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Jiang F, Yang Y, Mao Z, Cai W, Li G. ArcA positively regulates the expression of virulence genes and contributes to virulence of porcine Shiga toxin-producing enterotoxigenic Escherichia coli. Microbiol Spectr 2023; 11:e0152523. [PMID: 37916813 PMCID: PMC10714933 DOI: 10.1128/spectrum.01525-23] [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: 04/12/2023] [Accepted: 10/09/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) cause severe diarrhea in humans and animals, leading to death and huge economic loss worldwide. Thus, elucidation of ETEC's pathogenic mechanisms will provide powerful data for the discovery of drugs serving as prevention or therapeutics against ETEC-caused diarrheal diseases. Here, we report that ArcA plays an essential role in the pathogenicity and virulence regulation in ETEC by positively regulating the expression of several key virulence factors including F18 fimbriae, heat-labile and heat-stable toxins, Shiga toxin 2e, and hemolysin, under microaerobic conditions and in vivo. Moreover, we found that positive regulation of several virulence genes by ArcA requires a global repressor H-NS (histone-like nucleoid structuring), implying that ArcA may exert positive effects by antagonizing H-NS. Collectively, our data established a key role for ArcA in the pathogenicity of porcine ETEC and ETEC strains isolated from human infections. Moreover, our work reveals another layer of regulation in relation to oxygen control of virulence factors in ETEC.
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Affiliation(s)
- Fengwei Jiang
- State Key Laboratory for Animal Disease Control and Prevention, 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, Iowa, USA
| | - Yan Yang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhao Mao
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Wentong Cai
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ganwu Li
- State Key Laboratory for Animal Disease Control and Prevention, 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, Iowa, USA
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Lu X, Zhang M, Ma Y, Li G, Zhao X, Qian W. Protective effect of Limosilactobacillus reuteri-fermented yogurt on mouse intestinal barrier injury induced by enterotoxigenic Escherichia coli. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2023; 103:7494-7505. [PMID: 37411001 DOI: 10.1002/jsfa.12836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 06/25/2023] [Accepted: 07/07/2023] [Indexed: 07/08/2023]
Abstract
BACKGROUND Enterotoxigenic Escherichia coli (ETEC) is a pathogen that causes traveler's diarrhea, for which an effective vaccine is lacking. Previous studies showed that Limosilactobacillus reuteri could inhibit E. coli, effectively increase the expression of its tight junction protein, and reduce the adhesion of ETEC to the intestinal epithelial Caco-2 cell line. In this study, three kinds of yogurt with different starter cultures were first prepared: Lm. reuteri yogurt (fermented by Lm. reuteri alone), traditional yogurt (fermented by Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus at a ratio of 1:1) and mixed yogurt (fermented by Lm. reuteri, S. thermophilus and L. delbrueckii subsp. bulgaricus at a ratio of 1:1:1). The physiological properties, oxidative stress, intestinal barrier function, tight junction protein, pathological conditions and intestinal microbiota composition were investigated. RESULTS The data showed that Lm. reuteri-fermented yogurt pregavage could effectively alleviate the intestinal barrier impairment caused by ETEC in mice. It alleviated intestinal villus shortening and inflammatory cell infiltration, decreased plasma diamine oxidase concentration and increased claudin-1 and occludin expression in the jejunum of ETEC-infected mice. In addition, Lm. reuteri-fermented yogurt significantly reduced the ETEC load in fecal samples, reversed the increase in Pseudomonadota abundance and decreased Bacteroidota abundance caused by ETEC infection. Furthermore, the composition of the intestinal microbiota could maintain a stable state similar to that in healthy mice. CONCLUSION These findings indicate that Lm. reuteri-fermented yogurt could alleviate intestinal barrier damage, inhibit ETEC growth and maintain the stability of the intestinal microbiota during ETEC infection. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Xi Lu
- School of Food Science and Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Mingxin Zhang
- School of Food Science and Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Yuzhe Ma
- School of Food Science and Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Guohua Li
- School of Food Science and Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Xin Zhao
- School of Food Science and Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Weisheng Qian
- Tangdu Hospital, Air Force Military Medical University, Xi'an, China
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Zhuo W, Zhao Y, Zhao X, Yao Z, Qiu X, Huang Y, Li H, Shen J, Zhu Z, Li T, Li S, Huang Q, Zhou R. Enteropathogenic Escherichia coli is a predominant pathotype in healthy pigs in Hubei Province of China. J Appl Microbiol 2023; 134:lxad260. [PMID: 37962953 DOI: 10.1093/jambio/lxad260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/29/2023] [Accepted: 11/13/2023] [Indexed: 11/16/2023]
Abstract
AIM This study aims to investigate the prevalence of intestinal pathogenic Escherichia coli (InPEC) in healthy pig-related samples and evaluate the potential virulence of the InPEC strains. METHODS AND RESULTS A multiplex PCR method was established to identify different pathotypes of InPEC. A total of 800 rectal swab samples and 296 pork samples were collected from pig farms and slaughterhouses in Hubei province, China. From these samples, a total of 21 InPEC strains were isolated, including 19 enteropathogenic E. coli (EPEC) and 2 shiga toxin-producing E. coli (STEC) strains. By whole-genome sequencing and in silico typing, it was shown that the sequence types and serotypes were diverse among the strains. Antimicrobial susceptibility assays showed that 90.48% of the strains were multi-drug resistant. The virulence of the strains was first evaluated using the Galleria mellonella larvae model, which showed that most of the strains possessed medium to high pathogenicity. A moderately virulent EPEC isolate was further selected to characterize its pathogenicity using a mouse model, which suggested that it could cause significant diarrhea. Bioluminescence imaging (BLI) was then used to investigate the colonization dynamics of this EPEC isolate, which showed that the EPEC strain could colonize the mouse cecum for up to 5 days.
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Affiliation(s)
- Wenxiao Zhuo
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Yang Zhao
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Xianglin Zhao
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhiming Yao
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiuxiu Qiu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Yaxue Huang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Huaixia Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Jing Shen
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhihao Zhu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Tingting Li
- Hubei Animal Disease Prevention and Control Center, Wuhan 430070, China
| | - Shaowen Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Qi Huang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, College of Veterinary Medicine, Wuhan 430070, China
- International Research Center for Animal Disease (Ministry of Science & Technology of China), College of Veterinary Medicine, Wuhan 430070, China
| | - Rui Zhou
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, College of Veterinary Medicine, Wuhan 430070, China
- International Research Center for Animal Disease (Ministry of Science & Technology of China), College of Veterinary Medicine, Wuhan 430070, China
- The HZAU-HVSEN Research Institute, Wuhan 430042, China
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Hollifield IE, Motyka NI, Fernando KA, Bitoun JP. Heat-Labile Enterotoxin Decreases Macrophage Phagocytosis of Enterotoxigenic Escherichia coli. Microorganisms 2023; 11:2121. [PMID: 37630681 PMCID: PMC10459231 DOI: 10.3390/microorganisms11082121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Enterotoxigenic E. coli (ETEC) are endemic in low-resource settings and cause robust secretory diarrheal disease in children less than five years of age. ETEC cause secretory diarrhea by producing the heat-stable (ST) and/or heat-labile (LT) enterotoxins. Recent studies have shown that ETEC can be carried asymptomatically in children and adults, but how ETEC subvert mucosal immunity to establish intestinal residency remains unclear. Macrophages are innate immune cells that can be exploited by enteric pathogens to evade mucosal immunity, so we interrogated the ability of ETEC and other E. coli pathovars to survive within macrophages. Using gentamicin protection assays, we show that ETEC H10407 is phagocytosed more readily than other ETEC and non-ETEC isolates. Furthermore, we demonstrate that ETEC H10407, at high bacterial burdens, causes nitrite accumulation in macrophages, which is indicative of a proinflammatory macrophage nitric oxide killing response. However, at low bacterial burdens, ETEC H10407 remains viable within macrophages for an extended period without nitrite accumulation. We demonstrate that LT, but not ST, intoxication decreases the number of ETEC phagocytosed by macrophages. Furthermore, we now show that macrophages exposed simultaneously to LPS and LT produce IL-33, which is a cytokine implicated in promoting macrophage alternative activation, iron recycling, and intestinal repair. Lastly, iron restriction using deferoxamine induces IL-33 receptor (IL-33R) expression and allows ETEC to escape macrophages. Altogether, these data demonstrate that LT provides ETEC with the ability to decrease the perceived ETEC burden and suppresses the initiation of inflammation. Furthermore, these data suggest that host IL-33/IL-33R signaling may augment pathways that promote iron restriction to facilitate ETEC escape from macrophages. These data could help explain novel mechanisms of immune subversion that may contribute to asymptomatic ETEC carriage.
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Affiliation(s)
| | | | | | - Jacob P. Bitoun
- Department of Microbiology and Immunology, Tulane University School of Medicine, 1430 Tulane Avenue, #8638, New Orleans, LA 70112, USA; (I.E.H.); (N.I.M.); (K.A.F.)
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Abstract
In order for successful fecal-oral transmission, enteric bacterial pathogens have to successfully compete with the intestinal microbiota and reach high concentrations during infection. Vibrio cholerae requires cholera toxin (CT) to cause diarrheal disease, which is thought to promote the fecal-oral transmission of the pathogen. Besides inducing diarrheal disease, the catalytic activity of CT also alters host intestinal metabolism, which promotes the growth of V. cholerae during infection through the acquisition of host-derived nutrients. Furthermore, recent studies have found that CT-induced disease activates a niche-specific suite of V. cholerae genes during infection, some of which may be important for fecal-oral transmission of the pathogen. Our group is currently exploring the concept that CT-induced disease promotes the fecal-oral transmission of V. cholerae by modulating both host and pathogen metabolism. Furthermore, the role of the intestinal microbiota in pathogen growth and transmission during toxin-induced disease merits further investigation. These studies open the door to investigating whether other bacterial toxins also enhance pathogen growth and transmission during infection, which may shed light on the design of novel therapeutics for intervention or prevention of diarrheal diseases.
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Affiliation(s)
- Claire M. L. Chapman
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, USA
| | - Andrew Kapinos
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, USA
| | - Fabian Rivera-Chávez
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, USA
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Heat-Stable Enterotoxin Secretions Assessed via ICP-MS Reveal Iron-Mediated Regulation of Virulence in CFA/I- and CS6-Expressing ETEC Isolates. Cells 2023; 12:cells12040567. [PMID: 36831233 PMCID: PMC9954033 DOI: 10.3390/cells12040567] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/11/2023] [Accepted: 02/03/2023] [Indexed: 02/12/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are a significant cause of childhood diarrhea in low-resource settings. ETEC are defined by the production of heat-stable enterotoxin (ST) and/or heat-labile enterotoxin (LT), which alter intracellular cyclic nucleotide signaling and cause the secretion of water and electrolytes into the intestinal lumen. ETEC take cues from chemicals (e.g., glycans, bile salts, and solutes) that may be liberated following enterotoxin activity to recognize entrance into the host. ETEC then alter the expression of surface adhesins called colonization factors (CFs) to attach to the intestinal epithelium, proliferate, and cause disease. Here, we used an in vivo model of oral ST intoxication to determine its impact on luminal ion concentrations via ICP-MS. We also used functional assays, including Western blots, qPCR, and toxin activity assays, to assess the impact of luminal ion flux on CF and toxin expression. Finally, we assessed ETEC strains with CFs CFA/I or CS6 in a streptomycin mouse model of ETEC colonization. ST causes rapid and significant increases in luminal chloride but significant decreases in luminal magnesium and iron. We confirmed that increased sodium chloride suppresses CFA/I production in ETEC H10407 but does not affect CS6 production in ETEC 214-4. CFA/I production in ETEC H10407 is increased when magnesium becomes limiting, although it does not affect CS6 production in ETEC 214-4. Iron restriction via deferoxamine induces CFA/I expression in ETEC H10407 but not CS6 expression in ETEC 214-4. We demonstrate that ST production is suppressed via iron restriction in H10407, 214-4, and over 50 other ETEC clinical isolates. Lastly, we demonstrate that the iron restriction of mice using oral deferoxamine pre-treatment extends the duration of ETEC H10407 (CFA/I+) fecal shedding while accelerating ETEC 214-4 (CS6+) fecal shedding. Combined, these data suggest that enterotoxins modulate luminal ion flux to influence ETEC virulence including toxin and CF production.
