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Gonyar LA, Sauder AB, Mortensen L, Willsey GG, Kendall MM. The yad and yeh fimbrial loci influence gene expression and virulence in enterohemorrhagic Escherichia coli O157:H7. mSphere 2024; 9:e0012424. [PMID: 38904402 PMCID: PMC11287998 DOI: 10.1128/msphere.00124-24] [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: 02/15/2024] [Accepted: 05/15/2024] [Indexed: 06/22/2024] Open
Abstract
Fimbriae are essential virulence factors for many bacterial pathogens. Fimbriae are extracellular structures that attach bacteria to surfaces. Thus, fimbriae mediate a critical step required for any pathogen to establish infection by anchoring a bacterium to host tissue. The human pathogen enterohemorrhagic Escherichia coli (EHEC) O157:H7encodes 16 fimbriae that may be important for EHEC to initiate infection and allow for productive expression of virulence traits important in later stages of infection, including a type III secretion system (T3SS) and Shiga toxin; however, the roles of most EHEC fimbriae are largely uncharacterized. Here, we provide evidence that two EHEC fimbriae, Yad and Yeh, modulate expression of diverse genes including genes encoding T3SS and Shiga toxin and that these fimbriae are required for robust colonization of the gastrointestinal tract. These findings reveal a significant and previously unappreciated role for fimbriae in bacterial pathogenesis as important determinants of virulence gene expression.IMPORTANCEFimbriae are extracellular proteinaceous structures whose defining role is to anchor bacteria to surfaces. This is a fundamental step for bacterial pathogens to establish infection in a host. Here, we show that the contributions of fimbriae to pathogenesis are more complex. Specifically, we demonstrate that fimbriae influence expression of virulence traits essential for disease progression in the intestinal pathogen enterohemorrhagic Escherichia coli. Gram-positive and Gram-negative bacteria express multiple fimbriae; therefore, these findings may have broad implications for understanding how pathogens use fimbriae, beyond adhesion, to initiate infection and coordinate gene expression, which ultimately results in disease.
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Affiliation(s)
- Laura A. Gonyar
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Amber B. Sauder
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Lindsay Mortensen
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Graham G. Willsey
- Department of Microbiology and Molecular Genetics, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Melissa M. Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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2
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Jaramillo-Jaramillo AS, Blanvillain-Rivera V, Coulson TJD, Farzan V, Friendship R, Labbe A. Effect of a Lactococcus lactis culture supernatant on diarrhea and performance parameters of piglets in the post-weaning period and on expression of the faeG gene in vitro. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2024; 65:259-266. [PMID: 38434158 PMCID: PMC10880393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Objectives To evaluate the effects of a cell-free supernatant from Lactococcus lactis (CFSM) on performance and diarrhearelated parameters and the presence of F4+ enterotoxigenic E. coli (ETEC) in piglets during post-weaning, and to evaluate the in vitro effect of the CFSM on faeG gene expression in an E. coli F4+. Animals and procedure In 3 trials with 90 piglets per trial, pigs were assigned to receive a placebo or 1 of 2 CFSM treatments and observed for diarrhea and performance. Fecal swabs were taken to determine the presence of ETEC. Quantitative RT-PCR was used to assess faeG gene expression in E. coli 21259 after treatment with CFSM at 50 mg/mL. Results The CFSM administered for 14 d at a dose of 24 mg/kg BW (2X) reduced diarrhea-related parameters compared to the placebo. Quantitative RT-PCR showed that, in E. coli 21259 treated with CFSM at 50 mg/mL, expression of the faeG gene was significantly repressed (P < 0.0001) relative to that in the untreated control. Conclusion The evaluated CFSM reduced the frequency and prevalence of diarrhea in a field situation. The in vitro treatment had an inhibitory effect on the expression of the faeG gene in F4+ E. coli 21259.
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Affiliation(s)
- Ana Sophia Jaramillo-Jaramillo
- MicroSintesis, 797 Victoria Road, Victoria, Prince Edward Island C0A 2G0 (Jaramillo-Jaramillo, Blanvillain-Rivera, Coulson, Labbe); Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Farzan, Friendship)
| | - Virginie Blanvillain-Rivera
- MicroSintesis, 797 Victoria Road, Victoria, Prince Edward Island C0A 2G0 (Jaramillo-Jaramillo, Blanvillain-Rivera, Coulson, Labbe); Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Farzan, Friendship)
| | - Thomas J D Coulson
- MicroSintesis, 797 Victoria Road, Victoria, Prince Edward Island C0A 2G0 (Jaramillo-Jaramillo, Blanvillain-Rivera, Coulson, Labbe); Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Farzan, Friendship)
| | - Vahab Farzan
- MicroSintesis, 797 Victoria Road, Victoria, Prince Edward Island C0A 2G0 (Jaramillo-Jaramillo, Blanvillain-Rivera, Coulson, Labbe); Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Farzan, Friendship)
| | - Robert Friendship
- MicroSintesis, 797 Victoria Road, Victoria, Prince Edward Island C0A 2G0 (Jaramillo-Jaramillo, Blanvillain-Rivera, Coulson, Labbe); Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Farzan, Friendship)
| | - Alain Labbe
- MicroSintesis, 797 Victoria Road, Victoria, Prince Edward Island C0A 2G0 (Jaramillo-Jaramillo, Blanvillain-Rivera, Coulson, Labbe); Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1 (Farzan, Friendship)
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3
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Akouris PP, Stuivenberg GA, Chmiel JA, Kiattiburut W, Poon A, Reid G, Burton JP. Ethanolamine enhances adhesion, promotes microcompartment formation, and modulates gene expression in Levilactobacillus brevis ATCC 14869. Gut Microbes 2024; 16:2350778. [PMID: 38717446 PMCID: PMC11086012 DOI: 10.1080/19490976.2024.2350778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 04/29/2024] [Indexed: 05/12/2024] Open
Abstract
Ethanolamine is an abundant compound in the gastrointestinal tract and a valuable source of carbon and nitrogen for pathogenic bacteria harboring ethanolamine utilization (eut) genes. Eut-positive pathogens can consume free ethanolamine to outcompete commensal microbes, which often lack eut genes, and establish infection. Ethanolamine can also act as a host recognition signal for eut-positive pathogens to upregulate virulence genes during colonization. Therefore, reducing free ethanolamine titers may represent a novel approach to preventing infection by eut-positive pathogens. Interestingly, the commensal microorganism Levilactobacillus brevis ATCC 14869 was found to encode over 18 eut genes within its genome. This led us to hypothesize that L. brevis can compete with eut-positive pathogens by clearing free ethanolamine from the environment. Our results demonstrate that despite being unable to metabolize ethanolamine under most conditions, L. brevis ATCC 14869 responds to the compound by increasing the expression of genes encoding proteins involved in microcompartment formation and adhesion to the intestinal epithelial barrier. The improved intestinal adhesion of L. brevis in the presence of ethanolamine also enhanced the exclusion of eut-positive pathogens from adhering to intestinal epithelial cells. These findings support further studies to test whether L. brevis ATCC 14869 can counter enteric pathogens and prevent or reduce the severity of infections. Overall, the metabolic capabilities of L. brevis ATCC 14869 offer a unique opportunity to add to the armamentarium of antimicrobial therapies as well as our understanding of the mechanisms used by beneficial microbes to sense and adapt to host microenvironments.
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Affiliation(s)
- Polycronis P. Akouris
- Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Canadian Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London, ON, Canada
| | - Gerrit A. Stuivenberg
- Canadian Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London, ON, Canada
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - John A. Chmiel
- Canadian Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London, ON, Canada
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Wongsakorn Kiattiburut
- Canadian Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London, ON, Canada
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Annabel Poon
- Canadian Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London, ON, Canada
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Gregor Reid
- Canadian Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London, ON, Canada
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Jeremy P. Burton
- Canadian Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London, ON, Canada
- Department of Microbiology and Immunology, Western University, London, ON, Canada
- Department of Surgery, Division of Urology, Western University, London, ON, Canada
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Moreira de Gouveia MI, Daniel J, Garrivier A, Bernalier-Donadille A, Jubelin G. Diversity of ethanolamine utilization by human commensal Escherichiacoli. Res Microbiol 2023; 174:103989. [PMID: 35988812 DOI: 10.1016/j.resmic.2022.103989] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 01/11/2023]
Abstract
Ethanolamine (EA) is a substrate naturally present in the human gut and its catabolism by bacteria relies on the presence of eut genes encoding specific metabolic enzymes and accessory proteins. To date, EA utilization has been mostly investigated in gut bacterial pathogens. The aim of this study was to evaluate the ability of human gut commensal Escherichia coli isolates to utilize EA as a nitrogen and/or carbon sources. Although the capacity to consume EA is heterogeneous between the 40 strains of our collection, we determined that most of them could degrade EA to generate ammonia, a useful nitrogen resource for growth. Three isolates were also able to exploit EA as a carbon source. We also revealed that the inability of some strains to catabolize EA is explained either by mutations in the eut locus or by a defect in gene transcription. Finally, we demonstrated the importance of EA utilization for an optimal fitness of commensal E. coli in vivo. Our study provides new insights on the diversity of commensal E. coli strains to utilize EA as a nutrient in the gut and opens the way for new research in the field of interactions between host, gut microbiota and pathogens.
