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Wang J, Xu H, Zhang C, Chen J, Wang C, Li X, Zhang Y, Xie J. Serotype Features of 17 Suspected Cases of Foodborne Botulism in China 2019-2022 Revealed by a Multiplex Immuno-Endopep-MS Method. Front Microbiol 2022; 13:869874. [PMID: 35450283 PMCID: PMC9016322 DOI: 10.3389/fmicb.2022.869874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 03/04/2022] [Indexed: 11/13/2022] Open
Abstract
Diagnosis of botulism caused by multiple serotypes of botulinum neurotoxin (BoNT) is still a challenge due to the lack of a reliable detection method. The present study develops a feasible laboratorial method based on an isotope dilution Immuno-Endopep-MS to detect BoNTs and determine their serotypes and activities in clinical samples. Eleven positive foodborne botulism cases out of a total of 17 suspected cases in China, 2019–2022, were determined by the established method. Blood, urine, vomitus, gastric mucosa samples, and food samples were employed and evidenced to be suitable for the detection. Results showed that, although single type A-intoxication was still the first cause among these foodborne botulism cases, other causes involving type E, type B, and their mixed types were also determined, providing a glimpse to the serotype profile of botulism happened in recent years in China. Furthermore, in order to provide insights into in vivo profiles of toxin serotypes, a comprehensive analysis of clinical specimens collected from one family of four patients was performed during a clinically and therapeutically relevant time frame. Serotypes and concentrations of BoNT in specimens revealed a good correlation with symptoms and progresses of disease. Additionally, serum was proved to be more suitable for detection of BoNT/A with a detection window up to 12 days. A urine sample, although rarely reported for foodborne botulism diagnosis, was validated to be suitable for testing BoNTs, with a longer detection window up to 25 days. To the best of our knowledge, this is the first comprehensive analytical research on in vivo profiles of serotypes A, B, and E in different types of specimens from mixed botulism cases. Our method and findings facilitate the toxin detection and identification by clinical diagnostic laboratories.
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Affiliation(s)
- Jiang Wang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Hua Xu
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Cheng Zhang
- Yongding Road Outpatient Department, Jingnan Medical District of Chinese PLA General Hospital, Beijing, China
| | - Jia Chen
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Chunyan Wang
- Poisoning Treatment Department, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Xinying Li
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yajiao Zhang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Jianwei Xie
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
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2
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Current Developments in Diagnostic Assays for Laboratory Confirmation and Investigation of Botulism. J Clin Microbiol 2021; 60:e0013920. [PMID: 34586891 DOI: 10.1128/jcm.00139-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Detection of botulinum neurotoxin or isolation of the toxin producing organism is required for the laboratory confirmation of botulism in clinical specimens. In an effort to reduce animal testing required by the gold standard method of botulinum neurotoxin detection, the mouse bioassay, many technologies have been developed to detect and characterize the causative agent of botulism. Recent advancements in these technologies have led to improvements in technical performance of diagnostic assays; however, many emerging assays have not been validated for the detection of all serotypes in complex clinical and environmental matrices. Improvements to culture protocols, endopeptidase-based assays, and a variety of immunological and molecular methods have provided laboratories with a variety of testing options to evaluate and incorporate into their testing algorithms. While significant advances have been made to improve these assays, additional work is necessary to evaluate these methods in various clinical matrices and to establish standardized criteria for data analysis and interpretation.
