1
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Akhtar AA, Turner DP. The role of bacterial ATP-binding cassette (ABC) transporters in pathogenesis and virulence: Therapeutic and vaccine potential. Microb Pathog 2022; 171:105734. [PMID: 36007845 DOI: 10.1016/j.micpath.2022.105734] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022]
Abstract
The ATP-binding cassette (ABC) transporter superfamily is found in all domains of life, facilitating critical biological processes through the translocation of a wide variety of substrates from, ions to proteins, across cellular membranes in an ATP-coupled process. The role of ABC transporters in eukaryotes has been well established: the facilitation of genetic diseases and multi-drug resistance (MDR) in cancer patients. In contrast, the role of ABC transporters in prokaryotes has been ambiguous due to their diverse functions and the sheer number of organisms in which they reside. This review examines the role of bacterial ABC transporters in pathogenesis and virulence, and their potential for therapeutic and vaccine application. We demonstrate how ABC transporters play a vital role in the virulence and pathogenesis of several pathogenic bacteria through the import of essential molecules, such as metal ions, amino acids, peptides, vitamins and osmoprotectants, as well as, the export of virulent determinants involved in glycoconjugate biosynthesis and Type I secretion. Furthermore, ABC exporters facilitate the persistence of pathogenic bacteria through the export of toxic xenobiotic substances, thus, contributing to the development of antimicrobial resistance. We also show that ABC transporters display considerable potential for therapeutic application through immunisation and resistance reversal. In conclusion, bacterial ABC transporters play an immense role in virulence and pathogenesis and display desirable traits for clinical use, therefore, potentially aiding in the battle against MDR.
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Affiliation(s)
- Armaan A Akhtar
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
| | - David Pj Turner
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
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2
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Bile salts regulate zinc uptake and capsule synthesis in a mastitis-associated extraintestinal pathogenic Escherichia coli strain. Infect Immun 2021; 89:e0035721. [PMID: 34228495 DOI: 10.1128/iai.00357-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) are major causes of urinary and bloodstream infections. ExPEC reservoirs are not completely understood. Some mastitis-associated E. coli (MAEC) strains carry genes associated with ExPEC virulence, including metal scavenging, immune avoidance, and host attachment functions. In this study, we investigated the role of the high-affinity zinc uptake (znuABC) system in the MAEC strain M12. Elimination of znuABC moderately decreased fitness during mouse mammary gland infections. The ΔznuABC mutant strain exhibited an unexpected growth delay in the presence of bile salts, which was alleviated by the addition of excess zinc. We isolated ΔznuABC mutant suppressor mutants with improved growth of in bile salts, several of which no longer produced the K96 capsule made by strain M12. Addition of bile salts also reduced capsule production by strain M12 and ExPEC strain CP9, suggesting that capsule synthesis may be detrimental when bile salts are present. To better understand the role of the capsule, we compared the virulence of mastitis strain M12 with its unencapsulated ΔkpsCS mutant in two models of ExPEC disease. The wild type strain successfully colonized mouse bladders and kidneys and was highly virulent in intraperitoneal infections. Conversely, the ΔkpsCS mutant was unable to colonize kidneys and was unable to cause sepsis. These results demonstrate that some MAEC may be capable of causing human ExPEC illness. Virulence of strain M12 in these infections is dependent on its capsule. However, capsule may interfere with zinc homeostasis in the presence of bile salts while in the digestive tract.
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3
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Cai R, Gao F, Pan J, Hao X, Yu Z, Qu Y, Li J, Wang D, Wang Y, Shen X, Liu X, Yang Y. The transcriptional regulator Zur regulates the expression of ZnuABC and T6SS4 in response to stresses in Yersinia pseudotuberculosis. Microbiol Res 2021; 249:126787. [PMID: 33991717 DOI: 10.1016/j.micres.2021.126787] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/28/2021] [Accepted: 05/07/2021] [Indexed: 01/21/2023]
Abstract
Zinc homeostasis is crucial for the development and stress resistance of bacteria in the environment. Serial zinc sensing transcriptional regulators, zinc transporters and zinc binding proteins were found to maintain the zinc homeostasis in bacteria. Zur is a zinc uptake regulator that is widely distributed in species, and ZnuABC, as well as the Type VI Secretion System (T6SS4) function in zinc acquisition. Here, we report that the regulator Zur inhibits the expression of the ZnuABC which inhibition could be eliminated at low zinc level, and upregulates the T6SS4 operon in Yersinia pseudotuberculosis to facilitate Zn2+ uptake and oxidative stress resistance. Zur regulates the expression of ZnuABC and T6SS4 by directly binding to their promoter regions. Zur senses the Zn2+ concentration and represses ZnuABC in a Zn2+-containing environment. Zur works as an auxiliary regular activator of T6SS4, facilitating oxidative stress resistance. This study revealed the dual function of regulator Zur on ZnuABC and T6SS4, and enriched the knowledge of Zn2+ homeostasis maintenance in Y. pseudotuberculosis.