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Dual-Use Vaccine for Diarrhoeal Diseases: Cross-Protective Immunogenicity of a Cold-Chain-Free, Live-Attenuated, Oral Cholera Vaccine against Enterotoxigenic Escherichia coli (ETEC) Challenge in BALB/c Mice. Vaccines (Basel) 2022; 10:vaccines10122161. [PMID: 36560571 PMCID: PMC9787504 DOI: 10.3390/vaccines10122161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
In low- and middle-income countries, diarrhoeal diseases are the second most common cause of mortality in children, mainly caused by enterotoxin-producing bacteria, such as Shigella, Vibrio, Salmonella, and Escherichia coli. Cholera and traveller's diarrhoea are caused by Vibrio cholerae (O1 and O139 serogroups) and enterotoxigenic Escherichia coli (ETEC), respectively. The cholera toxin (CT) produced by V. cholerae and the heat-labile enterotoxin (LT) of ETEC are closely related by structure, function, and the immunological response to them. There is no exclusive vaccine for ETEC; however, cholera vaccines based on the CT-B component elicit a short-term cross-protection against ETEC infection. In this context, the cross-protective efficacy of MyCholTM, a prototype cold-chain-free, live-attenuated, oral cholera vaccine against V. cholerae O139 was evaluated in BALB/c mice. The 100% lethal dose (LD100) of 109 CFU/mL of the ETEC H10407 strain was used for the challenge studies. The mice immunised with MyChol™ survived the challenge by producing anti-CT antibodies, which cross-neutralised the LT toxin with no body weight loss and no sign of diarrhoea. Compared to unimmunised mice, the immunised mice elicited the neutralising antitoxin that markedly decreased ETEC colonisation and fluid accumulation caused by ETEC H10407 in the intestines. The immunised mice recorded higher antibody titres, including anti-CT IgG, anti-LT IgG, anti-CT-B IgG, and anti-LTB IgG. Only a two-fold rise in anti-CT/CT-B/LT/LT-B IgA was recorded in serum samples from immunised mice. No bactericidal antibodies against ETEC H10407 were detected. This investigation demonstrates the safety, immunogenicity, and cross-protective efficacy of MyCholTM against the ETEC H10407 challenge in BALB/c mice.
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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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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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Zhang Y, Tan P, Zhao Y, Ma X. Enterotoxigenic Escherichia coli: intestinal pathogenesis mechanisms and colonization resistance by gut microbiota. Gut Microbes 2022; 14:2055943. [PMID: 35358002 PMCID: PMC8973357 DOI: 10.1080/19490976.2022.2055943] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and travelers in developing countries. ETEC is characterized by the ability to produce major virulence factors including colonization factors (CFs) and enterotoxins, that bind to specific receptors on epithelial cells and induce diarrhea. The gut microbiota is a stable and sophisticated ecosystem that performs a range of beneficial functions for the host, including protection against pathogen colonization. Understanding the pathogenic mechanisms of ETEC and the interaction between the gut microbiota and ETEC represents not only a research need but also an opportunity and challenge to develop precautions for ETEC infection. Herein, this review focuses on recent discoveries about ETEC etiology, pathogenesis and clinical manifestation, and discusses the colonization resistances mediated by gut microbiota, as well as preventative strategies against ETEC with an aim to provide novel insights that can reduce the adverse effect on human health.
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Affiliation(s)
- Yucheng Zhang
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
| | - Peng Tan
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
| | - Ying Zhao
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
| | - Xi Ma
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China,CONTACT Xi Ma State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
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11
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Fleckenstein JM, Sheikh A. Emerging Themes in the Molecular Pathogenesis of Enterotoxigenic Escherichia coli. J Infect Dis 2021; 224:S813-S820. [PMID: 34273153 PMCID: PMC8687053 DOI: 10.1093/infdis/jiab359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are ubiquitous diarrheal pathogens that thrive in areas lacking basic human needs of clean water and sanitation. These genetically plastic organisms cause tremendous morbidity among disadvantaged young children, in the form of both acute diarrheal illness and sequelae of malnutrition and growth impairment. The recent discovery of additional plasmid-encoded virulence factors and elucidation of their critical role in the molecular pathogenesis of ETEC may inform new approaches to the development of broadly protective vaccines. Although the pathogens have been closely linked epidemiologically with nondiarrheal sequelae, these conditions remain very poorly understood. Similarly, while canonical effects of ETEC toxins on cellular signaling promoting diarrhea are clear, emerging data suggest that these toxins may also drive changes in intestinal architecture and associated sequelae. Elucidation of molecular events underlying these changes could inform optimal approaches to vaccines that prevent acute diarrhea and ETEC-associated sequelae.
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Affiliation(s)
- James M Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University in St Louis, School of Medicine, St Louis, Missouri, USA
- Infectious Disease Section, Medicine Service, St Louis Veterans Affairs Health Care System, St Louis, Missouri, USA
| | - Alaullah Sheikh
- Department of Medicine, Division of Infectious Diseases, Washington University in St Louis, School of Medicine, St Louis, Missouri, USA
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12
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Liu M, Yuan B, Jin X, Zhu M, Xu H, Xie G, Wang Z, Zhang X, Xu Z, Li B, Huang Y, Lv Y, Wang W. Citric Acid Promoting B Lymphocyte Differentiation and Anti-epithelial Cells Apoptosis Mediate the Protective Effects of Hermetia illucens Feed in ETEC Induced Piglets Diarrhea. Front Vet Sci 2021; 8:751861. [PMID: 34917669 PMCID: PMC8669560 DOI: 10.3389/fvets.2021.751861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/25/2021] [Indexed: 11/23/2022] Open
Abstract
Newborn piglets are prone to diarrhea after weaning as a result of changes in their environment and feed. Enterotoxigenic Escherichia coli (ETEC) K88 strain is a typical pathogen that causes diarrhea in such stage of piglets. Hermetia illucens larvae are widely used in livestock and poultry production because of their high nutritional value and immunoregulatory effects. This study aimed to evaluate the protective effects of H. illucens feed in protecting against ETEC induced diarrhea in piglets and to unravel the mechanisms of immune modulation and intestinal barrier maintenance. The results showed that after ETEC infection, citric acid in the serum of the groups fed on H. illucens larvae increased significantly, which stimulated macrophages to secrete cytokines that promote B lymphocyte differentiation, ultimately increasing the production of IgA and IgG in serum. Concomitantly, citric acid also had a positive effect on the intestinal barrier damaged due to ETEC infection by inhibiting the production of inflammatory cytokines, reducing the Bcl-2/Bax ratio, and promoting the expression of tight junction proteins. Correlation analysis showed that the increase of citric acid levels might be related to Massilia. Thus, citric acid derived from H. illucens larvae can improve the immune performance of weaned piglets and reduce ETEC-induced damage to the intestinal barrier in weaned piglets.
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Affiliation(s)
- Mingming Liu
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China.,College of Veterinary Medicine, Jilin University, Changchun, China
| | - Boyu Yuan
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xinxin Jin
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Mingqiang Zhu
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Haidong Xu
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Gaijie Xie
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Zifan Wang
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Xue Zhang
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Zhaoyun Xu
- Special Police Academy of Chinese People's Armed Police Force, Beijing, China
| | - Bai Li
- The First Hospital of Jilin University, Changchun, China
| | - Yanhua Huang
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yantao Lv
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Wei Wang
- College of Animal Science & Technology, Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou, China
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13
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Prophylactic Catechin-Rich Green Tea Extract Treatment Ameliorates Pathogenic Enterotoxic Escherichia coli-Induced Colitis. Pathogens 2021; 10:pathogens10121573. [PMID: 34959529 PMCID: PMC8704293 DOI: 10.3390/pathogens10121573] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/26/2021] [Accepted: 11/30/2021] [Indexed: 12/12/2022] Open
Abstract
In this study, we explored the potential beneficial effects of green tea extract (GTE) in a pathogenic Escherichia coli (F18:LT:STa:Stx2e)-induced colitis model. The GTE was standardized with catechin and epigallocatechin-3-gallate content using chromatography analysis. Ten consecutive days of GTE (500 and 1000 mg/kg) oral administration was followed by 3 days of a pathogenic E. coli challenge (1 × 109 CFU/mL). In vitro antibacterial analysis showed that GTE successfully inhibited the growth of pathogenic E. coli, demonstrating over a 3-fold reduction under time- and concentration-dependent conditions. The in vivo antibacterial effect of GTE was confirmed, with an inhibition rate of approximately 90% when compared to that of the E. coli alone group. GTE treatment improved pathogenic E. coli-induced intestinal injury with well-preserved epithelial linings and villi. In addition, the increased expression of annexin A1 in GTE-treated jejunum tissue was detected, which was accompanied by suppressed inflammation-related signal expression, including TNFA, COX-2, and iNOS. Moreover, proliferation-related signals such as PCNA, CD44, and Ki-67 were enhanced in the GTE group compared to those in the E. coli alone group. Taken together, these results indicate that GTE has an antibacterial activity against pathogenic E. coli and ameliorates pathogenic E. coli-induced intestinal damage by modulating inflammation and epithelial cell proliferation.