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Affiliation(s)
| | - Julien Daniel
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France.
| | - Annie Garrivier
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France.
| | | | - Gregory Jubelin
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France.
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5
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Strain R, Stanton C, Ross RP. Effect of diet on pathogen performance in the microbiome. MICROBIOME RESEARCH REPORTS 2022; 1:13. [PMID: 38045644 PMCID: PMC10688830 DOI: 10.20517/mrr.2021.10] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/17/2022] [Accepted: 02/23/2022] [Indexed: 12/05/2023]
Abstract
Intricate interactions among commensal bacteria, dietary substrates and immune responses are central to defining microbiome community composition, which plays a key role in preventing enteric pathogen infection, a dynamic phenomenon referred to as colonisation resistance. However, the impact of diet on sculpting microbiota membership, and ultimately colonisation resistance has been overlooked. Furthermore, pathogens have evolved strategies to evade colonisation resistance and outcompete commensal microbiota by using unique nutrient utilisation pathways, by exploiting microbial metabolites as nutrient sources or by environmental cues to induce virulence gene expression. In this review, we will discuss the interplay between diet, microbiota and their associated metabolites, and how these can contribute to or preclude pathogen survival.
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Affiliation(s)
- Ronan Strain
- APC Microbiome Ireland, Biosciences Institute, University College Cork, Cork T12 YT20, Ireland
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork P61 C996, Ireland
| | - Catherine Stanton
- APC Microbiome Ireland, Biosciences Institute, University College Cork, Cork T12 YT20, Ireland
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork P61 C996, Ireland
| | - R. Paul Ross
- APC Microbiome Ireland, Biosciences Institute, University College Cork, Cork T12 YT20, Ireland
- School of Microbiology, University College Cork, College Road, Cork T12 K8AF, Ireland
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Garofalo L, Nakama C, Hanes D, Zwickey H. Whole-Person, Urobiome-Centric Therapy for Uncomplicated Urinary Tract Infection. Antibiotics (Basel) 2022; 11:218. [PMID: 35203820 PMCID: PMC8868435 DOI: 10.3390/antibiotics11020218] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 02/04/2023] Open
Abstract
A healthy urinary tract contains a variety of microbes resulting in a diverse urobiome. Urobiome dysbiosis, defined as an imbalance in the microbial composition in the microenvironments along the urinary tract, is found in women with uncomplicated urinary tract infection (UTI). Historically, antibiotics have been used to address UTI. An alternative approach to uncomplicated UTI is warranted as the current paradigm fails to take urobiome dysbiosis into account and contributes to the communal problem of resistance. A whole-person, multi-modal approach that addresses vaginal and urinary tract dysbiosis may be more effective in reducing recurrent UTI. In this review, we discuss strategies that include reducing pathogenic bacteria while supporting commensal urogenital bacteria, encouraging diuresis, maintaining optimal pH levels, and reducing inflammation. Strategies for future research are suggested.
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Affiliation(s)
- Luciano Garofalo
- Department of Child, Family, and Population Health Nursing, University of Washington, Seattle, WA 98195, USA
| | - Claudia Nakama
- National University of Natural Medicine, Portland, OR 97201, USA; (C.N.); (D.H.); (H.Z.)
| | - Douglas Hanes
- National University of Natural Medicine, Portland, OR 97201, USA; (C.N.); (D.H.); (H.Z.)
- Helfgott Research Institute, NUNM, Portland, OR 97201, USA
| | - Heather Zwickey
- National University of Natural Medicine, Portland, OR 97201, USA; (C.N.); (D.H.); (H.Z.)
- Helfgott Research Institute, NUNM, Portland, OR 97201, USA
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7
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Sharma VK, Akavaram S, Bayles DO. Genomewide transcriptional response of Escherichia coli O157:H7 to norepinephrine. BMC Genomics 2022; 23:107. [PMID: 35135480 PMCID: PMC8822769 DOI: 10.1186/s12864-021-08167-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/10/2021] [Indexed: 01/18/2023] Open
Abstract
Background Chemical signaling between a mammalian host and intestinal microbes is health and maintenance of ‘healthy’ intestinal microbiota. Escherichia coli O157:H7 can hijack host- and microbiota-produced chemical signals for survival in a harsh and nutritionally competitive gastrointestinal environment and for intestinal colonization. Norepinephrine (NE) produced by sympathetic neurons of the enteric nervous system has been shown in vitro to induce expression of genes controlling E. coli O157:H7 swimming motility, acid resistance, and adherence to epithelial cells. A previous study used a microarray approach to identify differentially expressed genes in E. coli O157:H7 strain EDL933 in response to NE. To elucidate a comprehensive transcriptional response to NE, we performed RNA-Seq on rRNA-depleted RNA of E. coli O157:H7 strain NADC 6564, an isolate of a foodborne E. coli O157:H7 strain 86–24. The reads generated by RNA-Seq were mapped to NADC 6564 genome using HiSat2. The mapped reads were quantified by htseq-count against the genome of strain NADC 6564. The differentially expressed genes were identified by analyzing quantified reads by DESeq2. Results Of the 585 differentially expressed genes (≥ 2.0-fold; p < 0.05), many encoded pathways promoting ability of E. coli O157:H7 strain NADC 6564 to colonize intestines of carrier animals and to produce disease in an incidental human host through increased adherence to epithelial cells and production of Shiga toxins. In addition, NE exposure also induced the expression of genes encoding pathways conferring prolonged survival at extreme acidity, controlling influx/efflux of specific nutrients/metabolites, and modulating tolerance to various stressors. A correlation was also observed between the EvgS/EvgA signal transduction system and the ability of bacterial cells to survive exposure to high acidity for several hours. Many genes involved in nitrogen, sulfur, and amino acid uptake were upregulated while genes linked to iron (Fe3+) acquisition and transport were downregulated. Conclusion The availability of physiological levels of NE in gastrointestinal tract could serve as an important cue for E. coli O157:H7 to engineer its virulence, stress, and metabolic pathways for colonization in reservoir animals, such as cattle, causing illness in humans, and surviving outside of a host. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08167-z.
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Affiliation(s)
- Vijay K Sharma
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, 50010, USA.
| | - Suryatej Akavaram
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, 50010, USA.,Current address: 4302 TX-332, Freeport, TX, 77541, USA
| | - Darrell O Bayles
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, 50010, USA
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8
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Sauder AB, Kendall MM. A pathogen-specific sRNA influences enterohemorrhagic Escherichia coli fitness and virulence in part by direct interaction with the transcript encoding the ethanolamine utilization regulatory factor EutR. Nucleic Acids Res 2021; 49:10988-11004. [PMID: 34591974 PMCID: PMC8565329 DOI: 10.1093/nar/gkab863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 01/07/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 relies on sRNAs to coordinate expression of metabolic and virulence factors to colonize the host. Here, we focus on the sRNA, named MavR (metabolism and virulence regulator), that is conserved among pathogenic Enterobacteriaceae. MavR is constitutively expressed under in vitro conditions that promote EHEC virulence gene expression. Using MS2-affinity purification coupled with RNA sequencing, the eutR transcript was identified as a putative target of MavR. EutR is a transcription factor that promotes expression of genes required for ethanolamine metabolism as well as virulence factors important for host colonization. MavR binds to the eutR coding sequence to protect the eutR transcript from RNase E-mediated degradation. Ultimately, MavR promotes EutR expression and in turn ethanolamine utilization and ethanolamine-dependent growth. RNAseq analyses revealed that MavR also affected expression of genes important for other metabolic pathways, motility, oxidative stress and attaching and effacing lesion formation, which contribute to EHEC colonization of the gastrointestinal tract. In support of the idea that MavR-dependent gene expression affects fitness during infection, deletion of mavR resulted in significant (∼10- to 100-fold) attenuation in colonization of the mammalian intestine. Altogether, these studies reveal an important, extensive, and robust phenotype for a bacterial sRNA in host-pathogen interactions.
