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Sultana T, Morgan DM, Jernberg BD, Zak P, Sinha SC, Colbert CL. Biophysical and Solution Structure Analysis of Critical Residues Involved in the Interaction between the PupB N-Terminal Signaling Domain and PupR C-Terminal Cell Surface Signaling Domain from Pseudomonas capeferrum. Biomolecules 2024; 14:1108. [PMID: 39334875 PMCID: PMC11429574 DOI: 10.3390/biom14091108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 08/21/2024] [Accepted: 08/23/2024] [Indexed: 09/30/2024] Open
Abstract
Cell surface signaling (CSS) is a means of rapidly adjusting transcription in response to extracellular stimuli in Gram-negative bacteria. The pseudobactin BN7/8 uptake (Pup) system not only imports iron but also upregulates its own transcription through CSS in Pseudomonas capeferrum. In the absence of ferric pseudobactin BN7/8, the signaling components are maintained in a resting state via the formation of a periplasmic complex between the N-terminal signaling domain (NTSD) of the outer membrane iron-transporter, PupB, and the C-terminal CSS domain (CCSSD) of the sigma regulator, PupR. The previously determined 1.6 Å crystal structure of this periplasmic complex has allowed us to probe the structural and thermodynamic consequences of mutating key interfacial residues. In this report, we describe the solution structure of the PupB NTSD and use Nuclear Magnetic Resonance spectroscopy, Isothermal Titration Calorimetry, and Circular Dichroism spectroscopy together with thermal denaturation to investigate whether three PupB point mutations, Q69K, H72D, and L74A, influence the interaction merely due to the chemical nature of the amino acid substitution or also cause changes in overall protein structure. Our results demonstrate that binding to the PupR CCSSD does not alter the structure of PupB NTSD and that the individual mutations have only minor effects on structure. The mutations generally lower thermodynamic stability of the NTSD and weaken binding to the CCSSD. These findings validate the X-ray crystal structure interface, emphasizing the importance of amino acid chemical nature at the interface.
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Affiliation(s)
- Tajnin Sultana
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108, USA
| | - David M Morgan
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108, USA
- Independent Researcher, Winnipeg, MB R3C 0Z5, Canada
| | - Beau D Jernberg
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108, USA
- Bio-Techne Corporation, 614 McKinley Place NE, Minneapolis, MN 55413, USA
| | - Peyton Zak
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108, USA
| | - Sangita C Sinha
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108, USA
| | - Christopher L Colbert
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108, USA
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Will V, Frey C, Normant V, Kuhn L, Chicher J, Volck F, Schalk IJ. The role of FoxA, FiuA, and FpvB in iron acquisition via hydroxamate-type siderophores in Pseudomonas aeruginosa. Sci Rep 2024; 14:18795. [PMID: 39138320 PMCID: PMC11322547 DOI: 10.1038/s41598-024-69152-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Accepted: 08/01/2024] [Indexed: 08/15/2024] Open
Abstract
Siderophores are specialized molecules produced by bacteria and fungi to scavenge iron, a crucial nutrient for growth and metabolism. Catecholate-type siderophores are mainly produced by bacteria, while hydroxamates are mostly from fungi. This study investigates the capacity of nine hydroxamate-type siderophores from fungi and Streptomyces to facilitate iron acquisition by the human pathogen Pseudomonas aeruginosa. Growth assays under iron limitation and 55Fe incorporation tests showed that all nine siderophores promoted bacterial growth and iron transport. The study also aimed to identify the TonB-dependent transporters (TBDTs) involved in iron import by these siderophores. Using mutant strains lacking specific TBDT genes, it was found that iron is imported into P. aeruginosa cells by FpvB for coprogen, triacetylfusarinine, fusigen, ferrirhodin, and ferrirubin. Iron complexed by desferioxamine G is transported by FpvB and FoxA, ferricrocin-Fe and ferrichrycin-Fe by FpvB and FiuA, and rhodotoluric acid-Fe by FpvB, FiuA, and another unidentified TBDT. These findings highlight the effectiveness of hydroxamate-type siderophores in iron transport into P. aeruginosa and provide insights into the complex molecular mechanisms involved, which are important for understanding microbial interactions and ecological balance.
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Affiliation(s)
- Virginie Will
- CNRS, UMR7242, UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
- UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
| | - Chloé Frey
- CNRS, UMR7242, UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
- UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
| | - Vincent Normant
- CNRS, UMR7242, UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
- UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
| | - Lauriane Kuhn
- Institut de Biologie Moléculaire Et Cellulaire, CNRS, UAR1589, Plateforme Proteomique Strasbourg - Esplanade, 2 Allée Konrad Roentgen, 67084, Strasbourg Cedex, France
| | - Johana Chicher
- Institut de Biologie Moléculaire Et Cellulaire, CNRS, UAR1589, Plateforme Proteomique Strasbourg - Esplanade, 2 Allée Konrad Roentgen, 67084, Strasbourg Cedex, France
| | - Florian Volck
- CNRS, UMR7242, UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
- UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
| | - Isabelle J Schalk
- CNRS, UMR7242, UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France.
- UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France.
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Zytnick AM, Gutenthaler-Tietze SM, Aron AT, Reitz ZL, Phi MT, Good NM, Petras D, Daumann LJ, Martinez-Gomez NC. Identification and characterization of a small-molecule metallophore involved in lanthanide metabolism. Proc Natl Acad Sci U S A 2024; 121:e2322096121. [PMID: 39078674 PMCID: PMC11317620 DOI: 10.1073/pnas.2322096121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 06/14/2024] [Indexed: 07/31/2024] Open
Abstract
Many bacteria secrete metallophores, low-molecular-weight organic compounds that bind ions with high selectivity and affinity, in order to access essential metals from the environment. Previous work has elucidated the structures and biosynthetic machinery of metallophores specific for iron, zinc, nickel, molybdenum, and copper. No physiologically relevant lanthanide-binding metallophore has been discovered despite the knowledge that lanthanide metals (Ln) have been revealed to be essential cofactors for certain alcohol dehydrogenases across a diverse range of phyla. Here, we report the biosynthetic machinery, the structure, and the physiological relevance of a lanthanophore, methylolanthanin. The structure of methylolanthanin exhibits a unique 4-hydroxybenzoate moiety which has not previously been described in other metallophores. We find that production of methylolanthanin is required for normal levels of Ln accumulation in the methylotrophic bacterium Methylobacterium extorquens AM1, while overexpression of the molecule greatly increases bioaccumulation and adsorption. Our results provide a clearer understanding of how Ln-utilizing bacteria sense, scavenge, and store Ln; essential processes in the environment where Ln are poorly bioavailable. More broadly, the identification of this lanthanophore opens doors for study of how biosynthetic gene clusters are repurposed for additional functions and the complex relationship between metal homeostasis and fitness.
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Affiliation(s)
- Alexa M. Zytnick
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA94720
| | - Sophie M. Gutenthaler-Tietze
- Department of Chemistry, Ludwig-Maximilians-Universität München, Munich 81377, Germany
- Chair of Bioinorganic Chemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf40225, Germany
| | - Allegra T. Aron
- Department of Chemistry and Biochemistry, University of Denver, Denver, CO80210
| | - Zachary L. Reitz
- Bioinformatics Group, Wageningen University, Wageningen6708PB, The Netherlands
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA93117
| | - Manh Tri Phi
- Department of Chemistry, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Nathan M. Good
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA94720
| | - Daniel Petras
- Interfaculty Institute of Microbiology and Medicine, Universität Tübingen, Tübingen72074, Germany
| | - Lena J. Daumann
- Department of Chemistry, Ludwig-Maximilians-Universität München, Munich 81377, Germany
- Chair of Bioinorganic Chemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf40225, Germany
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Reitz ZL. Predicting metallophore structure and function through genome mining. Methods Enzymol 2024; 702:371-401. [PMID: 39155119 DOI: 10.1016/bs.mie.2024.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
Metallophores are small molecule chelators that many microbes use to obtain trace metals from their environment. Through genome mining, where genomes are scanned for metallophore biosynthesis genes, one can not only identify which organisms are likely to produce a metallophore, but also predict the metallophore structure, thus preventing undesired reisolation of known compounds and accelerating characterization. Furthermore, the presence of accessory genes for the transport, utilization, and regulation can suggest the biological function and fate of a metallophore. Modern, user-friendly tools have made powerful genomic analyses accessible to scientists with no bioinformatics experience, but these tools are often not utilized to their full potential. This chapter provides an introduction to metallophore genomics and demonstrates how to use the free, publicly available antiSMASH platform to infer metallophore function and structure.
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Affiliation(s)
- Zachary L Reitz
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, United States.
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de Assis Noman G, Lacerda de Moura BE, Vieira ML. Leptospiral LipL45 lipoprotein undergoes processing and shares structural similarities with bacterial sigma regulators. Biochem Biophys Res Commun 2024; 717:150057. [PMID: 38718568 DOI: 10.1016/j.bbrc.2024.150057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/23/2024] [Accepted: 05/03/2024] [Indexed: 05/21/2024]
Abstract
Leptospirosis is a widespread zoonotic infectious disease of human and veterinary concern caused by pathogenic spirochetes of the genus Leptospira. To date, little progress towards understanding leptospiral pathogenesis and identification of virulence factors has been made, which is the main bottleneck for developing effective measures against the disease. Some leptospiral proteins, including LipL32, Lig proteins, LipL45, and LipL21, are being considered as potential virulence factors or vaccine candidates. However, their function remains to be established. LipL45 is the most expressed membrane lipoprotein in leptospires, upregulated when the bacteria are transferred to temperatures resembling the host, expressed during infection, suppressed after culture attenuation, and known to suffer processing in vivo and in vitro, generating fragments. Based on body of evidence, we hypothesized that the LipL45 processing might occur by an auto-cleavage event, deriving two fragments. The results presented here, based on bioinformatics, structure modeling analysis, and experimental data, corroborate that LipL45 processing probably includes a self-catalyzed non-proteolytic event and suggest the participation of LipL45 in cell-surface signaling pathways, as the protein shares structural similarities with bacterial sigma regulators. Our data indicate that LipL45 might play an important role in response to environmental conditions, with possible function in the adaptation to the host.
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Affiliation(s)
- Gabriel de Assis Noman
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil; Programa de Pós-graduação Em Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil.
| | | | - Mônica Larucci Vieira
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil; Programa de Pós-graduação Em Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil.
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Wang X, Kang H, Huang K, Guo M, Wu Y, Ying T, Liu Y, Wei D. Antibody Nanotweezer Constructing Bivalent Transistor-Biomolecule Interface with Spatial Tolerance. NANO LETTERS 2024; 24:3914-3921. [PMID: 38513214 DOI: 10.1021/acs.nanolett.3c05140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Establishing a multivalent interface between the biointerface of a living system and electronic device is vital to building intelligent bioelectronic systems. How to achieve multivalent binding with spatial tolerance at the nanoscale remains challenging. Here, we report an antibody nanotweezer that is a self-adaptive bivalent nanobody enabling strong and resilient binding between transistor and envelope proteins at biointerfaces. The antibody nanotweezer is constructed by a DNA framework, where the nanoscale patterning of nanobodies along with their local spatial adaptivity enables simultaneous recognition of target epitopes without binding stress. As such, effective binding affinity increases by 1 order of magnitude compared with monovalent antibody. The antibody nanotweezer operating on transistor offers enhanced signal transduction, which is implemented to detect clinical pathogens, showing ∼100% overall agreement with PCR results. This work provides a perspective of engineering multivalent interfaces between biosystems with solid-state devices, holding great potential for organoid intelligence on a chip.