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14
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Zhao H, Xu Y, Li G, Liu X, Li X, Wang L. Protective efficacy of a novel multivalent vaccine in the prevention of diarrhea induced by enterotoxigenic Escherichia coli in a murine model. J Vet Sci 2021; 23:e7. [PMID: 34841745 PMCID: PMC8799940 DOI: 10.4142/jvs.21068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 08/26/2021] [Accepted: 09/05/2021] [Indexed: 11/23/2022] Open
Abstract
Background Enterotoxigenic Escherichia coli (ETEC) infection is a primary cause of livestock diarrhea. Therefore, effective vaccines are needed to reduce the incidence of ETEC infection. Objectives Our study aimed to develop a multivalent ETEC vaccine targeting major virulence factors of ETEC, including enterotoxins and fimbriae. Methods SLS (STa-LTB-STb) recombinant enterotoxin and fimbriae proteins (F4, F5, F6, F18, and F41) were prepared to develop a multivalent vaccine. A total of 65 mice were immunized subcutaneously by vaccines and phosphate-buffered saline (PBS). The levels of specific immunoglobulin G (IgG) and pro-inflammatory cytokines were determined at 0, 7, 14 and 21 days post-vaccination (dpv). A challenge test with a lethal dose of ETEC was performed, and the survival rate of the mice in each group was recorded. Feces and intestine washes were collected to measure the concentrations of secretory immunoglobulin A (sIgA). Results Anti-SLS and anti-fimbriae-specific IgG in serums of antigen-vaccinated mice were significantly higher than those of the control group. Immunization with the SLS enterotoxin and multivalent vaccine increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations. Compared to diarrheal symptoms and 100% death of mice in the control group, mice inoculated with the multivalent vaccine showed an 80% survival rate without any symptom of diarrhea, while SLS and fimbriae vaccinated groups showed 60 and 70% survival rates, respectively. Conclusions Both SLS and fimbriae proteins can serve as vaccine antigens, and the combination of these two antigens can elicit stronger immune responses. The results suggest that the multivalent vaccine can be successfully used for preventing ETEC in important livestock.
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Affiliation(s)
- Hong Zhao
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Yongping Xu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China.,Dalian SEM Bio-Engineering Technology Co. Ltd., Dalian 116620, China
| | - Gen Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xin Liu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xiaoyu Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Lili Wang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China.
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15
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Hoffmann P, Burmester M, Langeheine M, Brehm R, Empl MT, Seeger B, Breves G. Caco-2/HT29-MTX co-cultured cells as a model for studying physiological properties and toxin-induced effects on intestinal cells. PLoS One 2021; 16:e0257824. [PMID: 34618824 PMCID: PMC8496855 DOI: 10.1371/journal.pone.0257824] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 09/12/2021] [Indexed: 12/28/2022] Open
Abstract
Infectious gastrointestinal diseases are frequently caused by toxins secreted by pathogens which may impair physiological functions of the intestines, for instance by cholera toxin or by heat-labile enterotoxin. To obtain a functional model of the human intestinal epithelium for studying toxin-induced disease mechanisms, differentiated enterocyte-like Caco-2 cells were co-cultured with goblet cell-like HT29-MTX cells. These co-cultures formed a functional epithelial barrier, as characterized by a high electrical resistance and the presence of physiological intestinal properties such as glucose transport and chloride secretion which could be demonstrated electrophysiologically and by measuring protein expression. When the tissues were exposed to cholera toxin or heat-labile enterotoxin in the Ussing chamber, cholera toxin incubation resulted in an increase in short-circuit currents, indicating an increase in apical chloride secretion. This is in line with typical cholera toxin-induced secretory diarrhea in humans, while heat-labile enterotoxin only showed an increase in short-circuit-current in Caco-2 cells. This study characterizes for the first time the simultaneous measurement of physiological properties on a functional and structural level combined with the epithelial responses to bacterial toxins. In conclusion, using this model, physiological responses of the intestine to bacterial toxins can be investigated and characterized. Therefore, this model can serve as an alternative to the use of laboratory animals for characterizing pathophysiological mechanisms of enterotoxins at the intestinal level.
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Affiliation(s)
- Pascal Hoffmann
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marion Burmester
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marion Langeheine
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Ralph Brehm
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Michael T. Empl
- Institute for Food Toxicology, University of Veterinary Medicine, Hannover, Germany
| | - Bettina Seeger
- Institute for Food Toxicology, University of Veterinary Medicine, Hannover, Germany
| | - Gerhard Breves
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
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16
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Sauvaitre T, Durif C, Sivignon A, Chalancon S, Van de Wiele T, Etienne-Mesmin L, Blanquet-Diot S. In Vitro Evaluation of Dietary Fiber Anti-Infectious Properties against Food-Borne Enterotoxigenic Escherichia coli. Nutrients 2021; 13:nu13093188. [PMID: 34579065 PMCID: PMC8471546 DOI: 10.3390/nu13093188] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/27/2021] [Accepted: 09/11/2021] [Indexed: 01/19/2023] Open
Abstract
Dietary fibers have well-known beneficial effects on human health, but their anti-infectious properties against human enteric pathogens have been poorly investigated. Enterotoxigenic Escherichia coli (ETEC) is the main agent of travelers’ diarrhea, against which targeted preventive strategies are currently lacking. ETEC pathogenesis relies on multiple virulence factors allowing interactions with the intestinal mucosal layer and toxins triggering the onset of diarrheal symptoms. Here, we used complementary in vitro assays to study the antagonistic properties of eight fiber-containing products from cereals, legumes or microbes against the prototypical human ETEC strain H10407. Inhibitory effects of these products on the pathogen were tested through growth, toxin production and mucus/cell adhesion inhibition assays. None of the tested compounds inhibited ETEC strain H10407 growth, while lentil extract was able to decrease heat labile toxin (LT) concentration in culture media. Lentil extract and specific yeast cell walls also interfered with ETEC strain H10407 adhesion to mucin beads and human intestinal cells. These results constitute a first step in the use of dietary fibers as a nutritional strategy to prevent ETEC infection. Further work will be dedicated to the study of fiber/ETEC interactions within a complex gut microbial background.
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Affiliation(s)
- Thomas Sauvaitre
- UMR 454 UCA-INRAE Microbiologie Environnement DIgestif et Santé (MEDIS), Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (T.S.); (C.D.); (S.C.); (L.E.-M.)
- Faculty of Bioscience Engineering Center for Microbial Ecology and Technology (CMET), Ghent University, 9000 Ghent, Belgium;
| | - Claude Durif
- UMR 454 UCA-INRAE Microbiologie Environnement DIgestif et Santé (MEDIS), Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (T.S.); (C.D.); (S.C.); (L.E.-M.)
| | - Adeline Sivignon
- UMR 1071 UCA Inserm USC-INRAE 2018 Microbes Intestin Inflammation et Susceptibilité de l’Hôte (M2iSH), Université Clermont Auvergne, 63000 Clermont-Ferrand, France;
| | - Sandrine Chalancon
- UMR 454 UCA-INRAE Microbiologie Environnement DIgestif et Santé (MEDIS), Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (T.S.); (C.D.); (S.C.); (L.E.-M.)
| | - Tom Van de Wiele
- Faculty of Bioscience Engineering Center for Microbial Ecology and Technology (CMET), Ghent University, 9000 Ghent, Belgium;
| | - Lucie Etienne-Mesmin
- UMR 454 UCA-INRAE Microbiologie Environnement DIgestif et Santé (MEDIS), Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (T.S.); (C.D.); (S.C.); (L.E.-M.)
| | - Stéphanie Blanquet-Diot
- UMR 454 UCA-INRAE Microbiologie Environnement DIgestif et Santé (MEDIS), Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (T.S.); (C.D.); (S.C.); (L.E.-M.)
- Correspondence: ; Tel.: +33-473-178-390
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17
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Henrique C, Falcão MAP, De Araújo Pimenta L, Maleski ALA, Lima C, Mitsunari T, Sampaio SC, Lopes-Ferreira M, Piazza RMF. Heat-Labile Toxin from Enterotoxigenic Escherichia coli Causes Systemic Impairment in Zebrafish Model. Toxins (Basel) 2021; 13:419. [PMID: 34204819 PMCID: PMC8231604 DOI: 10.3390/toxins13060419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/05/2021] [Accepted: 05/10/2021] [Indexed: 11/20/2022] Open
Abstract
Heat-labile toxin I (LT-I), produced by strains of enterotoxigenic Escherichia coli (ETEC), causes profuse watery diarrhea in humans. Different in vitro and in vivo models have already elucidated the mechanism of action of this toxin; however, their use does not always allow for more specific studies on how the LT-I toxin acts in systemic tracts and intestinal cell lines. In the present work, zebrafish (Danio rerio) and human intestinal cells (Caco-2) were used as models to study the toxin LT-I. Caco-2 cells were used, in the 62nd passage, at different cell concentrations. LT-I was conjugated to FITC to visualize its transport in cells, as well as microinjected into the caudal vein of zebrafish larvae, in order to investigate its effects on survival, systemic traffic, and morphological formation. The internalization of LT-I was visualized in 3 × 104 Caco-2 cells, being associated with the cell membrane and nucleus. The systemic traffic of LT-I in zebrafish larvae showed its presence in the cardiac cavity, yolk, and regions of the intestine, as demonstrated by cardiac edema (100%), the absence of a swimming bladder (100%), and yolk edema (80%), in addition to growth limitation in the larvae, compared to the control group. There was a reduction in heart rate during the assessment of larval survival kinetics, demonstrating the cardiotoxic effect of LT-I. Thus, in this study, we provide essential new depictions of the features of LT-I.
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Affiliation(s)
- Camila Henrique
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (C.H.); (T.M.)
| | - Maria Alice Pimentel Falcão
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
| | - Luciana De Araújo Pimenta
- Laboratório de Fisiopatologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (L.D.A.P.); (S.C.S.)
| | - Adolfo Luís Almeida Maleski
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
| | - Carla Lima
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
| | - Thais Mitsunari
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (C.H.); (T.M.)
| | - Sandra Coccuzzo Sampaio
- Laboratório de Fisiopatologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (L.D.A.P.); (S.C.S.)
| | - Mônica Lopes-Ferreira
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
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18
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Yu D, Banting G, Neumann NF. A review of the taxonomy, genetics, and biology of the genus Escherichia and the type species Escherichia coli. Can J Microbiol 2021; 67:553-571. [PMID: 33789061 DOI: 10.1139/cjm-2020-0508] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Historically, bacteriologists have relied heavily on biochemical and structural phenotypes for bacterial taxonomic classification. However, advances in comparative genomics have led to greater insights into the remarkable genetic diversity within the microbial world, and even within well-accepted species such as Escherichia coli. The extraordinary genetic diversity in E. coli recapitulates the evolutionary radiation of this species in exploiting a wide range of niches (i.e., ecotypes), including the gastrointestinal system of diverse vertebrate hosts as well as non-host natural environments (soil, natural waters, wastewater), which drives the adaptation, natural selection, and evolution of intragenotypic conspecific specialism as a strategy for survival. Over the last few years, there has been increasing evidence that many E. coli strains are very host (or niche)-specific. While biochemical and phylogenetic evidence support the classification of E. coli as a distinct species, the vast genomic (diverse pan-genome and intragenotypic variability), phenotypic (e.g., metabolic pathways), and ecotypic (host-/niche-specificity) diversity, comparable to the diversity observed in known species complexes, suggest that E. coli is better represented as a complex. Herein we review the taxonomic classification of the genus Escherichia and discuss how phenotype, genotype, and ecotype recapitulate our understanding of the biology of this remarkable bacterium.