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Affiliation(s)
- Amber B Sauder
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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9
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Prentice MB. Bacterial microcompartments and their role in pathogenicity. Curr Opin Microbiol 2021; 63:19-28. [PMID: 34107380 DOI: 10.1016/j.mib.2021.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 04/26/2021] [Accepted: 05/17/2021] [Indexed: 02/08/2023]
Abstract
Catabolic bacterial microcompartments (BMC), or metabolosomes, are self-assembling structures formed by enzymes enclosed by porous protein shells. They provide a specialised environment inside bacterial cells separating a short catabolic pathway with reactive or toxic intermediates from the cytoplasm. Substrates for microcompartment metabolism like ethanolamine and 1,2-propanediol are constantly produced in the human intestine by bacterial metabolism of food or host cell components. Enteric pathogens gain a competitive advantage in the intestine by metabolising these substrates, an advantage enhanced by the host inflammatory response. They exploit the intestinal specificity of signature metabolosome substrates by adopting substrate sensors and regulators encoded by BMC operons for governance of non-metabolic processes in pathogenesis. In turn, products of microcompartment metabolism regulate the host immune system.
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Affiliation(s)
- Michael B Prentice
- Department of Pathology, University College Cork, Cork, Ireland; School of Microbiology, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland.
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10
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Engevik MA, Danhof HA, Auchtung J, Endres BT, Ruan W, Bassères E, Engevik AC, Wu Q, Nicholson M, Luna RA, Garey KW, Crawford SE, Estes MK, Lux R, Yacyshyn MB, Yacyshyn B, Savidge T, Britton RA, Versalovic J. Fusobacteriumnucleatum Adheres to Clostridioides difficile via the RadD Adhesin to Enhance Biofilm Formation in Intestinal Mucus. Gastroenterology 2021; 160:1301-1314.e8. [PMID: 33227279 PMCID: PMC7956072 DOI: 10.1053/j.gastro.2020.11.034] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/02/2020] [Accepted: 11/13/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND & AIMS Although Clostridioides difficile infection (CDI) is known to involve the disruption of the gut microbiota, little is understood regarding how mucus-associated microbes interact with C difficile. We hypothesized that select mucus-associated bacteria would promote C difficile colonization and biofilm formation. METHODS To create a model of the human intestinal mucus layer and gut microbiota, we used bioreactors inoculated with healthy human feces, treated with clindamycin and infected with C difficile with the addition of human MUC2-coated coverslips. RESULTS C difficile was found to colonize and form biofilms on MUC2-coated coverslips, and 16S rRNA sequencing showed a unique biofilm profile with substantial cocolonization with Fusobacterium species. Consistent with our bioreactor data, publicly available data sets and patient stool samples showed that a subset of patients with C difficile infection harbored high levels of Fusobacterium species. We observed colocalization of C difficile and F nucleatum in an aggregation assay using adult patients and stool of pediatric patients with inflammatory bowel disease and in tissue sections of patients with CDI. C difficile strains were found to coaggregate with F nucleatum subspecies in vitro; an effect that was inhibited by blocking or mutating the adhesin RadD on Fusobacterium and removal of flagella on C difficile. Aggregation was shown to be unique between F nucleatum and C difficile, because other gut commensals did not aggregate with C difficile. Addition of F nucleatum also enhanced C difficile biofilm formation and extracellular polysaccharide production. CONCLUSIONS Collectively, these data show a unique interaction of between pathogenic C difficile and F nucleatum in the intestinal mucus layer.
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Affiliation(s)
- Melinda A. Engevik
- Department of Pathology & Immunology, Baylor College of
Medicine,Texas Children’s Microbiome Center, Department of
Pathology, Texas Children's Hospital
| | - Heather A. Danhof
- Department of Molecular Virology and Microbiology, Baylor
College of Medicine
| | - Jennifer Auchtung
- Department of Molecular Virology and Microbiology, Baylor
College of Medicine,Department of Food Science and Technology, University of
Nebraska-Lincoln
| | - Bradley T. Endres
- Department of Pharmacy Practice and Translational Research,
University of Houston College of Pharmacy
| | - Wenly Ruan
- Department of Pathology & Immunology, Baylor College of
Medicine,Texas Children’s Microbiome Center, Department of
Pathology, Texas Children's Hospital
| | - Eugénie Bassères
- Department of Pharmacy Practice and Translational Research,
University of Houston College of Pharmacy
| | - Amy C. Engevik
- Department of Surgical Sciences, Vanderbilt University
Medical Center
| | - Qinglong Wu
- Department of Pathology & Immunology, Baylor College of
Medicine,Texas Children’s Microbiome Center, Department of
Pathology, Texas Children's Hospital
| | | | - Ruth Ann Luna
- Department of Pathology & Immunology, Baylor College of
Medicine,Texas Children’s Microbiome Center, Department of
Pathology, Texas Children's Hospital
| | - Kevin W. Garey
- Department of Pharmacy Practice and Translational Research,
University of Houston College of Pharmacy
| | - Sue E. Crawford
- Department of Molecular Virology and Microbiology, Baylor
College of Medicine
| | - Mary K. Estes
- Department of Molecular Virology and Microbiology, Baylor
College of Medicine,Department of Surgical Sciences, Vanderbilt University
Medical Center
| | - Renate Lux
- Department of Periodontics, University of California Los
Angeles School of Dentistry
| | - Mary Beth Yacyshyn
- Department of Medicine Division of Digestive Diseases
University of Cincinnati College of Medicine
| | - Bruce Yacyshyn
- Department of Medicine Division of Digestive Diseases
University of Cincinnati College of Medicine
| | - Tor Savidge
- Department of Pathology & Immunology, Baylor College of
Medicine,Texas Children’s Microbiome Center, Department of
Pathology, Texas Children's Hospital
| | - Robert A. Britton
- Department of Molecular Virology and Microbiology, Baylor
College of Medicine
| | - James Versalovic
- Department of Pathology & Immunology, Baylor College of
Medicine,Texas Children’s Microbiome Center, Department of
Pathology, Texas Children's Hospital
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11
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Straub TJ, Chou WC, Manson AL, Schreiber HL, Walker BJ, Desjardins CA, Chapman SB, Kaspar KL, Kahsai OJ, Traylor E, Dodson KW, Hullar MAJ, Hultgren SJ, Khoo C, Earl AM. Limited effects of long-term daily cranberry consumption on the gut microbiome in a placebo-controlled study of women with recurrent urinary tract infections. BMC Microbiol 2021; 21:53. [PMID: 33596852 PMCID: PMC7890861 DOI: 10.1186/s12866-021-02106-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/28/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Urinary tract infections (UTIs) affect 15 million women each year in the United States, with > 20% experiencing frequent recurrent UTIs. A recent placebo-controlled clinical trial found a 39% reduction in UTI symptoms among recurrent UTI sufferers who consumed a daily cranberry beverage for 24 weeks. Using metagenomic sequencing of stool from a subset of these trial participants, we assessed the impact of cranberry consumption on the gut microbiota, a reservoir for UTI-causing pathogens such as Escherichia coli, which causes > 80% of UTIs. RESULTS The overall taxonomic composition, community diversity, carriage of functional pathways and gene families, and relative abundances of the vast majority of observed bacterial taxa, including E. coli, were not changed significantly by cranberry consumption. However, one unnamed Flavonifractor species (OTU41), which represented ≤1% of the overall metagenome, was significantly less abundant in cranberry consumers compared to placebo at trial completion. Given Flavonifractor's association with negative human health effects, we sought to determine OTU41 characteristic genes that may explain its differential abundance and/or relationship to key host functions. Using comparative genomic and metagenomic techniques, we identified genes in OTU41 related to transport and metabolism of various compounds, including tryptophan and cobalamin, which have been shown to play roles in host-microbe interactions. CONCLUSION While our results indicated that cranberry juice consumption had little impact on global measures of the microbiome, we found one unnamed Flavonifractor species differed significantly between study arms. This suggests further studies are needed to assess the role of cranberry consumption and Flavonifractor in health and wellbeing in the context of recurrent UTI. TRIAL REGISTRATION Clinical trial registration number: ClinicalTrials.gov NCT01776021 .
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Affiliation(s)
- Timothy J Straub
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Wen-Chi Chou
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Abigail L Manson
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Henry L Schreiber
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Bruce J Walker
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Christopher A Desjardins
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Sinéad B Chapman
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | | | - Orsalem J Kahsai
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Elizabeth Traylor
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Karen W Dodson
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Meredith A J Hullar
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Scott J Hultgren
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | | | - Ashlee M Earl
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA.
