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Calderon Toledo C, von Mentzer A, Agramont J, Thorell K, Zhou Y, Szabó M, Colque P, Kuhn I, Gutiérrez-Cortez S, Joffré E. Circulation of enterotoxigenic Escherichia coli (ETEC) isolates expressing CS23 from the environment to clinical settings. mSystems 2023; 8:e0014123. [PMID: 37681982 PMCID: PMC10654058 DOI: 10.1128/msystems.00141-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/27/2023] [Indexed: 09/09/2023] Open
Abstract
IMPORTANCE The importance of clean water cannot be overstated. It is a vital resource for maintaining health and well-being. Unfortunately, water sources contaminated with fecal discharges from animal and human origin due to a lack of wastewater management pose a significant risk to communities, as they can become a means of transmission of pathogenic bacteria like enterotoxigenic E. coli (ETEC). ETEC is frequently found in polluted water in countries with a high prevalence of diarrheal diseases, such as Bolivia. This study provides novel insights into the circulation of ETEC between diarrheal cases and polluted water sources in areas with high rates of diarrheal disease. These findings highlight the Choqueyapu River as a potential reservoir for emerging pathogens carrying antibiotic-resistance genes, making it a crucial area for monitoring and intervention. Furthermore, the results demonstrate the feasibility of a low-cost, high-throughput method for tracking bacterial pathogens in low- and middle-income countries, making it a valuable tool for One Health monitoring efforts.
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Affiliation(s)
- Carla Calderon Toledo
- Unidad de Microbiología Ambiental, Instituto de Biología Molecular y Biotecnología (IBMB), Carrera de Biología, Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Astrid von Mentzer
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Jorge Agramont
- Unidad de Microbiología Ambiental, Instituto de Biología Molecular y Biotecnología (IBMB), Carrera de Biología, Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Kaisa Thorell
- Department of Chemistry and Molecular Biology (CMB), University of Gothenburg, Gothenburg, Sweden
| | - Yingshun Zhou
- Department of Pathogen Biology, The public platform of the Pathogen Biology, School of Basic Medicine, Southwest Medical University, Luzhou, Sichuan, China
| | - Miklós Szabó
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
| | - Patricia Colque
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
| | - Inger Kuhn
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
| | - Sergio Gutiérrez-Cortez
- Unidad de Microbiología Ambiental, Instituto de Biología Molecular y Biotecnología (IBMB), Carrera de Biología, Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Enrique Joffré
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
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Jinno C, Wong B, Klünemann M, Htoo J, Li X, Liu Y. Effects of supplementation of Bacillus amyloliquefaciens on performance, systemic immunity, and intestinal microbiota of weaned pigs experimentally infected with a pathogenic enterotoxigenic E. coli F18. Front Microbiol 2023; 14:1101457. [PMID: 37007512 PMCID: PMC10050357 DOI: 10.3389/fmicb.2023.1101457] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/20/2023] [Indexed: 03/17/2023] Open
Abstract
The objective of this study was to investigate the effects of dietary supplementation of Bacillus (B.) amyloliquefaciens on growth performance, diarrhea, systemic immunity, and intestinal microbiota of weaned pigs experimentally infected with F18 enterotoxigenic Escherichia coli (ETEC). A total of 50 weaned pigs (7.41 ± 1.35 kg BW) were individually housed and randomly allotted to one of the following five treatments: sham control (CON-), sham B. amyloliquefaciens (BAM-), challenged control (CON+), challenged B. amyloliquefaciens (BAM+), and challenged carbadox (AGP+). The experiment lasted 28 days, with 7 days of adaptation and 21 days after the first ETEC inoculation. ETEC challenge reduced (P < 0.05) average daily gain (ADG) of pigs. Compared with CON+, AGP+ enhanced (P < 0.05) ADG, while B. amyloliquefaciens supplementation tended (P < 0.10) to increase ADG in pigs from days 0 to 21 post-inoculation (PI). The ETEC challenge increased (P < 0.05) white blood cell (WBC) count on days 7 and 21 PI, while BAM+ pigs tended (P < 0.10) to have low WBC on day 7 PI and had lower (P < 0.05) WBC on day 21 PI compared with CON+. In comparison to AGP+ fecal microbiota, BAM+ had a lower (P < 0.05) relative abundance of Lachnospiraceae on day 0 and Clostridiaceae on day 21 PI, but a higher (P < 0.05) relative abundance of Enterobacyeriaceae on day 0. In ileal digesta, the Shannon index was higher (P < 0.05) in BAM+ than in AGP+. Bray-Curtis PCoA displayed a difference in bacterial community composition in ileal digesta collected from sham pigs vs. ETEC-infected pigs on day 21 PI. Pigs in BAM+ had a greater (P < 0.05) relative abundance of Firmicutes, but a lower (P < 0.05) relative abundance of Actinomycetota and Bacteroidota in ileal digesta than pigs in AGP+. Ileal digesta from AGP+ had a greater (P < 0.05) abundance of Clostridium sensu stricto 1 but lower (P < 0.05) Bifidobacterium than pigs in BAM+. In conclusion, supplementation of B. amyloliquefaciens tended to increase ADG and had limited effects on the diarrhea of ETEC-infected pigs. However, pigs fed with B. amyloliquefaciens exhibit milder systemic inflammation than controls. B. amyloliquefaciens differently modified the intestinal microbiota of weaned pigs compared with carbadox.
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Affiliation(s)
- Cynthia Jinno
- Department of Animal Science, University of California, Davis, Davis, CA, United States
| | - Braden Wong
- Department of Animal Science, University of California, Davis, Davis, CA, United States
| | | | - John Htoo
- Evonik Operations GmbH, Hanau, Germany
| | - Xunde Li
- Department of Animal Science, University of California, Davis, Davis, CA, United States
| | - Yanhong Liu
- Department of Animal Science, University of California, Davis, Davis, CA, United States
- *Correspondence: Yanhong Liu
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Sauvaitre T, Van Landuyt J, Durif C, Roussel C, Sivignon A, Chalancon S, Uriot O, Van Herreweghen F, Van de Wiele T, Etienne-Mesmin L, Blanquet-Diot S. Role of mucus-bacteria interactions in Enterotoxigenic Escherichia coli (ETEC) H10407 virulence and interplay with human microbiome. NPJ Biofilms Microbiomes 2022; 8:86. [PMID: 36266277 PMCID: PMC9584927 DOI: 10.1038/s41522-022-00344-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/04/2022] [Indexed: 11/09/2022] Open
Abstract
The intestinal mucus layer has a dual role in human health constituting a well-known microbial niche that supports gut microbiota maintenance but also acting as a physical barrier against enteric pathogens. Enterotoxigenic Escherichia coli (ETEC), the major agent responsible for traveler's diarrhea, is able to bind and degrade intestinal mucins, representing an important but understudied virulent trait of the pathogen. Using a set of complementary in vitro approaches simulating the human digestive environment, this study aimed to describe how the mucus microenvironment could shape different aspects of the human ETEC strain H10407 pathophysiology, namely its survival, adhesion, virulence gene expression, interleukin-8 induction and interactions with human fecal microbiota. Using the TNO gastrointestinal model (TIM-1) simulating the physicochemical conditions of the human upper gastrointestinal (GI) tract, we reported that mucus secretion and physical surface sustained ETEC survival, probably by helping it to face GI stresses. When integrating the host part in Caco2/HT29-MTX co-culture model, we demonstrated that mucus secreting-cells favored ETEC adhesion and virulence gene expression, but did not impede ETEC Interleukin-8 (IL-8) induction. Furthermore, we proved that mucosal surface did not favor ETEC colonization in a complex gut microbial background simulated in batch fecal experiments. However, the mucus-specific microbiota was widely modified upon the ETEC challenge suggesting its role in the pathogen infectious cycle. Using multi-targeted in vitro approaches, this study supports the major role played by mucus in ETEC pathophysiology, opening avenues in the design of new treatment strategies.