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Affiliation(s)
- Daniel Yu
- School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada.,School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada
| | - Graham Banting
- School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada.,School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada
| | - Norman F Neumann
- School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada.,School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada
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19
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Veena H, Gowda SK, Achur RN, Thippeswamy NB. Molecular mechanism of Escherichia coli H10407 induced diarrhoea and its control through immunomodulatory action of bioactives from Simarouba amara (Aubl.). J Microbiol 2021; 59:435-447. [PMID: 33630248 DOI: 10.1007/s12275-021-0423-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/16/2020] [Accepted: 12/31/2020] [Indexed: 10/22/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) infection is a major cause of death in children under the age of five in developing countries. ETEC (O78:H11:CFA/I:LT+:ST+) mechanism has been studied in detail with either heat labile (LT) or heat stable (ST) toxins using in vitro and in vivo models. However, there is no adequate information on ETEC pathogenesis producing both the toxins (LT, ST) in BALB/c mice model. In this study, female mice have been employed to understand ETEC H10407 infection induced changes in physiology, biochemical and immunological patterns up to seven days post-infection and the antidiarrhoeal effect of Simarouba amara (Aubl.) bark aqueous extract (SAAE) has also been looked into. The results indicate that BALB/c is sensitive to ETEC infection resulting in altered jejunum and ileum histomorphology. Withal, ETEC influenced cAMP, PGE2, and NO production resulting in fluid accumulation with varied Na+, K+, Cl-, and Ca2+ levels. Meanwhile, ETEC subverted expression of IL-1β, intestine alkaline phosphatase (IAP), and myeloperoxidase (MPO) in jejunum and ileum. Our data also indicate the severity of pathogenesis reduction which might be due to attainment of equilibrium after reaching optimum rate of infection. Nevertheless, degree of pathogenesis was highly significant (p < 0.01) in all the studied parameters. Besides that, SAAE was successful in reducing the infectious diarrhoea by inhibiting ETEC H10407 in intestine (jejunum and ileum), and shedding in feces. SAAE decreased cAMP, PGE2, and fluid accumulation effectively and boosted the functional activity of immune system in jejunum and ileum IAP, MPO, IL-1β, and nitric oxide.
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Affiliation(s)
- Hegde Veena
- Department of Microbiology, Kuvempu University, Jnana Sahyadri, Shankaraghatta, Shivamogga, 577451, Karnataka, India
| | - Sandesh K Gowda
- Niranthara Scientific Solutions Pvt. Ltd, Bengaluru, 560060, Karnataka, India
| | - Rajeshwara N Achur
- Department of Biochemistry, Kuvempu University, Jnana Sahyadri, Shankaraghatta, Shivamogga, 577451, Karnataka, India
| | - Nayaka Boramuthi Thippeswamy
- Department of Microbiology, Kuvempu University, Jnana Sahyadri, Shankaraghatta, Shivamogga, 577451, Karnataka, India.
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20
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Establishment and Validation of Pathogenic CS17 + and CS19 + Enterotoxigenic Escherichia coli Challenge Models in the New World Primate Aotus nancymaae. Infect Immun 2021; 89:IAI.00479-20. [PMID: 33288648 DOI: 10.1128/iai.00479-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/23/2020] [Indexed: 11/20/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a common cause of diarrheal illness in the military, travelers, and children living in low- to middle-income countries. Increased antibiotic resistance, the absence of a licensed vaccine, and the lack of broadly practical therapeutics perpetuate the significant health and financial burden resulting from ETEC infection. A critical step in the evaluation of vaccines and therapeutics is preclinical screening in a relevant animal disease model that closely replicates human disease. We previously developed a diarrheal model of class 5a colonization factor (CF) CFA/I-expressing ETEC in the New World owl monkey species Aotus nancymaae using ETEC strain H10407. In order to broaden the use of the model, we report here on the development of A. nancymaae models of ETEC expressing the class 5b CFs CS17 and CS19 with strains LSN03-016011/A and WS0115A, respectively. For both models, we observed diarrheal attack rates of ≥80% after oral inoculation with 5 × 1011 CFU of bacteria. These models will aid in assessing the efficacy of future ETEC vaccine candidates and therapeutics.
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21
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Anti-CfaE nanobodies provide broad cross-protection against major pathogenic enterotoxigenic Escherichia coli strains, with implications for vaccine design. Sci Rep 2021; 11:2751. [PMID: 33531570 PMCID: PMC7854682 DOI: 10.1038/s41598-021-81895-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/14/2020] [Indexed: 11/15/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is estimated to cause approximately 380,000 deaths annually during sporadic or epidemic outbreaks worldwide. Development of vaccines against ETEC is very challenging due to the vast heterogeneity of the ETEC strains. An effective vaccines would have to be multicomponent to provide coverage of over ten ETEC strains with genetic variabilities. There is currently no vaccine licensed to prevent ETEC. Nanobodies are successful new biologics in treating mucosal infectious disease as they recognize conserved epitopes on hypervariable pathogens. Cocktails consisting of multiple nanobodies could provide even broader epitope coverage at a lower cost compared to monoclonal antibodies. Identification of conserved epitopes by nanobodies can also assist reverse engineering of an effective vaccine against ETEC. By screening nanobodies from immunized llamas and a naïve yeast display library against adhesins of colonization factors, we identified single nanobodies that show cross-protective potency against eleven major pathogenic ETEC strains in vitro. Oral administration of nanobodies led to a significant reduction of bacterial colonization in animals. Moreover, nanobody-IgA fusion showed extended inhibitory activity in mouse colonization compared to commercial hyperimmune bovine colostrum product used for prevention of ETEC-induced diarrhea. Structural analysis revealed that nanobodies recognized a highly-conserved epitope within the putative receptor binding region of ETEC adhesins. Our findings support further rational design of a pan-ETEC vaccine to elicit robust immune responses targeting this conserved epitope.
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22
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Gong Y, Jin X, Yuan B, Lv Y, Yan G, Liu M, Xie C, Liu J, Tang Y, Gao H, Zhu Y, Huang Y, Wang W. G Protein-Coupled Receptor 109A Maintains the Intestinal Integrity and Protects Against ETEC Mucosal Infection by Promoting IgA Secretion. Front Immunol 2021; 11:583652. [PMID: 33488584 PMCID: PMC7821714 DOI: 10.3389/fimmu.2020.583652] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/03/2020] [Indexed: 12/15/2022] Open
Abstract
Several studies have reported an intricate link between the G protein-coupled receptor 109A (GPR109A) and intestinal health. Upon activation, induced by butyric acid and β-hydroxybutyric acid, GPR109A regulates the expression of tight junction proteins, exerts anti-inflammatory effects, and maintains the integrity of the intestinal barrier. However, its function and the mechanism of action in combating the infection caused by exogenous pathogenic microorganisms remain unclear. This study established an animal model of infection by oral enterotoxigenic Escherichia coli (ETEC) gavage to examine the underlying mechanism(s) and protective effects of GPR109A on the intestinal tract. Experimental GPR109A-/-and GPR109A+/+ mice were orally administered with 1 × 109 colony-forming units (CFUs) of ETEC, and changes in body weight were then observed. The colonization and translocation of ETEC in the intestine were detected by the plate counting method. The expression of tight junction proteins and the levels of inflammatory factors and secretory IgA (SIgA) in the intestine were detected by quantitative real-time polymerase chain reaction (q-PCR), western blotting, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry. The results demonstrated that GPR109A-/-mice were more susceptible to ETEC infection, showing more severe inflammatory reactions and intestinal damage. Moreover, the secretion of IgA in the intestinal tract of GPR109A+/+ mice was significantly increased after ETEC infection, whereas the IgA levels in GPR109A-/-mice did not change significantly. We added 5 g/L sodium butyrate to the drinking water of all mice. The GPR109A+/+ mice were protected against ETEC infection and no effect was observed in GPR109A-/-mice. Similarly, sodium butyrate increased the SIgA content in the gut of the GPR109A+/+ mice and no effect was observed in GPR109A-/-mice. In conclusion, activated GPR109A is effective against the colonization and translocation of ETEC in the gut and maintains the integrity of the intestinal barrier, possibly by promoting the secretion of intestinal IgA.
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Affiliation(s)
- Yuhong Gong
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China.,Laboratory Animal Center of Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xinxin Jin
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China.,Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
| | - Boyu Yuan
- Department of Pharmacology, College of Basic Medical Science, Jilin University, Changchun, China
| | - Yantao Lv
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Guangmou Yan
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Mingming Liu
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China.,Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
| | - Changxin Xie
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Juxiong Liu
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yimei Tang
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Hongyan Gao
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yufeng Zhu
- Laboratory Animal Center of Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yanhua Huang
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Wei Wang
- Innovative Institute of Animal Healthy Breeding, College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China.,Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
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23
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Zhao H, Xu Y, Li G, Liu X, Li X, Wang L. Protective efficacy of a novel multivalent vaccine in the prevention of diarrhea induced by enterotoxigenic Escherichia coli in a murine model. J Vet Sci 2021. [DOI: 10.4142/jvs.2021.22.e90] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Hong Zhao
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Yongping Xu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
- Dalian SEM Bio-Engineering Technology Co. Ltd., Dalian 116620, China
| | - Gen Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xin Liu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xiaoyu Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Lili Wang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
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24
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Foulke-Abel J, Yu H, Sunuwar L, Lin R, Fleckenstein JM, Kaper JB, Donowitz M. Phosphodiesterase 5 (PDE5) restricts intracellular cGMP accumulation during enterotoxigenic Escherichia coli infection. Gut Microbes 2020; 12:1752125. [PMID: 32378997 PMCID: PMC7524150 DOI: 10.1080/19490976.2020.1752125] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/09/2020] [Accepted: 03/27/2020] [Indexed: 02/06/2023] Open
Abstract
Diarrhea caused by enterotoxigenic Escherichia coli (ETEC) has a continuing impact on residents and travelers in underdeveloped countries. Both heat-labile (LT) and heat-stable (ST) enterotoxins contribute to pathophysiology via induction of cyclic nucleotide synthesis, and previous investigations focused on intracellular signal transduction rather than possible intercellular second messenger signaling. We modeled ETEC infection in human jejunal enteroid/organoid monolayers (HEM) and evaluated cyclic nucleotide pools, finding that intracellular cAMP was significantly increased but also underwent apical export, whereas cGMP was minimally retained intracellularly and predominantly effluxed into the basolateral space. LT and virulence factors including EatA, EtpA, and CfaE promoted ST release and enhanced ST-stimulated cGMP production. Intracellular cGMP was regulated by MK-571-sensitive export in addition to degradation by phosphodiesterase 5. HEMs had limited ST-induced intracellular cGMP accumulation compared to T84 or Caco-2 models. Cyclic nucleotide export/degradation demonstrates additional complexity in the mechanism of ETEC infection and may redirect understanding of diarrheal onset.