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12
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Anast JM, Bobik TA, Schmitz-Esser S. The Cobalamin-Dependent Gene Cluster of Listeria monocytogenes: Implications for Virulence, Stress Response, and Food Safety. Front Microbiol 2020; 11:601816. [PMID: 33240255 PMCID: PMC7677406 DOI: 10.3389/fmicb.2020.601816] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/19/2020] [Indexed: 12/21/2022] Open
Abstract
Several genes of the eut, pdu, and cob/cbi operons are responsible for the metabolism of ethanolamine (EA) and 1,2-propanediol (PD) and are essential during the pathogenic lifecycles of various enteric pathogens. Studies concerning EA and PD metabolism have primarily focused on bacterial genera from the family Enterobacteriaceae, especially the genus Salmonella. Listeria monocytogenes is a member of the Firmicutes phylum and is the causative agent of the rare but highly fatal foodborne disease listeriosis. The eut, pdu, and cob/cbi operons are organized as a single large locus collectively referred to as the cobalamin-dependent gene cluster (CDGC). The CDGC is well conserved in L. monocytogenes; however, functional characterization of the genes in this cluster and how they may contribute to Listeria virulence and stress tolerance in food production environments is highly limited. Previous work suggests that the degradation pathway of PD is essential for L. monocytogenes establishment in the gastrointestinal tract. In contrast, EA metabolism may be more important during intracellular replication. Other studies indicate that the CDGC is utilized when L. monocytogenes is exposed to food and food production relevant stress conditions. Perhaps most noteworthy, L. monocytogenes exhibits attenuated growth at cold temperatures when a key EA utilization pathway gene was deleted. This review aims to summarize the current knowledge of these pathways in L. monocytogenes and their significance in virulence and stress tolerance, especially considering recent developments.
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Affiliation(s)
- Justin M Anast
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
| | - Thomas A Bobik
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Stephan Schmitz-Esser
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
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13
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Stromberg ZR, Masonbrink RE, Mellata M. Transcriptomic Analysis of Shiga Toxin-Producing Escherichia coli during Initial Contact with Cattle Colonic Explants. Microorganisms 2020; 8:E1662. [PMID: 33120988 PMCID: PMC7693793 DOI: 10.3390/microorganisms8111662] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 01/10/2023] Open
Abstract
Foodborne pathogens are a public health threat globally. Shiga toxin-producing Escherichia coli (STEC), particularly O26, O111, and O157 STEC, are often associated with foodborne illness in humans. To create effective preharvest interventions, it is critical to understand which factors STEC strains use to colonize the gastrointestinal tract of cattle, which serves as the reservoir for these pathogens. Several colonization factors are known, but little is understood about initial STEC colonization factors. Our objective was to identify these factors via contrasting gene expression between nonpathogenic E. coli and STEC. Colonic explants were inoculated with nonpathogenic E. coli strain MG1655 or STEC strains (O26, O111, or O157), bacterial colonization levels were determined, and RNA was isolated and sequenced. STEC strains adhered to colonic explants at numerically but not significantly higher levels compared to MG1655. After incubation with colonic explants, flagellin (fliC) was upregulated (log2 fold-change = 4.0, p < 0.0001) in O157 STEC, and collectively, Lon protease (lon) was upregulated (log2 fold-change = 3.6, p = 0.0009) in STEC strains compared to MG1655. These results demonstrate that H7 flagellum and Lon protease may play roles in early colonization and could be potential targets to reduce colonization in cattle.
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Affiliation(s)
- Zachary R. Stromberg
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA;
| | - Rick E. Masonbrink
- Genome Informatics Facility, Iowa State University, Ames, IA 50011, USA;
| | - Melha Mellata
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA;
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14
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The Ethanolamine-Sensing Transcription Factor EutR Promotes Virulence and Transmission during Citrobacter rodentium Intestinal Infection. Infect Immun 2020; 88:IAI.00137-20. [PMID: 32631916 DOI: 10.1128/iai.00137-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/26/2020] [Indexed: 12/18/2022] Open
Abstract
Enteric pathogens exploit chemical and nutrient signaling to gauge their location within a host and control expression of traits important for infection. Ethanolamine-containing molecules are essential in host physiology and play important roles in intestinal processes. The transcription factor EutR is conserved in the Enterobacteriaceae and is required for ethanolamine sensing and metabolism. In enterohemorrhagic Escherichia coli (EHEC) O157:H7, EutR responds to ethanolamine to activate expression of traits required for host colonization and disease; however, the importance of EutR to EHEC intestinal infection has not been examined. Because EHEC does not naturally colonize or cause disease in mice, we employed the natural murine pathogen Citrobacter rodentium as a model of EHEC virulence to investigate the importance of EutR in vivo EHEC and C. rodentium possess the locus of enterocyte effacement (LEE), which is the canonical virulence trait of attaching and effacing pathogens. Our findings demonstrate that ethanolamine sensing and EutR-dependent regulation of the LEE are conserved in C. rodentium Moreover, during infection, EutR is required for maximal LEE expression, colonization, and transmission efficiency. These findings reveal that EutR not only is important for persistence during the primary host infection cycle but also is required for maintenance in a host population.
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15
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Jimenez AG, Ellermann M, Abbott W, Sperandio V. Diet-derived galacturonic acid regulates virulence and intestinal colonization in enterohaemorrhagic Escherichia coli and Citrobacter rodentium. Nat Microbiol 2019; 5:368-378. [PMID: 31873206 PMCID: PMC6992478 DOI: 10.1038/s41564-019-0641-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022]
Abstract
Enteric pathogens sense the complex chemistry within the gastrointestinal (GI) tract to efficiently compete with the resident microbiota and establish a colonization niche. Here we show that enterohemorrhagic E. coli (EHEC), and its surrogate murine infection model Citrobacter rodentium, sense galacturonic-acid to initiate a multi-layered program towards successful mammalian infection. Galacturonic-acid utilization as a carbon source aids the initial pathogen expansion. The main source of galacturonic-acid is dietary pectin, which is broken into galacturonic-acid by the prominent member of the microbiota, Bacteroides thetaiotamicron (Bt). This regulation occurs through the ExuR transcription factor. However, galacturonic-acid is also sensed as a signal through ExuR to modulate the expression of the genes encoding a molecular syringe known as a type three secretion system (T3SS) leading to infectious colitis and inflammation. Galacturonic-acid moonlights as a nutrient and a signal directing the exquisite microbiota-pathogen relationships within the GI tract. Importantly, this work highlights that differential dietary sugar availability impacts the relationship between the microbiota and enteric pathogens, as well as disease outcomes.
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Affiliation(s)
- Angel G Jimenez
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Melissa Ellermann
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Wade Abbott
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada.,Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Vanessa Sperandio
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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16
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Kumar A, Ellermann M, Sperandio V. Taming the Beast: Interplay between Gut Small Molecules and Enteric Pathogens. Infect Immun 2019; 87:e00131-19. [PMID: 31262983 PMCID: PMC6704596 DOI: 10.1128/iai.00131-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The overuse of antibiotics has led to the evolution of drug-resistant bacteria that are becoming increasingly dangerous to human health. According to the Centers for Disease Control and Prevention, antibiotic-resistant bacteria cause at least 2 million illnesses and 23,000 deaths in the United States annually. Traditionally, antibiotics are bactericidal or bacteriostatic agents that place selective pressure on bacteria, leading to the expansion of antibiotic-resistant strains. In addition, antibiotics that are effective against some pathogens can also exacerbate their pathogenesis and may lead to severe progression of the disease. Therefore, alternative strategies are needed to treat antibiotic-resistant bacterial infections. One novel approach is to target bacterial virulence to prevent or limit pathogen colonization, while also minimizing tissue damage and disease comorbidities in the host. This review focuses on the interactions between enteric pathogens and naturally occurring small molecules in the human gut as potential therapeutic targets for antivirulence strategies. Individual small molecules in the intestines modulate enteric pathogen virulence and subsequent intestinal fitness and colonization. Targeted interruption of pathogen sensing of these small molecules could therefore attenuate their virulence. This review highlights the paths of discovery for new classes of antimicrobials that could potentially mitigate the urgent problem of antibiotic resistance.
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Affiliation(s)
- Aman Kumar
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Melissa Ellermann
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Vanessa Sperandio
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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17
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Metabolic adaptation of adherent-invasive Escherichia coli to exposure to bile salts. Sci Rep 2019; 9:2175. [PMID: 30778122 PMCID: PMC6379400 DOI: 10.1038/s41598-019-38628-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/13/2018] [Indexed: 12/12/2022] Open
Abstract
The adherent-invasive Escherichia coli (AIEC), which colonize the ileal mucosa of Crohn’s disease patients, adhere to intestinal epithelial cells, invade them and exacerbate intestinal inflammation. The high nutrient competition between the commensal microbiota and AIEC pathobiont requires the latter to occupy their own metabolic niches to survive and proliferate within the gut. In this study, a global RNA sequencing of AIEC strain LF82 has been used to observe the impact of bile salts on the expression of metabolic genes. The results showed a global up-regulation of genes involved in degradation and a down-regulation of those implicated in biosynthesis. The main up-regulated degradation pathways were ethanolamine, 1,2-propanediol and citrate utilization, as well as the methyl-citrate pathway. Our study reveals that ethanolamine utilization bestows a competitive advantage of AIEC strains that are metabolically capable of its degradation in the presence of bile salts. We observed that bile salts activated secondary metabolism pathways that communicate to provide an energy benefit to AIEC. Bile salts may be used by AIEC as an environmental signal to promote their colonization.
