system for the analysis of oral infection by Listeria monocytogenes. PLoS One 2013; 8:e75437. [PMID: 24069416 PMCID: PMC3771922 DOI: 10.1371/journal.pone.0075437] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 08/14/2013] [Indexed: 11/18/2022] Open
Abstract
Listeria monocytogenes is a Gram-positive foodborne pathogen and the causative agent of listerosis a disease that manifests predominately as meningitis in the non-pregnant individual or infection of the fetus and spontaneous abortion in pregnant women. Common-source outbreaks of foodborne listeriosis are associated with significant morbidity and mortality. However, relatively little is known concerning the mechanisms that govern infection via the oral route. In order to aid functional genetic analysis of the gastrointestinal phase of infection we designed a novel signature-tagged mutagenesis (STM) system based upon the invasive L. monocytogenes 4b serotype H7858 strain. To overcome the limitations of gastrointestinal infection by L. monocytogenes in the mouse model we created a H7858 strain that is genetically optimised for oral infection in mice. Furthermore our STM system was based upon a mariner transposon to favour numerous and random transposition events throughout the L. monocytogenes genome. Use of the STM bank to investigate oral infection by L. monocytogenes identified 21 insertion mutants that demonstrated significantly reduced potential for infection in our model. The sites of transposon insertion included lmOh7858_0671 (encoding an internalin homologous to Lmo0610), lmOh7858_0898 (encoding a putative surface-expressed LPXTG protein homologous to Lmo0842), lmOh7858_2579 (encoding the HupDGC hemin transport system) and lmOh7858_0399 (encoding a putative fructose specific phosphotransferase system). We propose that this represents an optimised STM system for functional genetic analysis of foodborne/oral infection by L. monocytogenes.
Collapse
Affiliation(s)
- Joanne Cummins
- Department of Microbiology, University College Cork, Cork, Ireland
| | - Pat G. Casey
- Department of Microbiology, University College Cork, Cork, Ireland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Susan A. Joyce
- Department of Microbiology, University College Cork, Cork, Ireland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Cormac G. M. Gahan
- Department of Microbiology, University College Cork, Cork, Ireland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
- School of Pharmacy, University College Cork, Cork, Ireland
- * E-mail:
| |
Collapse
|
39
|
Loutet SA, Kobylarz MJ, Chau CHT, Murphy MEP. IruO is a reductase for heme degradation by IsdI and IsdG proteins in Staphylococcus aureus. J Biol Chem 2013; 288:25749-25759. [PMID: 23893407 DOI: 10.1074/jbc.m113.470518] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus aureus is a common hospital- and community-acquired bacterium that can cause devastating infections and is often multidrug-resistant. Iron acquisition is required by S. aureus during an infection, and iron acquisition pathways are potential targets for therapies. The gene NWMN2274 in S. aureus strain Newman is annotated as an oxidoreductase of the diverse pyridine nucleotide-disulfide oxidoreductase (PNDO) family. We show that NWMN2274 is an electron donor to IsdG and IsdI catalyzing the degradation of heme, and we have renamed this protein IruO. Recombinant IruO is a FAD-containing NADPH-dependent reductase. In the presence of NADPH and IruO, either IsdI or IsdG degraded bound heme 10-fold more rapidly than with the chemical reductant ascorbic acid. Varying IsdI-heme substrate and monitoring loss of the heme Soret band gave a K(m) of 15 ± 4 μM, a k(cat) of 5.2 ± 0.7 min(-1), and a k(cat)/K(m) of 5.8 × 10(3) M(-1) s(-1). From HPLC and electronic spectra, the major heme degradation products are 5-oxo-δ-bilirubin and 15-oxo-β-bilirubin (staphylobilins), as observed with ascorbic acid. Although heme degradation by IsdI or IsdG can occur in the presence of H2O2, the addition of catalase and superoxide dismutase did not disrupt NADPH/IruO heme degradation reactions. The degree of electron coupling between IruO and IsdI or IsdG remains to be determined. Homologs of IruO were identified by sequence similarity in the genomes of Gram-positive bacteria that possess IsdG-family heme oxygenases. A phylogeny of these homologs identifies a distinct clade of pyridine nucleotide-disulfide oxidoreductases likely involved in iron uptake systems. IruO is the likely in vivo reductant required for heme degradation by S. aureus.