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Affiliation(s)
- Jennifer Foulke-Abel
- Division of Gastroenterology & Hepatology, Department of Medicine, Johns Hopkins University School of Medicine , Baltimore, MD, USA
| | - Huimin Yu
- Division of Gastroenterology & Hepatology, Department of Medicine, Johns Hopkins University School of Medicine , Baltimore, MD, USA
| | - Laxmi Sunuwar
- Division of Gastroenterology & Hepatology, Department of Medicine, Johns Hopkins University School of Medicine , Baltimore, MD, USA
| | - Ruxian Lin
- Division of Gastroenterology & Hepatology, Department of Medicine, Johns Hopkins University School of Medicine , Baltimore, MD, USA
| | - James M Fleckenstein
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine , St. Louis, MO, USA
| | - James B Kaper
- Department of Microbiology & Immunology, University of Maryland School of Medicine , Baltimore, MD, USA
| | - Mark Donowitz
- Division of Gastroenterology & Hepatology, Department of Medicine, Johns Hopkins University School of Medicine , Baltimore, MD, USA
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25
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CEACAMs serve as toxin-stimulated receptors for enterotoxigenic Escherichia coli. Proc Natl Acad Sci U S A 2020; 117:29055-29062. [PMID: 33139570 DOI: 10.1073/pnas.2012480117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The enterotoxigenic Escherichia coli (ETEC) are among the most common causes of diarrheal illness and death due to diarrhea among young children in low-/middle-income countries (LMICs). ETEC have also been associated with important sequelae including malnutrition and stunting, placing children at further risk of death from diarrhea and other infections. Our understanding of the molecular pathogenesis of acute diarrheal disease as well as the sequelae linked to ETEC are still evolving. It has long been known that ETEC heat-labile toxin (LT) activates production of cAMP in the cell, signaling the modulation of cellular ion channels that results in a net efflux of salt and water into the intestinal lumen, culminating in watery diarrhea. However, as LT also promotes ETEC adhesion to intestinal epithelial cells, we postulated that increases in cAMP, a critical cellular "second messenger," may be linked to changes in cellular architecture that favor pathogen-host interactions. Indeed, here we show that ETEC use LT to up-regulate carcinoembryonic antigenrelated cell adhesion molecules (CEACAMs) on the surface of small intestinal epithelia, where they serve as critical bacterial receptors. Moreover, we show that bacteria are specifically recruited to areas of CEACAM expression, in particular CEACAM6, and that deletion of this CEACAM abrogates both bacterial adhesion and toxin delivery. Collectively, these results provide a paradigm for the molecular pathogenesis of ETEC in which the bacteria use toxin to drive up-regulation of cellular targets that enhances subsequent pathogen-host interactions.
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26
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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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27
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U-Omp19 from Brucella abortus increases dmLT immunogenicity and improves protection against Escherichia coli heat-labile toxin (LT) oral challenge. Vaccine 2020; 38:5027-5035. [PMID: 32536545 PMCID: PMC7327514 DOI: 10.1016/j.vaccine.2020.05.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 01/18/2023]
Abstract
Oral co-administration of dmLT with U-Omp19 increases dmLT immunogenicity. U-Omp19 oral co-delivery with dmLT induces anti-LT antibody responses. U-Omp19 co-administered with dmLT protects against oral challenge with LT. U-Omp19 can allow antigen dose sparing by oral route. U-Omp19 can be used as adjuvant in an oral vaccine formulation against ETEC.
Acute diarrhea disease caused by bacterial infections is a major global health problem. Enterotoxigenic Escherichia coli (ETEC) is one of the top causes of diarrhea-associated morbidity and mortality in young children and travelers to low-income countries. There are currently no licensed vaccines for ETEC. Induction of immunity at the site of entry of the bacteria is key to prevent infection. Current approaches to ETEC vaccines include a less toxic mutant form of E. coli heat-labile toxin (double-mutant heat-labile enterotoxin -dmLT-) with both antigenic and immunostimulatory properties. U-Omp19 is a protease inhibitor from Brucella spp. with immunostimulatory properties that has been used as oral adjuvant. In this work, we use U-Omp19 as adjuvant in an oral vaccine formulation against ETEC containing dmLT in outbred and inbred mice. To evaluate antigen dose sparing by U-Omp19 three different immunization protocols with three different doses of dmLT were evaluated. We demonstrated that U-Omp19 co-delivery increases anti-LT IgA in feces using a mid-dose of dmLT following a prime-boost protocol (after one or two boosts). Oral immunization with U-Omp19 induced protection against LT challenge when co-formulated with dmLT in CD-1 and BALB/c mice. Indeed, there was a significant increase in anti-LT IgG and IgA avidity after a single oral administration of dmLT plus U-Omp19 in comparison with dmLT delivered alone. Interestingly, sera from dmLT plus U-Omp19 vaccinated mice significantly neutralize LT effect on intestine inflammation in vivo compared with sera from the group immunized with dmLT alone. These results demonstrate the adjuvant capacity of U-Omp19 to increase dmLT immunogenicity by the oral route and support its use in an oral subunit vaccine formulation against ETEC.
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28
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Medeiros PHQS, Bolick DT, Ledwaba SE, Kolling GL, Costa DVS, Oriá RB, Lima AÂM, Barry EM, Guerrant RL. A bivalent vaccine confers immunogenicity and protection against Shigella flexneri and enterotoxigenic Escherichia coli infections in mice. NPJ Vaccines 2020; 5:30. [PMID: 32257392 PMCID: PMC7101394 DOI: 10.1038/s41541-020-0180-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 03/06/2020] [Indexed: 12/12/2022] Open
Abstract
Vaccine studies for Shigella flexneri and enterotoxigenic Escherichia coli have been impaired by the lack of optimal animal models. We used two murine models to show that a S. flexneri 2a bivalent vaccine (CVD 1208S-122) expressing enterotoxigenic Escherichia coli colonization factor antigen-I (CFA/I) and the binding subunits A2 and B of heat labile-enterotoxin (LTb) is immunogenic and protects against weight loss and diarrhea. These findings document the immunogenicity and pre-clinical efficacy effects of CVD 1208S-122 vaccine and suggest that further work can help elucidate relevant immune responses and ultimately its clinical efficacy in humans.
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Affiliation(s)
- Pedro Henrique Q S Medeiros
- 1Center for Global Health and Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA USA.,2Institute of Biomedicine, Federal University of Ceará, Fortaleza, CE Brazil
| | - David T Bolick
- 1Center for Global Health and Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA USA
| | - Solanka E Ledwaba
- 1Center for Global Health and Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA USA.,3Department of Microbiology, University of Venda, Thohoyandou, Limpopo province South Africa
| | - Glynis L Kolling
- 1Center for Global Health and Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA USA
| | - Deiziane V S Costa
- 1Center for Global Health and Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA USA.,2Institute of Biomedicine, Federal University of Ceará, Fortaleza, CE Brazil
| | - Reinaldo B Oriá
- 1Center for Global Health and Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA USA.,2Institute of Biomedicine, Federal University of Ceará, Fortaleza, CE Brazil
| | - Aldo Ângelo M Lima
- 2Institute of Biomedicine, Federal University of Ceará, Fortaleza, CE Brazil
| | - Eileen M Barry
- 4Center for Vaccine Development and Global Health, University of Maryland, Baltimore, MD USA
| | - Richard L Guerrant
- 1Center for Global Health and Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA USA
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29
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Seo H, Nandre RM, Nietfeld J, Chen Z, Duan Q, Zhang W. Antibodies induced by enterotoxigenic Escherichia coli (ETEC) adhesin major structural subunit and minor tip adhesin subunit equivalently inhibit bacteria adherence in vitro. PLoS One 2019; 14:e0216076. [PMID: 31042746 PMCID: PMC6493741 DOI: 10.1371/journal.pone.0216076] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/13/2019] [Indexed: 01/15/2023] Open
Abstract
Antibodies that block the adherence of enterotoxigenic Escherichia coli (ETEC) to host intestinal epithelial cells are protective. Multiepitope-fusion-antigens (MEFAs) carrying epitopes of ETEC adhesin major subunits or tip minor subunits induced antibodies against ETEC adherence. Adherence inhibition effectiveness of antibodies induced by major subunit epitopes versus minor tip subunit epitopes, however, has not been comparatively characterized. In this study, we immunized mice with a major subunit MEFA or a tip MEFA, evaluated MEFA anti-adhesin immunogenicity, and examined induced-antibodies against bacteria in vitro adherence or in vivo colonization in mice. Mice subcutaneously immunized with major subunit MEFA CFA/I/II/IV or tip MEFA showed no adverse effects and developed strong antigen-specific antibody responses. Data showed that antibodies derived from two MEFAs were equally effective against adherence of the bacteria expressing CS1, CS2, CS3, CS4/CS6, CS5/CS6, or CS6 adhesin in vitro. Subsequently, we immunized mice with CFA/I fimbriae, major subunit CfaB, or minor tip adhesin subunit CfaE. We found that antibodies induced by CFA/I, CfaB and CfaE equally inhibited in vitro adherence of ETEC strain H10407. Furthermore, we immunized mice with CFA/I fimbriae, CfaB, or CfaE, and then challenged the mice with H10407. Data showed that although not significantly, fewer H10407 bacteria colonized the immunized mice. These results suggest that ETEC adhesin major subunit and minor tip subunit should be equally effective in inducing neutralizing anti-adhesin antibodies, and that major subunit CFA/I/II/IV MEFA or tip MEFA, perhaps combined with toxoid fusion 3xSTaN12S-mnLTR192G/L211A, can be used for development of broadly protective vaccines against ETEC diarrhea.
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Affiliation(s)
- Hyesuk Seo
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, United States of America
| | - Rahul M. Nandre
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America
| | - Jerome Nietfeld
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America
| | - Zhenhai Chen
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America
| | - Qiangde Duan
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America
| | - Weiping Zhang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, United States of America
- * E-mail:
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30
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Establishment, Validation, and Application of a New World Primate Model of Enterotoxigenic Escherichia coli Disease for Vaccine Development. Infect Immun 2019; 87:IAI.00634-18. [PMID: 30510102 DOI: 10.1128/iai.00634-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/19/2018] [Indexed: 12/27/2022] Open
Abstract
The establishment of an animal model that closely approximates enterotoxigenic Escherichia coli (ETEC) disease in humans is critical for the development and evaluation of vaccines against this enteropathogen. Here, we evaluated the susceptibility of Aotus nancymaae, a New World monkey species, to ETEC infection. Animals were challenged orogastrically with 109 to 1011 CFU of the human pathogenic CFA/I+ ETEC strain H10407 and examined for evidence of diarrhea and fecal shedding of bacteria. A clear dose-range effect was obtained, with diarrheal attack rates of 40% to 80%, validated in a follow-on study demonstrating an attack rate of 80% with 1011 CFU of H10407 ETEC. To determine whether this model is an effective approach for assessing ETEC vaccine candidates, we used it to evaluate the ability of the donor strand-complemented CFA/I adhesin CfaE (dscCfaE) to protect against H10407 challenge. In a series of experiments, animals were intranasally vaccinated with dscCfaE alone, dscCfaE with either cholera toxin B-subunit (CTB) or heat-labile toxin (LTB), or phosphate-buffered saline (PBS) alone and then challenged with 1011 CFU of H10407. Control animals vaccinated with PBS had attack rates of 70 to 90% on challenge. Vaccination with dscCfaE, or dscCfaE admixed with CTB or LTB, resulted in a reduction of attack rates, with vaccine efficacies of 66.7% (P = 0.02), 77.7% (P = 0.006), and 42.9% (P = 0.370) to 83.3% (P = 0.041), respectively. In conclusion, we have shown the H10407 ETEC challenge of A. nancymaae to be an effective, reproducible model of ETEC disease, and importantly, we have demonstrated that in this model, vaccination with the prototype vaccine candidate dscCfaE is protective against CF-homologous disease.