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18
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Chatterjee R, Shreenivas MM, Sunil R, Chakravortty D. Enteropathogens: Tuning Their Gene Expression for Hassle-Free Survival. Front Microbiol 2019; 9:3303. [PMID: 30687282 PMCID: PMC6338047 DOI: 10.3389/fmicb.2018.03303] [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: 09/26/2018] [Accepted: 12/19/2018] [Indexed: 12/27/2022] Open
Abstract
Enteropathogenic bacteria have been the cause of the majority of foodborne illnesses. Much of the research has been focused on elucidating the mechanisms by which these pathogens evade the host immune system. One of the ways in which they achieve the successful establishment of a niche in the gut microenvironment and survive is by a chain of elegantly regulated gene expression patterns. Studies have shown that this process is very elaborate and is also regulated by several factors. Pathogens like, enteropathogenic Escherichia coli (EPEC), Salmonella Typhimurium, Shigellaflexneri, Yersinia sp. have been seen to employ various regulated gene expression strategies. These include toxin-antitoxin systems, quorum sensing systems, expression controlled by nucleoid-associated proteins (NAPs), several regulons and operons specific to these pathogens. In the following review, we have tried to discuss the common gene regulatory systems of enteropathogenic bacteria as well as pathogen-specific regulatory mechanisms.
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Affiliation(s)
- Ritika Chatterjee
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India
| | - Meghanashree M Shreenivas
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India.,Undergraduate Studies, Indian Institute of Science, Bengaluru, India
| | - Rohith Sunil
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India.,Undergraduate Studies, Indian Institute of Science, Bengaluru, India
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India.,Centre for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, India
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19
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Rowley CA, Kendall MM. To B12 or not to B12: Five questions on the role of cobalamin in host-microbial interactions. PLoS Pathog 2019; 15:e1007479. [PMID: 30605490 PMCID: PMC6317780 DOI: 10.1371/journal.ppat.1007479] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Carol A. Rowley
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Melissa M. Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
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20
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Ethanolamine Influences Human Commensal Escherichia coli Growth, Gene Expression, and Competition with Enterohemorrhagic E. coli O157:H7. mBio 2018; 9:mBio.01429-18. [PMID: 30279284 PMCID: PMC6168858 DOI: 10.1128/mbio.01429-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The microbiota protects the host from invading pathogens by limiting access to nutrients. In turn, bacterial pathogens selectively exploit metabolites not readily used by the microbiota to establish infection. Ethanolamine has been linked to pathogenesis of diverse pathogens by serving as a noncompetitive metabolite that enhances pathogen growth as well as a signal that modulates virulence. Although ethanolamine is abundant in the gastrointestinal tract, the prevailing idea is that commensal bacteria do not utilize EA, and thus, EA utilization has been particularly associated with pathogenesis. Here, we provide evidence that two human commensal Escherichia coli isolates readily utilize ethanolamine to enhance growth, modulate gene expression, and outgrow the pathogen enterohemorrhagic E. coli. These data indicate a more complex role for ethanolamine in host-microbiota-pathogen interactions. A core principle of bacterial pathogenesis is that pathogens preferentially utilize metabolites that commensal bacteria do not in order to sidestep nutritional competition. The metabolite ethanolamine (EA) is well recognized to play a central role in host adaptation for diverse pathogens. EA promotes growth and influences virulence during host infection. Although genes encoding EA utilization have been identified in diverse bacteria (nonpathogenic and pathogenic), a prevailing idea is that commensal bacteria do not utilize EA to enhance growth, and thus, EA is a noncompetitive metabolite for pathogens. Here, we show that EA augments growth of two human commensal strains of Escherichia coli. Significantly, these commensal strains grow more rapidly than, and even outcompete, the pathogen enterohemorrhagic E. coli O157:H7 specifically when EA is provided as the sole nitrogen source. Moreover, EA-dependent signaling is similarly conserved in the human commensal E. coli strain HS and influences expression of adhesins. These findings suggest a more extensive role for EA utilization in bacterial physiology and host-microbiota-pathogen interactions than previously appreciated.
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21
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Pulmonary Surfactant Promotes Virulence Gene Expression and Biofilm Formation in Klebsiella pneumoniae. Infect Immun 2018; 86:IAI.00135-18. [PMID: 29712730 DOI: 10.1128/iai.00135-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/24/2018] [Indexed: 12/18/2022] Open
Abstract
The interactions between Klebsiella pneumoniae and the host environment at the site of infection are largely unknown. Pulmonary surfactant serves as an initial point of contact for inhaled bacteria entering the lung and is thought to contain molecular cues that aid colonization and pathogenesis. To gain insight into this ecological transition, we characterized the transcriptional response of K. pneumoniae MGH 78578 to purified pulmonary surfactant. This work revealed changes within the K. pneumoniae transcriptome that likely contribute to host colonization, adaptation, and virulence in vivo Notable transcripts expressed under these conditions include genes involved in capsule synthesis, lipopolysaccharide modification, antibiotic resistance, biofilm formation, and metabolism. In addition, we tested the contributions of other surfactant-induced transcripts to K. pneumoniae survival using engineered isogenic KPPR1 deletion strains in a murine model of acute pneumonia. In these infection studies, we identified the MdtJI polyamine efflux pump and the ProU glycine betaine ABC transporter to be significant mediators of K. pneumoniae survival within the lung and confirmed previous evidence for the importance of de novo leucine synthesis to bacterial survival during infection. Finally, we determined that pulmonary surfactant promoted type 3 fimbria-mediated biofilm formation in K. pneumoniae and identified two surfactant constituents, phosphatidylcholine and cholesterol, that drive this response. This study provides novel insight into the interactions occurring between K. pneumoniae and the host at an important infection site and demonstrates the utility of purified lung surfactant preparations for dissecting host-lung pathogen interactions in vitro.
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22
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A Bacterial Microcompartment Is Used for Choline Fermentation by Escherichia coli 536. J Bacteriol 2018; 200:JB.00764-17. [PMID: 29507086 DOI: 10.1128/jb.00764-17] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/23/2018] [Indexed: 01/16/2023] Open
Abstract
Bacterial choline degradation in the human gut has been associated with cancer and heart disease. In addition, recent studies found that a bacterial microcompartment is involved in choline utilization by Proteus and Desulfovibrio species. However, many aspects of this process have not been fully defined. Here, we investigate choline degradation by the uropathogen Escherichia coli 536. Growth studies indicated E. coli 536 degrades choline primarily by fermentation. Electron microscopy indicated that a bacterial microcompartment was used for this process. Bioinformatic analyses suggested that the choline utilization (cut) gene cluster of E. coli 536 includes two operons, one containing three genes and a main operon of 13 genes. Regulatory studies indicate that the cutX gene encodes a positive transcriptional regulator required for induction of the main cut operon in response to choline supplementation. Each of the 16 genes in the cut cluster was individually deleted, and phenotypes were examined. The cutX, cutY, cutF, cutO, cutC, cutD, cutU, and cutV genes were required for choline degradation, but the remaining genes of the cut cluster were not essential under the conditions used. The reasons for these varied phenotypes are discussed.IMPORTANCE Here, we investigate choline degradation in E. coli 536. These studies provide a basis for understanding a new type of bacterial microcompartment and may provide deeper insight into the link between choline degradation in the human gut and cancer and heart disease. These are also the first studies of choline degradation in E. coli 536, an organism for which sophisticated genetic analysis methods are available. In addition, the cut gene cluster of E. coli 536 is located in pathogenicity island II (PAI-II536) and hence might contribute to pathogenesis.
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23
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The Ethanolamine Permease EutH Promotes Vacuole Adaptation of Salmonella enterica and Listeria monocytogenes during Macrophage Infection. Infect Immun 2018. [PMID: 29531136 DOI: 10.1128/iai.00172-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Ethanolamine is a ubiquitous and essential molecule within a host. Significantly, bacterial pathogens exploit ethanolamine during infection to promote growth and regulate virulence. The ethanolamine permease EutH is dispensable for growth in vitro under standard conditions, whereas EutH is required for ethanolamine utilization at low pH. These findings suggested a model in which EutH facilitates diffusion of ethanolamine into the bacterial cell in acidic environments. To date, the ecological significance of this model has not been thoroughly investigated, and the importance of EutH to bacterial growth under physiologically relevant conditions is not known. During infection, immune cells internalize invading bacteria within an acidic, nutrient-depleted vacuole called the phagosome. Here, we investigated the hypothesis that EutH promotes bacterial survival following phagocytosis. Our findings indicate that EutH is important for survival and replication of the facultative intracellular pathogens Salmonella enterica serovar Typhimurium and Listeria monocytogenes during prolonged or transient exposure to the phagosome, respectively. Furthermore, in agreement with EutH being important in the acidic environment, neutralization of the vacuole abolished the requirement for EutH. Significantly, consistent with a role for EutH in promoting intramacrophage survival, EutH was not required during S Typhimurium local intestinal infection but specifically conferred an advantage upon dissemination to peripheral organs. These findings reveal a physiologically relevant and conserved role for EutH in spatiotemporal niche adaptation during infection.