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Affiliation(s)
- Thomas Sauvaitre
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France.,Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Josefien Van Landuyt
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Claude Durif
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Charlène Roussel
- Université Laval, Nutrition and Functional Foods Institute (INAF), 2440 Bd Hochelaga Suite 1710, Québec, QC, G1V 0A6, Canada
| | - Adeline Sivignon
- Université Clermont Auvergne, UMR 1071 Inserm, USC-INRAE 2018, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte (M2iSH), 63000, Clermont-Ferrand, France
| | - Sandrine Chalancon
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Ophélie Uriot
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Florence Van Herreweghen
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Tom Van de Wiele
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Lucie Etienne-Mesmin
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Stéphanie Blanquet-Diot
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France.
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4
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Joffré E, Xiao X, Correia MSP, Nookaew I, Sasse S, Globisch D, Zhu B, Sjöling Å. Analysis of Growth Phases of Enterotoxigenic Escherichia coli Reveals a Distinct Transition Phase before Entry into Early Stationary Phase with Shifts in Tryptophan, Fucose, and Putrescine Metabolism and Degradation of Neurotransmitter Precursors. Microbiol Spectr 2022; 10:e0175521. [PMID: 35876501 PMCID: PMC9431495 DOI: 10.1128/spectrum.01755-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 03/03/2022] [Indexed: 11/20/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and adults in endemic areas. Gene regulation of ETEC during growth in vitro and in vivo needs to be further evaluated, and here we describe the full transcriptome and metabolome of ETEC during growth from mid-logarithmic growth to early stationary phase in rich medium (LB medium). We identified specific genes and pathways subjected to rapid transient alterations in gene expression and metabolite production during the transition from logarithmic to stationary growth. The transient phase was found to be different from the subsequent induction of early stationary phase-induced genes. The transient phase was characterized by the repression of genes and metabolites involved in organic substance transport. Genes involved in fucose and putrescine metabolism were upregulated, and genes involved in iron transport were repressed. Expression of toxins and colonization factors were not changed, suggesting retained virulence from mid-logarithmic to the start of the stationary phase. Metabolomic analyses showed that the transient phase was characterized by a drop of intracellular amino acids, e.g., l-tyrosine, l-tryptophan, l-phenylalanine, l-leucine, and l-glutamic acid, followed by increased levels at induction of stationary phase. A pathway enrichment analysis of the entire combined transcriptome and metabolome revealed that significant pathways during progression from logarithmic to early stationary phase are involved in the degradation of neurotransmitters aminobutyrate (GABA) and precursors of 5-hydroxytryptamine (serotonin). This work provides a comprehensive framework for further studies on transcriptional and metabolic regulation in pathogenic E. coli. IMPORTANCE We show that E. coli, exemplified by the pathogenic subspecies enterotoxigenic E. coli (ETEC), undergoes a stepwise transcriptional and metabolic transition into the stationary phase. At a specific entry point, E. coli induces activation and repression of specific pathways. This leads to a rapid decrease of intracellular levels of certain amino acids. The resulting metabolic activity leads to an intense but short peak of indole production, suggesting that this is the previously described "indole peak," rapid decrease of intermediate molecules of bacterial neurotransmitters, increased putrescine and fucose uptake, increased glutathione levels, and decreased iron uptake. This specific transient shift in gene expression and metabolome is short-lived and disappears when bacteria enter the early stationary phase. We suggest that these changes mainly prepare bacteria for ceased growth, but based on the pathways involved, we could suggest that this transient phase substantially influences survival and virulence.
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Affiliation(s)
- Enrique Joffré
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
| | - Xue Xiao
- CAS Key Laboratory of Pathogenic Microbiology & Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Mário S. P. Correia
- Department of Chemistry - BMC, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Intawat Nookaew
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Samantha Sasse
- Department of Chemistry - BMC, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Daniel Globisch
- Department of Chemistry - BMC, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Baoli Zhu
- CAS Key Laboratory of Pathogenic Microbiology & Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Åsa Sjöling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
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Intestinal Epithelial Cells Modulate the Production of Enterotoxins by Porcine Enterotoxigenic E. coli Strains. Int J Mol Sci 2022; 23:ijms23126589. [PMID: 35743033 PMCID: PMC9223395 DOI: 10.3390/ijms23126589] [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: 05/17/2022] [Revised: 06/03/2022] [Accepted: 06/12/2022] [Indexed: 01/23/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are one of the most common etiological agents of diarrhea in both human and farm animals. In addition to encoding toxins that cause diarrhea, ETEC have evolved numerous strategies to interfere with host defenses. These strategies most likely depend on the sensing of host factors, such as molecules secreted by gut epithelial cells. The present study tested whether the exposure of ETEC to factors secreted by polarized IPEC-J2 cells resulted in transcriptional changes of ETEC-derived virulence factors. Following the addition of host-derived epithelial factors, genes encoding enterotoxins, secretion-system-associated proteins, and the key regulatory molecule cyclic AMP (cAMP) receptor protein (CRP) were substantially modulated, suggesting that ETEC recognize and respond to factors produced by gut epithelial cells. To determine whether these factors were heat sensitive, the IEC-conditioned medium was incubated at 56 °C for 30 min. In most ETEC strains, heat treatment of the IEC-conditioned medium resulted in a loss of transcriptional modulation. Taken together, these data suggest that secreted epithelial factors play a role in bacterial pathogenesis by modulating the transcription of genes encoding key ETEC virulence factors. Further research is warranted to identify these secreted epithelial factors and how ETEC sense these molecules to gain a competitive advantage in the early engagement of the gut epithelium.
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Sauvaitre T, Van Herreweghen F, Delbaere K, Durif C, Van Landuyt J, Fadhlaoui K, Huille S, Chaucheyras-Durand F, Etienne-Mesmin L, Blanquet-Diot S, Van de Wiele T. Lentils and Yeast Fibers: A New Strategy to Mitigate Enterotoxigenic Escherichia coli (ETEC) Strain H10407 Virulence? Nutrients 2022; 14:nu14102146. [PMID: 35631287 PMCID: PMC9144138 DOI: 10.3390/nu14102146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 01/10/2023] Open
Abstract
Dietary fibers exhibit well-known beneficial effects on human health, but their anti-infectious properties against enteric pathogens have been poorly investigated. Enterotoxigenic Escherichia coli (ETEC) is a major food-borne pathogen that causes acute traveler’s diarrhea. Its virulence traits mainly rely on adhesion to an epithelial surface, mucus degradation, and the secretion of two enterotoxins associated with intestinal inflammation. With the increasing burden of antibiotic resistance worldwide, there is an imperious need to develop novel alternative strategies to control ETEC infections. This study aimed to investigate, using complementary in vitro approaches, the inhibitory potential of two dietary-fiber-containing products (a lentil extract and yeast cell walls) against the human ETEC reference strain H10407. We showed that the lentil extract decreased toxin production in a dose-dependent manner, reduced pro-inflammatory interleukin-8 production, and modulated mucus-related gene induction in ETEC-infected mucus-secreting intestinal cells. We also report that the yeast product reduced ETEC adhesion to mucin and Caco-2/HT29-MTX cells. Both fiber-containing products strengthened intestinal barrier function and modulated toxin-related gene expression. In a complex human gut microbial background, both products did not elicit a significant effect on ETEC colonization. These pioneering data demonstrate the promising role of dietary fibers in controlling different stages of the ETEC infection process.
