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Paul Ikujuni A, Dhar R, Cordova A, Bowman AM, Noga S, Slusky JSG. Discovery and Characterization of Two Folded Intermediates for Outer Membrane Protein TolC Biogenesis. J Mol Biol 2024:168652. [PMID: 38871177 DOI: 10.1016/j.jmb.2024.168652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 05/12/2024] [Accepted: 06/06/2024] [Indexed: 06/15/2024]
Abstract
TolC is the outer membrane protein responsible for antibiotic efflux in E. coli. Compared to other outer membrane proteins it has an unusual fold and has been shown to fold independently of commonly used periplasmic chaperones, SurA and Skp. Here we find that the assembly of TolC involves the formation of two folded intermediates using circular dichroism, gel electrophoresis, site-specific disulfide bond formation and radioactive labeling. First the TolC monomer folds, and then TolC assembles into a trimer both in detergent-free buffer and in the presence of detergent micelles. We find that a TolC trimer also forms in the periplasm and is present in the periplasm before it inserts in the outer membrane. The monomeric and trimeric folding intermediates may be used in the future to develop a new approach to antibiotic efflux pump inhibition by targeting the assembly pathway of TolC.
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Affiliation(s)
- Ayotunde Paul Ikujuni
- Department of Molecular Biosciences, The University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045
| | - Rik Dhar
- Department of Molecular Biosciences, The University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045
| | - Andres Cordova
- Department of Molecular Biosciences, The University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045
| | - Alexander M Bowman
- Department of Molecular Biosciences, The University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045
| | - Sarah Noga
- Department of Molecular Biosciences, The University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045
| | - Joanna S G Slusky
- Department of Molecular Biosciences, The University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045; Computational Biology Program, The University of Kansas, 2030 Becker Dr., Lawrence, KS 66045-7534.
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2
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Barco RA, Merino N, Lam B, Budnik B, Kaplan M, Wu F, Amend JP, Nealson KH, Emerson D. Comparative proteomics of a versatile, marine, iron-oxidizing chemolithoautotroph. Environ Microbiol 2024; 26:e16632. [PMID: 38861374 DOI: 10.1111/1462-2920.16632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/20/2024] [Indexed: 06/13/2024]
Abstract
This study conducted a comparative proteomic analysis to identify potential genetic markers for the biological function of chemolithoautotrophic iron oxidation in the marine bacterium Ghiorsea bivora. To date, this is the only characterized species in the class Zetaproteobacteria that is not an obligate iron-oxidizer, providing a unique opportunity to investigate differential protein expression to identify key genes involved in iron-oxidation at circumneutral pH. Over 1000 proteins were identified under both iron- and hydrogen-oxidizing conditions, with differentially expressed proteins found in both treatments. Notably, a gene cluster upregulated during iron oxidation was identified. This cluster contains genes encoding for cytochromes that share sequence similarity with the known iron-oxidase, Cyc2. Interestingly, these cytochromes, conserved in both Bacteria and Archaea, do not exhibit the typical β-barrel structure of Cyc2. This cluster potentially encodes a biological nanowire-like transmembrane complex containing multiple redox proteins spanning the inner membrane, periplasm, outer membrane, and extracellular space. The upregulation of key genes associated with this complex during iron-oxidizing conditions was confirmed by quantitative reverse transcription-PCR. These findings were further supported by electromicrobiological methods, which demonstrated negative current production by G. bivora in a three-electrode system poised at a cathodic potential. This research provides significant insights into the biological function of chemolithoautotrophic iron oxidation.
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Affiliation(s)
- Roman A Barco
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, USA
| | - N Merino
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Lawrence Livermore National Lab, Biosciences and Biotechnology Division, Livermore, California, USA
| | - B Lam
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - B Budnik
- Mass Spectrometry and Proteomics Resource Laboratory, Harvard University, Cambridge, Massachusetts, USA
| | - M Kaplan
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - F Wu
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, Zhejiang, China
| | - J P Amend
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - K H Nealson
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - D Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, USA
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3
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Laborda P, Molin S, Johansen HK, Martínez JL, Hernando-Amado S. Role of bacterial multidrug efflux pumps during infection. World J Microbiol Biotechnol 2024; 40:226. [PMID: 38822187 DOI: 10.1007/s11274-024-04042-7] [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: 04/03/2024] [Accepted: 05/29/2024] [Indexed: 06/02/2024]
Abstract
Multidrug efflux pumps are protein complexes located in the cell envelope that enable bacteria to expel, not only antibiotics, but also a wide array of molecules relevant for infection. Hence, they are important players in microbial pathogenesis. On the one hand, efflux pumps can extrude exogenous compounds, including host-produced antimicrobial molecules. Through this extrusion, pathogens can resist antimicrobial agents and evade host defenses. On the other hand, efflux pumps also have a role in the extrusion of endogenous compounds, such as bacterial intercommunication signaling molecules, virulence factors or metabolites. Therefore, efflux pumps are involved in the modulation of bacterial behavior and virulence, as well as in the maintenance of the bacterial homeostasis under different stresses found within the host. This review delves into the multifaceted roles that efflux pumps have, shedding light on their impact on bacterial virulence and their contribution to bacterial infection. These observations suggest that strategies targeting bacterial efflux pumps could both reinvigorate the efficacy of existing antibiotics and modulate the bacterial pathogenicity to the host. Thus, a comprehensive understanding of bacterial efflux pumps can be pivotal for the development of new effective strategies for the management of infectious diseases.
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Affiliation(s)
- Pablo Laborda
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, 9301, Denmark.
| | - Søren Molin
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, 9301, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Zhu S, Alexander MK, Paiva TO, Rachwalski K, Miu A, Xu Y, Verma V, Reichelt M, Dufrêne YF, Brown ED, Cox G. The inactivation of tolC sensitizes Escherichia coli to perturbations in lipopolysaccharide transport. iScience 2024; 27:109592. [PMID: 38628966 PMCID: PMC11019271 DOI: 10.1016/j.isci.2024.109592] [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: 12/01/2023] [Revised: 02/02/2024] [Accepted: 03/25/2024] [Indexed: 04/19/2024] Open
Abstract
The Escherichia coli outer membrane channel TolC complexes with several inner membrane efflux pumps to export compounds across the cell envelope. All components of these complexes are essential for robust efflux activity, yet E. coli is more sensitive to antimicrobial compounds when tolC is inactivated compared to the inactivation of genes encoding the inner membrane drug efflux pumps. While investigating these susceptibility differences, we identified a distinct class of inhibitors targeting the core-lipopolysaccharide translocase, MsbA. We show that tolC null mutants are sensitized to structurally unrelated MsbA inhibitors and msbA knockdown, highlighting a synthetic-sick interaction. Phenotypic profiling revealed that tolC inactivation induced cell envelope softening and increased outer membrane permeability. Overall, this work identified a chemical probe of MsbA, revealed that tolC is associated with cell envelope mechanics and integrity, and highlighted that these findings should be considered when using tolC null mutants to study efflux deficiency.
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Affiliation(s)
- Shawna Zhu
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E, Guelph, ON N1G 2W1, Canada
| | | | - Telmo O. Paiva
- Institute of Life Sciences, UCLouvain, Croix du Sud, 4-5, bte L7.07.06, B-1348 Louvain-la-Neuve, Belgium
| | - Kenneth Rachwalski
- Biochemistry and Biomedical Sciences and Degroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Anh Miu
- Genentech Inc, Biochemical and Cellular Pharmacology, South San Francisco, CA, USA
| | - Yiming Xu
- Genentech Inc, Infectious Diseases, South San Francisco, CA, USA
| | - Vishal Verma
- Genentech Inc, Discovery Chemistry, South San Francisco, CA, USA
| | - Mike Reichelt
- Genentech Inc, Pathology, South San Francisco, CA, USA
| | - Yves F. Dufrêne
- Institute of Life Sciences, UCLouvain, Croix du Sud, 4-5, bte L7.07.06, B-1348 Louvain-la-Neuve, Belgium
| | - Eric D. Brown
- Biochemistry and Biomedical Sciences and Degroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Georgina Cox
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E, Guelph, ON N1G 2W1, Canada
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Khazaal MT, Faraag AHI, El-Hendawy HH. In vitro and in silico studies of enterobactin-inspired Ciprofloxacin and Fosfomycin first generation conjugates on the antibiotic resistant E. coli OQ866153. BMC Microbiol 2024; 24:95. [PMID: 38519885 PMCID: PMC10958948 DOI: 10.1186/s12866-024-03248-x] [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: 08/27/2023] [Accepted: 03/03/2024] [Indexed: 03/25/2024] Open
Abstract
BACKGROUND The emergence of antimicrobial resistance in bacterial pathogens is a growing concern worldwide due to its impact on the treatment of bacterial infections. The "Trojan Horse" strategy has been proposed as a potential solution to overcome drug resistance caused by permeability issues. OBJECTIVE The objective of our research was to investigate the bactericidal activity and mechanism of action of the "Trojan Horse" strategy using enterobactin conjugated with Ciprofloxacin and Fosfomycin against the antibiotic-resistant Escherichia coli strain OQ866153. METHODOLOGY Enterobactin, a mixed ligand of E. coli OQ866153, was conjugated with Ciprofloxacin and Fosfomycin individually to aid active absorption via specific enterobactin binding proteins (FepABCDG). The effectiveness of the conjugates was assessed by measuring their bactericidal activity against E. coli OQ866153, as well as their ability to inhibit DNA gyrase enzyme and biofilm formation. RESULTS The Fe+3-enterobactin-Ciprofloxacin conjugate effectively inhibited the DNA gyrase enzyme (Docking score = -8.597 kcal/mol) and resulted in a lower concentration (25 μg/ml) required to eliminate supercoiled DNA plasmids compared to the parent drug (35 μg/ml; Docking score = -6.264 kcal/mol). The Fe+3-Enterobactin-Fosfomycin conjugate showed a higher inhibition percentage (100%) of biofilm formation compared to Fosfomycin (21.58%) at a concentration of 2 mg/ml, with docking scores of -5.481 and -3.756 kcal/mol against UDP-N acetylglucosamine 1-carboxyvinyltransferase MurA. CONCLUSION The findings of this study suggest that the "Trojan Horse" strategy using enterobactin conjugated with Ciprofloxacin and Fosfomycin can effectively overcome permeability issues caused by efflux proteins and enhance the bactericidal activity of these drugs against antibiotic-resistant strains of E. coli.
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Affiliation(s)
- Mohamed T Khazaal
- Botany and Microbiology Department, Faculty of Science, Helwan University, HelwanCairo, 11795, Egypt
| | - Ahmed H I Faraag
- Botany and Microbiology Department, Faculty of Science, Helwan University, HelwanCairo, 11795, Egypt.
- School of Biotechnology, Badr University in Cairo, Badr City, Cairo, 11829, Egypt.
| | - Hoda H El-Hendawy
- Botany and Microbiology Department, Faculty of Science, Helwan University, HelwanCairo, 11795, Egypt.
