Cognitive deficits found in a pro-inflammatory state are independent of ERK 1/2 signaling in the murine brain hippocampus treated with Shiga toxin 2 from enterohemorrhagic Escherichia Coli

AbstractShiga toxin 2 (Stx2) from enterohemorrhagic Escherichia coli (EHEC) produces hemorrhagic colitis, hemolytic uremic syndrome (HUS) and acute encephalopathy. The mortality rate in HUS increases significantly when the central nervous system (CNS) is involved. Besides, EHEC also releases lipopolysaccharide (LPS). Many reports have described cognitive dysfunctions in HUS patients, the hippocampus being one of the brain areas targeted by EHEC infection. In this context, a translational murine model of encephalopathy was employed to establish the deleterious effects of Stx2 and the contribution of LPS in the hippocampus. Results demonstrate that systemic administration of a sublethal dose of Stx2 reduced memory index and produced depression like behavior, pro-inflammatory cytokine release and NF-kB activation independent of the ERK 1/2 signaling pathway. On the other hand, LPS activated NF-kB dependent on ERK 1/2 signaling pathway. Cotreatment of Stx2 with LPS aggravated the pathologic state, while dexamethasone treatment succeeded in preventing behavioral alterations. Our present work suggests that the use of drugs such as corticosteroids or NF-kB signaling inhibitors may serve as neuroprotectors from EHEC infection.Author SummaryShiga toxin (Stx) from enterohemorrhagic Escherichia coli (EHEC) is one of the most virulent factors responsible for hemolytic uremic syndrome (HUS). Stx2, the endemic variant targets the brain, among other organs, thus inducing encephalopathies. Central nervous system (CNS) compromise was the main predictor of death in patients with HUS. Stx2 may exert a direct action in the CNS, by disrupting the neurovascular unit. In this context, we investigate the molecular signaling triggered by Stx2 in the murine brain hippocampus involved in inflammatory mechanisms that altered hippocampal-related cognitive behaviors. The present data underscore that the use of drugs such as dexamethasone or those blocking the cascade by preventing NF-kB translocation to the nucleus may serve as effective neuroprotectors with potentially beneficial use in the clinic.

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Promoter Sequence of Shiga Toxin 2 (Stx2) Is Recognized In Vivo, Leading to Production of Biologically Active Stx2

mBio ◽

10.1128/mbio.00501-13 ◽

2013 ◽

Vol 4 (5) ◽

Cited By ~ 11

Author(s):

Leticia V. Bentancor ◽

Maria P. Mejías ◽

Alípio Pinto ◽

Marcos F. Bilen ◽

Roberto Meiss ◽

...

Keyword(s):

Escherichia Coli ◽

Central Nervous System ◽

Nervous System ◽

Hemolytic Uremic Syndrome ◽

Shiga Toxin ◽

Biologically Active ◽

Eukaryotic Cells ◽

Content Type ◽

Uremic Syndrome

ABSTRACTShiga toxins (Stx) are the main agent responsible for the development of hemolytic-uremic syndrome (HUS), the most severe and life-threatening systemic complication of infection with enterohemorrhagicEscherichia coli(EHEC) strains. We previously described Stx2 expression by eukaryotic cells after they were transfectedin vitrowith thestx2gene cloned into a prokaryotic plasmid (pStx2). The aim of this study was to evaluate whether mammalian cells were also able to express Stx2in vivoafter pStx2 injection. Mice were inoculated by hydrodynamics-based transfection (HBT) with pStx2. We studied the survival, percentage of polymorphonuclear leukocytes in plasma, plasma urea levels, and histology of the kidneys and the brains of mice. Mice displayed a lethal dose-related response to pStx2. Stx2 mRNA was recovered from the liver, and Stx2 cytotoxic activity was observed in plasma of mice injected with pStx2. Stx2 was detected by immunofluorescence in the brains of mice inoculated with pStx2, and markers of central nervous system (CNS) damage were observed, including increased expression of glial fibrillary acidic protein (GFAP) and fragmentation of NeuN in neurons. Moreover, anti-Stx2B-immunized mice were protected against pStx2 inoculation. Our results show that Stx2 is expressedin vivofrom the wildstx2gene, reproducing pathogenic damage induced by purified Stx2 or secondary to EHEC infection.IMPORTANCEEnterohemorrhagic Shiga toxin (Stx)-producingEscherichia coli(EHEC) infections are a serious public health problem, and Stx is the main pathogenic agent associated with typical hemolytic-uremic syndrome (HUS). In contrast to the detailed information describing the molecular basis for EHEC adherence to epithelial cells, very little is known about how Stx is released from bacteria in the gut, reaching its target tissues, mainly the kidney and central nervous system (CNS). In order to develop an efficient treatment for EHEC infections, it is necessary to understand the mechanisms involved in Stx expression. In this regard, the present study demonstrates that mammals can synthesize biologically active Stx using the natural promoter associated with the Stx-converting bacteriophage genome. These results could impact the comprehension of EHEC HUS, since local eukaryotic cells transduced and/or infected by bacteriophage encoding Stx2 could be an alternative source of Stx production.

