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Liu Z, Zhang H, Lemaitre B, Li X. Duox activation in Drosophila Malpighian tubules stimulates intestinal epithelial renewal through a countercurrent flow. Cell Rep 2024; 43:114109. [PMID: 38613782 DOI: 10.1016/j.celrep.2024.114109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 02/26/2024] [Accepted: 03/28/2024] [Indexed: 04/15/2024] Open
Abstract
The gut must perform a dual role of protecting the host against toxins and pathogens while harboring mutualistic microbiota. Previous studies suggested that the NADPH oxidase Duox contributes to intestinal homeostasis in Drosophila by producing reactive oxygen species (ROS) in the gut that stimulate epithelial renewal. We find instead that the ROS generated by Duox in the Malpighian tubules leads to the production of Upd3, which enters the gut and stimulates stem cell proliferation. We describe in Drosophila the existence of a countercurrent flow system, which pushes tubule-derived Upd3 to the anterior part of the gut and stimulates epithelial renewal at a distance. Thus, our paper clarifies the role of Duox in gut homeostasis and describes the existence of retrograde fluid flow in the gut, collectively revealing a fascinating example of inter-organ communication.
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Affiliation(s)
- Zhonggeng Liu
- Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Hongyu Zhang
- Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Bruno Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Xiaoxue Li
- Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China; Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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2
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Fischer Sigel LK, Sánchez DS, Sacerdoti F, Zotta E, Silberstein C. Progression of renal damage and tubular regeneration in pregnant and non-pregnant adult female rats inoculated with a sublethal dose of Shiga toxin 2. Microb Pathog 2024; 186:106482. [PMID: 38086442 DOI: 10.1016/j.micpath.2023.106482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/13/2023] [Accepted: 11/29/2023] [Indexed: 12/17/2023]
Abstract
BACKGROUND Shiga toxin-producing Escherichia coli is the main cause of post-diarrheal hemolytic uremic syndrome (HUS) which produces acute kidney injury mainly in children, although it can also affect adults. The kidneys are the organs most affected by Shiga toxin type 2 (Stx2) in patients with HUS. However, previous studies in pregnant rats showed that a sublethal dose of Stx2 causes severe damage in the uteroplacental unit and induces abortion, whereas produces mild to moderate renal damage. The aim of the present work was to study the progression of renal injury caused by a sublethal dose of Stx2, as well as renal recovery, in pregnant and non-pregnant rats, and to investigate whether pregnancy physiology may affect renal damage progression mediated by Stx2. METHODS Renal function and histopathology was evaluated in pregnant rats intraperitoneally injected with a sublethal dose of Stx2 (0.5 ng/g bwt) at the early stage of gestation (day 8 of gestation), and results in these rats were compared over time with those observed in non-pregnant female rats injected with the same Stx2 dose. Hence, progression of cell proliferation and dedifferentiation in renal tubular epithelia was also investigated. RESULTS The sublethal dose of Stx2 induced abortion in pregnant rats as well as a significant more extended functional and histological renal injury in non-pregnant rats than in pregnant rats. Stx2 also caused decreased ability to concentrate urine in non-pregnant rats compared to their controls. However, renal water handling in pregnant rats was not altered by Stx2, and was significantly different than in non-pregnant rats. The greatest renal injury in both pregnant and non-pregnant rats was observed at 4 days post-Stx2 injection, and coincided with a significant increase in tubular epithelial proliferation. Expression of mesenchymal marker vimentin in tubular epithelia was consistent with the level of tubular damage, being higher in non-pregnant rats than in pregnant rats. Recovery from Stx2-induced kidney injury was faster in pregnant rats than in non-pregnant rats. CONCLUSIONS Adaptive mechanisms developed during pregnancy such as changes in water handle and renal hemodynamic may contribute to lessen the Stx2-induced renal injury, perhaps at the expense of fetal loss.
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Affiliation(s)
- Lilian K Fischer Sigel
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Médicas, Departamento de Ciencias Fisiológicas, Laboratorio de Fisiología Renal, Buenos Aires, Argentina; Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Buenos Aires, Argentina
| | - Daiana S Sánchez
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Médicas, Departamento de Ciencias Fisiológicas, Laboratorio de Fisiología Renal, Buenos Aires, Argentina; Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Buenos Aires, Argentina
| | - Flavia Sacerdoti
- Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Médicas, Departamento de Ciencias Fisiológicas, Laboratorio de Fisiopatogenia, Buenos Aires, Argentina
| | - Elsa Zotta
- Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Médicas, Departamento de Ciencias Fisiológicas, Laboratorio de Fisiopatogenia, Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Médicas, Departamento de Ciencias Fisiológicas. Laboratorio de Patología, and Facultad de Farmacia y Bioquímica, Cátedra de Fisiopatología, Buenos Aires, Argentina
| | - Claudia Silberstein
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Médicas, Departamento de Ciencias Fisiológicas, Laboratorio de Fisiología Renal, Buenos Aires, Argentina; Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Buenos Aires, Argentina.
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Kellnerová S, Huber S, Massri M, Fleischer V, Losso K, Sarg B, Kremser L, Talasz H, He X, Varrone E, Brigotti M, Ardissino G, Orth-Höller D, Würzner R. Enzymatic Cleavage of Stx2a in the Gut and Identification of Pancreatic Elastase and Trypsin as Possible Main Cleavers. Microorganisms 2023; 11:2487. [PMID: 37894145 PMCID: PMC10609011 DOI: 10.3390/microorganisms11102487] [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: 07/06/2023] [Revised: 09/15/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023] Open
Abstract
Shiga toxins (Stxs), especially the Stx2a subtype, are the major virulence factors involved in enterohemorrhagic Escherichia coli (EHEC)-associated hemolytic uremic syndrome (eHUS), a life-threatening disease causing acute kidney injury, especially in children. After oral transmission and colonization in the gut, EHEC release Stx. Intracellular cleavage of the Stx A subunit, when followed by reduction, boosts the enzymatic activity that causes damage to targeted cells. This cleavage was assumed to be mostly mediated by furin during Stx intracellular trafficking. To investigate whether this cleavage could occur in the intestine, even prior to entering target cells, Stx2a A subunit structure (intact or cleaved) was characterized after its exposure to specific host factors present in human stool. The molecular weight of Stx2a A subunit/fragments was determined by immunoblotting after electrophoretic separation under reducing conditions. In this study, it was demonstrated that Stx2a is cleaved by certain human stool components. Trypsin and chymotrypsin-like elastase 3B (CELA3B), two serine proteases, were identified as potential candidates that can trigger the extracellular cleavage of Stx2a A subunit directly after its secretion by EHEC in the gut. Whether the observed cleavage indeed translates to natural infections and plays a role in eHUS pathogenesis has yet to be determined. If so, it seems likely that a host's protease profile could affect disease development by changing the toxin's biological features.
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Affiliation(s)
- Sára Kellnerová
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Silke Huber
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Mariam Massri
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Verena Fleischer
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Klemens Losso
- Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, 6020 Innsbruck, Austria;
- Department of Food Technology and Nutrition, MCI|The Entrepreneurial School, 6020 Innsbruck, Austria
| | - Bettina Sarg
- Protein Core Facility, Institute of Medical Biochemistry, Center of Chemistry and Biomedicine, Medical University of Innsbruck, 6020 Innsbruck, Austria; (B.S.); (L.K.); (H.T.)
| | - Leopold Kremser
- Protein Core Facility, Institute of Medical Biochemistry, Center of Chemistry and Biomedicine, Medical University of Innsbruck, 6020 Innsbruck, Austria; (B.S.); (L.K.); (H.T.)
| | - Heribert Talasz
- Protein Core Facility, Institute of Medical Biochemistry, Center of Chemistry and Biomedicine, Medical University of Innsbruck, 6020 Innsbruck, Austria; (B.S.); (L.K.); (H.T.)
| | - Xiaohua He
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, Albany, CA 74710, USA;
| | - Elisa Varrone
- Department of Medical and Surgical Sciences, School of Medicine, University of Bologna, 40126 Bologna, Italy; (E.V.); (M.B.)
| | - Maurizio Brigotti
- Department of Medical and Surgical Sciences, School of Medicine, University of Bologna, 40126 Bologna, Italy; (E.V.); (M.B.)
| | - Gianluigi Ardissino
- Center for HUS Prevention, Control and Management at Pediatric Nephrology, Dialysis and Transplant Unit, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy;
| | - Dorothea Orth-Höller
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
- MB-LAB–Clinical Microbiology Laboratory, 6020 Innsbruck, Austria
| | - Reinhard Würzner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
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4
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Tang J, Lu X, Zhang T, Feng Y, Xu Q, Li J, Lan Y, Luo H, Zeng L, Xiang Y, Zhang Y, Li Q, Mao X, Tang B, Zeng D. Shiga toxin 2 A-subunit induces mitochondrial damage, mitophagy and apoptosis via the interaction of Tom20 in Caco-2 cells. Heliyon 2023; 9:e20012. [PMID: 37809632 PMCID: PMC10559750 DOI: 10.1016/j.heliyon.2023.e20012] [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: 03/23/2023] [Revised: 08/18/2023] [Accepted: 09/08/2023] [Indexed: 10/10/2023] Open
Abstract
Shiga toxin type 2 (Stx2) is the primary virulence factor produced by Shiga toxin-producing enterohemorrhagic Escherichia coli (STEC), which causes epidemic outbreaks of gastrointestinal sickness and potentially fatal sequela hemolytic uremic syndrome (HUS). Most studies on Stx2-induced apoptosis have been performed with holotoxins, but the mechanism of how the A and B subunits of Stx2 cause apoptosis in cells is not clear. Here, we found that Stx2 A-subunit (Stx2A) induced mitochondrial damage, PINK1/Parkin-dependent mitophagy and apoptosis in Caco-2 cells. PINK1/Parkin-dependent mitophagy caused by Stx2A reduced apoptosis by decreasing the accumulation of reactive oxidative species (ROS). Mechanistically, Stx2A interacts with Tom20 on mitochondria to initiate the translocation of Bax to mitochondria, leading to mitochondrial damage and apoptosis. Overall, these data suggested that Stx2A induces mitochondrial damage, mitophagy and apoptosis via the interaction of Tom20 in Caco-2 cells and that mitophagy caused by Stx2A ameliorates apoptosis by eliminating damaged mitochondria. These findings provide evidence for the potential use of Tom20 inhibition as an anti-Shiga toxin therapy.
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Affiliation(s)
- Jie Tang
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Xiaoxue Lu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Tao Zhang
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Yuyang Feng
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Qiaolin Xu
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Jing Li
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Yuanzhi Lan
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Huaxing Luo
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Linghai Zeng
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Yuanyuan Xiang
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Yan Zhang
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | - Qian Li
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Xuhu Mao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Bin Tang
- Department of Clinical Laboratory, Chongqing University Jiangjin Hospital, School of Medicine, Chongqing University, Jiangjin, Chongqing, 402260, China
| | - Dongzhu Zeng
- Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
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5
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Wi SM, Kim SK, Lee JB, Yoon JW. Acid tolerance of enterohemorrhagic Escherichia coli O157:H7 strain ATCC 43894 and its relationship with a large virulence plasmid pO157. Vet Microbiol 2023; 284:109833. [PMID: 37515979 DOI: 10.1016/j.vetmic.2023.109833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/19/2023] [Accepted: 07/17/2023] [Indexed: 07/31/2023]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a zoonotic pathogen that causes a severe intestinal infection including hemolytic uremic syndrome in humans. Various factors contribute to its pathogenesis, including a large virulence plasmid pO157. This F-like 92-kb plasmid is isolated in virtually all clinical EHEC isolates, and is considered a hallmark of EHEC virulence. A previous report stated that removal of pO157 from EHEC ATCC 43894 induced overexpression of GadAB that are essential in glutamate-dependent acid resistance (GDAR) system, yet the mechanism remains elusive. Based on this observation, we surmised that pO157 is involved in the regulation of GDAR system. We comparatively analyzed 43894 and its pO157-cured (ΔpO157) mutant 277 for i) their acid resistance, ii) changes in the transcriptional profiles and iii) expression of GDAR associated genes/proteins. Survivability of 43894 upon exposure to acidic conditions was significantly lower than the ΔpO157 mutant. In addition, RNA-sequencing revealed that genes involved in GDAR were significantly down-regulated in 43894 when compared to the ΔpO157 mutant. Exogenous expression of GadE in 43894 led to expression of GadAB, suggesting possible intervention of pO157 in GDAR regulation. Despite these findings, reintroduction of pO157 into 277 did not reverted Gad overexpression. Likewise, removing pO157 from 43894 using the plasmid incompatibility method did not induce Gad overexpression as shown in 277. Taken together, the results suggest that variation in acid resistance among EHEC isolates exists, and the large virulence plasmid pO157 has no effect on weak acid resistance phenotype displayed in 43894.
