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Naka H, Haygood MG. The dual role of TonB genes in turnerbactin uptake and carbohydrate utilization in the shipworm symbiont Teredinibacter turnerae. Appl Environ Microbiol 2023; 89:e0074423. [PMID: 38009998 PMCID: PMC10734418 DOI: 10.1128/aem.00744-23] [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: 05/18/2023] [Accepted: 10/01/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE This study highlights diversity in iron acquisition and regulation in bacteria. The mechanisms of iron acquisition and its regulation in Teredinibacter turnerae, as well as its connection to cellulose utilization, a hallmark phenotype of T. turnerae, expand the paradigm of bacterial iron acquisition. Two of the four TonB genes identified in T. turnerae exhibit functional redundancy and play a crucial role in siderophore-mediated iron transport. Unlike typical TonB genes in bacteria, none of the TonB genes in T. turnerae are clearly iron regulated. This unusual regulation could be explained by another important finding in this study, namely, that the two TonB genes involved in iron transport are also essential for cellulose utilization as a carbon source, leading to the expression of TonB genes even under iron-rich conditions.
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Affiliation(s)
- Hiroaki Naka
- Department of Medicinal Chemistry, The University of Utah, Salt Lake City, Utah, USA
- Division of Genetics, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Margo G. Haygood
- Department of Medicinal Chemistry, The University of Utah, Salt Lake City, Utah, USA
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2
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Naka H, Haygood MG. The dual role of TonB genes in turnerbactin uptake and carbohydrate utilization in the shipworm symbiont Teredinibacter turnerae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529781. [PMID: 36865190 PMCID: PMC9980095 DOI: 10.1101/2023.02.23.529781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Teredinibacter turnerae is an intracellular bacterial symbiont that resides in the gills of shipworms, wood-eating bivalve mollusks. This bacterium produces a catechol siderophore, turnerbactin, required for the survival of this bacterium under iron limiting conditions. The turnerbactin biosynthetic genes are contained in one of the secondary metabolite clusters conserved among T. turnerae strains. However, Fe(III)-turnerbactin uptake mechanisms are largely unknown. Here, we show that the first gene of the cluster, fttA a homologue of Fe(III)-siderophore TonB-dependent outer membrane receptor (TBDR) genes is indispensable for iron uptake via the endogenous siderophore, turnerbactin, as well as by an exogenous siderophore, amphi-enterobactin, ubiquitously produced by marine vibrios. Furthermore, three TonB clusters containing four tonB genes were identified, and two of these genes, tonB1b and tonB2, functioned not only for iron transport but also for carbohydrate utilization when cellulose was a sole carbon source. Gene expression analysis revealed that none of the tonB genes and other genes in those clusters were clearly regulated by iron concentration while turnerbactin biosynthesis and uptake genes were up-regulated under iron limiting conditions, highlighting the importance of tonB genes even in iron rich conditions, possibly for utilization of carbohydrates derived from cellulose.
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Affiliation(s)
- Hiroaki Naka
- Department of Medicinal Chemistry, the University of Utah
- Division of Genetics, Oregon National Primate Research Center, Oregon Health & Science University
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3
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Li G, Wang MY. The role of Vibrio vulnificus virulence factors and regulators in its infection-induced sepsis. Folia Microbiol (Praha) 2019; 65:265-274. [PMID: 31840198 DOI: 10.1007/s12223-019-00763-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022]
Abstract
Due to the development of Marine aquaculture, infections caused by Vibrio vulnificus are common all over the world. Symptoms of V. vulnificus infection vary from gastrointestinal illness to septicemia. After infection with V. vulnificus, some patients showed gastrointestinal symptoms, including vomiting, fever, diarrhea, and so on. Others appeared wound infection at the site of contact with bacteria, and even developed sepsis. Once it develops into sepsis, the prognosis of patients is very poor. However, its underlying pathogenic mechanism remains largely undetermined. Growing evidence shows that it can induce primary septicemia mainly via essential virulence factors and regulators. Therefore, it is important to identify the factors that play roles in sepsis. In this review, we systematically expounded the role of V. vulnificus virulence factors and regulators in its infection-induced sepsis in order to provide useful information for the treatment and prevention of V. vulnificus.
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Affiliation(s)
- Gang Li
- Weihai Clinical Medical School, Cheeloo College of Medicine, Shandong University, Weihai, 264200, China.,Weihai Municipal Hospital, Weihai, 264200, China
| | - Ming-Yi Wang
- Weihai Clinical Medical School, Cheeloo College of Medicine, Shandong University, Weihai, 264200, China. .,Weihai Municipal Hospital, Weihai, 264200, China.
