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Owen Bonello R, Pitak MB, Tizzard GJ, Coles SJ, Fallis IA, Pope SJ. Aryl, bi-functionalised imidazo[4,5-f]-1,10-phenanthroline ligands and their luminescent rhenium(I) complexes. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.116179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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2
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Metwally NH, Koraa TH, Sanad SMH. Green one-pot synthesis and in vitro antibacterial screening of pyrano[2,3- c]pyrazoles, 4 H-chromenes and pyrazolo[1,5- a]pyrimidines using biocatalyzed pepsin. SYNTHETIC COMMUN 2022. [DOI: 10.1080/00397911.2022.2074301] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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3
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Nack T, Dinis de Oliveira T, Weber S, Schols D, Balzarini J, Meier C. γ-Ketobenzyl-Modified Nucleoside Triphosphate Prodrugs as Potential Antivirals. J Med Chem 2020; 63:13745-13761. [PMID: 33186038 DOI: 10.1021/acs.jmedchem.0c01293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The antiviral activity of nucleoside reverse transcriptase inhibitors is often hampered by insufficient phosphorylation. Nucleoside triphosphate analogues are presented, in which the γ-phosphate was covalently modified by a non-bioreversible, lipophilic 4-alkylketobenzyl moiety. Interestingly, primer extension assays using human immunodeficiency virus reverse transcriptase (HIV-RT) and three DNA-polymerases showed a high selectivity of these γ-modified nucleoside triphosphates to act as substrates for HIV-RT, while they proved to be nonsubstrates for DNA-polymerases α, β, and γ. In contrast to d4TTP, the γ-modified d4TTPs showed a high resistance toward dephosphorylation in cell extracts. A series of acyloxybenzyl-prodrugs of these γ-ketobenzyl nucleoside triphosphates was prepared. The aim was the intracellular delivery of a stable γ-modified nucleoside triphosphate to increase the selectivity of such compounds to act in infected versus noninfected cells. Delivery of γ-ketobenzyl-d4TTPs was proven in T-lymphocyte cell extracts. The prodrugs were potent inhibitors of HIV-1/2 in cultures of infected CEM/0 cells and more importantly in thymidine kinase-deficient CD4+ T-cells.
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Affiliation(s)
- Tobias Nack
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Thiago Dinis de Oliveira
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Stefan Weber
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Dominique Schols
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Jan Balzarini
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Chris Meier
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
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4
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Kumar V, Saha A, Roy K. In silico modeling for dual inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes in Alzheimer's disease. Comput Biol Chem 2020; 88:107355. [PMID: 32801088 DOI: 10.1016/j.compbiolchem.2020.107355] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 01/11/2023]
Abstract
In this research, we have implemented two-dimensional quantitative structure-activity relationship (2D-QSAR) modeling using two different datasets, namely, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzyme inhibitors. A third dataset has been derived based on their selectivity and used for the development of partial least squares (PLS) based regression models. The developed models were extensively validated using various internal and external validation parameters. The features appearing in the model against AChE enzyme suggest that a small ring size, higher number of -CH2- groups, higher number of secondary aromatic amines and higher number of aromatic ketone groups may contribute to the inhibitory activity. The features obtained from the model against BuChE enzyme suggest that the sum of topological distances between two nitrogen atoms, higher number of fragments X-C(=X)-X, higher number of secondary aromatic amides, fragment R--CR-X may be more favorable for inhibition. The features obtained from selectivity based model suggest that the number of aromatic ethers, unsaturation content relative to the molecular size and molecular shape may be more specific for the inhibition of the AChE enzyme in comparison to the BuChE enzyme. Moreover, we have implemented the molecular docking studies using the most and least active molecules from the datasets in order to identify the binding pattern between ligand and target enzyme. The obtained information is then correlated with the essential structural features associated with the 2D-QSAR models.
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Affiliation(s)
- Vinay Kumar
- Drug Theoretics and Cheminformatics Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700032, India
| | - Achintya Saha
- Department of Chemical Technology, University of Calcutta, 92 A P C Road, Kolkata 700 009, India
| | - Kunal Roy
- Drug Theoretics and Cheminformatics Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700032, India.