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Steroid Pulse Therapy for Severe Central Nervous System Involvement in Shiga Toxin-Producing Escherichia coli-Related Hemolytic Uremic Syndrome

Case Reports in Pediatrics ◽

10.1155/2021/5587050 ◽

2021 ◽

Vol 2021 ◽

pp. 1-4

Author(s):

Chiara Rosazza ◽

Alberto M Cappellari ◽

Cristiano Gandini ◽

Elisa Scola ◽

Gianluigi Ardissino

Keyword(s):

Escherichia Coli ◽

Central Nervous System ◽

Nervous System ◽

Hemolytic Uremic Syndrome ◽

Shiga Toxin ◽

Pulse Therapy ◽

Steroid Pulse Therapy ◽

High Dose ◽

Steroid Pulse ◽

Uremic Syndrome

We report on the case of a 7-year-old boy with Shiga toxin-producing Escherichia coli-related hemolytic uremic syndrome (STEC-HUS), initially presenting with abdominal pain as the only clinical feature and thus requiring differential diagnosis with a surgical emergency. Diagnosis of STEC-HUS was made with the appearance of bloody diarrhea and renal function impairment, and the clinical picture rapidly progressed to multiorgan failure. Relatively late and severe central nervous system (CNS) involvement was present, characterized by subacute encephalitis progressing to coma, which became apparent when the acute phase of thrombotic microangiopathy was resolving. Therefore, neurologic manifestations were thought to be related to reperfusion damage to the CNS and high-dose IV steroid pulse therapy was empirically administered. Following this therapeutic scheme, neurologic involvement resolved with no sequelae. This case offers several points of discussion on the clinical presentation and the diagnostic approach to STEC-HUS, on the related neurologic complications, and on a novel approach to their management.

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Genomic Comparison of Two O111:H−Enterohemorrhagic Escherichia coli Isolates from a Historic Hemolytic-Uremic Syndrome Outbreak in Australia

Infection and Immunity ◽

10.1128/iai.01229-15 ◽

2016 ◽

Vol 84 (3) ◽

pp. 775-781 ◽

Cited By ~ 10

Author(s):

Lauren J. McAllister ◽

Stephen J. Bent ◽

Nicola K. Petty ◽

Elizabeth Skippington ◽

Scott A. Beatson ◽

...

Keyword(s):

Escherichia Coli ◽

Hemolytic Uremic Syndrome ◽

Sequence Data ◽

Enterohemorrhagic Escherichia Coli ◽

Nucleotide Polymorphisms ◽

Extra Copy ◽

Content Type ◽

Shiga Toxin 2 ◽

Uremic Syndrome ◽

Insertion Sites

EnterohemorrhagicEscherichia coli(EHEC) is an important cause of diarrhea and hemolytic-uremic syndrome (HUS) worldwide. Australia's worst outbreak of HUS occurred in Adelaide in 1995 and was one of the first major HUS outbreaks attributed to a non-O157 Shiga-toxigenicE. coli(STEC) strain. Molecular analyses conducted at the time suggested that the outbreak was caused by an O111:H−clone, with strains from later in the outbreak harboring an extra copy of the genes encoding the potent Shiga toxin 2 (Stx2). Two decades later, we have used next-generation sequencing to compare two isolates from early and late in this important outbreak. We analyzed genetic content, single-nucleotide polymorphisms (SNPs), and prophage insertion sites; for the latter, we demonstrate how paired-end sequence data can be leveraged to identify such insertion sites. The two strains are genetically identical except for six SNP differences and the presence of not one but two additional Stx2-converting prophages in the later isolate. Isolates from later in the outbreak were associated with higher levels of morbidity, suggesting that the presence of the additional Stx2-converting prophages is significant in terms of the virulence of this clone.

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Gut–Kidney Axis on Chip for Studying Effects of Antibiotics on Risk of Hemolytic Uremic Syndrome by Shiga Toxin-Producing Escherichia coli

Toxins ◽

10.3390/toxins13110775 ◽

2021 ◽

Vol 13 (11) ◽

pp. 775

Author(s):

Yugyeong Lee ◽

Min-Hyeok Kim ◽

David Rodrigues Alves ◽

Sejoong Kim ◽

Luke P. Lee ◽

...