Collapse
Affiliation(s)
- Slade A Loutet
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Marek J Kobylarz
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Crystal H T Chau
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael E P Murphy
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
| |
Collapse
|
40
|
Machado H, Lourenço A, Carvalho F, Cabanes D, Kallipolitis BH, Brito L. The Tat pathway is prevalent in Listeria monocytogenes lineage II and is not required for infection and spread in host cells. J Mol Microbiol Biotechnol 2013; 23:209-18. [PMID: 23595063 DOI: 10.1159/000348245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Listeria monocytogenes, a foodborne pathogenic bacterium, remains a serious public health concern due to its frequent occurrence in food products coupled with a high mortality rate. Bacterial pathogenicity depends greatly on the ability to secrete virulence factors to or beyond the bacterial cell surface. The Tat pathway, one of the secretion systems present in L. monocytogenes, was until now only investigated in silico. In L. monocytogenes strain EGDe two genes constitute this pathway, tatC(lmo0361) and tatA(lmo0362). Here we show that tatC and tatA are cotranscribed in a bicistronic- and growth-phase-dependent manner, being downregulated in the stationary phase. An EGDe tatAC mutant strain (EGDe ΔtatAC) was constructed, confirming that the Tat pathway is not essential for L.monocytogenes survival or biofilm-forming ability. When compared to the wild-type EGDe, deletion of tatAC did not decrease the virulence potential of EGDe ΔtatAC in HT-29 human epithelial cell line and even increased (p < 0.05) the virulence potential for mice. Moreover, we show that tat genes are prevalent in L. monocytogenes strains belonging to genetic lineage II and are generally absent from lineage I, which is more associated with human cases, thus excluding the possibility of using the Tat system as a target for novel antimicrobial compounds targeting L.monocytogenes.
Collapse
Affiliation(s)
- Henrique Machado
- CBAA/DRAT, Laboratório de Microbiologia, Instituto Superior de Agronomia, Technical University of Lisbon, Lisbon, Portugal
| | | | | | | | | | | |
Collapse
|
41
|
Wang J, Wu G, Chen L, Zhang W. Cross-species transcriptional network analysis reveals conservation and variation in response to metal stress in cyanobacteria. BMC Genomics 2013; 14:112. [PMID: 23421563 PMCID: PMC3598940 DOI: 10.1186/1471-2164-14-112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 02/13/2013] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND As one of the most dominant bacterial groups on Earth, cyanobacteria play a pivotal role in the global carbon cycling and the Earth atmosphere composition. Understanding their molecular responses to environmental perturbations has important scientific and environmental values. Since important biological processes or networks are often evolutionarily conserved, the cross-species transcriptional network analysis offers a useful strategy to decipher conserved and species-specific transcriptional mechanisms that cells utilize to deal with various biotic and abiotic disturbances, and it will eventually lead to a better understanding of associated adaptation and regulatory networks. RESULTS In this study, the Weighted Gene Co-expression Network Analysis (WGCNA) approach was used to establish transcriptional networks for four important cyanobacteria species under metal stress, including iron depletion and high copper conditions. Cross-species network comparison led to discovery of several core response modules and genes possibly essential to metal stress, as well as species-specific hub genes for metal stresses in different cyanobacteria species, shedding light on survival strategies of cyanobacteria responding to different environmental perturbations. CONCLUSIONS The WGCNA analysis demonstrated that the application of cross-species transcriptional network analysis will lead to novel insights to molecular response to environmental changes which will otherwise not be achieved by analyzing data from a single species.