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3
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Koike H, Kanda M, Hayashi H, Matsushima Y, Yoshikawa S, Ohba Y, Hayashi M, Nagano C, Sekimura K, Otsuka K, Kamiie J, Sasamoto T, Hashimoto T. Development of an alternative approach for detecting botulinum neurotoxin type A in honey: Analysis of non-toxic peptides with a reference labelled protein via liquid chromatography-tandem mass spectrometry. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2020; 37:1359-1373. [PMID: 32515305 DOI: 10.1080/19440049.2020.1766121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this study, we developed a reference labelled protein containing the partial amino acid sequence of botulinum neurotoxin type A (BoNTA). We also applied it as an internal standard to detect specific and non-toxic peptides originated from BoNTA in honey with the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Original proteins in the honey sample were collected through a two-step process that included solubilisation and trichloroacetic acid (TCA) precipitation. Solubilisation by adding water enabled processing of proteins in honey. TCA precipitation collected proteins without specific binding. The combination of protein alkylation and an appropriate enzyme-to-protein ratio ensured feasibility of tryptic digestion. A desalting process eliminated a large amount of salts and other tryptic peptides in the honey sample. The use of the reference labelled protein enabled compensation for tryptic digestion efficiency and electrospray ionisation efficiency based on LC-MS/MS measurement. After the peptide selection and protein BlastP analysis, five unique peptides were chosen. The non-toxic peptides originating from BoNTA were reliably detected using LC-MS/MS based on a multiple-reaction monitoring mode. Detection of several peptides ensured screening of BoNTA in honey samples. Based on the responses, the proteotypic peptide LYGIAINPNR was selected as the quantitative peptide. Due to maintaining the relative ion ratios, the selective transition completely identified the non-toxic peptides. The intensity of the transitions established a detection limit of BoNTA estimated to be 9.4 ng mL-1. Although extraction efficiency was not evaluated using the BoNTA standard, the results suggested this method may be used for quantification of BoNTA in honey. The method was applied to 19 honey samples purchased in Tokyo; none of them was found to contain the target toxin. Overall, the method is expected to accelerate BoNTA monitoring for food safety.
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Affiliation(s)
- Hiroshi Koike
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Maki Kanda
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Hairoshi Hayashi
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Yoko Matsushima
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Souichi Yoshikawa
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Yumi Ohba
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Momoka Hayashi
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Chieko Nagano
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Kotaro Sekimura
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Kenji Otsuka
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Junichi Kamiie
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University , Sagamihara, Japan
| | - Takeo Sasamoto
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
| | - Tsuneo Hashimoto
- Department of Food Safety, Tokyo Metropolitan Institute of Public Health , Tokyo, Japan
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4
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Rudnicka K, Durka K, Chwaluk P, Chmiela M. Metody stosowane do wykrywania i identyfikacji toksyn botulinowych w próbkach klinicznych i żywności*. POSTEP HIG MED DOSW 2020. [DOI: 10.5604/01.3001.0014.1439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Botulism is a severe neuroparalytic illness, which affects the nervous system. It is caused by botulinum neurotoxins (BoNTs), produced by anaerobic gram-positive bacteria Clostridium botulinum. There are 7 serotypes of BoNT A-G, but BoNT A/B/D/E plays a major role in botulism affecting humans. Foodborne botulism (classic botulism) is the most frequent
clinical manifestation occurring after consumption of food containing botulinum neurotoxins.
The diagnosis of botulism is based on clinical symptoms; however, recommended
and alternative laboratory methods are used to confirm the etiology of symptoms and the
identification of BoNT toxin type. The aim of this work was to present the epidemiology of
foodborne botulism in Poland and to gather and analyze the available diagnostic methods
that allow us to detect BoNT in clinical samples. Using the epidemiological reports of National
Institute of Hygiene in Poland and findings presented in the Przegląd Epidemiologiczny,
the incidence of classical botulism in Poland has been presented over a period of recent
18 years. Searching for the optimal diagnostic method for BoNT identification in various
samples, we have confronted the sensitivity and specificity of recently available alternative
methods with classical biological assay.
