Tag Archives: RBA analysis

A Three Rs Perspective on the Mouse Bioassay in Routine Seafood Safety Testing for Algal Biotoxins — 1: Replacement

Ian Stewart and Catherine McLeod

Countries that have discontinued routine mouse bioassay testing
might gain a market advantage in domestic and export seafood
products over countries that continue to use the mouse test

The laboratory mouse has been the principal tool for routine testing of seafood — mainly shellfish — for the presence of hazardous concentrations of harmful algal toxins, since regulatory oversight of shellfish fisheries began in the 1920s. If undetected, as often is the case in unregulated fisheries, algal biotoxins can cause serious illness and death in people consuming contaminated shellfish and other seafood. A range of alternative testing techniques that do not rely on  the use of live mice are available to the seafood industry and food safety agencies. Some countries — notably Canada, New Zealand, the UK, and now Australia — have discontinued use of the mouse bioassay (MBA) for routine safety testing of shellfish to detect and measure paralytic shellfish toxins and the so-called lipophilic toxins (which includes diarrhetic shellfish toxins), but some other countries seek to maintain access to the mouse test.

Discussions and deliberations at an international level on the credentialing of alternative testing methods occur through the authority of the Codex Alimentarius Commission. Some are frustrated that  the Codex forum is the only conduit for implementing the protracted process by which the anachronistic and unethical MBA for routine shellfish safety testing can be consigned to history. Here, we present some strategies that seafood industries in countries which have discontinued use of the MBA might be able to apply, in order to secure market advantages over those in countries that seek to maintain the status quo. This, in turn, may put pressure on industries in countries that have as yet failed to adopt alternative replacement testing systems, to endorse and refine modern management systems. In a subsequent issue of PiLAS, we will discuss the MBA for routine testing of algal biotoxins in seafood from the perspectives of the other Three Rs initiatives: reduction and refinement.

Validated Alternative Assays
A wide range of chemical, biological and physical tests and assays have been investigated for the purpose of detecting and quantifying marine biotoxins in shellfish and other seafoods, as potential alternatives  to the MBA.1 Many of these alternative techniques have not progressed beyond the stage of research inquiry, but three liquid chromatographic methods 2-4 and a receptor binding assay (RBA)5 are now approved official methods for determining harmful concentrations of specific classes of marine algal toxins. Stewart and McLeod1 recently outlined some of the challenges and constraints in moving from the use of  the MBA for routine shellfish safety testing toward modern chemical or RBA analysis. Not least of these are requirements for sophisticated analytical instruments and high-level skills in analytical chemistry  needed to run these devices. However, analytical laboratories in many countries now have the capability to provide shellfish safety testing by using chemical methods, either under the aegis of government-managed  food safety programmes or as commercial service providers.

Worldwide Regulatory Standards
Requirements for shellfish biotoxin safety testing are determined by standards, guidelines and performance criteria prescribed by the Codex Alimentarius Commission, under the auspices of the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO); Codex is also charged with overseeing fair and equitable trade conventions across the food industry. Revision and refinement of performance criteria for biotoxin safety testing is effected by the Codex Committee on Fish and Fishery Products (CCFFP). At the most recent CCFFP meeting in Norway earlier this year, draft performance criteria for the determination of marine algal biotoxins in molluscs still allow agencies conducting shellfish safety testing to choose between chemical methods or a functional assay, which includes the MBA. The draft criteria6 state that: “The method selected should be chosen on the basis of practicability, and preference should be given to  methods which have applicability for routine use.” While it may be the case that this statement merely represents the status quo, in practice the ability of alternative chemical and functional tests to formally and globally supplant the MBA will likely rest on the accumulation, over years, of a data set demonstrating that alternative shellfish safety testing is indeed protective of public health to the same broad extent as is the MBA. In this regard, deliberations within the CCFFP continue to advance the ability of seafood industries and food safety agencies to adopt alternative replacement testing methods by developing  guidelines to address challenging technical issues pertinent to the implementation of non-animal based methods, such as toxicity equivalence factors and other relevant performance criteria. 6
This is not to suggest, however, that expert opinion is currently of one voice on the need to end the availability of the MBA for shellfish safety testing. National delegates at CCFFP meetings and working groups are divided on the issue. Stewart and McLeod1 have noted some of the countries that have taken a leadership role in ending use of the MBA for routine shellfish safety testing, particularly Canada, New Zealand and the UK. Ireland was another early adopter of chemical- only testing for routine shellfish monitoring. Dissenting opinion in part centres on the claim that removing access to the MBA would represent an unfair trade advantage in favour of developed countries that have the resources to support the infrastructure and skills required to adopt and run chemical testing regimens. This position in favour of maintaining the status quo was expounded in a submission by the Philippines to the 2012 CCFFP meeting, held in Bali, Indonesia. The Philippines supported the position of the USA and Chile that access to the MBA for routine biotoxin monitoring should continue. The Philippines submission7 notes that: “For almost 30 years now, MBA is continuously protecting millions of Filipinos dependent on shellfish as the cheapest source of protein.” Interestingly, the Philippines complements its use of the MBA for shellfish safety testing with a multi-analogue HPLC technique, although this is only performed at a single centre in Manila. However, the MBA itself is performed at several locations across the archipelago.7