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Affiliation(s)
- Seon Mi Wi
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Se Kye Kim
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Jun Bong Lee
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Jang Won Yoon
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea.
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Saricaoglu B, Gültekin Subaşı B, Karbancioglu-Guler F, Lorenzo JM, Capanoglu E. Phenolic compounds as natural microbial toxin detoxifying agents. Toxicon 2023; 222:106989. [PMID: 36509264 DOI: 10.1016/j.toxicon.2022.106989] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022]
Abstract
Despite the abundance of promising studies, developments, and improvements about the elimination of microbial toxins from food matrices, they are still considered as one of the major food safety problems due to the lack of their complete avoidance even today. Every year, many crops and foodstuffs have to be discarded due to unconstrained contamination and/or production of microbial toxins. Furthermore, the difficulty for the detection of toxin presence and determination of its level in foods may lead to acute or chronic health problems in many individuals. On the other hand, phenolic compounds might be considered as microbial toxin detoxification agents because of their inhibition effect on the toxin synthesis of microorganisms or exhibiting protective effects against varying damaging mechanisms caused by toxins. In this study, the effect of phenolic compounds on the synthesis of bacterial toxins and mycotoxins is comprehensively reviewed. The potential curing effect of phenolic compounds against toxin-induced damages has also been discussed. Consequently, phenolic compounds are indicated as promising, and considerable natural preservatives against toxin damages and their detoxification potentials are pronounced.
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Affiliation(s)
- Beyza Saricaoglu
- Department of Food Engineering, Faculty of Chemical and Metallurgical Engineering, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
| | - Büşra Gültekin Subaşı
- Hafik Kamer Ornek Vocational School, Sivas Cumhuriyet University, 58140, Sivas, Turkey
| | - Funda Karbancioglu-Guler
- Department of Food Engineering, Faculty of Chemical and Metallurgical Engineering, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
| | - Jose Manuel Lorenzo
- Centro Tecnológico de La Carne de Galicia, Parque Tecnológico de Galicia, Avd. Galicia nº 4, San Cibrao das Viñas, 32900 Ourense, Spain; Universidade de Vigo, Área de Tecnoloxía dos Alimentos, Facultade de Ciencias, 32004 Ourense, Spain
| | - Esra Capanoglu
- Department of Food Engineering, Faculty of Chemical and Metallurgical Engineering, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey.
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Hama S, Nakahara M, Watanabe-Takahashi M, Shimizu E, Tsutsuki H, Yahiro K, Nishikawa K. Development of a novel tetravalent peptide that absorbs subtilase cytotoxin by targeting the receptor-binding B-subunit. Biochem Biophys Res Commun 2022; 629:95-100. [PMID: 36115284 DOI: 10.1016/j.bbrc.2022.09.007] [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: 08/23/2022] [Revised: 08/26/2022] [Accepted: 09/02/2022] [Indexed: 11/30/2022]
Abstract
Subtilase cytotoxin (SubAB) is a major virulence factor produced by eae-negative Shiga-toxigenic Escherichia coli (STEC) that can cause fatal systemic complications. SubAB binds to target cells through multivalent interactions between its B-subunit pentamer and receptor molecules such as glycoproteins with a terminal N-glycolylneuraminic acid (Neu5Gc). We screened randomized multivalent peptide libraries synthesized on a cellulose membrane and identified a series of tetravalent peptides that efficiently bind to the receptor-binding region of the SubAB B-subunit pentamer. These peptides competitively inhibited the binding of the B-subunit to a receptor-mimic molecule containing clustered Neu5Gc (Neu5Gc-polymer). We selected the peptide with the highest inhibitory efficacy, FFP-tet, and covalently bound it to beads to synthesize FFP-tet-beads, a highly clustered SubAB absorber that displayed potency to absorb SubAB cytotoxicity through direct binding to the toxin. The efficacy of FFP-tet-beads to absorb SubAB cytotoxicity in solution was similar to that of Neu5Gc-polymer, suggesting that FFP-tet-beads might be an effective therapeutic agent against complications arising from eae-negative STEC infection.
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Affiliation(s)
- Shinichiro Hama
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan
| | - Miki Nakahara
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan
| | - Miho Watanabe-Takahashi
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan
| | - Eiko Shimizu
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan
| | - Hiroyasu Tsutsuki
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, 860-8556, Japan
| | - Kinnosuke Yahiro
- Department of Microbiology and Infection Control Sciences, Kyoto Pharmaceutical University, Kyoto, 607-8414, Japan
| | - Kiyotaka Nishikawa
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0321, Japan.
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Molecular Lipopolysaccharide Di-Vaccine Protects from Shiga-Toxin Producing Epidemic Strains of Escherichia coli O157:H7 and O104:H4. Vaccines (Basel) 2022; 10:vaccines10111854. [DOI: 10.3390/vaccines10111854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/25/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Background: Shiga toxin-producing Escherichia coli (STEC) O157:H7 and O104:H4 strains are important causative agents of food-borne diseases such as hemorrhagic colitis and hemolytic–uremic syndrome, which is the leading cause of kidney failure and death in children under 5 years as well as in the elderly. Methods: the native E. coli O157:H7 and O104:H4 lipopolysaccharides (LPS) were partially deacylated under alkaline conditions to obtain apyrogenic S-LPS with domination of tri-acylated lipid A species—Ac3-S-LPS. Results: intraperitoneal immunization of BALB/c mice with Ac3-S-LPS antigens from E. coli O157:H7 and O104:H4 or combination thereof (di-vaccine) at single doses ranging from 25 to 250 µg induced high titers of serum O-specific IgG (mainly IgG1), protected animals against intraperitoneal challenge with lethal doses of homologous STEC strains (60–100% survival rate) and reduced the E. coli O157:H7 and O104:H4 intestinal colonization under an in vivo murine model (6–8-fold for monovalent Ac3-S-LPS and 10-fold for di-vaccine). Conclusions: Di-vaccine induced both systemic and intestinal anti-colonization immunity in mice simultaneously against two highly virulent human STEC strains. The possibility of creating a multivalent STEC vaccine based on safe Ac3-S-LPS seems to be especially promising due to a vast serotype diversity of pathogenic E. coli.
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A unique peptide-based pharmacophore identifies an inhibitory compound against the A-subunit of Shiga toxin. Sci Rep 2022; 12:11443. [PMID: 35794188 PMCID: PMC9259562 DOI: 10.1038/s41598-022-15316-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/22/2022] [Indexed: 01/09/2023] Open
Abstract
Shiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli (EHEC), can cause fatal systemic complications. Recently, we identified a potent inhibitory peptide that binds to the catalytic A-subunit of Stx. Here, using biochemical structural analysis and X-ray crystallography, we determined a minimal essential peptide motif that occupies the catalytic cavity and is required for binding to the A-subunit of Stx2a, a highly virulent Stx subtype. Molecular dynamics simulations also identified the same motif and allowed determination of a unique pharmacophore for A-subunit binding. Notably, a series of synthetic peptides containing the motif efficiently inhibit Stx2a. In addition, pharmacophore screening and subsequent docking simulations ultimately identified nine Stx2a-interacting molecules out of a chemical compound database consisting of over 7,400,000 molecules. Critically, one of these molecules markedly inhibits Stx2a both in vitro and in vivo, clearly demonstrating the significance of the pharmacophore for identifying therapeutic agents against EHEC infection.
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10
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Eliglustat prevents Shiga toxin 2 cytotoxic effects in human renal tubular epithelial cells. Pediatr Res 2022; 91:1121-1129. [PMID: 34155339 DOI: 10.1038/s41390-021-01622-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 05/03/2021] [Accepted: 05/31/2021] [Indexed: 11/08/2022]
Abstract
BACKGROUND Shiga toxin-producing Escherichia coli is responsible for post-diarrheal (D+) hemolytic uremic syndrome (HUS), which is a cause of acute renal failure in children. The glycolipid globotriaosylceramide (Gb3) is the main receptor for Shiga toxin (Stx) in kidney target cells. Eliglustat (EG) is a specific and potent inhibitor of glucosylceramide synthase, first step of glycosphingolipid biosynthesis, actually used for the treatment of Gaucher's disease. The aim of the present work was to evaluate the efficiency of EG in preventing the damage caused by Stx2 in human renal epithelial cells. METHODS Human renal tubular epithelial cell (HRTEC) primary cultures were pre-treated with different dilutions of EG followed by co-incubation with EG and Stx2 at different times, and cell viability, proliferation, apoptosis, tubulogenesis, and Gb3 expression were assessed. RESULTS In HRTEC, pre-treatments with 50 nmol/L EG for 24 h, or 500 nmol/L EG for 6 h, reduced Gb3 expression and totally prevented the effects of Stx2 on cell viability, proliferation, and apoptosis. EG treatment also allowed the development of tubulogenesis in 3D-HRTEC exposed to Stx2. CONCLUSIONS EG could be a potential therapeutic drug for the prevention of acute kidney injury caused by Stx2. IMPACT For the first time, we have demonstrated that Eliglustat prevents Shiga toxin 2 cytotoxic effects on human renal epithelia, by reducing the expression of the toxin receptor globotriaosylceramide. The present work also shows that Eliglustat prevents Shiga toxin 2 effects on tubulogenesis of renal epithelial cells. Eliglustat, actually used for the treatment of patients with Gaucher's disease, could be a therapeutic strategy to prevent the renal damage caused by Shiga toxin.
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Vasco K, Nohomovich B, Singh P, Venegas-Vargas C, Mosci RE, Rust S, Bartlett P, Norby B, Grooms D, Zhang L, Manning SD. Characterizing the Cattle Gut Microbiome in Farms with a High and Low Prevalence of Shiga Toxin Producing Escherichia coli. Microorganisms 2021; 9:microorganisms9081737. [PMID: 34442815 PMCID: PMC8399351 DOI: 10.3390/microorganisms9081737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/06/2021] [Accepted: 08/12/2021] [Indexed: 12/20/2022] Open
Abstract
Cattle are the main reservoirs of Shiga toxin producing Escherichia coli (STEC), a major foodborne pathogen associated with acute enteric disease and hemolytic-uremic syndrome in humans. A total of 397 beef and dairy cattle from 5 farms were included in this study, of which 660 samples were collected for 16S rRNA gene sequencing. The microbiota of farms with a high-STEC prevalence (HSP) had greater richness compared to those of farms with a low-STEC prevalence (LSP). Longitudinal analyses showed STEC-shedders from LSP farms had higher microbiome diversity; meanwhile, changes in the microbiome composition in HSP farms were independent of the STEC shedding status. Most of the bacterial genera associated with STEC shedding in dairy farms were also correlated with differences in the percentage of forage in diet and risk factors of STEC carriage such as days in milk, number of lactations, and warm temperatures. Identifying factors that alter the gut microbiota and enable STEC colonization in livestock could lead to novel strategies to prevent fecal shedding and the subsequent transmission to humans.