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Affiliation(s)
- Ran Cai
- Beijing Capital Co., LTD, Beijing, 100044, China
| | - Fen Gao
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Junfeng Pan
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Xinwei Hao
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Zonglan Yu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Yichen Qu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Jialin Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Dandan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Xingyu Liu
- General Research Institute for Nonferrous Metals, Beijing, 100088, China.
| | - Yantao Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, China.
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4
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Xia P, Lian S, Wu Y, Yan L, Quan G, Zhu G. Zinc is an important inter-kingdom signal between the host and microbe. Vet Res 2021; 52:39. [PMID: 33663613 PMCID: PMC7931793 DOI: 10.1186/s13567-021-00913-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/08/2021] [Indexed: 12/15/2022] Open
Abstract
Zinc (Zn) is an essential trace element in living organisms and plays a vital role in the regulation of both microbial virulence and host immune responses. A growing number of studies have shown that zinc deficiency or the internal Zn concentration does not meet the needs of animals and microbes, leading to an imbalance in zinc homeostasis and intracellular signalling pathway dysregulation. Competition for zinc ions (Zn2+) between microbes and the host exists in the use of Zn2+ to maintain cell structure and physiological functions. It also affects the interplay between microbial virulence factors and their specific receptors in the host. This review will focus on the role of Zn in the crosstalk between the host and microbe, especially for changes in microbial pathogenesis and nociceptive neuron-immune interactions, as it may lead to new ways to prevent or treat microbial infections.
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Affiliation(s)
- Pengpeng Xia
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China. .,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
| | - Siqi Lian
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Yunping Wu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Li Yan
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Guomei Quan
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Guoqiang Zhu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China. .,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
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5
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Quan G, Xia P, Lian S, Wu Y, Zhu G. Zinc uptake system ZnuACB is essential for maintaining pathogenic phenotype of F4ac + enterotoxigenic E. coli (ETEC) under a zinc restricted environment. Vet Res 2020; 51:127. [PMID: 33028391 PMCID: PMC7539401 DOI: 10.1186/s13567-020-00854-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 09/22/2020] [Indexed: 01/19/2023] Open
Abstract
Zinc is the second trace element of living organisms after iron. Given its crucial importance, mammalian hosts restrict the bioavailability of Zinc ions (Zn2+) to bacterial pathogens. As a countermeasure, pathogens utilize high affinity Zn2+ transporters, such as ZnuACB to compete with the host for zinc. It is essential for bacteria to maintain zinc homeostasis and thus maintain their physiology and pathogenesis. In an attempt to uncover the zinc transporter in F4+ enterotoxigenic E. coli (ETEC) C83902, we analyzed two RNA-seq data sets of bacteria samples when different zinc treatments (restriction or abundance) were applied. Considering data revealing that the high affinity zinc uptake system ZnuACB acts as the main transporter in ETEC C83902 to resist zinc deficiency, we deleted znuACB genes to study the role of them in ETEC C83902. The deletion of znuACB genes results in growth perturbation and a sharp decrease in the ability of biofilm formation and adhesion of bacteria in vitro. Taking the data together, this study demonstrates that the ZnuACB system is required for ETEC C83902 to acquire zinc, which highly contributes to ETEC pathogenicity as well.
