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Astronauts are spending longer periods locked up in ships or stations for scientific and exploration spatial missions. The International Space Station (ISS) has been inhabited continuously for more than 20 years and the duration of space stays by crews could lengthen with the objectives of human presence on the moon and Mars. If the environment of these space habitats is designed for the comfort of astronauts, it is also conducive to other forms of life such as embarked microorganisms. The latter, most often associated with surfaces in the form of biofilm, have been implicated in significant degradation of the functionality of pieces of equipment in space habitats. The most recent research suggests that microgravity could increase the persistence, resistance and virulence of pathogenic microorganisms detected in these communities, endangering the health of astronauts and potentially jeopardizing long-duration manned missions. In this review, we describe the mechanisms and dynamics of installation and propagation of these microbial communities associated with surfaces (spatial migration), as well as long-term processes of adaptation and evolution in these extreme environments (phenotypic and genetic migration), with special reference to human health. We also discuss the means of control envisaged to allow a lasting cohabitation between these vibrant microscopic passengers and the astronauts., Biofilm, 5, ISSN:2590-2075

The comet assay is a versatile method to detect nuclear DNA damage in individual eukaryotic cells, from yeast to human. The types of damage detected encompass DNA strand breaks and alkali-labile sites (e.g., apurinic/apyrimidinic sites), alkylated and oxidized nucleobases, DNA-DNA crosslinks, UV-induced cyclobutane pyrimidine dimers and some chemically induced DNA adducts. Depending on the specimen type, there are important modifications to the comet assay protocol to avoid the formation of additional DNA damage during the processing of samples and to ensure sufficient sensitivity to detect differences in damage levels between sample groups. Various applications of the comet assay have been validated by research groups in academia, industry and regulatory agencies, and its strengths are highlighted by the adoption of the comet assay as an in vivo test for genotoxicity in animal organs by the Organisation for Economic Co-operation and Development. The present document includes a series of consensus protocols that describe the application of the comet assay to a wide variety of cell types, species and types of DNA damage, thereby demonstrating its versatility.The comet assay is commonly used to assess DNA damage. This collection of consensus protocols includes adaptations for a wide range of species and sample types, assay formats and detection of different types of DNA lesions.

International audience; BACKGROUND & AIMS: NADPH oxidase 1 (NOX1) has emerged as a prime regulator of intestinal mucosa immunity and homeostasis. Dysregulation of NOX1 may cause inflammatory bowel disease (IBD). It is not clear how NOX1 is regulated in vivo under inflammatory conditions. We studied the role of CK2 in this process.METHODS: The NOX1 organizer subunit, NADPH oxidase organizer 1 (NOXO1), was immunoprecipitated from cytokine-treated colon epithelial cells, and bound proteins were identified by mass spectrometry analysis. Sites on NOXO1 phosphorylated by CK2 were identified by nanoscale liquid chromatography coupled to tandem mass spectrometry. NOX1 activity was determined in colon epithelial cells and colonoids in the presence or absence of CX-4945, a CK2 specific inhibitor. Acute colitis was induced by administration of trinitrobenzenesulfonic acid in mice treated or not with CX-4945. Colon tissues were analyzed by histologic examination, quantitative polymerase chain reaction, and Western blots. CK2 activity, markers of inflammation, and oxidative stress were assessed.RESULTS: We identified CK2 as a major partner of NOXO1 in colon epithelial cells under inflammatory conditions. CK2 directly binds NOXO1 at the C-terminus containing the Phox homology domain and phosphorylates NOXO1 on several sites. CX-4945 increased ROS generation by NOX1 in human colon epithelial cells and organoids. Strikingly, CK2 activity was reduced in trinitrobenzenesulfonic acid-induced acute colitis, and CX-4945 exacerbated colitis inflammation as shown by increased levels of CXCL1, ROS generation, lipid peroxidation, and colon damage.CONCLUSIONS: The ubiquitous protein kinase CK2 limits NOX1 activity via NOXO1 binding and phosphorylation in colonic epithelial cells and lessens experimental colitis. Loss of CK2 activity during acute colitis results in excessive ROS production, contributing to the pathogenesis. Strategies to activate CK2 could be an effective novel therapeutic approach in IBD.

Complete proteomic datasets are available in the PRIDE partner repository (Perez-Riverol et al., 2019) under identification numbers: PXD030822 and 10.6019/PXD030822 for HepaRG cells, PXD031045 and 10.6019/PXD031045 for HepaRG culture media, PXD030887 and 10.6019/PXD030887 for PHHs, and PXD030892 and 10.6019/PXD030892 for PRHs. Metabolomic data are available in the MetaboLights repository (Haug et al., 2020) under the identification number: www.ebi.ac.uk/metabolights/MTBLS4063.; International audience; The biological effects of the pesticide and mitochondrial complex I inhibitor tebufenpyrad (TEBU) on liver cells were investigated by combining proteomics and metabolomics. Both cell culture media and cellular lysates were analyzed in dose-response and kinetic experiments on the HepaRG cell line. Responses were compared with those obtained on primary human and rat hepatocytes. A multitude of phase I and II metabolites (>80) mainly common to HepaRG cells and primary hepatocytes and an increase in metabolization enzymes were observed. Synthesis of mitochondrion and oxidative phosphorylation complex constituents, fatty acid oxidation, and cellular uptake of lipids were induced to compensate for complex I inhibition and the decrease in ATP intracellular contents caused by TEBU. Secretion of the 20 S circulating proteasome and overall inhibition of acute inflammation followed by IL-6 secretion in later stages were observed in HepaRG cells. These effects were associated with a decrease in STAT1 and STAT3 transcription factor abundances, but with different kinetics. Based on identified TEBU targets, docking experiments, and nuclear receptor reporter assays, we concluded that liver cell response to TEBU is mediated by its interaction with the PPARγ transcription factor.

Citation suggérée :Anses. (2022). Avis relatif à l’évaluation du risque de la fraction nanométrique de l’additif alimentaire E171(saisine 2016-SA-0226). Maisons-Alfort : Anses, 115 p.; Dans de nombreux domaines comme celui de l’agroalimentaire, les nanomatériaux manufacturés sont utilisés pour leurs propriétés propres à la nano-échelle (propriétés optiques, mécaniques, etc.) ainsi que pour leur importante surface spécifique. Les nanomatériaux manufacturés peuvent être ajoutés volontairement en tant qu’additifs alimentaires ou en tant qu’additifs technologiques dans la formulation des matériaux au contact des denrées alimentaires. Les nanomatériaux ne s’inscrivent pas dans une réglementation spécifique, mais sont régis par diverses réglementations sectorielles déjà existantes (CE n°258/971, UE n°1169/20112, UE n°10/20113 , etc.). La question de l’harmonisation sur le plan réglementaire fait partie des enjeux et préoccupations soulevés par des organisations de la société civile, principalement des organisations non gouvernementales (ONG), quant aux nanomatériaux en général et dans l’alimentation en particulier. La coexistence de définitions hétérogènes d’un nanomatériau au sein de ces réglementations sectorielles contribue à entretenir des confusions, notamment par l’interprétation des différents termes employés. Dans ce contexte, le groupe de travail (GT) de l’Anses « nano et alimentation » a établi, dans le cadre de son expertise, une qualification du terme « nanomatériau manufacturé » (Anses 2020) afin de préciser le champ de l’analyse. (extrait)

International audience; Cross-contamination of animal feed with antibiotics may occur during manufacturing in feed mills, because shared production lines can be used for medicated and non-medicated feed, but may also occur during transport, storage and at the farm level. This is a major issue in the current context where antimicrobial usage must be controlled in order to maintain their effectiveness. A LC-MS/MS method was developed for the determination of colistin, bacitracin A and virginiamycin M1 in feed for pigs, poultry and rabbits at concentrations similar to those encountered in cross-contamination. After investigating various issues related to colistin behaviour and matrix effects, we successfully validated this method according to the requirements of European regulations in terms of linearity, trueness, precision, limit of quantification and limit of decision. Trueness ranged 88.6–107.8% and precision ranged 12.6–21.2%. We then applied this method to the analysis of medicated pig feed to check the performance of the method on “real” samples of medicated feed. We subsequently analysed non-medicated pig, and rabbit feed samples, collected directly on farms, to check the rate of cross-contamination. No samples were contaminated by colistin, bacitracin, or virginiamycin.

The in vitro comet assay is a widely applied method for investigating genotoxicity of chemicals including engineered nanomaterials (NMs). A big challenge in hazard assessment of NMs is possible interference between the NMs and reagents or read-out of the test assay, leading to a risk of biased results. Here, we describe both the standard alkaline version of the in vitro comet assay with 12 mini-gels per slide for detection of DNA strand breaks and the enzyme-modified version that allows detection of oxidized DNA bases by applying lesion-specific endonucleases (e.g., formamidopyrimidine DNA glycosylase or endonuclease III). We highlight critical points that need to be taken into consideration when assessing the genotoxicity of NMs, as well as basic methodological considerations, such as the importance of carrying out physicochemical characterization of the NMs and investigating uptake and cytotoxicity. Also, experimental design-including treatment conditions, cell number, cell culture, format and volume of medium on the plate-is crucial and can have an impact on the results, especially when testing NMs. Toxicity of NMs depends upon physicochemical properties that change depending on the environment. To facilitate testing of numerous NMs with distinct modifications, the higher throughput miniaturized version of the comet assay is essential. ispartof: FRONTIERS IN TOXICOLOGY vol:4 ispartof: location:Switzerland status: published

The foodborne pathogen, Listeria monocytogenes, (Lm), frequently undergoes selection pressure associated with the extensive use of disinfectants, such as quaternary ammonium compounds, which are widely used in food processing plants. The repeated exposure to sub-inhibitory biocide concentrations can induce increased tolerance to these compounds, but can also trigger the development of antibiotic resistance, and both increase the risk of food contamination and persistence in food production environments. Although the acquisition of genes can explain biocide tolerance, the genetic mechanisms underlying the adaptive cross-resistance to antibiotics remain unclear. We previously showed that repeated exposure to benzalkonium chloride (BC) and didecyldimethyl ammonium chloride (DDAC) led to reduced susceptibility to ciprofloxacin in Lm strains from diverse sources. Here, we compared the genomes of 16 biocide-adapted and 10 parental strains to identify the molecular mechanisms of fluoroquinolone cross-resistance. A core genome SNP analysis identified various mutations in the transcriptional regulator fepR (lmo2088) for 94% of the adapted strains and mutations in other effectors at a lower frequency. FepR is a local repressor of the MATE fluoroquinolone efflux pump FepA. The impact of the mutations on the structure and function of the protein was assessed by performing in silico prediction and protein homology modeling. Our results show that 75% of the missense mutations observed in fepR are located in the HTH domain of the protein, within the DNA interaction site. These mutations are predicted to reduce the activity of the regulator, leading to the overexpression of the efflux pump responsible for the ciprofloxacin-enhanced resistance.