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Affiliation(s)
- Karolina Rudnicka
- Pracownia Gastroimmunologii, Katedra Immunologii i Biologii Infekcyjnej, Wydział Biologii i Ochrony Środowiska, Uniwersytet Łódzki
| | - Karolina Durka
- Pracownia Gastroimmunologii, Katedra Immunologii i Biologii Infekcyjnej, Wydział Biologii i Ochrony Środowiska, Uniwersytet Łódzki
| | - Paweł Chwaluk
- Wojewódzki Szpital Specjalistyczny w Białej Podlaskiej, Biała Podlaska
| | - Magdalena Chmiela
- Pracownia Gastroimmunologii, Katedra Immunologii i Biologii Infekcyjnej, Wydział Biologii i Ochrony Środowiska, Uniwersytet Łódzki
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5
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Kalb SR, Baudys J, Kiernan K, Wang D, Becher F, Barr JR. Proposed BoNT/A and /B Peptide Substrates Cannot Detect Multiple Subtypes in the Endopep-MS Assay. J Anal Toxicol 2020; 44:173-179. [PMID: 31287544 DOI: 10.1093/jat/bkz044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/24/2019] [Accepted: 04/27/2019] [Indexed: 11/14/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are a family of protein toxins consisting of seven known serotypes (BoNT/A-BoNT/G) and multiple subtypes within the serotypes, and all of which cause the disease botulism-a disease of great public health concern. Accurate detection of BoNTs in human clinical samples is therefore an important public health goal. To achieve this goal, our laboratory developed a mass spectrometry-based assay detecting the presence of BoNT via its enzymatic activity on a peptide substrate. Recently, publications reported the use of new peptide substrates to detect BoNT/A and /B with improved results over other peptide substrates. However, the authors did not provide results of their peptide substrate on multiple subtypes of BoNT. In this work, we describe the results of testing the new substrates with multiple BoNT/A and /B subtypes and find that the substrates cannot detect many subtypes of BoNT/A and /B.
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Affiliation(s)
- Suzanne R Kalb
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, National Center for Environmental Health, Buford Hwy, Northeast Atlanta, GA, USA
| | - Jakub Baudys
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, National Center for Environmental Health, Buford Hwy, Northeast Atlanta, GA, USA
| | - Kaitlyn Kiernan
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, National Center for Environmental Health, Buford Hwy, Northeast Atlanta, GA, USA
| | - Dongxia Wang
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, National Center for Environmental Health, Buford Hwy, Northeast Atlanta, GA, USA
| | - François Becher
- Service de Pharmacologie et Immunoanalyse, Laboratoire d'Etude du Métabolisme des Médicaments, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Institut National de la Recherche Agronomique, Université Paris Saclay, Gif-sur-Yvette, France
| | - John R Barr
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, National Center for Environmental Health, Buford Hwy, Northeast Atlanta, GA, USA
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6
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Wang D, Baudys J, Hoyt KM, Barr JR, Kalb SR. Further optimization of peptide substrate enhanced assay performance for BoNT/A detection by MALDI-TOF mass spectrometry. Anal Bioanal Chem 2017; 409:4779-4786. [PMID: 28573317 PMCID: PMC5519644 DOI: 10.1007/s00216-017-0421-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/04/2017] [Accepted: 05/16/2017] [Indexed: 02/07/2023]
Abstract
Rapid and sensitive detection of botulinum neurotoxins (BoNTs), which cause botulism, is essential in a public health emergency or bioterrorism event. We have previously developed a mass spectrometry (MS)-based functional method, Endopep-MS assay, for the fast detection and differentiation of all BoNT serotypes by affinity enriching the toxin and detecting the serotype-specific cleavage products of peptide substrates derived from the in vivo targets. To improve the performance of the Endopep-MS assay, we report here the further optimization of the peptide substrate for the detection of serotype A botulinum neurotoxins. An increased substrate cleavage was achieved by extending the original peptide N-terminus with optimized amino acid sequence, increasing the detection sensitivity of the method. In addition, the resistance of the substrate to nonspecific hydrolysis was dramatically improved by selectively substituting amino acids at the scissile bond and various other positions of the extended peptide. Moreover, incorporating the N-terminal hydrophobic residues dramatically improved the relative intensity of the cleavage products in the mass spectra. This allowed easy detection of the cleavage products, further enhancing the performance of the assay. The limit of detection for spiked serum sample was enhanced from 0.5 to 0.1 mouseLD50 and from 0.5 to 0.2 mouseLD50 for spiked stool. Mass spectra of optimized and old peptide substrates with BoNT/A ![]()
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Affiliation(s)
- Dongxia Wang
- National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, NE, Atlanta, GA, 30341, USA
| | - Jakub Baudys
- National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, NE, Atlanta, GA, 30341, USA
| | - Kaitlin M Hoyt
- National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, NE, Atlanta, GA, 30341, USA
| | - John R Barr
- National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, NE, Atlanta, GA, 30341, USA
| | - Suzanne R Kalb
- National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, NE, Atlanta, GA, 30341, USA.