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Affiliation(s)
- Xuejun Wang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Department of Material Science, Fudan University, Shanghai 200433, China
| | - Hua Kang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Department of Material Science, Fudan University, Shanghai 200433, China
| | - Keke Huang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Mingquan Guo
- Shanghai Institute of Phage, Department of Laboratory Medicine, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Yanling Wu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Tianlei Ying
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yunqi Liu
- Laboratory of Molecular Materials and Devices, Department of Material Science, Fudan University, Shanghai 200433, China
| | - Dacheng Wei
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Department of Material Science, Fudan University, Shanghai 200433, China
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Chu XJ, Song DD, Zhou MH, Chen XZ, Chu N, Li M, Li BZ, Liu SH, Hou S, Wu JB, Gong L. Perturbations in gut and respiratory microbiota in COVID-19 and influenza patients: a systematic review and meta-analysis. Front Med (Lausanne) 2024; 11:1301312. [PMID: 38405190 PMCID: PMC10884097 DOI: 10.3389/fmed.2024.1301312] [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: 09/27/2023] [Accepted: 01/17/2024] [Indexed: 02/27/2024] Open
Abstract
Objectives Coronavirus disease-19 (COVID-19)/influenza poses unprecedented challenges to the global economy and healthcare services. Numerous studies have described alterations in the microbiome of COVID-19/influenza patients, but further investigation is needed to understand the relationship between the microbiome and these diseases. Herein, through systematic comparison between COVID-19 patients, long COVID-19 patients, influenza patients, no COVID-19/influenza controls and no COVID-19/influenza patients, we conducted a comprehensive review to describe the microbial change of respiratory tract/digestive tract in COVID-19/influenza patients. Methods We systematically reviewed relevant literature by searching the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2023. We conducted a comprehensive review to explore microbial alterations in patients with COVID-19/influenza. In addition, the data on α-diversity were summarized and analyzed by meta-analysis. Results A total of 134 studies comparing COVID-19 patients with controls and 18 studies comparing influenza patients with controls were included. The Shannon indices of the gut and respiratory tract microbiome were slightly decreased in COVID-19/influenza patients compared to no COVID-19/influenza controls. Meanwhile, COVID-19 patients with more severe symptoms also exhibited a lower Shannon index versus COVID-19 patients with milder symptoms. The intestinal microbiome of COVID-19 patients was characterized by elevated opportunistic pathogens along with reduced short-chain fatty acid (SCFAs)-producing microbiota. Moreover, Enterobacteriaceae (including Escherichia and Enterococcus) and Lactococcus, were enriched in the gut and respiratory tract of COVID-19 patients. Conversely, Haemophilus and Neisseria showed reduced abundance in the respiratory tract of both COVID-19 and influenza patients. Conclusion In this systematic review, we identified the microbiome in COVID-19/influenza patients in comparison with controls. The microbial changes in influenza and COVID-19 are partly similar.
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Affiliation(s)
- Xiu-Jie Chu
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
| | - Dan-Dan Song
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
| | - Ming-Hua Zhou
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Xiu-Zhi Chen
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
| | - Na Chu
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
| | - Ming Li
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
| | - Bao-Zhu Li
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Song-Hui Liu
- School of Public Health, Bengbu Medical College, Bengbu, Anhui, China
| | - Sai Hou
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
| | - Jia-Bing Wu
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
| | - Lei Gong
- Department of Acute Infectious Disease Prevention and Control, Anhui Provincial Center for Disease Control and Prevention, Hefei, Anhui, China
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Ma X, Wang W, Cai L, Xiao M, He F, Liu Z, Chen D, Wang Y, Shen L, Gu Y. Analysis of the microbial diversity in takin ( Budorcas taxicolor) feces. Front Microbiol 2023; 14:1303085. [PMID: 38188576 PMCID: PMC10768053 DOI: 10.3389/fmicb.2023.1303085] [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: 09/27/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024] Open
Abstract
Introduction The intestinal tract of animals is a complex and dynamic microecosystem that is inextricably linked to the health of the host organism. Takin (Budorcas taxicolor) is a threatened species, and its gut microbiome is poorly understood. Therefore, this study aimed to analyze the microbial community structure and potential pathogens of takin. Methods Takin fecal samples were collected from five sites in a nature reserve to ensure the uniformity of sample collection, determine the effects of different geographical locations on gut microbes, and analyze the differences in microbial communities between sites. Subsequently, high-throughput 16S rDNA gene sequencing was performed to analyze the microbial diversity and potential pathogens in the gut; the findings were verified by isolating and culturing bacteria and metagenomic sequencing. Results and discussion The takin gut microflora consisted mainly of four phyla: Firmicutes (69.72%), Bacteroidota (13.55%), Proteobacteria (9.02%), and Verrucomicrobiota (3.77%), representing 96.07% of all microorganisms. The main genera were UCG-005 (20.25%), UCG-010_unclassified (12.35%), Firmicus_unclassified (4.03%), and Rumino coccsea_unclassified (3.49%), while the main species were assigned to Bacteria_unclassified. Potential pathogens were also detected, which could be used as a reference for the protection of takin. Pseudomonas presented the highest abundance at Shuichiping and may represent the main pathogen responsible for the death of takin at the site. This study provides an important reference for investigating the composition of the bacterial community in the intestine of takin.
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Affiliation(s)
- Xiaoping Ma
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Weichen Wang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Lijun Cai
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Management Office of Tangjiahe National Nature Reserve, Qingchuan, China
| | - Mei Xiao
- Management Office of Tangjiahe National Nature Reserve, Qingchuan, China
| | - Fang He
- Management Office of Tangjiahe National Nature Reserve, Qingchuan, China
| | - Zhen Liu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dong Chen
- Sichuan Provincial Center for Animal Disease Prevention and Control, Chengdu, China
| | - Ya Wang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Limin Shen
- Management Office of Tangjiahe National Nature Reserve, Qingchuan, China
| | - Yu Gu
- College of Life Sciences, Sichuan Agricultural University, Chengdu, China
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Zhao C, Duan X, Liu C, Huang H, Wu M, Zhang X, Chen Y. Metabolite Cross-Feeding Promoting NADH Production and Electron Transfer during Efficient SMX Biodegradation by a Denitrifier and S. oneidensis MR-1 in the Presence of Nitrate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18306-18316. [PMID: 37043541 DOI: 10.1021/acs.est.2c09341] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Antibiotics often coexist with other pollutants (e.g., nitrate) in an aquatic environment, and their simultaneous biological removal has attracted widespread interest. We have found that sulfamethoxazole (SMX) and nitrate can be efficiently removed by the coculture of a model denitrifier (Paracoccus denitrificans, Pd) and Shewanella oneidensis MR-1 (So), and SMX degradation is affected by NADH production and electron transfer. In this paper, the mechanism of a coculture promoting NADH production and electron transfer was investigated by proteomic analysis and intermediate experiments. The results showed that glutamine and lactate produced by Pd were captured by So to synthesize thiamine and heme, and the released thiamine was taken up by Pd as a cofactor of pyruvate and ketoglutarate dehydrogenase, which were related to NADH generation. Additionally, Pd acquired heme, which facilitated electron transfer as heme, was the important composition of complex III and cytochrome c and the iron source of iron sulfur clusters, the key component of complex I in the electron transfer chain. Further investigation revealed that lactate and glutamine generated by Pd prompted So chemotactic moving toward Pd, which helped the two bacteria effectively obtain their required substances. Obviously, metabolite cross-feeding promoted NADH production and electron transfer, resulting in efficient SMX biodegradation by Pd and So in the presence of nitrate. Its feasibility was finally verified by the coculture of an activated sludge denitrifier and So.
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Affiliation(s)
- Chunxia Zhao
- State Key Laboratory of Pollution Control and ReSource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xu Duan
- State Key Laboratory of Pollution Control and ReSource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Chao Liu
- State Key Laboratory of Pollution Control and ReSource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Haining Huang
- State Key Laboratory of Pollution Control and ReSource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Meirou Wu
- State Key Laboratory of Pollution Control and ReSource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xuemeng Zhang
- State Key Laboratory of Pollution Control and ReSource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and ReSource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
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10
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Hubert T, Madec M, Schalk IJ. Experimental and computational methods to highlight behavioural variations in TonB-dependent transporter expression in Pseudomonas aeruginosa versus siderophore concentration. Sci Rep 2023; 13:20015. [PMID: 37974013 PMCID: PMC10654771 DOI: 10.1038/s41598-023-46585-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023] Open
Abstract
Iron is a key nutrient for bacterial growth. The source can be either heme or siderophore-Fe complexes. Siderophores are small molecules synthesized by bacteria to scavenge iron from the bacterial environment. The pathogen Pseudomonas aeruginosa can express at least 15 different iron uptake pathways and all but one involve a TonB-dependent transporter (TBDT) for the uptake of iron across the outer membrane. Little is known about how bacteria modulate and adapt the expression of their different iron import pathways according to their environment. Here, we have developed fluorescent reporters between the promoter region of genes encoding a TBDT and the fluorescent reporter mCherry. With these constructs, we can follow the expression of TBDTs under different growth conditions. Mathematical modelling of the data obtained showed the transcription and expression of the gene encoding the TBDT PfeA to have a sigmoidal shape, whereas it was logarithmic for the TBDT gene foxA. Maximum transcription for pfeA was reached in the presence of 3 µM enterobactin, the siderophore recognized by PfeA, whereas the maximum was not reached for foxA with 100 µM nocardamine, the siderophore of FoxA.
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Affiliation(s)
- Thibaut Hubert
- CNRS, UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
- ICube Laboratory, CNRS, UMR 7357, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France
| | - Morgan Madec
- ICube Laboratory, CNRS, UMR 7357, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France.
| | - Isabelle J Schalk
- CNRS, UMR7242, ESBS, University of Strasbourg, Bld Sébastien Brant, 67412, Illkirch, Strasbourg, France.
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11
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Rosa-Núñez E, Echavarri-Erasun C, Armas AM, Escudero V, Poza-Carrión C, Rubio LM, González-Guerrero M. Iron Homeostasis in Azotobacter vinelandii. BIOLOGY 2023; 12:1423. [PMID: 37998022 PMCID: PMC10669500 DOI: 10.3390/biology12111423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023]
Abstract
Iron is an essential nutrient for all life forms. Specialized mechanisms exist in bacteria to ensure iron uptake and its delivery to key enzymes within the cell, while preventing toxicity. Iron uptake and exchange networks must adapt to the different environmental conditions, particularly those that require the biosynthesis of multiple iron proteins, such as nitrogen fixation. In this review, we outline the mechanisms that the model diazotrophic bacterium Azotobacter vinelandii uses to ensure iron nutrition and how it adapts Fe metabolism to diazotrophic growth.
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Affiliation(s)
- Elena Rosa-Núñez
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
- Escuela Técnica de Ingeniería Agraria, Alimentaria, y de Biosistemas, Universidad Politécnica de Madrid, Avda. Puerta de Hierro, 2, 28040 Madrid, Spain
| | - Carlos Echavarri-Erasun
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
- Escuela Técnica de Ingeniería Agraria, Alimentaria, y de Biosistemas, Universidad Politécnica de Madrid, Avda. Puerta de Hierro, 2, 28040 Madrid, Spain
| | - Alejandro M. Armas
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - Viviana Escudero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - César Poza-Carrión
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - Luis M. Rubio
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
- Escuela Técnica de Ingeniería Agraria, Alimentaria, y de Biosistemas, Universidad Politécnica de Madrid, Avda. Puerta de Hierro, 2, 28040 Madrid, Spain
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12
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Liu J, Zhao SY, Hu JY, Chen QX, Jiao SM, Xiao HC, Zhang Q, Xu J, Zhao JF, Zhou HB, Zheng JX, Sun PH. Novel Coumarin Derivatives Inhibit the Quorum Sensing System and Iron Homeostasis as Antibacterial Synergists against Pseudomonas aeruginosa. J Med Chem 2023; 66:14735-14754. [PMID: 37874867 DOI: 10.1021/acs.jmedchem.3c01268] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is well-known to cause biofilm-associated drug resistance and infections that often lead to treatment failure. Herein, we reported a dual-acting antibiofilm strategy by inhibiting both the bacterial quorum sensing system and the iron uptake system. A series of coumarin derivatives were synthesized and evaluated, and compound 4t was identified as the most effective biofilm inhibitor (IC50 = 3.6 μM). Further mechanistic studies have confirmed that 4t not only inhibits the QS systems but also competes strongly with pyoverdine as an iron chelator, causing an iron deficiency in P. aeruginosa. Additionally, 4t significantly improved the synergistic antibacterial effects of ciprofloxacin and tobramycin by more than 200-1000-fold compared to the single-dose antibiotic treatments. Therefore, our study has shown that 4t is a potentially novel antibacterial synergist candidate to treat bacterial infections.