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Chen J, Zhang X, Kuang M, Cui K, Xu T, Liu X, Zhuo R, Qin Z, Bu Z, Huang Z, Li H, Huang J, Liu T, Zhu Y. Endophytic Enterobacter sp. YG-14 mediated arsenic mobilization through siderophore and its role in enhancing phytostabilization. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133206. [PMID: 38134692 DOI: 10.1016/j.jhazmat.2023.133206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/26/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023]
Abstract
Soil arsenic (As) phytoremediation has long faced the challenge of efficiently absorbing As by plant accumulators while maintaining their health and fast growth. Even at low doses, arsenic is highly toxic to plants. Therefore, plant growth-promoting microorganisms that can mediate As accumulation in plants are of great interest. In this study, the endophyte Enterobacter sp. YG-14 (YG-14) was found to have soil mobilization activity. By constructing a siderophore synthesis gene deletion mutant (ΔentD) of YG-14, the endophyte was confirmed to effectively mobilize Fe-As complexes in mining soil by secreting enterobactin, releasing bioavailable Fe and As to the rhizosphere. YG-14 also enhances As accumulation in host plants via extracellular polymer adsorption and specific phosphatase transfer protein (PitA) absorption. The root accumulation of As was positively correlated with YG-14 root colonization. In addition, YG-14 promoted plant growth and alleviated oxidative damage in R. pseudoacacia L. under arsenic stress. This is the first study, from phenotype, physiology, and molecular perspectives, to determine the role of endophyte in promoting As phytostabilization and maintaining the growth of the host plant. This demonstrated the feasibility of using endophytes with high siderophore production to assist host plants in As phytoremediation.
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Affiliation(s)
- Jiawei Chen
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Xuan Zhang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, PR China
| | - Min Kuang
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Kunpeng Cui
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Ting Xu
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Xuanming Liu
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Rui Zhuo
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Ziwei Qin
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Zhigang Bu
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China
| | - Zhongliang Huang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, PR China
| | - Hui Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, PR China
| | - Jing Huang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, PR China
| | - Tingting Liu
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, PR China
| | - Yonghua Zhu
- Hunan Provincial Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, Hunan, PR China.
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Miyamoto K. [New Drug Discovery Targeting Iron in Bacterial Infectious Diseases]. YAKUGAKU ZASSHI 2024; 144:633-641. [PMID: 38825472 DOI: 10.1248/yakushi.23-00197-2] [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: 06/04/2024]
Abstract
Iron is necessary for all living organisms, and bacteria that cause infections in human hosts also need ferrous ions for their growth and proliferation. In the human body, most ferric ions (Fe3+) are tightly bound to iron-binding proteins such as hemoglobin, transferrin, lactoferrin, and ferritin. Pathogenic bacteria express highly specific iron uptake systems, including siderophores and specific receptors. Most bacteria secrete siderophores, which are low-molecular weight metal-chelating agents, to capture Fe3+ outside cell. Siderophores are mainly classified as either catecholate or hydroxamate. Vibrio vulnificus, a Gram-negative pathogenic bacterium, is responsible for serious infections in humans and requires iron for growth. A clinical isolate, V. vulnificus M2799, secretes a catecholate siderophore, vulnibactin, that captures ferric ions from the environment. In our study, we generated deletion mutants of the genes encoding proteins involved in the vulnibactin mediated iron-utilization system, such as ferric-vulnibactin receptor protein (VuuA), periplasmic ferric-vulnibactin binding protein (FatB), ferric-vulnibactin reductase (VuuB), and isochorismate synthase (ICS). ICS and VuuA are required under low-iron conditions for ferric-utilization in M2799, but the alternative proteins FatB and VuuB can function as a periplasmic binding protein and a ferric-chelate reductase, respectively. VatD, which functions as ferric-hydroxamate siderophores periplasmic binding protein, was shown to participate in the ferric-vulnibactin uptake system in the absence of FatB. Furthermore, the ferric-hydroxamate siderophore reductase IutB was observed to participate in ferric-vulnibactin reduction in the absence of VuuB. We propose that ferric-siderophore periplasmic binding proteins and ferric-chelate reductases represent potential targets for drug discovery in the context of infectious diseases.
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Affiliation(s)
- Katsushiro Miyamoto
- Department of Microbiology and Infection Control, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University
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Huang L, Guo F, Li X, Wang M, Zhu D, Wang M, Jia R, Chen S, Zhao X, Zhang S, Gao Q, Yang Q, Wu Y, Huang J, Tian B, Ou X, Sun D, Mao S, Zhang L, Yu Y, Götz F, Cheng A, Liu M. Functional characterization of two TolC in the resistance to drugs and metals and in the virulence of Riemerella anatipestifer. Appl Environ Microbiol 2023; 89:e0130823. [PMID: 38038982 PMCID: PMC10734528 DOI: 10.1128/aem.01308-23] [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: 07/29/2023] [Accepted: 10/18/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE Riemerella anatipestifer (RA) is a notorious duck pathogen, characterized by a multitude of serotypes that exhibit no cross-reaction with one another. Moreover, RA is resistant to various antibacterial agents. Consequently, understanding the mechanisms behind resistance and identifying potential targets for drug development have become pressing needs. In this study, we show that the two TolC proteins play a role in the resistance to different drugs and metals and in the virulence. The results suggest that TolCA has a wider range of efflux substrates than TolCB. Except for gentamicin, neither TolCA nor TolCB was involved in the efflux of the other tested antibiotics. Strikingly, TolCA but not TolCB enhanced the frequency of resistance-conferring mutations. Moreover, TolCA was involved in RA virulence. Given its conservation in RA, TolCA has potential as a drug target for the development of therapeutics against RA infections.
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Affiliation(s)
- Li Huang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- College of Animal Husbandry and Veterinary Medicine, Southwest Minzu University, Chengdu, China
| | - Fang Guo
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiao Li
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mengying Wang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dekang Zhu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shun Chen
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinxin Zhao
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shaqiu Zhang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qun Gao
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qiao Yang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ying Wu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Juan Huang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Bin Tian
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xumin Ou
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Di Sun
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Sai Mao
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - YanLing Yu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Friedrich Götz
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Anchun Cheng
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mafeng Liu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
- International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
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9
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Bina XR, Weng Y, Budnick J, Van Allen ME, Bina JE. Klebsiella pneumoniae TolC contributes to antimicrobial resistance, exopolysaccharide production, and virulence. Infect Immun 2023; 91:e0030323. [PMID: 37982617 PMCID: PMC10715176 DOI: 10.1128/iai.00303-23] [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: 08/04/2023] [Accepted: 10/26/2023] [Indexed: 11/21/2023] Open
Abstract
Klebsiella pneumoniae is a Gram-negative bacterium that causes a variety of human diseases, ranging from pneumonia to urinary tract infections and invasive diseases. The emergence of K. pneumoniae strains that are resistant to multiple antibiotics has made treatment more complex and led to K. pneumoniae becoming a global health threat. Addressing this threat necessitates the development of new therapeutic strategies to combat this pathogen, including strategies to overcome antimicrobial resistance and therapeutics for novel targets such as antivirulence. Here, we investigated the function of TolC, an outer membrane protein essential for the function of tripartite transporters, in K. pneumoniae. Mutation of tolC rendered K. pneumoniae hypersensitive to multiple antibiotics. Moreover, the tolC mutation impaired capsule production and affected the expression of key capsule biosynthetic genes, indicating a regulatory role for TolC in capsule biosynthesis. Additionally, TolC was essential for growth under iron-limiting conditions, suggesting its involvement in iron acquisition. The tolC mutant exhibited increased adherence to human enterocytes and enhanced serum sensitivity. In the Galleria mellonella infection model, the tolC mutant displayed reduced virulence compared to the wild type. Our findings highlight the pleiotropic role of TolC in K. pneumoniae pathobiology, influencing antimicrobial resistance, capsule production, iron homeostasis, adherence to host cells, and virulence. Understanding the multifaceted role of TolC in K. pneumoniae may guide the development of new therapeutic strategies against this pathogen. .
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Affiliation(s)
- X. Renee Bina
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Yuding Weng
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - James Budnick
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mia E. Van Allen
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - James E. Bina
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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10
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Meikle V, Zhang L, Niederweis M. Intricate link between siderophore secretion and drug efflux in Mycobacterium tuberculosis. Antimicrob Agents Chemother 2023; 67:e0162922. [PMID: 37676015 PMCID: PMC10583673 DOI: 10.1128/aac.01629-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 06/30/2023] [Indexed: 09/08/2023] Open
Abstract
Drug-resistant Mycobacterium tuberculosis is a worldwide health-care problem rendering current tuberculosis (TB) drugs ineffective. Drug efflux is an important mechanism in bacterial drug resistance. The MmpL4 and MmpL5 transporters form functionally redundant complexes with their associated MmpS4 and MmpS5 proteins and constitute the inner membrane components of an essential siderophore secretion system of M. tuberculosis. Inactivating siderophore secretion is toxic for M. tuberculosis due to self-poisoning at low-iron conditions and leads to a strong virulence defect in mice. In this study, we show that M. tuberculosis mutants lacking components of the MmpS4-MmpL4 and MmpS5-MmpL5 systems are more susceptible to bedaquiline, clofazimine, and rifabutin, important drugs for treatment of drug-resistant TB. While genetic deletion experiments revealed similar functions of the MmpL4 and MmpL5 transporters in siderophore and drug secretion, complementation experiments indicated that the MmpS4-MmpL4 proteins alone are not sufficient to restore drug efflux in an M. tuberculosis mutant lacking both operons, in contrast to MmpS5-MmpL5. Importantly, an M. tuberculosis mutant lacking the recently discovered periplasmic Rv0455c protein, which is also essential for siderophore secretion, is more susceptible to the same drugs. These results reveal a promising target for the development of dual-function TB drugs, which might poison M. tuberculosis by blocking siderophore secretion and synergize with other drugs by impairing drug efflux.
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Affiliation(s)
- Virginia Meikle
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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11
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Pandey SS. The Role of Iron in Phytopathogenic Microbe-Plant Interactions: Insights into Virulence and Host Immune Response. PLANTS (BASEL, SWITZERLAND) 2023; 12:3173. [PMID: 37687419 PMCID: PMC10563075 DOI: 10.3390/plants12173173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/10/2023]
Abstract
Iron is an essential element required for the growth and survival of nearly all forms of life. It serves as a catalytic component in multiple enzymatic reactions, such as photosynthesis, respiration, and DNA replication. However, the excessive accumulation of iron can result in cellular toxicity due to the production of reactive oxygen species (ROS) through the Fenton reaction. Therefore, to maintain iron homeostasis, organisms have developed a complex regulatory network at the molecular level. Besides catalyzing cellular redox reactions, iron also regulates virulence-associated functions in several microbial pathogens. Hosts and pathogens have evolved sophisticated strategies to compete against each other over iron resources. Although the role of iron in microbial pathogenesis in animals has been extensively studied, mechanistic insights into phytopathogenic microbe-plant associations remain poorly understood. Recent intensive research has provided intriguing insights into the role of iron in several plant-pathogen interactions. This review aims to describe the recent advances in understanding the role of iron in the lifestyle and virulence of phytopathogenic microbes, focusing on bacteria and host immune responses.