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7
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Fabrication of a Novel Highly Sensitive and Selective Immunosensor for Botulinum Neurotoxin Serotype A Based on an Effective Platform of Electrosynthesized Gold Nanodendrites/Chitosan Nanoparticles. SENSORS 2017; 17:s17051074. [PMID: 28486408 PMCID: PMC5470464 DOI: 10.3390/s17051074] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 05/02/2017] [Accepted: 05/03/2017] [Indexed: 12/13/2022]
Abstract
In this work, a novel nanocomposite consisting of electrosynthesized gold nanodendrites and chitosan nanoparticles (AuNDs/CSNPs) has been prepared to fabricate an impedimetric immunosensor based on a screen printed carbon electrode (SPCE) for the rapid and sensitive immunoassay of botulinum neurotoxin A (BoNT/A). BoNT/A polyclonal antibody was immobilized on the nanocomposite-modified SPCE for the signal amplification. The structure of the prepared nanocomposite was investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The charge transfer resistance (RCT) changes were used to detect BoNT/A as the specific immuno-interactions at the immunosensor surface that efficiently limited the electron transfer of Fe(CN)63−/4− as a redox probe at pH = 7.4. A linear relationship was observed between the %∆RCT and the concentration logarithm of BoNT/A within the range of 0.2 to 230 pg·mL−1 with a detection limit (S/N = 3) of 0.15 pg·mL−1. The practical applicability of the proposed sensor was examined by evaluating the detection of BoNT/A in milk and serum samples with satisfactory recoveries. Therefore, the prepared immunosensor holds great promise for the fast, simple and sensitive detection of BoNT/A in various real samples.
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8
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Rosen O, Feldberg L, Dor E, Gura S, Zichel R. Optimization of SNAP-25-derived peptide substrate for improved detection of botulinum A in the Endopep-MS assay. Anal Biochem 2017; 528:34-37. [PMID: 28450105 DOI: 10.1016/j.ab.2017.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 12/24/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the most toxic proteins in nature. Endopeptidase-mass-spectrometry (Endopep-MS) is used as a specific and rapid in-vitro assay to detect BoNTs. In this assay, immunocaptured toxin cleaves a serotype-specific-peptide-substrate, and the cleavage products are then detected by MS. Here we describe the design of a new peptide substrate for improved detection of BoNT type A (BoNT/A). Our strategy was based on reported BoNT/A-SNAP-25 interactions integrated with analysis method efficiency considerations. Integration of the newly designed substrate led to a 10-fold increase in the assay sensitivity both in buffer and in clinically relevant samples.
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Affiliation(s)
- Osnat Rosen
- Department of Biotechnology, Israel Institute for Biological Research, Israel
| | - Liron Feldberg
- Department of Analytical Chemistry, Israel Institute for Biological Research, Israel
| | - Eyal Dor
- Department of Biotechnology, Israel Institute for Biological Research, Israel
| | - Sigalit Gura
- Department of Analytical Chemistry, Israel Institute for Biological Research, Israel
| | - Ran Zichel
- Department of Biotechnology, Israel Institute for Biological Research, Israel.