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Affiliation(s)
- Thomas Sauvaitre
- UMR 454 INRAE, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France; (T.S.); (C.D.); (K.F.); (F.C.-D.); (L.E.-M.)
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (F.V.H.); (K.D.); (J.V.L.); (T.V.d.W.)
| | - Florence Van Herreweghen
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (F.V.H.); (K.D.); (J.V.L.); (T.V.d.W.)
| | - Karen Delbaere
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (F.V.H.); (K.D.); (J.V.L.); (T.V.d.W.)
| | - Claude Durif
- UMR 454 INRAE, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France; (T.S.); (C.D.); (K.F.); (F.C.-D.); (L.E.-M.)
| | - Josefien Van Landuyt
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (F.V.H.); (K.D.); (J.V.L.); (T.V.d.W.)
| | - Khaled Fadhlaoui
- UMR 454 INRAE, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France; (T.S.); (C.D.); (K.F.); (F.C.-D.); (L.E.-M.)
| | | | - Frédérique Chaucheyras-Durand
- UMR 454 INRAE, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France; (T.S.); (C.D.); (K.F.); (F.C.-D.); (L.E.-M.)
- Lallemand SAS, 19 Rue des Briquetiers, BP 59, CEDEX, F-31702 Blagnac, France
| | - Lucie Etienne-Mesmin
- UMR 454 INRAE, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France; (T.S.); (C.D.); (K.F.); (F.C.-D.); (L.E.-M.)
| | - Stéphanie Blanquet-Diot
- UMR 454 INRAE, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France; (T.S.); (C.D.); (K.F.); (F.C.-D.); (L.E.-M.)
- Correspondence: ; Tel.: +33-(0)4-73-17-83-90
| | - Tom Van de Wiele
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; (F.V.H.); (K.D.); (J.V.L.); (T.V.d.W.)
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Skowron K, Budzyńska A, Grudlewska-Buda K, Wiktorczyk-Kapischke N, Andrzejewska M, Wałecka-Zacharska E, Gospodarek-Komkowska E. Two Faces of Fermented Foods-The Benefits and Threats of Its Consumption. Front Microbiol 2022; 13:845166. [PMID: 35330774 PMCID: PMC8940296 DOI: 10.3389/fmicb.2022.845166] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 02/15/2022] [Indexed: 12/17/2022] Open
Abstract
In underdeveloped and developing countries, due to poverty, fermentation is one of the most widely used preservation methods. It not only allows extending the shelf life of food, but also brings other benefits, including inhibiting the growth of pathogenic microorganisms, improving the organoleptic properties and product digestibility, and can be a valuable source of functional microorganisms. Today, there is a great interest in functional strains, which, in addition to typical probiotic strains, can participate in the treatment of numerous diseases, disorders of the digestive system, but also mental diseases, or stimulate our immune system. Hence, fermented foods and beverages are not only a part of the traditional diet, e.g., in Africa but also play a role in the nutrition of people around the world. The fermentation process for some products occurs spontaneously, without the use of well-defined starter cultures, under poorly controlled or uncontrolled conditions. Therefore, while this affordable technology has many advantages, it can also pose a potential health risk. The use of poor-quality ingredients, inadequate hygiene conditions in the manufacturing processes, the lack of standards for safety and hygiene controls lead to the failure food safety systems implementation, especially in low- and middle-income countries or for small-scale products (at household level, in villages and scale cottage industries). This can result in the presence of pathogenic microorganisms or their toxins in the food contributing to cases of illness or even outbreaks. Also, improper processing and storage, as by well as the conditions of sale affect the food safety. Foodborne diseases through the consumption of traditional fermented foods are not reported frequently, but this may be related, among other things, to a low percentage of people entering healthcare care or weaknesses in foodborne disease surveillance systems. In many parts of the world, especially in Africa and Asia, pathogens such as enterotoxigenic and enterohemorrhagic Escherichia coli, Shigella spp., Salmonella spp., enterotoxigenic Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus have been detected in fermented foods. Therefore, this review, in addition to the positive aspects, presents the potential risk associated with the consumption of this type of products.
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Affiliation(s)
- Krzysztof Skowron
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Anna Budzyńska
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Katarzyna Grudlewska-Buda
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Natalia Wiktorczyk-Kapischke
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Małgorzata Andrzejewska
- Department of Hygiene, Epidemiology, Ergonomy and Postgraduate Education, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Ewa Wałecka-Zacharska
- Department of Food Hygiene and Consumer Health, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Eugenia Gospodarek-Komkowska
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
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AB 5 Enterotoxin-Mediated Pathogenesis: Perspectives Gleaned from Shiga Toxins. Toxins (Basel) 2022; 14:toxins14010062. [PMID: 35051039 PMCID: PMC8779504 DOI: 10.3390/toxins14010062] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 02/01/2023] Open
Abstract
Foodborne diseases affect an estimated 600 million people worldwide annually, with the majority of these illnesses caused by Norovirus, Vibrio, Listeria, Campylobacter, Salmonella, and Escherichia coli. To elicit infections in humans, bacterial pathogens express a combination of virulence factors and toxins. AB5 toxins are an example of such toxins that can cause various clinical manifestations, including dehydration, diarrhea, kidney damage, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Treatment of most bacterial foodborne illnesses consists of fluid replacement and antibiotics. However, antibiotics are not recommended for infections caused by Shiga toxin-producing E. coli (STEC) because of the increased risk of HUS development, although there are conflicting views and results in this regard. Lack of effective treatment strategies for STEC infections pose a public health threat during outbreaks; therefore, the debate on antibiotic use for STEC infections could be further explored, along with investigations into antibiotic alternatives. The overall goal of this review is to provide a succinct summary on the mechanisms of action and the pathogenesis of AB5 and related toxins, as expressed by bacterial foodborne pathogens, with a primary focus on Shiga toxins (Stx). The role of Stx in human STEC disease, detection methodologies, and available treatment options are also briefly discussed.
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9
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Yang D, Jiang F, Huang X, Li G, Cai W. Transcriptomic and Metabolomic Profiling Reveals That KguR Broadly Impacts the Physiology of Uropathogenic Escherichia coli Under in vivo Relevant Conditions. Front Microbiol 2022; 12:793391. [PMID: 34975816 PMCID: PMC8716947 DOI: 10.3389/fmicb.2021.793391] [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: 10/12/2021] [Accepted: 11/30/2021] [Indexed: 12/17/2022] Open
Abstract
Urinary tract infections are primarily caused by uropathogenic Escherichia coli (UPEC). In contrast to the intestinal E. coli strains that reside in nutrient-rich gut environment, UPEC encounter distinct niches, for instance human urine, which is an oxygen- and nutrient-limited environment. Alpha-ketoglutarate (KG) is an abundant metabolite in renal proximal tubule cells; and previously we showed that two-component signaling system (TCS) KguS/KguR contributes to UPEC colonization of murine urinary tract by promoting the utilization of KG as a carbon source under anaerobic conditions. However, knowledge about the KguR regulon and its impact on UPEC fitness is lacking. In this work, we analyzed transcriptomic and metabolomic changes caused by kguR deletion under anaerobiosis when KG is present. Our results indicated that 620 genes were differentially expressed in the ΔkguR mutant, as compared to the wild type; of these genes, 513 genes were downregulated and 107 genes were upregulated. Genes with substantial changes in expression involve KG utilization, acid resistance, iron uptake, amino acid metabolism, capsule biosynthesis, sulfur metabolism, among others. In line with the transcriptomics data, several amino acids (glutamate, lysine, etc.) and uridine 5′-diphosphogalactose (involved in capsule biosynthesis) were significantly less abundant in the ΔkguR mutant. We then confirmed that the ΔkguR mutant, indeed, was more sensitive to acid stress than the wild type, presumably due to downregulation of genes belonging to the glutamate-dependent acid resistance system. Furthermore, using gene expression and electrophoretic mobility shift assays (EMSAs), we demonstrate that KguR autoregulates its own expression by binding to the kguSR promoter region. Lastly, we performed a genome-wide search of KguR binding sites, and this search yielded an output of at least 22 potential binding sites. Taken together, our data establish that in the presence of KG, KguR broadly impacts the physiology of UPEC under anaerobiosis. These findings greatly further our understanding of KguS/KguR system as well as UPEC pathobiology.