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Affiliation(s)
- Jun Liu
- Department of Oncology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510632, P. R. China
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Si-Yu Zhao
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Jia-Yi Hu
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Qiu-Xian Chen
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Shu-Meng Jiao
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Hai-Chuan Xiao
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Qiang Zhang
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Jun Xu
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Jian-Fu Zhao
- Department of Oncology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Hai-Bo Zhou
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Jun-Xia Zheng
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong 510006, P. R. China
| | - Ping-Hua Sun
- Department of Oncology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510632, P. R. China
- College of Pharmacy, Shihezi University, Shihezi, Xinjiang 832099, P. R. China
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
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13
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Wang W, Xia J, Wang Z, Shao Z. Bacterial cell sensing and signaling pathway for external polycyclic aromatic hydrocarbons (PAHs). iScience 2023; 26:107912. [PMID: 37841585 PMCID: PMC10570129 DOI: 10.1016/j.isci.2023.107912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/19/2023] [Accepted: 09/12/2023] [Indexed: 10/17/2023] Open
Abstract
The mechanism by which a bacterial cell senses external nutrients remains largely unknown. In this study, we identified a bacterial cell sensing system for polycyclic aromatic hydrocarbons (PAHs) in a common marine PAH-using bacterium, Cycloclasticus. It consists of an outer membrane receptor (PahS) and a periplasmic protein (PahP) in combination with a two-component sensing system (TCS) that ensures a rapid response to PAH occurrence by directly controlling serial reactions including chemotactic sensing and movement, PAH uptake and intracellular PAH metabolism. PahS protrudes from the cell and acts as a PAH sensor, transducing the PAH signal across the outer membrane to its periplasmic partner PahP, which in turn transduces the PAH signal across the periplasm to a specialized TCS. This sensing system plays a critical role in sensing and promoting the metabolism of PAHs, which can be scavenged by various hydrocarbon-degrading bacteria.
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Affiliation(s)
- Wanpeng Wang
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
- Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen, China
| | - Jingyu Xia
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Zining Wang
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Zongze Shao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
- Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen, China
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14
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Rivera M. Mobilization of iron stored in bacterioferritin, a new target for perturbing iron homeostasis and developing antibacterial and antibiofilm molecules. J Inorg Biochem 2023; 247:112306. [PMID: 37451083 DOI: 10.1016/j.jinorgbio.2023.112306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/08/2023] [Accepted: 06/24/2023] [Indexed: 07/18/2023]
Abstract
Antibiotic resistance is a global public health threat. The care of chronic infections is complicated by bacterial biofilms. Biofilm embedded cells can be up to 1000-fold more tolerant to antibiotic treatment than planktonic cells. Antibiotic tolerance is a condition which does not involve mutation and enables bacteria to survive in the presence of antibiotics. The antibiotic tolerance of biofilm-cells often renders antibiotics ineffective, even against strains that do not carry resistance-impairing mutations. This review discusses bacterial iron homeostasis and the strategies being developed to target this bacterial vulnerability, with emphasis on a recently proposed approach which aims at targeting the iron storage protein bacterioferritin (Bfr) and its physiological partner, the ferredoxin Bfd. Bfr regulates cytosolic iron concentrations by oxidizing Fe2+ and storing Fe3+ in its internal cavity, and by forming a complex with Bfd to reduce Fe3+ in the internal cavity and release Fe2+ to the cytosol. Blocking the Bfr-Bfd complex in P. aeruginosa cells causes an irreversible accumulation of Fe3+ in BfrB and simultaneous cytosolic iron depletion, which leads to impaired biofilm maintenance and biofilm cell death. Recently discovered small molecule inhibitors of the Bfr-Bfd complex, which bind Bfr at the Bfd binding site, inhibit iron mobilization, and elicit biofilm cell death.
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Affiliation(s)
- Mario Rivera
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, LA 70803, USA.
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15
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Wang X, Xia B, Hao Z, Kang H, Liu W, Chen Y, Jiang Q, Liu J, Gou J, Dong B, Wee ATS, Liu Y, Wei D. A closed-loop catalytic nanoreactor system on a transistor. SCIENCE ADVANCES 2023; 9:eadj0839. [PMID: 37729411 PMCID: PMC10511191 DOI: 10.1126/sciadv.adj0839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 08/17/2023] [Indexed: 09/22/2023]
Abstract
Precision chemistry demands miniaturized catalytic systems for sophisticated reactions with well-defined pathways. An ideal solution is to construct a nanoreactor system functioning as a chemistry laboratory to execute a full chemical process with molecular precision. However, existing nanoscale catalytic systems fail to in situ control reaction kinetics in a closed-loop manner, lacking the precision toward ultimate reaction efficiency. We find an inter-electrochemical gating effect when operating DNA framework-constructed enzyme cascade nanoreactors on a transistor, enabling in situ closed-loop reaction monitoring and modulation electrically. Therefore, a comprehensive system is developed, encapsulating nanoreactors, analyzers, and modulators, where the gate potential modulates enzyme activity and switches cascade reaction "ON" or "OFF." Such electric field-effect property enhances catalytic efficiency of enzyme by 343.4-fold and enables sensitive sarcosine assay for prostate cancer diagnoses, with a limit of detection five orders of magnitude lower than methodologies in clinical laboratory. By coupling with solid-state electronics, this work provides a perspective to construct intelligent nano-systems for precision chemistry.
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Affiliation(s)
- Xuejun Wang
- State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China
- Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Fudan University, Shanghai 200433, China
| | - Binbin Xia
- Institute of Molecular Medicine, Department of Urology, Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Zhuang Hao
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Hua Kang
- State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China
- Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Fudan University, Shanghai 200433, China
| | - Wentao Liu
- State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China
- Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Fudan University, Shanghai 200433, China
| | - Yiheng Chen
- State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China
- Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Fudan University, Shanghai 200433, China
| | - Qunfeng Jiang
- Department of Physics, Fudan University, Shanghai 200433, China
| | - Jingyuan Liu
- Global Clinical Operation, Johnson & Johnson, Shanghai 200233, China
| | - Jian Gou
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
| | - Baijun Dong
- Institute of Molecular Medicine, Department of Urology, Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Andrew Thye Shen Wee
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
| | - Yunqi Liu
- Laboratory of Molecular Materials and Devices, Fudan University, Shanghai 200433, China
| | - Dacheng Wei
- State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China
- Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Laboratory of Molecular Materials and Devices, Fudan University, Shanghai 200433, China
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16
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Olshvang E, Fritsch S, Scholtyssek OC, Schalk IJ, Metzler-Nolte N. Vectorization via Siderophores Increases Antibacterial Activity of K(RW) 3 Peptides against Pseudomonas aeruginosa. Chemistry 2023; 29:e202300364. [PMID: 37541431 DOI: 10.1002/chem.202300364] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Indexed: 08/06/2023]
Abstract
A series of new conjugates comprised from a small synthetic antimicrobial peptide (AMP) and a siderophore-type vector component was designed and tested for activity on P. aeruginosa PAO1 and several genetically modified strains. As AMP, the well-established arginine-tryptophane combination K(RW)3 (P1) was chosen with an added lysine for siderophore attachment. This peptide is easy to prepare, modify, and possesses good anti-bacterial activity. On the vector part, we examined several moieties: (i) the natural siderophore deferoxamine (DFO); (ii) bidentate iron chelators based on the hydroxamate building block (4 a-c) ; (iii) the non-siderophore chelators deferasirox (DFX) and deferiprone-carboxylate (DFP-COOH). All conjugates were prepared by solid phase synthesis techniques and fully characterized by HPLC and mass spectrometry (including HR-MS). 55 Fe uptake assays indicate a receptor-mediated uptake for 4 a-c, DFP-COOH and DFO, which is dependent on the outer membrane transporter FoxA in the case of DFO. All conjugates showed increased antibacterial activity against P. aeruginosa compared to the parent peptide P1 alone when investigated in iron-depleted medium. MIC values were as low as 2 μM (for P1-DFP) on wild type P. aeruginosa. The activity of P1-DFO and P1-DFP was even better on genetically mutated strains unable to produce siderophores (down to 0.5 μM). Although the DFX vector on its own was not able to transport iron inside the bacterial cell as shown by 55 Fe uptake studies, the P1-DFX conjugate had excellent antibacterial activity compared to P1 (2 μM, and as low as 0.25 μM on a receptor-deficient strain unable to produce siderophores), suggesting that the conjugates were indeed recognized and internalized by an (unknown) transporter. Control experiments with an equimolar mixture of P1 and DFX confirm that the observed activity is intrinsic to vectorization. This work thus demonstrates the power of linking small AMPs covalently to siderophores for a new class of Trojan Horse antibiotics, with P1-DFP and P1-DFX being the most potent conjugates.
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Affiliation(s)
- Evgenia Olshvang
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry I - Bioinorganic Chemistry, Ruhr University Bochum, Bochum, Germany
| | - Sarah Fritsch
- UMR7242, ESBS, University of Strasbourg, 67413, Illkirch, Strasbourg, France
- UMR7242, ESBS, CNRS, 67413, Illkirch, Strasbourg, France
| | - Oliver C Scholtyssek
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry I - Bioinorganic Chemistry, Ruhr University Bochum, Bochum, Germany
| | - Isabelle J Schalk
- UMR7242, ESBS, University of Strasbourg, 67413, Illkirch, Strasbourg, France
- UMR7242, ESBS, CNRS, 67413, Illkirch, Strasbourg, France
| | - Nils Metzler-Nolte
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry I - Bioinorganic Chemistry, Ruhr University Bochum, Bochum, Germany
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17
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Wei X, Gao J, Xu C, Pan X, Jin Y, Bai F, Cheng Z, Lamont IL, Pletzer D, Wu W. Murepavadin induces envelope stress response and enhances the killing efficacies of β-lactam antibiotics by impairing the outer membrane integrity of Pseudomonas aeruginosa. Microbiol Spectr 2023; 11:e0125723. [PMID: 37668398 PMCID: PMC10581190 DOI: 10.1128/spectrum.01257-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/08/2023] [Indexed: 09/06/2023] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen that can cause a variety of acute and chronic infections. The bacterium is highly resistant to numerous antibiotics. Murepavadin is a peptidomimetic antibiotic that blocks the function of P. aeruginosa lipopolysaccharide (LPS) transport protein D (LptD), thus inhibiting the insertion of LPS into the outer membrane. In this study, we demonstrated that sublethal concentrations of murepavadin enhance the bacterial outer membrane permeability. Proteomic analyses revealed the alteration of protein composition in bacterial inner and outer membranes following murepavadin treatment. The antisigma factor MucA was upregulated by murepavadin. In addition, the expression of the sigma E factor gene algU and the alginate synthesis gene algD was induced by murepavadin. Deletion of the algU gene reduces bacterial survival following murepavadin treatment, indicating a role of the envelope stress response in bacterial tolerance. We further demonstrated that murepavadin enhances the bactericidal activities of β-lactam antibiotics by promoting drug influx across the outer membrane. In a mouse model of acute pneumonia, the murepavadin-ceftazidime/avibactam combination showed synergistic therapeutic effect against P. aeruginosa infection. In addition, the combination of murepavadin with ceftazidime/avibactam slowed down the resistance development. In conclusion, our results reveal the response mechanism of P. aeruginosa to murepavadin and provide a promising antibiotic combination for the treatment of P. aeruginosa infections.IMPORTANCEThe ever increasing resistance of bacteria to antibiotics poses a serious threat to global public health. Novel antibiotics and treatment strategies are urgently needed. Murepavadin is a novel antibiotic that blocks the assembly of lipopolysaccharide (LPS) into the Pseudomonas aeruginosa outer membrane by inhibiting LPS transport protein D (LptD). Here, we demonstrated that murepavadin impairs bacterial outer membrane integrity, which induces the envelope stress response. We further found that the impaired outer membrane integrity increases the influx of β-lactam antibiotics, resulting in enhanced bactericidal effects. In addition, the combination of murepavadin and a β-lactam/β-lactamase inhibitor mixture (ceftazidime/avibactam) slowed down the resistance development of P. aeruginosa. Overall, this study demonstrates the bacterial response to murepavadin and provides a new combination strategy for effective treatment.