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9
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Kalb SR, Boyer AE, Barr JR. Mass Spectrometric Detection of Bacterial Protein Toxins and Their Enzymatic Activity. Toxins (Basel) 2015; 7:3497-511. [PMID: 26404376 PMCID: PMC4591662 DOI: 10.3390/toxins7093497] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/10/2015] [Accepted: 08/26/2015] [Indexed: 01/15/2023] Open
Abstract
Mass spectrometry has recently become a powerful technique for bacterial identification. Mass spectrometry approaches generally rely upon introduction of the bacteria into a matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometer with mass spectrometric recognition of proteins specific to that organism that form a reliable fingerprint. With some bacteria, such as Bacillus anthracis and Clostridium botulinum, the health threat posed by these organisms is not the organism itself, but rather the protein toxins produced by the organisms. One such example is botulinum neurotoxin (BoNT), a potent neurotoxin produced by C. botulinum. There are seven known serotypes of BoNT, A–G, and many of the serotypes can be further differentiated into toxin variants, which are up to 99.9% identical in some cases. Mass spectrometric proteomic techniques have been established to differentiate the serotype or toxin variant of BoNT produced by varied strains of C. botulinum. Detection of potent biological toxins requires high analytical sensitivity and mass spectrometry based methods have been developed to determine the enzymatic activity of BoNT and the anthrax lethal toxins produced by B. anthracis. This enzymatic activity, unique for each toxin, is assessed with detection of the toxin-induced cleavage of strategically designed peptide substrates by MALDI-TOF mass spectrometry offering unparalleled specificity. Furthermore, activity assays allow for the assessment of the biological activity of a toxin and its potential health risk. Such methods have become important diagnostics for botulism and anthrax. Here, we review mass spectrometry based methods for the enzymatic activity of BoNT and the anthrax lethal factor toxin.
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Affiliation(s)
- Suzanne R Kalb
- Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA.
| | - Anne E Boyer
- Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA.
| | - John R Barr
- Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA.
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10
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Rosen O, Feldberg L, Gura S, Zichel R. A new peptide substrate for enhanced botulinum neurotoxin type B detection by endopeptidase–liquid chromatography–tandem mass spectrometry/multiple reaction monitoring assay. Anal Biochem 2015; 473:7-10. [DOI: 10.1016/j.ab.2014.09.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 09/21/2014] [Accepted: 09/22/2014] [Indexed: 10/24/2022]
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11
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Björnstad K, Tevell Åberg A, Kalb SR, Wang D, Barr JR, Bondesson U, Hedeland M. Validation of the Endopep-MS method for qualitative detection of active botulinum neurotoxins in human and chicken serum. Anal Bioanal Chem 2014; 406:7149-61. [PMID: 25228079 DOI: 10.1007/s00216-014-8170-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 11/28/2022]
Abstract
Botulinum neurotoxins (BoNTs) are highly toxic proteases produced by anaerobic bacteria. Traditionally, a mouse bioassay (MBA) has been used for detection of BoNTs, but for a long time, laboratories have worked with alternative methods for their detection. One of the most promising in vitro methods is a combination of an enzymatic and mass spectrometric assay called Endopep-MS. However, no comprehensive validation of the method has been presented. The main purpose of this work was to perform a validation for the qualitative analysis of BoNT-A, B, C, C/D, D, D/C, and F in serum. The limit of detection (LOD), selectivity, precision, stability in matrix and solution, and correlation with the MBA were evaluated. The LOD was equal to or even better than that of the MBA for BoNT-A, B, D/C, E, and F. Furthermore, Endopep-MS was for the first time successfully used to differentiate between BoNT-C and D and their mosaics C/D and D/C by different combinations of antibodies and target peptides. In addition, sequential antibody capture was presented as a new way to multiplex the method when only a small sample volume is available. In the comparison with the MBA, all the samples analyzed were positive for BoNT-C/D with both methods. These results indicate that the Endopep-MS method is a valid alternative to the MBA as the gold standard for BoNT detection based on its sensitivity, selectivity, and speed and that it does not require experimental animals.
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Affiliation(s)
- Kristian Björnstad
- Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), 751 89, Uppsala, Sweden
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12
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Rosen O, Feldberg L, Gura S, Zichel R. Improved detection of botulinum type E by rational design of a new peptide substrate for endopeptidase-mass spectrometry assay. Anal Biochem 2014; 456:50-2. [PMID: 24721293 DOI: 10.1016/j.ab.2014.03.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 03/26/2014] [Accepted: 03/29/2014] [Indexed: 12/01/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the most toxic substances known to humans. Endopeptidase-mass spectrometry (Endopep-MS) is used as a specific and rapid in vitro assay to detect BoNTs. In this assay, immunocaptured toxin cleaves a serotype-specific peptide substrate, and the cleavage products are then detected by MS. To further improve the sensitivity of the assay, we report here the rational design of a new substrate peptide for the detection of botulinum neurotoxin type E (BoNT/E). Our strategy was based on previously reported structural interactions integrated with analysis method efficiency considerations. Integration of the newly designed substrate has led to a more than one order of magnitude increased sensitivity of the assay.