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Affiliation(s)
- Dawei Yang
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Fengwei Jiang
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xinxin Huang
- Technical Centre for Animal, Plant, and Food Inspection and Quarantine of Shanghai Customs, Shanghai, China
| | - Ganwu Li
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.,Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Wentong Cai
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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10
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Roussel C, De Paepe K, Galia W, De Bodt J, Chalancon S, Leriche F, Ballet N, Denis S, Alric M, Van de Wiele T, Blanquet-Diot S. Spatial and temporal modulation of enterotoxigenic E. coli H10407 pathogenesis and interplay with microbiota in human gut models. BMC Biol 2020; 18:141. [PMID: 33054775 PMCID: PMC7559199 DOI: 10.1186/s12915-020-00860-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 08/31/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Enterotoxigenic Escherichia coli (ETEC) substantially contributes to the burden of diarrheal illnesses in developing countries. With the use of complementary in vitro models of the human digestive environment, TNO gastrointestinal model (TIM-1), and Mucosal Simulator of the Human Intestinal Microbial Ecosystem (M-SHIME), we provided the first detailed report on the spatial-temporal modulation of ETEC H10407 survival, virulence, and its interplay with gut microbiota. These systems integrate the main physicochemical parameters of the human upper digestion (TIM-1) and simulate the ileum vs ascending colon microbial communities and luminal vs mucosal microenvironments, captured from six fecal donors (M-SHIME). RESULTS A loss of ETEC viability was noticed upon gastric digestion, while a growth renewal was found at the end of jejunal and ileal digestion. The remarkable ETEC mucosal attachment helped to maintain luminal concentrations above 6 log10 mL-1 in the ileum and ascending colon up to 5 days post-infection. Seven ETEC virulence genes were monitored. Most of them were switched on in the stomach and switched off in the TIM-1 ileal effluents and in a late post-infectious stage in the M-SHIME ascending colon. No heat-labile enterotoxin production was measured in the stomach in contrast to the ileum and ascending colon. Using 16S rRNA gene-based amplicon sequencing, ETEC infection modulated the microbial community structure of the ileum mucus and ascending colon lumen. CONCLUSIONS This study provides a better understanding of the interplay between ETEC and gastrointestinal cues and may serve to complete knowledge on ETEC pathogenesis and inspire novel prophylactic strategies for diarrheal diseases.
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Affiliation(s)
- Charlène Roussel
- Université Clermont Auvergne, UMR UCA-INRA 454 MEDIS, Microbiology Digestive Environment and Health, Clermont-Ferrand, France.,CMET, Center for Microbial Ecology and Technology, Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Kim De Paepe
- CMET, Center for Microbial Ecology and Technology, Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Wessam Galia
- UMR 5557 Microbial Ecology, Research Group on Bacterial Opportunistic Pathogens and Environment, CNRS, VetAgro Sup, Lyon, France
| | - Jana De Bodt
- CMET, Center for Microbial Ecology and Technology, Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sandrine Chalancon
- Université Clermont Auvergne, UMR UCA-INRA 454 MEDIS, Microbiology Digestive Environment and Health, Clermont-Ferrand, France
| | | | - Nathalie Ballet
- Lesaffre International, Lesaffre Group, Marcq-en-Baroeul, France
| | - Sylvain Denis
- Université Clermont Auvergne, UMR UCA-INRA 454 MEDIS, Microbiology Digestive Environment and Health, Clermont-Ferrand, France
| | - Monique Alric
- Université Clermont Auvergne, UMR UCA-INRA 454 MEDIS, Microbiology Digestive Environment and Health, Clermont-Ferrand, France
| | - Tom Van de Wiele
- CMET, Center for Microbial Ecology and Technology, Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
| | - Stéphanie Blanquet-Diot
- Université Clermont Auvergne, UMR UCA-INRA 454 MEDIS, Microbiology Digestive Environment and Health, Clermont-Ferrand, France.
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11
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Rodrigues JF, Lourenço RF, Maeda DLNF, de Jesus Cintra M, Nakao N, Mathias-Santos C, Luiz WB, de Souza Ferreira LC. Strain-specific transcriptional and posttranscriptional regulation of heat-labile toxin expression by enterotoxigenic Escherichia coli. Braz J Microbiol 2020; 51:455-465. [PMID: 32016818 PMCID: PMC7203263 DOI: 10.1007/s42770-020-00231-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 01/18/2020] [Indexed: 11/30/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) represents one of the most important etiological agents of diarrhea in developing countries and characteristically produces at least one of two enterotoxins: heat-labile toxin (LT) and heat-stable toxin (ST). It has been previously shown that the production and release of LT by human-derived ETEC strains are variable. Although the natural genetic polymorphisms of regulatory sequences of LT-encoding (eltAB) genes may explain the variable production of LT, the knowledge of the transcriptional and posttranscriptional aspects affecting LT expression among ETEC strains is not clear. To further understand the factors affecting LT expression, we evaluated the impact of the natural polymorphism in noncoding regulatory sequences of eltAB among clinically derived ETEC strains. Sequence analyses of seven clinically derived strains and the reference strain H10407 revealed polymorphic sites at both the promoter and upstream regions of the eltAB operon. Operon fusion assays with GFP revealed that specific nucleotide changes in the Pribnow box reduce eltAB transcription. Nonetheless, the total amounts of LT produced by the tested ETEC strains did not strictly correspond to the detected LT-specific mRNA levels. Indeed, the stability of LT varied according to the tested strain, indicating the presence of posttranscriptional mechanisms affecting LT expression. Taken together, our results indicate that the production of LT is a strain-specific process and involves transcriptional and posttranscriptional mechanisms that regulate the final amount of toxin produced and released by specific strains.
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Affiliation(s)
- Juliana Falcão Rodrigues
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil. .,Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Rogério Ferreira Lourenço
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.,Institute of Biology, The State University of Campinas, São Paulo, Brazil
| | - Denicar Lina Nascimento Fabris Maeda
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.,Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.,Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
| | - Mariana de Jesus Cintra
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - Naomi Nakao
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - Camila Mathias-Santos
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.,Technical-Scientific Police Superintendency, São Paulo State, Criminalistic Institute, São Paulo, Brazil
| | - Wilson Barros Luiz
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.,Department of Biological Sciences, State University of Santa Cruz, Ilhéus, Bahia, Brazil
| | - Luís Carlos de Souza Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.