Keyword(s):

Escherichia Coli ◽

Hemolytic Uremic Syndrome ◽

Shiga Toxin ◽

Low Frequency ◽

Kidney Cells ◽

Number Of Patients ◽

Relevant Situation ◽

Shiga Toxin 2 ◽

Uremic Syndrome ◽

On Chip

Shiga toxin-producing Escherichia coli (STEC) infects humans by colonizing the large intestine, and causes kidney damage by secreting Shiga toxins (Stxs). The increased secretion of Shiga toxin 2 (Stx2) by some antibiotics, such as ciprofloxacin (CIP), increases the risk of hemolytic–uremic syndrome (HUS), which can be life-threatening. However, previous studies evaluating this relationship have been conflicting, owing to the low frequency of EHEC infection, very small number of patients, and lack of an appropriate animal model. In this study, we developed gut–kidney axis (GKA) on chip for co-culturing gut (Caco-2) and kidney (HKC-8) cells, and observed both STEC O157:H7 (O157) infection and Stx intoxication in the gut and kidney cells on the chip, respectively. Without any antibiotic treatment, O157 killed both gut and kidney cells in GKA on the chip. CIP treatment reduced O157 infection in the gut cells, but increased Stx2-induced damage in the kidney cells, whereas the gentamycin treatment reduced both O157 infection in the gut cells and Stx2-induced damage in the kidney cells. This is the first report to recapitulate a clinically relevant situation, i.e., that CIP treatment causes more damage than gentamicin treatment. These results suggest that GKA on chip is very useful for simultaneous observation of O157 infections and Stx2 poisoning in gut and kidney cells, making it suitable for studying the effects of antibiotics on the risk of HUS.

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Involvement of NF-κB1 and the Non-Canonical NF-κB Signaling Pathway in the Pathogenesis of Acute Kidney Injury in Shiga-Toxin-2-Induced Hemolytic-Uremic Syndrome in Mice

Shock ◽

10.1097/shk.0000000000001558 ◽

2020 ◽

Vol Publish Ahead of Print ◽

Author(s):

Isabelle V. Sobbe ◽

Nadine Krieg ◽

Sophie Dennhardt ◽

Sina M. Coldewey

Keyword(s):

Acute Kidney Injury ◽

Hemolytic Uremic Syndrome ◽

Signaling Pathway ◽

Shiga Toxin ◽

Kidney Injury ◽

Shiga Toxin 2 ◽

Uremic Syndrome

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Human Microbiota-Secreted Factors Inhibit Shiga Toxin Synthesis by Enterohemorrhagic Escherichia coli O157:H7

Infection and Immunity ◽

10.1128/iai.01048-08 ◽

2008 ◽

Vol 77 (2) ◽

pp. 783-790 ◽

Cited By ~ 74

Author(s):

Thibaut de Sablet ◽

Christophe Chassard ◽

Annick Bernalier-Donadille ◽

Marjolaine Vareille ◽

Alain P. Gobert ◽

...

Keyword(s):

Escherichia Coli ◽

Virulence Factor ◽

Shiga Toxin ◽

Enterohemorrhagic Escherichia Coli ◽

Lytic Cycle ◽

E Coli ◽

Human Microbiota ◽

Shiga Toxin 2 ◽

Uremic Syndrome ◽

Serious Disease

ABSTRACT Escherichia coli O157:H7 is a food-borne pathogen causing hemorrhagic colitis and hemolytic-uremic syndrome, especially in children. The main virulence factor responsible for the more serious disease is the Shiga toxin 2 (Stx2), which is released in the gut after oral ingestion of the organism. Although it is accepted that the amount of Stx2 produced by E. coli O157:H7 in the gut is critical for the development of disease, the eukaryotic or prokaryotic gut factors that modulate Stx2 synthesis are largely unknown. In this study, we examined the influence of prokaryotic molecules released by a complex human microbiota on Stx2 synthesis by E. coli O157:H7. Stx2 synthesis was assessed after growth of E. coli O157:H7 in cecal contents of gnotobiotic rats colonized with human microbiota or in conditioned medium having supported the growth of complex human microbiota. Extracellular prokaryotic molecules produced by the commensal microbiota repress stx 2 mRNA expression and Stx2 production by inhibiting the spontaneous and induced lytic cycle mediated by RecA. These molecules, with a molecular mass of below 3 kDa, are produced in part by Bacteroides thetaiotaomicron, a predominant species of the normal human intestinal microbiota. The microbiota-induced stx 2 repression is independent of the known quorum-sensing pathways described in E. coli O157:H7 involving SdiA, QseA, QseC, or autoinducer 3. Our findings demonstrate for the first time the regulatory activity of a soluble factor produced by the complex human digestive microbiota on a bacterial virulence factor in a physiologically relevant context.