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Affiliation(s)
- Osnat Rosen
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Liron Feldberg
- Department of Analytical Chemistry, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Sigalit Gura
- Department of Analytical Chemistry, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Ran Zichel
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
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13
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Kalb SR, Baudys J, Smith TJ, Smith LA, Barr JR. Three enzymatically active neurotoxins of Clostridium botulinum strain Af84: BoNT/A2, /F4, and /F5. Anal Chem 2014; 86:3254-62. [PMID: 24605815 DOI: 10.1021/ac5001509] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Botulinum neurotoxins (BoNTs) are produced by various species of clostridia and are potent neurotoxins which cause the disease botulism, by cleaving proteins needed for successful nerve transmission. There are currently seven confirmed serotypes of BoNTs, labeled A-G, and toxin-producing clostridia typically only produce one serotype of BoNT. There are a few strains (bivalent strains) which are known to produce more than one serotype of BoNT, producing either both BoNT/A and /B, BoNT/A and /F, or BoNT/B and /F, designated as Ab, Ba, Af, or Bf. Recently, it was reported that Clostridium botulinum strain Af84 has three neurotoxin gene clusters: bont/A2, bont/F4, and bont/F5. This was the first report of a clostridial organism containing more than two neurotoxin gene clusters. Using a mass spectrometry based proteomics approach, we report here that all three neurotoxins, BoNT/A2, /F4, and /F5, are produced by C. botulinum Af84. Label free MS(E) quantification of the three toxins indicated that toxin composition is 88% BoNT/A2, 1% BoNT/F4, and 11% BoNT/F5. The enzymatic activity of all three neurotoxins was assessed by examining the enzymatic activity of the neurotoxins upon peptide substrates, which mimic the toxins' natural targets, and monitoring cleavage of the substrates by mass spectrometry. We determined that all three neurotoxins are enzymatically active. This is the first report of three enzymatically active neurotoxins produced in a single strain of Clostridium botulinum.
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Affiliation(s)
- Suzanne R Kalb
- Centers for Disease Control and Prevention , National Center for Environmental Health, Division of Laboratory Sciences, 4770 Buford Hwy, NE, Atlanta, Georgia 30341, United States
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14
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Comparison of the catalytic properties of the botulinum neurotoxin subtypes A1 and A5. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2722-8. [PMID: 24096023 DOI: 10.1016/j.bbapap.2013.09.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 09/12/2013] [Accepted: 09/16/2013] [Indexed: 11/22/2022]
Abstract
Clostridium botulinum neurotoxins (BoNTs) cause the life-threatening disease botulism through the inhibition of neurotransmitter release by cleaving essential SNARE proteins. There are seven serologically distinctive types of BoNTs and many subtypes within a serotype have been identified. BoNT/A5 is a recently discovered subtype of type A botulinum neurotoxin which possesses a very high degree of sequence similarity and identity to the well-studied A1 subtype. In the present study, we examined the endopeptidase activity of these two BoNT/A subtypes and our results revealed significant differences in substrate binding and cleavage efficiency between subtype A5 and A1. Distinctive hydrolysis efficiency was observed between the two toxins during cleavage of the native substrate SNAP-25 versus a shortened peptide mimic. N-terminal truncation studies demonstrated that a key region of the SNAP-25, including the amino acid residues at 151 through 154 located in the remote binding region of the substrate, contributed to the differential catalytic properties between A1 and A5. Elevated binding affinity of the peptide substrate resulted from including these important residues and enhanced BoNT/A5's hydrolysis efficiency. In addition, mutations of these amino acid residues affect the proteolytic performance of the two toxins in different ways. This study provides a better understanding of the biological activity of these toxins, their performance characteristics in the Endopep-MS assay to detect BoNT in clinical samples and foods, and is useful for the development of peptide substrates.