International audience; Mycotoxins and their metabolites are a family of compounds that contains a great diversity of both structure and biological properties. Information on their toxicity is spread within several databases and in scientific literature. Due to the number of molecules and their structure diversity, the cost and time required for hazard evaluation of each compound is unrealistic. In that purpose, new approach methodologies (NAMs) can be applied to evaluate such large set of molecules. Among them, quantitative structure-activity relationship (QSAR) in silico models could be useful to predict the mutagenic and carcinogenic properties of mycotoxins. First, a complete list of 904 mycotoxins and metabolites was built. Then, some known mycotoxins were used to determine the best QSAR tools for mutagenicity and carcinogenicity predictions. The best tool was further applied to the whole list of 904 mycotoxins. At the end, 95 mycotoxins were identified as both mutagen and carcinogen and should be prioritized for further evaluation.

Citation suggérée :Anses. (2022). Valeurs toxicologiques de référence (VTR). Elaboration de VTR par voie respiratoire pour l’acroléine (CAS n°107-02-8). (saisine 2021-MPEX-0149). Maisons-Alfort : Anses, 90 p.; Une valeur toxicologique de référence (VTR) est un indice toxicologique qui permet de qualifier ou de quantifier un risque pour la santé humaine. Elle établit le lien entre une exposition à une substance toxique et l’occurrence d’un effet sanitaire indésirable. Les VTR sont spécifiques d’une durée d’exposition (aiguë, subchronique ou chronique) et d’une voie d’exposition (orale, respiratoire, etc.). La construction des VTR diffère en fonction des connaissances ou des hypothèses formulées sur les mécanismes d’action des substances. Actuellement, l’hypothèse par défaut est de considérer une relation entre l’exposition, ou la dose, et l’effet, ou la réponse. En l’état actuel des connaissances et par défaut, on considère généralement que, pour les effets non cancérogènes, la toxicité ne s’exprime qu’au-delà d’un seuil de dose (Anses, 2017).En pratique, la construction de VTR comprend les quatre étapes suivantes :- recenser et analyser les données de toxicité disponibles, sur la base d‘études épidémiologiques et/ou expérimentales,- identifier le ou les organes cibles et l’effet critique ;- identifier l’hypothèse de construction, à seuil ou sans seuil de dose, en fonction du mode d’action de la substance,- choisir une étude clé de bonne qualité scientifique permettant généralement d’établir une relation dose – réponse ;- définir un point de départ (PoD) chez l’Homme ou l’animal à partir de cette étude, éventuellement dans le cas d’un PoD obtenu chez l’animal, ajuster ce PoD à l’Homme ;- pour une VTR à seuil, appliquer des facteurs d’incertitude à ce PoD de manière à dériver une VTR applicable à l’ensemble de la population ;- pour une VTR sans seuil, réaliser une extrapolation linéaire à l’origine afin de déterminer un excès de risque unitaire2.L’élaboration des VTR suit une approche très structurée et exigeante qui implique des évaluations collectives par des groupes de spécialistes.[Saisines liées n°2020-MPEX-0184, 2008-SA-0205, 2011-SA-0354]

International audience; Antibiotic excretion into milk depends on several factors such as the compound's physicochemical properties, the animal physiology, and the milk composition. The objective of this study was to develop a physiologically based pharmacokinetic (PBPK) model describing the passage of drugs into the milk of lactating species. The udder is described as a permeability limited compartment, divided into vascular, extracellular water (EW), intracellular water (IW) and milk, which was stored in alveolar and cistern compartments. The pH and ionization in each compartment and the binding to IW components and to milk fat, casein, whey protein, calcium, and magnesium were considered. Bidirectional passive diffusion across the blood-milk barrier was implemented, based on in vitro permeability studies.The model application used to predict the distribution of oxytetracycline in cow and goat milk, after different doses and routes of administration, was successful. By integrating inter-individual variability and uncertainty, the model also allowed a suitable estimation of the withdrawal periods.Further work is in progress to evaluate the predictive ability of the PBPK model for compounds with different physico-chemical properties that are potentially actively transported in order to extrapolate the excretion of xenobiotics in milk of various animal species including humans.

Since 2011, ANSES has been asked on several occasions to examine the health risks associated with perchlorate (ClO4-) in DW following the identification of situations in which resources used for DW production were contaminated. In 2011, the Agency had recommended a guideline value (GV) for perchlorate in DW of 15 µg.L-1 for adult consumers, derived from the TRV of 0.7 µg.kg bw-1.d-1(ANSES, 2011), based on the inhibition of iodine uptake by the thyroid gland. ANSES had also advised against using water contaminated by perchlorate when preparing feeding bottles for infants aged up to 6 months, pending a national survey on perchlorate contamination of food, in particular to clarify the concentrations found in the powdered infant formula used for bottle preparation.In 2012, in its opinion concerning epidemiological studies on associations between exposure to perchlorate in DW and thyroid function in specific populations, the Agency had concluded that: "the results from the evaluated epidemiological studies do not enable conclusions to be drawn concerning the possible association between thyroid-stimulating hormone (TSH) levels and perchlorate concentrations in drinking water in pregnant women and newborns [...]. The absence of information concerning the iodine status of the studied populations makes it difficult to interpret the published epidemiological data." (ANSES, 2012).In its opinion of 8 April 2014 on the presence of perchlorate in infant formula and in DW, the Agency had noted the same limitations relating to the available epidemiological studies and insisted on the need to take account of the iodine status of the study population for assessing the health impact of human exposure to perchlorate and for interpreting the published epidemiological data.In its opinion of 26 December 2018, the Agency had concluded that recent epidemiological studies, including the one by the French Institute for Public Health Surveillance1(InVS) published in 2016, did not provide any additional conclusive evidence on the biological or clinical effects of perchlorate versus those taken into account in the previous ANSES opinions (ANSES 2011, 2012, 2014). The data examined in this opinion did not call into question the conclusions of the previous ANSES opinions concerning the hazard characterisation and the RV proposed by the Agency in 2011.However, with regard to the assessment of exposure to perchlorate, new data made it possible to estimate the average oral exposure of the adult population to perchlorate. This estimate was based firstly on data on perchlorate contamination of food collected by the Directorate General for Competition Policy, Consumer Affairs and Fraud Control (DGCCRF) as part of its national surveys, and secondly on data on DW contamination for the period 2014-2017 produced by the Regional Health Agencies (ARSs) and available in the SISE-Eaux database. On this basis, ANSES estimated that exposure via DW consumption accounted for about 25% of ingestion exposure. As this estimate was in line with the data in the literature and was close to the 20% default percentage defined by the World Health Organization (WHO) in 2016, the Agency felt it necessary to lower to 20% the share of exposure via water (which had previously been set at 60%) used for calculating the GV of perchlorate in DW for adults. As a result, the proposed GV was lowered to 5 µg.L-1 for the adult population.ANSES also emphasised that the existing data on food contamination were too incomplete to characterise the distribution of the general population's exposure to perchlorate by the oral route and to assess the health risk. It therefore recommended that perchlorate be included in the third French Total Diet Study (TDS3).In the absence of new data on the contamination of infant formula with perchlorate since the 2014 expert appraisal, the Agency also reiterated the conclusions of this earlier expert appraisal: "daily intakes of perchlorate, calculated on the basis of perchlorate levels in infant formulas available on the French market, do not exceed the TRV of 0.7 µg.kg bw-1.d-1for 95% of the population of children aged under 6 months consuming infant formula based on an average concentration of perchlorate of 1 µg.L-1in DW for reconstituting infant bottles" (ANSES, 2018).Lastly, ANSES indicated in this same 2018 opinion, in Section 3.2.8 concerning the conclusions on the choice of the TRV, that the Working Group on "Assessment of the health risks associated with chemical parameters in drinking water" (ERS EDCH) and the Expert Committee (CES) on "Water" considered that in any future assessment of the health risks associated with the ingestion of perchlorate, following publication of the work under way by the US EPA, it would be necessary to re-examine the method for determining the critical dose and establishing the TRV for perchlorate."All the agencies establishing chronic oral TRVs for perchlorate have chosen inhibition of iodine uptake by the thyroid as the critical effect (Table 1 on page 8).In 2019, the US EPA adopted a different approach based on toxicokinetic-toxicodynamic modelling to assess the impact of perchlorate exposure on thyroid hormone (TH) production and the effect of a reduction in maternal plasma free thyroxine (fT4) concentrations during the first trimester of pregnancy on the child's neurodevelopment, as measured by a decrease in intelligence quotient. The US EPA suggested adopting a TRV of 2.2 µg.kg bw-1.d-1, resulting in a maximum contaminant level of 56 µg.L-1 perchlorate in DW.As mentioned previously, and in view of the management difficulties encountered, the DGS had formally asked ANSES to analyse the US EPA's work on assessing the health risks associated with the presence of perchlorate in DW, in order to provide the ARSs with appropriate and proportionate guidance on the health risk.In view of this, ANSES was asked to re-examine the assessment of the health risks associated with the ingestion of perchlorate, in light of the US EPA's work. The first deliverable of this formal request therefore had the ultimate objective of determining whether the ANSES TRV of 0.7 µg.kg bw1.d-1 should be maintained. This first deliverable concluded that this TRV should not be called into question in light of the US EPA's work, mainly because of major uncertainties about the predictive ability of the model used. The Agency therefore decided to retain its chronic oral TRV established in 2011, based on the no-effect level observed in the study by Greer et al. (2002). However, all the TRVs established since that date are based on a Benchmark Dose (BMD) approach, so the Agency therefore issued an internal request to assess the relevance of this approach, based in particular on recent publications (Weterings et al. 2016, Bruce et al. 2018, Haber et al. 2021).; Depuis 2011, l’Anses a été saisie à plusieurs reprises sur les risques sanitaires liés aux ions perchlorate (ClO4-) dans les eaux destinées à la consommation humaine (EDCH), suite à la mise en évidence de situations de contamination de ressources utilisées pour la production d’EDCH. En 2011, l’Agence avait préconisé une valeur guide (VG) pour les ions perchlorate dans les EDCH de 15 µg.L-1 pour le consommateur adulte, définie à partir de la VTR de 0,7 µg.kg p.c.-1.j-1(Anses, 2011), fondée sur l’inhibition du captage de l’iode par la thyroïde. L’Anses avait également conseillé de ne pas utiliser une eau contaminée par les ions perchlorate pour la préparation des biberons des nourrissons jusqu’à 6 mois, dans l'attente de la réalisation d’une enquête nationale sur la contamination des aliments en perchlorates, en particulier pour préciser les concentrations retrouvées dans les formulations de lait maternisé en poudre utilisées pour la préparation des biberons.En 2012, dans son avis relatif aux études épidémiologiques portant sur les associations entre une exposition aux ions perchlorate dans les EDCH et la fonction thyroïdienne dans des populations spécifiques, l’Agence concluait : « les résultats des études épidémiologiques examinées par les experts ne permettent pas de conclure quant à l’existence ou à l’absence d’une association chez les femmes enceintes ou les nouveau-nés entre les niveaux de thyréostimuline (TSH, thyroid stimulating hormone) et des concentrations en ions perchlorate dans les eaux de boisson […]. L’absence d’information concernant le statut en iode des populations étudiées rend difficile l’interprétation des données épidémiologiques publiées. »(Anses, 2012).Dans son avis du 8 avril 2014 relatif à la présence d’ions perchlorate dans le lait infantile et dans les EDCH, l’Agence relevait les mêmes limites relatives aux études épidémiologiques disponibles et insistait sur la nécessité de prendre en compte le statut en iode de la population étudiée pour l’évaluation de l’impact sanitaire de l’exposition aux ions perchlorate chez l’Homme et pour l’interprétation des données épidémiologiques publiées.Dans son avis du 26 décembre 2018, l’Agence concluait que les études épidémiologiques récentes, y compris celle de de l’Institut de veille sanitaire1(InVS) publiée en 2016, n’apportaient pas d’éléments conclusifs supplémentaires sur les effets biologiques ou cliniques des ions perchlorate par rapport à celles prises en compte dans les précédents avis de l’Anses (Anses 2011, 2012, 2014). Les données examinées dans cet avis n’étaient pas de nature à remettre en cause les conclusions des avis précédents de l’Anses, concernant la caractérisation des dangers et la VTR proposée en 2011 par l’Agence.Cependant, s’agissant de l’évaluation de l’exposition aux ions perchlorate, de nouvelles données ont permis d’estimer l’exposition moyenne de la population adulte aux ions perchlorate par voie orale. Cette estimation se fondait d’une part sur les données de contamination des aliments par les ions perchlorate, recueillies par la Direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF) dans le cadre de ses enquêtes nationales et d’autre part sur les données de contamination des EDCH pour la période 2014-2017, produites par les Agences régionales de santé (ARS) et disponibles dans la base de données SISE-Eaux. Sur cette base, l’Anses estimait que la contribution de ’exposition liée à la consommation d’EDCH représente environ 25% de l’exposition par ingestion. Cette estimation concordant avec les données de la littérature et se rapprochant du pourcentage de 20% défini par défaut par l’Organisation Mondiale de la Santé (OMS) en 2016, l’Agence considérait nécessaire d’abaisser à 20% la part de l’exposition hydrique pour le calcul de la VG des ions perchlorate dans les EDCH pour les adultes, antérieurement fixée à 60%. En conséquence, la VG proposée avait été abaissée à 5 µg.L-1 pour la population adulte. L’Anses soulignait, par ailleurs, que les données existantes de contamination des aliments étaient trop parcellaires pour caractériser la distribution de l’exposition de la population générale aux ions perchlorate par voie orale et évaluer le risque sanitaire. En conséquence, elle recommandait de prendre en compte les ions perchlorate lors de l’étude de l’alimentation totale (EAT) 3.En l’absence de nouvelles données de contamination des laits infantiles par les ions perchlorate depuis l’expertise de 2014, l’Agence rappelait également les conclusions de ce précédent avis : « les apports journaliers en ions perchlorate, calculés sur la base des teneurs en ions perchlorate des laits infantiles disponibles sur le marché français, ne dépassent pas la VTR de 0,7 µg.kg p.c.-1.j-1 pour 95% de la population des enfants âgés de moins de 6 mois consommateurs de laits infantiles sur la base d’une concentration moyenne en ions perchlorate dans l’EDCH de 1 µg.L-1 pour la reconstitution des biberons » (Anses, 2018).Enfin, l’Anses indiquait dans ce même avis publié en 2018, au paragraphe 3.2.8 relatif aux conclusions sur le choix de la VTR : « le groupe de travail « Évaluation des risques sanitaires associés aux paramètres chimiques des eaux destinées à la consommation humaine) » (ERS EDCH) et le comité d’experts spécialisés (CES) « Eaux » estiment qu’en cas de future évaluation des risques sanitaires liés à l’ingestion d’ions perchlorate postérieure à la publication des travaux en cours de l’US EPA, il sera nécessaire de réexaminer le mode de détermination de la dose critique et de construction de la VTR des ions perchlorate. »L’ensemble des organismes établissant une VTR chronique par voie orale pour les ions perchlorate ont retenu comme effet critique l'inhibition du captage de l'iode au niveau thyroïdien (Tableau 1 en page 8). En 2019, l'US EPA a adopté une approche différente reposant d'une part sur une modélisation toxicocinétique-toxicodynamique permettant d'évaluer l'impact d'une exposition aux ions perchlorate sur la production d'hormones thyroïdiennes (HT) et d'autre part d'évaluer l'effet d’une diminution des concentrations plasmatiques de thyroxine libre (fT4) maternelles lors du premier trimestre de grossesse sur le neurodéveloppement de l’enfant, objectivé par une baisse du quotient intellectuel. L’US EPA suggérait de retenir une VTR de 2,2 µg.kg p.c.-1.j-1, aboutissant à une valeur de gestion de 56 µg.L-1 en ions perchlorate dans les EDCH.Comme mentionné précédemment et au regard des difficultés de gestion rencontrées, la DGS avait saisi l’Anses pour analyser les travaux de l’US EPA relatifs à l’évaluation des risques sanitaires liés à la présence d’ions perchlorate dans l’EDCH, afin de donner aux ARS des orientations adaptées et proportionnées au risque sanitaire.Compte tenu de ces éléments, l’Anses avait donc été sollicitée pour examiner à nouveau l’évaluation des risques sanitaires liés à l’ingestion d’ions perchlorate, à la lumière des travaux de l’US EPA. Le premier livrable de cette saisine a eu, par conséquent, pour objectif final de déterminer si la VTR de l’Anses à 0,7 µg.kg p.c.-1.j-1 devait être maintenue. La conclusion de ce premier livrable fut de ne pas remettre en cause cette VTR à la lumière des travaux de l’US EPA, du fait notamment d’incertitudes majeures sur la capacité prédictive du modèle utilisé.L’Agence a donc décidé de conserver sa VTR chronique par voie orale établie en 2011, fondée sur la dose sans effet observée dans l’étude de Greer et al. (2002). Cependant, toutes les VTR établies depuis cette date s’appuient sur une approche Benchmark Dose (BMD), de sorte que l’Agence s’est auto-saisie pour évaluer la pertinence de cette approche, en s’appuyant notamment sur les publications récentes (Weterings et al. 2016, Bruce et al. 2018, Haber et al. 2021).[Saisines liées : 1-SA-0336 ; 2012-SA-0119 ; 2016-SA-0155 et 2017-SA-0170]

