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Olawole AS, Malahlela MN, Fonkui TY, Marufu MC, Cenci-Goga BT, Grispoldi L, Etter EMC, Tagwireyi WM, Karama M. Occurrence, serotypes and virulence characteristics of Shiga toxin-producing and Enteropathogenic Escherichia coli isolates from dairy cattle in South Africa. World J Microbiol Biotechnol 2024; 40:299. [PMID: 39134916 PMCID: PMC11319423 DOI: 10.1007/s11274-024-04104-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 08/06/2024] [Indexed: 08/15/2024]
Abstract
Shiga toxin-producing and Enteropathogenic Escherichia coli are foodborne pathogens commonly associated with diarrheal disease in humans. This study investigated the presence of STEC and EPEC in 771 dairy cattle fecal samples which were collected from 5 abattoirs and 9 dairy farms in South Africa. STEC and EPEC were detected, isolated and identified using culture and PCR. Furthermore, 339 STEC and 136 EPEC isolates were characterized by serotype and major virulence genes including stx1, stx2, eaeA and hlyA and the presence of eaeA and bfpA in EPEC. PCR screening of bacterial sweeps which were grown from fecal samples revealed that 42.2% and 23.3% were STEC and EPEC positive, respectively. PCR serotyping of 339 STEC and 136 EPEC isolates revealed 53 different STEC and 19 EPEC serotypes, respectively. The three most frequent STEC serotypes were O82:H8, OgX18:H2, and O157:H7. Only 10% of the isolates were classified as "Top 7" STEC serotypes: O26:H2, 0.3%; O26:H11, 3.2%; O103:H8, 0.6%; and O157:H7, 5.9%. The three most frequent EPEC serotypes were O10:H2, OgN9:H28, and O26:H11. The distribution of major virulence genes among the 339 STEC isolates was as follows: stx1, 72.9%; stx2, 85.7%; eaeA, 13.6% and hlyA, 69.9%. All the 136 EPEC isolates were eaeA-positive but bfpA-negative, while 46.5% carried hlyA. This study revealed that dairy cattle are a major reservoir of STEC and EPEC in South Africa. Further comparative studies of cattle and human STEC and EPEC isolates will be needed to determine the role played by dairy cattle STEC and EPEC in the occurrence of foodborne disease in humans.Please kindly check and confirm the country and city name in affiliation [6].This affiliation is correct.Please kindly check and confirm the affiliationsConfirmed. All Affiliations are accurate.
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Affiliation(s)
- Alaba S Olawole
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Mogaugedi N Malahlela
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Thierry Y Fonkui
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Munyaradzi C Marufu
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Beniamino T Cenci-Goga
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa
- Departiment of Veterinary Medicine, Laboratorio Di Ispezione Degli Alimenti Di Origine Animale, University of Perugia, 06126, Perugia, Italy
| | - Luca Grispoldi
- Departiment of Veterinary Medicine, Laboratorio Di Ispezione Degli Alimenti Di Origine Animale, University of Perugia, 06126, Perugia, Italy
| | - Eric M C Etter
- CIRAD, UMR ASTRE, 97170, Petit-Bourg, Guadeloupe, France
- ASTRE, University de Montpellier, CIRAD, INRAE, 34398, Montpellier, France
| | - Whatmore M Tagwireyi
- Clinical Sciences, School of Veterinary Medicine, Ross University, P.O. Box 334, Basseterre, West Indies, St Kitts and Nevis
| | - Musafiri Karama
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa.
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Giordano M, Iacoviello O, Santangelo L, Martino M, Torres D, Carbone V, Scavia G, Loconsole D, Chironna M, Cristofori F, Francavilla R. Gastrointestinal involvement in STEC-associated hemolytic uremic syndrome: 10 years in a pediatric center. Pediatr Nephrol 2024; 39:1885-1891. [PMID: 38189960 PMCID: PMC11026196 DOI: 10.1007/s00467-023-06258-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 12/09/2023] [Accepted: 12/11/2023] [Indexed: 01/09/2024]
Abstract
BACKGROUND The gastrointestinal (GI) tract represents one of the main targets of typical hemolytic uremic syndrome (HUS) in children. In this observational study, we tried to establish (1) the main features of GI complications during STEC-HUS and (2) the relationship between Escherichia coli serotypes and Shiga toxin (Stx) variants with hepatopancreatic involvement. METHODS A total of 79 STEC-HUS patients were admitted to our pediatric nephrology department between January 2012 and June 2021. Evidence of intestinal, hepatobiliary, and pancreatic involvements was reported for each patient, alongside demographic, clinical, and laboratory features. Frequency of gastrointestinal complications across groups of patients infected by specific E. coli serotypes and Stx gene variants was evaluated. RESULTS Six patients developed a bowel complication: two developed rectal prolapse, and four developed bowel perforation which resulted in death for three of them and in bowel stenosis in one patient. Acute pancreatitis was diagnosed in 13 patients. An isolated increase in pancreatic enzymes and/or liver transaminases was observed in 41 and 15 patients, respectively. Biliary sludge was detected in three, cholelithiasis in one. Forty-seven patients developed direct hyperbilirubinemia. Neither E. coli serotypes nor Shiga toxin variants correlated with hepatic or pancreatic involvement. CONCLUSIONS During STEC-HUS, GI complications are common, ranging from self-limited elevation of laboratory markers to bowel perforation, a severe complication with a relevant impact on morbidity and mortality. Hepatopancreatic involvement is frequent, but usually short-lasting and self-limiting.
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Affiliation(s)
- Mario Giordano
- Pediatric Nephrology and Dialysis Unit, Pediatric Hospital Giovanni XXIII - AOU Consorziale Policlinico, Bari, Italy.
| | - Onofrio Iacoviello
- Interdisciplinary Department of Medicine, Pediatric Section, University of Bari "Aldo Moro, " Pediatric Hospital Giovanni XXIII, Bari, Italy
| | - Luisa Santangelo
- Pediatric Nephrology and Dialysis Unit, Pediatric Hospital Giovanni XXIII - AOU Consorziale Policlinico, Bari, Italy
| | - Marida Martino
- Pediatric Nephrology and Dialysis Unit, Pediatric Hospital Giovanni XXIII - AOU Consorziale Policlinico, Bari, Italy
| | - Diletta Torres
- Pediatric Nephrology and Dialysis Unit, Pediatric Hospital Giovanni XXIII - AOU Consorziale Policlinico, Bari, Italy
| | - Vincenza Carbone
- Pediatric Nephrology and Dialysis Unit, Pediatric Hospital Giovanni XXIII - AOU Consorziale Policlinico, Bari, Italy
| | - Gaia Scavia
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore Di Sanità, Rome, Italy
| | - Daniela Loconsole
- Department of Biomedical Sciences and Human Oncology, Hygiene Section, University of Bari "Aldo Moro", Bari, Italy
| | - Maria Chironna
- Department of Biomedical Sciences and Human Oncology, Hygiene Section, University of Bari "Aldo Moro", Bari, Italy
| | - Fernanda Cristofori
- Interdisciplinary Department of Medicine, Pediatric Section, University of Bari "Aldo Moro, " Pediatric Hospital Giovanni XXIII, Bari, Italy
| | - Ruggiero Francavilla
- Interdisciplinary Department of Medicine, Pediatric Section, University of Bari "Aldo Moro, " Pediatric Hospital Giovanni XXIII, Bari, Italy
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Kalalah AA, Koenig SSK, Bono JL, Bosilevac JM, Eppinger M. Pathogenomes and virulence profiles of representative big six non-O157 serogroup Shiga toxin-producing Escherichia coli. Front Microbiol 2024; 15:1364026. [PMID: 38562479 PMCID: PMC10982417 DOI: 10.3389/fmicb.2024.1364026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 02/29/2024] [Indexed: 04/04/2024] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) of non-O157:H7 serotypes are responsible for global and widespread human food-borne disease. Among these serogroups, O26, O45, O103, O111, O121, and O145 account for the majority of clinical infections and are colloquially referred to as the "Big Six." The "Big Six" strain panel we sequenced and analyzed in this study are reference type cultures comprised of six strains representing each of the non-O157 STEC serogroups curated and distributed by the American Type Culture Collection (ATCC) as a resource to the research community under panel number ATCC MP-9. The application of long- and short-read hybrid sequencing yielded closed chromosomes and a total of 14 plasmids of diverse functions. Through high-resolution comparative phylogenomics, we cataloged the shared and strain-specific virulence and resistance gene content and established the close relationship of serogroup O26 and O103 strains featuring flagellar H-type 11. Virulence phenotyping revealed statistically significant differences in the Stx-production capabilities that we found to be correlated to the strain's individual stx-status. Among the carried Stx1a, Stx2a, and Stx2d phages, the Stx2a phage is by far the most responsive upon RecA-mediated phage mobilization, and in consequence, stx2a + isolates produced the highest-level of toxin in this panel. The availability of high-quality closed genomes for this "Big Six" reference set, including carried plasmids, along with the recorded genomic virulence profiles and Stx-production phenotypes will provide a valuable foundation to further explore the plasticity in evolutionary trajectories in these emerging non-O157 STEC lineages, which are major culprits of human food-borne disease.