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Isolation of an Escherichia coli O157:H7 strain producing Shiga toxin 1 but not Shiga toxin 2 from a patient with hemolytic uremic syndrome in Korea

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.1998.tb13181.x ◽

1998 ◽

Vol 166 (1) ◽

pp. 43-48 ◽

Cited By ~ 13

Author(s):

Yung Bu Kim ◽

Jun Okuda ◽

Chiho Matsumoto ◽

Tadaaki Morigaki ◽

Norio Asai ◽

...

Keyword(s):

Escherichia Coli ◽

Hemolytic Uremic Syndrome ◽

Shiga Toxin ◽

Escherichia Coli O157 ◽

Shiga Toxin 2 ◽

Uremic Syndrome

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Therapeutic Strategies to Protect the Central Nervous System against Shiga Toxin from Enterohemorrhagic Escherichia coli

Current Neuropharmacology ◽

10.2174/1570159x18666200220143001 ◽

2020 ◽

Vol 19 (1) ◽

pp. 24-44 ◽

Cited By ~ 1

Author(s):

Jorge Goldstein ◽

Krista Nuñez-Goluboay ◽

Alipio Pinto

Keyword(s):

Escherichia Coli ◽

Central Nervous System ◽

Nervous System ◽

Shiga Toxin ◽

Inflammatory Responses ◽

Clinical Signs ◽

Enterohemorrhagic Escherichia Coli ◽

Cns Injury ◽

Immune System Activation ◽

The Central Nervous System

: Infection with Shiga toxin-producing Escherichia coli (STEC) may cause hemorrhagic colitis, hemolytic uremic syndrome (HUS) and encephalopathy. The mortality rate derived from HUS adds up to 5% of the cases, and up to 40% when the central nervous system (CNS) is involved. In addition to the well-known deleterious effect of Stx, the gram-negative STEC releases lipopolysaccharides (LPS) and may induce a variety of inflammatory responses when released in the gut. Common clinical signs of severe CNS injury include sensorimotor, cognitive, emotional and/or autonomic alterations. In the last few years, a number of drugs have been experimentally employed to establish the pathogenesis of, prevent or treat CNS injury by STEC. The strategies in these approaches focus on: 1) inhibition of Stx production and release by STEC, 2) inhibition of Stx bloodstream transport, 3) inhibition of Stx entry into the CNS parenchyma, 4) blockade of deleterious Stx action in neural cells, and 5) inhibition of immune system activation and CNS inflammation. Fast diagnosis of STEC infection, as well as the establishment of early CNS biomarkers of damage, may be determinants of adequate neuropharmacological treatment in time.

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Complement activation on platelet-leukocyte complexes and microparticles in enterohemorrhagic Escherichia coli–induced hemolytic uremic syndrome

Blood ◽

10.1182/blood-2010-09-309161 ◽

2011 ◽

Vol 117 (20) ◽

pp. 5503-5513 ◽

Cited By ~ 118

Author(s):

Anne-lie Ståhl ◽

Lisa Sartz ◽

Diana Karpman

Keyword(s):

Escherichia Coli ◽

Hemolytic Uremic Syndrome ◽

Shiga Toxin ◽

Complement Activation ◽

Whole Blood ◽

Enterohemorrhagic Escherichia Coli ◽

Escherichia Coli O157 ◽

Plasma Samples ◽

Uremic Syndrome ◽

Platelet Microparticles

AbstractHemolytic uremic syndrome (HUS) is commonly associated with Shiga toxin (Stx)–producing Escherichia coli O157:H7 infection. This study examined patient samples for complement activation on leukocyte-platelet complexes and microparticles, as well as donor samples for Stx and lipopolysaccharide (O157LPS)–induced complement activation on platelet-leukocyte complexes and microparticles. Results, analyzed by flow cytometry, showed that whole blood from a child with HUS had surface-bound C3 on 30% of platelet-monocyte complexes compared with 14% after recovery and 12% in pediatric controls. Plasma samples from 12 HUS patients were analyzed for the presence of microparticles derived from platelets, monocytes, and neutrophils. Acute-phase samples exhibited high levels of platelet microparticles and, to a lesser extent, monocyte microparticles, both bearing C3 and C9. Levels decreased significantly at recovery. Stx or O157LPS incubated with donor whole blood increased the population of platelet-monocyte and platelet-neutrophil complexes with surface-bound C3 and C9, an effect enhanced by costimulation with Stx and O157LPS. Both Stx and O157LPS induced the release of C3- and C9-bearing microparticles from platelets and monocytes. Released microparticles were phagocytosed by neutrophils. The presence of complement on platelet-leukocyte complexes and microparticles derived from these cells suggests a role in the inflammatory and thrombogenic events that occur during HUS.

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