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Lin L, Olson ME, Eubanks LM, Janda KD. Strategies to Counteract Botulinum Neurotoxin A: Nature's Deadliest Biomolecule. Acc Chem Res 2019; 52:2322-2331. [PMID: 31322847 DOI: 10.1021/acs.accounts.9b00261] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Botulinum neurotoxin serotype A (BoNT/A), marketed commercially as Botox, is the most toxic substance known to man with an estimated intravenous lethal dose (LD50) of 1-2 ng/kg in humans. Despite its widespread use in cosmetic and medicinal applications, no postexposure therapeutics are available for the reversal of intoxication in the event of medical malpractice or bioterrorism. Accordingly, the Centers for Disease Control and Prevention categorizes BoNT/A as a Category A pathogen, posing the highest risk to national security and public health as a result of the ease with which BoNT/A can be weaponized and disseminated. BoNT/A-mediated lethality results from neurons impeded from releasing acetylcholine, which ultimately causes muscle paralysis and possible death by asphyxiation with the loss of diaphragm function. Currently, the only available respite for BoNT/A poisoning is antibody-based therapy; however, this intervention is only effective within 12-24 h postexposure. Small molecule therapeutics remain the only opportunity to reverse BoNT/A intoxication after neuronal poisoning and are urgently needed. Nevertheless, no small molecule BoNT/A inhibitors have reached the clinic or even advanced to clinical trials. This Account highlights the accomplishments and existing challenges facing BoNT/A drug discovery today. Using the comprehensive body of work from our laboratory, we illustrate our nearly two-decade endeavor to discover a clinically relevant BoNT/A inhibitor. Specifically, a discussion on the identification and characterization of new chemical leads, the development of in vitro and in vivo assays, and pertinent discoveries in BoNT/A structural biology related to small molecule inhibition is presented. Lead discovery efforts in our laboratory have leveraged both in vitro high-throughput screening and rational design, and an array of mechanistic strategies for inhibiting BoNT/A has been discovered, including noncovalent inhibition, metal-binding active site inhibition, covalent inhibition, and α- and β-exosite inhibition. We contrast the strengths and weaknesses of each of these mechanistic strategies and propose the most favorable approach for success. Finally, we discuss multiple serendipitous discoveries of antibotulism small molecules with alternative mechanisms of action. Remaining challenges facing clinically relevant BoNT/A inhibition are presented and analyzed, including the current inability to reconcile toxin half-life (months to greater than one year) in neurons with in vivo pharmaceutical lifetimes and reoccurring inconsistencies between in vitro, cellular, and in vivo translation. Our Account of BoNT/A chemical research emphasizes the present accomplishments and critically analyzes the remaining obstacles for drug discovery. Importantly, we call for an increased focus on the discovery of safe and effective covalent inhibitors of BoNT/A that compete with the inherent half-life of the toxin.
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Affiliation(s)
- Lucy Lin
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The WIRM Institute for Research & Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Margaret E. Olson
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The WIRM Institute for Research & Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Lisa M. Eubanks
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The WIRM Institute for Research & Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Kim D. Janda
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The WIRM Institute for Research & Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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6
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Bradford AB, Machamer JB, Russo TM, McNutt PM. 3,4-diaminopyridine reverses paralysis in botulinum neurotoxin-intoxicated diaphragms through two functionally distinct mechanisms. Toxicol Appl Pharmacol 2018; 341:77-86. [PMID: 29366638 DOI: 10.1016/j.taap.2018.01.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/15/2018] [Accepted: 01/18/2018] [Indexed: 01/11/2023]
Abstract
Botulinum neurotoxins (BoNTs) are exceedingly potent neurological poisons that prevent neurotransmitter release from peripheral nerve terminals by cleaving presynaptic proteins required for synaptic vesicle fusion. The ensuing neuromuscular paralysis causes death by asphyxiation. Although no antidotal treatments exist to block toxin activity within the nerve terminal, aminopyridine antagonists of voltage-gated potassium channels have been proposed as symptomatic treatments for botulism toxemia. However, clinical evaluation of aminopyridines as symptomatic treatments for botulism has been inconclusive, in part because mechanisms responsible for reversal of paralysis in BoNT-poisoned nerve terminals are not understood. Here we measured the effects of 3,4-diaminopyridine (DAP) on phrenic nerve-elicited diaphragm contraction and end-plate potentials at various times after intoxication with BoNT serotypes A, B, or E. We found that DAP-mediated increases in quantal content promote neurotransmission from intoxicated nerve terminals through two functionally distinguishable mechanisms. First, DAP increases the probability of neurotransmission at non-intoxicated release sites. This mechanism is serotype-independent, becomes less effective as nerve terminals become progressively impaired, and remains susceptible to ongoing intoxication. Second, DAP elicits persistent production of toxin-resistant endplate potentials from nerve terminals fully intoxicated by BoNT/A, but not serotypes B or E. Since this effect appears specific to BoNT/A intoxication, we propose that DAP treatment enables BoNT/A-cleaved SNAP-25 to productively engage in fusogenic release by increasing the opportunity for low-efficiency fusion events. These findings have important implications for DAP as a botulism therapeutic by defining conditions under which DAP may be clinically effective in reversing botulism symptoms.