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Affiliation(s)
- Anwar A. Kalalah
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX, United States
| | - Sara S. K. Koenig
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX, United States
| | - James L. Bono
- U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), U.S. Meat Animal Research Center, Clay Center, NE, United States
| | - Joseph M. Bosilevac
- U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), U.S. Meat Animal Research Center, Clay Center, NE, United States
| | - Mark Eppinger
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX, United States
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Garofalo M, Payros D, Taieb F, Oswald E, Nougayrède JP, Oswald IP. From ribosome to ribotoxins: understanding the toxicity of deoxynivalenol and Shiga toxin, two food borne toxins. Crit Rev Food Sci Nutr 2023:1-13. [PMID: 37862145 DOI: 10.1080/10408398.2023.2271101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
Ribosomes that synthesize proteins are among the most central and evolutionarily conserved organelles. Given the key role of proteins in cellular functions, prokaryotic and eukaryotic pathogens have evolved potent toxins to inhibit ribosomal functions and weaken their host. Many of these ribotoxin-producing pathogens are associated with food. For example, food can be contaminated with bacterial pathogens that produce the ribotoxin Shiga toxin, but also with the fungal ribotoxin deoxynivalenol. Shiga toxin cleaves ribosomal RNA, while deoxynivalenol binds to and inhibits the peptidyl transferase center. Despite their distinct modes of action, both groups of ribotoxins hinder protein translation, but also trigger other comparable toxic effects, which depend or not on the activation of the ribotoxic stress response. Ribotoxic stress response-dependent effects include inflammation and apoptosis, whereas ribotoxic stress response-independent effects include endoplasmic reticulum stress, oxidative stress, and autophagy. For other effects, such as cell cycle arrest and cytoskeleton modulation, the involvement of the ribotoxic stress response is still controversial. Ribotoxins affect one organelle yet induce multiple toxic effects with multiple consequences for the cell. The ribosome can therefore be considered as the cellular "Achilles heel" targeted by food borne ribotoxins. Considering the high toxicity of ribotoxins, they pose a substantial health risk, as humans are highly susceptible to widespread exposure to these toxins through contaminated food sources.
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Affiliation(s)
- Marion Garofalo
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | - Delphine Payros
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | - Frederic Taieb
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | - Eric Oswald
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Toulouse, France
| | | | - Isabelle P Oswald
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
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Garnier A, Brochard K, Kwon T, Sellier-Leclerc AL, Lahoche A, Launay EA, Nobili F, Caillez M, Taque S, Harambat J, Michel-Bourdat G, Guigonis V, Fila M, Cloarec S, Djamal-Dine D, de Parscaux L, Allard L, Salomon R, Ulinski T, Frémeaux-Bacchi V, Morin C, Olivier-Abbal P, Colineaux H, Auriol F, Arnaud C, Kieffer I, Brusq C. Efficacy and Safety of Eculizumab in Pediatric Patients Affected by Shiga Toxin-Related Hemolytic and Uremic Syndrome: A Randomized, Placebo-Controlled Trial. J Am Soc Nephrol 2023; 34:1561-1573. [PMID: 37303085 PMCID: PMC10482062 DOI: 10.1681/asn.0000000000000182] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 04/21/2023] [Indexed: 06/13/2023] Open
Abstract
SIGNIFICANCE STATEMENT Shiga toxin-related hemolytic uremic syndrome (STEC-HUS) is a serious condition, characterized by multiorgan thrombotic microangiopathy, mainly affecting children. Renal involvement is severe, with approximately half of patients requiring dialysis. So far, no specific treatment has been proven efficient in STEC-HUS. The use of eculizumab, a monoclonal antibody inhibiting terminal complement complex, has demonstrated remarkable success in atypical hemolytic uremic syndrome, but its use in uncontrolled studies to treat STEC-HUS has yielded inconsistent results. In this Phase 3 randomized, placebo-controlled trial in 100 pediatric patients with STEC-HUS, the findings did not show efficacy of eculizumab during the acute phase of the disease. However, the results indicated a reduction of renal sequelae in eculizumab-treated patients at 1-year follow-up. Larger prospective studies would be needed to further explore eculizumab as a potential treatment. BACKGROUND Shiga toxin-related hemolytic uremic syndrome (STEC-HUS) in children is a severe condition, resulting in approximately 50% of patients requiring RRT. Furthermore, at least 30% of survivors experience kidney sequelae. Recently, activation of the complement alternative pathway has been postulated as a factor in STEC-HUS pathophysiology, leading to compassionate use of eculizumab, a monoclonal antibody inhibiting the terminal complement complex, in affected patients. Given the lack of therapy for STEC-HUS, a controlled study of eculizumab efficacy in treating this condition is a priority. METHODS We conducted a Phase 3 randomized trial of eculizumab in children with STEC-HUS. Patients were randomly assigned in a 1:1 ratio to receive either eculizumab or placebo during 4 weeks. Follow-up lasted for 1 year. The primary end point was RRT duration <48 hours after randomization. Secondary endpoints included hematologic and extrarenal involvement. RESULTS Baseline characteristics were similar among the 100 patients who underwent randomization. The rate of RRT <48 hours did not differ significantly between the two groups (48% in the placebo versus 38% in the eculizumab group; P = 0.31) or in the course of ARF. The two groups also exhibited similar hematologic evolution and extrarenal manifestations of STEC-HUS. The proportion of patients experiencing renal sequelae at 1 year was lower in the eculizumab group than in the placebo group (43.48% and 64.44%, respectively, P = 0.04). No safety concern was reported. CONCLUSIONS In pediatric patients with STEC-HUS, eculizumab treatment does not appear to be associated with improved renal outcome during acute phase of the disease but may reduce long-term kidney sequelae. CLINICAL TRIALS REGISTRATIONS EUDRACT (2014-001169-28) ClinicalTrials.gov ( NCT02205541 ).
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Affiliation(s)
- Arnaud Garnier
- Department of Pediatric Nephrology, Hôpital des Enfants, CHU Toulouse, Toulouse, France
| | - Karine Brochard
- Department of Pediatric Nephrology, Hôpital des Enfants, CHU Toulouse, Toulouse, France
| | - Theresa Kwon
- Department of Pediatric Nephrology, Hôpital Robert Debré, Paris, France
| | | | - Annie Lahoche
- Department of Pediatric Nephrology, Hôpital Jeanne de Flandre, Lille, France
| | | | - François Nobili
- Department of Pediatric Nephrology, CHU Besançon, Besançon, France
| | - Mathilde Caillez
- Department of Pediatric Nephrology, Hôpital La Timone, Marseille, France
| | - Sophie Taque
- Department of Pediatric Nephrology, CHU Anne de Bretagne, Rennes, France
| | - Jerôme Harambat
- Department of Pediatric Nephrology, CHU Pellegrin, Bordeaux, France
| | | | - Vincent Guigonis
- Department of Pediatric Nephrology, Hôpital de la Mère et de l’Enfant, Limoges, France
| | - Marc Fila
- Department of Pediatric Nephrology, Hôpital Arnaud de Villeneuve, Montpellier, France
| | - Sylvie Cloarec
- Department of Pediatric Nephrology, CHRU Clocheville, Tours, France
| | | | - Loïc de Parscaux
- Department of Pediatrics and Genetics, CHU Morvan, Brest, France
| | - Lise Allard
- Department of Pediatric Nephrology, CHU Angers, Angers, France
| | - Rémi Salomon
- Department of Pediatric Nephrology, Hôpital Necker-Enfants Malades, Paris, France
| | - Tim Ulinski
- Department of Pediatric Nephrology, Hôpital Trousseau, Paris, France
| | | | | | | | | | - Françoise Auriol
- Unit of Pediatric Clinical Research, CIC1436, Hôpital des Enfants, CHU Toulouse, Toulouse, France
| | | | - Isabelle Kieffer
- Unit of Pediatric Clinical Research, CIC1436, Hôpital des Enfants, CHU Toulouse, Toulouse, France
| | - Clara Brusq
- Clinical Epidemiology Unit, CHU Toulouse, Toulouse, France
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Lee KS, Park JY, Jeong YJ, Lee MS. The Fatal Role of Enterohaemorrhagic Escherichia coli Shiga Toxin-associated Extracellular Vesicles in Host Cells. J Microbiol 2023; 61:715-727. [PMID: 37665555 DOI: 10.1007/s12275-023-00066-0] [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: 05/26/2023] [Revised: 05/26/2023] [Accepted: 07/05/2023] [Indexed: 09/05/2023]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a specific subset of Shiga toxin-producing Escherichia coli (STEC) strains that are characterized by their ability to cause bloody diarrhea (hemorrhagic colitis) and potentially life-threatening, extraintestinal complications such as hemolytic uremic syndrome (HUS), which is associated with acute renal failure., contributing to severe clinical outcomes. The Shiga toxins (Stxs), produced by EHEC, are primary virulence factors. These potent cytotoxins are composed of one enzymatically active A subunit (StxA) and five receptor-binding B subunits (StxB). Although the toxins are primarily associated with cytotoxic effects, they also elicit other pathogenic consequences due to their induction of a number of biological processes, including apoptosis through ER-stress, pro-inflammatory responses, autophagy, and post-translational modification (PTM). Moreover, several studies have reported the association between Stxs and extracellular vesicles (EVs), including microvesicles and exosomes, demonstrating that Stx-containing EVs secreted by intoxicated macrophages are taken up by recipient cells, such as toxin-sensitive renal proximal tubular epithelial cells. This mechanism likely contributes to the spreading of Stxs within the host, and may exacerbate gastrointestinal illnesses and kidney dysfunction. In this review, we summarize recent findings relating to the host responses, in different types of cells in vitro and in animal models, mediated by Stxs-containing exosomes. Due to their unique properties, EVs have been explored as therapeutic agents, drug delivery systems, and diagnostic tools. Thus, potential therapeutic applications of EVs in EHEC Stxs-mediated pathogenesis are also briefly reviewed.
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Affiliation(s)
- Kyung-Soo Lee
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Jun-Young Park
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Yu-Jin Jeong
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34113, Republic of Korea.
| | - Moo-Seung Lee
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea.
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34113, Republic of Korea.
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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: 7] [Impact Index Per Article: 3.5] [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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Lu Z, Liu Z, Li X, Qin X, Hong H, Zhou Z, Pieters RJ, Shi J, Wu Z. Nanobody-Based Bispecific Neutralizer for Shiga Toxin-Producing E. coli. ACS Infect Dis 2022; 8:321-329. [PMID: 35015516 DOI: 10.1021/acsinfecdis.1c00456] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Currently, no specific therapeutics are available for foodborne Shiga toxin-producing Escherichia coli (STEC) infections that cause severe gastroenteritis and life-threatening complications of hemolytic uremic syndrome (HUS). As STEC attachment to intestinal epithelium might increase the host absorption of Shiga toxins and severity of the disease, we were inspired to develop a bispecific neutralizer capable of blocking its Shiga toxin and adhesin intimin simultaneously. Two nanobodies against the B subunit of Shiga toxin 2 (Stx2B) and the C terminus of Intimin (IntC280) were genetically fused together as the bispecific neutralizer, and it can be efficiently produced in a conventional E. coli expression system. We demonstrated that each of the nanobody modules in the bispecific format showed increased antigen binding capability and was able to functionally neutralize the binding of Stx2B or IntC280 to the respective host receptors even in the presence of the two virulence factors together. Moreover, the bispecific neutralizer was relatively stable to harsh storage conditions and gastrointestinal pH extremes. Taking into account its easy and economical production and superior pharmaceutical properties, we believe that a nanobody-based bispecific neutralizer would be more favorable and practical to be developed as a therapeutic to fight STEC in the developing world.