International audience; Pesticides are now recognised to interact with drug transporters, but only few data are available on this issue for carbamate pesticides, a widely-used class of agrochemicals, to which humans are highly exposed. The present study was therefore designed to determine whether four representative carbamate pesticides, i.e., the insecticides aminocarb and carbofuran, the herbicide chlorpropham and the fungicide propamocarb, may impair activities of main drug transporters implicated in pharmacokinetics.The interactions of carbamates with solute carrier and ATP-binding cassette transporters were investigated using cultured transporter-overexpressing cells, reference substrates and spectrofluorimetry-, liquid chomatography/tandem mass spectrometry- or radioactivity-based methods.Aminocarb and carbofuran exerted no or minimal effects on transporter activities, whereas chlorpropham inhibited BCRP and OAT3 activities and propamocarb decreased those of OCT1 and OCT2, but cis-stimulated that of MATE2-K. Such alterations of transporters however required chlorpropham/propamocarb concentrations in the 5-50 µM range, likely not relevant to environmental exposure. Trans-stimulation assays and propamocarb accumulation experiments additionally suggested that propamocarb is not a substrate for OCT1, OCT2 and MATE2-K.These data indicate that some carbamate pesticides can interact in vitro with some drug transporters, but only when used at concentrations higher than those expected to occur in environmentally-exposed humans.

International audience; This study aimed to characterize third-generation cephalosporin (3GC)-resistant Klebsiella pneumoniae isolated from fresh fruits and vegetables purchased at Bejaia city, Algeria. K. pneumoniae isolates were identified by MALDI-TOF. Susceptibility to antibiotics was tested by the disk diffusion method. Whole genome sequencing (WGS) was carried out to determine sequence type (ST), plasmid incompatibility group (Inc.), and acquired antimicrobial resistance gene presence. A total of 13 3GC-resistant K. pneumoniae strains were isolated. WGS identified blaCTX-M-15 in 11 extended-spectrum-beta-lactamases (ESBL)-K. pneumoniae and blaDHA-1 in 2 AmpC-K. pneumoniae. The aac(6')lb-cr gene was identified in 8 out of 13 isolates. Multilocus sequence typing (MLST) evidenced five different STs, namely ST14, ST45, ST219, ST236, and ST882. MDR K. pneumoniae contaminated fresh fruits and vegetables, often eaten raw and inappropriately washed, may represent an underestimated public health threat. This study highlights that hygiene measures during harvesting and retail process are of utmost importance to limit further ESBL/AmpC spread to the consumer households.

Listeria monocytogenes (Lm) is a ubiquitous bacterium that causes listeriosis, a serious foodborne illness. In the nature-to-human transmission route, Lm can prosper in various ecological niches. Soil and decaying organic matter are its primary reservoirs. Certain clonal complexes (CCs) are over-represented in food production and represent a challenge to food safety. To gain new understanding of Lm adaptation mechanisms in food, the genetic background of strains found in animals and environment should be investigated in comparison to that of food strains. Twenty-one partners, including food, environment, veterinary and public health laboratories, constructed a dataset of 1484 genomes originating from Lm strains collected in 19 European countries. This dataset encompasses a large number of CCs occurring worldwide, covers many diverse habitats and is balanced between ecological compartments and geographic regions. The dataset presented here will contribute to improve our understanding of Lm ecology and should aid in the surveillance of Lm. This dataset provides a basis for the discovery of the genetic traits underlying Lm adaptation to different ecological niches.

This study was conducted to evaluate the performance of a screening protocol to detect and isolate mcr-positive Escherichia coli and Salmonella spp. from animal caecal content and meat samples. We used a multicentre approach involving 12 laboratories from nine European countries. All participants applied the same methodology combining a multiplex PCR performed on DNA extracted from a pre-enrichment step, followed by a selective culture step on three commercially available chromogenic agar plates. The test panel was composed of two negative samples and four samples artificially contaminated with E. coli and Salmonella spp. respectively harbouring mcr-1 or mcr-3 and mcr-4 or mcr-5 genes. PCR screening resulted in a specificity of 100% and a sensitivity of 83%. Sensitivity of each agar medium to detect mcr-positive colistin-resistant E. coli or Salmonella spp. strains was 86% for CHROMID(R)Colistin R, 75% for CHROMagarTM COL-APSE and 70% for COLISTIGRAM. This combined method was effective to detect and isolate most of the E. coli or Salmonella spp. strains harbouring different mcr genes from food-producing animals and food products and might thus be used as a harmonized protocol for the screening of mcr genes in food-producing animals and food products in Europe.