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12
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Liquid chromatography-ultraviolet detection and quantification of heat-labile toxin produced by enterotoxigenic E. coli cultured under different conditions. Toxicon 2018; 141:73-78. [DOI: 10.1016/j.toxicon.2017.11.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/02/2017] [Accepted: 11/27/2017] [Indexed: 02/06/2023]
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13
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Pettersen VK, Steinsland H, Wiker HG. Comparative Proteomics of Enterotoxigenic Escherichia coli Reveals Differences in Surface Protein Production and Similarities in Metabolism. J Proteome Res 2017; 17:325-336. [DOI: 10.1021/acs.jproteome.7b00593] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Veronika Kuchařová Pettersen
- The Gade Research Group for Infection and Immunity, Department of
Clinical Science, ‡Centre for International Health, Department of Global Public Health
and Primary Care, and §Department of Biomedicine, University of Bergen, 5021 Bergen, Norway
| | - Hans Steinsland
- The Gade Research Group for Infection and Immunity, Department of
Clinical Science, ‡Centre for International Health, Department of Global Public Health
and Primary Care, and §Department of Biomedicine, University of Bergen, 5021 Bergen, Norway
| | - Harald G. Wiker
- The Gade Research Group for Infection and Immunity, Department of
Clinical Science, ‡Centre for International Health, Department of Global Public Health
and Primary Care, and §Department of Biomedicine, University of Bergen, 5021 Bergen, Norway
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14
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Gonzales-Siles L, Karlsson R, Kenny D, Karlsson A, Sjöling Å. Proteomic analysis of enterotoxigenic Escherichia coli (ETEC) in neutral and alkaline conditions. BMC Microbiol 2017; 17:11. [PMID: 28061865 PMCID: PMC5219706 DOI: 10.1186/s12866-016-0914-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 12/13/2016] [Indexed: 12/20/2022] Open
Abstract
Background Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and travelers to endemic areas. Secretion of the heat labile AB5 toxin (LT) is induced by alkaline conditions. In this study, we determined the surface proteome of ETEC exposed to alkaline conditions (pH 9) as compared to neutral conditions (pH 7) using a LPI Hexalane FlowCell combined with quantitative proteomics. Relative quantitation with isobaric labeling (TMT) was used to compare peptide abundance and their corresponding proteins in multiple samples at MS/MS level. For protein identification and quantification samples were analyzed using either a 1D-LCMS or a 2D-LCMS approach. Results Strong up-regulation of the ATP synthase operon encoding F1Fo ATP synthase and down-regulation of proton pumping proteins NuoF, NuoG, Ndh and WrbA were detected among proteins involved in regulating the proton and electron transport under alkaline conditions. Reduced expression of proteins involved in osmotic stress was found at alkaline conditions while the Sec-dependent transport over the inner membrane and outer membrane protein proteins such as OmpA and the β-Barrel Assembly Machinery (BAM) complex were up-regulated. Conclusions ETEC exposed to alkaline environments express a specific proteome profile characterized by up-regulation of membrane proteins and secretion of LT toxin. Alkaline microenvironments have been reported close to the intestinal epithelium and the alkaline proteome may hence represent a better view of ETEC during infection.
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Affiliation(s)
- Lucia Gonzales-Siles
- Department of Infectious Disease, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-41346, Gothenburg, Sweden.
| | | | - Diarmuid Kenny
- Proteomics Core Facility at the University of Gothenburg, SE-43050, Gothenburg, Sweden
| | | | - Åsa Sjöling
- Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, SE-17177, Sweden
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15
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Roussel C, Sivignon A, de Wiele TV, Blanquet-Diot S. Foodborne enterotoxigenic Escherichia coli: from gut pathogenesis to new preventive strategies involving probiotics. Future Microbiol 2016; 12:73-93. [PMID: 27983878 DOI: 10.2217/fmb-2016-0101] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are a major cause of traveler's diarrhea and infant mortality in developing countries. Given the rise of antibiotic resistance worldwide, there is an urgent need for the development of new preventive strategies. Among them, a promising approach is the use of probiotics. Although many studies, mostly performed under piglet digestive conditions, have shown the beneficial effects of probiotics on ETEC by interfering with their survival, virulence or adhesion to mucosa, underlying mechanisms remain unclear. This review describes ETEC pathogenesis, its modulation by human gastrointestinal cues as well as novel preventive strategies with a particular emphasis on probiotics. The potential of in vitro models simulating human digestion in elucidating probiotic mode of action will be discussed.
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Affiliation(s)
- Charlène Roussel
- Clermont Université, Université d'Auvergne, Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, 63000 Clermont-Ferrand, France.,Cmet, Center for Microbial Ecology & Technology, Ghent University, 9000 Ghent, Belgium
| | - Adeline Sivignon
- Clermont Université, UMR 1071 INSERM/Université d'Auvergne, Clermont-Ferrand, France INRA, Unité Sous Contrat 2018, Clermont-Ferrand, France
| | - Tom Van de Wiele
- Cmet, Center for Microbial Ecology & Technology, Ghent University, 9000 Ghent, Belgium
| | - Stéphanie Blanquet-Diot
- Clermont Université, Université d'Auvergne, Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, 63000 Clermont-Ferrand, France
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16
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Dubreuil JD, Isaacson RE, Schifferli DM. Animal Enterotoxigenic Escherichia coli. EcoSal Plus 2016; 7:10.1128/ecosalplus.ESP-0006-2016. [PMID: 27735786 PMCID: PMC5123703 DOI: 10.1128/ecosalplus.esp-0006-2016] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 12/13/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is the most common cause of E. coli diarrhea in farm animals. ETEC are characterized by the ability to produce two types of virulence factors: adhesins that promote binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion. The best-characterized adhesins are expressed in the context of fimbriae, such as the F4 (also designated K88), F5 (K99), F6 (987P), F17, and F18 fimbriae. Once established in the animal small intestine, ETEC produce enterotoxin(s) that lead to diarrhea. The enterotoxins belong to two major classes: heat-labile toxins that consist of one active and five binding subunits (LT), and heat-stable toxins that are small polypeptides (STa, STb, and EAST1). This review describes the disease and pathogenesis of animal ETEC, the corresponding virulence genes and protein products of these bacteria, their regulation and targets in animal hosts, as well as mechanisms of action. Furthermore, vaccines, inhibitors, probiotics, and the identification of potential new targets by genomics are presented in the context of animal ETEC.
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Affiliation(s)
- J Daniel Dubreuil
- Faculté de Médecine Vétérinaire, Université de Montréal, Québec J2S 7C6, Canada
| | - Richard E Isaacson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108
| | - Dieter M Schifferli
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
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17
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Shin J, Yoon KB, Jeon DY, Oh SS, Oh KH, Chung GT, Kim SW, Cho SH. Consecutive Outbreaks of Enterotoxigenic Escherichia coli O6 in Schools in South Korea Caused by Contamination of Fermented Vegetable Kimchi. Foodborne Pathog Dis 2016; 13:535-543. [PMID: 27557346 DOI: 10.1089/fpd.2016.2147] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Two outbreaks of gastroenteritis occurred in South Korea, affecting a middle school in the Jeollanam-do province in 2013 (Outbreak 1) and 10 schools in the Incheon province in 2014 (Outbreak 2). We investigated the outbreaks to identify the pathogen and mode of transmission. METHODS A retrospective cohort study was conducted in the Outbreak 1; and case-control studies were performed for the Outbreak 2. Samples from students, environments, and preserved food items were collected and pulsed-field gel electrophoresis (PFGE) was conducted to identify strains of pathogen. RESULTS We identified 167 and 1022 students who met the case definition (≥3 loose stools in any 24-h period) in the Outbreaks 1 and 2, respectively. The consumption of cabbage kimchi and young radish kimchi were significantly associated with the illness. Adjusted odds ratios of kimchi were 2.62-11.74. In the Outbreak 1, cabbage kimchi was made and consumed in the school restaurant and in the Outbreak 2, young radish kimchi was supplied by food company X and distributed to all the 10 schools in the Incheon province. Enterotoxigenic Escherichia coli (ETEC) O6 was isolated from fecal samples in 375 cases (33.9%) and from kimchi samples. PFGE patterns of the outbreak strains isolated from cases and food were indistinguishable in each outbreak. CONCLUSION The suspected food vehicle in these two consecutive outbreaks was kimchi contaminated with ETEC O6. We recommend continued monitoring and stricter sanitation requirements for the food supply process in Korea, especially in relation to kimchi.