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Affiliation(s)
- Karla Vasco
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA; (K.V.); (B.N.); (P.S.); (R.E.M.); (L.Z.)
| | - Brian Nohomovich
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA; (K.V.); (B.N.); (P.S.); (R.E.M.); (L.Z.)
| | - Pallavi Singh
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA; (K.V.); (B.N.); (P.S.); (R.E.M.); (L.Z.)
| | - Cristina Venegas-Vargas
- Department of Large Animal Clinical Sciences, College Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (C.V.-V.); (P.B.); (B.N.); (D.G.)
| | - Rebekah E. Mosci
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA; (K.V.); (B.N.); (P.S.); (R.E.M.); (L.Z.)
| | - Steven Rust
- Department of Animal Science, Michigan State University, East Lansing, MI 48824, USA;
| | - Paul Bartlett
- Department of Large Animal Clinical Sciences, College Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (C.V.-V.); (P.B.); (B.N.); (D.G.)
| | - Bo Norby
- Department of Large Animal Clinical Sciences, College Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (C.V.-V.); (P.B.); (B.N.); (D.G.)
| | - Daniel Grooms
- Department of Large Animal Clinical Sciences, College Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (C.V.-V.); (P.B.); (B.N.); (D.G.)
| | - Lixin Zhang
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA; (K.V.); (B.N.); (P.S.); (R.E.M.); (L.Z.)
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI 48824, USA
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA; (K.V.); (B.N.); (P.S.); (R.E.M.); (L.Z.)
- Correspondence:
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12
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Identification of a peptide motif that potently inhibits two functionally distinct subunits of Shiga toxin. Commun Biol 2021; 4:538. [PMID: 33972673 PMCID: PMC8111002 DOI: 10.1038/s42003-021-02068-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 03/29/2021] [Indexed: 11/08/2022] Open
Abstract
Shiga toxin (Stx) is a major virulence factor of enterohemorrhagic Escherichia coli, which causes fatal systemic complications. Here, we identified a tetravalent peptide that inhibited Stx by targeting its receptor-binding, B-subunit pentamer through a multivalent interaction. A monomeric peptide with the same motif, however, did not bind to the B-subunit pentamer. Instead, the monomer inhibited cytotoxicity with remarkable potency by binding to the catalytic A-subunit. An X-ray crystal structure analysis to 1.6 Å resolution revealed that the monomeric peptide fully occupied the catalytic cavity, interacting with Glu167 and Arg170, both of which are essential for catalytic activity. Thus, the peptide motif demonstrated potent inhibition of two functionally distinct subunits of Stx.
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13
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Sato W, Watanabe-Takahashi M, Hamabata T, Furukawa K, Funamoto S, Nishikawa K. A nontoxigenic form of Shiga toxin 2 suppresses the production of amyloid β by altering the intracellular transport of amyloid precursor protein through its receptor-binding B-subunit. Biochem Biophys Res Commun 2021; 557:247-253. [PMID: 33894410 DOI: 10.1016/j.bbrc.2021.04.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/05/2021] [Indexed: 11/25/2022]
Abstract
Accumulation of amyloid-β peptide (Aβ) in neuronal cells and in the extracellular regions in the brain is a major cause of Alzheimer's disease (AD); therefore, inhibition of Aβ accumulation offers a promising approach for therapeutic strategies against AD. Aβ is produced by sequential proteolysis of amyloid precursor protein (APP) in late/recycling endosomes after endocytosis of APP located in the plasma membrane. Aβ is then released from cells in a free form or in an exosome-bound form. Shiga toxin (Stx) is a major virulence factor of enterohemorrhagic Escherichia coli. Recently, we found that one of the Stx subtypes, Stx2a, has a unique intracellular transport route after endocytosis through its receptor-binding B-subunit. A part of Stx2a can be transported to late/recycling endosomes and then degraded in a lysosomal acidic compartment, although in general Stx is transported to the Golgi and then to the endoplasmic reticulum in a retrograde manner. In this study, we found that treatment of APP-expressing cells with a mutant Stx2a (mStx2a), lacking cytotoxic activity because of mutations in the catalytic A-subunit, stimulated the transport of APP to the acidic compartment, which led to degradation of APP and a reduction in the amount of Aβ. mStx2a-treatment also inhibited the extracellular release of Aβ. Therefore, mStx2a may provide a new strategy to inhibit the production of Aβ by modulating the intracellular transport of APP.
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Affiliation(s)
- Waka Sato
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan
| | - Miho Watanabe-Takahashi
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan
| | - Takashi Hamabata
- Research Institute, National Center for Global Health and Medicine, Tokyo, 162-8655, Japan
| | - Koichi Furukawa
- Department of Biomedical Sciences, Chubu University College of Life and Health Sciences, Kasugai, 487-8501, Japan
| | - Satoru Funamoto
- Department of Neuropathology, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan
| | - Kiyotaka Nishikawa
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan.
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Kim H, Cho JH, Cho JH, Song M, Shin H, Kim S, Kim ES, Kim HB, Lee JH. Complete genome sequence of Escherichia coli K_EC180, a bacterium producing shiga-like toxin isolated from swine feces. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2021; 63:461-464. [PMID: 33987619 PMCID: PMC8071739 DOI: 10.5187/jast.2021.e38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 11/23/2022]
Abstract
Escherichia coli normally colonizes the lower intestine of
animals and humans, but some serotypes are foodborne pathogens. The
Escherichia coli K_EC180 was isolated from swine feces that
were collected from a weaner pig. In this genome announcement, E.
coli K_EC180 was sequenced using PacBio RS II and Illumina NextSeq
500 platforms. The complete chromosome of E. coli K_EC180 is
composed of one circular chromosome (5,017,281 bp) with 50.4% of guanine +
cytosine (G + C) content, 4,935 of coding sequence (CDS), 88 of tRNA, and 22 of
rRNA genes. The complete genome of E. coli K_EC180 contains the
toxin genes such as shiga-like toxins (stxA and stxB).
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Affiliation(s)
- Hyeri Kim
- Department of Animal Resources Science, Dankook University, Cheonan 31116, Korea
| | - Jae Hyoung Cho
- Department of Animal Resources Science, Dankook University, Cheonan 31116, Korea
| | - Jin Ho Cho
- Division of Food and Animal Science, Chungbuk National University, Cheongju 28644, Korea
| | - Minho Song
- Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, Korea
| | - Hakdong Shin
- Department of Food Science and Biotechnology, College of Life Science, Sejong University, Seoul 05006, Korea
| | - Sheena Kim
- Department of Animal Resources Science, Dankook University, Cheonan 31116, Korea
| | - Eun Sol Kim
- Department of Animal Resources Science, Dankook University, Cheonan 31116, Korea
| | - Hyeun Bum Kim
- Department of Animal Resources Science, Dankook University, Cheonan 31116, Korea
| | - Ju-Hoon Lee
- Department of Food Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Seoul National University, Seoul 08826, Korea
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15
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García A, Fox JG. A One Health Perspective for Defining and Deciphering Escherichia coli Pathogenic Potential in Multiple Hosts. Comp Med 2021; 71:3-45. [PMID: 33419487 PMCID: PMC7898170 DOI: 10.30802/aalas-cm-20-000054] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/17/2020] [Accepted: 09/19/2020] [Indexed: 11/05/2022]
Abstract
E. coli is one of the most common species of bacteria colonizing humans and animals. The singularity of E. coli 's genus and species underestimates its multifaceted nature, which is represented by different strains, each with different combinations of distinct virulence factors. In fact, several E. coli pathotypes, or hybrid strains, may be associated with both subclinical infection and a range of clinical conditions, including enteric, urinary, and systemic infections. E. coli may also express DNA-damaging toxins that could impact cancer development. This review summarizes the different E. coli pathotypes in the context of their history, hosts, clinical signs, epidemiology, and control. The pathotypic characterization of E. coli in the context of disease in different animals, including humans, provides comparative and One Health perspectives that will guide future clinical and research investigations of E. coli infections.
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Key Words
- aa, aggregative adherence
- a/e, attaching and effacing
- aepec, atypical epec
- afa, afimbrial adhesin
- aida-i, adhesin involved in diffuse adherence
- aiec, adherent invasive e. coli
- apec, avian pathogenic e. coli
- atcc, american type culture collection
- bfp, bundle-forming pilus
- cd, crohn disease
- cdt, cytolethal distending toxin gene
- clb, colibactin
- cnf, cytotoxic necrotizing factor
- cs, coli surface (antigens)
- daec, diffusely adhering e. coli
- db, dutch belted
- eae, e. coli attaching and effacing gene
- eaec, enteroaggregative e. coli
- eaf, epec adherence factor (plasmid)
- eahec, entero-aggregative-hemorrhagic e. coli
- east-1, enteroaggregative e. coli heat-stable enterotoxin
- e. coli, escherichia coli
- ed, edema disease
- ehec, enterohemorrhagic e. coli
- eiec, enteroinvasive e. coli
- epec, enteropathogenic e. coli
- esbl, extended-spectrum β-lactamase
- esp, e. coli secreted protein
- etec, enterotoxigenic e. coli
- expec, extraintestinal pathogenic e. coli
- fyua, yersiniabactin receptor gene
- gi, gastrointestinal
- hly, hemolysin
- hus, hemolytic uremic syndrome
- ibd, inflammatory bowel disease
- la, localized adherence
- lee, locus of enterocyte effacement
- lpf, long polar fimbriae
- lt, heat-labile (enterotoxin)
- mlst, multilocus sequence typing
- ndm, new delhi metallo-β-lactamase
- nzw, new zealand white
- pap, pyelonephritis-associated pilus
- pks, polyketide synthase
- sfa, s fimbrial adhesin
- slt, shiga-like toxin
- st, heat-stable (enterotoxin)
- stec, stx-producing e. coli
- stx, shiga toxin
- tepec, typical epec
- upec, uropathogenic e. coli
- uti, urinary tract infection
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Affiliation(s)
- Alexis García
- Molecular Sciences Research Center, University of Puerto Rico, San Juan, Puerto Rico; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts;,
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
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16
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Menge C. The Role of Escherichia coli Shiga Toxins in STEC Colonization of Cattle. Toxins (Basel) 2020; 12:toxins12090607. [PMID: 32967277 PMCID: PMC7551371 DOI: 10.3390/toxins12090607] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 11/20/2022] Open
Abstract
Many cattle are persistently colonized with Shiga toxin-producing Escherichia coli (STEC) and represent a major source of human infections with human-pathogenic STEC strains (syn. enterohemorrhagic E. coli (EHEC)). Intervention strategies most effectively protecting humans best aim at the limitation of bovine STEC shedding. Mechanisms enabling STEC to persist in cattle are only partialy understood. Cattle were long believed to resist the detrimental effects of Shiga toxins (Stxs), potent cytotoxins acting as principal virulence factors in the pathogenesis of human EHEC-associated diseases. However, work by different groups, summarized in this review, has provided substantial evidence that different types of target cells for Stxs exist in cattle. Peripheral and intestinal lymphocytes express the Stx receptor globotriaosylceramide (Gb3syn. CD77) in vitro and in vivo in an activation-dependent fashion with Stx-binding isoforms expressed predominantly at early stages of the activation process. Subpopulations of colonic epithelial cells and macrophage-like cells, residing in the bovine mucosa in proximity to STEC colonies, are also targeted by Stxs. STEC-inoculated calves are depressed in mounting appropriate cellular immune responses which can be overcome by vaccination of the animals against Stxs early in life before encountering STEC. Considering Stx target cells and the resulting effects of Stxs in cattle, which significantly differ from effects implicated in human disease, may open promising opportunities to improve existing yet insufficient measures to limit STEC carriage and shedding by the principal reservoir host.