Background TiO2 nanomaterials (NMs) are present in a variety of food and personal hygiene products, and consumers are exposed daily to these NMs through oral exposition. While the bulk of ingested TiO2 NMs are eliminated rapidly in stool, a fraction is able to cross the intestinal epithelial barrier and enter systemic circulation from where NMs can be distributed to tissues, primarily liver and spleen. Daily exposure to TiO2 NMs, in combination with a slow rate of elimination from tissues, results in their accumulation within different tissues. Considerable evidence suggests that following oral exposure to TiO2 NMs, the presence of NMs in tissues is associated with a number of adverse effects, both in intestine and liver. Although numerous studies have been performed in vitro investigating the acute effects of TiO2 NMs in intestinal and hepatic cell models, considerably less is known about the effect of repeated exposure on these models. In this study, we investigated the cytotoxic effects of repeated exposure of relevant models of intestine and liver to two TiO2 NMs differing in hydrophobicity for 24 h, 1 week and 2 weeks at concentrations ranging from 0.3 to 80 µg/cm2. To study the persistence of these two NMs in cells, we included a 1-week recovery period following 24 h and 1-week treatments. Cellular uptake by TEM and ToF–SIMS analyses, as well as the viability and pro-inflammatory response were evaluated. Changes in the membrane composition in Caco-2 and HepaRG cells treated with TiO2 NMs for up to 2 weeks were also studied. Results Despite the uptake of NM-103 and NM-104 in cells, no significant cytotoxic effects were observed in either Caco-2 or HepaRG cells treated for up to 2 weeks at NM concentrations up to 80 µg/cm2. In addition, no significant effects on IL-8 secretion were observed. However, significant changes in membrane composition were observed in both cell lines. Interestingly, while most of these phospholipid modifications were reversed following a 1-week recovery, others were not affected by the recovery period. Conclusion These findings indicate that although no clear effects on cytotoxicity were observed following repeated exposure of differentiated Caco-2 and HepaRG cells to TiO2 NMs, subtle effects on membrane composition could induce potential adverse effects in the long-term.

International audience; Although antimicrobials are generally found in trace amounts in meat, the human health risk they bear cannot be ignored. With the ultimate aim of making a better assessment of consumer exposure, this study explored the effects of pan cooking on sulfonamides and tetracyclines in meat. Screening of these antimicrobials in cooked meat was first performed by the European Union Reference Laboratory on the basis of HPLC-MS/MS analyses. A proof of concept approach using radiolabeling was then carried out on the most cooking-sensitive antimicrobial—sulfamethoxazole—to assess if a thermal degradation could explain the observed cooking losses. Degradation products were detected thanks to separation by HPLC and monitoring by online radioactivity detection. HPLC-Orbitrap HRMS analyses completed by 1D and 2D NMR experiments allowed the structural characterization of these degradation compounds. This study revealed that cooking could induce significant antimicrobial losses of up to 45% for sulfamethoxazole. Six potential degradation products of 14C-sulfamethoxazole were detected in cooked meat, and a thermal degradation pattern was proposed. This study highlights the importance of considering the cooking step in chemical risk assessment procedures and its impact on the level of chemical contaminants in meat and on the formation of potentially toxic breakdown compounds.

The European Food Safety Authority (EFSA) advised to prioritize monitoring carbapenemase producing Enterobacteriaceae (CPE) in food producing animals. Therefore, this study evaluated the performance of different commercially available selective agars for the detection of CPE using spiked pig caecal and turkey meat samples and the proposed EFSA cultivation protocol. Eleven laboratories from nine countries received eight samples (four caecal and four meat samples). For each matrix, three samples contained approximately 100 CFU/g CPE, and one sample lacked CPE. After overnight enrichment in buffered peptone water, broths were spread upon Brilliance™ CRE Agar (1), CHROMID® CARBA (2), CHROMagar™ mSuperCARBA™ (3), Chromatic™ CRE (4), CHROMID® OXA-48 (5) and Chromatic™ OXA-48 (6). From plates with suspected growth, one to three colonies were selected for species identification, confirmation of carbapenem resistance and detection of carbapenemase encoding genes, by methods available at participating laboratories. Of the eleven participating laboratories, seven reported species identification, susceptibility tests and genotyping on isolates from all selective agar plates. Agars 2, 4 and 5 performed best, with 100% sensitivity. For agar 3, a sensitivity of 96% was recorded, while agar 1 and 6 performed with 75% and 43% sensitivity, respectively. More background flora was noticed for turkey meat samples than pig caecal samples. Based on this limited set of samples, most commercially available agars performed adequately. The results indicate, however, that OXA-48-like and non-OXA-48-like producers perform very differently, and one should consider which CPE strains are of interest to culture when choosing agar type.

Citation suggérée :Anses. (2022). Avis de l’Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail relatif à l’évaluation du 3a,4,7,7a-tetrahydro-1H-4,7-methanoindene (n° CAS 77-73-6) dans le cadre de l’évaluation des substances sous REACH. (saisine 2016-REACH-0302). Maisons-Alfort : Anses, 13 p.; Dans le cadre de la procédure d’évaluation des substances prévue par le Règlement REACH n°1907/2006 (articles 44 à 48), les Etats Membres de l’Union européenne et des pays de l’Espace économique européen (à savoir la Norvège, l’Islande et le Liechtenstein) évaluent chaque année des substances jugées prioritaires, dans le but de clarifier une ou des préoccupation(s) émanant de la fabrication et/ou de l’utilisation de ces substances et qui pourrai(en)t entrainer un risque pour la santé humaine et/ou pour l’environnement.Ces substances sont inscrites sur le plan d’action continu communautaire (CoRAP), publié sur le site internet de l’Agence européenne des produits chimiques (ECHA) avec une courte description des préoccupations initialement identifiées pour chacune des substances (https://echa.europa.eu/information-on-chemicals/evaluation/community-rolling-action-plan/corap-table). Dans la majorité des cas, ces préoccupations initiales sont liées aux propriétés de danger, en combinaison avec une utilisation susceptible de conduire à une dispersion environnementale ou avec des usages générant une exposition pour les consommateurs.Les Etats membres peuvent cibler leur évaluation sur la préoccupation initiale, mais peuvent aussi l’élargir à tout ou partie des autres propriétés de la substance. A l’issue des 12 mois d'évaluation par l’Etat membre évaluateur deux situations peuvent se présenter : a) des informations supplémentaires peuvent être demandées aux déclarants des substances, si ces données additionnelles sont jugées nécessaires pour lever un doute sur un danger suspecté. Dans ce cas, un projet de décision est discuté au sein du Comité des Etats-membres (CEM) de l’Agence européenne des produits chimiques (ECHA) ; b) il peut être conclu qu'aucune donnée supplémentaire n'est nécessaire et justifiée selon l’article 46 de REACH. Dans ce cas, un document de conclusion est rédigé. Il peut alors être accompagné ou suivi d’une analyse des options de gestion réglementaires à mettre en œuvre si des dangers ou des risques nécessitant une action réglementaire ont été identifiés lors de l’évaluation. En 2016, l’ANSES a pris en charge l’évaluation de quatre substances dont le 3a,4,7,7atetrahydro-1H-4,7-methanoindene ou dicyclopentadiène (DCPD) (n° EC 201-052-9, n° CAS 77-73-6). Le DCPD a été initialement inscrit au CoRAP en vue de son évaluation par la France sur la base d’une préoccupation pour ses possibles propriétés reprotoxiques. De plus, la substance est mise sur le marché à un tonnage agrégé élevé et les ratios de risques présents dans le dossier sont élevés. Enfin, les travailleurs pourraient être fortement exposés.L’évaluation de l’ANSES a couvert l’ensemble des données relatives à la physico-chimie, la santé humaine et l’environnement.

The emergence of antimicrobial resistance (AMR) is one of the biggest health threats globally. In addition, the use of antimicrobial drugs in humans and livestock is considered an important driver of antimicrobial resistance. The commensal microbiota, and especially the intestinal microbiota, has been shown to have an important role in the emergence of AMR. Mobile genetic elements (MGEs) also play a central role in facilitating the acquisition and spread of AMR genes. We isolated Escherichia coli (n = 627) from fecal samples in respectively 25 poultry, 28 swine, and 15 veal calf herds from 6 European countries to investigate the phylogeny of E. coli at country, animal host and farm levels. Furthermore, we examine the evolution of AMR in E. coli genomes including an association with virulence genes, plasmids and MGEs. We compared the abundance metrics retrieved from metagenomic sequencing and whole genome sequenced of E. coli isolates from the same fecal samples and farms. The E. coli isolates in this study indicated no clonality or clustering based on country of origin and genetic markers; AMR, and MGEs. Nonetheless, mobile genetic elements play a role in the acquisition of AMR and virulence genes. Additionally, an abundance of AMR was agreeable between metagenomic and whole genome sequencing analysis for several AMR classes in poultry fecal samples suggesting that metagenomics could be used as an indicator for surveillance of AMR in E. coli isolates and vice versa.

International audience; A liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous quantification of residues of spiramycin, a macrolide antibiotic, and its active metabolite neospiramycin in cow's milk as well as in minor species milk, goat and ewe. Spiramycin-d3 was used as internal standard for quantification of both analytes. This analytical method was validated using a global accuracy profile as a graphical decision tool built according to the trueness and the precision of the method. A unique and optimal linear model with logarithm transformation (with a determination coefficient of 0.9991) allowed the measurement of both analytes in the milks of the three animal species, in a wide range from 0.2 to 10 times the Maximal Residue Limit (MRL) (40-2000 µg.kg(-1)). The limits of detection and quantification were 13 µg.kg(-1) and 40 µg.kg(-1), respectively. The accuracy profile was established to get 80% of future measurements in routine assays that will fall within the acceptance limits. Trueness of the method, expressed as relative bias, was comprised between -1.6% and 5.7% over the whole range of concentrations. The mean relative standard deviation for repeatability and intermediate precision were comprised between 1.1% and 2.7%; 2.5 and 4.2%, respectively, in all levels of concentration for the three milks. Moreover, a two-order polynomial function was used to model the relative expanded uncertainty with a determination coefficient of 0.834. This function aimed to determine the uncertainty of the future quantifications within the validated dosing range. Overall, the global accuracy profile highlighted the reliability of the method for the routine assays of spiramycin and neospiramycin even in milk from minor species (goat, ewe) by using the most accessible milk (often from cow), while guaranteeing a very high proportion of samples within the fixed acceptance limits. The applicability of this method was tested during a depletion study of spiramycin and neospiramycin in the milk of cow, goat and ewe. The developed analytical method will be useful to assess the distribution profile of the antibiotic and its metabolite in milk of minor species where few studies are available.

Bacillus subtilis is a widely used bacterial model to decipher biofilm formation, genetic determinants and their regulation. For several years, studies were conducted on colonies or pellicles formed at the interface with air, but more recent works showed that non-domesticated strains were able to form thick and structured biofilms on submerged surfaces. Taking advantage of time-lapse confocal laser scanning microscopy, we monitored bacterial colonization on the surface and observed an unexpected biphasic submerged biofilm development. Cells adhering to the surface firstly form elongated chains before being suddenly fragmented and released as free motile cells in the medium. This switching coincided with an oxygen depletion in the well which preceded the formation of the pellicle at the liquid-air interface. Residual bacteria still associated with the solid surface at the bottom of the well started to express matrix genes under anaerobic metabolism to build the typical biofilm protruding structures.