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Affiliation(s)
- Zhongkai Lu
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
| | - Zhicheng Liu
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
| | - Xia Li
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
| | - Xinfang Qin
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
| | - Haofei Hong
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
| | - Zhifang Zhou
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
| | - Roland J. Pieters
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Jie Shi
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
| | - Zhimeng Wu
- Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122 Wuxi, China
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Sharma VK, Akavaram S, Bayles DO. Genomewide transcriptional response of Escherichia coli O157:H7 to norepinephrine. BMC Genomics 2022; 23:107. [PMID: 35135480 PMCID: PMC8822769 DOI: 10.1186/s12864-021-08167-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/10/2021] [Indexed: 01/18/2023] Open
Abstract
Background Chemical signaling between a mammalian host and intestinal microbes is health and maintenance of ‘healthy’ intestinal microbiota. Escherichia coli O157:H7 can hijack host- and microbiota-produced chemical signals for survival in a harsh and nutritionally competitive gastrointestinal environment and for intestinal colonization. Norepinephrine (NE) produced by sympathetic neurons of the enteric nervous system has been shown in vitro to induce expression of genes controlling E. coli O157:H7 swimming motility, acid resistance, and adherence to epithelial cells. A previous study used a microarray approach to identify differentially expressed genes in E. coli O157:H7 strain EDL933 in response to NE. To elucidate a comprehensive transcriptional response to NE, we performed RNA-Seq on rRNA-depleted RNA of E. coli O157:H7 strain NADC 6564, an isolate of a foodborne E. coli O157:H7 strain 86–24. The reads generated by RNA-Seq were mapped to NADC 6564 genome using HiSat2. The mapped reads were quantified by htseq-count against the genome of strain NADC 6564. The differentially expressed genes were identified by analyzing quantified reads by DESeq2. Results Of the 585 differentially expressed genes (≥ 2.0-fold; p < 0.05), many encoded pathways promoting ability of E. coli O157:H7 strain NADC 6564 to colonize intestines of carrier animals and to produce disease in an incidental human host through increased adherence to epithelial cells and production of Shiga toxins. In addition, NE exposure also induced the expression of genes encoding pathways conferring prolonged survival at extreme acidity, controlling influx/efflux of specific nutrients/metabolites, and modulating tolerance to various stressors. A correlation was also observed between the EvgS/EvgA signal transduction system and the ability of bacterial cells to survive exposure to high acidity for several hours. Many genes involved in nitrogen, sulfur, and amino acid uptake were upregulated while genes linked to iron (Fe3+) acquisition and transport were downregulated. Conclusion The availability of physiological levels of NE in gastrointestinal tract could serve as an important cue for E. coli O157:H7 to engineer its virulence, stress, and metabolic pathways for colonization in reservoir animals, such as cattle, causing illness in humans, and surviving outside of a host. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08167-z.
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Affiliation(s)
- Vijay K Sharma
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, 50010, USA.
| | - Suryatej Akavaram
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, 50010, USA.,Current address: 4302 TX-332, Freeport, TX, 77541, USA
| | - Darrell O Bayles
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, 50010, USA
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10
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Fitzgerald SF, Lupolova N, Shaaban S, Dallman TJ, Greig D, Allison L, Tongue SC, Evans J, Henry MK, McNeilly TN, Bono JL, Gally DL. Genome structural variation in Escherichia coli O157:H7. Microb Genom 2021; 7. [PMID: 34751643 PMCID: PMC8743559 DOI: 10.1099/mgen.0.000682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The human zoonotic pathogen Escherichia coli O157:H7 is defined by its extensive prophage repertoire including those that encode Shiga toxin, the factor responsible for inducing life-threatening pathology in humans. As well as introducing genes that can contribute to the virulence of a strain, prophage can enable the generation of large-chromosomal rearrangements (LCRs) by homologous recombination. This work examines the types and frequencies of LCRs across the major lineages of the O157:H7 serotype. We demonstrate that LCRs are a major source of genomic variation across all lineages of E. coli O157:H7 and by using both optical mapping and Oxford Nanopore long-read sequencing prove that LCRs are generated in laboratory cultures started from a single colony and that these variants can be recovered from colonized cattle. LCRs are biased towards the terminus region of the genome and are bounded by specific prophages that share large regions of sequence homology associated with the recombinational activity. RNA transcriptional profiling and phenotyping of specific structural variants indicated that important virulence phenotypes such as Shiga-toxin production, type-3 secretion and motility can be affected by LCRs. In summary, E. coli O157:H7 has acquired multiple prophage regions over time that act to continually produce structural variants of the genome. These findings raise important questions about the significance of this prophage-mediated genome contingency to enhance adaptability between environments.
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Affiliation(s)
- Stephen F Fitzgerald
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Nadejda Lupolova
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Sharif Shaaban
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Timothy J Dallman
- Gastrointestinal Bacterial Reference Unit, 61 Colindale Avenue, Public Health England, NW9 5EQ London, UK
| | - David Greig
- Gastrointestinal Bacterial Reference Unit, 61 Colindale Avenue, Public Health England, NW9 5EQ London, UK
| | - Lesley Allison
- Scottish E. coli O157/VTEC Reference Laboratory, Department of Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| | - Sue C Tongue
- Epidemiology Research Unit (Inverness), Department of Veterinary and Animal Science, Northern Faculty, Scotland's Rural College (SRUC), Scotland, IV2 5NA, UK
| | - Judith Evans
- Epidemiology Research Unit (Inverness), Department of Veterinary and Animal Science, Northern Faculty, Scotland's Rural College (SRUC), Scotland, IV2 5NA, UK
| | - Madeleine K Henry
- Epidemiology Research Unit (Inverness), Department of Veterinary and Animal Science, Northern Faculty, Scotland's Rural College (SRUC), Scotland, IV2 5NA, UK
| | - Tom N McNeilly
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, EH26 OPZ, UK
| | - James L Bono
- United States Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, Nebraska, USA
| | - David L Gally
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
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11
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Liu Y, Tian S, Thaker H, Dong M. Shiga Toxins: An Update on Host Factors and Biomedical Applications. Toxins (Basel) 2021; 13:222. [PMID: 33803852 PMCID: PMC8003205 DOI: 10.3390/toxins13030222] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/13/2021] [Accepted: 03/15/2021] [Indexed: 12/18/2022] Open
Abstract
Shiga toxins (Stxs) are classic bacterial toxins and major virulence factors of toxigenic Shigella dysenteriae and enterohemorrhagic Escherichia coli (EHEC). These toxins recognize a glycosphingolipid globotriaosylceramide (Gb3/CD77) as their receptor and inhibit protein synthesis in cells by cleaving 28S ribosomal RNA. They are the major cause of life-threatening complications such as hemolytic uremic syndrome (HUS), associated with severe cases of EHEC infection, which is the leading cause of acute kidney injury in children. The threat of Stxs is exacerbated by the lack of toxin inhibitors and effective treatment for HUS. Here, we briefly summarize the Stx structure, subtypes, in vitro and in vivo models, Gb3 expression and HUS, and then introduce recent studies using CRISPR-Cas9-mediated genome-wide screens to identify the host cell factors required for Stx action. We also summarize the latest progress in utilizing and engineering Stx components for biomedical applications.
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Affiliation(s)
- Yang Liu
- Department of Nephrology, The First Hospital of Jilin University, Changchun 130021, China
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (H.T.)
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Songhai Tian
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (H.T.)
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Hatim Thaker
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (H.T.)
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Min Dong
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (H.T.)
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
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12
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Detzner J, Krojnewski E, Pohlentz G, Steil D, Humpf HU, Mellmann A, Karch H, Müthing J. Shiga Toxin (Stx)-Binding Glycosphingolipids of Primary Human Renal Cortical Epithelial Cells (pHRCEpiCs) and Stx-Mediated Cytotoxicity. Toxins (Basel) 2021; 13:toxins13020139. [PMID: 33673393 PMCID: PMC7918848 DOI: 10.3390/toxins13020139] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 12/12/2022] Open
Abstract
Human kidney epithelial cells are supposed to be directly involved in the pathogenesis of the hemolytic–uremic syndrome (HUS) caused by Shiga toxin (Stx)-producing enterohemorrhagic Escherichia coli (EHEC). The characterization of the major and minor Stx-binding glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer), respectively, of primary human renal cortical epithelial cells (pHRCEpiCs) revealed GSLs with Cer (d18:1, C16:0), Cer (d18:1, C22:0), and Cer (d18:1, C24:1/C24:0) as the dominant lipoforms. Using detergent-resistant membranes (DRMs) and non-DRMs, Gb3Cer and Gb4Cer prevailed in the DRM fractions, suggesting their association with microdomains in the liquid-ordered membrane phase. A preference of Gb3Cer and Gb4Cer endowed with C24:0 fatty acid accompanied by minor monounsaturated C24:1-harboring counterparts was observed in DRMs, whereas the C24:1 fatty acid increased in relation to the saturated equivalents in non-DRMs. A shift of the dominant phospholipid phosphatidylcholine with saturated fatty acids in the DRM to unsaturated species in the non-DRM fractions correlated with the GSL distribution. Cytotoxicity assays gave a moderate susceptibility of pHRCEpiCs to the Stx1a and Stx2a subtypes when compared to highly sensitive Vero-B4 cells. The results indicate that presence of Stx-binding GSLs per se and preferred occurrence in microdomains do not necessarily lead to a high cellular susceptibility towards Stx.