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24
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Yagi H, Nakayama-Imaohji H, Nariya H, Tada A, Yamasaki H, Ugai H, Elahi M, Ono T, Kuwahara T. Ethanolamine utilization supports Clostridium perfringens growth in infected tissues. Microb Pathog 2018; 119:200-207. [PMID: 29654901 DOI: 10.1016/j.micpath.2018.04.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 01/07/2023]
Abstract
Clostridium perfringens possesses the ethanolamine (EA) utilization (eut) system encoded within the eut operon, which utilizes the EA as a carbon, nitrogen and energy source. To determine the role of the eut system in C. perfringens growth, an in-frame deletion of the eutABC genes was made in strain HN13 to generate the eutABC-deleted mutant strain HY1701. Comparison of HN13 and HY1701 growth in media supplemented with 1.0% glucose and/or 1.0% EA showed that glucose enhanced the growth of both strains, whereas EA enhanced HN13 growth, but not that of HY1701, indicating that the eut system is necessary for C. perfringens to utilize EA. The two-component regulatory system EutVW is needed to induce eut gene expression in response to EA whereas the global virulence regulator VirRS differentially controlled eut gene expression depending on glucose and EA availability. To assess the role of the eut system in vivo, an equal number of HN13 and HY1701 cells were injected into the right thigh muscles of mice. Mice infected with HY1701 showed fewer symptoms than those injected with HN13. The mortality rate of mice infected with HY1701 tended to be lower than for mice infected with HN13. In addition, in infected tissues from mice injected with a mixture of HN13 and HY1701, HN13 outnumbered HY1701. PCR screening demonstrated that C. perfringens isolated from gas gangrene and sporadic diarrhea cases carried both eut genes and the perfringolysin O gene (pfoA) as well as the phospholipase C gene (plc). However, pfoA was not detected in isolates from food poisoning patients and healthy volunteers. Culture supernatants prepared from HN13 grown in media containing 7.5% sheep red blood cells induced significantly higher eutB expression levels compared to those from plc- and/or pfoA-deletion mutants. Together, these results indicate that the eut system plays a nutritional role for C. perfringens during histolytic infection.
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Affiliation(s)
- Hirofumi Yagi
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan
| | - Haruyuki Nakayama-Imaohji
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan
| | - Hirofumi Nariya
- Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, 739-8528, Japan
| | - Ayano Tada
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan
| | - Hisashi Yamasaki
- Division of Biology, Hyogo College of Medicine, Mukogawa, Nishinomiya, 663-8501, Japan
| | - Hideyo Ugai
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan
| | - Miad Elahi
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan
| | - Tsuneko Ono
- Department of Molecular Microbiology, Institute of Health Biosciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Tomomi Kuwahara
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan.
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25
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Nawrocki KL, Wetzel D, Jones JB, Woods EC, McBride SM. Ethanolamine is a valuable nutrient source that impacts Clostridium difficile pathogenesis. Environ Microbiol 2018; 20:1419-1435. [PMID: 29349925 PMCID: PMC5903940 DOI: 10.1111/1462-2920.14048] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 01/03/2018] [Accepted: 01/14/2018] [Indexed: 12/12/2022]
Abstract
Clostridium (Clostridioides) difficile is a gastrointestinal pathogen that colonizes the intestinal tract of mammals and can cause severe diarrheal disease. Although C. difficile growth is confined to the intestinal tract, our understanding of the specific metabolites and host factors that are important for the growth of the bacterium is limited. In other enteric pathogens, the membrane-derived metabolite, ethanolamine (EA), is utilized as a nutrient source and can function as a signal to initiate the production of virulence factors. In this study, we investigated the effects of ethanolamine and the role of the predicted ethanolamine gene cluster (CD1907-CD1925) on C. difficile growth. Using targeted mutagenesis, we disrupted genes within the eut cluster and assessed their roles in ethanolamine utilization, and the impact of eut disruption on the outcome of infection in a hamster model of disease. Our results indicate that the eut gene cluster is required for the growth of C. difficile on ethanolamine as a primary nutrient source. Further, the inability to utilize ethanolamine resulted in greater virulence and a shorter time to morbidity in the animal model. Overall, these data suggest that ethanolamine is an important nutrient source within the host and that, in contrast to other intestinal pathogens, the metabolism of ethanolamine by C. difficile can delay the onset of disease.
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Affiliation(s)
- Kathryn L. Nawrocki
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniela Wetzel
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Joshua B. Jones
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Emily C. Woods
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Shonna M. McBride
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
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26
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Kuo CJ, Wang ST, Lin CM, Chiu HC, Huang CR, Lee DY, Chang GD, Chou TC, Chen JW, Chen CS. A multi-omic analysis reveals the role of fumarate in regulating the virulence of enterohemorrhagic Escherichia coli. Cell Death Dis 2018. [PMID: 29515100 PMCID: PMC5841434 DOI: 10.1038/s41419-018-0423-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The enteric pathogen enterohemorrhagic Escherichia coli (EHEC) is responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) worldwide. Several molecular mechanisms have been described for the pathogenicity of EHEC; however, the role of bacterial metabolism in the virulence of EHEC during infection in vivo remains unclear. Here we show that aerobic metabolism plays an important role in the regulation of EHEC virulence in Caenorhabditis elegans. Our functional genomic analyses showed that disruption of the genes encoding the succinate dehydrogenase complex (Sdh) of EHEC, including the sdhA gene, attenuated its toxicity toward C. elegans animals. Sdh converts succinate to fumarate and links the tricarboxylic acid (TCA) cycle and the electron transport chain (ETC) simultaneously. Succinate accumulation and fumarate depletion in the EHEC sdhA mutant cells were also demonstrated to be concomitant by metabolomic analyses. Moreover, fumarate replenishment to the sdhA mutant significantly increased its virulence toward C. elegans. These results suggest that the TCA cycle, ETC, and alteration in metabolome all account for the attenuated toxicity of the sdhA mutant, and Sdh catabolite fumarate in particular plays a critical role in the regulation of EHEC virulence. In addition, we identified the tryptophanase (TnaA) as a downstream virulence determinant of SdhA using a label-free proteomic method. We demonstrated that expression of tnaA is regulated by fumarate in EHEC. Taken together, our multi-omic analyses demonstrate that sdhA is required for the virulence of EHEC, and aerobic metabolism plays important roles in the pathogenicity of EHEC infection in C. elegans. Moreover, our study highlights the potential targeting of SdhA, if druggable, as alternative preventive or therapeutic strategies by which to combat EHEC infection.
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Affiliation(s)
- Cheng-Ju Kuo
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Sin-Tian Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chia-Mei Lin
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hao-Chieh Chiu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Cheng-Rung Huang
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Der-Yen Lee
- The Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan.,Graduate Institute of Biochemical Sciences, Technology Commons, Center for Systems Biology, National Taiwan University, Taipei, Taiwan
| | - Geen-Dong Chang
- Graduate Institute of Biochemical Sciences, Technology Commons, Center for Systems Biology, National Taiwan University, Taipei, Taiwan
| | - Ting-Chen Chou
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jenn-Wei Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan. .,Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
| | - Chang-Shi Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan. .,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
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27
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Sintsova A, Smith S, Subashchandrabose S, Mobley HL. Role of Ethanolamine Utilization Genes in Host Colonization during Urinary Tract Infection. Infect Immun 2018; 86:e00542-17. [PMID: 29229730 PMCID: PMC5820945 DOI: 10.1128/iai.00542-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/05/2017] [Indexed: 11/20/2022] Open
Abstract
Urinary tract infection (UTI) is the second most common infection in humans, making it a global health priority. Nearly half of all women will experience a symptomatic UTI, with uropathogenic Escherichia coli (UPEC) being the major causative agent of the infection. Although there has been extensive research on UPEC virulence determinants, the importance of host-specific metabolism remains understudied. We report here that UPEC upregulates the expression of ethanolamine utilization genes during uncomplicated UTIs in humans. We further show that UPEC ethanolamine metabolism is required for effective bladder colonization in the mouse model of ascending UTI and is dispensable for bladder colonization in an immunocompromised mouse model of UTI. We demonstrate that although ethanolamine metabolism mutants do not show increased susceptibility to antimicrobial responses of neutrophils, this metabolic pathway is important for surviving the innate immune system during UTI. This study reveals a novel aspect of UPEC metabolism in the host and provides evidence for an underappreciated link between bacterial metabolism and the host immune response.