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Affiliation(s)
- Xiaoya Wei
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jiacong Gao
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Congjuan Xu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaolei Pan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Fang Bai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Iain L. Lamont
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Daniel Pletzer
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
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18
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Sánchez-Jiménez A, Llamas MA, Marcos-Torres FJ. Transcriptional Regulators Controlling Virulence in Pseudomonas aeruginosa. Int J Mol Sci 2023; 24:11895. [PMID: 37569271 PMCID: PMC10418997 DOI: 10.3390/ijms241511895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/21/2023] [Accepted: 07/22/2023] [Indexed: 08/13/2023] Open
Abstract
Pseudomonas aeruginosa is a pathogen capable of colonizing virtually every human tissue. The host colonization competence and versatility of this pathogen are powered by a wide array of virulence factors necessary in different steps of the infection process. This includes factors involved in bacterial motility and attachment, biofilm formation, the production and secretion of extracellular invasive enzymes and exotoxins, the production of toxic secondary metabolites, and the acquisition of iron. Expression of these virulence factors during infection is tightly regulated, which allows their production only when they are needed. This process optimizes host colonization and virulence. In this work, we review the intricate network of transcriptional regulators that control the expression of virulence factors in P. aeruginosa, including one- and two-component systems and σ factors. Because inhibition of virulence holds promise as a target for new antimicrobials, blocking the regulators that trigger the production of virulence determinants in P. aeruginosa is a promising strategy to fight this clinically relevant pathogen.
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Affiliation(s)
| | - María A. Llamas
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain;
| | - Francisco Javier Marcos-Torres
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain;
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19
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Otero-Asman JR, Sánchez-Jiménez A, Bastiaansen KC, Wettstadt S, Civantos C, García-Puente A, Bitter W, Llamas MA. The Prc and CtpA proteases modulate cell-surface signaling activity and virulence in Pseudomonas aeruginosa. iScience 2023; 26:107216. [PMID: 37534181 PMCID: PMC10392083 DOI: 10.1016/j.isci.2023.107216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/17/2023] [Accepted: 06/22/2023] [Indexed: 08/04/2023] Open
Abstract
Cell-surface signaling (CSS) is a signal transfer system of Gram-negative bacteria that produces the activation of an extracytoplasmic function σ factor (σECF) in the cytosol in response to an extracellular signal. Activation requires the regulated and sequential proteolysis of the σECF-associated anti-σ factor, and the function of the Prc and RseP proteases. In this work, we have identified another protease that modulates CSS activity, namely the periplasmic carboxyl-terminal processing protease CtpA. CtpA functions upstream of Prc in the proteolytic cascade and seems to prevent the Prc-mediated proteolysis of the CSS anti-σ factor. Importantly, using zebrafish embryos and the A549 lung epithelial cell line as hosts, we show that mutants in the rseP and ctpA proteases of the human pathogen Pseudomonas aeruginosa are considerably attenuated in virulence while the prc mutation increases virulence likely by enhancing the production of membrane vesicles.
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Affiliation(s)
- Joaquín R. Otero-Asman
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Ana Sánchez-Jiménez
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Karlijn C. Bastiaansen
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
- Department of Medical Microbiology and Infection Control, Amsterdam University medical centres, location VU University, 1081 HV Amsterdam, The Netherlands
| | - Sarah Wettstadt
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Cristina Civantos
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Alicia García-Puente
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Wilbert Bitter
- Department of Medical Microbiology and Infection Control, Amsterdam University medical centres, location VU University, 1081 HV Amsterdam, The Netherlands
| | - María A. Llamas
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
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20
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Anne F, Gwenaëlle G, Isabelle S, Pierre F. Improved engineering of Pseudomonas aeruginosa to study the adaptation of pyoverdine production under intra- or inter- specific bacterial competition. J Microbiol Methods 2023; 210:106753. [PMID: 37271375 DOI: 10.1016/j.mimet.2023.106753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 04/27/2023] [Accepted: 05/28/2023] [Indexed: 06/06/2023]
Abstract
Pseudomonas aeruginosa (PA) is a common cause of chronic infections, particularly feared by cystic fibrosis patients. PA colonizes the lung where it adapts to the local environment, and/or to treatments by drugs. This genotypic and phenotypic adaptation, in turns, influences its interaction with its environment, like bacteria from the microbiota. As an example, to access iron, PA produces and secretes two siderophores, pyoverdine and pyochelin that are iron chelators scavenging iron from the environment and bringing it back into the bacterial cells. Siderophores production depends on the level of iron starvation, on the presence of other bacteria, etc. this latter component being less well investigated. Even if studies on bacterial interactions, and their evolution, have been increasing since several years, we are still facing a lack of tools, for example, to specifically follow the growth of PA isolates in such competitive environments. We thus improved a cloning method to gain time in the cloning steps, to lower the polar effects, and to accurately follow the interactions of any PA isolate with other bacteria. For that, a fluorescent reporter gene was inserted between two genes, the glutamine-fructose-6-phosphate transaminase (glmS) and PA5548. This reporter was efficiently produced either from an inducible or a house-keeping promoter, and its expression did not lead to polar effects. We used this strain to study intra and inter-specific bacterial competitions for iron between different lung pathogens. We thus grew wild-type PA together either with an isogenic PA ΔpvdS variant, that does not produce the most efficient siderophore pyoverdine, or with Klebsiella pneumoniae or Acinetobacter baumanii, two other lung pathogens. We finally monitored the effect of the loss of pvdS on the competition between PA and the other bacterial species. These studies enabled us to differentiate intra from inter specific competitions, both arising in the lung environment, and pinpoint the importance of the bacterial specie for the adaptation of pyoverdine production.
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Affiliation(s)
- Forster Anne
- Université de Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France; CNRS, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg, France
| | - Graulier Gwenaëlle
- Université de Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France; CNRS, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg, France
| | - Schalk Isabelle
- Université de Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France; CNRS, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg, France
| | - Fechter Pierre
- Université de Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France; CNRS, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg, France.
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21
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Cornelis P, Tahrioui A, Lesouhaitier O, Bouffartigues E, Feuilloley M, Baysse C, Chevalier S. High affinity iron uptake by pyoverdine in Pseudomonas aeruginosa involves multiple regulators besides Fur, PvdS, and FpvI. Biometals 2023; 36:255-261. [PMID: 35171432 DOI: 10.1007/s10534-022-00369-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/03/2022] [Indexed: 11/02/2022]
Abstract
Pseudomonas aeruginosa is a Gram-negative bacterium which can cause serious infections among immune-depressed people including cystic fibrosis patients where it can colonize the lungs causing chronic infections. Iron is essential for P. aeruginosa and can be provided via three sources under aerobic conditions: its own siderophores pyochelin (PCH) and pyoverdine (PVD), xenosiderophores, or heme, respectively. Pyoverdine is the high affinity siderophore and its synthesis and uptake involve more than 30 genes organized in different operons. Its synthesis and uptake are triggered by iron scarcity via the Fur regulator and involves two extra cytoplasmic sigma factors (ECF), PvdS for the biosynthesis of PVD and FpvI for the uptake via the TonB-dependent FpvA outer membrane transporter and other periplasmic and inner membrane proteins. It appeared recently that the regulation of PVD biosynthesis and uptake involves other regulators, including other ECF factors, and LysR regulators. This is the case especially for the genes coding for periplasmic and inner membrane proteins involved in the reduction of Fe3+ to Fe2+ and the transport of ferrous iron to the cytoplasm that appears to represent a crucial step in the uptake process.
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Affiliation(s)
- Pierre Cornelis
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France.
- Laboratorium Microbiologie, Vrije Universiteit Brussel, Brussels, Belgium.
| | - Ali Tahrioui
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Olivier Lesouhaitier
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Emeline Bouffartigues
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Marc Feuilloley
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Christine Baysse
- CNRS, Institut de Génétique et de Développement de Rennes (IGDR), UMR6290, Université de Rennes, Rennes, France
| | - Sylvie Chevalier
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
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22
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Sánchez-Jiménez A, Marcos-Torres FJ, Llamas MA. Mechanisms of iron homeostasis in Pseudomonas aeruginosa and emerging therapeutics directed to disrupt this vital process. Microb Biotechnol 2023. [PMID: 36857468 DOI: 10.1111/1751-7915.14241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/13/2023] [Indexed: 03/03/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen able to infect any human tissue. One of the reasons for its high adaptability and colonization of host tissues is its capacity of maintaining iron homeostasis through a wide array of iron acquisition and removal mechanisms. Due to their ability to cause life-threatening acute and chronic infections, especially among cystic fibrosis and immunocompromised patients, and their propensity to acquire resistance to many antibiotics, the World Health Organization (WHO) has encouraged the scientific community to find new strategies to eradicate this pathogen. Several recent strategies to battle P. aeruginosa focus on targeting iron homeostasis mechanisms, turning its greatest advantage into an exploitable weak point. In this review, we discuss the different mechanisms used by P. aeruginosa to maintain iron homeostasis and the strategies being developed to fight this pathogen by blocking these mechanisms. Among others, the use of iron chelators and mimics, as well as disruption of siderophore production and uptake, have shown promising results in reducing viability and/or virulence of this pathogen. The so-called 'Trojan-horse' strategy taking advantage of the siderophore uptake systems is emerging as an efficient method to improve delivery of antibiotics into the bacterial cells. Moreover, siderophore transporters are considered promising targets for the developing of P. aeruginosa vaccines.
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Affiliation(s)
- Ana Sánchez-Jiménez
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Francisco J Marcos-Torres
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - María A Llamas
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
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23
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Bernal P, Civantos C, Pacheco-Sánchez D, Quesada JM, Filloux A, Llamas MA. Transcriptional organization and regulation of the Pseudomonas putida K1 type VI secretion system gene cluster. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001295. [PMID: 36748579 PMCID: PMC9993120 DOI: 10.1099/mic.0.001295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The type VI secretion system (T6SS) is an antimicrobial molecular weapon that is widespread in Proteobacteria and offers competitive advantages to T6SS-positive micro-organisms. Three T6SSs have recently been described in Pseudomonas putida KT2440 and it has been shown that one, K1-T6SS, is used to outcompete a wide range of phytopathogens, protecting plants from pathogen infections. Given the relevance of this system as a powerful and innovative mechanism of biological control, it is critical to understand the processes that govern its expression. Here, we experimentally defined two transcriptional units in the K1-T6SS cluster. One encodes the structural components of the system and is transcribed from two adjacent promoters. The other encodes two hypothetical proteins, the tip of the system and the associated adapters, and effectors and cognate immunity proteins, and it is also transcribed from two adjacent promoters. The four identified promoters contain the typical features of σ70-dependent promoters. We have studied the expression of the system under different conditions and in a number of mutants lacking global regulators. P. putida K1-T6SS expression is induced in the stationary phase, but its transcription does not depend on the stationary σ factor RpoS. In fact, the expression of the system is indirectly repressed by RpoS. Furthermore, it is also repressed by RpoN and the transcriptional regulator FleQ, an enhancer-binding protein typically acting in conjunction with RpoN. Importantly, expression of the K1-T6SS gene cluster is positively regulated by the GacS-GacA two-component regulatory system (TCS) and repressed by the RetS sensor kinase, which inhibits this TCS. Our findings identified a complex regulatory network that governs T6SS expression in general and P. putida K1-T6SS in particular, with implications for controlling and manipulating a bacterial agent that is highly relevant in biological control.
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Affiliation(s)
- Patricia Bernal
- Department of Environmental Protection, Estación Experimental del Zaidín (CSIC), Granada, Spain.,MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, UK.,Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Cristina Civantos
- Department of Environmental Protection, Estación Experimental del Zaidín (CSIC), Granada, Spain
| | - Daniel Pacheco-Sánchez
- Department of Environmental Protection, Estación Experimental del Zaidín (CSIC), Granada, Spain
| | - José M Quesada
- Department of Environmental Protection, Estación Experimental del Zaidín (CSIC), Granada, Spain
| | - Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, UK.,Singapore Centre for Environmental Life Sciences Engineering. Nanyang Technological University, Singapore
| | - María A Llamas
- Department of Environmental Protection, Estación Experimental del Zaidín (CSIC), Granada, Spain
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24
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Schalk IJ, Perraud Q. Pseudomonas aeruginosa and its multiple strategies to access iron. Environ Microbiol 2022; 25:811-831. [PMID: 36571575 DOI: 10.1111/1462-2920.16328] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/21/2022] [Indexed: 12/27/2022]
Abstract
Pseudomonas aeruginosa is a ubiquitous bacterium found in many natural and man-made environments. It is also a pathogen for plants, animals, and humans. As for almost all living organisms, iron is an essential nutrient for the growth of P. aeruginosa. The bacterium has evolved complex systems to access iron and maintain its homeostasis to survive in diverse natural and dynamic host environments. To access ferric iron, P. aeruginosa is able to produce two siderophores (pyoverdine and pyochelin), as well as use a variety of siderophores produced by other bacteria (mycobactins, enterobactin, ferrioxamine, ferrichrome, vibriobactin, aerobactin, rhizobactin and schizokinen). Furthermore, it can also use citrate, in addition to catecholamine neuromediators and plant-derived mono catechols, as siderophores. The P. aeruginosa genome also encodes three heme-uptake pathways (heme being an iron source) and one ferrous iron acquisition pathway. This review aims to summarize current knowledge concerning the molecular mechanisms involved in all the iron and heme acquisition strategies used by P. aeruginosa.