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Affiliation(s)
- Johanna Detzner
- Institute of Hygiene, University of Münster, D-48149 Münster, Germany; (J.D.); (E.K.); (G.P.); (D.S.); (A.M.); (H.K.)
| | - Elisabeth Krojnewski
- Institute of Hygiene, University of Münster, D-48149 Münster, Germany; (J.D.); (E.K.); (G.P.); (D.S.); (A.M.); (H.K.)
| | - Gottfried Pohlentz
- Institute of Hygiene, University of Münster, D-48149 Münster, Germany; (J.D.); (E.K.); (G.P.); (D.S.); (A.M.); (H.K.)
| | - Daniel Steil
- Institute of Hygiene, University of Münster, D-48149 Münster, Germany; (J.D.); (E.K.); (G.P.); (D.S.); (A.M.); (H.K.)
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, University of Münster, D-48149 Münster, Germany;
| | - Alexander Mellmann
- Institute of Hygiene, University of Münster, D-48149 Münster, Germany; (J.D.); (E.K.); (G.P.); (D.S.); (A.M.); (H.K.)
| | - Helge Karch
- Institute of Hygiene, University of Münster, D-48149 Münster, Germany; (J.D.); (E.K.); (G.P.); (D.S.); (A.M.); (H.K.)
| | - Johannes Müthing
- Institute of Hygiene, University of Münster, D-48149 Münster, Germany; (J.D.); (E.K.); (G.P.); (D.S.); (A.M.); (H.K.)
- Correspondence:
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13
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Warr AR, Kuehl CJ, Waldor MK. Shiga toxin remodels the intestinal epithelial transcriptional response to Enterohemorrhagic Escherichia coli. PLoS Pathog 2021; 17:e1009290. [PMID: 33529199 PMCID: PMC7880444 DOI: 10.1371/journal.ppat.1009290] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 02/12/2021] [Accepted: 01/07/2021] [Indexed: 12/22/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that causes diarrheal disease and the potentially lethal hemolytic uremic syndrome. We used an infant rabbit model of EHEC infection that recapitulates many aspects of human intestinal disease to comprehensively assess colonic transcriptional responses to this pathogen. Cellular compartment-specific RNA-sequencing of intestinal tissue from animals infected with EHEC strains containing or lacking Shiga toxins (Stx) revealed that EHEC infection elicits a robust response that is dramatically shaped by Stx, particularly in epithelial cells. Many of the differences in the transcriptional responses elicited by these strains were in genes involved in immune signaling pathways, such as IL23A, and coagulation, including F3, the gene encoding Tissue Factor. RNA FISH confirmed that these elevated transcripts were found almost exclusively in epithelial cells. Collectively, these findings suggest that Stx potently remodels the host innate immune response to EHEC. Enterohemorrhagic Escherichia coli (EHEC) is a potentially lethal foodborne pathogen. During infection, EHEC releases a potent toxin, Shiga toxin (Stx), into the intestine, but there is limited knowledge of how this toxin shapes the host response to infection. We used an infant rabbit model of infection that closely mimics human disease to profile intestinal transcriptomic responses to EHEC infection. Comparisons of the transcriptional responses to infection by strains containing or lacking Stx revealed that this toxin markedly remodels how the epithelial cell compartment responds to infection. Our findings suggest that Stx shapes the intestinal innate immune response to EHEC and provide insight into the complex host-pathogen dialogue that underlies disease.
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Affiliation(s)
- Alyson R. Warr
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Carole J. Kuehl
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Matthew K. Waldor
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Boston, Massachusetts, United States of America
- * E-mail:
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14
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Valid Presumption of Shiga Toxin-Mediated Damage of Developing Erythrocytes in EHEC-Associated Hemolytic Uremic Syndrome. Toxins (Basel) 2020; 12:toxins12060373. [PMID: 32512916 PMCID: PMC7354503 DOI: 10.3390/toxins12060373] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
The global emergence of clinical diseases caused by enterohemorrhagic Escherichia coli (EHEC) is an issue of great concern. EHEC release Shiga toxins (Stxs) as their key virulence factors, and investigations on the cell-damaging mechanisms toward target cells are inevitable for the development of novel mitigation strategies. Stx-mediated hemolytic uremic syndrome (HUS), characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury, is the most severe outcome of an EHEC infection. Hemolytic anemia during HUS is defined as the loss of erythrocytes by mechanical disruption when passing through narrowed microvessels. The formation of thrombi in the microvasculature is considered an indirect effect of Stx-mediated injury mainly of the renal microvascular endothelial cells, resulting in obstructions of vessels. In this review, we summarize and discuss recent data providing evidence that HUS-associated hemolytic anemia may arise not only from intravascular rupture of erythrocytes, but also from the extravascular impairment of erythropoiesis, the development of red blood cells in the bone marrow, via direct Stx-mediated damage of maturing erythrocytes, leading to “non-hemolytic” anemia.
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15
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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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16
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Shimizu M. Pathogenic functions and diagnostic utility of cytokines/chemokines in EHEC-HUS. Pediatr Int 2020; 62:308-315. [PMID: 31742829 DOI: 10.1111/ped.14053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/07/2019] [Accepted: 11/15/2019] [Indexed: 12/13/2022]
Abstract
Hemolytic - uremic syndrome (HUS) is a severe complication of infection by Shiga toxin (STx)-producing enterohemorrhagic Escherichia coli. Hemolytic - uremic syndrome is defined clinically as a triad of non-immune microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injuries. Neurologic complications such as acute encephalopathy are also observed. In humans, endothelial cells, proximal tubular epithelial cells, mesangial cells, podocytes, intestinal epithelial cells, and monocytes / macrophages are susceptible to STx-mediated injury. Shiga toxin induces the secretion of inflammatory cytokines and chemokines from susceptible cells, including tumor necrosis factor-α interleukin (IL)-1, IL-6, and IL-8. These cytokines and chemokines contribute to the pathogenesis of HUS and encephalopathy by enhancing STx-induced cytotoxicity and inducing inflammatory cell infiltration. Serum cytokine/chemokine levels are therefore useful as indicators of disease activity and predictors of progression from acute kidney injury to chronic kidney disease. Anti-inflammation therapy combined with apheresis to remove excessive cytokines / chemokines and methylprednisolone pulse therapy to suppress cytokine/chemokine production may be an effective treatment regimen for severe E. coli-associated HUS. However, this regimen requires careful monitoring of potential side effects, such as infections, thrombus formation, and hypertension.
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Affiliation(s)
- Masaki Shimizu
- Department of Pediatrics, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
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17
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Fitzgerald SF, Beckett AE, Palarea-Albaladejo J, McAteer S, Shaaban S, Morgan J, Ahmad NI, Young R, Mabbott NA, Morrison L, Bono JL, Gally DL, McNeilly TN. Shiga toxin sub-type 2a increases the efficiency of Escherichia coli O157 transmission between animals and restricts epithelial regeneration in bovine enteroids. PLoS Pathog 2019; 15:e1008003. [PMID: 31581229 PMCID: PMC6776261 DOI: 10.1371/journal.ppat.1008003] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/25/2019] [Indexed: 02/06/2023] Open
Abstract
Specific Escherichia coli isolates lysogenised with prophages that express Shiga toxin (Stx) can be a threat to human health, with cattle being an important natural reservoir. In many countries the most severe pathology is associated with enterohaemorrhagic E. coli (EHEC) serogroups that express Stx subtype 2a. In the United Kingdom, phage type (PT) 21/28 O157 strains have emerged as the predominant cause of life-threatening EHEC infections and this phage type commonly encodes both Stx2a and Stx2c toxin types. PT21/28 is also epidemiologically linked to super-shedding (>103 cfu/g of faeces) which is significant for inter-animal transmission and human infection as demonstrated using modelling studies. We demonstrate that Stx2a is the main toxin produced by stx2a+/stx2c+ PT21/28 strains induced with mitomycin C and this is associated with more rapid induction of gene expression from the Stx2a-encoding prophage compared to that from the Stx2c-encoding prophage. Bacterial supernatants containing either Stx2a and/or Stx2c were demonstrated to restrict growth of bovine gastrointestinal organoids with no restriction when toxin production was not induced or prevented by mutation. Isogenic strains that differed in their capacity to produce Stx2a were selected for experimental oral colonisation of calves to assess the significance of Stx2a for both super-shedding and transmission between animals. Restoration of Stx2a expression in a PT21/28 background significantly increased animal-to-animal transmission and the number of sentinel animals that became super-shedders. We propose that while both Stx2a and Stx2c can restrict regeneration of the epithelium, it is the relatively rapid and higher levels of Stx2a induction, compared to Stx2c, that have contributed to the successful emergence of Stx2a+ E. coli isolates in cattle in the last 40 years. We propose a model in which Stx2a enhances E. coli O157 colonisation of in-contact animals by restricting regeneration and turnover of the colonised gastrointestinal epithelium. Enterohaemorrhagic E. coli (EHEC) O157 strains are found in cattle where they are asymptomatic, while human exposure can lead to severe symptoms including bloody diarrhoea and kidney damage due to the activity of Shiga toxin (Stx). The most serious symptoms in humans are associated with isolates that encode Stx subtype 2a. The advantage of these toxins in the animal reservoir is still not clear, however there is experimental evidence implicating Stx with increased bacterial adherence, immune modulation and suppression of predatory protozoa. In this study, the hypothesis that Stx2a is important for super-shedding and calf-to-calf transmission was tested by comparing excretion and transmission dynamics of E. coli O157 strains with and without Stx2a. While Stx2a did not alter excretion levels when calfs were orally challenge, it enabled colonisation of more in contact ‘sentinel’ animals in our transmission model. We show that Stx2a is generally induced more rapidly than Stx2c, resulting in increased levels of Stx2a expression. Both Stx2a and Stx2c were able to restrict cellular proliferation of epithelial cells in cultured bovine enteroids. Taken together, we propose that rapid production of Stx2a and its role in establishing E. coli O157 colonisation in the bovine gastrointestinal tract facilitate effective transmission and have led to its expansion in the cattle E. coli O157 population.