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Affiliation(s)
- Anna Sintsova
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sara Smith
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Harry L Mobley
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
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28
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Abstract
Ethanolamine (EA) is a valuable source of carbon and/or nitrogen for bacteria capable of its catabolism. Because it is derived from the membrane phospholipid phosphatidylethanolamine, it is particularly prevalent in the gastrointestinal tract, which is membrane rich due to turnover of the intestinal epithelium and the resident microbiota. Intriguingly, many gut pathogens carry the eut (ethanolamine utilization) genes. EA utilization has been studied for about 50 years, with most of the early work occurring in just a couple of species of Enterobacteriaceae. Once the metabolic pathways and enzymes were characterized by biochemical approaches, genetic screens were used to map the various activities to the eut genes. With the rise of genomics, the diversity of bacteria containing the eut genes and surprising differences in eut gene content were recognized. Some species contain nearly 20 genes and encode many accessory proteins, while others contain only the core catabolic enzyme. Moreover, the eut genes are regulated by very different mechanisms, depending on the organism and the eut regulator encoded. In the last several years, exciting progress has been made in elucidating the complex regulatory mechanisms that govern eut gene expression. Furthermore, a new appreciation for how EA contributes to infection and colonization in the host is emerging. In addition to providing an overview of EA-related biology, this minireview will give special attention to these recent advances.
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29
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Carlson-Banning KM, Sperandio V. Enterohemorrhagic Escherichia coli outwits hosts through sensing small molecules. Curr Opin Microbiol 2018; 41:83-88. [PMID: 29258058 PMCID: PMC5862742 DOI: 10.1016/j.mib.2017.12.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/29/2017] [Accepted: 12/05/2017] [Indexed: 02/07/2023]
Abstract
Small molecules help intestinal pathogens navigate the complex human gastrointestinal tract to exploit favorable microhabitats. These small molecules provide spatial landmarks for pathogens to regulate synthesis of virulence caches and are derived from the host, ingested plant and animal material, and the microbiota. Their concentrations and fluxes vary along the length of the gut and provide molecular signatures that are beginning to be explored through metabolomics and genetics. However, while many small molecules have been identified and are reviewed here, there are undoubtedly others that may also profoundly affect how enteric pathogens infect their hosts.
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Affiliation(s)
- Kimberly M Carlson-Banning
- Departments of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vanessa Sperandio
- Departments of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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30
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Anderson CJ, Kendall MM. Salmonella enterica Serovar Typhimurium Strategies for Host Adaptation. Front Microbiol 2017; 8:1983. [PMID: 29075247 PMCID: PMC5643478 DOI: 10.3389/fmicb.2017.01983] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 09/26/2017] [Indexed: 12/21/2022] Open
Abstract
Bacterial pathogens must sense and respond to newly encountered host environments to regulate the expression of critical virulence factors that allow for niche adaptation and successful colonization. Among bacterial pathogens, non-typhoidal serovars of Salmonella enterica, such as serovar Typhimurium (S. Tm), are a primary cause of foodborne illnesses that lead to hospitalizations and deaths worldwide. S. Tm causes acute inflammatory diarrhea that can progress to invasive systemic disease in susceptible patients. The gastrointestinal tract and intramacrophage environments are two critically important niches during S. Tm infection, and each presents unique challenges to limit S. Tm growth. The intestinal tract is home to billions of commensal microbes, termed the microbiota, which limits the amount of available nutrients for invading pathogens such as S. Tm. Therefore, S. Tm encodes strategies to manipulate the commensal population and side-step this nutritional competition. During subsequent stages of disease, S. Tm resists host immune cell mechanisms of killing. Host cells use antimicrobial peptides, acidification of vacuoles, and nutrient limitation to kill phagocytosed microbes, and yet S. Tm is able to subvert these defense systems. In this review, we discuss recently described molecular mechanisms that S. Tm uses to outcompete the resident microbiota within the gastrointestinal tract. S. Tm directly eliminates close competitors via bacterial cell-to-cell contact as well as by stimulating a host immune response to eliminate specific members of the microbiota. Additionally, S. Tm tightly regulates the expression of key virulence factors that enable S. Tm to withstand host immune defenses within macrophages. Additionally, we highlight the chemical and physical signals that S. Tm senses as cues to adapt to each of these environments. These strategies ultimately allow S. Tm to successfully adapt to these two disparate host environments. It is critical to better understand bacterial adaptation strategies because disruption of these pathways and mechanisms, especially those shared by multiple pathogens, may provide novel therapeutic intervention strategies.
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Affiliation(s)
- Christopher J Anderson
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine,, Charlottesville, VA, United States
| | - Melissa M Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine,, Charlottesville, VA, United States
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31
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Fozo EM, Rucks EA. The Making and Taking of Lipids: The Role of Bacterial Lipid Synthesis and the Harnessing of Host Lipids in Bacterial Pathogenesis. Adv Microb Physiol 2016; 69:51-155. [PMID: 27720012 DOI: 10.1016/bs.ampbs.2016.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In order to survive environmental stressors, including those induced by growth in the human host, bacterial pathogens will adjust their membrane physiology accordingly. These physiological changes also include the use of host-derived lipids to alter their own membranes and feed central metabolic pathways. Within the host, the pathogen is exposed to many stressful stimuli. A resulting adaptation is for pathogens to scavenge the host environment for readily available lipid sources. The pathogen takes advantage of these host-derived lipids to increase or decrease the rigidity of their own membranes, to provide themselves with valuable precursors to feed central metabolic pathways, or to impact host signalling and processes. Within, we review the diverse mechanisms that both extracellular and intracellular pathogens employ to alter their own membranes as well as their use of host-derived lipids in membrane synthesis and modification, in order to increase survival and perpetuate disease within the human host. Furthermore, we discuss how pathogen employed mechanistic utilization of host-derived lipids allows for their persistence, survival and potentiation of disease. A more thorough understanding of all of these mechanisms will have direct consequences for the development of new therapeutics, and specifically, therapeutics that target pathogens, while preserving normal flora.
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Affiliation(s)
- E M Fozo
- University of Tennessee, Knoxville, TN, United States.
| | - E A Rucks
- Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States.
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32
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Monteiro R, Ageorges V, Rojas-Lopez M, Schmidt H, Weiss A, Bertin Y, Forano E, Jubelin G, Henderson IR, Livrelli V, Gobert AP, Rosini R, Soriani M, Desvaux M. A secretome view of colonisation factors in Shiga toxin-encodingEscherichia coli(STEC): from enterohaemorrhagicE. coli(EHEC) to related enteropathotypes. FEMS Microbiol Lett 2016; 363:fnw179. [DOI: 10.1093/femsle/fnw179] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2016] [Indexed: 12/25/2022] Open
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33
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McKenney ES, Kendall MM. Microbiota and pathogen 'pas de deux': setting up and breaking down barriers to intestinal infection. Pathog Dis 2016; 74:ftw051. [PMID: 27252177 PMCID: PMC5985477 DOI: 10.1093/femspd/ftw051] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/04/2016] [Accepted: 05/24/2016] [Indexed: 02/07/2023] Open
Abstract
The gut microbiota plays essential roles in human health and disease. In this review, we focus on the role of the intestinal microbiota in promoting resistance to infection by bacterial pathogens as well as how pathogens overcome this barrier. We discuss how the resident microbiota restricts growth and colonization of invading pathogens by limiting availability of nutrients and through generation of a hostile environment. Additionally, we examine how microbiota-derived signaling molecules interfere with bacterial virulence. In turn, we discuss how pathogens exploit non-competitive metabolites to replicate in vivo as well as to precisely control virulence and cause disease. This bacterial two step of creating and overcoming challenges important in preventing and establishing infection highlights the complexities of elucidating interactions between the commensal bacteria and pathogens. Better understanding of microbiota-pathogen interplay will have significant implications for developing novel therapeutics to treat infectious diseases.
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Affiliation(s)
- Elizabeth S McKenney
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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34
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The Type Three Secretion System 2-Encoded Regulator EtrB Modulates Enterohemorrhagic Escherichia coli Virulence Gene Expression. Infect Immun 2016; 84:2555-65. [PMID: 27324484 DOI: 10.1128/iai.00407-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/15/2016] [Indexed: 11/20/2022] Open
Abstract
Enterohemorrhagic Escherichia coli O157:H7 (EHEC) is a foodborne pathogen that causes bloody diarrhea and hemolytic uremic syndrome throughout the world. A defining feature of EHEC pathogenesis is the formation of attaching and effacing (AE) lesions on colonic epithelial cells. Most of the genes that code for AE lesion formation, including a type three secretion system (T3SS) and effectors, are carried within a chromosomal pathogenicity island called the locus of enterocyte effacement (LEE). In this study, we report that a putative regulator, which is encoded in the cryptic E. coli type three secretion system 2 (ETT2) locus and herein renamed EtrB, plays an important role in EHEC pathogenesis. The etrB gene is expressed as a monocistronic transcript, and EtrB autoregulates expression. We provide evidence that EtrB directly interacts with the ler regulatory region to activate LEE expression and promote AE lesion formation. Additionally, we mapped the EtrB regulatory circuit in EHEC to determine a global role for EtrB. EtrB is regulated by the transcription factor QseA, suggesting that these proteins comprise a regulatory circuit important for EHEC colonization of the gastrointestinal tract.