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4
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Barnes AD, Pfeifer HJ, Zbylicki BR, Roberts EK, Rudd JC, Manzo MA, Phillips EA, Berry MM, Kenton RJ. Two novel proteins, TtpB2 and TtpD2, are essential for iron transport in the TonB2 system of Vibrio vulnificus. Microbiologyopen 2019; 9:e00947. [PMID: 31595707 PMCID: PMC6957404 DOI: 10.1002/mbo3.947] [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: 07/26/2019] [Revised: 09/08/2019] [Accepted: 09/19/2019] [Indexed: 12/19/2022] Open
Abstract
In gram-negative bacteria, energy-dependent active transport of iron-bound substrates across the outer membrane is achieved through the TonB systems of proteins. Three TonB systems have been identified in the human pathogen Vibrio vulnificus. The TonB1 system contains three proteins: TonB1, ExbB1, and ExbD1. Both the TonB2 and TonB3 systems have been shown to also contain a fourth protein, TtpC2 and TtpC3, respectively. Here, we report and begin to characterize two additional proteins in the TonB2 and TonB3 systems: TtpB and TtpD. Both TtpB2 and TtpD2 are absolutely required for the function of the TonB2 system in V. vulnificus. However, although both TtpB3 and TtpD3 in the TonB3 system are related to the proteins in the TonB2 system, neither are active in iron transport. All six protein components of the TonB2 system-TonB2, ExbB2, ExbD2, TtpB2, TtpC2, and TtpD2-are essential for the uptake of both endogenously produced iron-bound siderophores and exogenous siderophores produced from other organisms. Through complementation, we have shown that V. vulnificus is capable of using different TtpD2 proteins from other Vibrio species to bring in multiple siderophores. In contrast, we also demonstrate that TtpB2 must come from V. vulnificus, and not other species within the genus, to complement mutations in the TonB2 system.
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Affiliation(s)
- Adel D Barnes
- Department of Biology, University of Portland, Portland, OR, USA
| | - Hailey J Pfeifer
- Department of Biology, University of Portland, Portland, OR, USA
| | | | - Elena K Roberts
- Department of Biology, University of Portland, Portland, OR, USA
| | - Justin C Rudd
- Department of Biology, University of Portland, Portland, OR, USA
| | - Mario A Manzo
- Department of Biology, University of Portland, Portland, OR, USA
| | | | - Michael M Berry
- Department of Biology, University of Portland, Portland, OR, USA
| | - Ryan J Kenton
- Department of Biology, University of Portland, Portland, OR, USA
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5
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Ciaccia PN, Ramachandran R, Chattoraj DK. A Requirement for Global Transcription Factor Lrp in Licensing Replication of Vibrio cholerae Chromosome 2. Front Microbiol 2018; 9:2103. [PMID: 30250457 PMCID: PMC6139311 DOI: 10.3389/fmicb.2018.02103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 08/20/2018] [Indexed: 12/28/2022] Open
Abstract
The human pathogen, Vibrio cholerae, belongs to the 10% of bacteria in which the genome is divided. Each of its two chromosomes, like bacterial chromosomes in general, replicates from a unique origin at fixed times in the cell cycle. Chr1 initiates first, and upon duplication of a site in Chr1, crtS, Chr2 replication initiates. Recent in vivo experiments demonstrate that crtS binds the Chr2-specific initiator RctB and promotes its initiator activity by remodeling it. Compared to the well-defined RctB binding sites in the Chr2 origin, crtS is an order of magnitude longer, suggesting that other factors can bind to it. We developed an in vivo screen to identify additional crtS-binding proteins and identified the global transcription factor, Lrp, as one such protein. Studies in vivo and in vitro indicate that Lrp binds to crtS and facilitates RctB binding to crtS. Chr2 replication is severely defective in the absence of Lrp, indicative of a critical role of the transcription factor in licensing Chr2 replication. Since Lrp responds to stresses such as nutrient limitation, its interaction with RctB presumably sensitizes Chr2 replication to the physiological state of the cell.