Background: Exposure of consumers to aluminum-containing nanomaterials (Al NMs) through numerous products is an area of concern for public health agencies since human health risks are not completely elucidated. In addition, the available data on the genotoxicity of Al2O3 and Al0 NMs are inconclusive or rare. In order to provide further information, the present study investigated the in vitro genotoxic potential of Al0 and Al2O3 NMs in intestinal and liver cell models since these tissues represent organs which would be in direct contact or could experience potential accumulation following oral exposure. Methods: Differentiated human intestinal Caco-2 and hepatic HepaRG cells were exposed to Al0 and Al2O3 NMs (0.03 to 80 µg/cm2) and the results were compared with those obtained with the ionic form AlCl3. Several methods, including H2AX labelling, the alkaline comet assay and micronucleus (MN) assays were used. Oxidative stress and oxidative DNA damage were assessed using High Content Analysis (HCA) and the formamidopyrimidine DNA-glycosylase -modified comet assay respectively. Moreover, carcinogenic properties of Al NMs were investigated through the cell transforming assay (CTA) in Bhas 42 cells.Results: The three forms of Al did not induce chromosomal damage when tested in the MN assay. Furthermore, no cell transformation was observed in Bhas 42 cells. However, although no production of oxidative stress was detected in HCA assays, Al2O3 NMs induced oxidative DNA damage in Caco-2 cells in the comet assay following a 24 h treatment. Considerable DNA damage was observed with Al0 NMs in both cell lines in the comet assay, although this was likely due to interference with these NMs. Finally, no genotoxic effects were observed with AlCl3. Conclusion: The slight effects observed with Al NMs are therefore not likely to be related to ion release in the cell media.

International audience; Lipophilic phycotoxins are secondary metabolites produced by phytoplankton. They can accumulate in edible filtering-shellfish and cause human intoxications, particularly gastrointestinal symptoms. Up to now, the in vitro intestinal effects of these toxins have been mainly investigated on simple monolayers of intestinal cells such as the enterocyte-like Caco-2 cell line. Recently, the combination of Caco-2 cells with mucus secreting HT29-MTX cell line has been also used to mimic the complexity of the human intestinal epithelium. Besides, enteric glial cells (EGC) from the enteric nervous system identified in the gut mucosa have been largely shown to be involved in gut functions. Therefore, using a novel model integrating Caco-2 and HT29-MTX cells co-cultured on inserts with EGC seeded in the basolateral compartment, we examined the toxicological effects of two phycotoxins, pectenotoxin-2 (PTX2) and okadaic acid (OA). Cell viability, morphology, barrier integrity, inflammation, barrier crossing, and the response of some specific glial markers were evaluated using a broad set of methodologies. The toxicity of PTX2 was depicted by a slight decrease of viability and integrity as well as a slight increase of inflammation of the Caco-2/HT29-MTX co-cultures. PTX2 induced some modifications of EGC morphology. OA induced IL-8 release and decreased viability and integrity of Caco-2/HT29-MTX cell monolayers. EGC viability was slightly affected by OA. The presence of EGC reinforced barrier integrity and reduced the inflammatory response of the epithelial barrier following OA exposure. The release of GDNF and BDNF gliomediators by EGC could be implicated in the protection observed.

Citation suggérée : ANSES. (2021). Opinion of the French Agency for Food, Environmental and Occupational Health & Safety on a specific health risk assessment guide for nanomaterials in food products (Request 2016-SA-0226). Maisons-Alfort: ANSES, 86 p.

International audience; Avec pour thématique "Ma mère, mon Placenta et Moi", ce colloque a pour objectif d’encourager la recherche sur le placenta et les pathologies obstétricales associées, de faciliter les collaborations internationales francophones, et les échanges scientifiques et méthodologique dans notre domaine.

Dans le cadre de la procédure d’évaluation des substances prévue par le Règlement REACH n°1907/2006 (articles 44 à 48), les Etats Membres de l’Union européenne et des pays de l’Espace économique européen (à savoir la Norvège, l’Islande et le Liechtenstein ) évaluent chaque année des substances jugées prioritaires, dans le but de clarifier une ou des préoccupation(s) émanant de la fabrication et/ou de l’utilisation de ces substances et qui pourrai(en)t entrainer un risque pour la santé humaine et/ou pour l’environnement. Ces substances sont inscrites sur le plan d’action continu communautaire (CoRAP1), publié2 sur le site internet de l’Agence européenne des produits chimiques (ECHA) avec une courte description des préoccupations initialement identifiées pour chacune des substances. Dans la majorité des cas, ces préoccupations initiales sont liées aux propriétés de danger, en combinaison avec une utilisation susceptible de conduire à une dispersion environnementale ou des usages générant une exposition pour les consommateurs.Le CoRAP en 2013 incluait six substances dont l’évaluation a été confiée à l’Anses. La liste de ces substances figure sur le site internet de l’Agence européenne des produits chimiques (ECHA) avec une courte description des réoccupations initiales pour chacune des substances. Les Etats membres peuvent cibler leur évaluation sur la préoccupation initiale, mais peuvent aussi l’élargir à tout ou partie des autres propriétés de la substance. A l’issue des 12 mois d'évaluation par l’Etat membre évaluateur deux situations peuvent se présenter : a) des informations supplémentaires peuvent être demandées aux déclarants des substances, si ces données additionnelles sont jugées nécessaires pour lever un doute sur un danger suspecté. Dans ce cas, un projet de décision est discuté au sein du Comité des Etats-membres (CEM) de l’Agence européenne des produits chimiques (ECHA) ; b) il peut être conclu qu'aucune donnée supplémentaire n'est nécessaire. Dans ce cas, un document de conclusion est rédigé. Il peut alors être accompagné ou suivi d’une analyse des options de gestion réglementaires à mettre en œuvre si des dangers ou des risques ont été identifiés lors de l’évaluation ou si une préoccupation particulière est confirmée. Le disulfure de carbone (n° EC 200-843-6, n° CAS 75-15-0) a été initialement inscrit au CoRAP en vue de son évaluation par la France sur la base d’une préoccupation pour ses possibles propriétés reprotoxiques et de perturbation endocrinienne. Enfin, la substance est mise sur le marché à un tonnage agrégé élevé. Le disulfure de carbone pourrait être une source d’émission dans l’environnement importante. De plus, les travailleurs pourraient être fortement exposés

International audience; Estrogen receptor-alpha (ER alpha) is the driving transcription factor in 70% of breast cancers and its activity is associated with hormone dependent tumor cell proliferation and survival. Given the recurrence of hormone resistant relapses, understanding the etiological factors fueling resistance is of major clinical interest. Hypoxia, a frequent feature of the solid tumor microenvironment, has been described to promote endocrine resistance by triggering ER alpha down-regulation in both in vitro and in vivo models. Yet, the consequences of hypoxia on ER alpha genomic activity remain largely elusive. In the present study, transcriptomic analysis shows that hypoxia regulates a fraction of ER alpha target genes, underlying an important regulatory overlap between hypoxic and estrogenic signaling. This gene expression reprogramming is associated with a massive reorganization of ER alpha cistrome, highlighted by a massive loss of ER alpha binding sites. Profiling of enhancer acetylation revealed a hormone independent enhancer activation at the vicinity of genes harboring hypoxia inducible factor (HIF alpha) binding sites, the major transcription factors governing hypoxic adaptation. This activation counterbalances the loss of ER alpha and sustains hormone-independent gene expression. We describe hypoxia in luminal ER alpha (+) breast cancer as a key factor interfering with endocrine therapies, associated with poor clinical prognosis in breast cancer patients.

International audience; Poultry feathers are nowadays partially re-introduced into the animal food chain and the environment. They are valorised by their transformation into feather meal in order to be used as fertilisers in agriculture but also in animal feed (in particular, pet food and fish feed). However, unlike food producing animals for humans, feathers from poultry animals are not subject to a ban or regulatory limits on the presence of antibiotic residue after veterinary treatment. Feathers could therefore be a potential reservoir of antibiotic residues, unintentionally exposing the environment and animals through food, which might contribute to the emergence of antibiotic resistance. To this end, a multi-class liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the detection and determination of residues of 30 antibiotics from eight groups of antibacterial (quinolones, lincosamides, macrolides, penicillins, phenicols, tetracyclines, sulphonamides and diaminopyrimidines) in feathers. The extraction of the analytes from the feathers was carried out by the salting out technique. The separation of the analytes employed a Kinetex C18 column. Quantification was made using internal standards. All analytes have been validated according to the performance criteria of Decision 2002/657/EC. Trueness of the method ranged from to 93% to 111% for all analytes and intermediate precision were to 1.2-18.8%. The limits of quantification (LOQ) were from 13 to 150 µg kg(-1) depending on the analytes. The method is suitable for the monitoring and quantification of antibiotic residues in feathers over the range 13-600 µg kg(-1) depending on the compound.

International audience; Human fetal gonads acquire endocrine steroidogenic capabilities early during their differentiation. Genetic studies show that this endocrine function plays a central role in the sexually dimorphic development of the external genitalia during fetal development. When this endocrine function is dysregulated, congenital malformations and pathologies are the result. In this review, we explain how the current knowledge of steroidogenesis in human fetal gonads has benefited from both the technological advances in steroid measurements and the assembly of detailed knowledge of steroidogenesis machinery and its expression in human fetal gonads. We summarise how the conversion of radiolabelled steroid precursors, antibody-based assays, mass spectrometry, ultrastructural studies, and the in situ labelling of proteins and mRNA have all provided complementary information. In this review, our discussion goes beyond the debate on recommendations concerning the best choice between the different available technologies, and their degrees of reproducibility and sensitivity. The available technologies and techniques can be used for different purposes and, as long as all quality controls are rigorously employed, the question is how to maximise the generation of robust, reproducible data on steroid hormones and their crucial roles in human fetal development and subsequent functions.

International audience; Portimine, a recently identified cyclic imine produced by the dinoflagellate Vulcanodinium rugosum, has been described as a potent apoptotic agent in contrast to most of the cyclic imines that are well-known to be neurological toxins. As apoptosis can be a consequence of a high level of DNA lesions, we investigated the responses of portimine on several endpoints aimed at detecting DNA damage in the hepatic cell line HepaRG. Portimine induced phosphorylation of H2AX, which could possibly be consistent with the previously published induction of apoptosis with this toxin. In addition, detection of apoptosis through the activation of caspase-3, the induction of strand breaks detected by the comet assay as well as chromosome and genome mutations using the micronucleus assay were addressed. Surprisingly, portimine treatment resulted in increases in only γH2AX in differentiated HepaRG cells whereas no effects on the other endpoints were detected. These increases in γH2AX in the absence of genotoxic effects in the other tests could indicate that portimine could possibly induce a DNA replication stress and/or that the compound can be detoxified by the HepaRG cells.

International audience; A qualitative and quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the sensitive and exhaustive analysis of residues from triarylmethane dyes, triarylmethane-derivative dyes, phenothiazines, phenoxazines and xanthenes in aquaculture samples. For a wider and more robust detection of dye misuse on farms, other residue markers were also included the leuco forms of brilliant green, crystal violet and malachite green; one direct metabolite of Victoria pure blue BO and methylene blue and three bile acids, which are endogenous markers of the effects of dye contamination in fish. We optimised the extraction method by comparing several extraction solvents and sample solvents reported in the literature to have the best extraction efficiency. The residues were determined using a positive electrospray ionisation source. We assessed the parameters of this LC-MS/MS method by evaluating the matrix effects, identification and quantitative parameters according to the criteria stipulated in the European Commission Decision No. 2002/657/EC. A study on the applicability of the method was conducted on various aquaculture species and on a positive catfish.