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Affiliation(s)
- Isabelle J Schalk
- CNRS, UMR7242, ESBS, Strasbourg, France.,University of Strasbourg, UMR7242, ESBS, Strasbourg, France
| | - Quentin Perraud
- CNRS, UMR7242, ESBS, Strasbourg, France.,University of Strasbourg, UMR7242, ESBS, Strasbourg, France
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25
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The Alginate and Motility Regulator AmrZ is Essential for the Regulation of the Dispersion Response by Pseudomonas aeruginosa Biofilms. mSphere 2022; 7:e0050522. [PMID: 36374041 PMCID: PMC9769550 DOI: 10.1128/msphere.00505-22] [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] [Indexed: 11/16/2022] Open
Abstract
Dispersion is an active process exhibited by Pseudomonas aeruginosa during the late stages of biofilm development or in response to various cues, including nitric oxide and glutamate. Upon cue sensing, biofilm cells employ enzymes that actively degrade the extracellular matrix, thereby allowing individual cells to become liberated. While the mechanism by which P. aeruginosa senses and relays dispersion cues has been characterized, little is known about how dispersion cue sensing mechanisms result in matrix degradation. Considering that the alginate and motility regulator AmrZ has been reported to regulate genes that play a role in dispersion, including those affecting virulence, c-di-GMP levels, Pel and Psl abundance, and motility, we asked whether AmrZ contributes to the regulation of dispersion. amrZ was found to be significantly increased in transcript abundance under dispersion-inducing conditions, with the inactivation of amrZ impairing dispersion by P. aeruginosa biofilms in response to glutamate and nitric oxide. While the overexpression of genes encoding matrix-degrading enzymes pelA, pslG, and/or endA resulted in the dispersion of wild-type biofilms, similar conditions failed to disperse biofilms formed by dtamrZ. Likewise, the inactivation of amrZ abrogated the hyperdispersive phenotype of PAO1/pJN-bdlA_G31A biofilms, with dtamrZ-impaired dispersion being independent of the expression, production, and activation of BdlA. Instead, dispersion was found to require the AmrZ-target genes napB and PA1891. Our findings indicate that AmrZ is essential for the regulation of dispersion by P. aeruginosa biofilms, functions downstream of BdlA postdispersion cue sensing, and regulates the expression of genes contributing to biofilm matrix degradation as well as napB and PA1891. IMPORTANCE In P. aeruginosa, biofilm dispersion has been well-characterized with respect to dispersion cue perception, matrix degradation, and the consequences of dispersion. While the intracellular signaling molecule c-di-GMP has been linked to many of the phenotypic changes ascribed to dispersion, including the modulation of motility and matrix production, little is known about the regulatory mechanisms leading to matrix degradation and cells actively leaving the biofilm. In this study, we report for the first time an essential role of the transcriptional regulator AmrZ and two AmrZ-dependent genes, napB, and PA1891, in the dispersion response, thereby linking dispersion cue sensing via BdlA to the regulation of matrix degradation and to the ultimate liberation of bacterial cells from the biofilm.
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26
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Yan H, Ren Y, Zhou B, Ye F, Wu Z. Microbial profile of T-shirts after a fitness session of Chinese students. Heliyon 2022; 8:e12379. [PMID: 36582726 PMCID: PMC9793269 DOI: 10.1016/j.heliyon.2022.e12379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/02/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
Clothing textiles could protect our human skin against external factors, but the microbial population, including conditional pathogens, in clothing, would cause unpleasant odor, Skin inflammation, and textile deterioration. Several studies have reported that microbiomes on clothes are affected by skin microorganisms of individuals, the local environment and the types of textile fabrics, but little is known about how the textile microbial community is shaped in the Chinese population. In this study, 10 healthy young students were recruited to successfully wear the T-shirts made with 3 different fabrics (polyester, cotton, and blending fabrics of polyester and cotton) during physical exercise. Total deoxyribonucleic acid (DNA) was extracted from 30 T-shirts and 16s rRNA gene amplicon sequencing was applied to estimate the absolute abundances of bacteria in the samples. The main bacteria on wore T-shirts were Staphylococcus (21.66%) Enhydrobacter (13.81%), Pantoea (8.14%), Acinetobacter (7.81%), Pseudomonas (6.18%), Cutibacterium (4.99%). However, no difference of α and β diversity was observed among the three textile fabrics. Further analysis found that Pantoea and Pseudomonas, mainly from the environment, enriched on the polyester, but not on cotton, while Enhydrobacter, from human skin, has the growth advantage on cotton, and the blending fabric in between. Collectively, our study preliminary explored the clothes microbiome in Chinese young students, contributing to helping understand the role of clothing microorganisms on human health.
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Affiliation(s)
- Huizhen Yan
- Department of Occupational & Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China,Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Yuxing Ren
- Department of Occupational & Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China,Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Bihong Zhou
- Guangzhou Blue Moon Industrial Co., Ltd., Guangzhou, Guangdong, China
| | - Fang Ye
- Department of Occupational & Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China,Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China,Corresponding author.
| | - Zhigang Wu
- Department of Occupational & Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China,Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China,Corresponding author.
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27
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A Review of Pseudomonas aeruginosa Metallophores: Pyoverdine, Pyochelin and Pseudopaline. BIOLOGY 2022; 11:biology11121711. [PMID: 36552220 PMCID: PMC9774294 DOI: 10.3390/biology11121711] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022]
Abstract
P. aeruginosa is a common Gram-negative bacterium found in nature that causes severe infections in humans. As a result of its natural resistance to antibiotics and the ability of biofilm formation, the infection with this pathogen can be therapeutic challenging. During infection, P. aeruginosa produces secondary metabolites such as metallophores that play an important role in their virulence. Metallophores are metal ions chelating molecules secreted by bacteria, thus allowing them to survive in the host under metal scarce conditions. Pyoverdine, pyochelin and pseudopaline are the three metallophores secreted by P. aeruginosa. Pyoverdines are the primary siderophores that acquire iron from the surrounding medium. These molecules scavenge and transport iron to the bacterium intracellular compartment. Pyochelin is another siderophore produced by this bacterium, but in lower quantities and its affinity for iron is less than that of pyoverdine. The third metallophore, pseudopaline, is an opine narrow spectrum ion chelator that enables P. aeruginosa to uptake zinc in particular but can transport nickel and cobalt as well. This review describes all the aspects related to these three metallophore, including their main features, biosynthesis process, secretion and uptake when loaded by metals, in addition to the genetic regulation responsible for their synthesis and secretion.
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28
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Stringent Starvation Protein SspA and Iron Starvation Sigma Factor PvdS Coordinately Regulate Iron Uptake and Prodiginine Biosynthesis in
Pseudoalteromonas
sp. R3. Appl Environ Microbiol 2022; 88:e0116422. [PMID: 36326244 PMCID: PMC9680616 DOI: 10.1128/aem.01164-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Both deficiency and excess of intracellular iron can be harmful, and thus, the iron homeostasis needs to be tightly regulated in organisms. At present, the ferric uptake regulator (Fur) is the best-characterized regulator involved in bacterial iron homeostasis, while other regulators of iron homeostasis remain to be further explored.
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29
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Calero P, Gurdo N, Nikel PI. Role of the CrcB transporter of Pseudomonas putida in the multi-level stress response elicited by mineral fluoride. Environ Microbiol 2022; 24:5082-5104. [PMID: 35726888 PMCID: PMC9796867 DOI: 10.1111/1462-2920.16110] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 01/07/2023]
Abstract
The presence of mineral fluoride (F- ) in the environment has both a geogenic and anthropogenic origin, and the halide has been described to be toxic in virtually all living organisms. While the evidence gathered in different microbial species supports this notion, a systematic exploration of the effects of F- salts on the metabolism and physiology of environmental bacteria remained underexplored thus far. In this work, we studied and characterized tolerance mechanisms deployed by the model soil bacterium Pseudomonas putida KT2440 against NaF. By adopting systems-level omic approaches, including functional genomics and metabolomics, we gauged the impact of this anion at different regulatory levels under conditions that impair bacterial growth. Several genes involved in halide tolerance were isolated in a genome-wide Tn-Seq screening-among which crcB, encoding an F- -specific exporter, was shown to play the predominant role in detoxification. High-resolution metabolomics, combined with the assessment of intracellular and extracellular pH values and quantitative physiology experiments, underscored the key nodes in central carbon metabolism affected by the presence of F- . Taken together, our results indicate that P. putida undergoes a general, multi-level stress response when challenged with NaF that significantly differs from that caused by other saline stressors. While microbial stress responses to saline and oxidative challenges have been extensively studied and described in the literature, very little is known about the impact of fluoride (F- ) on bacterial physiology and metabolism. This state of affairs contrasts with the fact that F- is more abundant than other halides in the Earth crust (e.g. in some soils, the F- concentration can reach up to 1 mg gsoil -1 ). Understanding the global effects of NaF treatment on bacterial physiology is not only relevant to unveil distinct mechanisms of detoxification but it could also guide microbial engineering approaches for the target incorporation of fluorine into value-added organofluorine molecules. In this regard, the soil bacterium P. putida constitutes an ideal model to explore such scenarios, since this species is particularly known for its high level of stress resistance against a variety of physicochemical perturbations.
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Affiliation(s)
- Patricia Calero
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkKongens LyngbyDenmark
| | - Nicolás Gurdo
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkKongens LyngbyDenmark
| | - Pablo I. Nikel
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkKongens LyngbyDenmark
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30
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Donegan RK. The role of host heme in bacterial infection. Biol Chem 2022; 403:1017-1029. [PMID: 36228088 DOI: 10.1515/hsz-2022-0192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 09/14/2022] [Indexed: 11/15/2022]
Abstract
Heme is an indispensable cofactor for almost all aerobic life, including the human host and many bacterial pathogens. During infection, heme and hemoproteins are the largest source of bioavailable iron, and pathogens have evolved various heme acquisition pathways to satisfy their need for iron and heme. Many of these pathways are regulated transcriptionally by intracellular iron levels, however, host heme availability and intracellular heme levels have also been found to regulate heme uptake in some species. Knowledge of these pathways has helped to uncover not only how these bacteria incorporate host heme into their metabolism but also provided insight into the importance of host heme as a nutrient source during infection. Within this review is covered multiple aspects of the role of heme at the host pathogen interface, including the various routes of heme biosynthesis, how heme is sequestered by the host, and how heme is scavenged by bacterial pathogens. Also discussed is how heme and hemoproteins alter the behavior of the host immune system and bacterial pathogens. Finally, some unanswered questions about the regulation of heme uptake and how host heme is integrated into bacterial metabolism are highlighted.
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Affiliation(s)
- Rebecca K Donegan
- Department of Chemistry, Barnard College, 3009 Broadway, New York, NY, 10027, USA
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31
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Dostert M, Belanger CR, Pedraz L, Alford MA, Blimkie TM, Falsafi RF, Bains M, Dhillon BK, Haney CH, Lee AH, Hancock REW. BosR: A novel biofilm-specific regulator in Pseudomonas aeruginosa. Front Microbiol 2022; 13:1021021. [PMID: 36312952 PMCID: PMC9611778 DOI: 10.3389/fmicb.2022.1021021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Biofilms are the most common cause of bacterial infections in humans and notoriously hard to treat due to their ability to withstand antibiotics and host immune defenses. To overcome the current lack of effective antibiofilm therapies and guide future design, the identification of novel biofilm-specific gene targets is crucial. In this regard, transcriptional regulators have been proposed as promising targets for antimicrobial drug design. Therefore, a Transposon insertion sequencing approach was employed to systematically identify regulators phenotypically affecting biofilm growth in Pseudomonas aeruginosa PA14 using the TnSeq analysis tools Bio-TraDIS and TRANSIT. A screen of a pool of 300,000 transposon insertion mutants identified 349 genes involved in biofilm growth on hydroxyapatite, including 47 regulators. Detection of 19 regulatory genes participating in well-established biofilm pathways validated the results. An additional 28 novel prospective biofilm regulators suggested the requirement for multiple one-component transcriptional regulators. Biofilm-defective phenotypes were confirmed for five one-component transcriptional regulators and a protein kinase, which did not affect motility phenotypes. The one-component transcriptional regulator bosR displayed a conserved role in P. aeruginosa biofilm growth since its ortholog in P. aeruginosa strain PAO1 was also required for biofilm growth. Microscopic analysis of a chromosomal deletion mutant of bosR confirmed the role of this regulator in biofilm growth. Overall, our results highlighted that the gene network driving biofilm growth is complex and involves regulators beyond the primarily studied groups of two-component systems and cyclic diguanylate signaling proteins. Furthermore, biofilm-specific regulators, such as bosR, might constitute prospective new drug targets to overcome biofilm infections.
