A seafood risk tool for assessing and mitigating chemical and pathogen hazards in the aquaculture supply chain.

Intricate links between aquatic animals and their environment expose them to chemical and pathogenic hazards, which can disrupt seafood supply. Here we outline a risk schema for assessing potential impacts of chemical and microbial hazards on discrete subsectors of aquaculture-and control measures that may protect supply. As national governments develop strategies to achieve volumetric expansion in seafood production from aquaculture to meet increasing demand, we propose an urgent need for simultaneous focus on controlling those hazards that limit its production, harvesting, processing, trade and safe consumption. Policies aligning national and international water quality control measures for minimizing interaction with, and impact of, hazards on seafood supply will be critical as consumers increasingly rely on the aquaculture sector to supply safe, nutritious and healthy diets.

Sustainable aquaculture through the One Health lens.

Aquaculture is predicted to supply the majority of aquatic dietary protein by 2050. For aquaculture to deliver significantly enhanced volumes of food in a sustainable manner, appropriate account needs to be taken of its impacts on environmental integrity, farmed organism health and welfare, and human health. Here, we explore increased aquaculture production through the One Health lens and define a set of success metrics - underpinned by evidence, policy and legislation - that must be embedded into aquaculture sustainability. We provide a framework for defining, monitoring and averting potential negative impacts of enhanced production - and consider interactions with land-based food systems. These metrics will inform national and international science and policy strategies to support improved aquatic food system design.

A pan-European ring trial to validate an International Standard for detection of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus in seafoods.

Globally, vibrios represent an important and well-established group of bacterial foodborne pathogens. The European Commission (EC) mandated the Comite de European Normalisation (CEN) to undertake work to provide validation data for 15 methods in microbiology to support EC legislation. As part of this mandated work programme, merging of ISO/TS 21872-1:2007, which specifies a horizontal method for the detection of V. parahaemolyticus and V. cholerae, and ISO/TS 21872-2:2007, a similar horizontal method for the detection of potentially pathogenic vibrios other than V. cholerae and V. parahaemolyticus was proposed. Both parts of ISO/TS 21872 utilized classical culture-based isolation techniques coupled with biochemical confirmation steps. The work also considered simplification of the biochemical confirmation steps. In addition, because of advances in molecular based methods for identification of human pathogenic Vibrio spp. classical and real-time PCR options were also included within the scope of the validation. These considerations formed the basis of a multi-laboratory validation study with the aim of improving the precision of this ISO technical specification and providing a single ISO standard method to enable detection of these important foodborne Vibrio spp.. To achieve this aim, an international validation study involving 13 laboratories from 9 countries in Europe was conducted in 2013. The results of this validation have enabled integration of the two existing technical specifications targeting the detection of the major foodborne Vibrio spp., simplification of the suite of recommended biochemical identification tests and the introduction of molecular procedures that provide both species level identification and discrimination of putatively pathogenic strains of V. parahaemolyticus by the determination of the presence of theromostable direct and direct related haemolysins. The method performance characteristics generated in this have been included in revised international standard, ISO 21872:2017, published in July 2017.

The development of LENTICULES™ as reference materials for noroviruses.

AIMS: To investigate the potential for LENTICULES™ to act as reference materials (RMs) for noroviruses (NoV) [genogroups I (GI) and II (GII)] by determining their homogeneity and stability characteristics. METHODS AND RESULTS: NoV used in this study originated from human faecal material, screened for the absence of other faecally transmitted pathogens. The norovirus strains present in the faecal material were characterized by sequencing, and samples containing GI and GII strains representative of genotypes commonly circulating in the community were selected. RMs were produced utilizing modified lenticulating technology. A batch comprising 500 LENTICULES™ containing both norovirus genogroups was produced according to ISO Guide 34. The batch was tested and quantified using an ISO 17025 accredited quantitative real-time RT-PCR assay. Sufficient homogeneity was established using procedures described by Fearn and Thompson (2010), while stability at less than -15°C and ambient temperature (17-22°C) was assessed over 52 weeks and 7 days, respectively. CONCLUSIONS: Lenticulation was shown to be an effective means of preservation of detectable NoV. LENTICULES™ were sufficiently homogeneous and stable throughout medium-term frozen and short-term storage at room temperature to serve as RMs. Virus LENTICULES™ have the advantages of being easy to manipulate, provide assigned values and do not require the manipulation of high titre clinical material. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study show that norovirus LENTICULES™ can be used as stable RMs for quantitative real-time RT-PCR assays. They can be utilized as in-run positive extraction controls and potentially for method calibration and to enable more easy comparison of data generated by the variety of differing norovirus determination methods that have emerged in recent years. LENTICULES™ have the potential to provide essential elements of laboratory quality assurance systems for laboratories implementing these new methods for virus testing in foodstuffs and for those running routine analyses.