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Affiliation(s)
- Sheo Shankar Pandey
- Life Sciences Division, Institute of Advanced Study in Science and Technology (IASST), Guwahati 781035, India; ; Tel.: +91-361-2270095 (ext. 216)
- Citrus Research and Education Center (CREC), Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850, USA
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12
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de Miranda R, Cuthbert BJ, Klevorn T, Chao A, Mendoza J, Arbing M, Sieminski PJ, Papavinasasundaram K, Abdul-Hafiz S, Chan S, Sassetti CM, Ehrt S, Goulding CW. Differentiating the roles of Mycobacterium tuberculosis substrate binding proteins, FecB and FecB2, in iron uptake. PLoS Pathog 2023; 19:e1011650. [PMID: 37747938 PMCID: PMC10553834 DOI: 10.1371/journal.ppat.1011650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 10/05/2023] [Accepted: 08/31/2023] [Indexed: 09/27/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, poses a great threat to human health. With the emergence of drug resistant Mtb strains, new therapeutics are desperately needed. As iron is critical to the growth and survival of Mtb, mechanisms through which Mtb acquires host iron represent attractive therapeutic targets. Mtb scavenges host iron via Mtb siderophore-dependent and heme iron uptake pathways. While multiple studies describe the import of heme and ferric-siderophores and the export of apo-siderophores across the inner membrane, little is known about their transport across the periplasm and cell-wall environments. Mtb FecB and FecB2 are predicted periplasmic binding proteins implicated in host iron acquisition; however, their precise roles are not well understood. This study sought to differentiate the roles FecB and FecB2 play in Mtb iron acquisition. The crystallographic structures of Mtb FecB and FecB2 were determined to 2.0 Å and 2.2 Å resolution, respectively, and show distinct ligand binding pockets. In vitro ligand binding experiments for FecB and FecB2 were performed with heme and bacterial siderophores from Mtb and other species, revealing that both FecB and FecB2 bind heme, while only FecB binds the Mtb sideophore ferric-carboxymycobactin (Fe-cMB). Subsequent structure-guided mutagenesis of FecB identified a single glutamate residue-Glu339-that significantly contributes to Fe-cMB binding. A role for FecB in the Mtb siderophore-mediated iron acquisition pathway was corroborated by Mycobacterium smegmatis and Mtb pull-down assays, which revealed interactions between FecB and members of the mycobacterial siderophore export and import machinery. Similarly, pull-down assays with FecB2 confirms its role in heme uptake revealing interactions with a potential inner membrane heme importer. Due to ligand preference and protein partners, our data suggest that Mtb FecB plays a role in siderophore-dependent iron and heme acquisition pathways; in addition, we confirm that Mtb FecB2 is involved in heme uptake.
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Affiliation(s)
- Rodger de Miranda
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Bonnie J. Cuthbert
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Thaís Klevorn
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Alex Chao
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Jessica Mendoza
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Mark Arbing
- UCLA-DOE Institute, UCLA, Los Angeles, Calofornia, United States of America
| | - Paul J. Sieminski
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Kadamba Papavinasasundaram
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, United States of America
| | - Sumer Abdul-Hafiz
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Sum Chan
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Christopher M. Sassetti
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, United States of America
| | - Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Celia W. Goulding
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, Califiornia, United States of America
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13
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Yamasaki S, Zwama M, Yoneda T, Hayashi-Nishino M, Nishino K. Drug resistance and physiological roles of RND multidrug efflux pumps in Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001322. [PMID: 37319001 PMCID: PMC10333786 DOI: 10.1099/mic.0.001322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/18/2023] [Indexed: 06/17/2023]
Abstract
Drug efflux pumps transport antimicrobial agents out of bacteria, thereby reducing the intracellular antimicrobial concentration, which is associated with intrinsic and acquired bacterial resistance to these antimicrobials. As genome analysis has advanced, many drug efflux pump genes have been detected in the genomes of bacterial species. In addition to drug resistance, these pumps are involved in various essential physiological functions, such as bacterial adaptation to hostile environments, toxin and metabolite efflux, biofilm formation and quorum sensing. In Gram-negative bacteria, efflux pumps in the resistance–nodulation–division (RND) superfamily play a clinically important role. In this review, we focus on Gram-negative bacteria, including Salmonella enterica , Escherichia coli and Pseudomonas aeruginosa , and discuss the role of RND efflux pumps in drug resistance and physiological functions.
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Affiliation(s)
- Seiji Yamasaki
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Institute for Advanced Co-Creation Studies, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Martijn Zwama
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Tomohiro Yoneda
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Mitsuko Hayashi-Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kunihiko Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Center for Infectious Disease Education and Research, 2-8 Yamadaoka, Osaka University, Suita, Osaka 565-0871, Japan
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14
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Ávila-Nieto C, Pedreño-López N, Mitjà O, Clotet B, Blanco J, Carrillo J. Syphilis vaccine: challenges, controversies and opportunities. Front Immunol 2023; 14:1126170. [PMID: 37090699 PMCID: PMC10118025 DOI: 10.3389/fimmu.2023.1126170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
Syphilis is a sexually or vertically (mother to fetus) transmitted disease caused by the infection of Treponema pallidum subspecie pallidum (TPA). The incidence of syphilis has increased over the past years despite the fact that this bacterium is an obligate human pathogen, the infection route is well known, and the disease can be successfully treated with penicillin. As complementary measures to preventive campaigns and early treatment of infected individuals, development of a syphilis vaccine may be crucial for controlling disease spread and/or severity, particularly in countries where the effectiveness of the aforementioned measures is limited. In the last century, several vaccine prototypes have been tested in preclinical studies, mainly in rabbits. While none of them provided protection against infection, some prototypes prevented bacteria from disseminating to distal organs, attenuated lesion development, and accelerated their healing. In spite of these promising results, there is still some controversy regarding the identification of vaccine candidates and the characteristics of a syphilis-protective immune response. In this review, we describe what is known about TPA immune response, and the main mechanisms used by this pathogen to evade it. Moreover, we emphasize the importance of integrating this knowledge, in conjunction with the characterization of outer membrane proteins (OMPs), to expedite the development of a syphilis vaccine that can protect against TPA infection.
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Affiliation(s)
- Carlos Ávila-Nieto
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Autonomous University of Barcelona, Cerdanyola del Vallès, Catalonia, Spain
| | | | - Oriol Mitjà
- Skin Neglected Tropical Diseases and Sexually Transmitted Infections Department, Germans Trias i Pujol Hospital, Badalona, Spain
- Fight Infections Foundation, Germans Trias i Pujol Hospital, Badalona, Catalonia, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
| | - Bonaventura Clotet
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Fight Infections Foundation, Germans Trias i Pujol Hospital, Badalona, Catalonia, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
| | - Julià Blanco
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
| | - Jorge Carrillo
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
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15
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Ikujuni AP, Budiardjo SJ, Dhar R, Slusky JSG. Detergent headgroups control TolC folding in vitro. Biophys J 2023; 122:1185-1197. [PMID: 36772796 PMCID: PMC10111266 DOI: 10.1016/j.bpj.2023.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 12/29/2022] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
TolC is the trimeric outer membrane component of the efflux pump system in Escherichia coli that is responsible for antibiotic efflux from bacterial cells. Overexpression of efflux pumps has been reported to decrease susceptibility to antibiotics in a variety of bacterial pathogens. Reliable production of membrane proteins allows for the biophysical and structural characterization needed to better understand efflux and for the development of therapeutics. Preparation of recombinant protein for biochemical/structural studies often involves the production of proteins as inclusion body aggregates from which active proteins are recovered. Here, we find that the in vitro folding of TolC into its functional trimeric state from inclusion bodies is dependent on the headgroup composition of detergent micelles used. Nonionic detergent favors the formation of functional trimeric TolC, whereas zwitterionic detergents induce the formation of a non-native, oligomeric TolC fold. We also find that nonionic detergents with shorter alkyl lengths facilitate TolC folding. It remains to be seen whether the charges in lipid headgroups have similar effects on membrane insertion and folding in biological systems.
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Affiliation(s)
| | - S Jimmy Budiardjo
- Center for Computational Biology, The University of Kansas, Lawrence, Kansas
| | - Rik Dhar
- Department of Molecular Biosciences, The University of Kansas, Lawrence, Kansas
| | - Joanna S G Slusky
- Department of Molecular Biosciences, The University of Kansas, Lawrence, Kansas; Center for Computational Biology, The University of Kansas, Lawrence, Kansas.
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16
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Lai YH, Franke R, Pinkert L, Overwin H, Brönstrup M. Molecular Signatures of the Eagle Effect Induced by the Artificial Siderophore Conjugate LP-600 in E. coli. ACS Infect Dis 2023; 9:567-581. [PMID: 36763039 PMCID: PMC10012262 DOI: 10.1021/acsinfecdis.2c00567] [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: 02/11/2023]
Abstract
Achieving cellular uptake is a central challenge for novel antibiotics targeting Gram-negative bacterial pathogens. One strategy is to hijack the bacterial iron transport system by siderophore-antibiotic conjugates that are actively imported into the cell. This was realized with the MECAM-ampicillin conjugate LP-600 we recently reported that was highly active against E. coli. In the present study, we investigate a paradoxical regrowth of E. coli upon treatment of LP-600 at concentrations 16-32 times above the minimum inhibitory concentration (MIC). The phenomenon, coined "Eagle-effect" in other systems, was not due to resistance formation, and it occurred for the siderophore conjugate but not for free ampicillin. To investigate the molecular imprint of the Eagle effect, a combined transcriptome and untargeted metabolome analysis was conducted. LP-600 induced the expression of genes involved in iron acquisition, SOS response, and the e14 prophage upon regrowth conditions. The Eagle effect was diminished in the presence of sulbactam, which we ascribe to a putative synergistic antibiotic action but not to β-lactamase inhibition. The study highlights the relevance of the Eagle effect for siderophore conjugates. Through the first systematic -omics investigations, it also demonstrates that the Eagle effect manifests not only in a paradoxical growth but also in unique gene expression and metabolite profiles.
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Affiliation(s)
- Yi-Hui Lai
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Raimo Franke
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Lukas Pinkert
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Heike Overwin
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.,German Center for Infection Research (DZIF), Site Hannover-Braunschweig, 38124 Braunschweig, Germany.,Center of Biomolecular Drug Research (BMWZ), Leibniz University, 30159 Hannover, Germany
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17
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Chodkowski JL, Shade A. A coevolution experiment between Flavobacterium johnsoniae and Burkholderia thailandensis reveals parallel mutations that reduce antibiotic susceptibility. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36724091 DOI: 10.1099/mic.0.001267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
One interference mechanism of bacterial competition is the production of antibiotics. Bacteria exposed to antibiotics can resist antibiotic inhibition through intrinsic or acquired mechanisms. Here, we performed a coevolution experiment to understand the long-term consequences of antibiotic production and antibiotic susceptibility for two environmental bacterial strains. We grew five independent lines of the antibiotic-producing environmental strain, Burkholderia thailandensis E264, and the antibiotic-inhibited environmental strain, Flavobacterium johnsoniae UW101, together and separately on agar plates for 7.5 months (1.5 month incubations), transferring each line five times to new agar plates. We observed that the F. johnsoniae ancestor could tolerate the B. thailandensis-produced antibiotic through efflux mechanisms, but that the coevolved lines had reduced susceptibility. We then sequenced genomes from the coevolved and monoculture F. johnsoniae lines, and uncovered mutational ramifications for the long-term antibiotic exposure. The coevolved genomes from F. johnsoniae revealed four potential mutational signatures of reduced antibiotic susceptibility that were not observed in the evolved monoculture lines. Two mutations were found in tolC: one corresponding to a 33 bp deletion and the other corresponding to a nonsynonymous mutation. A third mutation was observed as a 1 bp insertion coding for a RagB/SusD nutrient uptake protein. The last mutation was a G83R nonsynonymous mutation in acetyl-coA carboxylayse carboxyltransferase subunit alpha (AccA). Deleting the 33 bp from tolC in the F. johnsoniae ancestor reduced antibiotic susceptibility, but not to the degree observed in coevolved lines. Furthermore, the accA mutation matched a previously described mutation conferring resistance to B. thailandensis-produced thailandamide. Analysis of B. thailandensis transposon mutants for thailandamide production revealed that thailandamide was bioactive against F. johnsoniae, but also suggested that additional B. thailandensis-produced antibiotics were involved in the inhibition of F. johnsoniae. This study reveals how multi-generational interspecies interactions, mediated through chemical exchange, can result in novel interaction-specific mutations, some of which may contribute to reductions in antibiotic susceptibility.