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Affiliation(s)
- Aaron B Bradford
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA
| | - James B Machamer
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA
| | - Trisha M Russo
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA
| | - Patrick M McNutt
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA.
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Use-dependent potentiation of voltage-gated calcium channels rescues neurotransmission in nerve terminals intoxicated by botulinum neurotoxin serotype A. Sci Rep 2017; 7:15862. [PMID: 29158500 PMCID: PMC5696531 DOI: 10.1038/s41598-017-16064-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/06/2017] [Indexed: 01/27/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are highly potent toxins that cleave neuronal SNARE proteins required for neurotransmission, causing flaccid paralysis and death by asphyxiation. Currently, there are no clinical treatments to delay or reverse BoNT-induced blockade of neuromuscular transmission. While aminopyridines have demonstrated varying efficacy in transiently reducing paralysis following BoNT poisoning, the precise mechanisms by which aminopyridines symptomatically treat botulism are not understood. Here we found that activity-dependent potentiation of presynaptic voltage-gated calcium channels (VGCCs) underlies 3,4-diaminopyridine (3,4-DAP)-mediated rescue of neurotransmission in central nervous system synapses and mouse diaphragm neuromuscular junctions fully intoxicated by BoNT serotype A. Combinatorial treatments with 3,4-DAP and VGCC agonists proved synergistic in restoring suprathreshold endplate potentials in mouse diaphragms fully intoxicated by BoNT/A. In contrast, synapses fully intoxicated by BoNT serotypes D or E were refractory to synaptic rescue by any treatment. We interpret these data to propose that increasing the duration or extent of VGCC activation prolongs the opportunity for low-efficiency fusion by fusogenic complexes incorporating BoNT/A-cleaved SNAP-25. The identification of VGCC agonists that rescue neurotransmission in BoNT/A-intoxicated synapses provides compelling evidence for potential therapeutic utility in some cases of human botulism.
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8
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Pirazzini M, Rossetto O. Challenges in searching for therapeutics against Botulinum Neurotoxins. Expert Opin Drug Discov 2017; 12:497-510. [DOI: 10.1080/17460441.2017.1303476] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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9
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Novel securinine derivatives as topoisomerase I based antitumor agents. Eur J Med Chem 2016; 122:149-163. [DOI: 10.1016/j.ejmech.2016.06.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 06/06/2016] [Accepted: 06/13/2016] [Indexed: 11/19/2022]
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Feng L, Chen X, Liu S, Zhou Z, Yang R. Two-family outbreak of botulism associated with the consumption of smoked ribs in Sichuan Province, China. Int J Infect Dis 2014; 30:74-7. [PMID: 25448333 DOI: 10.1016/j.ijid.2014.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 10/01/2014] [Accepted: 10/25/2014] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND On September 22, 2013, two patients from Sichuan Province, China presented with symptoms of food-borne botulism, a rare but fatal illness caused by the consumption of foods containing Clostridium botulinum neurotoxins. METHODS Investigators reviewed the medical charts and food consumption histories, and interviewed patients and family members. Food samples and clinical specimens were tested for botulinum toxin and neurotoxin-producing Clostridium species by standard methods. RESULTS The first two index cases presented with cranial neuropathies and flaccid paralysis, and required mechanical ventilation. There were 12 confirmed outbreak-associated cases. Botulinum toxin type A was identified in the smoked ribs, and all of the patients had consumed the smoked ribs from the same local restaurant. The smoked ribs contained no added salt, sugar, or preservative. Botulinum toxin production likely resulted from the cold-smoking preparation method and inappropriate refrigeration. CONCLUSIONS Smoked ribs produced by a local restaurant, contaminated with type A botulism, was the contributor to this outbreak. The supervision of food safety should be strengthened to prevent future outbreaks in China.