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Affiliation(s)
- Melanie Dostert
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Corrie R. Belanger
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Lucas Pedraz
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Morgan A. Alford
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Travis M. Blimkie
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Reza F. Falsafi
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Manjeet Bains
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Bhavjinder Kaur Dhillon
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Cara H. Haney
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Amy H. Lee
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
- *Correspondence: Robert E. W. Hancock,
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High-Level Expression of Cell-Surface Signaling System Hxu Enhances Pseudomonas aeruginosa Bloodstream Infection. Infect Immun 2022; 90:e0032922. [PMID: 36169312 PMCID: PMC9584290 DOI: 10.1128/iai.00329-22] [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: 11/20/2022] Open
Abstract
Bloodstream infections (BSIs) caused by Pseudomonas aeruginosa are associated with a high mortality rate in the clinic. However, the fitness mechanisms responsible for the evolution of virulence factors that facilitate the dissemination of P. aeruginosa to the bloodstream are poorly understood. In this study, a transcriptomic analysis of the BSI-associated P. aeruginosa clinical isolates showed a high-level expression of cell-surface signaling (CSS) system Hxu. Whole-genome sequencing and comparative genomics of these isolates showed that a mutation in rnfE gene was responsible for the elevated expression of the Hxu-CSS pathway. Most importantly, deletion of the hxuIRA gene cluster in a laboratory strain PAO1 reduced its BSI capability while overexpression of the HxuIRA pathway promoted BSI in a murine sepsis model. We further demonstrated that multiple components in the blood plasma, including heme, hemoglobin, the heme-scavenging proteins haptoglobin, and hemopexin, as well as the iron-delivery protein transferrin, could activate the Hxu system. Together, these studies suggested that the Hxu-CSS system was an important signal transduction pathway contributing to the adaptive pathogenesis of P. aeruginosa in BSI.
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Plant-Derived Catechols Are Substrates of TonB-Dependent Transporters and Sensitize Pseudomonas aeruginosa to Siderophore-Drug Conjugates. mBio 2022; 13:e0149822. [PMID: 35770947 PMCID: PMC9426570 DOI: 10.1128/mbio.01498-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen responsible for acute and chronic infections in immunocompromised hosts. This organism is known to compete efficiently against coinfecting microorganisms, due in part to the secretion of antimicrobial molecules and the synthesis of siderophore molecules with high affinity for iron. P. aeruginosa possess a large repertoire of TonB-dependent transporters for the uptake of its own, as well as xenosiderophores released from other bacteria or fungi. Here, we show that P. aeruginosa is also capable of utilizing plant-derived polyphenols as an iron source. We found that exclusively plant-derived phenols containing a catechol group (i.e., chlorogenic acid, caffeic acid, quercetin, luteolin) induce the expression of the TonB-dependent transporters PiuA or PirA. This induction requires the two-component system PirR-PirS. Chlorogenic acid in its Fe(III)-loaded form was actively transported by PiuA and PirA and supported growth under iron-limiting conditions. Coincidentally, PiuA and PirA are also the main TonB transporters for the recently approved siderophore-drug conjugate cefiderocol. Surprisingly, quercetin supplementation increased the susceptibility of P. aeruginosa to siderophore-drug conjugates, due to induction of piuA and pirA expression mediated by the PirR-PirS two-component system. These findings suggest a potential novel therapeutic application for these biologically active dietary polyphenols.
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Fritsch S, Gasser V, Peukert C, Pinkert L, Kuhn L, Perraud Q, Normant V, Brönstrup M, Schalk IJ. Uptake Mechanisms and Regulatory Responses to MECAM- and DOTAM-Based Artificial Siderophores and Their Antibiotic Conjugates in Pseudomonas aeruginosa. ACS Infect Dis 2022; 8:1134-1146. [PMID: 35500104 DOI: 10.1021/acsinfecdis.2c00049] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The development of new antibiotics against Gram-negative bacteria has to deal with the low permeability of the outer membrane. This obstacle can be overcome by utilizing siderophore-dependent iron uptake pathways as entrance routes for antibiotic uptake. Iron-chelating siderophores are actively imported by bacteria, and their conjugation to antibiotics allows smuggling the latter into bacterial cells. Synthetic siderophore mimetics based on MECAM (1,3,5-N,N',N″-tris-(2,3-dihydroxybenzoyl)-triaminomethylbenzene) and DOTAM (1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane) cores, both chelating iron via catechol groups, have been recently applied as versatile carriers of functional cargo. In the present study, we show that MECAM and the MECAM-ampicillin conjugate 3 transport iron into Pseudomonas aeruginosa cells via the catechol-type outer membrane transporters PfeA and PirA and DOTAM solely via PirA. Differential proteomics and quantitative real-time polymerase chain reaction (qRT-PCR) showed that MECAM import induced the expression of pfeA, whereas 3 led to an increase in the expression of pfeA and ampc, a gene conferring ampicillin resistance. The presence of DOTAM did not induce the expression of pirA but upregulated the expression of two zinc transporters (cntO and PA0781), pointing out that bacteria become zinc starved in the presence of this compound. Iron uptake experiments with radioactive 55Fe demonstrated that import of this nutrient by MECAM and DOTAM was as efficient as with the natural siderophore enterobactin. The study provides a functional validation for DOTAM- and MECAM-based artificial siderophore mimetics as vehicles for the delivery of cargo into Gram-negative bacteria.
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Affiliation(s)
- Sarah Fritsch
- CNRS, University of Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg 67070, France
| | - Véronique Gasser
- CNRS, University of Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg 67070, France
| | - Carsten Peukert
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, Braunschweig 38124, Germany
| | - Lukas Pinkert
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, Braunschweig 38124, Germany
| | - Lauriane Kuhn
- Plateforme Proteomique Strasbourg-Esplanade, Institut de Biologie Moléculaire et Cellulaire, CNRS, FR1589, 15 rue Descartes, Strasbourg Cedex F-67084, France
| | - Quentin Perraud
- CNRS, University of Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg 67070, France
| | - Vincent Normant
- CNRS, University of Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg 67070, France
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, Braunschweig 38124, Germany
- German Center for Infection Research (DZIF), Site Hannover-Braunschweig, Braunschweig 38124, Germany
- Center of Biomolecular Drug Research (BMWZ), Leibniz Universität, Hannover 30159, Germany
| | - Isabelle J. Schalk
- CNRS, University of Strasbourg, UMR7242, ESBS, Bld Sébastien Brant, F-67412 Illkirch, Strasbourg 67070, France
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An Extracytoplasmic Function Sigma Factor Required for Full Virulence in Xanthomonas citri pv. citri. J Bacteriol 2022; 204:e0062421. [PMID: 35446118 DOI: 10.1128/jb.00624-21] [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: 11/20/2022] Open
Abstract
The genus Xanthomonas includes more than 30 phytopathogenic species that infect a wide range of plants and cause severe diseases that greatly impact crop productivity. These bacteria are highly adapted to the soil and plant environment, being found in decaying material, as epiphytes, and colonizing the plant mesophyll. Signal transduction mechanisms involved in the responses of Xanthomonas to environmental changes are still poorly characterized. Xanthomonad genomes typically encode several representatives of the extracytoplasmic function σ (σECF) factors, whose physiological roles remain elusive. In this work, we functionally characterized the Xanthomonas citri pv. citri EcfL, a σECF factor homologous to members of the iron-responsive FecI-like group. We show that EcfL is not required or induced during iron starvation, despite presenting the common features of other FecI-like σECF factors. EcfL positively regulates one operon composed of three genes that encode a TonB-dependent receptor involved in cell surface signaling, an acid phosphatase, and a lectin-domain containing protein. Furthermore, we demonstrate that EcfL is required for full virulence in citrus, and its regulon is induced inside the plant mesophyll and in response to acid stress. Together, our study suggests a role for EcfL in the adaptation of X. citri to the plant environment, in this way contributing to its ability to cause citrus canker disease. IMPORTANCE The Xanthomonas genus comprises a large number of phytopathogenic species that infect a wide variety of economically important plants worldwide. Bacterial adaptation to the plant and soil environment relies on their repertoire of signal transduction pathways, including alternative sigma factors of the extracytoplasmic function family (σECF). Here, we describe a new σECF factor found in several Xanthomonas species, demonstrating its role in Xanthomonas citri virulence to citrus plants. We show that EcfL regulates a single operon containing three genes, which are also conserved in other Xanthomonas species. This study further expands our knowledge on the functions of the widespread family of σECF factors in phytopathogenic bacteria.
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Rajput A, Tsunemoto H, Sastry AV, Szubin R, Rychel K, Sugie J, Pogliano J, Palsson BO. Machine learning from Pseudomonas aeruginosa transcriptomes identifies independently modulated sets of genes associated with known transcriptional regulators. Nucleic Acids Res 2022; 50:3658-3672. [PMID: 35357493 PMCID: PMC9023270 DOI: 10.1093/nar/gkac187] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/28/2022] [Accepted: 03/29/2022] [Indexed: 12/16/2022] Open
Abstract
The transcriptional regulatory network (TRN) of Pseudomonas aeruginosa coordinates cellular processes in response to stimuli. We used 364 transcriptomes (281 publicly available + 83 in-house generated) to reconstruct the TRN of P. aeruginosa using independent component analysis. We identified 104 independently modulated sets of genes (iModulons) among which 81 reflect the effects of known transcriptional regulators. We identified iModulons that (i) play an important role in defining the genomic boundaries of biosynthetic gene clusters (BGCs), (ii) show increased expression of the BGCs and associated secretion systems in nutrient conditions that are important in cystic fibrosis, (iii) show the presence of a novel ribosomally synthesized and post-translationally modified peptide (RiPP) BGC which might have a role in P. aeruginosa virulence, (iv) exhibit interplay of amino acid metabolism regulation and central metabolism across different carbon sources and (v) clustered according to their activity changes to define iron and sulfur stimulons. Finally, we compared the identified iModulons of P. aeruginosa with those previously described in Escherichia coli to observe conserved regulons across two Gram-negative species. This comprehensive TRN framework encompasses the majority of the transcriptional regulatory machinery in P. aeruginosa, and thus should prove foundational for future research into its physiological functions.
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Affiliation(s)
- Akanksha Rajput
- Department of Bioengineering, University of California, San Diego, La Jolla, USA
| | - Hannah Tsunemoto
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Anand V Sastry
- Department of Bioengineering, University of California, San Diego, La Jolla, USA
| | - Richard Szubin
- Department of Bioengineering, University of California, San Diego, La Jolla, USA
| | - Kevin Rychel
- Department of Bioengineering, University of California, San Diego, La Jolla, USA
| | - Joseph Sugie
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Joe Pogliano
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, USA.,Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kongens, Lyngby, Denmark
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37
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Grove A. Extracytoplasmic Function Sigma Factors Governing Production of the Primary Siderophores in Pathogenic Burkholderia Species. Front Microbiol 2022; 13:851011. [PMID: 35283809 PMCID: PMC8908255 DOI: 10.3389/fmicb.2022.851011] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Bacteria respond to changing environments by modulating their gene expression programs. One of the mechanisms by which this may be accomplished is by substituting the primary σ factor with an alternative σ factor belonging to the family of extracytoplasmic function (ECF) σ factors. ECF σ factors are activated only in presence of specific signals, and they direct the RNA polymerase (RNAP) to transcribe a defined subset of genes. One condition, which may trigger the activation of an ECF σ factor, is iron limitation. To overcome iron starvation, bacteria produce and secrete siderophores, which chelate iron and facilitate its cellular uptake. In the genus Burkholderia, which includes several serious human pathogens, uptake of iron is critical for virulence, and expression of biosynthetic gene clusters encoding proteins involved in synthesis and transport of the primary siderophores are under control of an ECF σ factor. This review summarizes mechanisms involved in regulation of these gene clusters, including the role of global transcriptional regulators. Since siderophore-mediated iron acquisition is important for virulence, interference with this process constitutes a viable approach to the treatment of bacterial infections.
