Histamine risk in fishery products

Histamine poisoning is the first cause of fish-related foodborne infection in France. It is thermostable and is produced at positive temperatures in a wide variety of pelagic fish (tuna, swordfish, mackerel, sardine, herring, or anchovy) by decarboxylation of free histidine under the action of a bacterial enzyme, histidine decarboxylase (HDC). The implementation of hygiene measures helps limit bacterial contamination after fish capture, and thus reduces the risks of contamination by histidine decarboxylase producing bacteria. The cold chain also plays an essential role to reduce the production of histamine, or even inhibit it in the case of frozen fish.L'histamine est la première cause de toxi-infections alimentaires liées à la consommation de poisson en France. Elle est thermostable et se forme aux températures positives, chez un grand nombre d'espèces de poissons pélagiques (comme le thon, l'espadon, le maquereau, la sardine, le hareng, ou l'anchois) par décarboxylation de l'histidine libre sous l'action d'une enzyme d'origine bactérienne: l'histidine décarboxylase (HDC). L'application des règles d'hygiène permet de limiter les contaminations bactériennes après la capture et réduit ainsi les risques de contamination par des bactéries produisant l'histidine décarboxylase. La mise en oeuvre du froid est tout aussi essentielle et permet de limiter la production d'histamine voire de l'arrêter si le poisson est congelé

Development of an SPME-GC-MS method for the specific quantification of dimethylamine and trimethylamine: use of a new ratio for the freshness monitoring of cod fillets

International audienceBACKGROUND: Fish is a highly perishable food, so it is important to be able to estimate its freshness to ensure optimum quality for consumers. The present study describes the development of an SPME‐GC‐MS technique capable of quantifying both trimethylamine (TMA) and dimethylamine (DMA), components of what has been defined as partial volatile basic nitrogen (PVB‐N). This method was used, together with other reference methods, to monitor the storage of cod fillets (Gadus morhua) conserved under melting ice.RESULTS: Careful optimisation enabled definition of the best parameters for extracting and separating targeted amines and an internal standard. The study of cod spoilage by sensory analysis and TVB‐N assay led to the conclusion that the shelf‐life of cod fillet was between 6 and 7 days. Throughout the study, TMA and DMA were specifically quantified by SPME‐GC‐MS; the first was found to be highly correlated with the values returned by steam distillation assays. Neither TMA‐N nor DMA‐N were able to successfully characterise the decrease in early freshness, unlike dimethylamine/trimethylamine ratio (DTR), whose evolution is closely related to the results of sensory analysis until the stage where fillets need to be rejected.CONCLUSION: DTR was proposed as a reliable indicator for the early decrease of freshness until fish rejection

Long-term outcomes of CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) in a consecutive series of 12 patients.

BACKGROUND: Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a central nervous system inflammatory disease. OBJECTIVE: To describe the disease course of CLIPPERS. DESIGN: A nationwide study was implemented to collect clinical, magnetic resonance imaging, cerebrospinal fluid, and brain biopsy specimen characteristics of patients with CLIPPERS. SETTING: Academic research. PATIENTS: Twelve patients with CLIPPERS. MAIN OUTCOME MEASURES: The therapeutic management of CLIPPERS was evaluated. RESULTS: Among 12 patients, 42 relapses were analyzed. Relapses lasted a mean duration of 2.5 months, manifested frequent cerebellar ataxia and diplopia, and were associated with a mean Expanded Disability Status Scale (EDSS) score of 4. Besides typical findings of CLIPPERS, magnetic resonance imaging showed brainstem mass effect in 5 patients, extensive myelitis in 3 patients, and closed ring enhancement in 1 patient. Inconstant oligoclonal bands were found on cerebrospinal fluid investigation in 4 patients, with an increased T-cell ratio of CD4 to CD8. Among 7 available brain biopsy specimens, staining was positive for perivascular CD4 T lymphocytes in 5 samples. Thirty-eight of 42 relapses were treated with pulse corticosteroid therapy, which led to improvement, with a mean residual EDSS score of 1.9 (range, 0-7). In 1 patient with untreated relapses, scores on the EDSS progressively increased to a score of 10 at death. Among 5 patients without long-term corticosteroid therapy, the mean annualized relapse rate was 0.5 (range, 0.25-2.8). Among 7 patients taking oral corticosteroids, no relapses occurred in those whose daily dose was 20 mg or higher. No progressive course of CLIPPERS was observed. Four patients with a final EDSS score of 4 or higher had experienced previous severe relapses (EDSS score, ≥5) and brainstem and spinal cord atrophy. CONCLUSIONS: CLIPPERS is a relapsing-remitting disorder without progressive forms. Long-term disability is correlated with the severity of previous relapses. Further studies are needed to confirm that prolonged corticosteroid therapy prevents further relapses.journal article2012 Julimporte