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Affiliation(s)
- Christian Menge
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, D-07743 Jena, Germany
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17
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Molecular Biology of Escherichia Coli Shiga Toxins' Effects on Mammalian Cells. Toxins (Basel) 2020; 12:toxins12050345. [PMID: 32456125 PMCID: PMC7290813 DOI: 10.3390/toxins12050345] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Shiga toxins (Stxs), syn. Vero(cyto)toxins, are potent bacterial exotoxins and the principal virulence factor of enterohemorrhagic Escherichia coli (EHEC), a subset of Shiga toxin-producing E. coli (STEC). EHEC strains, e.g., strains of serovars O157:H7 and O104:H4, may cause individual cases as well as large outbreaks of life-threatening diseases in humans. Stxs primarily exert a ribotoxic activity in the eukaryotic target cells of the mammalian host resulting in rapid protein synthesis inhibition and cell death. Damage of endothelial cells in the kidneys and the central nervous system by Stxs is central in the pathogenesis of hemolytic uremic syndrome (HUS) in humans and edema disease in pigs. Probably even more important, the toxins also are capable of modulating a plethora of essential cellular functions, which eventually disturb intercellular communication. The review aims at providing a comprehensive overview of the current knowledge of the time course and the consecutive steps of Stx/cell interactions at the molecular level. Intervention measures deduced from an in-depth understanding of this molecular interplay may foster our basic understanding of cellular biology and microbial pathogenesis and pave the way to the creation of host-directed active compounds to mitigate the pathological conditions of STEC infections in the mammalian body.
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18
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Targeting the Early Endosome-to-Golgi Transport of Shiga Toxins as a Therapeutic Strategy. Toxins (Basel) 2020; 12:toxins12050342. [PMID: 32456007 PMCID: PMC7290323 DOI: 10.3390/toxins12050342] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 02/07/2023] Open
Abstract
Shiga toxin (STx) produced by Shigella and closely related Shiga toxin 1 and 2 (STx1 and STx2) synthesized by Shiga toxin-producing Escherichia coli (STEC) are bacterial AB5 toxins. All three toxins target kidney cells and may cause life-threatening renal disease. While Shigella infections can be treated with antibiotics, resistance is increasing. Moreover, antibiotic therapy is contraindicated for STEC, and there are no definitive treatments for STEC-induced disease. To exert cellular toxicity, STx, STx1, and STx2 must undergo retrograde trafficking to reach their cytosolic target, ribosomes. Direct transport from early endosomes to the Golgi apparatus is an essential step that allows the toxins to bypass degradative late endosomes and lysosomes. The essentiality of this transport step also makes it an ideal target for the development of small-molecule inhibitors of toxin trafficking as potential therapeutics. Here, we review the recent advances in understanding the molecular mechanisms of the early endosome-to-Golgi transport of STx, STx1, and STx2, as well as the development of small-molecule inhibitors of toxin trafficking that act at the endosome/Golgi interface.
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19
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Johansson KE, Ståhl AL, Arvidsson I, Loos S, Tontanahal A, Rebetz J, Chromek M, Kristoffersson AC, Johannes L, Karpman D. Shiga toxin signals via ATP and its effect is blocked by purinergic receptor antagonism. Sci Rep 2019; 9:14362. [PMID: 31591425 PMCID: PMC6779916 DOI: 10.1038/s41598-019-50692-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/17/2019] [Indexed: 12/26/2022] Open
Abstract
Shiga toxin (Stx) is the main virulence factor of enterohemorrhagic Escherichia coli (EHEC), that cause gastrointestinal infection leading to hemolytic uremic syndrome. The aim of this study was to investigate if Stx signals via ATP and if blockade of purinergic receptors could be protective. Stx induced ATP release from HeLa cells and in a mouse model. Toxin induced rapid calcium influx into HeLa cells, as well as platelets, and a P2X1 receptor antagonist, NF449, abolished this effect. Likewise, the P2X antagonist suramin blocked calcium influx in Hela cells. NF449 did not affect toxin intracellular retrograde transport, however, cells pre-treated with NF449 exhibited significantly higher viability after exposure to Stx for 24 hours, compared to untreated cells. NF449 protected HeLa cells from protein synthesis inhibition and from Stx-induced apoptosis, assayed by caspase 3/7 activity. The latter effect was confirmed by P2X1 receptor silencing. Stx induced the release of toxin-positive HeLa cell- and platelet-derived microvesicles, detected by flow cytometry, an effect significantly reduced by NF449 or suramin. Suramin decreased microvesicle levels in mice injected with Stx or inoculated with Stx-producing EHEC. Taken together, we describe a novel mechanism of Stx-mediated cellular injury associated with ATP signaling and inhibited by P2X receptor blockade.
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Affiliation(s)
- Karl E Johansson
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Anne-Lie Ståhl
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Ida Arvidsson
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Sebastian Loos
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Ashmita Tontanahal
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Johan Rebetz
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Milan Chromek
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | | | - Ludger Johannes
- Institut Curie, U1143 INSERM, UMR3666 CNRS, Cellular and Chemical Biology unit, Paris, France
| | - Diana Karpman
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden.
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Rescue from Stx2-Producing E. coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice. Mol Ther 2019; 28:100-118. [PMID: 31607541 PMCID: PMC6953779 DOI: 10.1016/j.ymthe.2019.09.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/11/2019] [Accepted: 09/26/2019] [Indexed: 12/17/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection.
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21
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Inhibition of enterohemorrhagic Escherichia coli O157:H7 infection in a gnotobiotic mouse model with pre-colonization by Bacteroides strains. Biomed Rep 2019; 10:175-182. [PMID: 30906546 PMCID: PMC6403472 DOI: 10.3892/br.2019.1193] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/04/2019] [Indexed: 12/11/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 has been known to cause outbreaks of hemorrhagic colitis and hemolytic uremic syndrome. We previously demonstrated that intestinal flora contribute to the prevention of EHEC infection in a mouse model. However, it has not yet been determined whether Bacteroides, a predominant genus in the human intestine, contributes to the prevention of EHEC infection. The aim of the present study was to investigate the effect of Bacteroides fragilis (B. fragilis) and Bacteroides vulgatus (B. vulgatus) on EHEC O157:H7 infection in vivo using gnotobiotic mice. These strains were inoculated into germ-free mice to create a gnotobiotic mouse model. EHEC was inoculated into the mice, which were then monitored for 7 days for any change in symptoms. The mice that had been pre-colonized with the Bacteroides strains did not develop lethal EHEC infection, although several inflammatory symptoms were observed in the B. vulgatus pre-colonized group. However, no inflammatory symptoms were identified in the B. fragilis pre-colonized group. Moreover, B. fragilis exerted an inhibitory effect on enterocyte-like cell apoptosis. B. fragilis protected HT29 cells from apoptosis caused by Shiga toxin. In conclusion, the findings of the present study demonstrated that colonization by Bacteroides strains can inhibit EHEC infection.
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22
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Armstrong CM, Ruth LE, Capobianco JA, Strobaugh TP, Rubio FM, Gehring AG. Detection of Shiga Toxin 2 Produced by Escherichia coli in Foods Using a Novel AlphaLISA. Toxins (Basel) 2018; 10:E422. [PMID: 30360508 PMCID: PMC6265734 DOI: 10.3390/toxins10110422] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/09/2018] [Accepted: 10/17/2018] [Indexed: 12/25/2022] Open
Abstract
Amplified luminescent proximity homogenous assay-linked immunosorbent assay (AlphaLISA) is comprised of a bead-based immunoassay that is used for small molecule detection. In this study, a novel AlphaLISA was developed and optimized for the detection of Shiga-toxin 2 (Stx2). Efficacy and sensitivity trials showed the AlphaLISA could detect ≥0.5 ng/mL of purified Stx2, which was comparable to the industry-standard enzyme-linked immunosorbent assay (ELISA) tests for Stx2 detection. In addition, evaluation of Shiga toxin-producing Escherichia coli (STEC)-inoculated Romaine lettuce and ground beef samples demonstrated that both the AlphaLISA and the ELISA were able to discern uninoculated samples from 1× and 10× diluted samples containing ~10 CFU/mL of STEC enriched in modified tryptic soy broth with mitomycin C for 16 h. Overall, the increased signal-to-noise ratios indicated a more robust signal was produced by the AlphaLISA compared to the ELISA and the delineation of higher toxin concentrations without the need for sample dilution implied a greater dynamic range for the AlphaLISA. Implementation of the newly developed AlphaLISA will allow for more rapid analysis for Stx2 with less manual manipulation, thus improving assay throughput and the ability to automate sample screening while maintaining detection limits of 0.5 ng/mL.
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Affiliation(s)
- Cheryl M Armstrong
- Molecular Characterization of Foodborne Pathogens Research Unit, United States Department of Agriculture, Eastern Regional Research Center, Wyndmoor, PA 19038, USA.
| | | | - Joseph A Capobianco
- Molecular Characterization of Foodborne Pathogens Research Unit, United States Department of Agriculture, Eastern Regional Research Center, Wyndmoor, PA 19038, USA.
| | - Terence P Strobaugh
- Molecular Characterization of Foodborne Pathogens Research Unit, United States Department of Agriculture, Eastern Regional Research Center, Wyndmoor, PA 19038, USA.
| | | | - Andrew G Gehring
- Molecular Characterization of Foodborne Pathogens Research Unit, United States Department of Agriculture, Eastern Regional Research Center, Wyndmoor, PA 19038, USA.
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Watanabe-Takahashi M, Yamasaki S, Murata M, Kano F, Motoyama J, Yamate J, Omi J, Sato W, Ukai H, Shimasaki K, Ikegawa M, Tamura-Nakano M, Yanoshita R, Nishino Y, Miyazawa A, Natori Y, Toyama-Sorimachi N, Nishikawa K. Exosome-associated Shiga toxin 2 is released from cells and causes severe toxicity in mice. Sci Rep 2018; 8:10776. [PMID: 30018364 PMCID: PMC6050230 DOI: 10.1038/s41598-018-29128-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 06/27/2018] [Indexed: 12/20/2022] Open
Abstract
Shiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli (EHEC), is classified into two subgroups, Stx1 and Stx2. Clinical data clearly indicate that Stx2 is associated with more severe toxicity than Stx1, but the molecular mechanism underlying this difference is not fully understood. Here, we found that after being incorporated into target cells, Stx2, can be transported by recycling endosomes, as well as via the regular retrograde transport pathway. However, transport via recycling endosome did not occur with Stx1. We also found that Stx2 is actively released from cells in a receptor-recognizing B-subunit dependent manner. Part of the released Stx2 is associated with microvesicles, including exosome markers (referred to as exo-Stx2), whose origin is in the multivesicular bodies that formed from late/recycling endosomes. Finally, intravenous administration of exo-Stx2 to mice causes more lethality and tissue damage, especially severe renal dysfunction and tubular epithelial cell damage, compared to a free form of Stx2. Thus, the formation of exo-Stx2 might contribute to the severity of Stx2 in vivo, suggesting new therapeutic strategies against EHEC infections.
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Affiliation(s)
- Miho Watanabe-Takahashi
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Shinji Yamasaki
- International Prevention of Epidemics, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Masayuki Murata
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Fumi Kano
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Jun Motoyama
- Laboratory of Developmental Neurobiology, Graduate School of Brain Sciences, Doshisha University, Kyoto, Japan
| | - Jyoji Yamate
- Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Jumpei Omi
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Waka Sato
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Hirofumi Ukai
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Kentaro Shimasaki
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Masaya Ikegawa
- Genomics, Proteomics and Biomedical Functions, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Miwa Tamura-Nakano
- Communal Laboratory, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Ryohei Yanoshita
- Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Tokyo, Japan
| | - Yuri Nishino
- Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | - Atsuo Miyazawa
- Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | - Yasuhiro Natori
- Department of Health Chemistry, School of Pharmacy, Iwate Medical University, Iwate, Japan
| | - Noriko Toyama-Sorimachi
- Department of Molecular Immunology and Inflammation, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Kiyotaka Nishikawa
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan.