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Affiliation(s)
- Stephen F. Fitzgerald
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
- Moredun Research Institute, Penicuik, United Kingdom
| | - Amy E. Beckett
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
- Moredun Research Institute, Penicuik, United Kingdom
| | | | - Sean McAteer
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
| | - Sharif Shaaban
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
| | - Jason Morgan
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
- Moredun Research Institute, Penicuik, United Kingdom
| | | | - Rachel Young
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
| | - Neil A. Mabbott
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
| | - Liam Morrison
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
| | - James L. Bono
- United States Department of Agriculture, Agricultural Research Service, Nebraska, United States of America
| | - David L. Gally
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Midlothian, United Kingdom
- * E-mail: (DLG); (TNM)
| | - Tom N. McNeilly
- Moredun Research Institute, Penicuik, United Kingdom
- * E-mail: (DLG); (TNM)
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18
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Zoja C, Buelli S, Morigi M. Shiga toxin triggers endothelial and podocyte injury: the role of complement activation. Pediatr Nephrol 2019; 34:379-388. [PMID: 29214442 DOI: 10.1007/s00467-017-3850-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 10/12/2017] [Accepted: 11/10/2017] [Indexed: 02/07/2023]
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) is the offending agent in post-diarrhea-associated hemolytic uremic syndrome (HUS), a disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney failure, with thrombi occluding the renal microvasculature. Endothelial dysfunction has been recognized as the trigger event in the development of microangiopathic processes. Glomerular endothelial cells are susceptible to the toxic effects of Stxs that, via nuclear factor kappa B (NF-κB) activation, induce the expression of genes encoding for adhesion molecules and chemokines, culminating in leukocyte adhesion and platelet thrombus formation on the activated endothelium. Complement activation via the alternative pathway has been seen in patients during the acute phase of STEC-associated HUS. Experimental evidence has highlighted the role of complement proteins in driving glomerular endothelium toward a thrombogenic phenotype. At the glomerular level, podocytes are also an important target of Stx-induced complement activation. Glomerular injury as a consequence of podocyte dysfunction and loss is thus a mechanism that might affect long-term renal outcomes in the disease. New approaches to targeting the complement system may be useful therapeutic options for patients with STEC-HUS.
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Affiliation(s)
- Carlamaria Zoja
- Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via Stezzano, 87, 24126, Bergamo, Italy.
| | - Simona Buelli
- Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via Stezzano, 87, 24126, Bergamo, Italy
| | - Marina Morigi
- Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via Stezzano, 87, 24126, Bergamo, Italy
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Buelli S, Zoja C, Remuzzi G, Morigi M. Complement Activation Contributes to the Pathophysiology of Shiga Toxin-Associated Hemolytic Uremic Syndrome. Microorganisms 2019; 7:microorganisms7010015. [PMID: 30634669 PMCID: PMC6352217 DOI: 10.3390/microorganisms7010015] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/21/2018] [Accepted: 01/07/2019] [Indexed: 02/06/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) infections have become a threat to public health globally because of the severe illnesses that they can trigger, such as hemorrhagic colitis and the post-diarrheal hemolytic uremic syndrome (HUS), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney failure. Glomerular endothelial cells are primary targets of Stx which, after binding to its specific receptor globotriaosylceramide, upregulates proinflammatory proteins involved both in the recruitment and adhesion of leukocytes and thrombus formation at the site of endothelial injury. In this review, we discuss the role of complement activation in promoting glomerular microvascular dysfunction, providing evidence from experimental models and patients with STEC-HUS. Within the glomerulus, an important target for Stx-induced complement activation is the podocyte, a cell type that is in close contact with endothelial cells and participates in maintaining the filtration barrier. Recently, podocyte injury and loss have been indicated as potential risk factors for long-term renal sequelae in patients with STEC-HUS. Therapeutic approaches targeting the complement system, that may be useful options for patients with STEC-HUS, will also be discussed.
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Affiliation(s)
- Simona Buelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
| | - Carlamaria Zoja
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
- L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, 20157 Milan, Italy.
| | - Marina Morigi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
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Eculizumab in the treatment of Shiga toxin haemolytic uraemic syndrome. Pediatr Nephrol 2019; 34:1485-1492. [PMID: 30058046 PMCID: PMC6660499 DOI: 10.1007/s00467-018-4025-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 07/02/2018] [Accepted: 07/11/2018] [Indexed: 12/26/2022]
Abstract
Haemolytic uraemic syndrome (HUS) remains a leading cause of paediatric acute kidney injury (AKI). Haemolytic uraemic syndrome is characterised by the triad of microangiopathic haemolytic anaemia, thrombocytopenia and AKI. In ~ 90% of cases, HUS is a consequence of infection with Shiga toxin-producing E. coli (STEC), most commonly serotype O157:H7. Acute mortality from STEC-HUS is now less than 5%; however, there is significant long-term renal morbidity in one third of survivors. Currently, no specific treatment exists for STEC-HUS. There is growing interest in the role of complement in the pathogenesis of STEC-HUS due to the discovery of inherited and acquired dysregulation of the alternative complement system in the closely related disorder, atypical HUS (aHUS). The treatment of aHUS has been revolutionised by the introduction of the anti-C5 monoclonal antibody, eculizumab. However, the role of complement and anti-complement therapy in STEC-HUS remains unclear. Herein, we review the current evidence of the role of complement in STEC-HUS focusing on the use of eculizumab in this disease.
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Howard-Varona C, Vik DR, Solonenko NE, Li YF, Gazitua MC, Chittick L, Samiec JK, Jensen AE, Anderson P, Howard-Varona A, Kinkhabwala AA, Abedon ST, Sullivan MB. Fighting Fire with Fire: Phage Potential for the Treatment of E. coli O157 Infection. Antibiotics (Basel) 2018; 7:E101. [PMID: 30453470 PMCID: PMC6315980 DOI: 10.3390/antibiotics7040101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/09/2018] [Accepted: 11/14/2018] [Indexed: 02/07/2023] Open
Abstract
Hemolytic⁻uremic syndrome is a life-threating disease most often associated with Shiga toxin-producing microorganisms like Escherichia coli (STEC), including E. coli O157:H7. Shiga toxin is encoded by resident prophages present within this bacterium, and both its production and release depend on the induction of Shiga toxin-encoding prophages. Consequently, treatment of STEC infections tend to be largely supportive rather than antibacterial, in part due to concerns about exacerbating such prophage induction. Here we explore STEC O157:H7 prophage induction in vitro as it pertains to phage therapy-the application of bacteriophages as antibacterial agents to treat bacterial infections-to curtail prophage induction events, while also reducing STEC O157:H7 presence. We observed that cultures treated with strictly lytic phages, despite being lysed, produce substantially fewer Shiga toxin-encoding temperate-phage virions than untreated STEC controls. We therefore suggest that phage therapy could have utility as a prophylactic treatment of individuals suspected of having been recently exposed to STEC, especially if prophage induction and by extension Shiga toxin production is not exacerbated.
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Affiliation(s)
| | - Dean R Vik
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Natalie E Solonenko
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Yueh-Fen Li
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - M Consuelo Gazitua
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Lauren Chittick
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Jennifer K Samiec
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Aubrey E Jensen
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Paige Anderson
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | | | | | - Stephen T Abedon
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Matthew B Sullivan
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH 43210, USA.
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Exeni RA, Fernandez-Brando RJ, Santiago AP, Fiorentino GA, Exeni AM, Ramos MV, Palermo MS. Pathogenic role of inflammatory response during Shiga toxin-associated hemolytic uremic syndrome (HUS). Pediatr Nephrol 2018; 33:2057-2071. [PMID: 29372302 DOI: 10.1007/s00467-017-3876-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 11/01/2017] [Accepted: 12/07/2017] [Indexed: 01/22/2023]
Abstract
Hemolytic uremic syndrome (HUS) is defined as a triad of noninmune microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. The most frequent presentation is secondary to Shiga toxin (Stx)-producing Escherichia coli (STEC) infections, which is termed postdiarrheal, epidemiologic or Stx-HUS, considering that Stx is the necessary etiological factor. After ingestion, STEC colonize the intestine and produce Stx, which translocates across the intestinal epithelium. Once Stx enters the bloodstream, it interacts with renal endothelial and epithelial cells, and leukocytes. This review summarizes the current evidence about the involvement of inflammatory components as central pathogenic factors that could determine outcome of STEC infections. Intestinal inflammation may favor epithelial leakage and subsequent passage of Stx to the systemic circulation. Vascular damage triggered by Stx promotes not only release of thrombin and increased fibrin concentration but also production of cytokines and chemokines by endothelial cells. Recent evidence from animal models and patients strongly indicate that several immune cells types may participate in HUS physiopathology: neutrophils, through release of proteases and reactive oxygen species (ROS); monocytes/macrophages through secretion of cytokines and chemokines. In addition, high levels of Bb factor and soluble C5b-9 (sC5b-9) in plasma as well as complement factors adhered to platelet-leukocyte complexes, microparticles and microvesicles, suggest activation of the alternative pathway of complement. Thus, acute immune response secondary to STEC infection, the Stx stimulatory effect on different immune cells, and inflammatory stimulus secondary to endothelial damage all together converge to define a strong inflammatory status that worsens Stx toxicity and disease.
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Affiliation(s)
- Ramon Alfonso Exeni
- Departamento de Nefrología, Hospital Municipal del Niño, San Justo, Provincia de Buenos Aires, Argentina
| | - Romina Jimena Fernandez-Brando
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental Medicine (IMEX-CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Adriana Patricia Santiago
- Departamento de Nefrología, Hospital Municipal del Niño, San Justo, Provincia de Buenos Aires, Argentina
| | - Gabriela Alejandra Fiorentino
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental Medicine (IMEX-CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
- Laboratorio, Hospital Municipal del Niño, San Justo, Provincia de Buenos Aires, Argentina
| | - Andrea Mariana Exeni
- Servicio de Nefrología, Hospital Austral, Pilar, Provincia de Buenos Aires, Argentina
| | - Maria Victoria Ramos
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental Medicine (IMEX-CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Marina Sandra Palermo
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental Medicine (IMEX-CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina.