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Affiliation(s)
- Guomei Quan
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Pengpeng Xia
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
| | - Siqi Lian
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Yunping Wu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Guoqiang Zhu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
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6
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Mastropasqua MC, Lamont I, Martin LW, Reid DW, D'Orazio M, Battistoni A. Efficient zinc uptake is critical for the ability of Pseudomonas aeruginosa to express virulence traits and colonize the human lung. J Trace Elem Med Biol 2018; 48:74-80. [PMID: 29773197 DOI: 10.1016/j.jtemb.2018.03.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/31/2018] [Accepted: 03/08/2018] [Indexed: 02/03/2023]
Abstract
We have recently shown that Pseudomonas aeruginosa, an opportunistic pathogen that chronically infects the lungs of patients with cystic fibrosis (CF) and other forms of lung disease, is extremely efficient in recruiting zinc from the environment and that this capability is required for its ability to cause acute lung infections in mice. To verify that P. aeruginosa faces zinc shortage when colonizing the lungs of human patients, we analyzed the expression of three genes that are highly induced under conditions of zinc deficiency (zrmA, dksA2 and rpmE2), in bacteria in the sputum of patients with inflammatory lung disease. All three genes were expressed in all the analyzed sputum samples to a level much higher than that of bacteria grown in zinc-containing laboratory medium, supporting the hypothesis that P. aeruginosa is under zinc starvation during lung infections. We also found that the expression of several virulence traits that play a central role in the ability of P. aeruginosa to colonize the lung is affected by disruption of the most important zinc importing systems. Virulence features dependent on zinc intake include swarming and swimming motility and the ability to form biofilms. Furthermore, alterations in zinc assimilation interfere with the synthesis of the siderophore pyoverdine, suggesting that zinc recruitment could modulate iron uptake and affect siderophore-mediated cell signaling. Our results reveal that zinc uptake is likely to play a key role in the ability of P. aeruginosa to cause chronic lung infections and strongly modulates critical virulence traits of the pathogen. Taking into account the recent discovery that zinc uptake in P. aeruginosa is promoted by the release of a small molecular weight molecule showing high affinity for zinc, our data suggest novel and effective possibilities to control lung infections by these bacteria.
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Affiliation(s)
| | - Iain Lamont
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Lois W Martin
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - David W Reid
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; The Prince Charles Hospital, Brisbane, Queensland, Australia
| | - Melania D'Orazio
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
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7
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Robinson AE, Heffernan JR, Henderson JP. The iron hand of uropathogenic Escherichia coli: the role of transition metal control in virulence. Future Microbiol 2018; 13:745-756. [PMID: 29870278 DOI: 10.2217/fmb-2017-0295] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The role of iron as a critical nutrient in pathogenic bacteria is widely regarded as having driven selection for iron acquisition systems among uropathogenic Escherichia coli (UPEC) isolates. Carriage of multiple transition metal acquisition systems in UPEC suggests that the human urinary tract manipulates metal-ion availability in many ways to resist infection. For siderophore systems in particular, recent studies have identified new roles for siderophore copper binding as well as production of siderophore-like inhibitors of iron uptake by other, competing bacterial species. Among these is a process of nutritional passivation of metal ions, in which uropathogens access these vital nutrients while simultaneously protecting themselves from their toxic potential. Here, we review these new findings within the current understanding of UPEC transition metal acquisition.
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Affiliation(s)
- Anne E Robinson
- Division of Infectious Diseases, Department of Medicine, Department of Molecular Microbiology, Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - James R Heffernan
- Division of Infectious Diseases, Department of Medicine, Department of Molecular Microbiology, Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jeffrey P Henderson
- Division of Infectious Diseases, Department of Medicine, Department of Molecular Microbiology, Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
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8
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Bergstrom A, Katko A, Adkins Z, Hill J, Cheng Z, Burnett M, Yang H, Aitha M, Mehaffey MR, Brodbelt JS, Tehrani KHME, Martin NI, Bonomo RA, Page RC, Tierney DL, Fast W, Wright GD, Crowder MW. Probing the Interaction of Aspergillomarasmine A with Metallo-β-lactamases NDM-1, VIM-2, and IMP-7. ACS Infect Dis 2018; 4:135-145. [PMID: 29091730 DOI: 10.1021/acsinfecdis.7b00106] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Metallo-β-lactamases (MBLs) are a growing threat to the continued efficacy of β-lactam antibiotics. Recently, aspergillomarasmine A (AMA) was identified as an MBL inhibitor, but the mode of inhibition was not fully characterized. Equilibrium dialysis and metal analysis studies revealed that 2 equiv of AMA effectively removes 1 equiv of Zn(II) from MBLs NDM-1, VIM-2, and IMP-7 when the MBL is at micromolar concentrations. Conversely, 1H NMR studies revealed that 2 equiv of AMA remove 2 equiv of Co(II) from Co(II)-substituted NDM-1, VIM-2, and IMP-7 when the MBL/AMA are at millimolar concentrations. Our findings reveal that AMA inhibits the MBLs by removal of the active site metal ions required for β-lactam hydrolysis among the most clinically significant MBLs.