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Affiliation(s)
- John L Chodkowski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Ashley Shade
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.,Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA.,Program in Ecology, Evolution and Behavior, Michigan State University, East Lansing, MI 48824, USA.,Univ Lyon, CNRS, INSA Lyon, Université Claude Bernard Lyon 1, Ecole Centrale de Lyon, Ampère, UMR5005, 69134, Ecully cedex, France
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18
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Bhattacharyya S, Bhattacharyya M, Pfannenstiel DM, Nandi AK, Hwang Y, Ho K, Harshey RM. Efflux-linked accelerated evolution of antibiotic resistance at a population edge. Mol Cell 2022; 82:4368-4385.e6. [PMID: 36400010 PMCID: PMC9699456 DOI: 10.1016/j.molcel.2022.10.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/22/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022]
Abstract
Efflux is a common mechanism of resistance to antibiotics. We show that efflux itself promotes accumulation of antibiotic-resistance mutations (ARMs). This phenomenon was initially discovered in a bacterial swarm where the linked phenotypes of high efflux and high mutation frequencies spatially segregated to the edge, driven there by motility. We have uncovered and validated a global regulatory network connecting high efflux to downregulation of specific DNA-repair pathways even in non-swarming states. The efflux-DNA repair link was corroborated in a clinical "resistome" database: genomes with mutations that increase efflux exhibit a significant increase in ARMs. Accordingly, efflux inhibitors decreased evolvability to antibiotic resistance. Swarms also revealed how bacterial populations serve as a reservoir of ARMs even in the absence of antibiotic selection pressure. High efflux at the edge births mutants that, despite compromised fitness, survive there because of reduced competition. This finding is relevant to biofilms where efflux activity is high.
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Affiliation(s)
- Souvik Bhattacharyya
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA.
| | | | - Dylan M Pfannenstiel
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Anjan K Nandi
- Department of Physical Sciences, Indian Institute of Science Education & Research, Kolkata, India
| | - YuneSahng Hwang
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Khang Ho
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Rasika M Harshey
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA.
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19
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Identification of Key Functions Required for Production and Utilization of the Siderophore Piscibactin Encoded by the High-Pathogenicity Island irp-HPI in Vibrionaceae. Int J Mol Sci 2022; 23:ijms23168865. [PMID: 36012135 PMCID: PMC9408133 DOI: 10.3390/ijms23168865] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/27/2022] [Accepted: 08/05/2022] [Indexed: 11/17/2022] Open
Abstract
Piscibactin is a widespread siderophore system present in many different bacteria, especially within the Vibrionaceae family. Previous works showed that most functions required for biosynthesis and transport of this siderophore are encoded by the high-pathogenicity island irp-HPI. In the present work, using Vibrio anguillarum as a model, we could identify additional key functions encoded by irp-HPI that are necessary for piscibactin production and transport and that have remained unknown. Allelic exchange mutagenesis, combined with cross-feeding bioassays and LC-MS analysis, were used to demonstrate that Irp4 protein is an essential component for piscibactin synthesis since it is the thioesterase required for nascent piscibactin be released from the NRPS Irp1. We also show that Irp8 is a MFS-type protein essential for piscibactin secretion. In addition, after passage through the outer membrane transporter FrpA, the completion of ferri-piscibactin internalization through the inner membrane would be achieved by the ABC-type transporter FrpBC. The expression of this transporter is coordinated with the expression of FrpA and with the genes encoding biosynthetic functions. Since piscibactin is a major virulence factor of some pathogenic vibrios, the elements of biosynthesis and transport described here could be additional interesting targets for the design of novel antimicrobials against these bacterial pathogens.
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Evidence of an intracellular interaction between the Escherichia coli enzymes EntC and EntB and identification of a potential electrostatic channeling surface. Biochimie 2022; 202:159-165. [PMID: 35952947 DOI: 10.1016/j.biochi.2022.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 11/23/2022]
Abstract
Siderophores are high-affinity small-molecule chelators employed by bacteria to acquire iron from the extracellular environment. The Gram-negative bacterium Escherichia coli synthesizes and secretes enterobactin, a tris-catechol siderophore. Enterobactin is synthesized by six cytoplasmic enzyme activities: EntC, EntB (isochorismatase (IC) domain), EntA, EntE, EntB (aryl carrier protein (ArCP) domain), and EntF. While various pairwise protein-protein interactions have been reported between EntB, EntA, EntE, and EntF, evidence for an interaction between EntC and EntB has remained elusive. We have employed bacterial two-hybrid assays and in vivo crosslinking to demonstrate an intracellular EntC-EntB interaction. A T18-EntC/T25-EntB co-transformant exhibited a positive two-hybrid signal compared to a control T18-EntC/T25 co-transformant. In vivo formaldehyde crosslinking of E. coli cells co-expressing HA-tagged EntB and H6-tagged EntC resulted in an observable ∼80 kDa band on Western blots that cross-reacted with anti-HA and anti-H6, corresponding to one HA-EntB monomer (33 kDa) crosslinked with one H6-EntC monomer (45 kDa). This band disappeared upon sample boiling, confirming it to be a formaldehyde-crosslinked species. Bands of molecular masses greater than 80 kDa that cross-reacted with both antibodies were also observed. Automated docking of the crystal structures of monomeric EntC and dimeric EntB resulted in a top-ranked candidate docked ensemble in which the active sites of EntC and EntB were oriented in apposition and connected by an electropositive surface potentially capable of channeling negatively charged isochorismate. These research outcomes provide the first reported evidence of an EntC-EntB interaction, as well as the first experimental evidence of higher-order complexes containing EntC and EntB.
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21
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Soares EV. Perspective on the biotechnological production of bacterial siderophores and their use. Appl Microbiol Biotechnol 2022. [PMID: 35672469 DOI: 10.1007/s00253-022-11995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Iron (Fe) is an essential element in several fundamental cellular processes. Although present in high amounts in the Earth's crust, Fe can be a scarce element due to its low bioavailability. To mitigate Fe limitation, microorganism (bacteria and fungi) and grass plant biosynthesis and secret secondary metabolites, called siderophores, with capacity to chelate Fe(III) with high affinity and selectivity. This review focuses on the current state of knowledge concerning the production of siderophores by bacteria. The main siderophore types and corresponding siderophore-producing bacteria are summarized. A concise outline of siderophore biosynthesis, secretion and regulation is given. Important aspects to be taken into account in the selection of a siderophore-producing bacterium, such as biological safety, complexing properties of the siderophores and amount of siderophores produced are summarized and discussed. An overview containing recent scientific advances on culture medium formulation and cultural conditions that influence the production of siderophores by bacteria is critically presented. The recovery, purification and processing of siderophores are outlined. Potential applications of siderophores in different sectors including agriculture, environment, biosensors and the medical field are sketched. Finally, future trends regarding the production and use of siderophores are discussed. KEY POINTS : • An overview of siderophore production by bacteria is critically presented • Scientific advances on factors that influence siderophores production are discussed • Potential applications of siderophores, in different fields, are outlined.
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Affiliation(s)
- Eduardo V Soares
- Bioengineering Laboratory, ISEP-School of Engineering, Polytechnic Institute of Porto, rua Dr António Bernardino de Almeida, 431, 4249-015, Porto, Portugal.
- CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
- LABBELS - Associate Laboratory, Braga-Guimaraes, Portugal.
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22
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Soares EV. Perspective on the biotechnological production of bacterial siderophores and their use. Appl Microbiol Biotechnol 2022; 106:3985-4004. [PMID: 35672469 DOI: 10.1007/s00253-022-11995-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 11/29/2022]
Abstract
Iron (Fe) is an essential element in several fundamental cellular processes. Although present in high amounts in the Earth's crust, Fe can be a scarce element due to its low bioavailability. To mitigate Fe limitation, microorganism (bacteria and fungi) and grass plant biosynthesis and secret secondary metabolites, called siderophores, with capacity to chelate Fe(III) with high affinity and selectivity. This review focuses on the current state of knowledge concerning the production of siderophores by bacteria. The main siderophore types and corresponding siderophore-producing bacteria are summarized. A concise outline of siderophore biosynthesis, secretion and regulation is given. Important aspects to be taken into account in the selection of a siderophore-producing bacterium, such as biological safety, complexing properties of the siderophores and amount of siderophores produced are summarized and discussed. An overview containing recent scientific advances on culture medium formulation and cultural conditions that influence the production of siderophores by bacteria is critically presented. The recovery, purification and processing of siderophores are outlined. Potential applications of siderophores in different sectors including agriculture, environment, biosensors and the medical field are sketched. Finally, future trends regarding the production and use of siderophores are discussed. KEY POINTS : • An overview of siderophore production by bacteria is critically presented • Scientific advances on factors that influence siderophores production are discussed • Potential applications of siderophores, in different fields, are outlined.
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Affiliation(s)
- Eduardo V Soares
- Bioengineering Laboratory, ISEP-School of Engineering, Polytechnic Institute of Porto, rua Dr António Bernardino de Almeida, 431, 4249-015, Porto, Portugal. .,CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal. .,LABBELS - Associate Laboratory, Braga-Guimaraes, Portugal.
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23
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Zhang L, Kent JE, Whitaker M, Young DC, Herrmann D, Aleshin AE, Ko YH, Cingolani G, Saad JS, Moody DB, Marassi FM, Ehrt S, Niederweis M. A periplasmic cinched protein is required for siderophore secretion and virulence of Mycobacterium tuberculosis. Nat Commun 2022; 13:2255. [PMID: 35474308 PMCID: PMC9042941 DOI: 10.1038/s41467-022-29873-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
Iron is essential for growth of Mycobacterium tuberculosis, the causative agent of tuberculosis. To acquire iron from the host, M. tuberculosis uses the siderophores called mycobactins and carboxymycobactins. Here, we show that the rv0455c gene is essential for M. tuberculosis to grow in low-iron medium and that secretion of both mycobactins and carboxymycobactins is drastically reduced in the rv0455c deletion mutant. Both water-soluble and membrane-anchored Rv0455c are functional in siderophore secretion, supporting an intracellular role. Lack of Rv0455c results in siderophore toxicity, a phenotype observed for other siderophore secretion mutants, and severely impairs replication of M. tuberculosis in mice, demonstrating the importance of Rv0455c and siderophore secretion during disease. The crystal structure of a Rv0455c homolog reveals a novel protein fold consisting of a helical bundle with a 'cinch' formed by an essential intramolecular disulfide bond. These findings advance our understanding of the distinct M. tuberculosis siderophore secretion system.