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Eculizumab in STEC-HUS: need for a proper randomized controlled trial. Pediatr Nephrol 2018; 33:1277-1281. [PMID: 29774464 DOI: 10.1007/s00467-018-3972-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 10/16/2022]
Abstract
Hemolytic uremic syndrome caused by Shiga toxin-producing E. coli (STEC-HUS) is often associated with a severe morbidity including neurological involvement and a mortality of 1-5%. Although STEC-HUS is often self-limited, improvement of treatment strategies is needed for cases with complications and, among others, plasma exchange/plasmapheresis and use of antibiotics have been advocated. With the availability of the complement blocker eculizumab, now a standard treatment of atypical HUS, several series have addressed its use in STEC-HUS, with variable response; randomized controlled trials are lacking.In this issue of Pediatric Nephrology, Pecheron et al. present a cohort of 33 pediatric patients with severe HUS treated with eculizumab. Neurological involvement was observed in 85% of the patients and 94% required dialysis. Most patients (55%) did not benefit from eculizumab and renal dysfunction as well as neurological sequelae did not resolve. In a subgroup of patients, however, rapid neurological improvement was described. In the post-hoc-defined group of patients with favorable outcome, there was a trend towards more sustained complement inhibition, although this finding was not significant compared to patients with an unfavorable outcome.Because multiple interventions were used and the study did not include any control group, future controlled studies are urgently needed to resolve the debate as to whether eculizumab can be an effective treatment for both prevention and treatment of complications in STEC-HUS.
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Legros N, Dusny S, Humpf HU, Pohlentz G, Karch H, Müthing J. Shiga toxin glycosphingolipid receptors and their lipid membrane ensemble in primary human blood-brain barrier endothelial cells. Glycobiology 2016; 27:99-109. [PMID: 27558838 DOI: 10.1093/glycob/cww090] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 08/17/2016] [Accepted: 08/19/2016] [Indexed: 12/22/2022] Open
Abstract
Shiga toxin (Stx)-mediated injury to microvascular endothelial cells in the brain significantly contributes to the pathogenesis of the hemolytic-uremic syndrome caused by enterohemorrhagic Escherichia coli (EHEC). Stxs are AB5 toxins and the B-pentamers of the two major Stx subtypes Stx1a and Stx2a preferentially bind to the glycosphingolipid (GSL) globotriaosylceramide (Gb3Cer) expressed by human endothelial cells. Here we report on comprehensive structural analysis of the different lipoforms of Gb3Cer (Galα4Galβ4Glcβ1Cer) and globotetraosylceramide (Gb4Cer, GalNAcβ3Galα4Galβ4Glcβ1Cer, the less effective Stx receptor) of primary human brain microvascular endothelial cells and their association with lipid rafts. Detergent-resistant membranes (DRMs), obtained by sucrose density gradient ultracentrifugation, were used as lipid raft-analogous microdomains of the liquid-ordered phase and nonDRM fractions were employed as equivalents for the liquid-disordered phase of cell membranes. Structures of the prevalent lipoforms of Gb3Cer and Gb4Cer were those with Cer (d18:1, C16:0), Cer (d18:1, C22:0) and Cer (d18:1, C24:1/C24:0) determined by electrospray ionization mass spectrometry that was combined with thin-layer chromatography immunodetection using anti-Gb3Cer and anti-Gb4Cer antibodies as well as Stx1a and Stx2a subtypes. Association of Stx receptor GSLs was determined by co-localization with lipid raft-specific membrane protein flotillin-2 and canonical lipid raft marker sphingomyelin with Cer (d18:1, C16:0) and Cer (d18:1, C24:1/C24:0) in the liquid-ordered phase, whereas lyso-phosphatidylcholine was detectable exclusively in the liquid-disordered phase. Defining the precise microdomain structures of primary endothelial cells may help to unravel the initial mechanisms by which Stxs interact with their target cells and will help to develop novel preventive and therapeutic measures for EHEC-mediated diseases.
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Affiliation(s)
- Nadine Legros
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, D-48149 Münster, Germany
| | - Stefanie Dusny
- Institute for Food Chemistry, University of Münster, Corrensstr. 45, D-48149 Münster, Germany
| | - Hans-Ulrich Humpf
- Institute for Food Chemistry, University of Münster, Corrensstr. 45, D-48149 Münster, Germany
| | - Gottfried Pohlentz
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, D-48149 Münster, Germany
| | - Helge Karch
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, D-48149 Münster, Germany
| | - Johannes Müthing
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, D-48149 Münster, Germany .,Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
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25
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Lewis SB, Prior A, Ellis SJ, Cook V, Chan SSM, Gelson W, Schüller S. Flagellin Induces β-Defensin 2 in Human Colonic Ex vivo Infection with Enterohemorrhagic Escherichia coli. Front Cell Infect Microbiol 2016; 6:68. [PMID: 27446815 PMCID: PMC4914554 DOI: 10.3389/fcimb.2016.00068] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/07/2016] [Indexed: 12/19/2022] Open
Abstract
Enterohemorrhagic E.coli (EHEC) is an important foodborne pathogen in the developed world and can cause life-threatening disease particularly in children. EHEC persists in the human gut by adhering intimately to colonic epithelium and forming characteristic attaching/effacing lesions. In this study, we investigated the innate immune response to EHEC infection with particular focus on antimicrobial peptide and protein expression by colonic epithelium. Using a novel human colonic biopsy model and polarized T84 colon carcinoma cells, we found that EHEC infection induced expression of human β-defensin 2 (hBD2), whereas hBD1, hBD3, LL-37, and lysozyme remained unchanged. Infection with specific EHEC deletion mutants demonstrated that this was dependent on flagellin, and apical exposure to purified flagellin was sufficient to stimulate hBD2 and also interleukin (IL)-8 expression ex vivo and in vitro. Flagellin-mediated hBD2 induction was significantly reduced by inhibitors of NF-κB, MAP kinase p38 and JNK but not ERK1/2. Interestingly, IL-8 secretion by polarized T84 cells was vectorial depending on the side of stimulation, and apical exposure to EHEC or flagellin resulted in apical IL-8 release. Our results demonstrate that EHEC only induces a modest immune response in human colonic epithelium characterized by flagellin-dependent induction of hBD2 and low levels of IL-8.
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Affiliation(s)
- Steven B Lewis
- Norwich Medical School, University of East AngliaNorwich, UK; Gut Health and Food Safety Programme, Institute of Food ResearchNorwich, UK
| | - Alison Prior
- Gastroenterology Department, Norfolk and Norwich University Hospital Norwich, UK
| | - Samuel J Ellis
- Norwich Medical School, University of East AngliaNorwich, UK; Gut Health and Food Safety Programme, Institute of Food ResearchNorwich, UK
| | - Vivienne Cook
- Gastroenterology Department, Norfolk and Norwich University Hospital Norwich, UK
| | - Simon S M Chan
- Norwich Medical School, University of East AngliaNorwich, UK; Gastroenterology Department, Norfolk and Norwich University HospitalNorwich, UK
| | - William Gelson
- Gastroenterology Department, Norfolk and Norwich University Hospital Norwich, UK
| | - Stephanie Schüller
- Norwich Medical School, University of East AngliaNorwich, UK; Gut Health and Food Safety Programme, Institute of Food ResearchNorwich, UK
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FDA Escherichia coli Identification (FDA-ECID) Microarray: a Pangenome Molecular Toolbox for Serotyping, Virulence Profiling, Molecular Epidemiology, and Phylogeny. Appl Environ Microbiol 2016; 82:3384-3394. [PMID: 27037122 PMCID: PMC4959244 DOI: 10.1128/aem.04077-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/24/2016] [Indexed: 12/21/2022] Open
Abstract
Most Escherichia coli strains are nonpathogenic. However, for clinical diagnosis and food safety analysis, current identification methods for pathogenic E. coli either are time-consuming and/or provide limited information. Here, we utilized a custom DNA microarray with informative genetic features extracted from 368 sequence sets for rapid and high-throughput pathogen identification. The FDA Escherichia coli Identification (FDA-ECID) platform contains three sets of molecularly informative features that together stratify strain identification and relatedness. First, 53 known flagellin alleles, 103 alleles of wzx and wzy, and 5 alleles of wzm provide molecular serotyping utility. Second, 41,932 probe sets representing the pan-genome of E. coli provide strain-level gene content information. Third, approximately 125,000 single nucleotide polymorphisms (SNPs) of available whole-genome sequences (WGS) were distilled to 9,984 SNPs capable of recapitulating the E. coli phylogeny. We analyzed 103 diverse E. coli strains with available WGS data, including those associated with past foodborne illnesses, to determine robustness and accuracy. The array was able to accurately identify the molecular O and H serotypes, potentially correcting serological failures and providing better resolution for H-nontypeable/nonmotile phenotypes. In addition, molecular risk assessment was possible with key virulence marker identifications. Epidemiologically, each strain had a unique comparative genomic fingerprint that was extended to an additional 507 food and clinical isolates. Finally, a 99.7% phylogenetic concordance was established between microarray analysis and WGS using SNP-level data for advanced genome typing. Our study demonstrates FDA-ECID as a powerful tool for epidemiology and molecular risk assessment with the capacity to profile the global landscape and diversity of E. coli. IMPORTANCE This study describes a robust, state-of-the-art platform developed from available whole-genome sequences of E. coli and Shigella spp. by distilling useful signatures for epidemiology and molecular risk assessment into one assay. The FDA-ECID microarray contains features that enable comprehensive molecular serotyping and virulence profiling along with genome-scale genotyping and SNP analysis. Hence, it is a molecular toolbox that stratifies strain identification and pathogenic potential in the contexts of epidemiology and phylogeny. We applied this tool to strains from food, environmental, and clinical sources, resulting in significantly greater phylogenetic and strain-specific resolution than previously reported for available typing methods.