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Affiliation(s)
- Alexander Bergstrom
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Andrew Katko
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Zach Adkins
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Jessica Hill
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Zishuo Cheng
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Mia Burnett
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Hao Yang
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Mahesh Aitha
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - M. Rachel Mehaffey
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jennifer S. Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Kamaleddin H. M. E. Tehrani
- Department of Chemical Biology and Drug
Discovery Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Nathaniel I. Martin
- Department of Chemical Biology and Drug
Discovery Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Robert A. Bonomo
- Research
Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, Ohio 44106, United States
| | - Richard C. Page
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - David L. Tierney
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
| | - Walter Fast
- Division of Chemical Biology and Medicinal Chemistry,
College of Pharmacy, University of Texas, 107 W. Dean Keeton, Austin, Texas 78712, United States
| | - Gerard D. Wright
- Michael
G DeGroote Institute for Infectious Disease and Department of Biochemistry
and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4L8, Canada
| | - Michael W. Crowder
- Department of Chemistry
and Biochemistry, Miami University, 650 East High Street, Oxford, Ohio 45056, United States
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9
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Ammendola S, D'Amico Y, Chirullo B, Drumo R, Ciavardelli D, Pasquali P, Battistoni A. Zinc is required to ensure the expression of flagella and the ability to form biofilms in Salmonella enterica sv Typhimurium. Metallomics 2017; 8:1131-1140. [PMID: 27730246 DOI: 10.1039/c6mt00108d] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Zinc is known to play a central role in bacterial physiology and pathogenesis. Here, we report that the accumulation of FliC, the structural subunit of Salmonella phase 1 flagella, is sharply reduced in a znuABC Salmonella enterica sv. Typhimurium strain grown in zinc-poor media. Consequently, this mutant strain lacks motility, unless it grows in zinc-replete environments. This phenotype is the consequence of a general downregulation of all the genes involved in the biosynthesis of flagella, suggesting that zinc is the cofactor of proteins involved in the initiation of the transcriptional regulatory cascade leading to flagella assembly. Competition experiments in mice demonstrated that aflagellated (fliBfljC) and znuABC strains are outcompeted by the wild type strain in the gastrointestinal tract. The fliBfljC strain overgrows a fliCfljBznuABC mutant strain, but the difference in gut colonization between these two strains is less striking than that between the wild type and the znuABC strains, suggesting that the downregulation of flagella contributes to the loss of virulence of Salmonella znuABC. The absence of either flagella or ZnuABC also impairs the ability of S. Typhimurium to produce biofilms. Zinc suppresses this defect in the znuABC mutant but not in the aflagellated strains, highlighting the role of flagella in biofilm organization. We have also observed an increased production of the quorum sensing signal AI-2 in the znuABC strain sensing zinc deprivation, that may further contribute to the reduced ability to form biofilms. On the whole, our study reveals novel roles of zinc in Salmonella motility and intercellular communication.
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Affiliation(s)
- Serena Ammendola
- Dipartimento di Biologia, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133 Rome, Italy.
| | - Ylenia D'Amico
- Dipartimento di Biologia, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133 Rome, Italy.
| | - Barbara Chirullo
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Rosanna Drumo
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | | | - Paolo Pasquali
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Andrea Battistoni
- Dipartimento di Biologia, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133 Rome, Italy. and Interuniversity Consortium, National Institute Biostructures and Biosystems (INBB), Rome, Italy
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10
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Yuan F, Liao Y, You W, Liu Z, Tan Y, Zheng C, BinWang, Zhou D, Tian Y, Bei W. Deletion of the znuA virulence factor attenuates Actinobacillus pleuropneumoniae and confers protection against homologous or heterologous strain challenge. Vet Microbiol 2014; 174:531-539. [PMID: 25465668 DOI: 10.1016/j.vetmic.2014.10.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/29/2014] [Accepted: 10/14/2014] [Indexed: 01/10/2023]
Abstract
The znuA gene is known to be important for growth and survival in Escherichia coli, Haemophilus spp., Neisseria gonorrhoeae, and Pasteurella multocida under low Zn(2+) conditions. This gene is also present in Actinobacillus pleuropneumoniae serotype 1; therefore, the aim of this study was to investigate the existence of a similar role for the znuA gene in the growth and virulence of this organism. A precisely defined ΔznuA deletion mutant of A. pleuropneumoniae was constructed based on the sequence of the wild-type SLW01 using transconjugation and counterselection. This mutation was found to be lethal in low-Zn(2+) medium. Furthermore, the ΔznuA mutant strain exhibited attenuated virulence (≥22-fold) as well as reduced mortality and morbidity in a murine (Balb/C) model of infection. The majority of the bacteria were cleared from the lungs within 2 weeks. The ΔznuA mutant strain caused no adverse effects in pigs at doses of up to 1.0×10(9) CFU/mL. The ΔznuA mutant strain induced a significant immune response and conferred 80% and 100% protection on immunised pigs against challenge with A. pleuropneumoniae strains belonging to homologous or heterologous serovars, respectively, compared to the blank controls. The data obtained in this study indicate the potential of the mutant ΔznuA strain for development as a live vaccine capable of inducing reliable cross-serovar protection following intratracheal immunisation.