International audience; In February–March, 2021, a Working Group of 11 scientists from eight countries met remotely at the invitation of the International Agency for Research on Cancer (IARC) to finalise their evaluation of the carcinogenicity of five agents used as dyes and reagents, and for their antibacterial and antifungal properties.

Antibiotic resistance is one of the most important issues facing modern medicine. Some biocides have demonstrated the potential of selecting resistance to antibiotics in bacteria, but data are still very scarce and it is important to better identify the molecules concerned and the underlying mechanisms. This study aimed to assess the potential of polyhexamethylene biguanide (PHMB), a widely used biocide in a variety of sectors, to select antibiotic resistance in Escherichia coli grown in biofilms. Biofilms were grown on inox coupons and then exposed daily to sublethal concentrations of PHMB over 10 days. Antibiotic-resistant variants were then isolated and characterized phenotypically and genotypically to identify the mechanisms of resistance. Repeated exposure to PHMB led to the selection of an E. coli variant (Ec04m1) with stable resistance to gentamycin (8-fold increase in minimum inhibitory concentration (MIC) compared to the parental strain. This was also associated with a significant decrease in the growth rate in the variant. Sequencing and comparison of the parental strain and Ec04m1 whole genomes revealed a nonsense mutation in the aceE gene in the variant. This gene encodes the pyruvate dehydrogenase E1 component of the pyruvate dehydrogenase (PDH) complex, which catalyzes the conversion of pyruvate to acetyl-CoA and CO2. A growth experiment in the presence of acetate confirmed the role of this mutation in a decreased susceptibility to both PHMB and gentamicin (GEN) in the variant. This work highlights the potential of PHMB to select resistance to antibiotics in bacteria, and that enzymes of central metabolic pathways should be considered as a potential target in adaptation strategies, leading to cross-resistance toward biocides and antibiotics in bacteria.

International audience; Aluminum (Al) can be ingested from food and released from packaging and can reach key organs involved in human metabolism, including the liver via systemic distribution. Recent studies discuss the occurrence of chemically distinct Al-species and their interconversion by contact with biological fluids. These Al species can vary with regard to their intestinal uptake, systemic transport, and therefore could have species-specific effects on different organs and tissues. This work aims to assess the in vitro hepatotoxic hazard potential of three different relevant Al species: soluble AlCl3 and two nanoparticulate Al species were applied, representing for the first time an investigation of metallic nanoparticles besides to mineral bound gamma-Al2O3 on hepatic cell lines. To investigate the uptake and toxicological properties of the Al species, we used two different human hepatic cell lines: HepG2 and differentiated HepaRG cells. Cellular uptake was determined by different methods including light microscopy, transmission electron microscopy, side-scatter analysis, and elemental analysis. Oxidative stress, mitochondrial dysfunction, cell death mechanisms, and DNA damage were monitored as cellular parameters. While cellular uptake into hepatic cell lines occurred predominantly in the particle form, only ionic AlCl3 caused cellular effects. Since it is known, that Al species can convert one into another, and mechanisms including 'trojan-horse'-like uptake can lead to an Al accumulation in the cells. This could result in the slow release of Al ions, for which reason further hazard cannot be excluded. Therefore, individual investigation of the different Al species is necessary to assess the toxicological potential of Al particles.

Objectives: Farm-level quantification of antimicrobial usage (AMU) in pig farms. Methods: In a cross-sectional study, AMU data on group treatments administered to a single batch of fattening pigs from birth to slaughter (group treatment data) and antimicrobials purchased during 1 year (purchase data) were collected at 180 pig farms in nine European countries. AMU was quantified using treatment incidence (TI) based on defined (DDDvet) and used (UDDvet) daily doses and defined (DCDvet) and used (UCDvet) course doses. Results: The majority of antimicrobial group treatments were administered to weaners (69.5% of total TIDDDvet) followed by sucklers (22.5% of total TIDDDvet). AMU varied considerably between farms with a median TIDDDvet of 9.2 and 7.1 for a standardized rearing period of 200 days based on group treatment and purchase data, respectively. In general, UDDvet and UCDvet were higher than DDDvet and DCDvet, respectively, suggesting that either the defined doses were set too low or that group treatments were often dosed too high and/or administered for too long. Extended-spectrum penicillins (31.2%) and polymyxins (24.7%) were the active substances most often used in group treatments, with the majority administered through feed or water (82%). Higher AMU at a young age was associated with higher use in older pigs. Conclusions: Collecting farm-level AMU data of good quality is challenging and results differ based on how data are collected (group treatment data versus purchase data) and reported (defined versus used daily and course doses).

International audience; Livestock data on antimicrobial resistance (AMR) are commonly collected from bacterial populations of clinical and non-clinical isolates. In contrast to data on non-clinical isolates from livestock, data on clinical isolates are not harmonized in Europe. The Normalized Resistance Interpretation (NRI) method was applied to overcome the lack of harmonization of laboratory methods and interpretation rules between monitoring systems. Statistical analyses were performed to identify associations between the isolate type (clinical vs. non-clinical) and resistance to four antimicrobials (ampicillin, tetracycline, gentamicin, and nalidixic acid) per animal category in Germany and France. Additional statistical analyses comparing clinical and non-clinical isolates were performed with the available data on the same antimicrobial panel and animal categories from the UK and Norway. Higher resistance prevalence was found in clinical isolates compared to non-clinical isolates from calves to all antimicrobials included in Germany and France. It was also found for gentamicin in broilers from France. In contrast, in broilers and turkeys from Germany and France and in broilers from the UK, a higher resistance level to ampicillin and tetracycline in non-clinical isolates was encountered. This was also found in resistance to gentamicin in isolates from turkeys in Germany. Resistance differed within countries and across years, which was partially in line with differences in antimicrobial use patterns. Differences in AMR between clinical and non-clinical isolates of Escherichia coli are associated with animal category (broiler, calf, and turkey) and specific antimicrobials. The NRI method allowed comparing results of non-harmonized AMR systems and might be useful until international harmonization is achieved.

Dans le cadre de la procédure d’évaluation des substances prévue par le Règlement REACH n°1907/2006 (articles 44 à 48), les États membres de l’Union européenne et des pays de l’Espace économique européen (à savoir la Norvège, l’Islande et le Liechtenstein ) évaluent chaque année les substances jugées prioritaires inscrites au plan d’action continu communautaire (CoRAP), en vue d’évaluer la ou les préoccupation(s) liées au processus defabrication et/ou à l’utilisation de ces substances et qui pourrai(en)t entrainer un risque pour la santé humaine et/ou pour l’environnement. Dans la majorité des cas, ces préoccupations initiales sont liées aux caractéristiques de danger des substances, associées ou renforcées par des caractéristiques d’exposition telles que : usages générant une forte dispersion des substances ou usages directs par les consommateurs.Les États membres peuvent cibler leur évaluation sur la préoccupation initiale, et peuvent aussi élargir leur évaluation à l’ensemble des propriétés de la substance.A l’issue des 12 mois d'évaluation par l’État membre évaluateur deux situations peuvent se présenter : a) des informations supplémentaires peuvent être demandées aux déclarants des substances, si ces données additionnelles sont jugées nécessaires pour lever un doute sur un danger suspecté. Dans ce cas, un projet de décision est discuté au sein du Comité des États-membres (CEM) de l’Agence européenne des produits chimiques (ECHA) ; b) il peut être conclu qu'aucune donnée supplémentaire n'est nécessaire. Dans ce cas, un document de conclusion est rédigé. Il peut alors être accompagné ou suivi d’une analyse des meilleures options de mesures de gestion réglementaires à mettre en œuvre le cas échéant.La liste de ces substances est énumérée dans le CoRAP (https://echa.europa.eu/informationon-chemicals/evaluation/community-rolling-action-plan/corap-table) ainsi qu’une courte description des préoccupations initiales pour chacune des substances qui seront évaluées.En 2014, l’ANSES a pris en charge l’évaluation de six substances, dont le méthacrylate de méthyle (N° EC 201-297-1, N° CAS 80-62-6)Le methacrylate de méthyle a été initialement inscrit au CoRAP en vue de son évaluation par la France sur la base des préoccupations suivantes :- l’existence d’effets sensibilisants,- une exposition des populations sensibles,- des usages par des consommateurs,- l’existence d’usages donnant lieu à une forte dispersion de la substance,- un important tonnage agrégé,- des ratios de risques élevés,Durant l’évaluation une préoccupation supplémentaire au regard de possibles effets mutagènes a été identifiée.L’évaluation de l’ANSES a couvert l’ensemble des effets sur la santé humaine et sur l’environnement.

Citation suggérée : Anses. (2021). Avis de l’Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail relatif à la « Pertinence de la ré-évaluation des risques sanitaires liés à la présence d’ions perchlorate dans les eaux destinées à la consommation humaine à la lumière des travaux de l’US EPA publiés le 23 mai 2019 ». (Saisine 2019-SA-0116). Maisons-Alfort : Anses, 82 p.; Depuis 2011, l’Anses a été saisie à plusieurs reprises sur les risques sanitaires liés aux ions perchlorate dans les eaux destinées à la consommation humaine (EDCH) suite à la mise en évidence de situations de contamination de ressources utilisées pour la production d’EDCH.En 2011, l’Agence avait préconisé une valeur guide (VG) pour les ions perchlorate dans les EDCH de 15 μg.L-1 pour le consommateur adulte, définie à partir de la valeur toxicologique de référence (VTR) de 0,7 μg.kg p.c.-1.j-1,fondée sur l’inhibition de la capture de l’iode par la thyroïde et conseillé de ne pas utiliser une eau contaminée par les ions perchlorate pour la préparation des biberons des nourrissons jusqu’à 6 mois.En 2012, dans son avis relatif aux études épidémiologiques portant sur les associations entre une exposition aux ions perchlorate dans les EDCH et la fonction thyroïdienne dans des populations spécifiques, l’Agence concluait que « les résultats des études épidémiologiques examinées par les experts ne permettent pas de conclure quant à l’existence ou à l’absence d’une association chez les femmes enceintes ou les nouveau-nés entre les niveaux de thyréostimuline (TSH, thyroid stimulating hormone) et des concentrations en ions perchlorate dans les eaux de boisson [...]. L’absence d’information concernant le statut en iode des populations étudiées rend difficile l’interprétation des données épidémiologiques publiées. »Dans son avis du 8 avril 2014 relatif à la présence d’ions perchlorate dans le lait infantile et dans les EDCH, l’Agence relevait les mêmes limites relatives aux études épidémiologiques disponibles et insistait sur la nécessité de prendre en compte le statut en iode de la population étudiée pour l’évaluation de l’impact sanitaire des ions perchlorate chez l’Homme et pourl’interprétation des données épidémiologiques publiées.Dans son dernier avis du 26 décembre 2018, l’Agence concluait que les études épidémiologiques récentes, y compris celle de de l’Institut de veille sanitaire (InVS) publiée en 2016, n’apportaient pas d’éléments conclusifs supplémentaires sur les effets biologiques ou cliniques des ions perchlorate par rapport à celles prises en compte dans les précédents avis de l’Anses (Anses 2011, 2012, 2014). Les données examinées dans cet avis n’étaient pas de nature à remettre en cause les conclusions des avis précédents de l’Anses, concernant la caractérisation des dangers et la VTR proposée en 2011 par l’Agence.Cependant, s’agissant de l’évaluation de l’exposition aux ions perchlorate, de nouvelles données ont permis d’estimer l’exposition moyenne de la population adulte aux ions perchlorate par voie orale. Cette estimation se fondait sur les données de contamination des aliments par les ions perchlorate (recueillies par la Direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF), dans le cadre de ses enquêtes nationales) et sur les données de contamination des EDCH pour la période 2014-2017 (produites par les Agences régionales de santé (ARS) et disponibles dans la base de données SISE-Eaux). Sur cette base, l’Anses estimait que la contribution de l’exposition liée à laconsommation d’EDCH représente environ 25% de l’exposition par ingestion. Cette estimation concordant avec les données de la littérature et se rapprochant du pourcentage de 20% défini par défaut par l’OMS en 2016, l’Agence considérait nécessaire d’abaisser la part de l’exposition hydrique alors fixée à 60%, pour le calcul de la VG des ions perchlorate dans lesEDCH pour les adultes. En conséquence, la VG proposée avait été abaissée à 5 μg.L-1 pour la population adulte.[Saisines liées 2011-SA-0024 ; 2011-SA-0208 ; 2011-SA-0336 ; 2012-SA-0119 ; 2016-SA-0155 et 2017-SA-0170]