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Affiliation(s)
- Jaeseung Shin
- 1 Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention , Cheongju, Republic of Korea
| | - Ki-Bok Yoon
- 2 Division of Microbiology, Jeollanam-do Institute of Public Health and Environment , Gwangju, Republic of Korea
| | - Doo-Young Jeon
- 2 Division of Microbiology, Jeollanam-do Institute of Public Health and Environment , Gwangju, Republic of Korea
| | - Sung-Suk Oh
- 3 Division of Microbiology, Incheon Research Institute of Public Health and Environment , Incheon, Republic of Korea
| | - Kyung-Hwan Oh
- 4 Division of Enteric Diseases, Center for Infectious Diseases, Korea National Institute of Health , Cheongju, Republic of Korea
| | - Gyung Tae Chung
- 4 Division of Enteric Diseases, Center for Infectious Diseases, Korea National Institute of Health , Cheongju, Republic of Korea
| | - Seung Woo Kim
- 1 Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention , Cheongju, Republic of Korea
| | - Seung-Hak Cho
- 4 Division of Enteric Diseases, Center for Infectious Diseases, Korea National Institute of Health , Cheongju, Republic of Korea
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18
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Joffré E, von Mentzer A, Svennerholm AM, Sjöling Å. Identification of new heat-stable (STa) enterotoxin allele variants produced by human enterotoxigenic Escherichia coli (ETEC). Int J Med Microbiol 2016; 306:586-594. [PMID: 27350142 DOI: 10.1016/j.ijmm.2016.05.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 05/25/2016] [Accepted: 05/25/2016] [Indexed: 11/16/2022] Open
Abstract
We describe natural variants of the heat stable toxin (STa) produced by enterotoxigenic Escherichia coli (ETEC) isolates collected worldwide. Previous studies of ETEC isolated from human diarrheal cases have reported the existence of three natural STa gene variants estA1, estA2 and estA3/4 where the first variant encodes STp (porcine, bovine, and human origin) and the two latter ones encode STh (human origin). We identified STa sequences by BLASTn and profiled ST amino acid polymorphisms in a collection of 118 clinical ETEC isolates from children and adults from Asia, Africa and, Latin America that were characterized by whole genome sequencing. Three novel variants of STp and STh were found and designated STa5 and STa6, and STa7, respectively. Presence of glucose significantly decreased the production of STh and STp toxin variants (p<0.05) as well as downregulated the gene expression (STh: p<0.001, STp: p<0.05). We found that the ETEC isolates producing the most common STp variant, STa5, co-expressed coli surface antigen CS6 and was significantly associated with disease in adults in this data set (p<0.001). Expression of mature STa5 peptide as well as gene expression of tolC, involved in ST secretion, increased in response to bile (p<0.05). ETEC expressing the common STh variant STa3/4 was associated with disease in children (p<0.05). The crp gene, that positively regulate estA3/4 encoding STa3/4, and estA3/4 itself had decreased transcriptional levels in presence of bile. Since bile levels in the intestine are lower in children than adults, these results may suggest differences in pathogenicity of ETEC in children and adult populations.
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Affiliation(s)
- Enrique Joffré
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Institute of Molecular Biology and Biotechnology, Universidad Mayor de San Andrés, La Paz, Bolivia.
| | - Astrid von Mentzer
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; The Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Åsa Sjöling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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19
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Joffré E, Sjöling Å. The LT1 and LT2 variants of the enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LT) are associated with major ETEC lineages. Gut Microbes 2016; 7:75-81. [PMID: 26939855 PMCID: PMC4856455 DOI: 10.1080/19490976.2015.1127480] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The heat-labile toxin (LT) is one of the major virulence factors of enterotoxigenic Escherichia coli (ETEC). We recently described that 20 polymorphic LT variants are present in ETEC strains isolated globally. Two of the variants, LT1 and LT2, are particularly common and we found that they were associated with clonal ETEC lineages that express the colonization factors (CFs), CFA/I, CS1+CS3, CS2+CS3, and CS5+CS6. ETEC expressing these CFs are frequently found among ETEC strains isolated from cases with diarrhea. ETEC expressing the colonization factors CS1+CS3, and CS2+CS3 are found in 2 discrete clonal lineages and express the LT1 variant and heat stable toxin (STh). Although they clearly are virulent they neither produce, nor secrete, high amounts of LT toxin. On the other hand ETEC strains expressing LT, STh, CFA/I and LT, STh, CS5+CS6, carry the LT2 variant and produce and secrete significantly more LT toxin. Despite differences in toxin production, LT1 and LT2 are found in ETEC lineages that have managed to spread globally confirming that these variants are important for ETEC virulence.
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Affiliation(s)
- Enrique Joffré
- Department of Microbiology and Immunology; Sahlgrenska Academy; University of Gothenburg; Göteborg, Sweden,Institute of Molecular Biology and Biotechnology; Universidad Mayor de San Andrés; La Paz, Bolivia,Department of Microbiology; Tumor and Cell Biology; Karolinska Institutet; Stockholm, Sweden
| | - Åsa Sjöling
- Department of Microbiology; Tumor and Cell Biology; Karolinska Institutet; Stockholm, Sweden
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20
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Gonzales-Siles L, Sjöling Å. The different ecological niches of enterotoxigenic Escherichia coli. Environ Microbiol 2015; 18:741-51. [PMID: 26522129 PMCID: PMC4982042 DOI: 10.1111/1462-2920.13106] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/30/2015] [Accepted: 10/26/2015] [Indexed: 12/17/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a water and food-borne pathogen that infects the small intestine of the human gut and causes diarrhoea. Enterotoxigenic E. coli adheres to the epithelium by means of colonization factors and secretes two enterotoxins, the heat labile toxin and/or the heat stable toxin that both deregulate ion channels and cause secretory diarrhoea. Enterotoxigenic E. coli as all E. coli, is a versatile organism able to survive and grow in different environments. During transmission and infection, ETEC is exposed to various environmental cues that have an impact on survivability and virulence. The ability to cope with exposure to different stressful habitats is probably shaping the pool of virulent ETEC strains that cause both endemic and epidemic infections. This review will focus on the ecology of ETEC in its different habitats and interactions with other organisms as well as abiotic factors.