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Affiliation(s)
- Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - James E Kent
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Meredith Whitaker
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - David C Young
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Dominik Herrmann
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Alexander E Aleshin
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Ying-Hui Ko
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Jamil S Saad
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - D Branch Moody
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Francesca M Marassi
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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24
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Wellawa DH, Lam PKS, White AP, Gomis S, Allan B, Köster W. High Affinity Iron Acquisition Systems Facilitate but Are Not Essential for Colonization of Chickens by Salmonella Enteritidis. Front Microbiol 2022; 13:824052. [PMID: 35308377 PMCID: PMC8928163 DOI: 10.3389/fmicb.2022.824052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 01/24/2022] [Indexed: 01/02/2023] Open
Abstract
The roles of TonB mediated Fe3+ (ferric iron) uptake via enterobactin (involving biosynthesis genes entABCDEF) and Fe2+ (ferrous iron) uptake through the FeoABC transporter are poorly defined in the context of chicken-Salmonella interactions. Both uptake systems are believed to be the major contributors of iron supply in the Salmonella life cycle. Current evidence suggests that these iron uptake systems play a major role in pathogenesis in mammals and as such, they represent promising antibacterial targets with therapeutic potential. We investigated the role of these iron uptake mechanisms regarding the ability of Salmonella Enteritidis (SEn) strains to colonize in a chicken infection model. Further we constructed a bioluminescent reporter to sense iron limitation during gastrointestinal colonization of Salmonella in chicken via ex vivo imaging. Our data indicated that there is some redundancy between the ferric and ferrous iron uptake mechanisms regarding iron acquisition during SEn pathogenesis in chicken. We believe that this redundancy of iron acquisition in the host reservoir may be the consequence of adaptation to unique avian environments, and thus warrants further investigation. To our knowledge, this the first report providing direct evidence that both enterobactin synthesis and FeoABC mediated iron uptake contribute to the virulence of SEn in chickens.
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Affiliation(s)
- Dinesh H Wellawa
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Po-King S Lam
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada
| | - Aaron P White
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Susantha Gomis
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Brenda Allan
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Wolfgang Köster
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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25
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Iron-Utilization System in Vibrio vulnificus M2799. Mar Drugs 2021; 19:md19120710. [PMID: 34940709 PMCID: PMC8706444 DOI: 10.3390/md19120710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/10/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022] Open
Abstract
Vibrio vulnificus is a Gram-negative pathogenic bacterium that causes serious infections in humans and requires iron for growth. A clinical isolate, V. vulnificus M2799, secretes a catecholate siderophore, vulnibactin, that captures ferric ions from the environment. In the ferric-utilization system in V. vulnificus M2799, an isochorismate synthase (ICS) and an outer membrane receptor, VuuA, are required under low-iron conditions, but alternative proteins FatB and VuuB can function as a periplasmic-binding protein and a ferric-chelate reductase, respectively. The vulnibactin-export system is assembled from TolCV1 and several RND proteins, including VV1_1681. In heme acquisition, HupA and HvtA serve as specific outer membrane receptors and HupB is a sole periplasmic-binding protein, unlike FatB in the ferric-vulnibactin utilization system. We propose that ferric-siderophore periplasmic-binding proteins and ferric-chelate reductases are potential targets for drug discovery in infectious diseases.
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26
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Abstract
Iron is an essential element for Escherichia, Salmonella, and Shigella species. The acquisition of sufficient amounts of iron is difficult in many environments, including the intestinal tract, where these bacteria usually reside. Members of these genera have multiple iron transport systems to transport both ferrous and ferric iron. These include transporters for free ferrous iron, ferric iron associated with chelators, and heme. The numbers and types of transport systems in any species reflect the diversity of niches that it can inhabit. Many of the iron transport genes are found on mobile genetic elements or pathogenicity islands, and there is evidence of the spread of the genes among different species and pathotypes. This is notable among the pathogenic members of the genera in which iron transport systems acquired by horizontal gene transfer allow the bacteria to overcome host innate defenses that act to restrict the availability of iron to the pathogen. The need for iron is balanced by the need to avoid iron overload since excess iron is toxic to the cell. Genes for iron transport and metabolism are tightly regulated and respond to environmental cues, including iron availability, oxygen, and temperature. Master regulators, the iron sensor Fur and the Fur-regulated small RNA (sRNA) RyhB, coordinate the expression of iron transport and cellular metabolism genes in response to the availability of iron.
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27
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Sepúlveda-Correa A, Daza-Giraldo LV, Polanía J, Arenas NE, Muñoz-García A, Sandoval-Figueredo AV, Vanegas J. Genes associated with antibiotic tolerance and synthesis of antimicrobial compounds in a mangrove with contrasting salinities. MARINE POLLUTION BULLETIN 2021; 171:112740. [PMID: 34304060 DOI: 10.1016/j.marpolbul.2021.112740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/22/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Salinity and wastewater pollution in mangrove ecosystems can affect microorganisms and the abundance of genes involved in response to these stressors. This research aimed to identify genes associated with resistance and biosynthesis of antimicrobial compounds in mangrove soils subjected to contrasting salinities and wastewater pollution. Samples of rhizospheric soil were taken from a mangrove at the mouth of the Ranchería River in La Guajira, Colombia. A functional analysis was performed using Illumina HiSeq 2500 sequencing data obtained from total DNA extracted. Increased salt concentration influenced metabolic pathways and differential abundance of genes associated with the synthesis of antimicrobial compounds (e.g., rfbB/rffG, INO1/ISYNA1, rfbA/rffH, sat/met3, asd). Also, among 33 genes involved in intrinsic antibiotic resistance, 16 were significantly influenced by salinity (e.g., cusR/copR/silR, vgb, tolC). We concluded that salt stress tolerance and adaptive mechanisms could favor the biosynthesis of antimicrobial compounds in mangroves contaminated by sewage.
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Affiliation(s)
| | | | - Jaime Polanía
- Universidad Nacional de Colombia Sede Medellín, Cra. 65 #59a-110, Medellín, Colombia
| | - Nelson E Arenas
- Universidad Antonio Nariño, Sede Circunvalar, Cra 3 Este No. 47 A 15, Bogotá, Colombia
| | | | | | - Javier Vanegas
- Universidad Antonio Nariño, Sede Circunvalar, Cra 3 Este No. 47 A 15, Bogotá, Colombia.
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28
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Pajarillo EAB, Lee E, Kang DK. Trace metals and animal health: Interplay of the gut microbiota with iron, manganese, zinc, and copper. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2021; 7:750-761. [PMID: 34466679 PMCID: PMC8379138 DOI: 10.1016/j.aninu.2021.03.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/27/2021] [Accepted: 03/16/2021] [Indexed: 12/27/2022]
Abstract
Metals such as iron, manganese, copper, and zinc are recognized as essential trace elements. These trace metals play critical roles in development, growth, and metabolism, participating in various metabolic processes by acting as cofactors of enzymes or providing structural support to proteins. Deficiency or toxicity of these metals can impact human and animal health, giving rise to a number of metabolic and neurological disorders. Proper breakdown, absorption, and elimination of these trace metals is a tightly regulated process that requires crosstalk between the host and these micronutrients. The gut is a complex system that serves as the interface between these components, but other factors that contribute to this delicate interaction are not well understood. The gut is home to trillions of microorganisms and microbial genes (the gut microbiome) that can regulate the metabolism and transport of micronutrients and contribute to the bioavailability of trace metals through their assimilation from food sources or by competing with the host. Furthermore, deficiency or toxicity of these metals can modulate the gut microenvironment, including microbiota, nutrient availability, stress, and immunity. Thus, understanding the role of the gut microbiota in the metabolism of manganese, iron, copper, and zinc, as well as in heavy metal deficiencies and toxicities, and vice versa, may provide insight into developing improved or alternative therapeutic strategies to address emerging health concerns. This review describes the current understanding of how the gut microbiome and trace metals interact and affect host health, particularly in pigs.
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Affiliation(s)
- Edward Alain B. Pajarillo
- Department of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee 32307, FL, USA
| | - Eunsook Lee
- Department of Animal Resources Science, Dankook University, Cheonan 31116, Republic of Korea
| | - Dae-Kyung Kang
- Department of Animal Resources Science, Dankook University, Cheonan 31116, Republic of Korea
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29
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Matuszewska M, Maciąg T, Rajewska M, Wierzbicka A, Jafra S. The carbon source-dependent pattern of antimicrobial activity and gene expression in Pseudomonas donghuensis P482. Sci Rep 2021; 11:10994. [PMID: 34040089 PMCID: PMC8154892 DOI: 10.1038/s41598-021-90488-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/12/2021] [Indexed: 02/04/2023] Open
Abstract
Pseudomonas donghuensis P482 is a tomato rhizosphere isolate with the ability to inhibit growth of bacterial and fungal plant pathogens. Herein, we analysed the impact of the carbon source on the antibacterial activity of P482 and expression of the selected genes of three genomic regions in the P482 genome. These regions are involved in the synthesis of pyoverdine, 7-hydroxytropolone (7-HT) and an unknown compound ("cluster 17") and are responsible for the antimicrobial activity of P482. We showed that the P482 mutants, defective in these regions, show variations and contrasting patterns of growth inhibition of the target pathogen under given nutritional conditions (with glucose or glycerol as a carbon source). We also selected and validated the reference genes for gene expression studies in P. donghuensis P482. Amongst ten candidate genes, we found gyrB, rpoD and mrdA the most stably expressed. Using selected reference genes in RT-qPCR, we assessed the expression of the genes of interest under minimal medium conditions with glucose or glycerol as carbon sources. Glycerol was shown to negatively affect the expression of genes necessary for 7-HT synthesis. The significance of this finding in the light of the role of nutrient (carbon) availability in biological plant protection is discussed.
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Affiliation(s)
- Marta Matuszewska
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland
| | - Tomasz Maciąg
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland
| | - Magdalena Rajewska
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland
| | - Aldona Wierzbicka
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland
| | - Sylwia Jafra
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland.
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30
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Jackson M, Stevens CM, Zhang L, Zgurskaya HI, Niederweis M. Transporters Involved in the Biogenesis and Functionalization of the Mycobacterial Cell Envelope. Chem Rev 2021; 121:5124-5157. [PMID: 33170669 PMCID: PMC8107195 DOI: 10.1021/acs.chemrev.0c00869] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The biology of mycobacteria is dominated by a complex cell envelope of unique composition and structure and of exceptionally low permeability. This cell envelope is the basis of many of the pathogenic features of mycobacteria and the site of susceptibility and resistance to many antibiotics and host defense mechanisms. This review is focused on the transporters that assemble and functionalize this complex structure. It highlights both the progress and the limits of our understanding of how (lipo)polysaccharides, (glyco)lipids, and other bacterial secretion products are translocated across the different layers of the cell envelope to their final extra-cytoplasmic location. It further describes some of the unique strategies evolved by mycobacteria to import nutrients and other products through this highly impermeable barrier.
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Affiliation(s)
- Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1682, USA
| | - Casey M. Stevens
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, USA
| | - Helen I. Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, USA
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31
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Schuster S, Vavra M, Greim L, Kern WV. Exploring the Contribution of the AcrB Homolog MdtF to Drug Resistance and Dye Efflux in a Multidrug Resistant E. coli Isolate. Antibiotics (Basel) 2021; 10:antibiotics10050503. [PMID: 33925175 PMCID: PMC8145115 DOI: 10.3390/antibiotics10050503] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/16/2022] Open
Abstract
In Escherichia coli, the role of RND-type drug transporters other than the major efflux pump AcrB has largely remained undeciphered (particularly in multidrug resistant pathogens), because genetic engineering in such isolates is challenging. The present study aimed to explore the capability of the AcrB homolog MdtF to contribute to the extrusion of noxious compounds and to multidrug resistance in an E. coli clinical isolate with demonstrated expression of this efflux pump. An mdtF/acrB double-knockout was engineered, and susceptibility changes with drugs from various classes were determined in comparison to the parental strain and its acrB and tolC single-knockout mutants. The potential of MdtF to participate in the export of agents with different physicochemical properties was additionally assessed using accumulation and real-time efflux assays with several fluorescent dyes. The results show that there was limited impact to the multidrug resistant phenotype in the tested E. coli strain, while the RND-type transporter remarkably contributes to the efflux of all tested dyes. This should be considered when evaluating the efflux phenotype of clinical isolates via dye accumulation assays. Furthermore, the promiscuity of MdtF should be taken into account when developing new antibiotic agents.