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35
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Abstract
Chemical signaling between cells is an effective way to coordinate behavior within a community. Although cell-to-cell signaling has mostly been studied in single species, it is now appreciated that the sensing of chemical signals across kingdoms can be an important regulator of nutrient acquisition, virulence, and host defense. In this review, we focus on the role of interkingdom signaling in the interactions that occur between bacterial pathogens and their mammalian hosts. We discuss the quorum-sensing (QS) systems and other mechanisms used by these bacteria to sense, respond to, and modulate host signals that include hormones, immune factors, and nutrients. We also describe cross talk between these signaling pathways and strategies used by the host to interfere with bacterial signaling, highlighting the complex bidirectional signaling networks that are established across kingdoms.
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36
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Luzader DH, Kendall MM. Commensal 'trail of bread crumbs' provide pathogens with a map to the intestinal landscape. Curr Opin Microbiol 2015; 29:68-73. [PMID: 26707739 DOI: 10.1016/j.mib.2015.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/19/2015] [Accepted: 11/26/2015] [Indexed: 12/31/2022]
Abstract
Growth of a microorganism in a host is essential for infection, and bacterial pathogens have evolved to utilize specific metabolites to enhance replication in vivo. Now, emerging data demonstrate that pathogens rely on microbiota-derived metabolites as a form of bacterial-bacterial communication to gain information about location within a host and modify virulence gene expression accordingly. Thus, metabolite-sensing is critical for pathogens to establish infection. Here, we highlight recent examples of how the foodborne pathogen enterohemorrhagic Escherichia coli O157:H7 (EHEC) exploits microbiota-derived metabolites to recognize the host intestinal environment and control gene expression that results in controlled expression of virulence traits.
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Affiliation(s)
- Deborah H Luzader
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, 1340 Jefferson Park Ave., Charlottesville, VA 22908, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, 1340 Jefferson Park Ave., Charlottesville, VA 22908, USA.
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37
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Anderson CJ, Clark DE, Adli M, Kendall MM. Ethanolamine Signaling Promotes Salmonella Niche Recognition and Adaptation during Infection. PLoS Pathog 2015; 11:e1005278. [PMID: 26565973 PMCID: PMC4643982 DOI: 10.1371/journal.ppat.1005278] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 10/22/2015] [Indexed: 12/21/2022] Open
Abstract
Chemical and nutrient signaling are fundamental for all cellular processes, including interactions between the mammalian host and the microbiota, which have a significant impact on health and disease. Ethanolamine is an essential component of cell membranes and has profound signaling activity within mammalian cells by modulating inflammatory responses and intestinal physiology. Here, we describe a virulence-regulating pathway in which the foodborne pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) exploits ethanolamine signaling to recognize and adapt to distinct niches within the host. The bacterial transcription factor EutR promotes ethanolamine metabolism in the intestine, which enables S. Typhimurium to establish infection. Subsequently, EutR directly activates expression of the Salmonella pathogenicity island 2 in the intramacrophage environment, and thus augments intramacrophage survival. Moreover, EutR is critical for robust dissemination during mammalian infection. Our findings reveal that S. Typhimurium co-opts ethanolamine as a signal to coordinate metabolism and then virulence. Because the ability to sense ethanolamine is a conserved trait among pathogenic and commensal bacteria, our work indicates that ethanolamine signaling may be a key step in the localized adaptation of bacteria within their mammalian hosts.
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Affiliation(s)
- Christopher J. Anderson
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - David E. Clark
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Mazhar Adli
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Melissa M. Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
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38
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Cameron EA, Sperandio V. Frenemies: Signaling and Nutritional Integration in Pathogen-Microbiota-Host Interactions. Cell Host Microbe 2015; 18:275-84. [PMID: 26355214 PMCID: PMC4567707 DOI: 10.1016/j.chom.2015.08.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The mammalian gastrointestinal (GI) microbiota is highly adapted to thrive in the GI environment and performs key functions related to host nutrition, physiology, development, immunity, and behavior. Successful host-bacterial associations require chemical signaling and optimal nutrient utilization and exchange. However, this important balance can be severely disrupted by environmental stimuli, with one of the most common insults upon the microbiota being infectious diseases. Although the microbiota acts as a barrier toward enteric pathogens, many enteric pathogens exploit signals and nutrients derived from both the microbiota and host to regulate their virulence programs. Here we review several signaling and nutrient recognition systems employed by GI pathogens to regulate growth and virulence. We discuss how shifts in the microbiota composition change host susceptibility to infection and how dietary changes or manipulation of the microbiota could potentially prevent and/or ameliorate GI infections.
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Affiliation(s)
- Elizabeth A Cameron
- Departments of Microbiology and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390-9048, USA
| | - Vanessa Sperandio
- Departments of Microbiology and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390-9048, USA.
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39
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Connolly JPR, Finlay BB, Roe AJ. From ingestion to colonization: the influence of the host environment on regulation of the LEE encoded type III secretion system in enterohaemorrhagic Escherichia coli. Front Microbiol 2015; 6:568. [PMID: 26097473 PMCID: PMC4456613 DOI: 10.3389/fmicb.2015.00568] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/24/2015] [Indexed: 12/21/2022] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) binds to host tissue and intimately attaches to intestinal cells using a dedicated type III secretion system (T3SS). This complex multi-protein organelle is encoded within a large pathogenicity island called the locus of enterocyte effacement (LEE), which is subject to extensive regulatory control. Over the past 15 years we have gained a wealth of knowledge concerning how the LEE is regulated transcriptionally by specific, global and phage encoded regulators. More recently, significant advances have been made in our understanding of how specific signals, including host or microbiota derived metabolic products and various nutrient sources, can affect how the LEE-encoded T3SS is regulated. In this review we discuss regulation of the LEE, focusing on how these physiologically relevant signals are sensed and how they affect the expression of this major virulence factor. The implications for understanding the disease process by specific regulatory mechanisms are also discussed.
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Affiliation(s)
- James P R Connolly
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow , Glasgow, UK
| | - B Brett Finlay
- Michael Smith Laboratories, University of British Columbia , Vancouver, BC, Canada
| | - Andrew J Roe
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow , Glasgow, UK
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40
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Morgan JK, Ortiz JA, Riordan JT. The role for TolA in enterohemorrhagic Escherichia coli pathogenesis and virulence gene transcription. Microb Pathog 2014; 77:42-52. [DOI: 10.1016/j.micpath.2014.10.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 10/14/2014] [Accepted: 10/21/2014] [Indexed: 01/16/2023]
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41
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Kendall MM, Sperandio V. Cell-to-Cell Signaling in Escherichia coli and Salmonella. EcoSal Plus 2014; 6:10.1128/ecosalplus.ESP-0002-2013. [PMID: 26442936 PMCID: PMC4229655 DOI: 10.1128/ecosalplus.esp-0002-2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Indexed: 01/21/2023]
Abstract
Bacteria must be able to respond rapidly to changes in the environment to survive. One means of coordinating gene expression relies on tightly regulated and complex signaling systems. One of the first signaling systems that was described in detail is quorum sensing (QS). During QS, a bacterial cell produces and secretes a signaling molecule called an autoinducer (AI). As the density of the bacterial population increases, so does the concentration of secreted AI molecules, thereby allowing a bacterial species to coordinate gene expression based on population density. Subsequent studies have demonstrated that bacteria are also able to detect signal molecules produced by other species of bacteria as well as hormones produced by their mammalian hosts. This type of signaling interaction has been termed cell-to-cell signaling because it does not rely on a threshold concentration of bacterial cells. This review discusses the three main types of cell-to-cell signaling mechanisms used by Escherichia coli and Salmonella: the LuxR process, in which E. coli and Salmonella detect signals produced by other species of bacteria; the LuxS/AI-2 system, in which E. coli and Salmonella participate in intra- and interspecies signaling; and the AI-3/epinephrine/norepinephrine system, in which E. coli and Salmonella recognize self-produced AI, signal produced by other microbes, and/or the human stress hormones epinephrine and/or norepinephrine.
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Affiliation(s)
- Melissa M. Kendall
- Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Vanessa Sperandio
- Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
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