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24
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Yamamoto BB, Luz D, Abreu PAE, Gotti TB, Vasconcellos SA, Piazza RMF, Horton DSPQ. Antibodies to Shiga toxins in Brazilian cattle. Toxicon 2017; 133:58-62. [PMID: 28454739 DOI: 10.1016/j.toxicon.2017.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 11/17/2022]
Abstract
Cattle are considered a reservoir of Shiga toxin-producing Escherichia coli (STEC). There is no information about the presence of antibodies against Shiga toxins in Brazilian bovine serum. Using ELISA, all sera tested showed antibodies against the two main STEC virulence factors; Stx1 and Stx2. Neutralizing antibodies against Stx1 and/or Stx2 were detected in all but one serum. In conclusion, our results indicated that these animals had been exposed to STEC producing both toxins.
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Affiliation(s)
- Bruno B Yamamoto
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Daniela Luz
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | | | - Tatiana B Gotti
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Silvio A Vasconcellos
- Laboratório de Zoonoses Bacterianas, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
| | - Roxane M F Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil.
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25
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Zadravec P, Marečková L, Petroková H, Hodnik V, Perišić Nanut M, Anderluh G, Štrukelj B, Malý P, Berlec A. Development of Recombinant Lactococcus lactis Displaying Albumin-Binding Domain Variants against Shiga Toxin 1 B Subunit. PLoS One 2016; 11:e0162625. [PMID: 27606705 PMCID: PMC5015993 DOI: 10.1371/journal.pone.0162625] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/25/2016] [Indexed: 01/06/2023] Open
Abstract
Infections with shiga toxin-producing bacteria, like enterohemorrhagic Escherichia coli and Shigella dysenteriae, represent a serious medical problem. No specific and effective treatment is available for patients with these infections, creating a need for the development of new therapies. Recombinant lactic acid bacterium Lactococcus lactis was engineered to bind Shiga toxin by displaying novel designed albumin binding domains (ABD) against Shiga toxin 1 B subunit (Stx1B) on their surface. Functional recombinant Stx1B was produced in Escherichia coli and used as a target for selection of 17 different ABD variants (named S1B) from the ABD scaffold-derived high-complex combinatorial library in combination with a five-round ribosome display. Two most promising S1Bs (S1B22 and S1B26) were characterized into more details by ELISA, surface plasmon resonance and microscale thermophoresis. Addition of S1Bs changed the subcellular distribution of Stx1B, completely eliminating it from Golgi apparatus most likely by interfering with its retrograde transport. All ABD variants were successfully displayed on the surface of L. lactis by fusing to the Usp45 secretion signal and to the peptidoglycan-binding C terminus of AcmA. Binding of Stx1B by engineered lactococcal cells was confirmed using flow cytometry and whole cell ELISA. Lactic acid bacteria prepared in this study are potentially useful for the removal of Shiga toxin from human intestine.
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Affiliation(s)
- Petra Zadravec
- Department of Biotechnology, Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
- The Chair of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI-1000, Ljubljana, Slovenia
| | - Lucie Marečková
- Laboratory of Ligand Engineering, Institute of Biotechnology CAS, v. v. i., BIOCEV Research Center, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Hana Petroková
- Laboratory of Ligand Engineering, Institute of Biotechnology CAS, v. v. i., BIOCEV Research Center, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Vesna Hodnik
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
- National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia
| | - Milica Perišić Nanut
- Department of Biotechnology, Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
| | - Gregor Anderluh
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
- National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia
| | - Borut Štrukelj
- Department of Biotechnology, Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
- The Chair of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI-1000, Ljubljana, Slovenia
| | - Petr Malý
- Laboratory of Ligand Engineering, Institute of Biotechnology CAS, v. v. i., BIOCEV Research Center, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Aleš Berlec
- Department of Biotechnology, Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
- * E-mail:
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Affinity-Based Screening of Tetravalent Peptides Identifies Subtype-Selective Neutralizers of Shiga Toxin 2d, a Highly Virulent Subtype, by Targeting a Unique Amino Acid Involved in Its Receptor Recognition. Infect Immun 2016; 84:2653-61. [PMID: 27382021 DOI: 10.1128/iai.00149-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/24/2016] [Indexed: 12/11/2022] Open
Abstract
Shiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli (EHEC), can be classified into two subgroups, Stx1 and Stx2, each consisting of various closely related subtypes. Stx2 subtypes Stx2a and Stx2d are highly virulent and linked with serious human disorders, such as acute encephalopathy and hemolytic-uremic syndrome. Through affinity-based screening of a tetravalent peptide library, we previously developed peptide neutralizers of Stx2a in which the structure was optimized to bind to the B-subunit pentamer. In this study, we identified Stx2d-selective neutralizers by targeting Asn16 of the B subunit, an amino acid unique to Stx2d that plays an essential role in receptor binding. We synthesized a series of tetravalent peptides on a cellulose membrane in which the core structure was exactly the same as that of peptides in the tetravalent library. A total of nine candidate motifs were selected to synthesize tetravalent forms of the peptides by screening two series of the tetravalent peptides. Five of the tetravalent peptides effectively inhibited the cytotoxicity of Stx2a and Stx2d, and notably, two of the peptides selectively inhibited Stx2d. These two tetravalent peptides bound to the Stx2d B subunit with high affinity dependent on Asn16. The mechanism of binding to the Stx2d B subunit differed from that of binding to Stx2a in that the peptides covered a relatively wide region of the receptor-binding surface. Thus, this highly optimized screening technique enables the development of subtype-selective neutralizers, which may lead to more sophisticated treatments of infections by Stx-producing EHEC.
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Mishra RP, Jain U, Singh RK. Genotypic study of verocytotoxic Escherichia coli isolates from deer by multiplex polymerase chain reaction. Vet World 2016; 9:919-21. [PMID: 27651685 PMCID: PMC5021846 DOI: 10.14202/vetworld.2016.919-921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/22/2016] [Indexed: 11/24/2022] Open
Abstract
AIM This study was planned to study the genotypes of verocytotoxigenic Escherichia coli (VTEC) in fecal samples of deer due to its public health significance. MATERIALS AND METHODS A total of 160 fecal samples of deer were taken from Mathura district and Kanpur Zoo and screened for VTEC genes by polymerase chain reaction (PCR). RESULTS All fecal samples were positive for E. coli. All the E. coli isolates were screened by PCR to detect virulence genes stx1 , stx2 , eaeA, and hlyA. Of these, 15 isolates were found positive for VTEC having one or more genes in different combinations. CONCLUSION Genes such as stx1 , stx2 , eaeA, and hlyA were prevalent in VTEC isolates from feces of deer. The presence of VTEC isolates having virulent genes may pose a threat to public health.
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Affiliation(s)
- Raghavendra Prasad Mishra
- Department of Veterinary Public Health, Veterinary University, UP Pandit Deen Dayal Upadhyaya Veterinary Science University, Mathura, Uttar Pradesh, India
| | - Udit Jain
- Department of Veterinary Public Health, Veterinary University, UP Pandit Deen Dayal Upadhyaya Veterinary Science University, Mathura, Uttar Pradesh, India
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Michelacci V, Orsini M, Knijn A, Delannoy S, Fach P, Caprioli A, Morabito S. Development of a High Resolution Virulence Allelic Profiling (HReVAP) Approach Based on the Accessory Genome of Escherichia coli to Characterize Shiga-Toxin Producing E. coli (STEC). Front Microbiol 2016; 7:202. [PMID: 26941726 PMCID: PMC4763077 DOI: 10.3389/fmicb.2016.00202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 02/05/2016] [Indexed: 11/13/2022] Open
Abstract
Shiga-toxin producing Escherichia coli (STEC) strains possess a large accessory genome composed of virulence genes existing in multiple allelic variants, which sometimes segregate with specific STEC subpopulations. We analyzed the allelic variability of 91 virulence genes of STEC by Real Time PCR followed by melting curves analysis in 713 E. coli strains including 358 STEC. The 91 genes investigated were located on the locus of enterocyte effacement (LEE), OI-57, and OI-122 pathogenicity islands and displayed a total of 476 alleles in the study population. The combinations of the 91 alleles of each strain were termed allelic signatures and used to perform cluster analyses. We termed such an approach High Resolution Virulence Allelic Profiling (HReVAP) and used it to investigate the phylogeny of STEC of multiple serogroups. The dendrograms obtained identified groups of STEC segregating approximately with the serogroups and allowed the identification of subpopulations within the single groups. The study of the allelic signatures provided further evidence of the coevolution of the LEE and OI-122, reflecting the occurrence of their acquisition through a single event. The HReVAP analysis represents a sensitive tool for studying the evolution of LEE-positive STEC.
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Affiliation(s)
- Valeria Michelacci
- European Reference Laboratory for Escherichia coli, Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità Rome, Italy
| | - Massimiliano Orsini
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale Teramo, Italy
| | - Arnold Knijn
- Servizio Informatico, Documentazione, Biblioteca e Attività Editoriali, Istituto Superiore di Sanità Rome, Italy
| | - Sabine Delannoy
- Platform IdentyPath, Food Safety Laboratory, ANSES, Université Paris-Est Maisons-Alfort, France
| | - Patrick Fach
- Platform IdentyPath, Food Safety Laboratory, ANSES, Université Paris-Est Maisons-Alfort, France
| | - Alfredo Caprioli
- European Reference Laboratory for Escherichia coli, Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità Rome, Italy
| | - Stefano Morabito
- European Reference Laboratory for Escherichia coli, Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità Rome, Italy
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Mishra RP, Jain U, Bist B, Verma AK, Kumar A. Prevalence of vero toxic Escherichia coli in fecal samples of domestic as well as wild ruminants in Mathura districts and Kanpur zoo. Vet World 2016; 9:71-4. [PMID: 27051188 PMCID: PMC4819354 DOI: 10.14202/vetworld.2016.71-74] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 12/08/2015] [Accepted: 12/14/2015] [Indexed: 11/16/2022] Open
Abstract
AIM The present study was planned to reveal the prevalence of verocytotoxigenic Escherichia coli (VTEC) in fecal samples of domestic and wild ruminants in Mathura district and Kanpur zoo. MATERIALS AND METHODS A total of 240 fecal samples comprising 60 each of cattle, buffalo, sheep and deer from Mathura districts and Kanpur zoo were screened for the presence of E. coli and VTEC genes positive by polymerase chain reaction (PCR). RESULT Out of 240 fecal samples, 212 E. coli strains were obtained. All the E. coli isolates were screened by PCR to detect virulence genes stx1 , stx2 , eaeA and hlyA. Of these, 25 isolates were identified as VTEC. The prevalence of VTEC in cattle, buffalo, sheep and deer was found 13.4% (8/60), 13.4% (8/60), 6.67% (4/60) and 8.33% (5/60), respectively. CONCLUSION stx1 , stx2 , eaeA and hlyA genes were prevalent in VTEC isolates from feces of cattle, buffalo, sheep and deer population of Mathura districts and Kanpur zoo. The presence of VTEC isolates in this region may pose a threat to public health.