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Affiliation(s)
- Fangyan Yuan
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China
| | - Yonghong Liao
- National Research Center for Veterinary Medicine, Luoyang Pulike Bio-engineering Co. Ltd., Luoyang 471003, Henan, China
| | - Wujin You
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Zewen Liu
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China
| | - Yongqiang Tan
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Chengkun Zheng
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - BinWang
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Danna Zhou
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China
| | - Yongxiang Tian
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China.
| | - Weicheng Bei
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
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11
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Porcheron G, Garénaux A, Proulx J, Sabri M, Dozois CM. Iron, copper, zinc, and manganese transport and regulation in pathogenic Enterobacteria: correlations between strains, site of infection and the relative importance of the different metal transport systems for virulence. Front Cell Infect Microbiol 2013; 3:90. [PMID: 24367764 PMCID: PMC3852070 DOI: 10.3389/fcimb.2013.00090] [Citation(s) in RCA: 237] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 11/18/2013] [Indexed: 02/05/2023] Open
Abstract
For all microorganisms, acquisition of metal ions is essential for survival in the environment or in their infected host. Metal ions are required in many biological processes as components of metalloproteins and serve as cofactors or structural elements for enzymes. However, it is critical for bacteria to ensure that metal uptake and availability is in accordance with physiological needs, as an imbalance in bacterial metal homeostasis is deleterious. Indeed, host defense strategies against infection either consist of metal starvation by sequestration or toxicity by the highly concentrated release of metals. To overcome these host strategies, bacteria employ a variety of metal uptake and export systems and finely regulate metal homeostasis by numerous transcriptional regulators, allowing them to adapt to changing environmental conditions. As a consequence, iron, zinc, manganese, and copper uptake systems significantly contribute to the virulence of many pathogenic bacteria. However, during the course of our experiments on the role of iron and manganese transporters in extraintestinal Escherichia coli (ExPEC) virulence, we observed that depending on the strain tested, the importance of tested systems in virulence may be different. This could be due to the different set of systems present in these strains, but literature also suggests that as each pathogen must adapt to the particular microenvironment of its site of infection, the role of each acquisition system in virulence can differ from a particular strain to another. In this review, we present the systems involved in metal transport by Enterobacteria and the main regulators responsible for their controlled expression. We also discuss the relative role of these systems depending on the pathogen and the tissues they infect.