Current frontiers and recommendations for the study of microplastics in seafood

International audienceFor seventy years, mass plastic production and waste mismanagement have resulted in huge pollution of the environment, including the marine environment. The first mention of seafood contaminated by microplastics was recorded in the seventies, and to date numerous studies have been carried out on shellfish, fish and crustaceans. Based on an ad hoc corpus, the current review aims to report on the numerous practices and methodologies described so far. By examining multiple aspects including problems related to the definition of the term microplastic, contamination at the laboratory scale, sampling and isolation, and quantification and identification, the aim was to point out current limitations and the needs to improve and harmonise practices for future studies on microplastics in seafood. A final part is devoted to the minimum information for publication of microplastics studies (MIMS). Based on the aspects discussed, MIMS act as a starting point for harmonisation of analyses

Think positive: Proposal of a simple method to create reference materials in the frame of microplastics research

In the context of the harmonization of methodologies employed to isolate and count microplastics in samples or to organize ring trials tests, the use of reference materials, i.e. samples with controlled amount of particles is required. The method proposed here uses transparent, sealed capsules containing in-house generated microplastics as a convenient way to generate microplastic reference materials. This method is a simple approach for adding particles to samples without risk of loss during particle extraction or transporting/handling. • Low-cost and easy-to-use preparation of heterogeneous mix of microplastic reference particles • Possibility to control microplastic size, shape, and polymeric composition • Applicable to many protocols and wide range of applications on water, sediments and biota

Relevance of matrix effect in determination of biogenic amines in plaice (Pleuronectes platessa) and whiting (Merlangus merlangus)

International audienc

Use of biogenic amines to evaluate spoilage in plaice (Pleuronectes platessa) and whiting (Merlangus merlangus)

International audienc

Répartition verticale et variabilité saisonnière de la contamination microplastiques dans la colonne d’eau d’une rivière en utilisant une méthode d’échantillonnage innovante

National audienc

Répartition verticale et variabilité saisonnière de la contamination microplastiques dans la colonne d’eau d’une rivière en utilisant une méthode d’échantillonnage innovante

National audienceDans le cadre de cette étude, la contamination en microplastiques a été évaluée dans une rivière à la fois en surface (0-25cm) et en subsurface (25-50cm). La partie la plus profonde de la colonne d’eau (10 derniers cm) a également été échantillonnée ainsi les sédiments. Trois campagnes d’échantillonnage ont été menées lors de différentes conditions météorologiques : durant une forte pluie au printemps, après une forte pluie en automne et lors d’une période sèche en hiver. Les résultats montrent que les eaux de subsurface contiennent autant de particules que les eaux de surface, quelles que soient les conditions environnementales.Des concentrations en particules 3 à 11 fois supérieures ont été retrouvées lors des fortes pluies au printemps comparées aux autres campagnes d’échantillonnage dans tous les compartiments étudiés dans la colonne d’eau. Tous compartiments confondus, le type de particules observé est impacté par les conditions météorologiques avec 86% à 96% de fibres parmi les particules échantillonnées en hiver, comparé aux autres campagnes au printemps et en automne où les fibres représentent respectivement 31% et 75%.Lors de cette étude 73,5% des particules analysées sont des polymères qui ont une densité théorique inférieure à 1 dans les échantillons de surface et subsurface, alors que cette proportion tombe à 40,8% pour les échantillons de fond et de sédiments ce qui indique une répartition des particules selon leur densité dans la colonne d’eau.Cette étude souligne l’importance de prendre en compte la subsurface ainsi que les variations saisonnières pour évaluer les types et niveaux de contamination microplastiques dans les environnements fluviaux