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Affiliation(s)
| | - Revathy Ramachandran
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
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6
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Ho YC, Hung FR, Weng CH, Li WT, Chuang TH, Liu TL, Lin CY, Lo CJ, Chen CL, Chen JW, Hashimoto M, Hor LI. Lrp, a global regulator, regulates the virulence of Vibrio vulnificus. J Biomed Sci 2017; 24:54. [PMID: 28800764 PMCID: PMC5554404 DOI: 10.1186/s12929-017-0361-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/04/2017] [Indexed: 12/18/2022] Open
Abstract
Background An attenuated mutant (designated NY303) of Vibrio vulnificus, which causes serious wound infection and septicemia in humans, was isolated fortuitously from a clinical strain YJ016. This mutant was defective in cytotoxicity, migration on soft agar and virulence in the mouse. The purpose of this study was to map the mutation in this attenuated mutant and further explore how the gene thus identified is involved in virulence. Methods The whole genome sequence of mutant NY303 determined by next-generation sequencing was compared with that of strain YJ016 to map the mutations. By isolating and characterizing the specific gene-knockout mutants, the gene associated with the phenotype of mutant NY303 was identified. This gene encodes a global regulator, Lrp. A mutant, YH01, deficient in Lrp was isolated and examined in vitro, in vivo and ex vivo to find the affected virulence mechanisms. The target genes of Lrp were further identified by comparing the transcriptomes, which were determined by RNA-seq, of strain YJ016 and mutant YH01. The promoters bound by Lrp were identified by genome footprinting-sequencing, and those related with virulence were further examined by electrophoretic mobility shift assay. Results A mutation in lrp was shown to be associated with the reduced cytotoxicity, chemotaxis and virulence of mutant NY303. Mutant YH01 exhibited a phenotype resembling that of mutant NY303, and was defective in colonization in the mouse and growth in mouse serum, but not the antiphagocytosis ability. 596 and 95 genes were down- and up-regulated, respectively, in mutant YH01. Many of the genes involved in secretion of the MARTX cytotoxin, chemotaxis and iron-acquisition were down-regulated in mutant YH01. The lrp gene, which was shown to be negatively autoregulated, and 7 down-regulated virulence-associated genes were bound by Lrp in their promoters. A 14-bp consensus sequence, mkCrTTkwAyTsTG, putatively recognized by Lrp was identified in the promoters of these genes. Conclusions Lrp is a global regulator involved in regulation of cytotoxicity, chemotaxis and iron-acquisition in V. vulnificus. Down-regulation of many of the genes associated with these properties may be responsible, at least partly, for loss of virulence in mutant NY303. Electronic supplementary material The online version of this article (doi:10.1186/s12929-017-0361-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yu-Chi Ho
- Department of Microbiology and Immunology, College of Medicine, Tainan, 70101, Taiwan
| | - Feng-Ru Hung
- Department of Microbiology and Immunology, College of Medicine, Tainan, 70101, Taiwan
| | - Chao-Hui Weng
- Department of Microbiology and Immunology, College of Medicine, Tainan, 70101, Taiwan
| | - Wei-Ting Li
- Department of Microbiology and Immunology, College of Medicine, Tainan, 70101, Taiwan
| | - Tzu-Hung Chuang
- Institute of Bioinformatics and Biosignal Transduction, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Tsung-Lin Liu
- Institute of Bioinformatics and Biosignal Transduction, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Ching-Yuan Lin
- Department of Physics and Graduate Institute of Biophysics, National Central University, Taoyuan, 32001, Taiwan
| | - Chien-Jung Lo
- Department of Physics and Graduate Institute of Biophysics, National Central University, Taoyuan, 32001, Taiwan
| | - Chun-Liang Chen
- Department of Microbiology and Immunology, College of Medicine, Tainan, 70101, Taiwan
| | - Jen-Wei Chen
- Department of Microbiology and Immunology, College of Medicine, Tainan, 70101, Taiwan.,Center of Infectious Disease and Signal Transduction, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Masayuki Hashimoto
- Center of Infectious Disease and Signal Transduction, National Cheng Kung University, Tainan, 70101, Taiwan.,Department of Molecular Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Lien-I Hor
- Department of Microbiology and Immunology, College of Medicine, Tainan, 70101, Taiwan. .,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.