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Affiliation(s)
- Gaëlle Porcheron
- INRS-Institut Armand Frappier Laval, QC, Canada ; Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, QC, Canada
| | - Amélie Garénaux
- INRS-Institut Armand Frappier Laval, QC, Canada ; Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, QC, Canada
| | - Julie Proulx
- INRS-Institut Armand Frappier Laval, QC, Canada ; Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, QC, Canada
| | - Mourad Sabri
- INRS-Institut Armand Frappier Laval, QC, Canada ; Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, QC, Canada
| | - Charles M Dozois
- INRS-Institut Armand Frappier Laval, QC, Canada ; Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, QC, Canada ; Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, QC, Canada
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12
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Gunasekera TS, Striebich RC, Mueller SS, Strobel EM, Ruiz ON. Transcriptional profiling suggests that multiple metabolic adaptations are required for effective proliferation of Pseudomonas aeruginosa in jet fuel. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:13449-13458. [PMID: 24164330 DOI: 10.1021/es403163k] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Fuel is a harsh environment for microbial growth. However, some bacteria can grow well due to their adaptive mechanisms. Our goal was to characterize the adaptations required for Pseudomonas aeruginosa proliferation in fuel. We have used DNA-microarrays and RT-PCR to characterize the transcriptional response of P. aeruginosa to fuel. Transcriptomics revealed that genes essential for medium- and long-chain n-alkane degradation including alkB1 and alkB2 were transcriptionally induced. Gas chromatography confirmed that P. aeruginosa possesses pathways to degrade different length n-alkanes, favoring the use of n-C11-18. Furthermore, a gamut of synergistic metabolic pathways, including porins, efflux pumps, biofilm formation, and iron transport, were transcriptionally regulated. Bioassays confirmed that efflux pumps and biofilm formation were required for growth in jet fuel. Furthermore, cell homeostasis appeared to be carefully maintained by the regulation of porins and efflux pumps. The Mex RND efflux pumps were required for fuel tolerance; blockage of these pumps precluded growth in fuel. This study provides a global understanding of the multiple metabolic adaptations required by bacteria for survival and proliferation in fuel-containing environments. This information can be applied to improve the fuel bioremediation properties of bacteria.
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Affiliation(s)
- Thusitha S Gunasekera
- University of Dayton Research Institute, University of Dayton , Dayton Ohio 45469, United States
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13
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Role of the zinc uptake ABC transporter of Moraxella catarrhalis in persistence in the respiratory tract. Infect Immun 2013; 81:3406-13. [PMID: 23817618 DOI: 10.1128/iai.00589-13] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Moraxella catarrhalis is a human respiratory tract pathogen that causes otitis media in children and lower respiratory tract infections in adults with chronic obstructive pulmonary disease. We have identified and characterized a zinc uptake ABC transporter that is present in all strains of M. catarrhalis tested. A mutant in which the znu gene cluster is knocked out shows markedly impaired growth compared to the wild type in medium that contains trace zinc; growth is restored to wild-type levels by supplementing medium with zinc but not with other divalent cations. Thermal-shift assays showed that the purified recombinant substrate binding protein ZnuA binds zinc but does not bind other divalent cations. Invasion assays with human respiratory epithelial cells demonstrated that the zinc ABC transporter of M. catarrhalis is critical for invasion of respiratory epithelial cells, an observation that is especially relevant because an intracellular reservoir of M. catarrhalis is present in the human respiratory tract and this reservoir is important for persistence. The znu knockout mutant showed marked impairment in its capacity to persist in the respiratory tract compared to the wild type in a mouse pulmonary clearance model. We conclude that the zinc uptake ABC transporter mediates uptake of zinc in environments with very low zinc concentrations and is critical for full virulence of M. catarrhalis in the respiratory tract in facilitating intracellular invasion of epithelial cells and persistence in the respiratory tract.
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14
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Remy L, Carrière M, Derré-Bobillot A, Martini C, Sanguinetti M, Borezée-Durant E. The Staphylococcus aureus Opp1 ABC transporter imports nickel and cobalt in zinc-depleted conditions and contributes to virulence. Mol Microbiol 2012; 87:730-43. [PMID: 23279021 DOI: 10.1111/mmi.12126] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2012] [Indexed: 11/27/2022]
Abstract
Metals are common enzymatic cofactors, and their acquisition must be assured under the various conditions encountered in the host. Although some strategies for acquisition of common metals such as iron and manganese have been elucidated, little is known about the conditions and mechanisms used to capture trace metals. Nickel is a transition metal required as a cofactor for several bacterial enzymes, including urease. Staphylococcus aureus does express a nickel ABC transporter, Nik, which functions in metal-replete medium and is necessary for nickel urease activity and urinary tract colonization. In this work, we identified a novel cobalt and nickel transporter, which we named Cnt (previously annotated Opp1), in the major opportunistic pathogen S. aureus. Metal transport activity was revealed by growing cells in a chemically defined medium devoid of metals. Zinc specifically inhibits Cnt-mediated nickel and cobalt uptake, on both functional and transcriptional levels. Mortality due to S. aureus cnt mutant in systemic infection and colonization of the bladder and kidneys in ascending urinary tract infection model were reduced compared to the parent strain. This study identifies a novel S. aureus trace metal transporter and its restricted conditions of activity, and establishes its role in infection.
