|
1
|
Varrone E, Carnicelli D, He X, Grasse M, Stampfer K, Huber S, Kellnerová S, Tazzari PL, Ricci F, Paterini P, Ardissino G, Morabito S, Orth-Höller D, Würzner R, Brigotti M. Detection of Cleaved Stx2a in the Blood of STEC-Infected Patients. Toxins (Basel) 2023; 15:690. [PMID: 38133194 PMCID: PMC10747961 DOI: 10.3390/toxins15120690] [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: 10/31/2023] [Revised: 11/24/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023] Open
Abstract
Typical hemolytic uremic syndrome (HUS) is mainly caused by Shiga toxin-producing Escherichia coli (STEC) releasing Shiga toxin 2 (Stx2). Two different structures of this AB5 toxin have been described: uncleaved, with intact B and A chains, and cleaved, with intact B and a nicked A chain consisting of two fragments, A1 and A2, connected by a disulfide bond. Despite having the same toxic effect on sensitive cells, the two forms differ in their binding properties for circulating cells, serum components and complement factors, thus contributing to the pathogenesis of HUS differently. The outcome of STEC infections and the development of HUS could be influenced by the relative amounts of uncleaved or cleaved Stx2 circulating in patients' blood. Cleaved Stx2 was identified and quantified for the first time in four out of eight STEC-infected patients' sera by a method based on the inhibition of cell-free translation. Cleaved Stx2 was present in the sera of patients with toxins bound to neutrophils and in two out of three patients developing HUS, suggesting its involvement in HUS pathogenesis, although in association with other bacterial or host factors.
Collapse
Affiliation(s)
- Elisa Varrone
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (E.V.); (D.C.); (P.P.)
| | - Domenica Carnicelli
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (E.V.); (D.C.); (P.P.)
| | - Xiaohua He
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA;
| | - Marco Grasse
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.G.); (K.S.); (S.H.); (S.K.); (R.W.)
| | - Karin Stampfer
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.G.); (K.S.); (S.H.); (S.K.); (R.W.)
| | - Silke Huber
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.G.); (K.S.); (S.H.); (S.K.); (R.W.)
| | - Sára Kellnerová
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.G.); (K.S.); (S.H.); (S.K.); (R.W.)
| | - Pier Luigi Tazzari
- Immunohematology and Transfusion Center, S. Orsola-Malpighi Hospital, Via Massarenti 9, 40138 Bologna, Italy; (P.L.T.); (F.R.)
| | - Francesca Ricci
- Immunohematology and Transfusion Center, S. Orsola-Malpighi Hospital, Via Massarenti 9, 40138 Bologna, Italy; (P.L.T.); (F.R.)
| | - Paola Paterini
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (E.V.); (D.C.); (P.P.)
- Center for Applied Biomedical Research-CRBA, University of Bologna, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy
| | - Gianluigi Ardissino
- Center for HUS Control, Prevention and Management, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Commenda 9, 20122 Milano, Italy;
| | - Stefano Morabito
- European Reference Laboratory for Escherichia coli, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | | | - Reinhard Würzner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.G.); (K.S.); (S.H.); (S.K.); (R.W.)
| | - Maurizio Brigotti
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (E.V.); (D.C.); (P.P.)
| |
Collapse
|
|
2
|
Kellnerová S, Huber S, Massri M, Fleischer V, Losso K, Sarg B, Kremser L, Talasz H, He X, Varrone E, Brigotti M, Ardissino G, Orth-Höller D, Würzner R. Enzymatic Cleavage of Stx2a in the Gut and Identification of Pancreatic Elastase and Trypsin as Possible Main Cleavers. Microorganisms 2023; 11:2487. [PMID: 37894145 PMCID: PMC10609011 DOI: 10.3390/microorganisms11102487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/15/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023] Open
Abstract
Shiga toxins (Stxs), especially the Stx2a subtype, are the major virulence factors involved in enterohemorrhagic Escherichia coli (EHEC)-associated hemolytic uremic syndrome (eHUS), a life-threatening disease causing acute kidney injury, especially in children. After oral transmission and colonization in the gut, EHEC release Stx. Intracellular cleavage of the Stx A subunit, when followed by reduction, boosts the enzymatic activity that causes damage to targeted cells. This cleavage was assumed to be mostly mediated by furin during Stx intracellular trafficking. To investigate whether this cleavage could occur in the intestine, even prior to entering target cells, Stx2a A subunit structure (intact or cleaved) was characterized after its exposure to specific host factors present in human stool. The molecular weight of Stx2a A subunit/fragments was determined by immunoblotting after electrophoretic separation under reducing conditions. In this study, it was demonstrated that Stx2a is cleaved by certain human stool components. Trypsin and chymotrypsin-like elastase 3B (CELA3B), two serine proteases, were identified as potential candidates that can trigger the extracellular cleavage of Stx2a A subunit directly after its secretion by EHEC in the gut. Whether the observed cleavage indeed translates to natural infections and plays a role in eHUS pathogenesis has yet to be determined. If so, it seems likely that a host's protease profile could affect disease development by changing the toxin's biological features.