Collapse
Affiliation(s)
- Jiangxin Wang
- School of Chemical Engineering & Technology, Tianjin University, 300072, Tianjin, People's Republic of China
| | | | | | | |
Collapse
|
42
|
Andrews S, Norton I, Salunkhe AS, Goodluck H, Aly WSM, Mourad-Agha H, Cornelis P. Control of iron metabolism in bacteria. Met Ions Life Sci 2013; 12:203-39. [PMID: 23595674 DOI: 10.1007/978-94-007-5561-1_7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Bacteria depend upon iron as a vital cofactor that enables a wide range of key metabolic activities. Bacteria must therefore ensure a balanced supply of this essential metal. To do so, they invest considerable resourse into its acquisition and employ elaborate control mechanisms to eleviate both iron-induced toxitiy as well as iron deficiency. This chapter describes the processes that bacteria engage in maintaining iron homeostasis. The focus is Escherichia coli, as this bacterium provides a well studied example. A summary of the current status of understanding of iron management at the 'omics' level is also presented.
Collapse
Affiliation(s)
- Simon Andrews
- The School of Biological Sciences, The University of Reading, Whiteknights, Reading, RG6 6AJ, UK,
| | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
The ferric uptake regulator (Fur) protein has been shown to function as a repressor of transcription in a number of diverse microorganisms. However, recent studies have established that Fur can function at a global level as both an activator and a repressor of transcription through both direct and indirect mechanisms. Fur-mediated indirect activation occurs via the repression of additional repressor proteins, or small regulatory RNAs, thereby activating transcription of a previously silent gene. Fur mediates direct activation through binding of Fur to the promoter regions of genes. Whereas the repressive mechanism of Fur has been thoroughly investigated, emerging studies on direct and indirect Fur-mediated activation mechanisms have revealed novel global regulatory circuits.
Collapse
|
44
|
Structure and regulon of Campylobacter jejuni ferric uptake regulator Fur define apo-Fur regulation. Proc Natl Acad Sci U S A 2012; 109:10047-52. [PMID: 22665794 DOI: 10.1073/pnas.1118321109] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The full regulatory potential of the ferric uptake regulator (Fur) family of proteins remains undefined despite over 20 years of study. We report herein an integrated approach that combines both genome-wide technologies and structural studies to define the role of Fur in Campylobacter jejuni (Cj). CjFur ChIP-chip assays identified 95 genomic loci bound by CjFur associated with functions as diverse as iron acquisition, flagellar biogenesis, and non-iron ion transport. Comparative analysis with transcriptomic data revealed that CjFur regulation extends beyond solely repression and also includes both gene activation and iron-independent regulation. Computational analysis revealed the presence of an elongated holo-Fur repression motif along with a divergent holo-Fur activation motif. This diversity of CjFur DNA-binding elements is supported by the crystal structure of CjFur, which revealed a unique conformation of its DNA-binding domain and the absence of metal in the regulatory site. Strikingly, our results indicate that the apo-CjFur structure retains the canonical V-shaped dimer reminiscent of previously characterized holo-Fur proteins enabling DNA interaction. This conformation stems from a structurally unique hinge domain that is poised to further contribute to CjFur's regulatory functions by modulating the orientation of the DNA-binding domain upon binding of iron. The unique features of the CjFur crystal structure rationalize the binding sequence diversity that was uncovered during ChIP-chip analysis and defines apo-Fur regulation.
Collapse
|
45
|
Bowman JP, Hages E, Nilsson RE, Kocharunchitt C, Ross T. Investigation of the Listeria monocytogenes Scott A acid tolerance response and associated physiological and phenotypic features via whole proteome analysis. J Proteome Res 2012; 11:2409-26. [PMID: 22372944 DOI: 10.1021/pr201137c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The global proteomic responses of the foodborne pathogen Listeria monocytogenes strain Scott A, during active growth and transition to the stationary growth phase under progressively more acidic conditions, created by addition of lactic acid and HCl, were investigated using label-free liquid chromatography/tandem mass spectrometry. Approximately 56% of the Scott A proteome was quantitatively assessable, and the data provides insight into its acquired acid tolerance response (ATR) as well as the relation of the ATR to the growth phase transition. Alterations in protein abundance due to acid stress were focused in proteins belonging to the L. monocytogenes common genome, with few strain-dependent proteins involved. However, one of the two complete prophage genomes appeared to enter lysogeny. During progressive acidification, the growth rate and yield were reduced 55% and 98%, respectively, in comparison to nonacidified control cultures. The maintenance of the growth rate was determined to be connected to activation of cytoplasmic pH homeostatic mechanisms while cellular reproductive-related and cell component turnover proteins were markedly more abundant in acid stressed cultures. Cell biomass accumulation was impeded predominantly due to repression of phosphodonor-linked enzymes involved with sugar phosphotransfer, glycolysis, and cell wall polymer biosynthesis. Acidification caused a shift from heterofermentation to an oxidatively stressed state in which ATP appears to be generated mainly through the pyruvate dehydrogenase/pyruvate oxidase/phosphotransacetylase/acetate kinase and branched chain acid dehydrogenase pathways. Analysis of regulons indicated energy conservation occurs due to repression by the GTP/isoleucine sensor CodY and also the RelA mediated stringent response. Whole proteome analysis proved to be an effective way to highlight proteins involved with the acquisition of the ATR.
