Current Trends and Challenges for Rapid SMART Diagnostics at Point-of-Site Testing for Marine Toxins

Abstract

In the past twenty years marine biotoxin analysis in routine regulatory monitoring has advanced significantly in Europe (EU) and other regions from the use of the mouse bioassay (MBA) towards the high-end analytical techniques such as high-performance liquid chromatography (HPLC) with tandem mass spectrometry (MS). Previously, acceptance of these advanced methods, in progressing away from the MBA, was hindered by a lack of commercial certified analytical standards for method development and validation. This has now been addressed whereby the availability of a wide range of analytical standards from several companies in the EU, North America and Asia has enhanced the development and validation of methods to the required regulatory standards. However, the cost of the high-end analytical equipment, lengthy procedures and the need for qualified personnel to perform analysis can still be a challenge for routine monitoring laboratories. In developing regions, aquaculture production is increasing and alternative inexpensive Sensitive, Measurable, Accurate and Real-Time (SMART) rapid point-of-site testing (POST) methods suitable for novice end users that can be validated and internationally accepted remain an objective for both regulators and the industry. The range of commercial testing kits on the market for marine toxin analysis remains limited and even more so those meeting the requirements for use in regulatory control. Individual assays include enzyme-linked immunosorbent assays (ELISA) and lateral flow membrane-based immunoassays (LFIA) for EU-regulated toxins, such as okadaic acid (OA) and dinophysistoxins (DTXs), saxitoxin (STX) and its analogues and domoic acid (DA) in the form of three separate tests offering varying costs and benefits for the industry. It can be observed from the literature that not only are developments and improvements ongoing for these assays, but there are also novel assays being developed using upcoming state-of-the-art biosensor technology. This review focuses on both currently available methods and recent advances in innovative methods for marine biotoxin testing and the end-user practicalities that need to be observed. Furthermore, it highlights trends that are influencing assay developments such as multiplexing capabilities and rapid POST, indicating potential detection methods that will shape the future market.

Multiplex Lateral Flow Assay and the Sample Preparation Method for the Simultaneous Detection of Three Marine Toxins

“… 11 , 23 , 24 The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance. 2 To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers. DSP and PSP kits cannot unequivocally measure the levels of each congener of regulatory interest, due to variations in the specificity of the antibodies for different congeners, and could only be considered as semi-quantitative.…”

“…Although manufacturers of the monoplex Neogen ASP, DSP, and PSP kits recommend their use as qualitative “yes/no” assays, the AccuScan PRO reader they are used with can provide a numerical result, which has been recommended to be made available to the end user, as a useful tool for determining toxin amounts. ,, The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance . To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers.…”

Multiplex Lateral Flow Assay and the Sample Preparation Method for the Simultaneous Detection of Three Marine Toxins

“… 11 , 23 , 24 The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance. 2 To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers. DSP and PSP kits cannot unequivocally measure the levels of each congener of regulatory interest, due to variations in the specificity of the antibodies for different congeners, and could only be considered as semi-quantitative.…”

“…Although manufacturers of the monoplex Neogen ASP, DSP, and PSP kits recommend their use as qualitative “yes/no” assays, the AccuScan PRO reader they are used with can provide a numerical result, which has been recommended to be made available to the end user, as a useful tool for determining toxin amounts. ,, The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance . To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers.…”

Development of an Automated Cell-Based Assay for the Detection of the Functional Activity of Saxitoxin

“…However these methods are limited in terms of confirming toxicity in a biological system. Methods which could provide further information about toxicity include the MBA, RBA and APC [ 10 , 11 , 15 ]. The MBA can provide information on the toxicity of a sample This technique has its disadvantages: the robustness of the assay, strain of the mouse, and pH of the extract have been shown to affect the result.…”

Biosensor for the Detection of Cyanobacterial Toxin Microcystin-LR

“…The list of currently available point-on-site marine toxin end-product testing technologies is provided in ref. [28].…”

Multiplex Lateral Flow Assay and the Sample Preparation Method for the Simultaneous Detection of Three Marine Toxins

“… 11 , 23 , 24 The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance. 2 To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers. DSP and PSP kits cannot unequivocally measure the levels of each congener of regulatory interest, due to variations in the specificity of the antibodies for different congeners, and could only be considered as semi-quantitative.…”

“…Although manufacturers of the monoplex Neogen ASP, DSP, and PSP kits recommend their use as qualitative “yes/no” assays, the AccuScan PRO reader they are used with can provide a numerical result, which has been recommended to be made available to the end user, as a useful tool for determining toxin amounts. ,, The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance . To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers.…”

Development of an Automated Cell-Based Assay for the Detection of the Functional Activity of Saxitoxin

“…However these methods are limited in terms of confirming toxicity in a biological system. Methods which could provide further information about toxicity include the MBA, RBA and APC [ 10 , 11 , 15 ]. The MBA can provide information on the toxicity of a sample This technique has its disadvantages: the robustness of the assay, strain of the mouse, and pH of the extract have been shown to affect the result.…”

Biosensor for the Detection of Cyanobacterial Toxin Microcystin-LR

“…The list of currently available point-on-site marine toxin end-product testing technologies is provided in ref. [28].…”

Multiplex Lateral Flow Assay and the Sample Preparation Method for the Simultaneous Detection of Three Marine Toxins

“… 11 , 23 , 24 The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance. 2 To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers. DSP and PSP kits cannot unequivocally measure the levels of each congener of regulatory interest, due to variations in the specificity of the antibodies for different congeners, and could only be considered as semi-quantitative.…”

“…Although manufacturers of the monoplex Neogen ASP, DSP, and PSP kits recommend their use as qualitative “yes/no” assays, the AccuScan PRO reader they are used with can provide a numerical result, which has been recommended to be made available to the end user, as a useful tool for determining toxin amounts. ,, The occurrence of toxins remains difficult to predict owing to the complex dynamics that cause algal bloom development, their heterogeneous distribution, and rapid appearance . To provide sufficient warning to allow for changes in harvest patterns and the relocation of large quantities of shellfish, a quantitative or semi-quantitative approach would be of great use to shellfish farmers.…”

Development of an Automated Cell-Based Assay for the Detection of the Functional Activity of Saxitoxin

“…However these methods are limited in terms of confirming toxicity in a biological system. Methods which could provide further information about toxicity include the MBA, RBA and APC [ 10 , 11 , 15 ]. The MBA can provide information on the toxicity of a sample This technique has its disadvantages: the robustness of the assay, strain of the mouse, and pH of the extract have been shown to affect the result.…”

Biosensor for the Detection of Cyanobacterial Toxin Microcystin-LR

“…The list of currently available point-on-site marine toxin end-product testing technologies is provided in ref. [28].…”