Collapse
Affiliation(s)
- Sára Kellnerová
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Silke Huber
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Mariam Massri
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Verena Fleischer
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| | - Klemens Losso
- Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, 6020 Innsbruck, Austria;
- Department of Food Technology and Nutrition, MCI|The Entrepreneurial School, 6020 Innsbruck, Austria
| | - Bettina Sarg
- Protein Core Facility, Institute of Medical Biochemistry, Center of Chemistry and Biomedicine, Medical University of Innsbruck, 6020 Innsbruck, Austria; (B.S.); (L.K.); (H.T.)
| | - Leopold Kremser
- Protein Core Facility, Institute of Medical Biochemistry, Center of Chemistry and Biomedicine, Medical University of Innsbruck, 6020 Innsbruck, Austria; (B.S.); (L.K.); (H.T.)
| | - Heribert Talasz
- Protein Core Facility, Institute of Medical Biochemistry, Center of Chemistry and Biomedicine, Medical University of Innsbruck, 6020 Innsbruck, Austria; (B.S.); (L.K.); (H.T.)
| | - Xiaohua He
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, Albany, CA 74710, USA;
| | - Elisa Varrone
- Department of Medical and Surgical Sciences, School of Medicine, University of Bologna, 40126 Bologna, Italy; (E.V.); (M.B.)
| | - Maurizio Brigotti
- Department of Medical and Surgical Sciences, School of Medicine, University of Bologna, 40126 Bologna, Italy; (E.V.); (M.B.)
| | - Gianluigi Ardissino
- Center for HUS Prevention, Control and Management at Pediatric Nephrology, Dialysis and Transplant Unit, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy;
| | - Dorothea Orth-Höller
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
- MB-LAB–Clinical Microbiology Laboratory, 6020 Innsbruck, Austria
| | - Reinhard Würzner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.K.); (S.H.); (M.M.); (V.F.)
| |
Collapse
|
|
3
|
Buelli S, Locatelli M, Carminati CE, Corna D, Cerullo D, Imberti B, Perico L, Brigotti M, Abbate M, Zoja C, Benigni A, Remuzzi G, Morigi M. Shiga Toxin 2 Triggers C3a-Dependent Glomerular and Tubular Injury through Mitochondrial Dysfunction in Hemolytic Uremic Syndrome. Cells 2022; 11:cells11111755. [PMID: 35681450 PMCID: PMC9179250 DOI: 10.3390/cells11111755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/13/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli is the predominant offending agent of post-diarrheal hemolytic uremic syndrome (HUS), a rare disorder of microvascular thrombosis and acute kidney injury possibly leading to long-term renal sequelae. We previously showed that C3a has a critical role in the development of glomerular damage in experimental HUS. Based on the evidence that activation of C3a/C3a receptor (C3aR) signaling induces mitochondrial dysregulation and cell injury, here we investigated whether C3a caused podocyte and tubular injury through induction of mitochondrial dysfunction in a mouse model of HUS. Mice coinjected with Stx2/LPS exhibited glomerular podocyte and tubular C3 deposits and C3aR overexpression associated with cell damage, which were limited by C3aR antagonist treatment. C3a promoted renal injury by affecting mitochondrial wellness as demonstrated by data showing that C3aR blockade reduced mitochondrial ultrastructural abnormalities and preserved mitochondrial mass and energy production. In cultured podocytes and tubular cells, C3a caused altered mitochondrial fragmentation and distribution, and reduced anti-oxidant SOD2 activity. Stx2 potentiated the responsiveness of renal cells to the detrimental effects of C3a through increased C3aR protein expression. These results indicate that C3aR may represent a novel target in Stx-associated HUS for the preservation of renal cell integrity through the maintenance of mitochondrial function.