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Affiliation(s)
- Ling Feng
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Xueping Chen
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Shujie Liu
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Zengrong Zhou
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Rong Yang
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China.
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11
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Harris TL, Lowery CA, Hixon MS, Janda KD. A platform stratifying a sequestering agent and a pharmacological antagonist as a means to negate botulinum neurotoxicity. ACS Chem Neurosci 2014; 5:632-6. [PMID: 25000171 DOI: 10.1021/cn500135h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Botulinum neurotoxicity is characterized by peripheral neuromuscular blockade/flaccid paralysis that can lead to respiratory failure and ultimately death. Current therapeutic options provide relief in a pre-exposure scenario, but there are no clinically approved postexposure medical countermeasures. Here, we introduce a platform that utilizes a combination of a toxin sequestering agent and a pharmacological antagonist to ablate botulinum neurotoxicity in a well-defined mouse lethality assay. The platform was constructed to allow for ready exchange of sequestering agent and/or pharmacological antagonist for therapeutic optimization. As such, we attempted to improve upon the pharmacological antagonist, a potassium channel blocker, 3,4-diaminopyridine, through a prodrug approach; thus, a complete kinetic decomposition pathway is described. These experiments provide the first proof-of-principle that a synergistic combination strategy can be used to reduce toxin burden in the peripheral using a sequestering antibody, while restoring muscle action via a pharmacological small molecule antagonist.
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Affiliation(s)
- Tyler L. Harris
- Departments
of Chemistry, Immunology and Microbial Sciences, and The Skaggs Institute
for Chemical Biology, The Scripps Research Institute, 10550 North
Torrey Pines Road, La Jolla, California 92037, United States
| | - Colin A. Lowery
- Departments
of Chemistry, Immunology and Microbial Sciences, and The Skaggs Institute
for Chemical Biology, The Scripps Research Institute, 10550 North
Torrey Pines Road, La Jolla, California 92037, United States
| | - Mark S. Hixon
- Department
of Discovery Biology, Takeda California, Inc., 10410 Science Center
Drive, San Diego, California 92121, United States
| | - Kim D. Janda
- Departments
of Chemistry, Immunology and Microbial Sciences, and The Skaggs Institute
for Chemical Biology, The Scripps Research Institute, 10550 North
Torrey Pines Road, La Jolla, California 92037, United States
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Anniballi F, Lonati D, Fiore A, Auricchio B, De Medici D, Locatelli CA. New targets in the search for preventive and therapeutic agents for botulism. Expert Rev Anti Infect Ther 2014; 12:1075-86. [PMID: 25089560 DOI: 10.1586/14787210.2014.945917] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Botulism is a severe neuroparalytic disease resulting from exposure to one of the most poisonous toxins to humans. Because of this high potency and the use of toxins as biological weapons, botulism is a public health concern and each case represents an emergency. Current therapy involves respiratory supportive care and anti-toxins administration. As a preventive measure, vaccination against toxins represents an effective strategy but is undesirable due the rarity of botulism and the effectiveness of toxins in treating several neuromuscular disorders. This paper summarizes the current issues in botulism treatment and prevention, highlighting the challenge for future researches.
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Affiliation(s)
- Fabrizio Anniballi
- Department of Veterinary Public Health and Food Safety, National Reference Centre for Botulism, Istituto Superiore di Sanità, Viale Regina Elena, 299 - 00161 Rome, Italy
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