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31
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Heat-Stable Enterotoxins of Enterotoxigenic Escherichia coli and Their Impact on Host Immunity. Toxins (Basel) 2019; 11:toxins11010024. [PMID: 30626031 PMCID: PMC6356903 DOI: 10.3390/toxins11010024] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/31/2018] [Accepted: 01/03/2019] [Indexed: 01/12/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are an important diarrhea-causing pathogen and are regarded as a global threat for humans and farm animals. ETEC possess several virulence factors to infect its host, including colonization factors and enterotoxins. Production of heat-stable enterotoxins (STs) by most ETEC plays an essential role in triggering diarrhea and ETEC pathogenesis. In this review, we summarize the heat-stable enterotoxins of ETEC strains from different species as well as the molecular mechanisms used by these heat-stable enterotoxins to trigger diarrhea. As recently described, intestinal epithelial cells are important modulators of the intestinal immune system. Thus, we also discuss the impact of the heat-stable enterotoxins on this role of the intestinal epithelium and how these enterotoxins might affect intestinal immune cells. Finally, the latest developments in vaccination strategies to protect against infections with ST secreting ETEC strains are discussed. This review might inform and guide future research on heat-stable enterotoxins to further unravel their molecular pathogenesis, as well as to accelerate vaccine design.
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32
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Subramenium GA, Sabui S, Marchant JS, Said HM, Subramanian VS. Enterotoxigenic Escherichia coli heat labile enterotoxin inhibits intestinal ascorbic acid uptake via a cAMP-dependent NF-κB-mediated pathway. Am J Physiol Gastrointest Liver Physiol 2019; 316:G55-G63. [PMID: 30285481 PMCID: PMC6383388 DOI: 10.1152/ajpgi.00259.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Vitamin C is an antioxidant and acts as a cofactor for many enzymatic reactions. Humans obtain vitamin C from dietary sources via intestinal absorption, a process that involves the sodium-dependent vitamin C transporters-1 and -2 (SVCT1 and SVCT2). Enterotoxigenic Escherichia coli (ETEC) infection impacts intestinal absorption/secretory functions, but nothing is known about its effect on ascorbic acid (AA) uptake. Here we demonstrate that infection of Caco-2 cells with ETEC led to a significant inhibition in intestinal AA uptake. This inhibition was associated with a marked reduction in hSVCT1 and hSVCT2 protein, mRNA, and heterogeneous nuclear RNA (hnRNA) expression levels as well as significant inhibition in the activity of both the SLC23A1 and SLC23A2 promoters. Similarly, exposure of mice to ETEC led to a significant inhibition in intestinal AA uptake and reduction in mSVCT1 and mSVCT2 protein, mRNA, and hnRNA expression levels. Inhibition was caused by the action of heat labile enterotoxin (LT), since infecting Caco-2 cells with LT-deficient ETEC (ΔLT) failed to impact AA uptake. Because LT activates adenylate cyclase, we also examined the effect of dibutyryl-cAMP in AA uptake by Caco-2 cells and observed a significant inhibition. Furthermore, treating the cells with celastrol, a specific NF-κB inhibitor, significantly blocked the inhibition of AA uptake caused by ETEC infection. Together, these data demonstrate that ETEC infection impairs intestinal AA uptake through a cAMP-dependent NF-κB-mediated pathway that regulates both SLC23A1 and SLC23A2 transcription. NEW & NOTEWORTHY Our findings demonstrate that heat-labile enterotoxin produced by enterotoxigenic Escherichia coli inhibits AA uptake in intestinal epithelial cells and mouse intestine. This effect is mediated through transcriptional repression of SLC23A1 (SVCT1) and SLC23A2 (SVCT2) via a cAMP-dependent NF-κB signaling pathway.
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Affiliation(s)
- Ganapathy A. Subramenium
- 1Department of Medicine, University of California, Irvine, California,3Department of Veterans Affairs Medical Center, Long Beach, California
| | - Subrata Sabui
- 1Department of Medicine, University of California, Irvine, California,2Department of Physiology and Biophysics, University of California, Irvine, California,3Department of Veterans Affairs Medical Center, Long Beach, California
| | - Jonathan S. Marchant
- 4Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Hamid M. Said
- 1Department of Medicine, University of California, Irvine, California,2Department of Physiology and Biophysics, University of California, Irvine, California,3Department of Veterans Affairs Medical Center, Long Beach, California
| | - Veedamali S. Subramanian
- 1Department of Medicine, University of California, Irvine, California,2Department of Physiology and Biophysics, University of California, Irvine, California,3Department of Veterans Affairs Medical Center, Long Beach, California
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Stromberg ZR, Van Goor A, Redweik GAJ, Wymore Brand MJ, Wannemuehler MJ, Mellata M. Pathogenic and non-pathogenic Escherichia coli colonization and host inflammatory response in a defined microbiota mouse model. Dis Model Mech 2018; 11:dmm035063. [PMID: 30275104 PMCID: PMC6262807 DOI: 10.1242/dmm.035063] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/24/2018] [Indexed: 12/17/2022] Open
Abstract
Most Escherichia coli strains in the human intestine are harmless. However, enterohemorrhagic Ecoli (EHEC) is a foodborne pathogen that causes intestinal disease in humans. Conventionally reared (CONV) mice are inconsistent models for human infections with EHEC because they are often resistant to Ecoli colonization, in part due to their gastrointestinal (GI) microbiota. Although antibiotic manipulation of the mouse microbiota has been a common means to overcome colonization resistance, these models have limitations. Currently, there are no licensed treatments for clinical EHEC infections and, thus, new tools to study EHEC colonization need to be developed. Here, we used a defined microbiota mouse model, consisting of the altered Schaedler flora (ASF), to characterize intestinal colonization and compare host responses following colonization with EHEC strain 278F2 or non-pathogenic Ecoli strain MG1655. Significantly higher (P<0.05) levels of both strains were found in feces and cecal and colonic contents of C3H/HeN ASF compared to C3H/HeN CONV mice. GI inflammation was significantly elevated (P<0.05) in the cecum of EHEC 278F2-colonized compared to E. coli MG1655-colonized C3H/HeN ASF mice. In addition, EHEC 278F2 differentially modulated inflammatory-associated genes in colonic tissue of C3H/HeN ASF mice compared to E. coli MG1655-colonized mice. This approach allowed for prolonged colonization of the murine GI tract by pathogenic and non-pathogenic Ecoli strains, and for evaluation of host inflammatory processes. Overall, this system can be used as a powerful tool for future studies to assess therapeutics, microbe-microbe interactions, and strategies for preventing EHEC infections.
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Affiliation(s)
- Zachary R Stromberg
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA
| | - Angelica Van Goor
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA
| | - Graham A J Redweik
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA
| | - Meghan J Wymore Brand
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA 50011, USA
| | - Michael J Wannemuehler
- Department of Veterinary Microbiology and Preventive Medicine, 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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Petrova IO, Konopsky VN, Sukhanova AV, Nabiev IR. Multiparametric detection of bacterial contamination based on the photonic crystal surface mode detection. BULLETIN OF RUSSIAN STATE MEDICAL UNIVERSITY 2018. [DOI: 10.24075/brsmu.2018.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Conventional techniques for food and water quality control and environmental monitoring in general have a number of drawbacks. Below we propose a label-free highly accurate analytical technique for multiplex detection of biomarkers based on the analysis of propagation of Bloch waves on the surface of a photonic crystal. The technique can be used to measure molecular and cell affinity interactions in real time by recording critical and excitation angles of the surface wave on the surface of a photonic crystal. Based on the analysis of photonic crystal surface modes, we elaborated a protocol for the detection of the exotoxin A of Pseudomonas aeruginosa and the heat-labile toxin LT of Escherichia coli. The protocol exploits detection of affinity interactions between antigens pumped through a microfluidic cell and detector antibodies conjugated to the chemically activated silica chip. The proposed technique is highly sensitive, cheap and less time-consuming in comparison with surface plasmon resonance.
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Affiliation(s)
- I. O. Petrova
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow
| | - V. N. Konopsky
- Laboratory of Spectroscopy of Condensed Matter, Institute for Spectroscopy, Russian Academy of Sciences, Troitsk
| | - A. V. Sukhanova
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow
| | - I. R. Nabiev
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow
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Identification and Characterization of Human Monoclonal Antibodies for Immunoprophylaxis against Enterotoxigenic Escherichia coli Infection. Infect Immun 2018; 86:IAI.00355-18. [PMID: 29866909 PMCID: PMC6056861 DOI: 10.1128/iai.00355-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 05/31/2018] [Indexed: 11/20/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) causes diarrheal illness in infants in the developing world and travelers to countries where the disease is endemic, including military personnel. ETEC infection of the host involves colonization of the small intestinal epithelium and toxin secretion, leading to watery diarrhea. Enterotoxigenic Escherichia coli (ETEC) causes diarrheal illness in infants in the developing world and travelers to countries where the disease is endemic, including military personnel. ETEC infection of the host involves colonization of the small intestinal epithelium and toxin secretion, leading to watery diarrhea. There is currently no vaccine licensed to prevent ETEC infection. CFA/I is one of the most common colonization factor antigens (CFAs). The CFA/I adhesin subunit, CfaE, is required for ETEC adhesion to host intestinal cells. Human antibodies against CfaE have the potential to block colonization of ETEC and serve as an immunoprophylactic against ETEC-related diarrhea. Mice transgenic for human immunoglobulin genes were immunized with CfaE to generate a panel of human monoclonal IgG1 antibodies (HuMAbs). The most potent IgG1 antibodies identified in the in vitro functional assays were selected and isotype switched to secretory IgA (sIgA) and tested in animal colonization assays via oral administration. Over 300 unique anti-CfaE IgG1 HuMAbs were identified. The lead IgG1 anti-CfaE HuMAbs completely inhibited hemagglutination and blocked adhesion of ETEC to Caco-2 cells. Epitope mapping studies revealed that HuMAbs recognized epitopes in the N-terminal domain of CfaE near the putative receptor binding site. Oral administration of anti-CfaE antibodies in either IgG or sIgA isotypes inhibited intestinal colonization in mice challenged with ETEC. A 2- to 4-log decrease in CFU was observed in comparison to mice challenged with irrelevant isotype controls. We identified fully human monoclonal antibodies against the CfaE adhesion domain that can be potentially employed as an immunoprophylactic to prevent ETEC-related diarrhea.
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36
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Critical Role of Zinc in a New Murine Model of Enterotoxigenic Escherichia coli Diarrhea. Infect Immun 2018; 86:IAI.00183-18. [PMID: 29661930 PMCID: PMC6013668 DOI: 10.1128/iai.00183-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/11/2018] [Indexed: 12/11/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of traveler's diarrhea as well as of endemic diarrhea and stunting in children in developing areas. However, a small-mammal model has been badly needed to better understand and assess mechanisms, vaccines, and interventions. We report a murine model of ETEC diarrhea, weight loss, and enteropathy and investigate the role of zinc in the outcomes. ETEC strains producing heat-labile toxins (LT) and heat-stable toxins (ST) that were given to weaned C57BL/6 mice after antibiotic disruption of normal microbiota caused growth impairment, watery diarrhea, heavy stool shedding, and mild to moderate intestinal inflammation, the latter being worse with zinc deficiency. Zinc treatment promoted growth in zinc-deficient infected mice, and subinhibitory levels of zinc reduced expression of ETEC virulence genes cfa1, cexE, sta2, and degP but not of eltA in vitro Zinc supplementation increased shedding and the ileal burden of wild-type (WT) ETEC but decreased shedding and the tissue burden of LT knockout (LTKO) ETEC. LTKO ETEC-infected mice had delayed disease onset and also had less inflammation by fecal myeloperoxidase (MPO) assessment. These findings provide a new murine model of ETEC infection that can help elucidate mechanisms of growth, diarrhea, and inflammatory responses as well as potential vaccines and interventions.