Collapse
Affiliation(s)
- Simona Buelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
- Correspondence: ; Tel.: +39-035-42131; Fax: +39-035-319-331
| | - Monica Locatelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Claudia Elisa Carminati
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Daniela Corna
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Domenico Cerullo
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Barbara Imberti
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Luca Perico
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Maurizio Brigotti
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40126 Bologna, Italy;
| | - Mauro Abbate
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Carlamaria Zoja
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Ariela Benigni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Marina Morigi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| |
Collapse
|
|
4
|
Rippa M, Sagnelli D, Vestri A, Marchesano V, Munari B, Carnicelli D, Varrone E, Brigotti M, Tozzoli R, Montalbano M, Morabito S, Zhou J, Zyss J, Petti L. Plasmonic Metasurfaces for Specific SERS Detection of Shiga Toxins. ACS APPLIED MATERIALS & INTERFACES 2022; 14:4969-4979. [PMID: 35044743 PMCID: PMC8815041 DOI: 10.1021/acsami.1c21553] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The interest in the development of nanoscale plasmonic technologies has dramatically increased in recent years. The photonic properties of plasmonic nanopatterns can be controlled and tuned via their size, shape, or the arrangement of their constituents. In this work, we propose a 2D hybrid metallic polymeric nanostructure based on the octupolar framework with enhanced sensing property. We analyze its plasmonic features both numerically and experimentally, demonstrating the higher values of their relevant figures of merit: we estimated a surface-enhanced Raman spectroscopy (SERS) enhancement factor of 9 × 107 and a SPR bulk sensitivity of 430 nm/RIU. In addition, our nanostructure exhibits a dual resonance in the visible and near-infrared region, enabling our system toward multispectral plasmonic analysis. Finally, we illustrate our design engineering strategy as enabled by electron beam lithography by the outstanding performance of a SERS-based biosensor that targets the Shiga toxin 2a, a clinically relevant bacterial toxin. To the best of our knowledge, this is the first time that a SERS fingerprint of this toxin has been evidenced.
Collapse
Affiliation(s)
- M. Rippa
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
| | - D. Sagnelli
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
| | - A. Vestri
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
| | - V. Marchesano
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
| | - B. Munari
- Dipartimento
di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia
Generale, Università di Bologna, 40126 Bologna, Italy
| | - D. Carnicelli
- Dipartimento
di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia
Generale, Università di Bologna, 40126 Bologna, Italy
| | - E. Varrone
- Dipartimento
di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia
Generale, Università di Bologna, 40126 Bologna, Italy
| | - M. Brigotti
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
- Dipartimento
di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia
Generale, Università di Bologna, 40126 Bologna, Italy
| | - R. Tozzoli
- Laboratorio
Nazionale di Riferimento per E. coli, Dipartimento di Sicurezza Alimentare,
Nutrizione e Sanità Pubblica Veterinaria, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - M. Montalbano
- Laboratorio
Nazionale di Riferimento per E. coli, Dipartimento di Sicurezza Alimentare,
Nutrizione e Sanità Pubblica Veterinaria, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - S. Morabito
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
- Laboratorio
Nazionale di Riferimento per E. coli, Dipartimento di Sicurezza Alimentare,
Nutrizione e Sanità Pubblica Veterinaria, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - J. Zhou
- Institute
of Photonics, Faculty of Science, Ningbo
University, 315211 Ningbo, People’s
Republic of China
| | - J. Zyss
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
- Lumière,
Matière et Interfaces (LUMIN) Laboratory, Institut d’Alembert,
Ecole Normale Supérieure Paris-Saclay, Université Paris Saclay, 91190 Gif sur Yvette, France
| | - L. Petti
- Institute
of Applied Sciences and Intelligent Systems “E. Caianiello”
of CNR, 80072 Pozzuoli, Italy
| |
Collapse
|
|
5
|
Shiga Toxin 2a Induces NETosis via NOX-Dependent Pathway. Biomedicines 2021; 9:biomedicines9121807. [PMID: 34944623 PMCID: PMC8698832 DOI: 10.3390/biomedicines9121807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) infection is the most common cause of hemolytic uremic syndrome (HUS), one of the main causes of acute kidney injury in children. Stx plays an important role in endothelium damage and pathogenesis of STEC-HUS. However, the effects of Stx on neutrophils and neutrophil extracellular trap (NET) formation are not well understood. In this study, we investigated how Stx2a affects NET formation and NETotic pathways (NADPH or NOX-dependent and -independent) using neutrophils isolated from healthy donors and patients with STEC-HUS, during the acute and recovery phase of the disease. Stx2a dose-dependently induced NETosis in neutrophils isolated from both healthy controls and STEC-HUS patients. NETosis kinetics and mechanistic data with pathway-specific inhibitors including diphenyleneiodonium (DPI)-, ERK-, and P38-inhibitors showed that Stx2a-induced NETosis via the NOX-dependent pathway. Neutrophils from STEC-HUS patients in the acute phase showed less ROS and NETs formation compared to neutrophils of the recovery phase of the disease and in healthy controls. NETs induced by Stx2a may lead to the activation of endothelial cells, which might contribute to the manifestation of thrombotic microangiopathy in STEC-HUS.