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Affiliation(s)
- Lucia Gonzales-Siles
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Åsa Sjöling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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21
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Identification of Novel Components Influencing Colonization Factor Antigen I Expression in Enterotoxigenic Escherichia coli. PLoS One 2015; 10:e0141469. [PMID: 26517723 PMCID: PMC4627747 DOI: 10.1371/journal.pone.0141469] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 10/08/2015] [Indexed: 11/19/2022] Open
Abstract
Colonization factors (CFs) mediate early adhesion of Enterotoxigenic Escherichia coli (ETEC) in the small intestine. Environmental signals including bile, glucose, and contact with epithelial cells have previously been shown to modulate CF expression in a strain dependent manner. To identify novel components modulating CF surface expression, 20 components relevant to the intestinal environment were selected for evaluation. These included mucin, bicarbonate, norepinephrine, lincomycin, carbon sources, and cations. Effects of individual components on surface expression of the archetype CF, CFA/I, were screened using a fractional factorial Hadamard matrix incorporating 24 growth conditions. As most CFs agglutinate erythrocytes, surface expression was evaluated by mannose resistant hemagglutination. Seven components, including porcine gastric mucin, lincomycin, glutamine, and glucose were found to induce CFA/I surface expression in vitro in a minimal media while five others were inhibitory, including leucine and 1,10-phenanthroline. To further explore the effect of components positively influencing CFA/I surface expression, a response surface methodology (RSM) was designed incorporating 36 growth conditions. The optimum concentration for each component was identified, thereby generating a novel culture media, SP1, for CFA/I expression. CFs closely related to CFA/I, including CS4 and CS14 were similarly induced in SP1 media. Other epidemiologically relevant CFs were also induced when compared to the level obtained in minimal media. These results indicate that although CF surface expression is complex and highly variable among strains, the CF response can be predicted for closely related strains. A novel culture media inducing CFs in the CF5a group was successfully identified. In addition, mucin was found to positively influence CF expression in strains expressing either CFA/I or CS1 and CS3, and may function as a common environmental cue.
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22
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IscR Regulates Synthesis of Colonization Factor Antigen I Fimbriae in Response to Iron Starvation in Enterotoxigenic Escherichia coli. J Bacteriol 2015; 197:2896-907. [PMID: 26124243 DOI: 10.1128/jb.00214-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/23/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Iron availability functions as an environmental cue for enteropathogenic bacteria, signaling arrival within the human host. As enterotoxigenic Escherichia coli (ETEC) is a major cause of human diarrhea, the effect of iron on ETEC virulence factors was evaluated here. ETEC pathogenicity is directly linked to production of fimbrial colonization factors and secretion of heat-labile enterotoxin (LT) and/or heat-stable enterotoxin (ST). Efficient colonization of the small intestine further requires at least the flagellin binding adhesin EtpA. Under iron starvation, production of the CFA/I fimbriae was increased in the ETEC H10407 prototype strain. In contrast, LT secretion was inhibited. Furthermore, under iron starvation, gene expression of the cfa (CFA/I) and etp (EtpBAC) operons was induced, whereas transcription of toxin genes was either unchanged or repressed. Transcriptional reporter fusion experiments focusing on the cfa operon further showed that iron starvation stimulated cfaA promoter activity in ETEC, indicating that the impact of iron on CFA/I production was mediated by transcriptional regulation. Evaluation of cfaA promoter activity in heterologous E. coli single mutant knockout strains identified IscR as the regulator responsible for inducing cfa fimbrial gene expression in response to iron starvation, and this was confirmed in an ETEC ΔiscR strain. The global iron response regulator, Fur, was not implicated. IscR binding sites were identified in silico within the cfaA promoter and fixation confirmed by DNase I footprinting, indicating that IscR directly binds the promoter region to induce CFA/I. IMPORTANCE Pathogenic enterobacteria modulate expression of virulence genes in response to iron availability. Although the Fur transcription factor represents the global regulator of iron homeostasis in Escherichia coli, we show that several ETEC virulence factors are modulated by iron, with expression of the major fimbriae under the control of the iron-sulfur cluster regulator, IscR. Furthermore, we demonstrate that the apo form of IscR, lacking an Fe-S cluster, is able to directly fix the corresponding promoter region. These results provide further evidence implicating IscR in bacterial virulence and suggest that IscR may represent a more general regulator mediating the iron response in enteropathogens.
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23
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Relationship between heat-labile enterotoxin secretion capacity and virulence in wild type porcine-origin enterotoxigenic Escherichia coli strains. PLoS One 2015; 10:e0117663. [PMID: 25768732 PMCID: PMC4358887 DOI: 10.1371/journal.pone.0117663] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 12/30/2014] [Indexed: 02/07/2023] Open
Abstract
Heat-labile enterotoxin (LT) is an important virulence factor secreted by some strains of enterotoxigenic Escherichia coli (ETEC). The prototypic human-origin strain H10407 secretes LT via a type II secretion system (T2SS). We sought to determine the relationship between the capacity to secrete LT and virulence in porcine-origin wild type (WT) ETEC strains. Sixteen WT ETEC strains isolated from cases of severe diarrheal disease were analyzed by GM1ganglioside enzyme-linked immunosorbent assay to measure LT concentrations in culture supernatants. All strains had detectable LT in supernatants by 2 h of culture and 1 strain, which was particularly virulent in gnotobiotic piglets (3030-2), had the highest LT secretion level all porcine-origin WT strains tested (P<0.05). The level of LT secretion (concentration in supernatants at 6-h culture) explained 92% of the variation in time-to-a-moribund-condition (R2 = 0.92, P<0.0001) in gnotobiotic piglets inoculated with either strain 3030-2, or an ETEC strain of lesser virulence (2534-86), or a non-enterotoxigenic WT strain (G58-1). All 16 porcine ETEC strains were positive by PCR analysis for the T2SS genes, gspD and gspK, and bioinformatic analysis of 4 porcine-origin strains for which complete genomic sequences were available revealed a T2SS with a high degree of homology to that of H10407. Maximum Likelihood phylogenetic trees constructed using T2SS genes gspC, gspD, gspE and homologs showed that strains 2534-86 and 3030-2 clustered together in the same clade with other porcine-origin ETEC strains in the database, UMNK88 and UMN18. Protein modeling of the ATPase gene (gspE) further revealed a direct relationship between the predicted ATP-binding capacities and LT secretion levels as follows: H10407, -8.8 kcal/mol and 199 ng/ml; 3030-2, -8.6 kcal/mol and 133 ng/ml; and 2534-86, -8.5 kcal/mol and 80 ng/ml. This study demonstrated a direct relationship between predicted ATP-binding capacity of GspE and LT secretion, and between the latter and virulence.