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7
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Cusick KD, Dale JR, Fitzgerald LA, Little BJ, Biffinger JC. Adaptation to copper stress influences biofilm formation in Alteromonas macleodii. BIOFOULING 2017; 33:505-519. [PMID: 28604167 DOI: 10.1080/08927014.2017.1329423] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
An Alteromonas macleodii strain was isolated from copper-containing coupons incubated in surface seawater (Key West, FL, USA). In addition to the original isolate, a copper-adapted mutant was created and maintained with 0.78 mM Cu2+. Biofilm formation was compared between the two strains under copper-amended and low-nutrient conditions. Biofilm formation was significantly increased in the original isolate under copper amendment, while biofilm formation was significantly higher in the mutant under low-nutrient conditions. Biofilm expression profiles of diguanylate cyclase (DGC) genes, as well as genes involved in secretion, differed between the strains. Comparative genomic analysis demonstrated that both strains possessed a large number of gene attachment harboring cyclic di-GMP synthesis and/or degradation domains. One of the DGC genes, induced at very high levels in the mutant, possessed a degradation domain in the original isolate that was lacking in the mutant. The genetic and transcriptional mechanisms contributing to biofilm formation are discussed.
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Affiliation(s)
- Kathleen D Cusick
- a Chemistry Department , US Naval Research Laboratory , Washington , DC , USA
| | - Jason R Dale
- b Geosciences Division , US Naval Research Laboratory, Stennis Space Center , Mississippi , MS , USA
| | - Lisa A Fitzgerald
- c Chemistry Department , US Naval Research Laboratory , Washington , DC , USA
| | - Brenda J Little
- b Geosciences Division , US Naval Research Laboratory, Stennis Space Center , Mississippi , MS , USA
| | - Justin C Biffinger
- c Chemistry Department , US Naval Research Laboratory , Washington , DC , USA
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8
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Unoarumhi Y, Blumenthal RM, Matson JS. Evolution of a global regulator: Lrp in four orders of γ-Proteobacteria. BMC Evol Biol 2016; 16:111. [PMID: 27206730 PMCID: PMC4875751 DOI: 10.1186/s12862-016-0685-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/12/2016] [Indexed: 11/11/2022] Open
Abstract
Background Bacterial global regulators each regulate the expression of several hundred genes. In Escherichia coli, the top seven global regulators together control over half of all genes. Leucine-responsive regulatory protein (Lrp) is one of these top seven global regulators. Lrp orthologs are very widely distributed, among both Bacteria and Archaea. Surprisingly, even within the phylum γ-Proteobacteria (which includes E. coli), Lrp is a global regulator in some orders and a local regulator in others. This raises questions about the evolution of Lrp and, more broadly, of global regulators. Results We examined Lrp sequences from four bacterial orders of the γ-Proteobacteria using phylogenetic and Logo analyses. The orders studied were Enterobacteriales and Vibrionales, in which Lrp plays a global role in tested species; Pasteurellales, in which Lrp is a local regulator in the tested species; and Alteromonadales, an order closely related to the other three but in which Lrp has not yet been studied. For comparison, we analyzed the Lrp paralog AsnC, which in all tested cases is a local regulator. The Lrp and AsnC phylogenetic clusters each divided, as expected, into subclusters representing the Enterobacteriales, Vibrionales, and Pasteuralles. However the Alteromonadales did not yield coherent clusters for either Lrp or AsnC. Logo analysis revealed signatures associated with globally- vs. locally- acting Lrp orthologs, providing testable hypotheses for which portions of Lrp are responsible for a global vs. local role. These candidate regions include both ends of the Lrp polypeptide but not, interestingly, the highly-conserved helix-turn-helix motif responsible for DNA sequence specificity. Conclusions Lrp and AsnC have conserved sequence signatures that allow their unambiguous annotation, at least in γ-Proteobacteria. Among Lrp orthologs, specific residues correlated with global vs. local regulatory roles, and can now be tested to determine which are functionally relevant and which simply reflect divergence. In the Alteromonadales, it appears that there are different subgroups of Lrp orthologs, one of which may act globally while the other may act locally. These results suggest experiments to improve our understanding of the evolution of bacterial global regulators. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0685-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yvette Unoarumhi
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA.,Program in Bioinformatics and Proteomics/Genomics, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Robert M Blumenthal
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA.,Program in Bioinformatics and Proteomics/Genomics, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Jyl S Matson
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA.