Collapse
|
|
6
|
Heinisch L, Krause M, Roth A, Barth H, Schmidt H. Cytotoxic Effects of Recombinant StxA2-His in the Absence of Its Corresponding B-Subunit. Toxins (Basel) 2021; 13:toxins13050307. [PMID: 33925951 PMCID: PMC8145687 DOI: 10.3390/toxins13050307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 11/16/2022] Open
Abstract
AB5 protein toxins are produced by certain bacterial pathogens and are composed of an enzymatically active A-subunit and a B-subunit pentamer, the latter being responsible for cell receptor recognition, cellular uptake, and transport of the A-subunit into the cytosol of eukaryotic target cells. Two members of the AB5 toxin family were described in Shiga toxin-producing Escherichia coli (STEC), namely Shiga toxin (Stx) and subtilase cytotoxin (SubAB). The functional paradigm of AB toxins includes the B-subunit being mandatory for the uptake of the toxin into its target cells. Recent studies have shown that this paradigm cannot be maintained for SubAB, since SubA alone was demonstrated to intoxicate human epithelial cells in vitro. In the current study, we raised the hypothesis that this may also be true for the A-subunit of the most clinically relevant Stx-variant, Stx2a. After separate expression and purification, the recombinant Stx2a subunits StxA2a-His and StxB2a-His were applied either alone or in combination in a 1:5 molar ratio to Vero B4, HeLa, and HCT-116 cells. For all cell lines, a cytotoxic effect of StxA2a-His alone was detected. Competition experiments with Stx and SubAB subunits in combination revealed that the intoxication of StxA2a-His was reduced by addition of SubB1-His. This study showed that the enzymatic subunit StxA2a alone was active on different cells and might therefore play a yet unknown role in STEC disease development.
Collapse
Affiliation(s)
- Laura Heinisch
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, Garbenstraße 28, University of Hohenheim, 70599 Stuttgart, Germany; (L.H.); (M.K.); (A.R.)
| | - Maike Krause
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, Garbenstraße 28, University of Hohenheim, 70599 Stuttgart, Germany; (L.H.); (M.K.); (A.R.)
| | - Astrid Roth
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, Garbenstraße 28, University of Hohenheim, 70599 Stuttgart, Germany; (L.H.); (M.K.); (A.R.)
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany;
| | - Herbert Schmidt
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, Garbenstraße 28, University of Hohenheim, 70599 Stuttgart, Germany; (L.H.); (M.K.); (A.R.)