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Anti-infectious properties of the probiotic Saccharomyces cerevisiae CNCM I-3856 on enterotoxigenic E. coli (ETEC) strain H10407. Appl Microbiol Biotechnol 2018; 102:6175-6189. [DOI: 10.1007/s00253-018-9053-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 12/15/2022]
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Zhang D, Yang L, Su W, Zhao Y, Ma X, Zhou H, Xu B, Zhang K, Ma H. Aquaporin-4 Is Downregulated in the Basolateral Membrane of Ileum Epithelial Cells during Enterotoxigenic Escherichia coli-Induced Diarrhea in Mice. Front Microbiol 2018; 8:2655. [PMID: 29375520 PMCID: PMC5767235 DOI: 10.3389/fmicb.2017.02655] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 12/20/2017] [Indexed: 01/28/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are opportunistic pathogens that colonize the small intestine, produce enterotoxins and induce diarrhea. Some aquaporins (AQPs), such as AQP3 and AQP8, have been reported to participate in diarrhea by decreasing cellular influx in the gastrointestinal (GI) tract. AQP4 is another important water channel in the GI tract, but its role in ETEC-induced diarrhea has not been reported. Here, we demonstrated the potential roles of AQP4 in ETEC-induced diarrhea. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting showed that AQP4 was expressed in the mouse ileum, but not in the duodenum or jejunum while immunohistochemical staining showed that AQP4 localized to the basolateral membrane of ileum epithelial cells. Using an ETEC-induced mice diarrhea model, we demonstrated that both AQP4 mRNA level and the AQP4 protein level in the ileum decreased gradually over a time course of 7 days. These results suggest that AQP4 plays a role in the pathogenesis of ETEC-induced diarrhea by mediating water transport.
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Affiliation(s)
- Di Zhang
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Longfei Yang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
| | - Weiheng Su
- National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun, China
| | - Yuan Zhao
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China.,The Key Laboratory of Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, China
| | - Xin Ma
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Haizhu Zhou
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Bo Xu
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Kaiqi Zhang
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Hongxia Ma
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China.,The Key Laboratory of Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, China
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Wu X, Su D. Enterotoxigenic Escherichia coli infection induces tight junction proteins expression in mice. IRANIAN JOURNAL OF VETERINARY RESEARCH 2018; 19:35-40. [PMID: 29805460 PMCID: PMC5960770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/26/2017] [Accepted: 10/07/2017] [Indexed: 06/08/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in travelers, young children and piglets, but the precise pathogenesis of ETEC induced diarrhea is not fully known. Recent investigations have shown that tight junction (TJ) proteins and aquaporin 3 (AQP 3) are contributing factors in bacterial diarrhea. In this study, using immunoblotting and immunohistochemistry analyses, we found that ETEC increases the protein abundance of TJ proteins (occludin, claudin-1, zonula occludens-1) in mice. Enterotoxigenic Escherichia coli induced the expression of TJ proteins in mice through pathways by involving myosin light chain kinase (MLCK)-myosin II regulatory light chain (MLC20) pathways; however, ETEC has little effect on the activation of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway. Enterotoxigenic Escherichia coli infection has little effect on the protein abundance of AQP 3. Collectively, ETEC infection affects the abundance of intestinal TJ protein, which suggests the importance of TJ proteins in ETEC induced diarrhea.
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Affiliation(s)
- X. Wu
- Correspondence: X. Wu, College of Animal Science and Technology, Hunan Agricultural University, Changsha, Hunan 410128, China. E-mail:
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40
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Wenzel H, Kaminski RW, Clarkson KA, Maciel M, Smith MA, Zhang W, Oaks EV. Improving chances for successful clinical outcomes with better preclinical models. Vaccine 2017; 35:6798-6802. [DOI: 10.1016/j.vaccine.2017.08.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 08/10/2017] [Indexed: 11/30/2022]
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41
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Petitjean M, Martak D, Silvant A, Bertrand X, Valot B, Hocquet D. Genomic characterization of a local epidemic Pseudomonas aeruginosa reveals specific features of the widespread clone ST395. Microb Genom 2017; 3:e000129. [PMID: 29177088 PMCID: PMC5695207 DOI: 10.1099/mgen.0.000129] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/23/2017] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen with several clones being frequently associated with outbreaks in hospital settings. ST395 is among these so-called ‘international’ clones. We aimed here to define the biological features that could have helped the implantation and spread of the clone ST395 in hospital settings. The complete genome of a multidrug resistant index isolate (DHS01) of a large hospital outbreak was analysed. We identified DHS01-specific genetic elements, among which were identified those shared with a panel of six independent ST395 isolates responsible for outbreaks in other hospitals. DHS01 has the fifth largest chromosome of the species (7.1 Mbp), with most of its 1555 accessory genes borne by either genomic islands (GIs, n=48) or integrative and conjugative elements (ICEs, n=5). DHS01 is multidrug resistant mostly due to chromosomal mutations. It displayed signatures of adaptation to chronic infection in part due to the loss of a 131 kbp chromosomal fragment. Four GIs were specific to the clone ST395 and contained genes involved in metabolism (GI-4), in virulence (GI-6) and in resistance to copper (GI-7). GI-7 harboured an array of six copper transporters and was shared with non-pathogenic Pseudomonas sp. retrieved from copper-contaminated environments. Copper resistance was confirmed phenotypically in all other ST395 isolates and possibly accounted for the spreading capability of the clone in hospital outbreaks, where water networks have been incriminated. This suggests that genes transferred from copper-polluted environments may have favoured the implantation and spread of the international clone P. aeruginosa ST395 in hospital settings.
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Affiliation(s)
- Marie Petitjean
- 1Hygiène Hospitalière, Centre Hospitalier Régional Universitaire de Besançon, Besançon, France.,2UMR CNRS 6249 Chrono-Environnement, Université de Bourgogne Franche-Comté, Besançon, France
| | - Daniel Martak
- 1Hygiène Hospitalière, Centre Hospitalier Régional Universitaire de Besançon, Besançon, France.,2UMR CNRS 6249 Chrono-Environnement, Université de Bourgogne Franche-Comté, Besançon, France
| | - Alicia Silvant
- 1Hygiène Hospitalière, Centre Hospitalier Régional Universitaire de Besançon, Besançon, France
| | - Xavier Bertrand
- 1Hygiène Hospitalière, Centre Hospitalier Régional Universitaire de Besançon, Besançon, France.,2UMR CNRS 6249 Chrono-Environnement, Université de Bourgogne Franche-Comté, Besançon, France
| | - Benoit Valot
- 2UMR CNRS 6249 Chrono-Environnement, Université de Bourgogne Franche-Comté, Besançon, France
| | - Didier Hocquet
- 2UMR CNRS 6249 Chrono-Environnement, Université de Bourgogne Franche-Comté, Besançon, France.,3Centre de Ressources Biologiques - Filière Microbiologique, Centre Hospitalier Universitaire de Besançon, 3 Boulevard Fleming, Besançon, France.,1Hygiène Hospitalière, Centre Hospitalier Régional Universitaire de Besançon, Besançon, France
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Lu X, Li C, Li C, Li P, Fu E, Xie Y, Jin F. Heat-Labile Enterotoxin-Induced PERK-CHOP Pathway Activation Causes Intestinal Epithelial Cell Apoptosis. Front Cell Infect Microbiol 2017. [PMID: 28642847 PMCID: PMC5463185 DOI: 10.3389/fcimb.2017.00244] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea among children and travelers in developing countries, and heat-labile enterotoxin (LT) is one of the most important virulence factors. The pathogenesis of and virulence factors associated with ETEC have been well-characterized; however, the extent to which ETEC damages host cells remains unclear. In this study, we found that LT could induce decreases in intestinal epithelial cell viability and induce apoptosis in a dose- and time- dependent manner in both HCT-8 and Caco-2 cells. We analyzed the expression profiles of apoptosis-related proteins via protein array technology and found that Bax, p-p53(S46), cleaved caspase-3, and TNFRI/TNFRSF1A expression levels were significantly up-regulated in wild-type ETEC- but not in ΔLT ETEC-infected HCT-8 cells. Bax is essential for endoplasmic reticulum (ER) stress-triggered apoptosis, and our RNAi experiments showed that the PERK-eIF2-CHOP pathway and reactive oxygen species (ROS) are also main participants in this process. LT-induced ROS generation was decreased in CHOP-knockdown HCT-8 cells compared to that in control cells. Moreover, pretreatment with the ROS inhibitor NAC down-regulated GRP78, CHOP, Bim, and cleaved caspase-3 expression, resulting in a reduction in the apoptosis rate from 36.2 to 20.3% in LT-treated HCT-8 cells. Furthermore, ROS inhibition also attenuated LT-induced apoptosis in the small intestinal mucosa in the ETEC-inoculation mouse model.
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Affiliation(s)
- Xi Lu
- Department of Respiration, Tangdu Hospital, Fourth Military Medical UniversityXi'an, China
| | - Chunmeng Li
- Bacteriology Room in Department of Clinical Laboratory, Shaanxi Province Hospital of Traditional Chinese MedicineXi'an, China
| | - Congcong Li
- Department of Respiration, Tangdu Hospital, Fourth Military Medical UniversityXi'an, China
| | - Pengcheng Li
- Department of Respiration, Tangdu Hospital, Fourth Military Medical UniversityXi'an, China
| | - Enqing Fu
- Department of Respiration, Tangdu Hospital, Fourth Military Medical UniversityXi'an, China
| | - Yonghong Xie
- Department of Respiration, Tangdu Hospital, Fourth Military Medical UniversityXi'an, China
| | - Faguang Jin
- Department of Respiration, Tangdu Hospital, Fourth Military Medical UniversityXi'an, China
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Rodea GE, Montiel-Infante FX, Cruz-Córdova A, Saldaña-Ahuactzi Z, Ochoa SA, Espinosa-Mazariego K, Hernández-Castro R, Xicohtencatl-Cortes J. Tracking Bioluminescent ETEC during In vivo BALB/c Mouse Colonization. Front Cell Infect Microbiol 2017; 7:187. [PMID: 28560186 PMCID: PMC5432549 DOI: 10.3389/fcimb.2017.00187] [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: 03/03/2017] [Accepted: 04/28/2017] [Indexed: 12/14/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea worldwide. Adhesion to the human intestinal tract is crucial for colonization. ETEC adhesive structures have been extensively studied; however, colonization dynamics remain uncharacterized. The aim of this study was to track bioluminescent ETEC during in vivo infection. The promoter region of dnaK was fused with the luc gene, resulting in the pRMkluc vector. E. coli K-12 and ETEC FMU073332 strains were electroporated with pRMkluc. E. coli K-12 pRMkluc was bioluminescent; in contrast, the E. coli K-12 control strain did not emit bioluminescence. The highest light emission was measured at 1.9 OD600 (9 h) and quantified over time. The signal was detected starting at time 0 and up to 12 h. Streptomycin-treated BALB/c mice were orogastrically inoculated with either ETEC FMU073332 pRMkluc or E. coli K-12 pRMkluc (control), and bacterial colonization was determined by measuring bacterial shedding in the feces. ETEC FMU073332 pRMkluc shedding started and stopped after inoculation of the control strain, indicating that mouse intestinal colonization by ETEC FMU073332 pRMkluc lasted longer than colonization by the control. The bioluminescence signal of ETEC FMU073332 pRMkluc was captured starting at the time of inoculation until 12 h after inoculation. The bioluminescent signal emitted by ETEC FMU073332 pRMkluc in the proximal mouse ileum was located, and the control signal was identified in the cecum. The detection of maximal light emission and bioluminescence duration allowed us to follow ETEC during in vivo infection. ETEC showed an enhanced colonization and tropism in the mouse intestine compared with those in the control strain. Here, we report the first study of ETEC colonization in the mouse intestine accompanied by in vivo imaging.