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Abstract
Shiga toxin (Stx) is the primary cause of severe host responses including renal and central nervous system (CNS) disease in Shiga toxin-producing E. coli (STEC) infections. The interaction of Stx with different eukaryotic cell types is described. Host responses to Stx and bacterial lipopolysaccharide (LPS) are compared as related to the features of the STEC-associated Hemolytic Uremic Syndrome (HUS). Data derived from animal models of HUS and CNS disease, in vivo, and eukaryotic cells, in vitro, are evaluated in relation to HUS disease of humans.
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Murfin KE, Whooley AC, Klassen JL, Goodrich-Blair H. Comparison of Xenorhabdus bovienii bacterial strain genomes reveals diversity in symbiotic functions. BMC Genomics 2015; 16:889. [PMID: 26525894 PMCID: PMC4630870 DOI: 10.1186/s12864-015-2000-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 10/03/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Xenorhabdus bacteria engage in a beneficial symbiosis with Steinernema nematodes, in part by providing activities that help kill and degrade insect hosts for nutrition. Xenorhabdus strains (members of a single species) can display wide variation in host-interaction phenotypes and genetic potential indicating that strains may differ in their encoded symbiosis factors, including secreted metabolites. METHODS To discern strain-level variation among symbiosis factors, and facilitate the identification of novel compounds, we performed a comparative analysis of the genomes of 10 Xenorhabdus bovienii bacterial strains. RESULTS The analyzed X. bovienii draft genomes are broadly similar in structure (e.g. size, GC content, number of coding sequences). Genome content analysis revealed that general classes of putative host-microbe interaction functions, such as secretion systems and toxin classes, were identified in all bacterial strains. In contrast, we observed diversity of individual genes within families (e.g. non-ribosomal peptide synthetase clusters and insecticidal toxin components), indicating the specific molecules secreted by each strain can vary. Additionally, phenotypic analysis indicates that regulation of activities (e.g. enzymes and motility) differs among strains. CONCLUSIONS The analyses presented here demonstrate that while general mechanisms by which X. bovienii bacterial strains interact with their invertebrate hosts are similar, the specific molecules mediating these interactions differ. Our data support that adaptation of individual bacterial strains to distinct hosts or niches has occurred. For example, diverse metabolic profiles among bacterial symbionts may have been selected by dissimilarities in nutritional requirements of their different nematode hosts. Similarly, factors involved in parasitism (e.g. immune suppression and microbial competition factors), likely differ based on evolution in response to naturally encountered organisms, such as insect hosts, competitors, predators or pathogens. This study provides insight into effectors of a symbiotic lifestyle, and also highlights that when mining Xenorhabdus species for novel natural products, including antibiotics and insecticidal toxins, analysis of multiple bacterial strains likely will increase the potential for the discovery of novel molecules.
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Affiliation(s)
- Kristen E Murfin
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Amy C Whooley
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Jonathan L Klassen
- Department of Molecular & Cell Biology, University of Connecticut, Storrs, CT, 06269, USA.
| | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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29
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Chromek M. The role of the antimicrobial peptide cathelicidin in renal diseases. Pediatr Nephrol 2015; 30:1225-32. [PMID: 25159719 DOI: 10.1007/s00467-014-2895-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 06/17/2014] [Accepted: 06/23/2014] [Indexed: 12/18/2022]
Abstract
The balance between the human body and surrounding microorganisms is crucial for homeostasis and health. A disturbance in host-pathogen interactions causes disease. Two important diseases of the kidney and urinary tract are directly caused by bacteria or bacterial toxins: urinary tract infection (UTI) and diarrhea-associated hemolytic uremic syndrome (HUS). In the majority of cases, UTIs are caused by bacteria ascending from the perineum through the urethra to the urinary tract. In contrast, HUS is caused by non-invasive bacteria, such as enterohemorrhagic Escherichia coli, which colonize the gut and do not enter the blood stream. In this latter case, the bacteria release Shiga toxin, which binds to blood cells and thus reaches the target organs, mainly kidneys. Interactions between Shiga toxin, blood cells and endothelial cells in the kidney lead to cell apoptosis and inflammation. Innate immunity and the antimicrobial peptide cathelicidin seem to play important roles in the pathogenesis of both UTI and HUS. Moreover, influencing cathelicidin production and release might offer new therapeutic and prophylactic strategies for both diseases.
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Affiliation(s)
- Milan Chromek
- Paediatric Nephrology Unit, Astrid Lindgren Children's Hospital, Karolinska University Hospital Huddinge, B57, SE-14186, Stockholm, Sweden,
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30
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Murfin KE, Lee MM, Klassen JL, McDonald BR, Larget B, Forst S, Stock SP, Currie CR, Goodrich-Blair H. Xenorhabdus bovienii Strain Diversity Impacts Coevolution and Symbiotic Maintenance with Steinernema spp. Nematode Hosts. mBio 2015; 6:e00076. [PMID: 26045536 PMCID: PMC4462624 DOI: 10.1128/mbio.00076-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/08/2015] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED Microbial symbionts provide benefits that contribute to the ecology and fitness of host plants and animals. Therefore, the evolutionary success of plants and animals fundamentally depends on long-term maintenance of beneficial associations. Most work investigating coevolution and symbiotic maintenance has focused on species-level associations, and studies are lacking that assess the impact of bacterial strain diversity on symbiotic associations within a coevolutionary framework. Here, we demonstrate that fitness in mutualism varies depending on bacterial strain identity, and this is consistent with variation shaping phylogenetic patterns and maintenance through fitness benefits. Through genome sequencing of nine bacterial symbiont strains and cophylogenetic analysis, we demonstrate diversity among Xenorhabdus bovienii bacteria. Further, we identified cocladogenesis between Steinernema feltiae nematode hosts and their corresponding X. bovienii symbiont strains, indicating potential specificity within the association. To test the specificity, we performed laboratory crosses of nematode hosts with native and nonnative symbiont strains, which revealed that combinations with the native bacterial symbiont and closely related strains performed significantly better than those with more divergent symbionts. Through genomic analyses we also defined potential factors contributing to specificity between nematode hosts and bacterial symbionts. These results suggest that strain-level diversity (e.g., subspecies-level differences) in microbial symbionts can drive variation in the success of host-microbe associations, and this suggests that these differences in symbiotic success could contribute to maintenance of the symbiosis over an evolutionary time scale. IMPORTANCE Beneficial symbioses between microbes and plant or animal hosts are ubiquitous, and in these associations, microbial symbionts provide key benefits to their hosts. As such, host success is fundamentally dependent on long-term maintenance of beneficial associations. Prolonged association between partners in evolutionary time is expected to result in interactions in which only specific partners can fully support symbiosis. The contribution of bacterial strain diversity on specificity and coevolution in a beneficial symbiosis remains unclear. In this study, we demonstrate that strain-level differences in fitness benefits occur in beneficial host-microbe interactions, and this variation likely shapes phylogenetic patterns and symbiotic maintenance. This highlights that symbiont contributions to host biology can vary significantly based on very-fine-scale differences among members of a microbial species. Further, this work emphasizes the need for greater phylogenetic resolution when considering the causes and consequences of host-microbe interactions.
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Affiliation(s)
- Kristen E Murfin
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ming-Min Lee
- Department of Entomology, University of Arizona, Tucson, Arizona, USA
| | - Jonathan L Klassen
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | | | - Steven Forst
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - S Patricia Stock
- Department of Entomology, University of Arizona, Tucson, Arizona, USA
| | | | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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31
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Abstract
Bacteria that enter the bloodstream will encounter components of the cellular and soluble immune response. Platelets contribute to this response and have emerged as an important target for bacterial pathogens. Bacteria produce diverse extracellular proteins and toxins that have been reported to modulate platelet function. These interactions can result in complete or incomplete platelet activation or inhibition of platelet activation, depending on the bacteria and bacterial product. The nature of the platelet response may be highly relevant to disease pathogenesis.
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Affiliation(s)
- Oonagh Shannon
- Division of Infection Medicine, Department of Clinical Sciences, Lund University , Lund , Sweden
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32
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Iversen H, L' Abée-Lund TM, Aspholm M, Arnesen LPS, Lindbäck T. Commensal E. coli Stx2 lysogens produce high levels of phages after spontaneous prophage induction. Front Cell Infect Microbiol 2015; 5:5. [PMID: 25692100 PMCID: PMC4315091 DOI: 10.3389/fcimb.2015.00005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/12/2015] [Indexed: 12/22/2022] Open
Abstract
Enterohemorrhagic E. coli (EHEC) is a food-borne pathogen that causes disease ranging from uncomplicated diarrhea to life-threatening hemolytic uremic syndrome (HUS) and nervous system complications. Shiga toxin 2 (Stx2) is the major virulence factor of EHEC and is critical for development of HUS. The genes encoding Stx2 are carried by lambdoid bacteriophages and the toxin production is tightly linked to the production of phages during lytic cycle. It has previously been suggested that commensal E. coli could amplify the production of Stx2-phages and contribute to the severity of disease. In this study we examined the susceptibility of commensal E. coli strains to the Stx2-converting phage ϕ734, isolated from a highly virulent EHEC O103:H25 (NIPH-11060424). Among 38 commensal E. coli strains from healthy children below 5 years, 15 were lysogenized by the ϕ734 phage, whereas lytic infection was not observed. Three of the commensal E. coli ϕ734 lysogens were tested for stability, and appeared stable and retained the phage for at least 10 cultural passages. When induced to enter lytic cycle by H2O2 treatment, 8 out of 13 commensal lysogens produced more ϕ734 phages than NIPH-11060424. Strikingly, five of them even spontaneously (non-induced) produced higher levels of phage than the H2O2 induced NIPH-11060424. An especially high frequency of HUS (60%) was seen among children infected by NIPH-11060424 during the outbreak in 2006. Based on our findings, a high Stx2 production by commensal E. coli lysogens cannot be ruled out as a contributor to the high frequency of HUS during this outbreak.