- Correspondence: ; Tel.: +49-711-459-22305
| |
Collapse
|
|
7
|
Varrone E, Carnicelli D, Brigotti M. Extracellular Vesicles and Renal Endothelial Cells: A Fatal Attraction in Hemolytic Uremic Syndrome. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:795-804. [PMID: 33652019 DOI: 10.1016/j.ajpath.2021.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/22/2021] [Accepted: 02/10/2021] [Indexed: 12/14/2022]
Abstract
This review focuses on typical hemolytic uremic syndrome (HUS), a life-threatening sequela of human infections caused, particularly in children, by Shiga toxin-producing Escherichia coli strains. Thrombotic microangiopathy of the brain and the kidney is the end point of toxin action, resulting in the hallmarks of HUS (ie, thrombocytopenia, anemia, and acute renal failure). A growing body of evidence points to the role of extracellular vesicles released in the blood of patients by toxin-challenged circulating cells (monocytes, neutrophils, and erythrocytes) and platelets, as a key factor in the pathogenesis of HUS. This review provides i) an updated description of the pathogenesis of Shiga toxin-producing E. coli infections; ii) an analysis of blood cell-derived extracellular vesicles, and of their parent cells, as triggering factors in HUS; and iii) a model explaining why Shiga toxin-containing vesicles dock preferentially to the endothelia of target organs.
Collapse
Affiliation(s)
- Elisa Varrone
- Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna, Italy
| | - Domenica Carnicelli
- Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna, Italy
| | - Maurizio Brigotti
- Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna, Italy.
| |
Collapse
|
|
8
|
Rocchetti L, Munari B, Varrone E, Porcellini E, Orth-Höller D, Würzner R, Carnicelli D, Brigotti M. Method for the Detection of the Cleaved Form of Shiga Toxin 2a Added to Normal Human Serum. Toxins (Basel) 2021; 13:toxins13020094. [PMID: 33530614 PMCID: PMC7911550 DOI: 10.3390/toxins13020094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/14/2021] [Accepted: 01/21/2021] [Indexed: 11/16/2022] Open
Abstract
The pathogenesis of Escherichia coli-induced hemolytic uremic syndrome (eHUS) caused by infections with pathogenic Shiga toxin (Stx) producing E. coli (STEC) is centered on bacterial (e.g., Stx) and host factors (circulating cells, complement system, serum proteins) whose interaction is crucial for the immediate outcome and for the development of this life-threatening sequela. Stx2a, associated to circulating cells (early toxemia) or extracellular vesicles (late toxemia) in blood, is considered the main pathogenic factor in the development of eHUS. Recently, it was found that the functional properties of Stx2a (binding to circulating cells and complement components) change according to modifications of the structure of the toxin, i.e., after a single cleavage of the A subunit resulting in two fragments, A1 and A2, linked by a disulfide bridge. Herein, we describe a method to be used for the detection of the cleaved form of Stx2a in the serum of STEC-infected or eHUS patients. The method is based on the detection of the boosted inhibitory activity of the cleaved toxin, upon treatment with reducing agents, on a rabbit cell-free translation system reconstituted with human ribosomes. The method overcomes the technical problem caused by the presence of inhibitors of translation in human serum that have been stalled by the addition of RNAase blockers and by treatment with immobilized protein G. This method, allowing the detection of Stx2a at concentrations similar to those found by ELISA in the blood of STEC-infected patients, could be a useful tool to study the contribution of the cleaved form of Stx2a in the pathogenesis of eHUS.
Collapse
Affiliation(s)
- Lucrezia Rocchetti
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (L.R.); (B.M.); (E.V.); (E.P.); (D.C.)
| | - Beatrice Munari
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (L.R.); (B.M.); (E.V.); (E.P.); (D.C.)
| | - Elisa Varrone
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (L.R.); (B.M.); (E.V.); (E.P.); (D.C.)
| | - Elisa Porcellini
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (L.R.); (B.M.); (E.V.); (E.P.); (D.C.)
| | - Dorothea Orth-Höller
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (D.O.-H.); (R.W.)
| | - Reinhard Würzner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (D.O.-H.); (R.W.)
| | - Domenica Carnicelli
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (L.R.); (B.M.); (E.V.); (E.P.); (D.C.)
| | - Maurizio Brigotti
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Via San Giacomo 14, 40126 Bologna, Italy; (L.R.); (B.M.); (E.V.); (E.P.); (D.C.)