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9
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Payne SM, Mey AR, Wyckoff EE. Vibrio Iron Transport: Evolutionary Adaptation to Life in Multiple Environments. Microbiol Mol Biol Rev 2016; 80:69-90. [PMID: 26658001 PMCID: PMC4711184 DOI: 10.1128/mmbr.00046-15] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Iron is an essential element for Vibrio spp., but the acquisition of iron is complicated by its tendency to form insoluble ferric complexes in nature and its association with high-affinity iron-binding proteins in the host. Vibrios occupy a variety of different niches, and each of these niches presents particular challenges for acquiring sufficient iron. Vibrio species have evolved a wide array of iron transport systems that allow the bacteria to compete for this essential element in each of its habitats. These systems include the secretion and uptake of high-affinity iron-binding compounds (siderophores) as well as transport systems for iron bound to host complexes. Transporters for ferric and ferrous iron not complexed to siderophores are also common to Vibrio species. Some of the genes encoding these systems show evidence of horizontal transmission, and the ability to acquire and incorporate additional iron transport systems may have allowed Vibrio species to more rapidly adapt to new environmental niches. While too little iron prevents growth of the bacteria, too much can be lethal. The appropriate balance is maintained in vibrios through complex regulatory networks involving transcriptional repressors and activators and small RNAs (sRNAs) that act posttranscriptionally. Examination of the number and variety of iron transport systems found in Vibrio spp. offers insights into how this group of bacteria has adapted to such a wide range of habitats.
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Affiliation(s)
- Shelley M Payne
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Alexandra R Mey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Elizabeth E Wyckoff
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
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10
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All Three TonB Systems Are Required for Vibrio vulnificus CMCP6 Tissue Invasiveness by Controlling Flagellum Expression. Infect Immun 2015; 84:254-65. [PMID: 26527216 DOI: 10.1128/iai.00821-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/24/2015] [Indexed: 01/22/2023] Open
Abstract
TonB systems actively transport iron-bound substrates across the outer membranes of Gram-negative bacteria. Vibrio vulnificus CMCP6, which causes fatal septicemia and necrotizing wound infections, possesses three active TonB systems. It is not known why V. vulnificus CMCP6 has maintained three TonB systems throughout its evolution. The TonB1 and TonB2 systems are relatively well characterized, while the pathophysiological function of the TonB3 system is still elusive. A reverse transcription-PCR (RT-PCR) study showed that the tonB1 and tonB2 genes are preferentially induced in vivo, whereas tonB3 is persistently transcribed, albeit at low expression levels, under both in vitro and in vivo conditions. The goal of the present study was to elucidate the raison d'être of these three TonB systems. In contrast to previous studies, we constructed in-frame single-, double-, and triple-deletion mutants of the entire structural genes in TonB loci, and the changes in various virulence-related phenotypes were evaluated. Surprisingly, only the tonB123 mutant exhibited a significant delay in killing eukaryotic cells, which was complemented in trans with any TonB operon. Very interestingly, we discovered that flagellum biogenesis was defective in the tonB123 mutant. The loss of flagellation contributed to severe defects in motility and adhesion of the mutant. Because of the difficulty of making contact with host cells, the mutant manifested defective RtxA1 toxin production, which resulted in impaired invasiveness, delayed cytotoxicity, and decreased lethality for mice. Taken together, these results indicate that a series of virulence defects in all three TonB systems of V. vulnificus CMCP6 coordinately complement each other for iron assimilation and full virulence expression by ensuring flagellar biogenesis.
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11
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León-Sicairos N, Angulo-Zamudio UA, de la Garza M, Velázquez-Román J, Flores-Villaseñor HM, Canizalez-Román A. Strategies of Vibrio parahaemolyticus to acquire nutritional iron during host colonization. Front Microbiol 2015. [PMID: 26217331 PMCID: PMC4496571 DOI: 10.3389/fmicb.2015.00702] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Iron is an essential element for the growth and development of virtually all living organisms. As iron acquisition is critical for the pathogenesis, a host defense strategy during infection is to sequester iron to restrict the growth of invading pathogens. To counteract this strategy, bacteria such as Vibrio parahaemolyticus have adapted to such an environment by developing mechanisms to obtain iron from human hosts. This review focuses on the multiple strategies employed by V. parahaemolyticus to obtain nutritional iron from host sources. In these strategies are included the use of siderophores and xenosiderophores, proteases and iron-protein receptor. The host sources used by V. parahaemolyticus are the iron-containing proteins transferrin, hemoglobin, and hemin. The implications of iron acquisition systems in the virulence of V. parahaemolyticus are also discussed.