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Affiliation(s)
- Anne Grove
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
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38
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Cai Z, Yang F, Shao X, Yue Z, Li Z, Song Y, Pan X, Jin Y, Cheng Z, Ha UH, Feng J, Yang L, Deng X, Wu W, Bai F. ECF Sigma Factor HxuI Is Critical for In Vivo Fitness of Pseudomonas aeruginosa during Infection. Microbiol Spectr 2022; 10:e0162021. [PMID: 35044199 PMCID: PMC8768829 DOI: 10.1128/spectrum.01620-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/04/2022] [Indexed: 11/22/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa often adapts to its host environment and causes recurrent nosocomial infections. The extracytoplasmic function (ECF) sigma factor enables bacteria to alter their gene expression in response to host environmental stimuli. Here, we report an ECF sigma factor, HxuI, which is rapidly induced once P. aeruginosa encounters the host. Host stresses such as iron limitation, oxidative stress, low oxygen, and nitric oxide induce the expression of hxuI. By combining RNA-seq and promoter-lacZ reporter fusion analysis, we reveal that HxuI can activate the expression of diverse metabolic and virulence pathways which are critical to P. aeruginosa infections, including iron acquisition, denitrification, pyocyanin synthesis, and bacteriocin production. Most importantly, overexpression of the hxuI in the laboratory strain PAO1 promotes its colonization in both murine lung and subcutaneous infections. Together, our findings show that HxuI, a key player in host stress-response, controls the in vivo adaptability and virulence of P. aeruginosa during infection. IMPORTANCE P. aeruginosa has a strong ability to adapt to diverse environments, making it capable of causing recurrent and multisite infections in clinics. Understanding host adaptive mechanisms plays an important guiding role in the development of new anti-infective agents. Here, we demonstrate that an ECFσ factor of P. aeruginosa response to the host-inflicted stresses, which promotes the bacterial in vivo fitness and pathogenicity. Furthermore, our findings may help explain the emergence of highly transmissible strains of P. aeruginosa and the acute exacerbations during chronic infections.
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Affiliation(s)
- Zeqiong Cai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Fan Yang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaolong Shao
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Zhuo Yue
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Zhenpeng Li
- School of Laboratory Medicine, Key Laboratory of Clinical Laboratory Diagnostics in Universities of Shandong, Weifang Medical University, Weifang, Shandong, China
| | - Yuqin Song
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaolei Pan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Un-Hwan Ha
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea
| | - Jie Feng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology (SUSTec), Shenzhen, China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Fang Bai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
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Braun V, Hartmann MD, Hantke K. Transcription regulation of iron carrier transport genes by ECF sigma factors through signaling from the cell surface into the cytoplasm. FEMS Microbiol Rev 2022; 46:6524835. [PMID: 35138377 PMCID: PMC9249621 DOI: 10.1093/femsre/fuac010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 01/26/2022] [Accepted: 02/07/2022] [Indexed: 12/02/2022] Open
Abstract
Bacteria are usually iron-deficient because the Fe3+ in their environment is insoluble or is incorporated into proteins. To overcome their natural iron limitation, bacteria have developed sophisticated iron transport and regulation systems. In gram-negative bacteria, these include iron carriers, such as citrate, siderophores, and heme, which when loaded with Fe3+ adsorb with high specificity and affinity to outer membrane proteins. Binding of the iron carriers to the cell surface elicits a signal that initiates transcription of iron carrier transport and synthesis genes, referred to as “cell surface signaling”. Transcriptional regulation is not coupled to transport. Outer membrane proteins with signaling functions contain an additional N-terminal domain that in the periplasm makes contact with an anti-sigma factor regulatory protein that extends from the outer membrane into the cytoplasm. Binding of the iron carriers to the outer membrane receptors elicits proteolysis of the anti-sigma factor by two different proteases, Prc in the periplasm, and RseP in the cytoplasmic membrane, inactivates the anti-sigma function or results in the generation of an N-terminal peptide of ∼50 residues with pro-sigma activity yielding an active extracytoplasmic function (ECF) sigma factor. Signal recognition and signal transmission into the cytoplasm is discussed herein.
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Affiliation(s)
- Volkmar Braun
- Max Planck Institute for Biology, Department of Protein Evolution, Max Planck Ring 5, 72076 Tübingen, Germany
| | - Marcus D Hartmann
- Max Planck Institute for Biology, Department of Protein Evolution, Max Planck Ring 5, 72076 Tübingen, Germany
| | - Klaus Hantke
- IMIT Institute, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
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Butt AT, Banyard CD, Haldipurkar SS, Agnoli K, Mohsin M, Vitovski S, Paleja A, Tang Y, Lomax R, Ye F, Green J, Thomas M. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3709-3726. [PMID: 35234897 PMCID: PMC9023288 DOI: 10.1093/nar/gkac137] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/28/2022] [Accepted: 02/14/2022] [Indexed: 11/14/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen that causes severe infections of the cystic fibrosis (CF) lung. To acquire iron, B. cenocepacia secretes the Fe(III)-binding compound, ornibactin. Genes for synthesis and utilisation of ornibactin are served by the iron starvation (IS) extracytoplasmic function (ECF) σ factor, OrbS. Transcription of orbS is regulated in response to the prevailing iron concentration by the ferric uptake regulator (Fur), such that orbS expression is repressed under iron-sufficient conditions. Here we show that, in addition to Fur-mediated regulation of orbS, the OrbS protein itself responds to intracellular iron availability. Substitution of cysteine residues in the C-terminal region of OrbS diminished the ability to respond to Fe(II) in vivo. Accordingly, whilst Fe(II) impaired transcription from and recognition of OrbS-dependent promoters in vitro by inhibiting the binding of OrbS to core RNA polymerase (RNAP), the cysteine-substituted OrbS variant was less responsive to Fe(II). Thus, the cysteine residues within the C-terminal region of OrbS contribute to an iron-sensing motif that serves as an on-board ‘anti-σ factor’ in the presence of Fe(II). A model to account for the presence two regulators (Fur and OrbS) that respond to the same intracellular Fe(II) signal to control ornibactin synthesis and utilisation is discussed.
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Affiliation(s)
- Aaron T Butt
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Christopher D Banyard
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Sayali S Haldipurkar
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Kirsty Agnoli
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Muslim I Mohsin
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Srdjan Vitovski
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Ameya Paleja
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Yingzhi Tang
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Rebecca Lomax
- Department of Infection, Immunity and Cardiovascular Disease, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield S10 2RX, UK
| | - Fuzhou Ye
- Section of Structural Biology, Department of Infectious Disease, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK
| | - Jeffrey Green
- Correspondence may also be addressed to Jeffrey Green. Tel: +44 114 222 4403; Fax: +44 114 222 2800;
| | - Mark S Thomas
- To whom correspondence should be addressed. Tel: +44 114 215 9557; Fax: +44 114 271 1863;
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Iron Homeostasis in Pseudomonas aeruginosa: Targeting Iron Acquisition and Storage as an Antimicrobial Strategy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:29-68. [DOI: 10.1007/978-3-031-08491-1_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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42
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Extracellular haem utilization by the opportunistic pathogen Pseudomonas aeruginosa and its role in virulence and pathogenesis. Adv Microb Physiol 2021; 79:89-132. [PMID: 34836613 DOI: 10.1016/bs.ampbs.2021.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Iron is an essential micronutrient for all bacteria but presents a significant challenge given its limited bioavailability. Furthermore, iron's toxicity combined with the need to maintain iron levels within a narrow physiological range requires integrated systems to sense, regulate and transport a variety of iron complexes. Most bacteria encode systems to chelate and transport ferric iron (Fe3+) via siderophore receptor mediated uptake or via cytoplasmic energy dependent transport systems. Pathogenic bacteria have further lowered the barrier to iron acquisition by employing systems to utilize haem as a source of iron. Haem, a lipophilic and toxic molecule, presents a significant challenge for transport into the cell. As such pathogenic bacteria have evolved sophisticated cell surface signaling (CSS) and transport systems to sense and obtain haem from the host. Once internalized haem is cleaved by both oxidative and non-oxidative mechanisms to release iron. Herein we summarize our current understanding of the mechanism of haem sensing, uptake and utilization in Pseudomonas aeruginosa, its role in pathogenesis and virulence, and the potential of these systems as antimicrobial targets.
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Fernández-Gómez P, Figueredo A, López M, González-Raurich M, Prieto M, Alvarez-Ordóñez A. Heterogeneity in biofilm formation and identification of biomarkers of strong biofilm formation among field isolates of Pseudomonas spp. Food Res Int 2021; 148:110618. [PMID: 34507762 DOI: 10.1016/j.foodres.2021.110618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 10/20/2022]
Abstract
The biofilm formation ability of a collection of thirty-three Pseudomonas spp. isolates from food processing facilities was investigated in order to find biomarkers of strong biofilm production, a characteristic that can determine persistence in food processing environments. The strains were classified according to the colony pigmentation on solid media as green, brown or not pigmented. The biofilm production on stainless steel and polystyrene was assessed by spectrometric determination of the fixed crystal violet, and the biofilm formed on glass, through confocal laser scanning microscopy. Besides, pyoverdine production, catalase activity, RpoS status and cellular hydrophobicity were also monitored. A significantly higher biofilm production level on stainless steel and polystyrene was observed for green-pigmented strains as compared to brown or not pigmented strains. The influence of iron availability on biofilm formation on stainless steel was studied through the addition of the iron scavenger 2,2-bipyridine resulting in a decrease of 40 % in biofilm formation for the not pigmented strains. For most of the potential biomarkers studied (i.e., pyoverdine production, catalase activity, cellular hydrophobicity), the phenotypic heterogeneity observed among strains was mainly dependent on the Pseudomonas species and no strong associations with the biofilm formation capacity were detected. However, the green colony pigmentation on solid media showed good potential as a biomarker of strong biofilm formation on stainless steel and polystyrene both in P. aeruginosa and Pseudomonas spp.
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Affiliation(s)
| | | | - Mercedes López
- Department of Food Hygiene and Technology, Universidad de León, León, Spain; Institute of Food Science and Technology, Universidad de León, León, Spain
| | - Montserrat González-Raurich
- Department of Food Hygiene and Technology, Universidad de León, León, Spain; Institute of Food Science and Technology, Universidad de León, León, Spain
| | - Miguel Prieto
- Department of Food Hygiene and Technology, Universidad de León, León, Spain; Institute of Food Science and Technology, Universidad de León, León, Spain
| | - Avelino Alvarez-Ordóñez
- Department of Food Hygiene and Technology, Universidad de León, León, Spain; Institute of Food Science and Technology, Universidad de León, León, Spain.
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Dent AT, Brimberry M, Albert T, Lanzilotta WN, Moënne-Loccoz P, Wilks A. Axial Heme Coordination by the Tyr-His Motif in the Extracellular Hemophore HasAp Is Critical for the Release of Heme to the HasR Receptor of Pseudomonas aeruginosa. Biochemistry 2021; 60:2549-2559. [PMID: 34324310 DOI: 10.1021/acs.biochem.1c00389] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pseudomonas aeruginosa senses extracellular heme via an extra cytoplasmic function σ factor that is activated upon interaction of the hemophore holo-HasAp with the HasR receptor. Herein, we show Y75H holo-HasAp interacts with HasR but is unable to release heme for signaling and uptake. To understand this inhibition, we undertook a spectroscopic characterization of Y75H holo-HasAp by resonance Raman (RR), electron paramagnetic resonance (EPR), and X-ray crystallography. The RR spectra are consistent with a mixed six-coordinate high-spin (6cHS), six-coordinate low-spin (6cLS) heme configuration and an H218O exchangeable FeIII-O stretching frequency with 16O/18O and H/D isotope shifts that support a two-body Fe-OH2 oscillator with (iron-hydroxy)-like character as both hydrogen atoms are engaged in short hydrogen bond interactions with protein side chains. Further support comes from the EPR spectrum of Y75H holo-HasAp that shows a LS rhombic signal with ligand-field splitting values intermediate between those of His-hydroxy and bis-His ferric hemes. The crystal structure of Y75H holo-HasAp confirmed the coordinated solvent molecule hydrogen bonded through H75 and H83. The long-range conformational rearrangement of HasAp upon heme binding can still take place in Y75H holo-HasAp, because the intercalation of a hydroxy ligand between the heme iron and H75 allows the variant to reproduce the heme binding pocket observed in wild-type holo-HasAp. However, in the absence of a covalent linkage to the Y75 loop combined with the malleability provided by the bracketing H75 and H83 hydrogen bonds, either the hydroxy sixth ligand remains bound after complexation of Y75H holo-HasAp with HasR or rearrangement and coordination of H85 prevent heme transfer.