Trade Barriers: Who Benefits?
We suggest here that the claim for continuing access to the MBA as a routine biotoxin test for seafood safety, because of the potential trade barriers presented by the skills and infrastructure requirements  of early 21st century chemical testing, deserves closer scrutiny. We do not dispute the suggestion that the skills and equipment demands of modern chemical testing are not inconsiderable. However, the reciprocal assumption that the MBA represents a lowcost option is not a given. While the disapprobation of some scientists and technicians tasked with conducting MBA shellfish safety testing may have had some influence on expert opinion on this matter — author McLeod being one such scientist, who found the assignment objectionable — it is likely that economic  considerations have been a more significant determinant of change in countries that have or are in the process of discontinuing use of the mouse test. The experience in Australia may serve to illustrate  this point.

Scientific tests on live mammals in Australia — including the MBA for routine shellfish safety testing — must be approved and overseen by a properly constituted ethics committee, and Australian state governments must approve and licence facilities in which  such testing is conducted (see  http://www.animalethics.org.au/legislation). Laboratories that conduct scientific testing and research are required to apply rigorous standards of hygiene and husbandry, typically involving buildings that allow for the control of environmental variables such as temperature,  humidity and lighting. In practice, this usually translates to use of specific pathogen-free animals in facilities staffed by appropriately trained and supervised workers. And the operating costs for such facilities are not insubstantial — costs which are factored into their pricing schedule for service provision. The price per sample for paralytic shellfish toxins by MBA testing at the sole Australian laboratory with ethical clearance to perform the MBA for seafood safety was A$390 (including sample preparation); the charges for qualitative screening (detect/nil detect result provided) and confirmatory testing (quantitative result provided) by liquid chromatography with fluorescence detection methods from the Australian provider are A$85 and A$370, respectively. So the MBA for routine biotoxin monitoring in shellfish is not considered to be a low-cost test in Australia. The  compliance cost to Australia’s shellfish industry of routine biotoxin monitoring has been a major incentive for changing to a chemical testing programme. An additional motivating factor for the shellfish  industry and regulators in Australia was the requirement for a more specific test method that returns results only for the regulated marine toxins and excludes other compounds, such as the cyclic imines, which are not subject to food safety oversight and can cause false-positive results in the MBA. A single commercial analytical laboratory in Australia was awarded the tender, after a committee comprising seafood industry representatives and government food safety agencies considered various options for delivery of this service, including the use of providers in each state, a single national provider, and the use of government, university and private sector laboratories. Proponents of continuing use of the MBA for routine seafood safety testing assert that restricting access to the test would represent an unfair trade advantage in favour of developed countries with resources to support  the skills, equipment and infrastructure requirements of liquid chromatography-based analysis. We suggest that these claims are spurious. We propose, considering the extent that the MBA is a low-cost technique in the hands of agencies in some countries that continue to  use the test, that standards of mouse colony breeding and maintenance, husbandry, disease prevention and ethical oversight, must, wholly or in part, be of a lower standard than that seen in the example outlined above of a tightly-regulated dominion like Australia. Therefore, we suggest that countries that conduct the MBA on the cheap, so to speak, are simultaneously cutting corners on animal welfare and potentially experiencing an unfair trade advantage in so doing.

Promoting the ‘Ethical Choice’ to Consumers
An overwhelming majority of shellfish consumers are likely to be unaware that batch and fishery testing, by any method, for algal biotoxin safety is conducted as a matter of routine. Yet there may be a case for the seafood industry in countries that have relinquished  routine MBA testing for algal toxins (e.g. Australia, Canada, Ireland, New Zealand, the UK and some European nations) to take the initiative and actively promote their transition to an ethically unencumbered chemical testing regimen, in order to secure an international market advantage.