Collapse
Affiliation(s)
- John P Bowman
- Food Safety Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia.
| | | | | | | | | |
Collapse
|
46
|
McLaughlin HP, Xiao Q, Rea RB, Pi H, Casey PG, Darby T, Charbit A, Sleator RD, Joyce SA, Cowart RE, Hill C, Klebba PE, Gahan CGM. A putative P-type ATPase required for virulence and resistance to haem toxicity in Listeria monocytogenes. PLoS One 2012; 7:e30928. [PMID: 22363518 PMCID: PMC3283593 DOI: 10.1371/journal.pone.0030928] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 12/26/2011] [Indexed: 11/18/2022] Open
Abstract
Regulation of iron homeostasis in many pathogens is principally mediated by the ferric uptake regulator, Fur. Since acquisition of iron from the host is essential for the intracellular pathogen Listeria monocytogenes, we predicted the existence of Fur-regulated systems that support infection. We examined the contribution of nine Fur-regulated loci to the pathogenicity of L. monocytogenes in a murine model of infection. While mutating the majority of the genes failed to affect virulence, three mutants exhibited a significantly compromised virulence potential. Most striking was the role of the membrane protein we designate FrvA (Fur regulated virulence factor A; encoded by frvA [lmo0641]), which is absolutely required for the systemic phase of infection in mice and also for virulence in an alternative infection model, the Wax Moth Galleria mellonella. Further analysis of the ΔfrvA mutant revealed poor growth in iron deficient media and inhibition of growth by micromolar concentrations of haem or haemoglobin, a phenotype which may contribute to the attenuated growth of this mutant during infection. Uptake studies indicated that the ΔfrvA mutant is unaffected in the uptake of ferric citrate but demonstrates a significant increase in uptake of haem and haemin. The data suggest a potential role for FrvA as a haem exporter that functions, at least in part, to protect the cell against the potential toxicity of free haem.
Collapse
Affiliation(s)
- Heather P. McLaughlin
- Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland
| | - Qiaobin Xiao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Rosemarie B. Rea
- Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland
- Department of Biological Sciences, Cork Institute of Technology, Cork, Ireland
| | - Hualiang Pi
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Pat G. Casey
- Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland
| | - Trevor Darby
- Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland
| | - Alain Charbit
- Université Paris Descartes, Faculté de Médecine Necker-Enfants Malades, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
| | - Roy D. Sleator
- Department of Biological Sciences, Cork Institute of Technology, Cork, Ireland
| | - Susan A. Joyce
- Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland
| | - Richard E. Cowart
- Division of Biological Science, Department of Natural and Applied Sciences, University of Dubuque, Dubuque, Iowa, United States of America
| | - Colin Hill
- Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland
- * E-mail:
| | - Phillip E. Klebba
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Cormac G. M. Gahan
- Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland
- School of Pharmacy, University College Cork, Cork, Ireland
| |
Collapse
|
47
|
Metalloregulation of Gram-positive pathogen physiology. Curr Opin Microbiol 2011; 15:169-74. [PMID: 22155062 DOI: 10.1016/j.mib.2011.11.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Accepted: 11/17/2011] [Indexed: 01/09/2023]
Abstract
Owing to the unique redox potential of transition metals, many of these elements serve important roles as cofactors in numerous enzymes. However, the reactive nature of metal becomes an intracellular threat when these ions are present in excess. Therefore, all organisms require mechanisms for sensing small fluctuations in metal levels to maintain a controlled balance of uptake, efflux, and sequestration. The ability to sense metal ion concentration is especially important for the survival of pathogenic bacteria because host organisms can both restrict access to essential metals from invading pathogens and utilize the innate toxicity of certain metals for bacterial killing. Host-induced metal ion fluctuations must be rapidly sensed by pathogenic bacteria so that they can activate metal transport systems, alter their physiology to accommodate differences in metal concentrations, and regulate the expression of virulence factors.