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Affiliation(s)
- Nidia León-Sicairos
- Unidad de Investigación, Facultad de Medicina, Universidad Autónoma de Sinaloa Culiacán, Mexico ; Departamento de Investigación, Hospital Pediátrico de Sinaloa "Dr. Rigoberto Aguilar Pico" Culiacán, Mexico
| | - Uriel A Angulo-Zamudio
- Maestría en Ciencias de la Salud, Facultad de Medicina, Universidad Autónoma de Sinaloa Culiacán, Mexico
| | - Mireya de la Garza
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Mexico, Mexico
| | - Jorge Velázquez-Román
- Unidad de Investigación, Facultad de Medicina, Universidad Autónoma de Sinaloa Culiacán, Mexico
| | | | - Adrian Canizalez-Román
- Unidad de Investigación, Facultad de Medicina, Universidad Autónoma de Sinaloa Culiacán, Mexico
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12
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Amaral GRS, Dias GM, Wellington-Oguri M, Chimetto L, Campeão ME, Thompson FL, Thompson CC. Genotype to phenotype: identification of diagnostic vibrio phenotypes using whole genome sequences. Int J Syst Evol Microbiol 2014; 64:357-365. [PMID: 24505074 DOI: 10.1099/ijs.0.057927-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vibrios are ubiquitous in the aquatic environment and can be found in association with animal or plant hosts. The range of ecological relationships includes pathogenic and mutualistic associations. To gain a better understanding of the ecology of these microbes, it is important to determine their phenotypic features. However, the traditional phenotypic characterization of vibrios has been expensive, time-consuming and restricted in scope to a limited number of features. In addition, most of the commercial systems applied for phenotypic characterization cannot characterize the broad spectrum of environmental strains. A reliable and possible alternative is to obtain phenotypic information directly from whole genome sequences. The aim of the present study was to evaluate the usefulness of whole genome sequences as a source of phenotypic information. We performed a comparison of the vibrio phenotypes obtained from the literature with the phenotypes obtained from whole genome sequences. We observed a significant correlation between the previously published phenotypic data and the phenotypic data retrieved from whole genome sequences of vibrios. Analysis of 26 vibrio genomes revealed that all genes coding for the specific proteins involved in the metabolic pathways responsible for positive phenotypes of the 14 diagnostic features (Voges-Proskauer reaction, indole production, arginine dihydrolase, ornithine decarboxylase, utilization of myo-inositol, sucrose and L-leucine, and fermentation of D-mannitol, D-sorbitol, L-arabinose, trehalose, cellobiose, D-mannose and D-galactose) were found in the majority of the vibrios genomes. Vibrio species that were negative for a given phenotype revealed the absence of all or several genes involved in the respective biochemical pathways, indicating the utility of this approach to characterize the phenotypes of vibrios. The absence of the global regulation and regulatory proteins in the Vibrio parahaemolyticus genome indicated a non-vibrio phenotype. Whole genome sequences represent an important source for the phenotypic identification of vibrios.
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Affiliation(s)
| | - Graciela M Dias
- Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Brazil
| | | | - Luciane Chimetto
- Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Brazil
| | - Mariana E Campeão
- Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Brazil
| | - Fabiano L Thompson
- Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Brazil
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13
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Kim YR, Lee SE, Kim B, Choy H, Rhee JH. A dual regulatory role of cyclic adenosine monophosphate receptor protein in various virulence traits of Vibrio vulnificus. Microbiol Immunol 2013; 57:273-80. [PMID: 23586631 DOI: 10.1111/1348-0421.12031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 01/24/2013] [Accepted: 01/26/2013] [Indexed: 12/01/2022]
Abstract
Vibrio vulnificus causes fatal septicemia in susceptible subjects after the ingestion of raw seafood. In the present study, the roles of cyclic adenosine monophosphate (cAMP) receptor protein (CRP) in V. vulnificus pathogenesis were investigated. A mutation in the V. vulnificus crp gene resulted in a significant down-regulation of various virulence phenotypes, except for RtxA1-mediated cytoskeletal rearrangement. Bacterial growth was impeded by the crp mutation. In addition, colony morphology was converted from opaque to translucent type by this mutation, which implies a decrease in capsule production. The crp mutant also showed significant decrease in motility and adhesion to host cells. V. vulnificus CRP positively regulated production of hemolysin and protease at transcriptional level. All these changes in the crp mutant were fully complemented in trans by a plasmid harboring the wild-type gene. In contrast, CRP negatively regulated the expression of RtxA1. The crp mutant caused the cytoskeletal rearrangement in HeLa cells, which is a hallmark activity of RtxA1 toxin. Taken together, CRP seems to play a dual regulatory role in various virulence traits of V. vulnificus.
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Affiliation(s)
- Young Ran Kim
- Clinical Vaccine Research and Development Center, Chonnam National University Medical School, Gwangju, South Korea
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