Video footage of a bored technician — peering, with stopwatch or electronic timer in hand, at a suffering and terrified mouse in order to ascertain when it has drawn its final asphyxiated breath — will not play well on prime-time television. If and when animal welfare activists decide to campaign on this topic, considerable  economic disruption may ensue.

The fallout from such a campaign should, of course, be visited disproportionately on seafood products from countries and industries that continue to rely on the MBA, but the  potential for some global industry-wide disruption might be realised in the wake of consumer ignorance about the facts of routine monitoring programmes, and the important differences between the MBA and alternative testing methodologies.

A pre-emptive approach by the seafood industry to educate consumers about food safety monitoring programmes could deliver appreciable benefits both to industry and its customers. The trends are for increasing consumer concern and awareness of food safety, particularly in well-educated and higher income  demographics.8 The message of routine monitoring for marine algal toxins should not, in principle, be a difficult sell for the seafood industry, as there is a long history of product safety and public  health protection from monitored fisheries, attributable to both the MBA — since monitoring began in the 1920s in the USA — and more recently, from fisheries that have adopted replacement alternative testing methods.1 Marketing strategies to better inform seafood consumers about routine monitoring programmes for algal biotoxins could potentially realise the dual benefits of a) embedding the food safety message that products from monitored fisheries have an excellent consumer protection record, and b) emphasising that products from countries that have discontinued the use of the MBA for routine  biotoxin safety testing are not subject to unfavourable animal welfare considerations.

In the event that the routine MBA for detection of  algal toxins in shellfish and other seafood becomes the focus of a future public awareness campaign by animal welfare proponent organisations, a pre-emptive information drive by the seafood industry and food safety agencies in countries that have replaced the MBA with alternative testing regimens should effectively insulate local industries against the economic disruption to be expected as a result of such a campaign. The appropriate targets of an animal welfare operation directed at the seafood industry would be fisheries in countries that continue to use the MBA routinely and/or advocate its continued availability. Countries that have discontinued routine  MBA testing might well gain a market advantage in domestic and export seafood products, at the expense of imports from countries that continue to use the mouse test.

Dr Catherine McLeod
Seafood Safety Assessment Ltd
Isle of Skye IV44 8RG

Author for correspondence:
Dr Ian Stewart
The University of Queensland
National Research Centre for Environmental
Coopers Plains
QLD 4108
E-mail: i.stewart@uq.edu.au

1 Stewart, I. & McLeod, C. (2014). The laboratory mouse in routine food safety testing for marine algal biotoxins and harmful algal bloom toxin research: Past, present and future. Journal of AOAC International 97, 356–372.
2 AOAC International (2012). Method 2005.06 In Official Methods of Analysis. Gaithersburg, MD, USA: AOAC
International. Available at: http://www.eoma.aoac.org/ (Accessed 25.10.14).
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International. Available at: http://www.eoma.aoac.org/ (Accessed 25.10.14).
4 EU-RL-MB & AESAN (2011). EU-Harmonised Standard Operating Procedure for Determination of Lipophilic Marine Biotoxins in Molluscs by LC-MS/MS, 31pp. Vigo, Spain: European Union Reference Laboratory for Marine Biotoxins & Agencia Española de Seguridad Alimentaria y Nutrición.
5 AOAC International (2012). Method 2011.27 In Official Methods of Analysis. Gaithersburg, MD, USA: AOAC
International. Available at: http://www.eoma.aoac. org/ (Accessed 25.10.14).
6 Codex Alimentarius Commission (2014). Joint FAO/ WHO Food Standards Programme: Codex Alimentarius
Commission. Report of the Thirty-third Session of the Codex Committee on Fish and Fishery Products,
Bergen, Norway, 17–21 February 2014, vi + 64pp. Rome, Italy: Codex Alimentarius Commission.
7 Codex Alimentarius Commission (2014). Joint FAO/ WHO Food Standards Programme: Codex Committee
on Fish and Fishery Products, 32nd Session, Bali, Indonesia, 8pp. Rome, Italy: Codex Alimentarius
8 Dosman, D.M., Adamowicz, W.L. & Hrudey, S.E. (2001). Socioeconomic determinants of health- and food safety-related risk perceptions. Risk Analysis 21, 307–317. P56