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Affiliation(s)
- Alecia T Dent
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201, United States
| | - Marley Brimberry
- Department of Biochemistry and Molecular Biology, Franklin College of Arts and Sciences, University of Georgia, Athens, Georgia 30602, United States
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - William N Lanzilotta
- Department of Biochemistry and Molecular Biology, Franklin College of Arts and Sciences, University of Georgia, Athens, Georgia 30602, United States
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Angela Wilks
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201, United States
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45
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Li C, Pan D, Li M, Wang Y, Song L, Yu D, Zuo Y, Wang K, Liu Y, Wei Z, Lu Z, Zhu L, Shen X. Aerobactin-Mediated Iron Acquisition Enhances Biofilm Formation, Oxidative Stress Resistance, and Virulence of Yersinia pseudotuberculosis. Front Microbiol 2021; 12:699913. [PMID: 34335534 PMCID: PMC8319957 DOI: 10.3389/fmicb.2021.699913] [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: 04/24/2021] [Accepted: 06/09/2021] [Indexed: 11/13/2022] Open
Abstract
Aerobactin is a citrate-hydroxamate siderophore that is critical for the virulence of pathogenic enteric bacteria. However, although the aerobactin-producing iucABCD-iutA operon is distributed widely in the genomes of Yersinia species, none of the pathogenic Yersinia spp. was found to produce aerobactin. Here, we showed that the iucABCD-iutA operon in the food-borne enteric pathogen Yersinia pseudotuberculosis YPIII is a functional siderophore system involved in iron acquisition. The expression of the operon was found to be directly repressed by the ferric uptake regulator (Fur) in an iron concentration-dependent manner. In addition, we demonstrated that the aerobactin-mediated iron acquisition contributes to bacterial growth under iron-limited conditions. Moreover, we provided evidence that aerobactin plays important roles in biofilm formation, resistance to oxidative stress, ROS removal, and virulence of Y. pseudotuberculosis. Overall, our study not only uncovered a novel strategy of iron acquisition in Y. pseudotuberculosis but also highlighted the importance of aerobactin in the pathogenesis of Y. pseudotuberculosis.
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Affiliation(s)
- Changfu Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China.,Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Damin Pan
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Mengyuan Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Luting Song
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Danyang Yu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Yuxin Zuo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Kenan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Yuqi Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China.,Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Zhiyan Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Zhiqiang Lu
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Lingfang Zhu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China.,Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
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46
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Ma N, Sun C. Cadmium sulfide nanoparticle biomineralization and biofilm formation mediate cadmium resistance of the deep-sea bacterium Pseudoalteromonas sp. MT33b. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:325-336. [PMID: 33511774 DOI: 10.1111/1758-2229.12933] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 06/12/2023]
Abstract
Cadmium (Cd) is a common toxic heavy metal in the environment, and bacteria have evolved different strategies to deal with Cd toxicity. Here, a bacterium designated Pseudoalteromonas sp. MT33b possessing strong Cd resistance was isolated from the Mariana Trench sediments. Supplement of cysteine significantly increased bacterial Cd resistance and removal rate. Biofilm formation was demonstrated to play a positive role toward bacterial Cd resistance. Transcriptome analysis showed the supplement of cysteine effectively prevented Cd2+ from entering bacterial cells, promoted saccharide metabolism and thereby facilitating energy production, which consists well with bacterial growth trend analysed under the same conditions. Notably, the expressions of many biofilm formation related genes including flagellar assembly, signal transduction, bacterial secretion and TonB-dependent transfer system were significantly upregulated when facing Cd stress, indicating their important roles in determining bacterial biofilm formation and enhancing Cd resistance. Overall, this study indicates the formation of insoluble CdS precipitates and massive biofilm is the major strategy adopted by Pseudoalteromonas sp. MT33b to eliminate Cd stress. Our results provide a good model to investigate how heavy metals impact biofilm formation in the deep-sea ecosystems, which may facilitate a deeper understanding of microbial environmental adaptability and better utilization of these microbes for bioremediation purposes in the future.
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Affiliation(s)
- Ning Ma
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing, 100049, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Chaomin Sun
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
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47
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Klebba PE, Newton SMC, Six DA, Kumar A, Yang T, Nairn BL, Munger C, Chakravorty S. Iron Acquisition Systems of Gram-negative Bacterial Pathogens Define TonB-Dependent Pathways to Novel Antibiotics. Chem Rev 2021; 121:5193-5239. [PMID: 33724814 PMCID: PMC8687107 DOI: 10.1021/acs.chemrev.0c01005] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron is an indispensable metabolic cofactor in both pro- and eukaryotes, which engenders a natural competition for the metal between bacterial pathogens and their human or animal hosts. Bacteria secrete siderophores that extract Fe3+ from tissues, fluids, cells, and proteins; the ligand gated porins of the Gram-negative bacterial outer membrane actively acquire the resulting ferric siderophores, as well as other iron-containing molecules like heme. Conversely, eukaryotic hosts combat bacterial iron scavenging by sequestering Fe3+ in binding proteins and ferritin. The variety of iron uptake systems in Gram-negative bacterial pathogens illustrates a range of chemical and biochemical mechanisms that facilitate microbial pathogenesis. This document attempts to summarize and understand these processes, to guide discovery of immunological or chemical interventions that may thwart infectious disease.
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Affiliation(s)
- Phillip E Klebba
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Salete M C Newton
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - David A Six
- Venatorx Pharmaceuticals, Inc., 30 Spring Mill Drive, Malvern, Pennsylvania 19355, United States
| | - Ashish Kumar
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Taihao Yang
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Brittany L Nairn
- Department of Biological Sciences, Bethel University, 3900 Bethel Drive, St. Paul, Minnesota 55112, United States
| | - Colton Munger
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Somnath Chakravorty
- Jacobs School of Medicine and Biomedical Sciences, SUNY Buffalo, Buffalo, New York 14203, United States
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48
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Generation of Genetic Tools for Gauging Multiple-Gene Expression at the Single-Cell Level. Appl Environ Microbiol 2021; 87:AEM.02956-20. [PMID: 33608300 DOI: 10.1128/aem.02956-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/11/2021] [Indexed: 11/20/2022] Open
Abstract
Key microbial processes in many bacterial species are heterogeneously expressed in single cells of bacterial populations. However, the paucity of adequate molecular tools for live, real-time monitoring of multiple-gene expression at the single-cell level has limited the understanding of phenotypic heterogeneity. To investigate phenotypic heterogeneity in the ubiquitous opportunistic pathogen Pseudomonas aeruginosa, a genetic tool that allows gauging multiple-gene expression at the single-cell level has been generated. This tool, named pRGC, consists of a promoter-probe vector for transcriptional fusions that carries three reporter genes coding for the fluorescent proteins mCherry, green fluorescent protein (GFP), and cyan fluorescent protein (CFP). The pRGC vector has been characterized and validated via single-cell gene expression analysis of both constitutive and iron-regulated promoters, showing clear discrimination of the three fluorescence signals in single cells of a P. aeruginosa population without the need for image processing for spectral cross talk correction. In addition, two pRGC variants have been generated for either (i) integration of the reporter gene cassette into a single neutral site of P. aeruginosa chromosome that is suitable for long-term experiments in the absence of antibiotic selection or (ii) replication in bacterial genera other than Pseudomonas The easy-to-use genetic tools generated in this study will allow rapid and cost-effective investigation of multiple-gene expression in populations of environmental and pathogenic bacteria, hopefully advancing the understanding of microbial phenotypic heterogeneity.IMPORTANCE Within a bacterial population, single cells can differently express some genes, even though they are genetically identical and experience the same chemical and physical stimuli. This phenomenon, known as phenotypic heterogeneity, is mainly driven by gene expression noise and results in the emergence of bacterial subpopulations with distinct phenotypes. The analysis of gene expression at the single-cell level has shown that phenotypic heterogeneity is associated with key bacterial processes, including competence, sporulation, and persistence. In this study, new genetic tools have been generated that allow easy cloning of up to three promoters upstream of distinct fluorescent genes, making it possible to gauge multiple-gene expression at the single-cell level by fluorescence microscopy without the need for advanced image-processing procedures. A proof of concept has been provided by investigating iron uptake and iron storage gene expression in response to iron availability in P. aeruginosa.
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49
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Bradley JM, Svistunenko DA, Wilson MT, Hemmings AM, Moore GR, Le Brun NE. Bacterial iron detoxification at the molecular level. J Biol Chem 2021; 295:17602-17623. [PMID: 33454001 PMCID: PMC7762939 DOI: 10.1074/jbc.rev120.007746] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 10/07/2020] [Indexed: 01/18/2023] Open
Abstract
Iron is an essential micronutrient, and, in the case of bacteria, its availability is commonly a growth-limiting factor. However, correct functioning of cells requires that the labile pool of chelatable "free" iron be tightly regulated. Correct metalation of proteins requiring iron as a cofactor demands that such a readily accessible source of iron exist, but overaccumulation results in an oxidative burden that, if unchecked, would lead to cell death. The toxicity of iron stems from its potential to catalyze formation of reactive oxygen species that, in addition to causing damage to biological molecules, can also lead to the formation of reactive nitrogen species. To avoid iron-mediated oxidative stress, bacteria utilize iron-dependent global regulators to sense the iron status of the cell and regulate the expression of proteins involved in the acquisition, storage, and efflux of iron accordingly. Here, we survey the current understanding of the structure and mechanism of the important members of each of these classes of protein. Diversity in the details of iron homeostasis mechanisms reflect the differing nutritional stresses resulting from the wide variety of ecological niches that bacteria inhabit. However, in this review, we seek to highlight the similarities of iron homeostasis between different bacteria, while acknowledging important variations. In this way, we hope to illustrate how bacteria have evolved common approaches to overcome the dual problems of the insolubility and potential toxicity of iron.
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Affiliation(s)
- Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
| | | | - Michael T Wilson
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Andrew M Hemmings
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom; Centre for Molecular and Structural Biochemistry, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Geoffrey R Moore
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
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50
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Brandenburg KS, Weaver AJ, Karna SLR, Leung KP. The impact of simultaneous inoculation of Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans on rodent burn wounds. Burns 2021; 47:1818-1832. [PMID: 33771422 DOI: 10.1016/j.burns.2021.02.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/13/2021] [Accepted: 02/18/2021] [Indexed: 12/27/2022]
Abstract
Burn wound infection often involves a diverse combination of bacterial and fungal pathogens. In this study, we characterize the mixed species burn wound infection by inoculating the burn surface with 1 × 103/4/5 CFU of Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans in a 1:1:1 ratio. Using the revised Walker-Mason scald burn rat model, 168 male Sprague-Dawley rats (350-450 g) subject to ∼10% TBSA burn injury, with or without inoculation, were evaluated for 11 days after burn. In the wound, P. aeruginosa and S. aureus formed robust biofilms as determined by the bacterial tissue load, ∼1 × 109 CFU/g, and expression of key biofilm genes. Interestingly, within 3 days C. albicans achieved tissue loads of ∼1 × 106 CFU/g, but its numbers were significantly reduced beyond the limit of detection in the burn wound by day 7 in partial-thickness injuries and by day 11 in full-thickness injuries. The pathogenic biofilms contributed to burn depth progression, increased release of HMGB-1 into circulation from injured tissue, and significantly elevated the numbers of circulating innate immune cells (Neutrophils, Monocytes, and Basophils). This robust model of multi-species burn wound infection will serve as the basis for the development of new antimicrobials for combating biofilm-based wound infections.
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Affiliation(s)
- Kenneth S Brandenburg
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
| | - Alan J Weaver
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
| | - S L Rajasekhar Karna
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
| | - Kai P Leung
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
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