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Affiliation(s)
- Hildegunn Iversen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences Oslo, Norway
| | - Trine M L' Abée-Lund
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences Oslo, Norway
| | - Marina Aspholm
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences Oslo, Norway
| | - Lotte P S Arnesen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences Oslo, Norway
| | - Toril Lindbäck
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences Oslo, Norway
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33
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Effects of Shiga toxin type 2 on a bioengineered three-dimensional model of human renal tissue. Infect Immun 2014; 83:28-38. [PMID: 25312954 DOI: 10.1128/iai.02143-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxins (Stx) are a family of cytotoxic proteins that can cause hemolytic-uremic syndrome (HUS), a thrombotic microangiopathy, following infections by Shiga toxin-producing Escherichia coli (STEC). Renal failure is a key feature of HUS and a major cause of childhood renal failure worldwide. There are currently no specific therapies for STEC-associated HUS, and the mechanism of Stx-induced renal injury is not well understood primarily due to a lack of fully representative animal models and an inability to monitor disease progression on a molecular or cellular level in humans at early stages. Three-dimensional (3D) tissue models have been shown to be more in vivo-like in their phenotype and physiology than 2D cultures for numerous disease models, including cancer and polycystic kidney disease. It is unknown whether exposure of a 3D renal tissue model to Stx will yield a more in vivo-like response than 2D cell culture. In this study, we characterized Stx2-mediated cytotoxicity in a bioengineered 3D human renal tissue model previously shown to be a predictor of drug-induced nephrotoxicity and compared its response to Stx2 exposure in 2D cell culture. Our results demonstrate that although many mechanistic aspects of cytotoxicity were similar between 3D and 2D, treatment of the 3D tissues with Stx resulted in an elevated secretion of the kidney injury marker 1 (Kim-1) and the cytokine interleukin-8 compared to the 2D cell cultures. This study represents the first application of 3D tissues for the study of Stx-mediated kidney injury.
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34
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Gomez SA, Abrey-Recalde MJ, Panek CA, Ferrarotti NF, Repetto MG, Mejías MP, Fernández GC, Vanzulli S, Isturiz MA, Palermo MS. The oxidative stress induced in vivo by Shiga toxin-2 contributes to the pathogenicity of haemolytic uraemic syndrome. Clin Exp Immunol 2013; 173:463-72. [PMID: 23607458 DOI: 10.1111/cei.12124] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2013] [Indexed: 12/19/2022] Open
Abstract
Typical haemolytic uraemic syndrome (HUS) is caused by Shiga toxin (Stx)-producing Escherichia coli infections and is characterized by thrombotic microangiopathy that leads to haemolytic anaemia, thrombocytopenia and acute renal failure. Renal or neurological sequelae are consequences of irreversible tissue damage during the acute phase. Stx toxicity and the acute inflammatory response raised by the host determine the development of HUS. At present there is no specific therapy to control Stx damage. The pathogenic role of reactive oxygen species (ROS) on endothelial injury has been largely documented. In this study, we investigated the in-vivo effects of Stx on the oxidative balance and its contribution to the development of HUS in mice. In addition, we analysed the effect of anti-oxidant agents as therapeutic tools to counteract Stx toxicity. We demonstrated that Stx induced an oxidative imbalance, evidenced by renal glutathione depletion and increased lipid membrane peroxidation. The increased ROS production by neutrophils may be one of the major sources of oxidative stress during Stx intoxication. All these parameters were ameliorated by anti-oxidants reducing platelet activation, renal damage and increasing survival. To conclude, Stx generates a pro-oxidative state that contributes to kidney failure, and exogenous anti-oxidants could be beneficial to counteract this pathogenic pathway.
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Affiliation(s)
- S A Gomez
- Servicio de Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas, ANLIS 'Dr Carlos G. Malbrán', Buenos Aires, Argentina
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35
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Amaral MM, Sacerdoti F, Jancic C, Repetto HA, Paton AW, Paton JC, Ibarra C. Action of shiga toxin type-2 and subtilase cytotoxin on human microvascular endothelial cells. PLoS One 2013; 8:e70431. [PMID: 23936204 PMCID: PMC3728274 DOI: 10.1371/journal.pone.0070431] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 06/18/2013] [Indexed: 01/29/2023] Open
Abstract
The hemolytic uremic syndrome (HUS) associated with diarrhea is a complication of Shiga toxin (Stx)-producing Escherichia coli (STEC) infection. In Argentina, HUS is endemic and responsible for acute and chronic renal failure in children younger than 5 years old. The human kidney is the most affected organ due to the presence of very Stx-sensitive cells, such as microvascular endothelial cells. Recently, Subtilase cytotoxin (SubAB) was proposed as a new toxin that may contribute to HUS pathogenesis, although its action on human glomerular endothelial cells (HGEC) has not been described yet. In this study, we compared the effects of SubAB with those caused by Stx2 on primary cultures of HGEC isolated from fragments of human pediatric renal cortex. HGEC were characterized as endothelial since they expressed von Willebrand factor (VWF) and platelet/endothelial cell adhesion molecule 1 (PECAM-1). HGEC also expressed the globotriaosylceramide (Gb3) receptor for Stx2. Both, Stx2 and SubAB induced swelling and detachment of HGEC and the consequent decrease in cell viability in a time-dependent manner. Preincubation of HGEC with C-9 −a competitive inhibitor of Gb3 synthesis-protected HGEC from Stx2 but not from SubAB cytotoxic effects. Stx2 increased apoptosis in a time-dependent manner while SubAB increased apoptosis at 4 and 6 h but decreased at 24 h. The apoptosis induced by SubAB relative to Stx2 was higher at 4 and 6 h, but lower at 24 h. Furthermore, necrosis caused by Stx2 was significantly higher than that induced by SubAB at all the time points evaluated. Our data provide evidence for the first time how SubAB could cooperate with the development of endothelial damage characteristic of HUS pathogenesis.
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Affiliation(s)
- María M Amaral
- Laboratorio de Fisiopatogenia, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
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36
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Karpman D, Tati R. Complement activation in thrombotic microangiopathy. Hamostaseologie 2013; 33:96-104. [PMID: 23411690 DOI: 10.5482/hamo-12-12-0025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 01/23/2013] [Indexed: 01/01/2023] Open
Abstract
The endothelium lining the vascular lumen is continuously exposed to complement from the circulation. When erroneously activated on host cells, complement may generate a deleterious effect on the vascular wall leading to endothelial injury, exposure of the subendothelial matrix and platelet activation. In this review the contribution of complement activation to formation and maintenance of the pathological lesion termed thrombotic microangiopathy (TMA) is discussed. TMA is defined by vessel wall thickening affecting mainly arterioles and capillaries, detachment of the endothelial cell from the basement membrane and intraluminal thrombosis resulting in occlusion of the vessel lumen. The TMA lesion occurs in haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). HUS is further sub-classified as associated with Shiga toxin-producing Escherichia coli (STEC-HUS) or with complement dysregulation (atypical HUS) as well as other less common forms. The contribution of dysregulated complement activation to endothelial injury and platelet aggregation is reviewed as well as specific complement involvement in the development of HUS and TTP.
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Affiliation(s)
- D Karpman
- Department of Paediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden.
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37
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Lauridsen LH, Veedu RN. Nucleic acid aptamers against biotoxins: a new paradigm toward the treatment and diagnostic approach. Nucleic Acid Ther 2012; 22:371-9. [PMID: 23113767 DOI: 10.1089/nat.2012.0377] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides that can bind to their targets with very high affinity and specificity, and are generally selected by a process referred to as systematic evolution of ligands by exponential enrichment. Conventional antibody-based therapeutic and diagnostic approach currently employed against biotoxins pose major limitations such as the requirement of a live animal for the in vivo enrichment of the antibody species, decreased stability, high production cost, and side effects. Aptamer technology is a viable alternative that can be used to combat these problems. Fully sequestered in vitro, aptamers eliminate the need for a living host. Furthermore, one of the key advantages of using aptamers instead of antibodies is that they can be selected against very weakly immunogenic and cytotoxic substances. In this review, we focus on nucleic acid aptamers developed against various biotoxins of plant, microorganism, or animal origin and show how these can be used in diagnostics (e.g., biosensors) and therapy.
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Affiliation(s)
- Lasse Holm Lauridsen
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
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38
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Chromek M, Arvidsson I, Karpman D. The antimicrobial peptide cathelicidin protects mice from Escherichia coli O157:H7-mediated disease. PLoS One 2012; 7:e46476. [PMID: 23077510 PMCID: PMC3471911 DOI: 10.1371/journal.pone.0046476] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 08/30/2012] [Indexed: 12/16/2022] Open
Abstract
This study investigated the role of the antimicrobial peptide cathelicidin in Escherichia coli O157:H7 infection and subsequent renal damage. Mouse and human cathelicidin, CRAMP and LL-37, respectively, killed E. coli O157:H7 in vitro. Intestines from healthy wild-type (129/SvJ) and cathelicidin-knock-out (Camp−/−) mice were investigated, showing that cathelicidin-deficient mice had a thinner colonic mucus layer compared with wild-type mice. Wild-type (n = 11) and cathelicidin-knock-out (n = 11) mice were inoculated with E. coli O157:H7. Cathelicidin-deficient animals exhibited higher fecal counts of E. coli O157:H7 and bacteria penetrated the mucus forming attaching-and-effacing lesions to a much higher extent than in wild-type animals. Cathelicidin knock-out mice developed symptoms (9/11) as well as anemia, thrombocytopenia and extensive renal tubular damage while all cathelicidin-producing mice remained asymptomatic with normal laboratory findings. When injected with Shiga toxin intraperitoneally, both murine strains developed the same degree of renal tubular damage and clinical disease indicating that differences in sensitivity to infection between the murine strains were related to the initial intestinal response. In conclusion, cathelicidin substantially influenced the antimicrobial barrier in the mouse colon mucosa. Cathelicidin deficiency lead to increased susceptibility to E. coli O157:H7 infection and subsequent renal damage. Administration of cathelicidin or stimulation of endogenous production may prove to be novel treatments for E. coli O157:H7-induced hemolytic uremic syndrome.
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Affiliation(s)
| | | | - Diana Karpman
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
- * E-mail:
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