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Affiliation(s)
- Sabine Schuster
- Division of Infectious Diseases, Department of Medicine II, University Hospital and Medical Center, 79106 Freiburg, Germany; (M.V.); (L.G.); (W.V.K.)
- Correspondence:
| | - Martina Vavra
- Division of Infectious Diseases, Department of Medicine II, University Hospital and Medical Center, 79106 Freiburg, Germany; (M.V.); (L.G.); (W.V.K.)
| | - Ludwig Greim
- Division of Infectious Diseases, Department of Medicine II, University Hospital and Medical Center, 79106 Freiburg, Germany; (M.V.); (L.G.); (W.V.K.)
| | - Winfried V. Kern
- Division of Infectious Diseases, Department of Medicine II, University Hospital and Medical Center, 79106 Freiburg, Germany; (M.V.); (L.G.); (W.V.K.)
- Faculty of Medicine, Albert-Ludwigs-University, 79106 Freiburg, Germany
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32
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Henderson PJF, Maher C, Elbourne LDH, Eijkelkamp BA, Paulsen IT, Hassan KA. Physiological Functions of Bacterial "Multidrug" Efflux Pumps. Chem Rev 2021; 121:5417-5478. [PMID: 33761243 DOI: 10.1021/acs.chemrev.0c01226] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacterial multidrug efflux pumps have come to prominence in human and veterinary pathogenesis because they help bacteria protect themselves against the antimicrobials used to overcome their infections. However, it is increasingly realized that many, probably most, such pumps have physiological roles that are distinct from protection of bacteria against antimicrobials administered by humans. Here we undertake a broad survey of the proteins involved, allied to detailed examples of their evolution, energetics, structures, chemical recognition, and molecular mechanisms, together with the experimental strategies that enable rapid and economical progress in understanding their true physiological roles. Once these roles are established, the knowledge can be harnessed to design more effective drugs, improve existing microbial production of drugs for clinical practice and of feedstocks for commercial exploitation, and even develop more sustainable biological processes that avoid, for example, utilization of petroleum.
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Affiliation(s)
- Peter J F Henderson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Claire Maher
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia
| | - Liam D H Elbourne
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Bart A Eijkelkamp
- College of Science and Engineering, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Ian T Paulsen
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
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Teelucksingh T, Thompson LK, Cox G. The Evolutionary Conservation of Escherichia coli Drug Efflux Pumps Supports Physiological Functions. J Bacteriol 2020; 202:e00367-20. [PMID: 32839176 PMCID: PMC7585057 DOI: 10.1128/jb.00367-20] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Bacteria harness an impressive repertoire of resistance mechanisms to evade the inhibitory action of antibiotics. One such mechanism involves efflux pump-mediated extrusion of drugs from the bacterial cell, which significantly contributes to multidrug resistance. Intriguingly, most drug efflux pumps are chromosomally encoded components of the intrinsic antibiotic resistome. In addition, in terms of xenobiotic detoxification, bacterial efflux systems often exhibit significant levels of functional redundancy. Efflux pumps are also considered to be highly conserved; however, the extent of conservation in many bacterial species has not been reported and the majority of genes that encode efflux pumps appear to be dispensable for growth. These observations, in combination with an increasing body of experimental evidence, imply alternative roles in bacterial physiology. Indeed, the ability of efflux pumps to facilitate antibiotic resistance could be a fortuitous by-product of ancient physiological functions. Using Escherichia coli as a model organism, we here evaluated the evolutionary conservation of drug efflux pumps and we provide phylogenetic analysis of the major efflux families. We show the E. coli drug efflux system has remained relatively stable and the majority (∼80%) of pumps are encoded in the core genome. This analysis further supports the importance of drug efflux pumps in E. coli physiology. In this review, we also provide an update on the roles of drug efflux pumps in the detoxification of endogenously synthesized substrates and pH homeostasis. Overall, gaining insight into drug efflux pump conservation, common evolutionary ancestors, and physiological functions could enable strategies to combat these intrinsic and ancient elements.
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Affiliation(s)
- Tanisha Teelucksingh
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Laura K Thompson
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Georgina Cox
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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Gomez NO, Tetard A, Ouerdane L, Laffont C, Brutesco C, Ball G, Lobinski R, Denis Y, Plésiat P, Llanes C, Arnoux P, Voulhoux R. Involvement of the Pseudomonas aeruginosa MexAB-OprM efflux pump in the secretion of the metallophore pseudopaline. Mol Microbiol 2020; 115:84-98. [PMID: 32896017 DOI: 10.1111/mmi.14600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/07/2020] [Accepted: 08/28/2020] [Indexed: 12/16/2022]
Abstract
To overcome the metal restriction imposed by the host's nutritional immunity, pathogenic bacteria use high metal affinity molecules called metallophores. Metallophore-mediated metal uptake pathways necessitate complex cycles of synthesis, secretion, and recovery of the metallophore across the bacterial envelope. We recently discovered staphylopine and pseudopaline, two members of a new family of broad-spectrum metallophores important for bacterial survival during infections. Here, we are expending the molecular understanding of the pseudopaline transport cycle across the diderm envelope of the Gram-negative bacterium Pseudomonas aeruginosa. We first explored pseudopaline secretion by performing in vivo quantifications in various genetic backgrounds and revealed the specific involvement of the MexAB-OprM efflux pump in pseudopaline transport across the outer membrane. We then addressed the recovery part of the cycle by investigating the fate of the recaptured metal-loaded pseudopaline. To do so, we combined in vitro reconstitution experiments and in vivo phenotyping in absence of pseudopaline transporters to reveal the existence of a pseudopaline modification mechanism, possibly involved in the metal release following pseudopaline recovery. Overall, our data allowed us to provide an improved molecular model of secretion, recovery, and fate of this important metallophore by P. aeruginosa.
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Affiliation(s)
- Nicolas Oswaldo Gomez
- Laboratoire de Chimie Bactérienne (LCB) UMR7283, Institut de Microbiologie de la Méditerranée (IMM), CNRS, Aix-Marseille Université, Marseille, France
| | - Alexandre Tetard
- Laboratoire de Bactériologie, UMR CNRS 6249 Chrono-Environnement, Faculté de Médecine-Pharmacie, Université de Bourgogne Franche-Comté, Besançon, France
| | - Laurent Ouerdane
- Université de Pau et des Pays de l'Adour, e2s UPPA, CNRS, IPREM-UMR5254, Hélioparc, Pau, France
| | - Clémentine Laffont
- CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies d'Aix-Marseille, UMR, CEA Cadarache, Saint-Paul-lez Durance, France
| | - Catherine Brutesco
- CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies d'Aix-Marseille, UMR, CEA Cadarache, Saint-Paul-lez Durance, France
| | - Geneviève Ball
- Laboratoire de Chimie Bactérienne (LCB) UMR7283, Institut de Microbiologie de la Méditerranée (IMM), CNRS, Aix-Marseille Université, Marseille, France
| | - Ryszard Lobinski
- Université de Pau et des Pays de l'Adour, e2s UPPA, CNRS, IPREM-UMR5254, Hélioparc, Pau, France
| | - Yann Denis
- CNRS, Aix-Marseille Université, Institut de Microbiologie de la Méditerranée (IMM), Marseille, France
| | - Patrick Plésiat
- Laboratoire de Bactériologie, UMR CNRS 6249 Chrono-Environnement, Faculté de Médecine-Pharmacie, Université de Bourgogne Franche-Comté, Besançon, France
| | - Catherine Llanes
- Laboratoire de Bactériologie, UMR CNRS 6249 Chrono-Environnement, Faculté de Médecine-Pharmacie, Université de Bourgogne Franche-Comté, Besançon, France
| | - Pascal Arnoux
- CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies d'Aix-Marseille, UMR, CEA Cadarache, Saint-Paul-lez Durance, France
| | - Romé Voulhoux
- Laboratoire de Chimie Bactérienne (LCB) UMR7283, Institut de Microbiologie de la Méditerranée (IMM), CNRS, Aix-Marseille Université, Marseille, France
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Zhang Y, Sen S, Giedroc DP. Iron Acquisition by Bacterial Pathogens: Beyond Tris-Catecholate Complexes. Chembiochem 2020; 21:1955-1967. [PMID: 32180318 PMCID: PMC7367709 DOI: 10.1002/cbic.201900778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/06/2020] [Indexed: 12/11/2022]
Abstract
Sequestration of the essential nutrient iron from bacterial invaders that colonize the vertebrate host is a central feature of nutritional immunity and the "fight over transition metals" at the host-pathogen interface. The iron quota for many bacterial pathogens is large, as iron enzymes often make up a significant share of the metalloproteome. Iron enzymes play critical roles in respiration, energy metabolism, and other cellular processes by catalyzing a wide range of oxidation-reduction, electron transfer, and oxygen activation reactions. In this Concept article, we discuss recent insights into the diverse ways that bacterial pathogens acquire this essential nutrient, beyond the well-characterized tris-catecholate FeIII complexes, in competition and cooperation with significant host efforts to cripple these processes. We also discuss pathogen strategies to adapt their metabolism to less-than-optimal iron concentrations, and briefly speculate on what might be an integrated adaptive response to the concurrent limitation of both iron and zinc in the infected host.
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Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Sambuddha Sen
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
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Linearized Siderophore Products Secreted via MacAB Efflux Pump Protect Salmonella enterica Serovar Typhimurium from Oxidative Stress. mBio 2020; 11:mBio.00528-20. [PMID: 32371597 PMCID: PMC7403778 DOI: 10.1128/mbio.00528-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Nontyphoidal Salmonella bacteria induce a classic inflammatory diarrhea by eliciting a large influx of neutrophils, producing a robust oxidative burst. Despite substantial progress understanding the benefits to the host of the inflammatory response to Salmonella, little is known regarding how Salmonella can simultaneously resist the damaging effects of the oxidative burst. The multidrug efflux pump MacAB is important for survival of oxidative stress both in vitro and during infection. We describe a new pathway used by Salmonella Typhimurium to detoxify extracellular reactive oxygen species using a multidrug efflux pump (MacAB) to secrete a linear siderophore, a metabolite of enterobactin. The natural substrates of many multidrug efflux pumps are unknown, and functional roles of the linear metabolites of enterobactin are unknown. We bring two novel discoveries together to highlight an important mechanism used by Salmonella to survive under the oxidative stress conditions that this organism encounters during the classic inflammatory diarrhea that it also induces. Nontyphoidal salmonellae (NTS) are exposed to reactive oxygen species (ROS) during their residency in the gut. To survive oxidative stress encountered during infection, salmonellae employ several mechanisms. One of these mechanisms involves the multidrug efflux pump MacAB, although the natural substrate of this pump has not been identified. MacAB homologs in pseudomonads secrete products of nonribosomal peptide synthesis (NRPS). In Salmonella enterica serovar Typhimurium, the siderophore enterobactin is produced by NRPS in response to iron starvation and this molecule can be processed into salmochelin and several linear metabolites. We found that Salmonella mutants lacking the key NRPS enzyme EntF are sensitive to peroxide mediated killing and cannot detoxify extracellular H2O2. Moreover, EntF and MacAB function in a common pathway to promote survival of Salmonella during oxidative stress. We further demonstrated that S. Typhimurium secretes siderophores in iron-rich media when peroxide is present and that these MacAB-secreted metabolites participate in protection of bacteria against H2O2. We showed that secretion of anti-H2O2 molecules is independent of the presence of the known siderophore efflux pumps EntS and IroC, well-described efflux systems involved in secretion of enterobactin and salmochelin. Both salmochelin and enterobactin are dispensable for S. Typhimurium protection against ROS; however, linear metabolites of enterobactin produced by esterases IroE and Fes are needed for bacterial survival in peroxide-containing media. We determined that linearized enterobactin trimer protects S. Typhimurium against peroxide-mediated killing in a MacAB-dependent fashion. Thus, we suggest that linearized enterobactin trimer is a natural substrate of MacAB and that its purpose is to detoxify extracellular reactive oxygen species.
