Bioassay and Related Methods

Jay, James M.

doi:10.1007/978-1-4615-4427-2_12

Cited by 3 publications

(1 citation statement)

References 45 publications

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“…Various techniques have been used to detect ETX, including mass spectrometry (MS) (4,5), enzyme-linked immunosorbent assay (ELISA) (2,6), toxin-susceptible cell cultures (7,8), polymerase chain reaction (PCR) (9,10), and enzyme immunoassay (EIA) (11,12). Mass spectrometry is a novel method that overcomes the cross-reactivity issues seen in antibody-based assays.…”

Section: Introductionmentioning

confidence: 99%

Screening and Identification of DNA Nanostructure Aptamer Using the SELEX Method for ‎Detection of Epsilon Toxin

Shafiei,

Mahmoodzadeh Hosseini,

Amani

et al. 2023

Iran J Pharm Res

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Background: Epsilon toxin (ETX), produced by Clostridium perfringens, is one of the most ‎potent toxins ‎known, with a lethal potency approaching that of botulinum neurotoxins. Epsilon toxin ‎is responsible ‎for enteritis. Therefore, the development of rapid and simple methods to ‎detect ETX ‎is imperative. Aptamers are single-stranded oligonucleotides that can bind ‎tightly to specific ‎target molecules with an affinity comparable to that of monoclonal antibodies (mAbs). ‎DNA aptamers ‎can serve as tools for the molecular identification of organisms, such as ‎pathogen subspecies.‎ Objectives: This study aimed to isolate high-affinity single-stranded DNA (ssDNA) ‎aptamers against ETX.‎ Methods: This study identified aptamers using the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method, enzyme-linked apta-sorbent assay (ELASA), and surface plasmon resonance (SPR) to determine ‎the affinity and ‎specificity of the newly obtained aptamers targeting ETX. ‎ Results: Several aptamers obtained through the ‎SELEX process were studied. Among them, 2 aptamers, ETX clone 3 (ETX3; dissociation constant [Kd] = 8.4 ± 2.4E-9M) ‎and ETX11 (Kd = 6.3 ± 1.3E-9M) had favorable specificity for ETX. The limits of detection ‎were 0.21 and 0.08 μg/mL for ETX3 and ETX11, respectively.‎ Conclusions: The discovered aptamers can be used in various aptamer-based rapid diagnostic tests for the detection of ETX.

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Section: Introductionmentioning

confidence: 99%

Screening and Identification of DNA Nanostructure Aptamer Using the SELEX Method for ‎Detection of Epsilon Toxin

Shafiei,

Mahmoodzadeh Hosseini,

Amani

et al. 2023

Iran J Pharm Res

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Rapid and Sensitive Nano-Immunosensors for Botulinum

Cheng

Chuang

2019

ACS Sens.

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Botulinum is a deadly bacterial toxin that causes neuroparalytic disease. However, appropriate tools to detect trace toxic proteins are scarce. This study presents a bead-based diffusometric technique for the rapid, simple, and quantitative detection of biological toxins. Functionalized particles called nano-immunosensors were fabricated by forming sandwiched immunocomplexes comprising Au nanoparticles (AuNPs), toxic proteins, and antibodies on fluorescent probe particles. Particle diffusivity tended to decline with increasing concentration of the target proteins. Calibration curves of purified botulinum toxins (0.01−500 ng/mL) were obtained from whole milk and bovine serum, and results suggested that measurement was independent of the background matrix. The activity of botulinum toxin was evaluated by coating synaptosomal-associated protein 25 (SNAP-25) on fluorescent probe particles. AuNP-conjugated antibodies attached to the probe particles when SNAP-25 proteins were cleaved by active botulinum. Thus, toxicity could be detected from slight changes in diffusivity. A short measurement time of 2 min and a limit of detection of 10 pg/mL were achieved. The nano-immunosensors demonstrated rapid biosensing capability and met the demands of onsite screening for food safety, medical instrument hygiene, and cosmetic surgery products.

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Detection of toxins involved in foodborne diseases caused by Gram‐positive bacteria

Rajković

Jovanović

Monteiro

et al. 2020

Comp Rev Food Sci Food Safe

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Bacterial toxins are food safety hazards causing about 10% of all reported foodborne outbreaks in Europe. Pertinent to Gram‐positive pathogens, the most relevant toxins are emetic toxin and diarrheal enterotoxins of Bacillus cereus, neurotoxins of Clostridium botulinum, enterotoxin of Clostridium perfringens, and a family of enterotoxins produced by Staphylococcus aureus and some other staphylococci. These toxins are the most important virulence factors of respective foodborne pathogens and a primary cause of the related foodborne diseases. They are proteins or peptides that differ from each other in their size, structure, toxicity, toxicological end points, solubility, and stability, types of food matrix to which they are mostly related to. These differences influence the characteristics of required detection methods. Therefore, detection of these toxins in food samples, or detection of toxin production capacity in the bacterial isolate, remains one of the cornerstones of microbial food analysis and an essential tool in understanding the relevant properties of these toxins. Advanced research has led into new insights of the incidence of toxins, mechanisms of their production, their physicochemical properties, and their toxicological mode of action and dose‐response profile. This review focuses on biological, immunological, mass spectrometry, and molecular assays as the most commonly used detection and quantification methods for toxins of B. cereus, C. botulinum, C. perfringens, and S. aureus. Gathered and analyzed information provides a comprehensive blueprint of the existing knowledge on the principles of these assays, their application in food safety, limits of detection and quantification, matrices in which they are applicable, and type of information they provide to the user.

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Bioassay and Related Methods

Cited by 3 publications

References 45 publications

Screening and Identification of DNA Nanostructure Aptamer Using the SELEX Method for ‎Detection of Epsilon Toxin

Screening and Identification of DNA Nanostructure Aptamer Using the SELEX Method for ‎Detection of Epsilon Toxin

Rapid and Sensitive Nano-Immunosensors for Botulinum

Detection of toxins involved in foodborne diseases caused by Gram‐positive bacteria

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