Collapse
|
48
|
Illuminating the landscape of host-pathogen interactions with the bacterium Listeria monocytogenes. Proc Natl Acad Sci U S A 2011; 108:19484-91. [PMID: 22114192 DOI: 10.1073/pnas.1112371108] [Citation(s) in RCA: 253] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Listeria monocytogenes has, in 25 y, become a model in infection biology. Through the analysis of both its saprophytic life and infectious process, new concepts in microbiology, cell biology, and pathogenesis have been discovered. This review will update our knowledge on this intracellular pathogen and highlight the most recent breakthroughs. Promising areas of investigation such as the increasingly recognized relevance for the infectious process, of RNA-mediated regulations in the bacterium, and the role of bacterially controlled posttranslational and epigenetic modifications in the host will also be discussed.
Collapse
|
49
|
Piveteau P, Depret G, Pivato B, Garmyn D, Hartmann A. Changes in gene expression during adaptation of Listeria monocytogenes to the soil environment. PLoS One 2011; 6:e24881. [PMID: 21966375 PMCID: PMC3179493 DOI: 10.1371/journal.pone.0024881] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 08/19/2011] [Indexed: 12/31/2022] Open
Abstract
Listeria monocytogenes is a ubiquitous opportunistic pathogen responsible for listeriosis. In order to study the processes underlying its ability to adapt to the soil environment, whole-genome arrays were used to analyse transcriptome modifications 15 minutes, 30 minutes and 18 h after inoculation of L. monocytogenes EGD-e in soil extracts. Growth was observed within the first day of incubation and large numbers were still detected in soil extract and soil microcosms one year after the start of the experiment. Major transcriptional reprofiling was observed. Nutrient acquisition mechanisms (phosphoenolpyruvate-dependent phosphotransferase systems and ABC transporters) and enzymes involved in catabolism of specific carbohydrates (β-glucosidases; chitinases) were prevalent. This is consistent with the overrepresentation of the CodY regulon that suggests that in a nutrient depleted environment, L. monocytogenes recruits its extensive repertoire of transporters to acquire a range of substrates for energy production.
Collapse
|
50
|
Mapping the regulon of Vibrio cholerae ferric uptake regulator expands its known network of gene regulation. Proc Natl Acad Sci U S A 2011; 108:12467-72. [PMID: 21750152 DOI: 10.1073/pnas.1107894108] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
ChIP coupled with next-generation sequencing (ChIP-seq) has revolutionized whole-genome mapping of DNA-binding protein sites. Although ChIP-seq rapidly gained support in eukaryotic systems, it remains underused in the mapping of bacterial transcriptional regulator-binding sites. Using the virulence-required iron-responsive ferric uptake regulator (Fur), we report a simple, broadly applicable ChIP-seq method in the pathogen Vibrio cholerae. Combining our ChIP-seq results with available microarray data, we clarify direct and indirect Fur regulation of known iron-responsive genes. We validate a subset of Fur-binding sites in vivo and show a common motif present in all Fur ChIP-seq peaks that has enhanced binding affinity for purified V. cholerae Fur. Further analysis shows that V. cholerae Fur directly regulates several additional genes associated with Fur-binding sites, expanding the role of this transcription factor into the regulation of ribosome formation, additional transport functions, and unique sRNAs.
Collapse
|