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24
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Wyrsch E, Roy Chowdhury P, Abraham S, Santos J, Darling AE, Charles IG, Chapman TA, Djordjevic SP. Comparative genomic analysis of a multiple antimicrobial resistant enterotoxigenic E. coli O157 lineage from Australian pigs. BMC Genomics 2015; 16:165. [PMID: 25888127 PMCID: PMC4384309 DOI: 10.1186/s12864-015-1382-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 02/23/2015] [Indexed: 01/01/2023] Open
Abstract
Background Enterotoxigenic Escherichia coli (ETEC) are a major economic threat to pig production globally, with serogroups O8, O9, O45, O101, O138, O139, O141, O149 and O157 implicated as the leading diarrhoeal pathogens affecting pigs below four weeks of age. A multiple antimicrobial resistant ETEC O157 (O157 SvETEC) representative of O157 isolates from a pig farm in New South Wales, Australia that experienced repeated bouts of pre- and post-weaning diarrhoea resulting in multiple fatalities was characterized here. Enterohaemorrhagic E. coli (EHEC) O157:H7 cause both sporadic and widespread outbreaks of foodborne disease, predominantly have a ruminant origin and belong to the ST11 clonal complex. Here, for the first time, we conducted comparative genomic analyses of two epidemiologically-unrelated porcine, disease-causing ETEC O157; E. coli O157 SvETEC and E. coli O157:K88 734/3, and examined their phylogenetic relationship with EHEC O157:H7. Results O157 SvETEC and O157:K88 734/3 belong to a novel sequence type (ST4245) that comprises part of the ST23 complex and are genetically distinct from EHEC O157. Comparative phylogenetic analysis using PhyloSift shows that E. coli O157 SvETEC and E. coli O157:K88 734/3 group into a single clade and are most similar to the extraintestinal avian pathogenic Escherichia coli (APEC) isolate O78 that clusters within the ST23 complex. Genome content was highly similar between E. coli O157 SvETEC, O157:K88 734/3 and APEC O78, with variability predominantly limited to laterally acquired elements, including prophages, plasmids and antimicrobial resistance gene loci. Putative ETEC virulence factors, including the toxins STb and LT and the K88 (F4) adhesin, were conserved between O157 SvETEC and O157:K88 734/3. The O157 SvETEC isolate also encoded the heat stable enterotoxin STa and a second allele of STb, whilst a prophage within O157:K88 734/3 encoded the serum survival gene bor. Both isolates harbor a large repertoire of antibiotic resistance genes but their association with mobile elements remains undetermined. Conclusions We present an analysis of the first draft genome sequences of two epidemiologically-unrelated, pathogenic ETEC O157. E. coli O157 SvETEC and E. coli O157:K88 734/3 belong to the ST23 complex and are phylogenetically distinct to EHEC O157 lineages that reside within the ST11 complex. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1382-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ethan Wyrsch
- The ithree institute, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
| | - Piklu Roy Chowdhury
- The ithree institute, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia. .,NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Private Bag 4008, Narellan, NSW, 2567, Australia.
| | - Sam Abraham
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Private Bag 4008, Narellan, NSW, 2567, Australia. .,School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, South Australia, 5371, Australia.
| | - Jerran Santos
- The ithree institute, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
| | - Aaron E Darling
- The ithree institute, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
| | - Ian G Charles
- The ithree institute, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
| | - Toni A Chapman
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Private Bag 4008, Narellan, NSW, 2567, Australia.
| | - Steven P Djordjevic
- The ithree institute, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
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25
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Allele variants of enterotoxigenic Escherichia coli heat-labile toxin are globally transmitted and associated with colonization factors. J Bacteriol 2014; 197:392-403. [PMID: 25404692 DOI: 10.1128/jb.02050-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a significant cause of morbidity and mortality in the developing world. ETEC-mediated diarrhea is orchestrated by heat-labile toxin (LT) and heat-stable toxins (STp and STh), acting in concert with a repertoire of more than 25 colonization factors (CFs). LT, the major virulence factor, induces fluid secretion after delivery of a monomeric ADP-ribosylase (LTA) and its pentameric carrier B subunit (LTB). A study of ETEC isolates from humans in Brazil reported the existence of natural LT variants. In the present study, analysis of predicted amino acid sequences showed that the LT amino acid polymorphisms are associated with a geographically and temporally diverse set of 192 clinical ETEC strains and identified 12 novel LT variants. Twenty distinct LT amino acid variants were observed in the globally distributed strains, and phylogenetic analysis showed these to be associated with different CF profiles. Notably, the most prevalent LT1 allele variants were correlated with major ETEC lineages expressing CS1 + CS3 or CS2 + CS3, and the most prevalent LT2 allele variants were correlated with major ETEC lineages expressing CS5 + CS6 or CFA/I. LTB allele variants generally exhibited more-stringent amino acid sequence conservation (2 substitutions identified) than LTA allele variants (22 substitutions identified). The functional impact of LT1 and LT2 polymorphisms on virulence was investigated by measuring total-toxin production, secretion, and stability using GM1-enzyme-linked immunosorbent assays (GM1-ELISA) and in silico protein modeling. Our data show that LT2 strains produce 5-fold more toxin than LT1 strains (P < 0.001), which may suggest greater virulence potential for this genetic variant. Our data suggest that functionally distinct LT-CF variants with increased fitness have persisted during the evolution of ETEC and have spread globally.
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26
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Abstract
Enterotoxigenic Escherichia coli is frequently associated with travelers' diarrhea and is a leading cause of infant and childhood mortality in developing countries. Disease is dependent upon the orchestrated expression of enterotoxins, flexible adhesive pili, and other virulence factors. Both the heat-labile (LT) and heat-stable (ST-H) enterotoxins are regulated at the level of transcription by cAMP-receptor protein which represses the expression of LT while activating expression of ST-H. The expression of many different serotypes of adhesive pili is regulated by Rns, a member of the AraC family that represents a subgroup of conserved virulence regulators from several enteric pathogens. These Rns-like regulators recognize similar DNA binding sites, and a compiled sequence logo suggests they may bind DNA through both major and minor groove interactions. These regulators are also tempting targets for novel therapeutics because they play pivotal roles during infection. To that end, high-throughput screens have begun to identify compounds that inhibit the activity of these regulators, predominately by interfering with DNA binding.
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Affiliation(s)
- George P Munson
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, P.O. Box 016960 (R-138), Miami, FL, 33101, USA,
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27
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İnal S, Okyay GU, Ulu MS, Kıdır V, Altuntaş A, Ahsen A, Ünverdi S, Akoğlu H, Yüksel Ş, Duranay M, Sezer MT. The effect of biocompatible peritoneal dialysis solutions on neutrophil to lymphocyte ratio. Ren Fail 2014; 36:1239-43. [PMID: 25009984 DOI: 10.3109/0886022x.2014.937662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION Long-term exposure to dialysis solutions is an important contributor to the ongoing inflammatory process in peritoneal dialysis (PD) patients. Some studies have shown amelioration of this adverse effect with biocompatible solutions. We aimed to compare the neutrophil-to-lymphocyte (N/L) ratio in PD patients using biocompatible and standard solutions and to find out the association between N/L ratio and peritonitis indices. MATERIALS AND METHODS This was a cross-sectional, multicenter study involving 120 prevalent PD patients. Seventy-one patients (59%) were using biocompatible solutions and 49 patients (41%) were using standard solutions. From blood samples, N/L ratio and platelet-to-lymphocyte ratio were calculated and mean platelet volume, erythrocyte sedimentation rate and hs-CRP values were detected. Data regarding the peritonitis rate and time to first peritonitis episode were also recorded. RESULTS Biocompatible and standard groups were similar regarding age and gender. N/L ratio and hs-CRP levels have been found significantly higher in patients using biocompatible solutions (3.75 ± 1.50 vs. 3.27 ± 1.3, p = 0.04 and 3.2 ± 2.5 vs. 1.8 ± 2.0, p < 0.01, respectively). Peritonitis rates and time to the first peritonitis episode were found similar in patients using both types of solutions (0.23 ± 0.35 vs. 0.27 ± 0.32, p = 0.36 and 32.8 ± 35.8 vs. 21.5 ± 26.9 months, p = 0.16, respectively). DISCUSSION N/L ratio was significantly higher in biocompatible solution users in parallel to hs-CRP levels, so biocompatible solutions seem to be related with increased inflammation in PD patients. Although we cannot make a certain explanation, we assume that there may be an association between acidity of the peritoneal content and virulence of microorganisms.
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Affiliation(s)
- Salih İnal
- Department of Internal Medicine, Division of Nephrology, Süleyman Demirel University Medical School , Isparta , Turkey
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