Dans le cadre de la procédure d’évaluation des substances prévue par le Règlement REACH n°1907/2006 (articles 44 à 48), les États Membres évaluent chaque année des substances jugées prioritaires, dans le but de clarifier une ou des préoccupation(s) émanant de la fabrication et/ou de l’utilisation de ces substances et qui pourrai(en)t entrainer un risque pour la santé humaine et/ou pour l’environnement. Ces substances sont inscrites sur le plan d’action continu communautaire (CoRAP), publié sur le site internet de l’Agence européenne des produits chimiques (ECHA) avec une courte description des préoccupations initialement identifiées pour chacune des substances. Dans la majorité des cas, ces préoccupations initiales sont liées aux propriétés de danger potentiel, en combinaison avec une utilisation susceptible de conduire à une dispersion environnementale ou des usages générant une exposition pour les consommateurs.Chaque année, les États membres de l’Union européenne et des pays de l’Espace économique européen (à savoir la Norvège, l'Islande et le Liechtenstein) évaluent les substances inscrites au CoRAP dans le but de clarifier la ou les préoccupation(s) initiale(s) émanant de la fabrication et/ou l’utilisation de ces substances et qui pourraient représenter un risque pour la santé humaine et/ou pour l’environnement. Le CoRAP en 2018 incluait deux substances dont l’évaluation a été confiée à l’Anses.Les États membres peuvent cibler leur évaluation sur la préoccupation initiale, mais peuvent aussi l’élargir à tout ou partie des propriétés de la substance. A l’issue des 12 mois d'évaluation, l’État membre évaluateur peut demander des informations supplémentaires aux déclarants des substances, si ces données additionnelles sont jugées nécessaires pour clarifier une ou des préoccupation(s). Dans ce cas, un projet de décision est soumis aux États membres et aux déclarants pour commentaires, puis ce projet de décision peut être discuté au Comité des États Membres (CEM) de l’ECHA en cas d’avis divergents entre les États membres. Alternativement, il peut être conclu qu'aucune donnée supplémentaire n'est nécessaire pour clarifier le risque. Dans ce cas, un document de conclusion est rédigé. Le cas échéant, si des préoccupations sont confirmées, la rédaction d’une analyse de la meilleure option de gestion des risques (RMOA) peut être proposée.Les quatre substances évaluées en 2019 par la France ont été les suivantes: - Oxyde de chrome III (n°CAS 1308-38-9) - Resorcinol (n°CAS 108-46-3) - Triclocarban (n°CAS 101-20-2) - 6,6'-di-tert-butyl-4,4'-butylidenedi-m-cresol (n°CAS 85-60-9)(reproduction d'un tableau non intégré sur cette notice)Ces quatre substances sont enregistrées auprès de l’ECHA dans le cadre de l’application du règlement REACH, ce qui signifie que des industriels ont déposé des dossiers d’enregistrement contenant les données requises en fonction de leur bande de tonnage de production et/ou d’importation.Le présent avis a pour objet de résumer les principales étapes de l’analyse des deux substances évaluées par l’Anses en 2019 et les décisions ou conclusions issues de cette expertise.[Saisines associées : 2019-SA-0071, 2019-SA- 0069 et 2019-SA-0187]

International audience; The detection of antimicrobial residues in food products of animal origin is of utmost importance. Indeed antimicrobial residues could be present in animal derived food products because of animal treatments for curative purposes or from illegal use. The usual screening methods to detect antimicrobial residues in food are microbiological, immunological or physico-chemical methods. The development of biosensors to propose sensitive, cheap and quick alternatives to classical methods is constantly increasing. Aptasensors are one of the major trends proposed in the literature, in parallel with the development of immunosensors based on antibodies. The characteristics of electrochemical sensors (i.e., low cost, miniaturization, and portable instrumentation) make them very good candidates to develop screening methods for antimicrobial residues in food products. This review will focus on the recent advances in the development of electrochemical aptasensors for the detection of antimicrobial residues in food products. The contribution of nanomaterials to improve the performance characteristics of electrochemical aptasensors (e.g., Sensitivity, easiness, stability) in the last ten years, as well as signal amplification techniques will be highlighted.

Surface-associated multicellular assemblage is an important bacterial trait to withstand harsh environmental conditions. Bacillus subtilis is one of the most studied Gram-positive bacteria, serving as a model for the study of genetic pathways involved in the different steps of 3D biofilm formation. B. subtilis biofilm studies have mainly focused on pellicle formation at the air-liquid interface or complex macrocolonies formed on nutritive agar. However, only few studies focus on the genetic features of B. subtilis submerged biofilm formation and their link with other multicellular models at the air interface. NDmed, an undomesticated B. subtilis strain isolated from a hospital, has demonstrated the ability to produce highly structured immersed biofilms when compared to strains classically used for studying B. subtilis biofilms. In this contribution, we have conducted a multi-culturing comparison (between macrocolony, swarming, pellicle, and submerged biofilm) of B. subtilis multicellular communities using the NDmed strain and mutated derivatives for genes shown to be required for motility and biofilm formation in pellicle and macrocolony models. For the 15 mutated NDmed strains studied, all showed an altered phenotype for at least one of the different culture laboratory assays. Mutation of genes involved in matrix production (i.e., tasA, epsA-O, cap, ypqP) caused a negative impact on all biofilm phenotypes but favored swarming motility on semi-solid surfaces. Mutation of bslA, a gene coding for an amphiphilic protein, affected the stability of the pellicle at the air-liquid interface with no impact on the submerged biofilm model. Moreover, mutation of lytF, an autolysin gene required for cell separation, had a greater effect on the submerged biofilm model than that formed at aerial level, opposite to the observation for lytABC mutant. In addition, B. subtilis NDmed with sinR mutation formed wrinkled macrocolony, less than that formed by the wild type, but was unable to form neither thick pellicle nor structured submerged biofilm. The results are discussed in terms of the relevancy to determine whether genes involved in colony and pellicle formation also govern submerged biofilm formation, by regarding the specificities in each model.

L’ANSES a été saisie le 10 juillet 2018 par la Direction générale de l’alimentation (DGAL), la Direction générale de la santé (DGS) et la Direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF) pour la réalisation de l’expertise suivante : saisine de l’ANSES relative aux valeurs sanitaires de références pour le chlordécone.Dans le cadre du plan Chlordécone 3 (2014-2020), l’ANSES et Santé Publique France (SPF) ont été mobilisées pour réévaluer les risques et les niveaux d’exposition de la population antillaise afin d’adapter les mesures de gestion.L’ANSES a publié un avis en décembre 2017 relatif à l’actualisation des données d’exposition par voie alimentaire afin d’évaluer les risques des populations antillaises et émettre des recommandations de consommation dans le cadre du projet KANNARI « Santé, nutrition et exposition au chlordécone aux Antilles » (ANSES 2017).Pour formuler cet avis, l'ANSES avait mené une analyse des études scientifiques parues depuis 2007 et jusqu'en 2014 (9 études épidémiologiques et 13 études toxicologiques chez l’animal citées en annexe 2 de l'avis du 6 décembre 2017) : elle avait conclu que les étudestoxicologiques publiées depuis l'établissement des valeurs toxicologiques de référence (VTR) en 2003 ne remettaient pas en cause celles-ci.Il est rappelé que 2 valeurs toxicologiques de référence (VTR) externes ont été définies en 2003 (AFSSA 2003): une VTR chronique de 0,5 µg/kg de poids corporel/j ; une VTR aiguë de 10 µg/kg pc/j.Par ailleurs, dans le cadre de la publication du volet imprégnation de l'étude KANNARI par SPF et aussi compte-tenu du contexte de fortes inquiétudes de la population antillaise au regard des données d’exposition interne il est apparu nécessaire aux ministères de tutelle depouvoir disposer d’une VTR interne afin d'interpréter ces données. Dans le cadre de la préparation de la restitution des travaux de SPF et de l'ANSES aux agences régionales de santé, aux préfectures et à leurs services, le 13 juin 2018, ainsi qu'au comité de pilotage du plan Chlordécone du 20 juin 2018, les deux agences (ANSES et SPF) ont proposé que soit conduite une expertise pluridisciplinaire afin de définir une VTR interne et, à cette occasion, de réexaminer les VTR (externes), permettant à la fois d'assurer la cohérence des valeurs sanitaires de référence utilisées pour interpréter les deux volets de l'étude KANNARI, de les fonder sur une revue de littérature couvrant des périodes identiques, et de prendre en compte les données scientifiques les plus récentes comme le recours à un modèle pharmacocinétique à base physiologique (PBPK). Á cet égard, la saisine avait rappelé « l'importance du projet PK-chlor Antilles sur cette question qui permettra de développer un modèle prédictif PBPK afin d'estimer des doses d'exposition externes à partir de doses internes (sang) ». Ce modèle avait vocation à être mobilisé pour estimer une VTR à partir de données d’exposition interne existantes chez l’Homme. Il est demandé à l’ANSES de mener une expertise afin de définir une VTR interne et, à cette occasion de réexaminer les VTR externes, notamment en complétant les analyses antérieures par la prise en compte des nouvelles études épidémiologiques concernant l'exposition interne globale des populations. L’expertise doit porter sur l’ensemble des études épidémiologiques et toxicologiques postérieures à celles considérées dans l’élaboration des VTR publiées en 2003. L’ANSES devra aussi se rapprocher de l'Inserm chargé de la coordination du projet PKchlor Antilles. Ce travail sera mené en lien étroit avec SPF, notamment pour la définition d'une VTR interne pour le chlordécone.Si les VTR devaient être modifiées, il serait demandé à l’ANSES de reconsidérer ses précédentes recommandations toujours dans l’optique de poursuivre l'objectif de réduction de l'exposition de la population antillaise au chlordécone, en particulier pour les populations les plus vulnérables.Concernant la VTR aiguë, elle n’a pas été modifiée par l’ATSDR dans sa plus récente évaluation du chlordécone (ATSDR 2019, 2020). Le GT note que, selon les informations à disposition, le chlordécone n’est plus fabriqué, ni autorisé en tant que produits phytopharmaceutiques depuis de nombreuses années (1993) ; en conséquence, l’exposition aiguë chez l’Homme est très peu probable aujourd’hui et ne sera pas développée dans ce rapport.Le présent avis porte sur la mise à jour de la VTR chronique externe et sur l’établissement d’une VTR chronique interne. Les conclusions à tirer en matière d’adaptation des recommandations, seront transmises ultérieurement aux tutelles au travers d’un autre avis.