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37
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RNase E-dependent degradation of tnaA mRNA encoding tryptophanase is prerequisite for the induction of acid resistance in Escherichia coli. Sci Rep 2020; 10:7128. [PMID: 32346014 PMCID: PMC7188888 DOI: 10.1038/s41598-020-63981-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/09/2020] [Indexed: 01/25/2023] Open
Abstract
Acid-resistance systems are essential for pathogenic Escherichia coli to survive in the strongly acidic environment of the human stomach (pH < 2.5). Among these, the glutamic acid decarboxylase (GAD) system is the most effective. However, the precise mechanism of GAD induction is unknown. We previously reported that a tolC mutant lacking the TolC outer membrane channel was defective in GAD induction. Here, we show that indole, a substrate of TolC-dependent efflux pumps and produced by the tryptophanase encoded by the tnaA gene, negatively regulates GAD expression. GAD expression was restored by deleting tnaA in the tolC mutant; in wild-type E. coli, it was suppressed by adding indole to the growth medium. RNA-sequencing revealed that tnaA mRNA levels drastically decreased upon exposure to moderately acidic conditions (pH 5.5). This decrease was suppressed by RNase E deficiency. Collectively, our results demonstrate that the RNase E-dependent degradation of tnaA mRNA is accelerated upon acid exposure, which decreases intracellular indole concentrations and triggers GAD induction.
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EntE, EntS and TolC synergistically contributed to the pathogenesis of APEC strain E058. Microb Pathog 2020; 141:103990. [PMID: 31978427 DOI: 10.1016/j.micpath.2020.103990] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 01/19/2020] [Accepted: 01/20/2020] [Indexed: 01/18/2023]
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) shows an enhanced ability to cause infection outside the intestinal tract. Avian pathogenic E. coli (APEC), one type of ExPEC, causes avian colibacillosis, a disease of significant economic importance to poultry producers worldwide that is characterized by systemic infection. Some ExPEC strains as well as other pathogenic enterobacteria produce enterobactin, a catecholate siderophore used to sequester iron during infection. Here, we showed that disruption of enterobactin efflux via outer membrane protein TolC significantly decreased the pathogenicity of APEC strain E058. Furthermore, colonization and persistence assays performed using a chicken infection model showed that the ΔtolC mutant was obviously attenuated (p˂0.001). In contrast, disruption of enterobactin synthesis gene entE and/or the inner membrane transporter gene entS had little effect on pathogenicity. Analysis of growth kinetics revealed a significant reduction in the growth of triple mutant strain E058ΔentEΔentSΔtolC in iron-deficient medium compared with the wild-type strain (p˂0.001), while no growth impairment was noted for the E058ΔtolC mutant in either Luria-Bertani broth or iron-deficient medium. The E058ΔentEΔentSΔtolC mutant also showed significantly decreased virulence compared with single mutant strain E058ΔtolC. Low-copy complementation of strains E058ΔtolC and E058ΔentEΔentSΔtolC with plasmid-borne tolC restored virulence to wild-type levels in the chicken infection model. Macrophage infection assays showed that ingestion of E058ΔtolC by macrophage cell line HD11 cells was reduced compared with ingestion of the E058ΔentEΔentSΔtolC mutant. However, no significant differences were observed between the mutants and the wild-type in a chicken serum resistance assay. Together, these results suggest that EntE, EntS and TolC synergistically contributed to the pathogenesis of APEC strain E058 in an iron-deficient environment.
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Guest RL, Court EA, Waldon JL, Schock KA, Raivio TL. Impaired Efflux of the Siderophore Enterobactin Induces Envelope Stress in Escherichia coli. Front Microbiol 2019; 10:2776. [PMID: 31866967 PMCID: PMC6908949 DOI: 10.3389/fmicb.2019.02776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/14/2019] [Indexed: 01/04/2023] Open
Abstract
The Cpx response is one of several envelope stress responses that monitor and maintain the integrity of the gram-negative bacterial envelope. While several conditions that are known or predicted to generate misfolded inner membrane proteins activate the Cpx response, the molecular nature of the Cpx inducing cue is not yet known. Studies have demonstrated that mutation of multidrug efflux pumps activates the Cpx response in many gram-negative bacteria. In Vibrio cholerae, pathway activation is due to accumulation of the catechol siderophore vibriobactin. However, the mechanism by which the Cpx response is activated by mutation of efflux pumps in Escherichia coli remains unknown. Here we show that inhibition of efflux by deletion of tolC, the outer membrane channel of several multidrug efflux pumps, activates the Cpx response in E. coli as a result of impaired efflux of the siderophore enterobactin. Enterobactin accumulation in the tolC mutant reduces activity of the nicotinamide adenine dinucleotide (NADH) oxidation arm of the aerobic respiratory chain. However, the Cpx pathway remains active in the tolC mutant when either NADH dehydrogenase I, NADH dehydrogenase II, or cytochrome bo3 is absent. Finally, we show that the Cpx response down-regulates transcription of the enterobactin biosynthesis operon. These results suggest that the Cpx response promotes adaptation to envelope stress in enteric bacteria that are exposed to iron-limited environments, which are rich in envelope-damaging compounds and conditions.
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Affiliation(s)
- Randi L Guest
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Emily A Court
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Jayne L Waldon
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Kiersten A Schock
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Tracy L Raivio
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
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Structure of ribosome-bound azole-modified peptide phazolicin rationalizes its species-specific mode of bacterial translation inhibition. Nat Commun 2019; 10:4563. [PMID: 31594941 PMCID: PMC6783444 DOI: 10.1038/s41467-019-12589-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 09/09/2019] [Indexed: 02/04/2023] Open
Abstract
Ribosome-synthesized post-translationally modified peptides (RiPPs) represent a rapidly expanding class of natural products with various biological activities. Linear azol(in)e-containing peptides (LAPs) comprise a subclass of RiPPs that display outstanding diversity of mechanisms of action while sharing common structural features. Here, we report the discovery of a new LAP biosynthetic gene cluster in the genome of Rhizobium Pop5, which encodes the precursor peptide and modification machinery of phazolicin (PHZ) – an extensively modified peptide exhibiting narrow-spectrum antibacterial activity against some symbiotic bacteria of leguminous plants. The cryo-EM structure of the Escherichia coli 70S-PHZ complex reveals that the drug interacts with the 23S rRNA and uL4/uL22 proteins and obstructs ribosomal exit tunnel in a way that is distinct from other compounds. We show that the uL4 loop sequence determines the species-specificity of antibiotic action. PHZ expands the known diversity of LAPs and may be used in the future as biocontrol agent for agricultural needs. The authors report the identification of phazolicin (PHZ) - a prokaryotic translation inhibitory peptide - and its structure in complex with the E. coli ribosome, delineating PHZ’s mode of action and suggesting a basis for its bacterial species-specific activity.
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41
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Chen C, Hooper DC. Intracellular accumulation of staphylopine impairs the fitness of Staphylococcus aureus cntE mutant. FEBS Lett 2019; 593:1213-1222. [PMID: 31045247 DOI: 10.1002/1873-3468.13396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/18/2019] [Accepted: 04/23/2019] [Indexed: 01/29/2023]
Abstract
Staphylococcus aureus exports staphylopine (StP), a broad-spectrum metallophore, via the CntE efflux pump. Here, the mechanism of the fitness defect in the ΔcntE mutant under metal depletion was investigated. Deletion of the StP exporter CntE results in a substantial growth defect, and disrupting the StP biosynthesis gene cntL restores growth of the ΔcntE mutant in metal-depleted media. High-resolution mass spectrometry revealed cytoplasmic accumulation of StP and the absence of extracellular StP in the ΔcntE mutant. The fitness defect of the ΔcntE mutant in mouse subcutaneous abscesses is largely due to StP accumulation. Expression of StP biosynthesis genes are upregulated in the ΔcntE mutant under metal starvation induction. In conclusion, failure to efflux StP results in intracellular StP accumulation and substantially impairs the fitness of S. aureus.
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Affiliation(s)
- Chunhui Chen
- Division of Infectious Diseases, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - David C Hooper
- Division of Infectious Diseases, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
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Raspoet R, Eeckhaut V, Vermeulen K, De Smet L, Wen Y, Nishino K, Haesebrouck F, Ducatelle R, Devreese B, Van Immerseel F. The Salmonella Enteritidis TolC outer membrane channel is essential for egg white survival. Poult Sci 2019; 98:2281-2289. [PMID: 30624709 DOI: 10.3382/ps/pey584] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/10/2018] [Indexed: 01/06/2023] Open
Abstract
Salmonella Enteritidis has developed the potential to contaminate eggs by surviving in the antimicrobial environment of the hen's egg white. This has led to a worldwide pandemic of foodborne salmonellosis infections in humans due to the consumption of contaminated eggs and egg-derived products. The molecular mechanisms of Salmonella Enteritidis egg white survival are not fully clear. Using in vivo expression technology and promoter-reporter fusions we showed that the promoter of the tolC gene, encoding the TolC outer membrane channel that is used by multidrug efflux pumps to export harmful molecules and to secrete bacterial products, is activated by egg white at the chicken body temperature. Using a Salmonella Enteritidis tolC deletion mutant we showed that TolC has an important role in egg white survival. Chromatographic separation techniques and subsequent testing of antimicrobial activities of separated egg white fractions led to the identification of ovotransferrin as the egg white antimicrobial factor which is capable of inhibiting growth of a tolC deletion strain but not the wild type strain. We provide evidence that TolC protects Salmonella Enteritidis against ovotransferrin-mediated growth inhibition in egg white.
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Affiliation(s)
- R Raspoet
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - V Eeckhaut
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - K Vermeulen
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - L De Smet
- Department of Physiology, Faculty of Sciences, Ghent University, Krijgslaan 281 S2, 9000 Ghent, Belgium.,Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Y Wen
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - K Nishino
- Laboratory of Microbiology and Infectious Diseases, Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - F Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - R Ducatelle
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - B Devreese
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - F Van Immerseel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
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Post SJ, Shapiro JA, Wuest WM. Connecting iron acquisition and biofilm formation in the ESKAPE pathogens as a strategy for combatting antibiotic resistance. MEDCHEMCOMM 2019; 10:505-512. [PMID: 31057729 PMCID: PMC6482887 DOI: 10.1039/c9md00032a] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/20/2019] [Indexed: 12/24/2022]
Abstract
The rise of antibiotic resistant bacteria has become a problem of global concern. Of particular interest are the ESKAPE pathogens, species with high rates of multi-drug resistant infections. Novel antibiotic mechanisms of action are necessary to compliment traditional therapeutics. Recent research has focused on targeting virulence factors as a method of combatting infection without creating selective pressure for resistance or damaging the host commensal microbiome. Some investigations into one such virulence behavior, iron acquisition, have displayed additional effects on another virulence behavior, biofilm formation. The use of exogenous iron-chelators, gallium as an iron mimic, and inhibition of siderophore-mediated iron acquisition are all strategies for disturbing iron-homeostasis that have implicated effects on biofilms. However, the exact nature of this connection remains ambiguous. Herein we summarize these findings and identify opportunities for further investigation.