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Affiliation(s)
- Laetitia Remy
- UMR1319 Micalis, INRA, F-78350, Jouy en Josas, France
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15
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The zinc-responsive regulon of Neisseria meningitidis comprises 17 genes under control of a Zur element. J Bacteriol 2012; 194:6594-603. [PMID: 23043002 DOI: 10.1128/jb.01091-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Zinc is a bivalent cation essential for bacterial growth and metabolism. The human pathogen Neisseria meningitidis expresses a homologue of the Zinc uptake regulator Zur, which has been postulated to repress the putative zinc uptake protein ZnuD. In this study, we elucidated the transcriptome of meningococci in response to zinc by microarrays and quantitative real-time PCR (qRT-PCR). We identified 15 genes that were repressed and two genes that were activated upon zinc addition. All transcription units (genes and operons) harbored a putative Zur binding motif in their promoter regions. A meningococcal Zur binding consensus motif (Zur box) was deduced in silico, which harbors a conserved central palindrome consisting of hexameric inverted repeats separated by three nucleotides (TGTTATDNHATAACA). In vitro binding of recombinant meningococcal Zur to this Zur box was shown for the first time using electrophoretic mobility shift assays. Zur binding to DNA depended specifically on the presence of zinc and was sensitive to mutations in the palindromic sequence. The Zur regulon among genes of unknown function comprised genes involved in zinc uptake, tRNA modification, and ribosomal assembly. In summary, this is the first study of the transcriptional response to zinc in meningococci.
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16
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Lewis VG, Ween MP, McDevitt CA. The role of ATP-binding cassette transporters in bacterial pathogenicity. PROTOPLASMA 2012; 249:919-942. [PMID: 22246051 DOI: 10.1007/s00709-011-0360-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 11/29/2011] [Indexed: 05/31/2023]
Abstract
The ATP-binding cassette transporter superfamily is present in all three domains of life. This ubiquitous class of integral membrane proteins have diverse biological functions, but their fundamental role involves the unidirectional translocation of compounds across cellular membranes in an ATP coupled process. The importance of this class of proteins in eukaryotic systems is well established as typified by their association with genetic diseases and roles in the multi-drug resistance of cancer. In stark contrast, the ABC transporters of prokaryotes have not been exhaustively investigated due to the sheer number of different roles and organisms in which they function. In this review, we examine the breadth of functions associated with microbial ABC transporters in the context of their contribution to bacterial pathogenicity and virulence.
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Affiliation(s)
- Victoria G Lewis
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, 5005, Australia
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SoxS increases the expression of the zinc uptake system ZnuACB in an Escherichia coli murine pyelonephritis model. J Bacteriol 2011; 194:1177-85. [PMID: 22210763 DOI: 10.1128/jb.05451-11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Paralogous transcriptional regulators MarA, Rob, and SoxS act individually and together to control expression of more than 80 Escherichia coli genes. Deletion of marA, rob, and soxS from an E. coli clinical isolate prevents persistence beyond 2 days postinfection in a mouse model of pyelonephritis. We used microarray analysis to identify 242 genes differentially expressed between the triple deletion mutant and its parent strain at 2 days postinfection in the kidney. One of these, znuC of the zinc transport system ZnuACB, displayed decreased expression in the triple mutant compared to that in the parental strain, and deletion of znuC from the parental strain reduced persistence. The marA rob soxS triple deletion mutant was less viable in vitro under limited-Zn and Zn-depleted conditions, while disruption of znuC caused a reduction in the growth rates for the parental and triple mutant strains to equally low levels under limited-Zn or Zn-depleted conditions. Complementation of the triple mutant with soxS, but not marA or rob, restored the parental growth rate in Zn-depleted medium, while deletion of only soxS from the parental strain led to low growth in Zn-depleted medium. Both results suggested that SoxS is a major regulator responsible for growth under Zn-depleted conditions. Gel shift experiments failed to show direct binding of SoxS to the znuCB promoter, thus suggesting indirect control of znuCB expression by SoxS. While SoxS expression in the triple mutant fully restored persistence, increased expression of znuACB via a plasmid in this mutant only partially restored wild-type levels of persistence in the kidney. This work implicates SoxS control of znuCB expression as a key factor in persistence of E. coli in murine pyelonephritis.