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Affiliation(s)
- Raghavendra Prasad Mishra
- Department of Veterinary Public Health, College of Veterinary Sciences and Animal Husbandry, Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishvidhyalaya Ewam Go-Anusandhan Sansthan, Mathura - 281 001, Uttar Pradesh, India
| | - Udit Jain
- Department of Veterinary Public Health, College of Veterinary Sciences and Animal Husbandry, Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishvidhyalaya Ewam Go-Anusandhan Sansthan, Mathura - 281 001, Uttar Pradesh, India
| | - Basanti Bist
- Department of Veterinary Public Health, College of Veterinary Sciences and Animal Husbandry, Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishvidhyalaya Ewam Go-Anusandhan Sansthan, Mathura - 281 001, Uttar Pradesh, India
| | - Amit Kumar Verma
- Department of Veterinary Epidemiology and Preventive Medicine, College of Veterinary Sciences and Animal Husbandry, Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishvidhyalaya Ewam Go-Anusandhan Sansthan, Mathura - 281 001, Uttar Pradesh, India
| | - Ashok Kumar
- Division of Veterinary Public Health, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
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Brandelli JR, Griener TP, Laing A, Mulvey G, Armstrong GD. The Effects of Shiga Toxin 1, 2 and Their Subunits on Cytokine and Chemokine Expression by Human Macrophage-Like THP-1 Cells. Toxins (Basel) 2015; 7:4054-66. [PMID: 26473922 PMCID: PMC4626720 DOI: 10.3390/toxins7104054] [Citation(s) in RCA: 12] [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: 06/08/2015] [Revised: 09/19/2015] [Accepted: 09/24/2015] [Indexed: 12/01/2022] Open
Abstract
Infection by Shiga toxin (Stx)-producing enterohemorrhagic Escherichia coli (EHEC) results in severe diarrhea, hemorrhagic colitis, and, occasionally, hemolytic-uremic syndrome (HUS). HUS is associated with an increase in pro-inflammatory cytokines and chemokines, many of which are produced by macrophages in the kidneys, indicating that localized host innate immunity likely plays a role in renal pathogenesis. EHEC serotypes may express one or two classes of serologically defined but structurally and functionally-related Shiga toxins called Stx1 and Stx2. Of these, Stx2 appears to be linked to higher rates of HUS than Stx1. To investigate a possible reason for this, we exposed human macrophage-like THP-1 cells to Stx1 or Stx2 and then used the Luminex multiplex system to assess cytokine/chemokine concentrations in culture supernatant solutions. This analysis revealed that, relative to Stx1, Stx2 significantly caused increased expression of GRO, G-CSF, IL-1β, IL-8 and TNFα in macrophage-like THP-1 cells. This was determined to not be due to a difference in cytotoxicity since both Stx1 and Stx2 displayed similar cytotoxic activities on macrophage-like THP-1 cells. These observations indicate that, in vitro, Stx2 can provoke a greater pro-inflammatory response than Stx1 in macrophages and provides a possible partial explanation for higher rates of HUS in patients infected with EHEC strains expressing Stx2. To begin to determine a mechanism for Shiga toxin-mediated cytokine production, we exposed macrophage-like THP-1 cells to Stx1 or Stx2 A and B subunits. Luminex analysis of cytokines in cell culture supernatant solutions demonstrated that neither subunit alone induced a cytokine response in THP-1 cells.
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Affiliation(s)
- Jeremy R Brandelli
- Department of Microbiology, Immunology, and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - Thomas P Griener
- Department of Microbiology, Immunology, and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - Austin Laing
- Department of Microbiology, Immunology, and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - George Mulvey
- Department of Microbiology, Immunology, and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - Glen D Armstrong
- Department of Microbiology, Immunology, and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada.
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Baicalin inhibits the lethality of Shiga-like toxin 2 in mice. Antimicrob Agents Chemother 2015; 59:7054-60. [PMID: 26349825 DOI: 10.1128/aac.01416-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/02/2015] [Indexed: 12/22/2022] Open
Abstract
Shiga-like toxins (Stxs), produced by pathogenic Escherichia coli, are a major virulence factor involved in severe diseases in human and animals. These toxins are ribosome-inactivating proteins, and treatment for diseases caused by them is not available. Therefore, there is an urgent need for agents capable of effectively targeting this lethal toxin. In this study, we identified baicalin, a flavonoid compound used in Chinese traditional medicine, as a compound against Shiga-like toxin 2 (Stx2). We found that baicalin significantly improves renal function and reduces Stx2-induced lethality in mice. Further experiments revealed that baicalin induces the formation of oligomers by the toxin by direct binding. We also identified the residues important for such interactions and analyzed their roles in binding baicalin by biophysical and biochemical analyses. Our results establish baicalin as a candidate compound for the development of therapeutics against diseases caused by Stxs.
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Upadhyay A, Mooyottu S, Yin H, Nair MS, Bhattaram V, Venkitanarayanan K. Inhibiting Microbial Toxins Using Plant-Derived Compounds and Plant Extracts. MEDICINES (BASEL, SWITZERLAND) 2015; 2:186-211. [PMID: 28930207 PMCID: PMC5456214 DOI: 10.3390/medicines2030186] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 06/07/2023]
Abstract
Many pathogenic bacteria and fungi produce potentially lethal toxins that cause cytotoxicity or impaired cellular function either at the site of colonization or other locations in the body through receptor-mediated interactions. Various factors, including biotic and abiotic environments, competing microbes, and chemical cues affect toxin expression in these pathogens. Recent work suggests that several natural compounds can modulate toxin production in pathogenic microbes. However, studies explaining the mechanistic basis for their effect are scanty. This review discusses the potential of various plant-derived compounds for reducing toxin production in foodborne and other microbes. In addition, studies highlighting their anti-toxigenic mechanism(s) are discussed.
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Affiliation(s)
- Abhinav Upadhyay
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Shankumar Mooyottu
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Hsinbai Yin
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
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Abstract
Blood group antigens represent polymorphic traits inherited among individuals and populations. At present, there are 34 recognized human blood groups and hundreds of individual blood group antigens and alleles. Differences in blood group antigen expression can increase or decrease host susceptibility to many infections. Blood groups can play a direct role in infection by serving as receptors and/or coreceptors for microorganisms, parasites, and viruses. In addition, many blood group antigens facilitate intracellular uptake, signal transduction, or adhesion through the organization of membrane microdomains. Several blood groups can modify the innate immune response to infection. Several distinct phenotypes associated with increased host resistance to malaria are overrepresented in populations living in areas where malaria is endemic, as a result of evolutionary pressures. Microorganisms can also stimulate antibodies against blood group antigens, including ABO, T, and Kell. Finally, there is a symbiotic relationship between blood group expression and maturation of the gastrointestinal microbiome.
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Affiliation(s)
- Laura Cooling
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
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Protection against Shiga-Toxigenic Escherichia coli by Non-Genetically Modified Organism Receptor Mimic Bacterial Ghosts. Infect Immun 2015; 83:3526-33. [PMID: 26099582 DOI: 10.1128/iai.00669-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/16/2015] [Indexed: 11/20/2022] Open
Abstract
Shiga-toxigenic Escherichia coli (STEC) causes severe gastrointestinal infections in humans that may lead to life-threatening systemic sequelae, such as the hemolytic uremic syndrome (HUS). Rapid diagnosis of STEC infection early in the course of disease opens a window of opportunity for therapeutic intervention, for example, by administration of agents that neutralize Shiga toxin (Stx) in the gut lumen. We previously developed a recombinant bacterium that expresses a mimic of the Stx receptor globotriaosyl ceramide (Gb3) on its surface through modification of the lipopolysaccharide (A. W. Paton, R. Morona, and J. C. Paton, Nat Med 6:265-270, 2000, http://dx.doi.org/10.1038/73111). This construct was highly efficacious in vivo, protecting mice from otherwise fatal STEC disease, but the fact that it is a genetically modified organism (GMO) has been a barrier to clinical development. In the present study, we have overcome this issue by development of Gb3 receptor mimic bacterial ghosts (BGs) that are not classified as GMOs. Gb3-BGs neutralized Stx1 and Stx2 in vitro with high efficiency, whereas alternative Gb3-expressing non-GMO subbacterial particles (minicells and outer membrane blebs) were ineffective. Gb3-BGs were highly efficacious in a murine model of STEC disease. All mice (10/10) treated with Gb3-BGs survived challenge with a highly virulent O113:H21 STEC strain and showed no pathological signs of renal injury. In contrast, 6/10 mice treated with control BGs succumbed to STEC challenge, and survivors exhibited significant weight loss, neutrophilia, and histopathological evidence of renal damage. Thus, Gb3-BGs offer a non-GMO approach to treatment of STEC infection in humans, particularly in an outbreak setting.
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Hattori T, Watanabe-Takahashi M, Ohoka N, Hamabata T, Furukawa K, Nishikawa K, Naito M. Proteasome inhibitors prevent cell death and prolong survival of mice challenged by Shiga toxin. FEBS Open Bio 2015; 5:605-14. [PMID: 26273560 PMCID: PMC4534485 DOI: 10.1016/j.fob.2015.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/05/2015] [Accepted: 06/08/2015] [Indexed: 11/23/2022] Open
Abstract
Shiga toxin (Stx) rapidly reduces the level of short-lived anti-apoptotic proteins. Stx induces activation of caspase 9 and apoptosis. Proteasome inhibitors prevent the reduction of anti-apoptotic proteins. Proteasome inhibitors suppress Stx-induced apoptosis. Bortezomib prolongs the survival of mice challenged with a lethal dose of Stx.
Shiga toxin (Stx) causes fatal systemic complications. Stx induces apoptosis, but the mechanism of which is unclear. We report that Stx induced rapid reduction of short-lived anti-apoptotic proteins followed by activation of caspase 9 and the progression of apoptosis. Proteasome inhibitors prevented the reduction of anti-apoptotic proteins, and inhibited caspase activation and apoptosis, suggesting that the reduction of anti-apoptotic proteins is a prerequisite for Stx-induced apoptosis. A clinically approved proteasome inhibitor, bortezomib, prolonged the survival of mice challenged by Stx. These results imply that proteasome inhibition may be a novel approach to prevent the fatal effects of Stx.
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Key Words
- Apoptosis
- Apoptosis inhibitory proteins
- BRZ, bortezomib
- CHX, cycloheximide
- ER, endoplasmic reticulum
- FLIP, FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein
- Mcl-1, myeloid cell leukemia 1
- PARP, Poly(ADP-ribose) polymerase
- PI, propidium iodide
- Proteasome
- Proteasome inhibitor
- STEC, Shiga toxin-producing Escherichia coli
- Shiga toxin
- Stx, Shiga toxin
- c-IAP1, cellular inhibitor of apoptosis protein 1
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Affiliation(s)
- Takayuki Hattori
- Division of Molecular Target and Gene Therapy Products, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | | | - Nobumichi Ohoka
- Division of Molecular Target and Gene Therapy Products, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Takashi Hamabata
- Research Institute, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
| | - Koichi Furukawa
- Department of Biochemistry II, Nagoya University Graduate School of Medicine, Nagoya 466-0065, Japan
| | - Kiyotaka Nishikawa
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto 610-0394, Japan
| | - Mikihiko Naito
- Division of Molecular Target and Gene Therapy Products, National Institute of Health Sciences, Tokyo 158-8501, Japan
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Identification of a wide range of motifs inhibitory to shiga toxin by affinity-driven screening of customized divalent peptides synthesized on a membrane. Appl Environ Microbiol 2014; 81:1092-100. [PMID: 25452283 DOI: 10.1128/aem.03517-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Shiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli, binds to target cells through a multivalent interaction between its B-subunit pentamer and the cell surface receptor globotriaosylceramide, resulting in a remarkable increase in its binding affinity. This phenomenon is referred to as the "clustering effect." Previously, we developed a multivalent peptide library that can exert the clustering effect and identified Stx neutralizers with tetravalent peptides by screening this library for high-affinity binding to the specific receptor-binding site of the B subunit. However, this technique yielded only a limited number of binding motifs, with some redundancy in amino acid selectivity. In this study, we established a novel technique to synthesize up to 384 divalent peptides whose structures were customized to exert the clustering effect on the B subunit on a single cellulose membrane. By targeting Stx1a, a major Stx subtype, the customized divalent peptides were screened to identify high-affinity binding motifs. The sequences of the peptides were designed based on information obtained from the multivalent peptide library technique. A total of 64 candidate motifs were successfully identified, and 11 of these were selected to synthesize tetravalent forms of the peptides. All of the synthesized tetravalent peptides bound to the B subunit with high affinities and effectively inhibited the cytotoxicity of Stx1a in Vero cells. Thus, the combination of the two techniques results in greatly improved efficiency in identifying biologically active neutralizers of Stx.