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Affiliation(s)
- Gerardo E Rodea
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico GómezCiudad de México, Mexico.,Instituto de Fisiología Celular, Universidad Nacional Autónoma de MéxicoCiudad de México, Mexico
| | - Francisco X Montiel-Infante
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico GómezCiudad de México, Mexico
| | - Ariadnna Cruz-Córdova
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico GómezCiudad de México, Mexico
| | - Zeus Saldaña-Ahuactzi
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico GómezCiudad de México, Mexico
| | - Sara A Ochoa
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico GómezCiudad de México, Mexico
| | - Karina Espinosa-Mazariego
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico GómezCiudad de México, Mexico
| | - Rigoberto Hernández-Castro
- Departamento de Ecología de Agentes Patógenos, Hospital General "Dr. Manuel Gea González"Ciudad de México, Mexico
| | - Juan Xicohtencatl-Cortes
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico GómezCiudad de México, Mexico
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Vogt SL, Finlay BB. Gut microbiota-mediated protection against diarrheal infections. J Travel Med 2017; 24:S39-S43. [PMID: 28520994 PMCID: PMC5731444 DOI: 10.1093/jtm/taw086] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 11/10/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND The mammalian gut microbiota is a highly abundant and diverse microbial community that resides in the gastrointestinal tract. One major benefit that the gut microbiota provides to its host is colonization resistance-the ability to prevent colonization by foreign microbes, including diarrheal pathogens such as Clostridium difficile , Salmonella enterica serovar Typhimurium and diarrheagenic Escherichia coli . METHODS We conducted a literature review of the effects of the gut microbiota on infection by diarrheal pathogens. We used PubMed to search for relevant articles published before July 2016, as well as incorporated data from our laboratory. RESULTS The gut microbiota provides protection from diarrheal infections both by direct inhibition of pathogens and by indirect effects on host functions. Direct effects of the microbiota on diarrheal pathogens include competing for nutrients and producing metabolites that inhibit pathogen growth or virulence. Indirect effects of the gut microbiota include promoting maintenance of the gut mucosal barrier and stimulating innate and adaptive immunity. CONCLUSIONS Human epidemiological studies and experimental infections of laboratory animals both demonstrate that antibiotic treatment can alter the gut microbial community and thereby reduce colonization resistance against diarrheal pathogens. Further research might lead to the development of next-generation probiotics that could be used to bolster colonization resistance and thus prevent travellers' diarrheal.
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Affiliation(s)
- Stefanie L Vogt
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - B Brett Finlay
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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45
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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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Dynamic Interactions of a Conserved Enterotoxigenic Escherichia coli Adhesin with Intestinal Mucins Govern Epithelium Engagement and Toxin Delivery. Infect Immun 2016; 84:3608-3617. [PMID: 27736776 PMCID: PMC5116737 DOI: 10.1128/iai.00692-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/02/2016] [Indexed: 12/30/2022] Open
Abstract
At present, there is no vaccine for enterotoxigenic Escherichia coli (ETEC), an important cause of diarrheal illness. Nevertheless, recent microbial pathogenesis studies have identified a number of molecules produced by ETEC that contribute to its virulence and are novel antigenic targets to complement canonical vaccine approaches. EtpA is a secreted two-partner adhesin that is conserved within the ETEC pathovar. EtpA interacts with the tips of ETEC flagella to promote bacterial adhesion, toxin delivery, and intestinal colonization by forming molecular bridges between the bacteria and the epithelial surface. However, the nature of EtpA interactions with the intestinal epithelium remains poorly defined. Here, we demonstrate that EtpA interacts with glycans presented by transmembrane and secreted intestinal mucins at epithelial surfaces to facilitate pathogen-host interactions that culminate in toxin delivery. Moreover, we found that a major effector molecule of ETEC, the heat-labile enterotoxin (LT), may enhance these interactions by stimulating the production of the gel-forming mucin MUC2. Our studies suggest, however, that EtpA participates in complex and dynamic interactions between ETEC and the gastrointestinal mucosae in which host glycoproteins promote bacterial attachment while simultaneously limiting the epithelial engagement required for effective toxin delivery. Collectively, these data provide additional insight into the intricate nature of ETEC interactions with the intestinal epithelium that have potential implications for rational approaches to vaccine design.
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47
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Immunogenicity and Protective Efficacy against Enterotoxigenic Escherichia coli Colonization following Intradermal, Sublingual, or Oral Vaccination with EtpA Adhesin. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2016; 23:628-37. [PMID: 27226279 DOI: 10.1128/cvi.00248-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 05/17/2016] [Indexed: 12/16/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are a common cause of diarrhea. Extraordinary antigenic diversity has prompted a search for conserved antigens to complement canonical approaches to ETEC vaccine development. EtpA, an immunogenic extracellular ETEC adhesin relatively conserved in the ETEC pathovar, has previously been shown to be a protective antigen following intranasal immunization. These studies were undertaken to explore alternative routes of EtpA vaccination that would permit use of a double mutant (R192G L211A) heat-labile toxin (dmLT) adjuvant. Here, oral vaccination with EtpA adjuvanted with dmLT afforded significant protection against small intestinal colonization, and the degree of protection correlated with fecal IgG, IgA, or total fecal antibody responses to EtpA. Sublingual vaccination yielded compartmentalized mucosal immune responses with significant increases in anti-EtpA fecal IgG and IgA, and mice vaccinated via this route were also protected against colonization. In contrast, while intradermal (i.d.) vaccination achieved high levels of both serum and fecal antibodies against both EtpA and dmLT, mice vaccinated via the i.d. route were not protected against subsequent colonization and the avidity of serum IgG and IgA EtpA-specific antibodies was significantly lower after i.d. immunization compared to other routes. Finally, we demonstrate that antiserum from vaccinated mice significantly impairs binding of LT to cognate GM1 receptors and shows near complete neutralization of toxin delivery by ETEC in vitro Collectively, these data provide further evidence that EtpA could complement future vaccine strategies but also suggest that additional effort will be required to optimize its use as a protective immunogen.
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YANG XIANGWU, XIAO ZHIMING, LIU FEN, CHEN SHUAI, TANG WULIANG, ZHANG DECAI, LIU SHAOJUN. Enterotoxigenic Escherichia coli infection alters intestinal immunity in mice. Mol Med Rep 2016; 14:825-30. [DOI: 10.3892/mmr.2016.5302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 04/07/2016] [Indexed: 11/06/2022] Open
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Yang Y, Yang Y, Ou B, Xia P, Zhou M, Li L, Zhu G. The flagellin hypervariable region is a potential flagella display domain in probiotic Escherichia coli strain Nissle 1917. Arch Microbiol 2016; 198:603-10. [PMID: 27071621 DOI: 10.1007/s00203-016-1219-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 03/29/2016] [Accepted: 04/05/2016] [Indexed: 12/11/2022]
Abstract
The most studied probiotic, Escherichia coli strain Nissle 1917 (EcN) possesses flagella of serotype H1. To explore the potential to use EcN flagellin in flagella display applications, we investigated the effect of deleting amino acids in the hypervariable region of flagellin on EcNc (EcN cured of its two cryptic plasmids pMUT1 and pMUT2). Two EcNc flagellin isogenic mutants with deletions of amino acid residual from 277 to 286 and from 287 to 296 in the hypervariable domain were constructed. Both mutants were flagellated, adherent to IPEC-J2 cells, and colonized BALB/c mice. These hypervariable regions may have future utility in the display of heterologous epitopes.
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Affiliation(s)
- Ying Yang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, People's Republic of China
| | - Yi Yang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, People's Republic of China
| | - Bingming Ou
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, People's Republic of China
| | - Pengpeng Xia
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, People's Republic of China
| | - Mingxu Zhou
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, People's Republic of China
| | - Luan Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, People's Republic of China.,Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
| | - Guoqiang Zhu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, People's Republic of China. .,Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, People's Republic of China.
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50
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Zhang C, Iqbal J, Gómez-Duarte OG. Murine immunization with CS21 pili or LngA major subunit of enterotoxigenic Escherichia coli (ETEC) elicits systemic and mucosal immune responses and inhibits ETEC gut colonization. Vet Microbiol 2016; 202:90-100. [PMID: 26878971 DOI: 10.1016/j.vetmic.2016.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/24/2016] [Accepted: 02/04/2016] [Indexed: 02/07/2023]
Abstract
CS21 pili of enterotoxigenic Escherichia coli (ETEC) is one of the most prevalent ETEC colonization factors. CS21 major subunit, LngA, mediates ETEC adherence to intestinal cells, and contributes to ETEC pathogenesis in a neonatal mouse infection model. The objectives of this work were to evaluate LngA major subunit purified protein and CS21 purified pili on immunogenicity and protection against ETEC colonization of mice intestine. Recombinant LngA purified protein or purified CS21 pili from E9034A ETEC strain were evaluated for immunogenicity after immunization of C57BL/6 mice. Specific anti-LngA antibodies were detected from mice serum, feces, and intestine fluid samples by ELISA assays. Protection against gut colonization was evaluated on immunized mice orally challenged with wild type E9034A ETEC strain and by subsequent quantification of bacterial colony forming units (CFU) recovered from feces. Recombinant LngA protein and CS21 pili induced specific humoral and mucosal anti-LngA antibodies in the mouse model. CS21 combined with CT delivered intranasally as well as LngA combined with incomplete Freund adjuvant delivered intraperitoneally inhibited ETEC gut colonization in a mouse model. In conclusion, both LngA purified protein and CS21 pili from ETEC are highly immunogenic and may inhibit ETEC intestinal shedding. Our data on immunogenicity and immunoprotection indicates that CS21 is a suitable vaccine candidate for a future multivalent vaccine against ETEC diarrhea.
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Affiliation(s)
- Chengxian Zhang
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Junaid Iqbal
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Oscar G Gómez-Duarte
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA.
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