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18
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Lim J, Lee KM, Kim SH, Kim Y, Kim SH, Park W, Park S. YkgM and ZinT proteins are required for maintaining intracellular zinc concentration and producing curli in enterohemorrhagic Escherichia coli (EHEC) O157:H7 under zinc deficient conditions. Int J Food Microbiol 2011; 149:159-70. [DOI: 10.1016/j.ijfoodmicro.2011.06.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 04/18/2011] [Accepted: 06/21/2011] [Indexed: 11/29/2022]
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19
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Gabbianelli R, Scotti R, Ammendola S, Petrarca P, Nicolini L, Battistoni A. Role of ZnuABC and ZinT in Escherichia coli O157:H7 zinc acquisition and interaction with epithelial cells. BMC Microbiol 2011; 11:36. [PMID: 21338480 PMCID: PMC3053223 DOI: 10.1186/1471-2180-11-36] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 02/21/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Zinc is an essential element for all living cells. Recent studies have shown that the ZnuABC zinc uptake system significantly contributes to the ability of several pathogens to multiply in the infected host and cause disease, suggesting that zinc is scarcely available within different tissues of the host. To better understand the role of zinc in bacterial pathogenicity, we have undertaken a functional characterization of the role of the ZnuABC-mediated zinc uptake pathway in enterohemorrhagic Escherichia coli O157:H7. RESULTS In this work we have analyzed the expression and the role in metal uptake of ZnuA, the periplasmic component of the ZnuABC transporter, and of ZinT, another periplasmic protein which has been shown to contribute to zinc recruitment. We report that the expression of zinT and znuA, regulated by Zur, is induced in zinc-poor media, and that inactivation of either of the genes significantly decreases E. coli O157:H7 ability to grow in zinc depleted media. We also demonstrate that ZinT and ZnuA have not a redundant function in zinc homeostasis, as the role of ZinT is subordinated to the presence of ZnuA. Moreover, we have found that znuA and zinT are strongly induced in bacteria adhering to cultured epithelial cells and that lack of ZnuA affects the adhesion ability. In addition we have found that a fraction of apo-ZinT can be secreted outside the cell where the protein might sequester environmental zinc, inducing a condition of metal starvation in surrounding cells. CONCLUSIONS The here reported results demonstrate that ZnuABC plays a critical role in zinc uptake also in E. coli O157:H7 and that ZinT contributes to the ZnuA-mediated recruitment of zinc in the periplasmic space. Full functionality of the zinc import apparatus is required to facilitate bacterial adhesion to epithelial cells, indicating that the microbial ability to compete with the host cells for zinc binding is critical to establish successful infections. The observation that ZinT can be secreted when it is in the apo-form suggests that its presence in the extracellular environment may somehow contribute to metal uptake or facilitate bacterial colonization of the intestinal epithelia.
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Affiliation(s)
- Roberta Gabbianelli
- Biotechnology Service of Service for Biotechnology and Animal Welfare, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
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Zinc uptake contributes to motility and provides a competitive advantage to Proteus mirabilis during experimental urinary tract infection. Infect Immun 2010; 78:2823-33. [PMID: 20385754 DOI: 10.1128/iai.01220-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteus mirabilis, a Gram-negative bacterium, represents a common cause of complicated urinary tract infections in catheterized patients or those with functional or anatomical abnormalities of the urinary tract. ZnuB, the membrane component of the high-affinity zinc (Zn(2+)) transport system ZnuACB, was previously shown to be recognized by sera from infected mice. Since this system has been shown to contribute to virulence in other pathogens, its role in Proteus mirabilis was investigated by constructing a strain with an insertionally interrupted copy of znuC. The znuC::Kan mutant was more sensitive to zinc limitation than the wild type, was outcompeted by the wild type in minimal medium, displayed reduced swimming and swarming motility, and produced less flaA transcript and flagellin protein. The production of flagellin and swarming motility were restored by complementation with znuCB in trans. Swarming motility was also restored by the addition of Zn(2+) to the agar prior to inoculation; the addition of Fe(2+) to the agar also partially restored the swarming motility of the znuC::Kan strain, but the addition of Co(2+), Cu(2+), or Ni(2+) did not. ZnuC contributes to but is not required for virulence in the urinary tract; the znuC::Kan strain was outcompeted by the wild type during a cochallenge experiment but was able to colonize mice to levels similar to the wild-type level during independent challenge. Since we demonstrated a role for ZnuC in zinc transport, we hypothesize that there is limited zinc present in the urinary tract and P. mirabilis must scavenge this ion to colonize and persist in the host.
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