- Correspondence: ; Tel.: +39-051-209-4716
| |
Collapse
|
|
9
|
Shiga Toxin 2a Binds to Complement Components C3b and C5 and Upregulates Their Gene Expression in Human Cell Lines. Toxins (Basel) 2020; 13:toxins13010008. [PMID: 33374102 PMCID: PMC7824702 DOI: 10.3390/toxins13010008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 01/06/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) infections can cause EHEC-associated hemolytic uremic syndrome (eHUS) via its main virulent factor, Shiga toxins (Stxs). Complement has been reported to be involved in the progression of eHUS. The aim of this study was to investigate the interactions of the most effective subtype of the toxin, Stx2a, with pivotal complement proteins C3b and C5. The study further examined the effect of Stx2a stimulation on the transcription and synthesis of these complement proteins in human target cell lines. Binding of Stx2a to C3b and C5 was evaluated by ELISA. Kidney and gut cell lines (HK-2 and HCT-8) were stimulated with varied concentrations of Stx2a. Subsequent evaluation of complement gene transcription was studied by real-time PCR (qPCR), and ELISAs and Western blots were performed to examine protein synthesis of C3 and C5 in supernatants and lysates of stimulated HK-2 cells. Stx2a showed a specific binding to C3b and C5. Gene transcription of C3 and C5 was upregulated with increasing concentrations of Stx2a in both cell lines, but protein synthesis was not. This study demonstrates the binding of Stx2a to complement proteins C3b and C5, which could potentially be involved in regulating complement during eHUS infection, supporting further investigations into elucidating the role of complement in eHUS pathogenesis.
Collapse
|
|
10
|
Feitz WJC, van de Kar NCAJ, Cheong I, van der Velden TJAM, Ortiz-Sandoval CG, Orth-Höller D, van den Heuvel LPJW, Licht C. Primary Human Derived Blood Outgrowth Endothelial Cells: An Appropriate In Vitro Model to Study Shiga Toxin Mediated Damage of Endothelial Cells. Toxins (Basel) 2020; 12:toxins12080483. [PMID: 32751286 PMCID: PMC7472281 DOI: 10.3390/toxins12080483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/19/2020] [Accepted: 07/21/2020] [Indexed: 11/30/2022] Open
Abstract
Hemolytic uremic syndrome (HUS) is a rare disease primarily characterized by hemolytic anemia, thrombocytopenia, and acute renal failure. Endothelial damage is the hallmark of the pathogenesis of HUS with an infection with the Shiga toxin (Stx) producing Escherichia coli (STEC-HUS) as the main underlying cause in childhood. In this study, blood outgrowth endothelial cells (BOECs) were isolated from healthy donors serving as controls and patients recovered from STEC-HUS. We hypothesized that Stx is more cytotoxic for STEC-HUS BOECs compared to healthy donor control BOECs explained via a higher amount of Stx bound to the cell surface. Binding of Shiga toxin-2a (Stx2a) was investigated and the effect on cytotoxicity, protein synthesis, wound healing, and cell proliferation was studied in static conditions. Results show that BOECs are highly susceptible for Stx2a. Stx2a is able to bind to the cell surface of BOECs with cytotoxicity in a dose-dependent manner as a result. Pre-treatment with tumor necrosis factor alpha (TNF-α) results in enhanced Stx binding with 20–30% increased lactate dehydrogenase (LDH) release. Endothelial wound healing is delayed in a Stx2a-rich environment; however, this is not caused by an effect on the proliferation rate of BOECs. No significant differences were found between control BOECs and BOECs from recovered STEC-HUS patients in terms of Stx2a binding and inhibition of protein synthesis.
Collapse
Affiliation(s)
- Wouter J. C. Feitz
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud Institute for Molecular Life Sciences, Radboudumc, 6525 GA Nijmegen, The Netherlands; (W.J.C.F.); (N.C.A.J.v.d.K.); (T.J.A.M.v.d.V.); (L.P.J.W.v.d.H.)
- Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (I.C.); (C.G.O.-S.)
| | - Nicole C. A. J. van de Kar
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud Institute for Molecular Life Sciences, Radboudumc, 6525 GA Nijmegen, The Netherlands; (W.J.C.F.); (N.C.A.J.v.d.K.); (T.J.A.M.v.d.V.); (L.P.J.W.v.d.H.)
| | - Ian Cheong
- Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (I.C.); (C.G.O.-S.)
| | - Thea J. A. M. van der Velden
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud Institute for Molecular Life Sciences, Radboudumc, 6525 GA Nijmegen, The Netherlands; (W.J.C.F.); (N.C.A.J.v.d.K.); (T.J.A.M.v.d.V.); (L.P.J.W.v.d.H.)
| | - Carolina G. Ortiz-Sandoval
- Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (I.C.); (C.G.O.-S.)
| | - Dorothea Orth-Höller
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Lambert P. J. W. van den Heuvel
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud Institute for Molecular Life Sciences, Radboudumc, 6525 GA Nijmegen, The Netherlands; (W.J.C.F.); (N.C.A.J.v.d.K.); (T.J.A.M.v.d.V.); (L.P.J.W.v.d.H.)