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Affiliation(s)
- Savannah J Post
- Department of Chemistry , Emory University , Atlanta , GA 30322 , USA .
| | - Justin A Shapiro
- Department of Chemistry , Emory University , Atlanta , GA 30322 , USA .
| | - William M Wuest
- Department of Chemistry , Emory University , Atlanta , GA 30322 , USA .
- Antibiotic Resistance Center , Emory University School of Medicine , Atlanta , GA 30322 , USA
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Comprehensive analysis of resistance-nodulation-cell division superfamily (RND) efflux pumps from Serratia marcescens, Db10. Sci Rep 2019; 9:4854. [PMID: 30890721 PMCID: PMC6425002 DOI: 10.1038/s41598-019-41237-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/05/2019] [Indexed: 12/29/2022] Open
Abstract
We investigated the role of the resistance-nodulation-cell division superfamily (RND) efflux system on intrinsic multidrug resistance in Serratia marcescens. We identified eight putative RND efflux system genes in the S. marcescens Db10 genome that included the previously characterized systems, sdeXY, sdeAB, and sdeCDE. Six out of the eight genes conferred multidrug resistance on KAM32, a drug hypersensitive strain of Escherichia coli. Five out of the eight genes conferred resistance to benzalkonium, suggesting the importance of RND efflux systems in biocide resistance in S. marcescens. The energy-dependent efflux activities of five of the pumps were examined using a rhodamine 6 G efflux assay. When expressed in the tolC-deficient strain of E. coli, KAM43, none of the genes conferred resistance on E. coli. When hasF, encoding the S. marcescens TolC ortholog, was expressed in KAM43, all of the genes conferred resistance on E. coli, suggesting that HasF is a major outer membrane protein that is used by all RND efflux systems in this organism. We constructed a sdeXY deletion mutant from a derivative strain of the clinically isolated multidrug-resistant S. marcescens strain and found that the sdeXY deletion mutant was sensitive to a broad spectrum of antimicrobial agents.
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45
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The anti-bacterial iron-restriction defence mechanisms of egg white; the potential role of three lipocalin-like proteins in resistance against Salmonella. Biometals 2019; 32:453-467. [PMID: 30810876 PMCID: PMC6584246 DOI: 10.1007/s10534-019-00180-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 01/25/2019] [Indexed: 11/26/2022]
Abstract
Salmonella enterica serovar Enteritidis (SE) is the most frequently-detected Salmonella in foodborne outbreaks in the European Union. Among such outbreaks, egg and egg products were identified as the most common vehicles of infection. Possibly, the major antibacterial property of egg white is iron restriction, which results from the presence of the iron-binding protein, ovotransferrin. To circumvent iron restriction, SE synthesise catecholate siderophores (i.e. enterobactin and salmochelin) that can chelate iron from host iron-binding proteins. Here, we highlight the role of lipocalin-like proteins found in egg white that could enhance egg-white iron restriction through sequestration of certain siderophores, including enterobactin. Indeed, it is now apparent that the egg-white lipocalin, Ex-FABP, can inhibit bacterial growth via its siderophore-binding capacity in vitro. However, it remains unclear whether Ex-FABP performs such a function in egg white or during bird infection. Regarding the two other lipocalins of egg white (Cal-γ and α-1-glycoprotein), there is currently no evidence to indicate that they sequester siderophores.
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Conley ZC, Carlson-Banning KM, Carter AG, de la Cova A, Song Y, Zechiedrich L. Sugar and iron: Toward understanding the antibacterial effect of ciclopirox in Escherichia coli. PLoS One 2019; 14:e0210547. [PMID: 30633761 PMCID: PMC6329577 DOI: 10.1371/journal.pone.0210547] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/27/2018] [Indexed: 12/11/2022] Open
Abstract
New antibiotics are needed against antibiotic-resistant gram-negative bacteria. The repurposed antifungal drug, ciclopirox, equally blocks antibiotic-susceptible or multidrug-resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae clinical isolates, indicating that it is not affected by existing resistance mechanisms. Toward understanding how ciclopirox blocks growth, we screened E. coli mutant strains and found that disruption of genes encoding products involved in galactose salvage, enterobacterial common antigen synthesis, and transport of the iron binding siderophore, enterobactin, lowered the minimum inhibitory concentration of ciclopirox needed to block growth of the mutant compared to the isogenic parent strain. We found that ciclopirox induced enterobactin production and that this effect is strongly affected by the deletion of the galactose salvage genes encoding UDP-galactose 4-epimerase, galE, or galactose-1-phosphate uridylyltransferase, galT. As disruption of ECA synthesis activates the regulation of capsular synthesis (Rcs) phosphorelay, which inhibits bacterial swarming and promotes biofilm development, we test whether ciclopirox prevents activation of the Rcs pathway. Sub-inhibitory concentrations of ciclopirox increased swarming of the E. coli laboratory K12 strain BW25113 but had widely varying effects on swarming or surface motility of clinical isolate E. coli, A. baumannii, and K. pneumoniae. There was no effect of ciclopirox on biofilm production, suggesting it does not target Rcs. Altogether, our data suggest ciclopirox-mediated alteration of lipopolysaccharides stimulates enterobactin production and affects bacterial swarming.
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Affiliation(s)
- Zachary C. Conley
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Kimberly M. Carlson-Banning
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ashley G. Carter
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alejandro de la Cova
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Yongcheng Song
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lynn Zechiedrich
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, United States of America
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Chao A, Sieminski PJ, Owens CP, Goulding CW. Iron Acquisition in Mycobacterium tuberculosis. Chem Rev 2018; 119:1193-1220. [PMID: 30474981 DOI: 10.1021/acs.chemrev.8b00285] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The highly contagious disease tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis (Mtb), which has been evolving drug resistance at an alarming rate. Like all human pathogens, Mtb requires iron for growth and virulence. Consequently, Mtb iron transport is an emerging drug target. However, the development of anti-TB drugs aimed at these metabolic pathways has been restricted by the dearth of information on Mtb iron acquisition. In this Review, we describe the multiple strategies utilized by Mtb to acquire ferric iron and heme iron. Mtb iron uptake is a complex process, requiring biosynthesis and subsequent export of Mtb siderophores, followed by ferric iron scavenging and ferric-siderophore import into Mtb. Additionally, Mtb possesses two possible heme uptake pathways and an Mtb-specific mechanism of heme degradation that yields iron and novel heme-degradation products. We conclude with perspectives for potential therapeutics that could directly target Mtb heme and iron uptake machineries. We also highlight how hijacking Mtb heme and iron acquisition pathways for drug import may facilitate drug transport through the notoriously impregnable Mtb cell wall.
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Affiliation(s)
| | | | - Cedric P Owens
- Schmid College of Science and Technology , Chapman University , Orange , California 92866 , United States
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Washington-Hughes CL, Ford GT, Jones AD, McRae K, Outten FW. Nickel exposure reduces enterobactin production in Escherichia coli. Microbiologyopen 2018; 8:e00691. [PMID: 30062714 PMCID: PMC6460284 DOI: 10.1002/mbo3.691] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 12/26/2022] Open
Abstract
Escherichia coli is a well‐studied bacterium that can be found in many niches, such as industrial wastewater, where the concentration of nickel can rise to low‐millimolar levels. Recent studies show that nickel exposure can repress pyochelin or induce pyoverdine siderophore production in Pseudomonas aueroginosa. Understanding the molecular cross‐talk between siderophore production, metal homeostasis, and metal toxicity in microorganisms is critical for designing bioremediation strategies for metal‐contaminated sites. Here, we show that high‐nickel exposure prolongs lag phase duration as a result of low‐intracellular iron levels in E. coli. Although E. coli cells respond to low‐intracellular iron during nickel stress by maintaining high expression of iron uptake systems such as fepA, the demand for iron is not met due to a lack of siderophores in the extracellular medium during nickel stress. Taken together, these results indicate that nickel inhibits iron accumulation in E. coli by reducing the presence of enterobactin in the extracellular medium.
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Affiliation(s)
| | - Geoffrey T Ford
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
| | - Alsten D Jones
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
| | - Kimberly McRae
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
| | - F Wayne Outten
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
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Mateus A, Bobonis J, Kurzawa N, Stein F, Helm D, Hevler J, Typas A, Savitski MM. Thermal proteome profiling in bacteria: probing protein state in vivo. Mol Syst Biol 2018; 14:e8242. [PMID: 29980614 PMCID: PMC6056769 DOI: 10.15252/msb.20188242] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Increasing antibiotic resistance urges for new technologies for studying microbes and antimicrobial mechanism of action. We adapted thermal proteome profiling (TPP) to probe the thermostability of Escherichia coli proteins in vivoE. coli had a more thermostable proteome than human cells, with protein thermostability depending on subcellular location-forming a high-to-low gradient from the cell surface to the cytoplasm. While subunits of protein complexes residing in one compartment melted similarly, protein complexes spanning compartments often had their subunits melting in a location-wise manner. Monitoring the E. coli meltome and proteome at different growth phases captured changes in metabolism. Cells lacking TolC, a component of multiple efflux pumps, exhibited major physiological changes, including differential thermostability and levels of its interaction partners, signaling cascades, and periplasmic quality control. Finally, we combined in vitro and in vivo TPP to identify targets of known antimicrobial drugs and to map their downstream effects. In conclusion, we demonstrate that TPP can be used in bacteria to probe protein complex architecture, metabolic pathways, and intracellular drug target engagement.
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Affiliation(s)
- André Mateus
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jacob Bobonis
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Nils Kurzawa
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Frank Stein
- Proteomics Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Dominic Helm
- Proteomics Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Johannes Hevler
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Athanasios Typas
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Mikhail M Savitski
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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Selection and validation of reference genes for gene expression studies in Klebsiella pneumoniae using Reverse Transcription Quantitative real-time PCR. Sci Rep 2018; 8:9001. [PMID: 29899556 PMCID: PMC5998039 DOI: 10.1038/s41598-018-27420-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/23/2018] [Indexed: 12/27/2022] Open
Abstract
For reliable results, Reverse Transcription Quantitative real-time Polymerase Chain Reaction (RT-qPCR) analyses depend on stably expressed reference genes for data normalization purposes. Klebsiella pneumoniae is an opportunistic Gram-negative bacterium that has become a serious threat worldwide. Unfortunately, there is no consensus for an ideal reference gene for RT-qPCR data normalization on K. pneumoniae. In this study, the expression profile of eleven candidate reference genes was assessed in K. pneumoniae cells submitted to various experimental conditions, and the expression stability of these candidate genes was evaluated using statistical algorithms BestKeeper, NormFinder, geNorm, Delta CT and RefFinder. The statistical analyses ranked recA, rho, proC and rpoD as the most suitable reference genes for accurate RT-qPCR data normalization in K. pneumoniae. The reliability of the proposed reference genes was validated by normalizing the relative expression of iron-regulated genes in K. pneumoniae cells submitted to iron-replete and iron-limited conditions. This work emphasizes that the stable expression of any potential reference candidate gene must be validated in each physiological condition or experimental treatment under study.
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