L’ANSES a été saisie le 10 juillet 2018 par la Direction générale de l’alimentation (DGAL), la Direction générale de la santé (DGS) et la Direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF) pour la réalisation de l’expertise suivante : saisine de l’ANSES relative aux valeurs sanitaires de références pour le chlordécone.Dans le cadre du plan Chlordécone 3 (2014-2020), l’ANSES et Santé Publique France (SPF) ont été mobilisées pour réévaluer les risques et les niveaux d’exposition de la population antillaise afin d’adapter les mesures de gestion.L’ANSES a publié un avis en décembre 2017 relatif à l’actualisation des données d’exposition par voie alimentaire afin d’évaluer les risques des populations antillaises et émettre des recommandations de consommation dans le cadre du projet KANNARI « Santé, nutrition et exposition au chlordécone aux Antilles » (ANSES 2017).Pour formuler cet avis, l'ANSES avait mené une analyse des études scientifiques parues depuis 2007 et jusqu'en 2014 (9 études épidémiologiques et 13 études toxicologiques chez l’animal citées en annexe 2 de l'avis du 6 décembre 2017) : elle avait conclu que les étudestoxicologiques publiées depuis l'établissement des valeurs toxicologiques de référence (VTR) en 2003 ne remettaient pas en cause celles-ci.Il est rappelé que 2 valeurs toxicologiques de référence (VTR) externes ont été définies en 2003 (AFSSA 2003): une VTR chronique de 0,5 µg/kg de poids corporel/j ; une VTR aiguë de 10 µg/kg pc/j.Par ailleurs, dans le cadre de la publication du volet imprégnation de l'étude KANNARI par SPF et aussi compte-tenu du contexte de fortes inquiétudes de la population antillaise au regard des données d’exposition interne il est apparu nécessaire aux ministères de tutelle depouvoir disposer d’une VTR interne afin d'interpréter ces données. Dans le cadre de la préparation de la restitution des travaux de SPF et de l'ANSES aux agences régionales de santé, aux préfectures et à leurs services, le 13 juin 2018, ainsi qu'au comité de pilotage du plan Chlordécone du 20 juin 2018, les deux agences (ANSES et SPF) ont proposé que soit conduite une expertise pluridisciplinaire afin de définir une VTR interne et, à cette occasion, de réexaminer les VTR (externes), permettant à la fois d'assurer la cohérence des valeurs sanitaires de référence utilisées pour interpréter les deux volets de l'étude KANNARI, de les fonder sur une revue de littérature couvrant des périodes identiques, et de prendre en compte les données scientifiques les plus récentes comme le recours à un modèle pharmacocinétique à base physiologique (PBPK). Á cet égard, la saisine avait rappelé « l'importance du projet PK-chlor Antilles sur cette question qui permettra de développer un modèle prédictif PBPK afin d'estimer des doses d'exposition externes à partir de doses internes (sang) ». Ce modèle avait vocation à être mobilisé pour estimer une VTR à partir de données d’exposition interne existantes chez l’Homme. Il est demandé à l’ANSES de mener une expertise afin de définir une VTR interne et, à cette occasion de réexaminer les VTR externes, notamment en complétant les analyses antérieures par la prise en compte des nouvelles études épidémiologiques concernant l'exposition interne globale des populations. L’expertise doit porter sur l’ensemble des études épidémiologiques et toxicologiques postérieures à celles considérées dans l’élaboration des VTR publiées en 2003. L’ANSES devra aussi se rapprocher de l'Inserm chargé de la coordination du projet PKchlor Antilles. Ce travail sera mené en lien étroit avec SPF, notamment pour la définition d'une VTR interne pour le chlordécone.Si les VTR devaient être modifiées, il serait demandé à l’ANSES de reconsidérer ses précédentes recommandations toujours dans l’optique de poursuivre l'objectif de réduction de l'exposition de la population antillaise au chlordécone, en particulier pour les populations les plus vulnérables.Concernant la VTR aiguë, elle n’a pas été modifiée par l’ATSDR dans sa plus récente évaluation du chlordécone (ATSDR 2019, 2020). Le GT note que, selon les informations à disposition, le chlordécone n’est plus fabriqué, ni autorisé en tant que produits phytopharmaceutiques depuis de nombreuses années (1993) ; en conséquence, l’exposition aiguë chez l’Homme est très peu probable aujourd’hui et ne sera pas développée dans ce rapport.Le présent avis porte sur la mise à jour de la VTR chronique externe et sur l’établissement d’une VTR chronique interne. Les conclusions à tirer en matière d’adaptation des recommandations, seront transmises ultérieurement aux tutelles au travers d’un autre avis.

By 2010, systems set up to monitor the antimicrobial resistance of pathogenic bacteria and antimicrobial usage identified a sustained increase regarding third‐ and fourth‐generation cephalosporin resistance in French pig production. This sector mobilised and collectively committed to responsible action in the following months. This led to a multi‐professional voluntary stewardship programme that was started in 2011. A consensus of veterinary opinion led to the definition of restrictive rules on the prescription of the third‐ and fourth‐generation cephalosporins targeted by the antimicrobial stewardship programme (ASP). All pig sector professionals, including farmers, were informed. Existing monitoring systems for usage and resistance were supplemented by data from the records of veterinarians' cephalosporin deliveries and from individual pig farm surveys investigating antimicrobial usage. The second step, from 2014, entailed regulatory measures that consolidated the programme by setting quantitative reduction objectives and specifying the terms and conditions for prescribing and dispensing a list of critical antimicrobial molecules including cephalosporins. All the data sources confirmed a significant fall of more than 90% in cephalosporin usage in the French pig production sector between 2010 and 2016. Monitoring systems recorded that the resistance of commensal and pathogenic Escherichia coli isolates also tended to decrease over the same period. The stewardship programme proved highly effective in reducing usage and containing resistance, illustrating the efficiency of a well‐defined multi‐professional strategy., This study details success conditions of an antimicrobial stewardship program in animal agriculture. Based on data provided by complementary and independent monitoring tools, success could be assessed on both usage and resistance. Results highlight the strong relationship between cephalosporins usage and resistance in pig production, supporting a containment perspective through usage restriction.

One Health European Joint Programme is acknowledged for the funding of the ListAdapt project and the support of A.G.’s postdoctoral fellowship. Laurent Guillier is acknowledged for his participation in the supervision of the ListAdapt project.; International audience; In this contribution, the antimicrobial susceptibility toward 11 antibiotics and four biocides of a panel of 205 Listeria monocytogenes (Lm) strains isolated from different ecological niches (i.e., food, animals and natural environment) was evaluated. The impact of exposure to biocides on the antibiotic susceptibilities of Lm was also investigated. Lm strains isolated from food exhibited overall a lower susceptibility (higher minimal inhibitory concentrations, MIC) for ammonium quaternary compounds (QACs) and peracetic acid (PAC) than strains isolated from animals and natural environments. Conversely, the ecological origins of Lm strains did not significantly affect their susceptibilities towards antibiotics. Interestingly, repeated exposure to QACs recurrently led to a decrease in susceptibility toward ciprofloxacin (CIP), a fluoroquinolone antibiotic, largely used in human medicine. Moreover, these lower levels of susceptibility to CIP remained stable in most Lm strains even after subcultures without biocide selection pressure, suggesting an adaptation involving modifications at the genetic level. Results underlined the ability of Lm to adapt to biocides, especially QACs, and the potential link between this adaptation and the selection of resistance toward critical antibiotics such as ciprofloxacin. These data support a potential role of the extensive use of QACs from “farm to fork” in the selection of biocide and antibiotic resistance in pathogenic bacteria such as Lm.

International audience; In response to the massive use of biocides for controlling Listeria monocytogenes (hereafter Lm) contaminations along the food chain, strains showing biocide tolerance emerged. Here, accessory genomic elements were associated with biocide tolerance through pangenome-wide associations performed on 197 Lm strains from different lineages, ecological, geographical and temporal origins. Mobile elements, including prophage-related loci, the Tn6188_qacH transposon and pLMST6_emrC plasmid, were widespread across lineage I and II food strains and associated with tolerance to benzalkonium-chloride (BC), a quaternary ammonium compound (QAC) widely used in food processing. The pLMST6_emrC was also associated with tolerance to another QAC, the didecyldimethylammonium-chloride, displaying a pleiotropic effect. While no associations were detected for chemically reactive biocides (alcohols and chlorines), genes encoding for cell-surface proteins were associated with BC or polymeric biguanide tolerance. The latter was restricted to lineage I strains from animal and the environment. In conclusion, different genetic markers, with polygenic nature or not, appear to have driven the Lm adaptation to biocide, especially in food strains but also from animal and the environment. These markers could aid to monitor and predict the spread of biocide tolerant Lm genotypes across different ecological niches, finally reducing the risk of such strains in food industrial settings.

Microcystins (MCs) are toxins produced by several cyanobacterial species found worldwide. While MCs have a common structure, the variation of two amino acids in their structure affects their toxicity. As toxicodynamics are very similar between the MC variants, their differential toxicity could rather be explained by toxicokinetic parameters. Microcystin-RR (MC-RR) is the second most abundant congener and induces toxicity through oral exposure. As intestinal permeability is a key parameter of oral toxicokinetics, the apparent permeability of MC-RR across a differentiated intestinal Caco-2 cell monolayer was investigated. We observed a rapid and large decrease of MC-RR levels in the donor compartment. However, irrespective of the loaded concentration and exposure time, the permeabilities were very low from apical to basolateral compartments (from 4 to 15 × 10−8 cm·s−1) and from basolateral to apical compartments (from 2 to 37 × 10−8 cm·s−1). Our results suggested that MC-RR would be poorly absorbed orally. As similar low permeability was reported for the most abundant congener microcystin-LR, and this variant presented a greater acute oral toxicity than MC-RR, we concluded that the intestinal permeability was probably not involved in the differential toxicity between them, in contrast to the hepatic uptake and metabolism.

National audience; In the framework of extended-spectrum cephalosporin- or carbapenem-resistant Escherichia coli (E. coli) surveillance in retail meat in France, no carbapenem-resistant isolates were detected from 1935 samples of broiler chickens, pork and beef between 2016 and 2019. The proportions of extended-spectrum β-lactamases- or cephalosporinase (ESBL/AmpC)-producing E. coli were low and stable in pork [0.3-1.2%] and beef [0.3-0.6%] from 2017 to 2019. However, 62% of poultry meat in 2016 was positive for ESBL/AmpC-producing E. coli, although this proportion dropped significantly to 26% in 2018 (Chi², p