- Department of Development and Regeneration, Department of Pediatric Nephrology, KU, 3000 Leuven, Belgium
| | - Christoph Licht
- Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (I.C.); (C.G.O.-S.)
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Department of Pediatrics, University of Toronto, Toronto, ON M5G 1X8, Canada
- Correspondence: ; Tel.: +1-416-813-7654 (ext. 309343)
| |
Collapse
|
|
11
|
Molecular Biology of Escherichia Coli Shiga Toxins' Effects on Mammalian Cells. Toxins (Basel) 2020; 12:toxins12050345. [PMID: 32456125 PMCID: PMC7290813 DOI: 10.3390/toxins12050345] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Shiga toxins (Stxs), syn. Vero(cyto)toxins, are potent bacterial exotoxins and the principal virulence factor of enterohemorrhagic Escherichia coli (EHEC), a subset of Shiga toxin-producing E. coli (STEC). EHEC strains, e.g., strains of serovars O157:H7 and O104:H4, may cause individual cases as well as large outbreaks of life-threatening diseases in humans. Stxs primarily exert a ribotoxic activity in the eukaryotic target cells of the mammalian host resulting in rapid protein synthesis inhibition and cell death. Damage of endothelial cells in the kidneys and the central nervous system by Stxs is central in the pathogenesis of hemolytic uremic syndrome (HUS) in humans and edema disease in pigs. Probably even more important, the toxins also are capable of modulating a plethora of essential cellular functions, which eventually disturb intercellular communication. The review aims at providing a comprehensive overview of the current knowledge of the time course and the consecutive steps of Stx/cell interactions at the molecular level. Intervention measures deduced from an in-depth understanding of this molecular interplay may foster our basic understanding of cellular biology and microbial pathogenesis and pave the way to the creation of host-directed active compounds to mitigate the pathological conditions of STEC infections in the mammalian body.
Collapse
|
|
12
|
Lingwood C. Verotoxin Receptor-Based Pathology and Therapies. Front Cell Infect Microbiol 2020; 10:123. [PMID: 32296648 PMCID: PMC7136409 DOI: 10.3389/fcimb.2020.00123] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/05/2020] [Indexed: 12/22/2022] Open
Abstract
Verotoxin, VT (aka Shiga toxin,Stx) is produced by enterohemorrhagic E. coli (EHEC) and is the key pathogenic factor in EHEC-induced hemolytic uremic syndrome (eHUS-hemolytic anemia/thrombocytopenia/glomerular infarct) which can follow gastrointestinal EHEC infection, particularly in children. This AB5 subunit toxin family bind target cell globotriaosyl ceramide (Gb3), a glycosphingolipid (GSL) (aka CD77, pk blood group antigen) of the globoseries of neutral GSLs, initiating lipid raft-dependent plasma membrane Gb3 clustering, membrane curvature, invagination, scission, endosomal trafficking, and retrograde traffic via the TGN to the Golgi, and ER. In the ER, A/B subunits separate and the A subunit hijacks the ER reverse translocon (dislocon-used to eliminate misfolded proteins-ER associated degradation-ERAD) for cytosolic access. This property has been used to devise toxoid-based therapy to temporarily block ERAD and rescue the mutant phenotype of several genetic protein misfolding diseases. The A subunit avoids cytosolic proteosomal degradation, to block protein synthesis via its RNA glycanase activity. In humans, Gb3 is primarily expressed in the kidney, particularly in the glomerular endothelial cells. Here, Gb3 is in lipid rafts (more ordered membrane domains which accumulate GSLs/cholesterol) whereas renal tubular Gb3 is in the non-raft membrane fraction, explaining the basic pathology of eHUS (glomerular endothelial infarct). Females are more susceptible and this correlates with higher renal Gb3 expression. HUS can be associated with encephalopathy, more commonly following verotoxin 2 exposure. Gb3 is expressed in the microvasculature of the brain. All members of the VT family bind Gb3, but with varying affinity. VT2e (pig edema toxin) binds Gb4 preferentially. Verotoxin-specific therapeutics based on chemical analogs of Gb3, though effective in vitro, have failed in vivo. While some analogs are effective in animal models, there are no good rodent models of eHUS since Gb3 is not expressed in rodent glomeruli. However, the mouse mimics the neurological symptoms more closely and provides an excellent tool to assess therapeutics. In addition to direct cytotoxicity, other factors including VT–induced cytokine release and aberrant complement cascade, are now appreciated as important in eHUS. Based on atypical HUS therapy, treatment of eHUS patients with anticomplement antibodies has proven effective in some cases. A recent switch using stem cells to try to reverse, rather than prevent VT induced pathology may prove a more effective methodology.