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Top-down proteomic identification of Shiga toxin 2 subtypes from Shiga toxin-producing Escherichia coli by matrix-assisted laser desorption ionization-tandem time of flight mass spectrometry. Appl Environ Microbiol 2014; 80:2928-40. [PMID: 24584253 DOI: 10.1128/aem.04058-13] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We have analyzed 26 Shiga toxin-producing Escherichia coli (STEC) strains for Shiga toxin 2 (Stx2) production using matrix-assisted laser desorption ionization (MALDI)-tandem time of flight (TOF-TOF) tandem mass spectrometry (MS/MS) and top-down proteomic analysis. STEC strains were induced to overexpress Stx2 by overnight culturing on solid agar supplemented with either ciprofloxacin or mitomycin C. Harvested cells were lysed by bead beating, and unfractionated bacterial cell lysates were ionized by MALDI. The A2 fragment of the A subunit and the mature B subunit of Stx2 were analyzed by MS/MS. Sequence-specific fragment ions were used to identify amino acid subtypes of Stx2 using top-down proteomic analysis using software developed in-house at the U.S. Department of Agriculture (USDA). Stx2 subtypes (a, c, d, f, and g) were identified on the basis of the mass of the A2 fragment and the B subunit as well as from their sequence-specific fragment ions by MS/MS (postsource decay). Top-down proteomic identification was in agreement with DNA sequencing of the full Stx2 operon (stx2) for all strains. Top-down results were also compared to a bioassay using a Vero-d2EGFP cell line. Our results suggest that top-down proteomic identification is a rapid, highly specific technique for distinguishing Stx2 subtypes.
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Márquez LB, Velázquez N, Repetto HA, Paton AW, Paton JC, Ibarra C, Silberstein C. Effects of Escherichia coli subtilase cytotoxin and Shiga toxin 2 on primary cultures of human renal tubular epithelial cells. PLoS One 2014; 9:e87022. [PMID: 24466317 PMCID: PMC3897771 DOI: 10.1371/journal.pone.0087022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 12/17/2013] [Indexed: 12/21/2022] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) cause post-diarrhea Hemolytic Uremic Syndrome (HUS), which is the most common cause of acute renal failure in children in many parts of the world. Several non-O157 STEC strains also produce Subtilase cytotoxin (SubAB) that may contribute to HUS pathogenesis. The aim of the present work was to examine the cytotoxic effects of SubAB on primary cultures of human cortical renal tubular epithelial cells (HRTEC) and compare its effects with those produced by Shiga toxin type 2 (Stx2), in order to evaluate their contribution to renal injury in HUS. For this purpose, cell viability, proliferation rate, and apoptosis were assayed on HRTEC incubated with SubAB and/or Stx2 toxins. SubAB significantly reduced cell viability and cell proliferation rate, as well as stimulating cell apoptosis in HRTEC cultures in a time dependent manner. However, HRTEC cultures were significantly more sensitive to the cytotoxic effects of Stx2 than those produced by SubAB. No synergism was observed when HRTEC were co-incubated with both SubAB and Stx2. When HRTEC were incubated with the inactive SubAA272B toxin, results were similar to those in untreated control cells. Similar stimulation of apoptosis was observed in Vero cells incubated with SubAB or/and Stx2, compared to HRTEC. In conclusion, primary cultures of HRTEC are significantly sensitive to the cytotoxic effects of SubAB, although, in a lesser extent compared to Stx2.
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Affiliation(s)
- Laura B. Márquez
- Laboratorio de Investigaciones Biomédicas, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay, Buenos Aires, Argentina
| | - Natalia Velázquez
- Laboratorio de Investigaciones Biomédicas, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay, Buenos Aires, Argentina
| | - Horacio A. Repetto
- Departamento de Pediatría, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Adrienne W. Paton
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, S.A., Australia
| | - James C. Paton
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, S.A., Australia
| | - Cristina Ibarra
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Claudia Silberstein
- Laboratorio de Investigaciones Biomédicas, Departamento de Fisiología, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay, Buenos Aires, Argentina
- * E-mail:
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Gupta N, Pons V, Noël R, Buisson DA, Michau A, Johannes L, Gillet D, Barbier J, Cintrat JC. (S)-N-Methyldihydroquinazolinones are the Active Enantiomers of Retro-2 Derived Compounds against Toxins. ACS Med Chem Lett 2014; 5:94-7. [PMID: 24900779 DOI: 10.1021/ml400457j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 12/04/2013] [Indexed: 01/08/2023] Open
Abstract
This study reports the synthesis, chromatographic separation, and pharmacological evaluation of the two enantiomers of a new compound, named Retro-2.1, active against toxins by inhibiting intracellular trafficking via the retrograde route. The absolute configuration of the bioactive enantiomer has been assigned from X-ray diffraction to the (S)-enantiomer. To date, (S)-Retro-2.1 is the most potent molecule to counteract the cytotoxic potential of ricin and Shiga toxin, with EC50 values of 23 and 54 nM, respectively.
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Affiliation(s)
- Neetu Gupta
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Valérie Pons
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Romain Noël
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - David-Alexandre Buisson
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Aurélien Michau
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Ludger Johannes
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Daniel Gillet
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Julien Barbier
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Jean-Christophe Cintrat
- CEA, iBiTec-S/SIMOPRO,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- CEA, iBiTec-S/SCBM,
CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- U1143 INSERM, 75005 Paris, France
- Institut
Curie,
Centre de Recherche, Chemical Biology of Membranes and Therapeutic
Delivery, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
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Oral intoxication of mice with Shiga toxin type 2a (Stx2a) and protection by anti-Stx2a monoclonal antibody 11E10. Infect Immun 2013; 82:1213-21. [PMID: 24379294 DOI: 10.1128/iai.01264-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) strains cause food-borne outbreaks of hemorrhagic colitis and, less commonly, a serious kidney-damaging sequela called the hemolytic uremic syndrome (HUS). Stx, the primary virulence factor expressed by STEC, is an AB5 toxin with two antigenically distinct forms, Stx1a and Stx2a. Although both toxins have similar biological activities, Stx2a is more frequently produced by STEC strains that cause HUS than is Stx1a. Here we asked whether Stx1a and Stx2a act differently when delivered orally by gavage. We found that Stx2a had a 50% lethal dose (LD50) of 2.9 μg, but no morbidity occurred after oral intoxication with up to 157 μg of Stx1a. We also compared several biochemical and histological parameters in mice intoxicated orally versus intraperitoneally with Stx2a. We discovered that both intoxication routes caused similar increases in serum creatinine and blood urea nitrogen, indicative of kidney damage, as well as electrolyte imbalances and weight loss in the animals. Furthermore, kidney sections from Stx2a-intoxicated mice revealed multifocal, acute tubular necrosis (ATN). Of particular note, we detected Stx2a in kidney sections from orally intoxicated mice in the same region as the epithelial cell type in which ATN was detected. Lastly, we showed reduced renal damage, as determined by renal biomarkers and histopathology, and full protection of orally intoxicated mice with monoclonal antibody (MAb) 11E10 directed against the toxin A subunit; conversely, an irrelevant MAb had no therapeutic effect. Orally intoxicated mice could be rescued by MAb 11E10 6 h but not 24 h after Stx2a delivery.
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Proposal for effective treatment of Shiga toxin-producing Escherichia coli infection in mice. Microb Pathog 2013; 65:57-62. [DOI: 10.1016/j.micpath.2013.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 09/26/2013] [Accepted: 09/26/2013] [Indexed: 11/21/2022]
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Autophagy controls an intrinsic host defense to bacteria by promoting epithelial cell survival: a murine model. PLoS One 2013; 8:e81095. [PMID: 24260541 PMCID: PMC3834267 DOI: 10.1371/journal.pone.0081095] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 10/09/2013] [Indexed: 12/15/2022] Open
Abstract
Cell death is a critical host response to regulate the fate of bacterial infections, innate immune responses, and ultimately, disease outcome. Shigellaspp. invade and colonize gut epithelium in human and nonhuman primates but adult mice are naturally resistant to intra-gastric Shigella infection. In this study, however, we found Shigella could invade the terminal ileum of the mouse small intestine by 1 hour after infection and be rapidly cleared within 24 h. These early phase events occurred shortly after oral infection resulting in epithelial shedding, degranulation of Paneth cells, and cell death in the intestine. During this process, autophagy proceeded without any signs of inflammation. In contrast, blocking autophagy in epithelial cells enhanced host cell death, leading to tissue destruction and to inflammation, suggesting that autophagic flow relieves cellular stress associated with host cell death and inflammation. Herein we propose a new concept of “epithelial barrier turnover” as a general intrinsic host defense mechanism that increases survival of host cells and inhibits inflammation against enteric bacterial infections, which is regulated by autophagy.
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Shiga toxin type 2dact displays increased binding to globotriaosylceramide in vitro and increased lethality in mice after activation by elastase. Toxins (Basel) 2013; 5:2074-92. [PMID: 24217397 PMCID: PMC3847715 DOI: 10.3390/toxins5112074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 10/31/2013] [Accepted: 11/04/2013] [Indexed: 01/24/2023] Open
Abstract
Shiga toxin type 2dact (Stx2dact), an Stx2 variant originally identified from Escherichia coli O91:H21 strain B2F1, displays increased cytotoxicity after activation by elastase present in intestinal mucus. Activation is a result of cleavage of two amino acids from the C-terminal tail of the A2 subunit. In this study, we hypothesized that activation leads to increased binding of toxin to its receptor on host cells both in vitro and in vivo. To test this theory, Stx2dact was treated with elastase or buffer alone and then each toxin was assessed for binding to purified globotriaosylceramide (Gb3) in an enzyme-linked immunosorbent assay, or cells in culture by immunofluorescence, or flow cytometry. Elastase- and buffer-treated Stx2dact were also evaluated for binding to mouse kidney tissue and for relative lethality in mice. We found that activated Stx2dact had a greater capacity to bind purified Gb3, cells in culture, and mouse kidney tissue and was more toxic for mice than was non-activated Stx2dact. Thus, one possible mechanism for the augmented cytotoxicity of Stx2dact after activation is its increased capacity to bind target cells, which, in turn, may cause greater lethality of elastase-treated toxin for mice and enhanced virulence for humans of E. coli strains that express Stx2dact.