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Tevell Åberg A, Björnstad K, Hedeland M. Mass Spectrometric Detection of Protein-Based Toxins. Biosecur Bioterror 2013; 11 Suppl 1:S215-26. [DOI: 10.1089/bsp.2012.0072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Annica Tevell Åberg
- Annica Tevell Åberg, PhD, is a Senior Researcher; Kristian Björnstad, PhD, is a Senior Researcher; and Mikael Hedeland, PhD, is an Associate Professor and Deputy Head of Department; all at the Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), Uppsala, Sweden. Dr. Åberg and Dr. Hedeland are also affiliated with the Division of Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
| | - Kristian Björnstad
- Annica Tevell Åberg, PhD, is a Senior Researcher; Kristian Björnstad, PhD, is a Senior Researcher; and Mikael Hedeland, PhD, is an Associate Professor and Deputy Head of Department; all at the Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), Uppsala, Sweden. Dr. Åberg and Dr. Hedeland are also affiliated with the Division of Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
| | - Mikael Hedeland
- Annica Tevell Åberg, PhD, is a Senior Researcher; Kristian Björnstad, PhD, is a Senior Researcher; and Mikael Hedeland, PhD, is an Associate Professor and Deputy Head of Department; all at the Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), Uppsala, Sweden. Dr. Åberg and Dr. Hedeland are also affiliated with the Division of Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
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Luo S, Li T, Wang Q, Tian R, Liu H, Fang H, Chen F, Wang H. Development of a fusion protein SNVP as substrate for assaying multi-serotype botulinum neurotoxins. Anal Biochem 2013; 463:75-81. [PMID: 23851341 DOI: 10.1016/j.ab.2013.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 06/19/2013] [Accepted: 06/24/2013] [Indexed: 10/26/2022]
Abstract
The SNARE super family has three core members, namely SNAP-25, VAMP-2, and syntaxin. SNAP-25 is cleaved by botulinum toxins (BoNTs)/A, /C, and /E, whereas VAMP-2 is the substrate for proteolytic BoNTs/B, /D, /F, and /G. In this study, we constructed a hybrid gene encoding the fusion protein SNVP that encompasses SNAP-25 residues Met1 to Gly206 and VAMP-2 residues Met1 to Lys94. The hybrid gene was cloned in a prokaryotic vector carrying an N-terminal pelB signal sequence and overexpressed in Escherichia coli BL21(DE3) Rosetta. To easily purify the protein, 6× His double-affinity tags were designed as the linker and C terminus of the fusion protein. SNVP was purified to homogeneity by affinity chromatography on a HisTrap FF column and determined to be more than 97% pure by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. N-terminal sequencing of the purified protein showed that signal peptide was successfully removed. The fusion protein SNVP contained the protease cleavage sites of all seven serotypes of BoNTs. SNVP was also proved to be recognized and cleaved by the endopeptidase of BoNTs (BoNT/A-LC, BoNT/B-LC, BoNT/E-LC, and BoNT/G-LC). The novel fusion substrate SNVP exhibited high biological activity under the optimal conditions, suggesting its potential use as a reagent for BoNT assay.
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Affiliation(s)
- Sen Luo
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China; Department of Microbiology, An Hui Medical University, An Hui 230032, PR China
| | - Tao Li
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Qin Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Renmao Tian
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Hao Liu
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Huali Fang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Fanghong Chen
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Hui Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.
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Lautenschlager M, Maslanka SE, Paul PA, Kalb SR, Barr JR, Raphael BH. Recovery and detection of botulinum neurotoxins from a nonporous surface. J Microbiol Methods 2013; 92:278-80. [PMID: 23280253 DOI: 10.1016/j.mimet.2012.12.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 12/21/2012] [Accepted: 12/21/2012] [Indexed: 10/27/2022]
Abstract
We describe the adaptation of a sample recovery method for botulinum neurotoxins from stainless steel. Botulinum toxin was recovered from surfaces left to dry for up to 16 h and detected by either ELISA or EndoPep mass spectrometry methods. In addition, we demonstrate that this method can be used to evaluate the efficacy of surface decontamination procedures.
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