Collapse
Affiliation(s)
- Clifford Lingwood
- Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
| |
Collapse
|
|
13
|
Brigotti M, Orth-Höller D, Carnicelli D, Porcellini E, Galassi E, Tazzari PL, Ricci F, Manoli F, Manet I, Talasz H, Lindner HH, Speth C, Erbeznik T, Fuchs S, Posch W, Chatterjee S, Würzner R. The structure of the Shiga toxin 2a A-subunit dictates the interactions of the toxin with blood components. Cell Microbiol 2019; 21:e13000. [PMID: 30578712 PMCID: PMC6492301 DOI: 10.1111/cmi.13000] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/06/2018] [Accepted: 12/17/2018] [Indexed: 12/29/2022]
Abstract
Hemolytic uremic syndrome (eHUS) is a severe complication of human infections with Shiga toxins (Stxs)-producing Escherichia coli. A key step in the pathogenesis of eHUS is the interaction of Stxs with blood components before the targeting of renal endothelial cells. Here, we show that a single proteolytic cleavage in the Stx2a A-subunit, resulting into two fragments (A1 and A2) linked by a disulfide bridge (cleaved Stx2a), dictates different binding abilities. Uncleaved Stx2a was confirmed to bind to human neutrophils and to trigger leukocyte/platelet aggregate formation, whereas cleaved Stx2a was ineffective. Conversely, binding of complement factor H was confirmed for cleaved Stx2a and not for uncleaved Stx2a. It is worth noting that uncleaved and cleaved Stx2a showed no differences in cytotoxicity for Vero cells or Raji cells, structural conformation, and contaminating endotoxin. These results have been obtained by comparing two Stx2a batches, purified in different laboratories by using different protocols, termed Stx2a(cl; cleaved toxin, Innsbruck) and Stx2a(uncl; uncleaved toxin, Bologna). Stx2a(uncl) behaved as Stx2a(cl) after mild trypsin treatment. In this light, previous controversial results obtained with purified Stx2a has to be critically re-evaluated; furthermore, characterisation of the structure of circulating Stx2a is mandatory to understand eHUS-pathogenesis and to develop therapeutic approaches.
Collapse
Affiliation(s)
- Maurizio Brigotti
- Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia Generale, Università di Bologna, Bologna, Italy
| | - Dorothea Orth-Höller
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Domenica Carnicelli
- Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia Generale, Università di Bologna, Bologna, Italy
| | - Elisa Porcellini
- Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia Generale, Università di Bologna, Bologna, Italy
| | - Elisabetta Galassi
- Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia Generale, Università di Bologna, Bologna, Italy
| | - Pier Luigi Tazzari
- Servizio di Immunoematologia e Trasfusionale, Ospedale S. Orsola-Malpighi, Bologna, Italy
| | - Francesca Ricci
- Servizio di Immunoematologia e Trasfusionale, Ospedale S. Orsola-Malpighi, Bologna, Italy
| | - Francesco Manoli
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Ilse Manet
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Heribert Talasz
- Division of Clinical Biochemistry, Biocentre, Medical University of Innsbruck, Innsbruck, Austria
| | - Herbert H Lindner
- Division of Clinical Biochemistry, Biocentre, Medical University of Innsbruck, Innsbruck, Austria
| | - Cornelia Speth
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Erbeznik
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Stefan Fuchs
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Wilfried Posch
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Sneha Chatterjee
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Reinhard Würzner
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|