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Thomas DE, Elliott EJ. Interventions for preventing diarrhea-associated hemolytic uremic syndrome: systematic review. BMC Public Health 2013; 13:799. [PMID: 24007265 PMCID: PMC3844431 DOI: 10.1186/1471-2458-13-799] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 08/26/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hemolytic Uremic Syndrome (HUS) may follow infection with Shiga-toxin-producing organisms, principally E. coli O157: H7 (STEC), causing high morbidity and mortality. Our aim was to identify interventions to prevent diarrhea-associated HUS. METHODS Systematic search of the literature for relevant systematic reviews (SRs), randomised controlled trials (RCTs) and public health guidelines. RESULTS Of 1097 animal and 762 human studies, 18 animal studies (2 SRs, 2 reviews, plus 14 RCTs) and 6 human studies (3 SRs, plus 3 RCTs) met inclusion criteria. E. coli O157: H7 Type III secreted protein vaccination decreased fecal E. coli O157 shedding in cattle (P = 0.002). E. coli O157: H7 siderophore receptor and porin proteins (SRP) vaccines reduced fecal shedding in cows (OR 0.42 (95% CI 0.25 to 0.73) and increased anti-E. coli 0157: H7 SRP antibodies in their calves (P < 0.001). Bacterin vaccines had no effect. Probiotic or sodium chlorate additives in feeds reduced fecal E. coli O157 load as did improved farm hygiene (P < 0.05). Solarization of soil reduced E. coli O157: H7 contamination in the soil (P < 0.05). In an RCT examining the role of antibiotic treatment of E. coli O157: H7 diarrhea, HUS rates were similar in children treated with Trimethoprim-sulfamethoxazole and controls (RR 0.57; 95% CI 0.11 to 2.81). In another RCT, HUS rates were similar in children receiving Synsorb-Pk and placebo (RR 0.93; 95% CI 0.39 to 2.22). In one SR, hand washing reduced diarrhea by 39% in institutions (IRR 0.61; 95% CI 0.40 to 0.92) and 32% in community settings (IRR 0.68; 95% CI 0.52 to 0.90) compared to controls. Guidelines contained recommendations to prevent STEC transmission from animals and environments to humans, including appropriate food preparation, personal hygiene, community education, and control of environmental contamination, food and water quality. CONCLUSIONS Animal carriage of STEC is decreased by vaccination and improved farm practices. Treatment of STEC diarrhea with antibiotics and toxin-binders did not prevent HUS. Public health interventions are the key to preventing STEC-associated diarrhea and HUS.
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Affiliation(s)
- Diana E Thomas
- Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Sydney, Australia
- Centre for Evidence Based Paediatrics Gastroenterology and Nutrition (CEBPGAN), The Sydney Children's Hospitals Network (Westmead), Westmead NSW 2145, Australia
- Kids Research Institute, The Sydney Children's Hospitals Network (Westmead), Westmead NSW 2145, Australia
| | - Elizabeth J Elliott
- Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Sydney, Australia
- Centre for Evidence Based Paediatrics Gastroenterology and Nutrition (CEBPGAN), The Sydney Children's Hospitals Network (Westmead), Westmead NSW 2145, Australia
- Kids Research Institute, The Sydney Children's Hospitals Network (Westmead), Westmead NSW 2145, Australia
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Kang E, Hwang SY, Kwon KH, Kim KY, Kim JH, Park YH. Prevalence and characteristics of Shiga toxin-producing Escherichia coli (STEC) from cattle in Korea between 2010 and 2011. J Vet Sci 2013; 15:369-79. [PMID: 23820205 PMCID: PMC4178138 DOI: 10.4142/jvs.2014.15.3.369] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 02/16/2013] [Indexed: 11/20/2022] Open
Abstract
A total of 156 Shiga-like toxin producing Escherichia coli (STEC) were isolated from fecal samples of Korean native (100/568, 18%) and Holstein dairy cattle (56/524, 11%) in Korea between September 2010 and July 2011. Fifty-two STEC isolates (33%) harbored both of shiga toxin1 (stx1) and shiga toxin2 (stx2) genes encoding enterohemolysin (EhxA) and autoagglutinating adhesion (Saa) were detected by PCR in 83 (53%) and 65 (42%) isolates, respectively. By serotyping, six STEC from native cattle and four STEC from dairy cattle were identified as O-serotypes (O26, O111, O104, and O157) that can cause human disease. Multilocus sequence typing and pulsed-field gel electrophoresis patterns highlighted the genetic diversity of the STEC strains and difference between strains collected during different years. Antimicrobial susceptibility tests showed that the multidrug resistance rate increased from 12% in 2010 to 42% in 2011. Differences between isolates collected in 2010 and 2011 may have resulted from seasonal variations or large-scale slaughtering in Korea performed to control a foot and mouth disease outbreak that occurred in early 2011. However, continuous epidemiologic studies will be needed to understand mechanisms. More public health efforts are required to minimize STEC infection transmitted via dairy products and the prevalence of these bacteria in dairy cattle.
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Affiliation(s)
- Eun Kang
- Department of Microbiology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul 151-742, Korea
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Rossi L, Di Giancamillo A, Reggi S, Domeneghini C, Baldi A, Sala V, Dell'Orto V, Coddens A, Cox E, Fogher C. Expression of verocytotoxic Escherichia coli antigens in tobacco seeds and evaluation of gut immunity after oral administration in mouse model. J Vet Sci 2013; 14:263-70. [PMID: 23820163 PMCID: PMC3788151 DOI: 10.4142/jvs.2013.14.3.263] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 08/31/2012] [Accepted: 10/23/2012] [Indexed: 01/09/2023] Open
Abstract
Verocytotoxic Escherichia (E.) coli strains are responsible for swine oedema disease, which is an enterotoxaemia that causes economic losses in the pig industry. The production of a vaccine for oral administration in transgenic seeds could be an efficient system to stimulate local immunity. This study was conducted to transform tobacco plants for the seed-specific expression of antigenic proteins from a porcine verocytotoxic E. coli strain. Parameters related to an immunological response and possible adverse effects on the oral administration of obtained tobacco seeds were evaluated in a mouse model. Tobacco was transformed via Agrobacteium tumefaciens with chimeric constructs containing structural parts of the major subunit FedA of the F18 adhesive fimbriae and VT2e B-subunit genes under control of a seed specific GLOB promoter. We showed that the foreign Vt2e-B and F18 genes were stably accumulated in storage tissue by the immunostaining method. In addition, Balb-C mice receiving transgenic tobacco seeds via the oral route showed a significant increase in IgA-positive plasma cell presence in tunica propria when compared to the control group with no observed adverse effects. Our findings encourage future studies focusing on swine for evaluation of the protective effects of transformed tobacco seeds against E. coli infection.
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Affiliation(s)
- Luciana Rossi
- Department of Health, Animal Science and Food Safety, Universita di Milano, 20134 Milan,
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Mukhopadhyay S, Redler B, Linstedt AD. Shiga toxin-binding site for host cell receptor GPP130 reveals unexpected divergence in toxin-trafficking mechanisms. Mol Biol Cell 2013; 24:2311-8. [PMID: 23761068 PMCID: PMC3727924 DOI: 10.1091/mbc.e13-01-0057] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Manganese is specifically effective against Shiga toxin (STx) and STx1. STx2 does not bind the manganese-sensitive host cell receptor GPP130, because a histidine/asparagine pair that constitutes the binding site for GPP130 is not conserved. This reveals an unexpected and significant functional divergence in Shiga toxin evolution. Shiga toxicosis is caused by retrograde trafficking of one of three types of Shiga toxin (STx), STx, STx1, or STx2. Trafficking depends on the toxin B subunits, which for STx and STx1 are identical and bind GPP130, a manganese (Mn)-sensitive intracellular trafficking receptor. Elevated Mn down-regulates GPP130, rendering STx/STx1 harmless. Its effectiveness against STx2, however, which is a serious concern in the developed world, is not known. Here we show that Mn-induced GPP130 down-regulation fails to block STx2 trafficking. To shed light on this result, we tested the purified B subunit of STx2 for binding to GPP130 and found that it failed to interact. We then mapped residues at the interface of the GPP130-STx/STx1 complex. In GPP130, binding mapped to a seven-residue stretch in its lumenal stem domain next to the transmembrane domain. This stretch was required for STx/STx1 transport. In STx/STx1, binding mapped to a histidine–asparagine pair on a surface-exposed loop of the toxin B subunit. Significantly, these residues are not conserved in STx2, explaining the lack of effectiveness of Mn against STx2. Together our results imply that STx2 uses an evolutionarily distinct trafficking mechanism and that Mn as a potential therapy should be focused on STx/STx1 outbreaks, which account for the vast majority of cases worldwide.
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Affiliation(s)
- Somshuvra Mukhopadhyay
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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Noel R, Gupta N, Pons V, Goudet A, Garcia-Castillo MD, Michau A, Martinez J, Buisson DA, Johannes L, Gillet D, Barbier J, Cintrat JC. N-Methyldihydroquinazolinone Derivatives of Retro-2 with Enhanced Efficacy against Shiga Toxin. J Med Chem 2013; 56:3404-13. [DOI: 10.1021/jm4002346] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Romain Noel
- CEA, iBiTec-S/SCBM, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Neetu Gupta
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Valérie Pons
- CEA, iBiTec-S/SCBM, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Amélie Goudet
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Maria Daniela Garcia-Castillo
- UMR144 CNRS and Traffic, Signaling,
and Delivery Laboratory, Institut Curie, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Aurélien Michau
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Jennifer Martinez
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | | | - Ludger Johannes
- UMR144 CNRS and Traffic, Signaling,
and Delivery Laboratory, Institut Curie, 26 Rue d’Ulm, 75248 Paris Cedex 05, France
| | - Daniel Gillet
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Julien Barbier
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
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Identification of a peptide-based neutralizer that potently inhibits both Shiga toxins 1 and 2 by targeting specific receptor-binding regions. Infect Immun 2013; 81:2133-8. [PMID: 23545297 DOI: 10.1128/iai.01256-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin (Stx) is a major virulence factor of enterohemorrhagic Escherichia coli that occasionally causes fatal systemic complications. We recently developed a tetravalent peptide (PPP-tet) that neutralizes the cytotoxicity of Stx2 using a multivalent peptide library approach. In this study, we used this technique to identify a series of tetravalent peptides that bound to Stx1, another major Stx family member, with high affinity by targeting one receptor-binding site of the B subunit. One peptide, MMA-tet, markedly inhibited Stx1 and Stx2 cytotoxicity with greater potency than PPP-tet. After forming a complex with Stx1 through its specific receptor-binding region, MMA-tet did not affect vesicular transport of the toxin to the endoplasmic reticulum but substantially rescued inhibition of the protein synthesis induced by Stx1. Oral application of MMA-tet protected mice from a fatal dose of an E. coli O157:H7 strain producing both toxins. MMA-tet may be a promising therapeutic agent against the infection.
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50
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Investigation of encephalopathy caused by Shiga toxin 2c-producing Escherichia coli infection in mice. PLoS One 2013; 8:e58959. [PMID: 23516588 PMCID: PMC3596349 DOI: 10.1371/journal.pone.0058959] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/08/2013] [Indexed: 01/06/2023] Open
Abstract
A large outbreak of Shiga toxin (Stx)-producing enteroaggregative Escherichia coli (EAEC) O104:H4 occurred in northern Germany. From this outbreak, at least 900 patients developed hemolytic uremic syndrome (HUS), resulting in more than 50 deaths. Thirty percent of the HUS patients showed encephalopathy. We previously established a mouse model with encephalopathy associated with blood brain barrier (BBB) damage after oral infection with the Shiga toxin (Stx) 2c-producing Escherichia coli O157: H- strain E32511 (E32511). In this model, we detected high expression of the Stx receptor synthase enzyme, glycosphingolipid globotriaosylceramide (Gb3) synthase, in endothelial cells (ECs) and neurons in the reticular formation of the medulla oblongata by in situ hybridization. Caspase-3 was activated in neurons in the reticular formation of the medulla oblongata and the anterior horn of the spinal cord. Astrocytes (ASTs) were activated in the medulla oblongata and spinal cord, and a decrease in aquaporin 4 around the ECs suggested that BBB integrity was compromised directly by Stx2c or through the activation of ASTs. We also report the effectiveness of azithromycin (AZM) in our model. Moreover, AZM strongly inhibited the release of Stx2c from E32511 in vitro.
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