Crepet A.,French Agency for Food |
Tressou J.,French National Institute for Agricultural Research
Bayesian Analysis | Year: 2011
This work introduces a specific application of Bayesian nonparametric statistics to the food risk analysis framework. The goal was to determine the cocktails of pesticide residues to which the French population is simultaneously exposed through its current diet in order to study their possible combined effects on health through toxicological experiments. To do this, the joint distribution of exposures to a large number of pesticides, which we called the co-exposure distribution, was assessed from the available consumption data and food contamination analyses. We propose modelling the co-exposure using a Dirichlet process mixture based on a multivariate Gaussian kernel so as to determine groups of individuals with similar co-exposure patterns. Posterior distributions and optimal partition were computed through a Gibbs sampler based on stick-breaking priors. The study of the correlation matrix of the sub-population co-exposures will be used to define the cocktails of pesticides to which they are jointly exposed at high doses. To reduce the computational burden due to the high data dimensionality, a random-block sampling approach was used. In addition, we propose to account for the uncertainty of food contamination through the introduction of an additional level of hierarchy in the model. The results of both specifications are described and compared. © 2011 International Society for Bayesian Analysis.
Carpentier B.,French Agency for Food |
Cerf O.,National Veterinary School of Alfort
International Journal of Food Microbiology | Year: 2011
To understand why Listeria monocytogenes may persist in food industry equipment and premises, notably at low temperature, scientific studies have so far focused on adhesion potential, biofilm forming ability, resistance to desiccation, acid and heat, tolerance to increased sublethal concentration of disinfectants or resistance to lethal concentrations. Evidence from studies in processing plants shows that the factors associated with the presence of L. monocytogenes are those that favor growth. Interestingly, most conditions promoting bacterial growth were shown, in laboratory assays, to decrease adhesion of L. monocytogenes cells. Good growth conditions can be found in so-called harborage sites, i.e. shelters due to unhygienic design of equipment and premises or unhygienic or damaged materials. These sites are hard to eliminate. A conceptual model of persistence/no persistence based on the relative weight of growth vs. outcome of cleaning and disinfection is suggested. It shows that a minimum initial bacterial load is necessary for bacteria to persist in a harborage site and that when a low initial bacterial charge is applied, early cleaning and disinfection is the only way to avoid persistence. We conclude by proposing that there are no strains of L. monocytogenes with unique properties that lead to persistence, but harborage sites in food industry premises and equipment where L. monocytogenes can persist. © 2011 Elsevier B.V.
Zeitouni S.,French Agency for Food |
Kempf I.,French Agency for Food
Microbial Drug Resistance | Year: 2011
In this study, the fitness cost of fluoroquinolone resistance was evaluated in vitro, on food matrices, and in vivo, using Campylobacter coli and Campylobacter jejuni in vitro selected mutants. In vitro, the growth rate of the susceptible (wild type) and resistant (mutant) strains did not differ when cultured separately. However, by conducting sequential passages of mixed cultures, the ratio of the resistant mutant to the susceptible strain decreased for C. coli but not for C. jejuni. When the wild type and the mutant were co-inoculated on food matrices, mutants were no longer detectable 3 to 5 days after artificial contamination, but the wild-type strains remained detectable for over 13 days. In mono-inoculated animals, no difference was observed between wild-type and mutant fecal titers. When co-inoculated into chickens, the susceptible strain outcompeted the resistant mutant for C. coli and for C. jejuni. However, for C. coli, if the resistant strain was already present in animals, it could persist at high titers in the digestive tract even in the presence of the wild-type strain. Together, these findings suggest that, depending on strain and study conditions, fluoroquinolone resistance can impose a fitness cost on Campylobacter. © 2011, Mary Ann Liebert, Inc.
Sirot V.,French Agency for Food |
Fremy J.-M.,French Agency for Food |
Leblanc J.-C.,French Agency for Food
Food and Chemical Toxicology | Year: 2013
Mycotoxins are produced in plants by micro-fungi species, and naturally contaminated the food chain. In the second French total diet study (TDS), mycotoxins were analyzed in 577 food samples collected in mainland France to be representative of the population diet and prepared 〈〈as consumed〉〉. Highest mean concentrations were found in wheat and cereal-based products (bread, breakfast cereals, pasta, pastries, pizzas and savoury pastries...). Exposure of adult and child populations was assessed by combining national consumption data with analytical results, using lowerbound (LB) and upperbound (UB) assumptions for left-censorship management. Individual exposures were compared with available health-based guidance values (HBGV). Only the exposure to deoxynivalenol (DON) and its acetylated derivatives was found to significantly exceed the HBGV in LB in adults (0.5% [0.1; 0.8]) and children (5% [4; 6]). HBGV was exceeded in UB only for T-2 and HT-2 toxins by, respectively, 0.2% [0.02; 0.05] and 4% [3; 5] of adults, and 11% [9; 12] and 35% [32; 37] of children. Although the exposures assessed were generally lower than the previous French TDS, the results indicated a health concern for trichothecenes and a need to reduce dietary exposure as well as analytical limits. © 2012 Elsevier Ltd.
Sirot V.,French Agency for Food |
Leblanc J.-C.,French Agency for Food |
Margaritis I.,French Agency for Food
British Journal of Nutrition | Year: 2012
Seafood provides n-3 long-chain PUFA (n-3 LC-PUFA), vitamins and minerals, which are essential to maintain good health. Moreover, seafood is a source of contaminants such as methylmercury, arsenic and persistent organic pollutants that may affect health. The aim of the present study was to determine in what quantities seafood consumption would provide nutritional benefits, while minimising the risks linked to food contaminants. Seafood was grouped into clusters using a hierarchical cluster analysis. Those nutrients and contaminants were selected for which it is known that seafood is a major source. The risk-benefit analysis consisted in using an optimisation model with constraints to calculate optimum seafood cluster consumption levels. The goal was to optimise nutrient intakes as well as to limit contaminant exposure with the condition being to attain recommended nutritional intakes without exceeding tolerable upper intakes for contaminants and nutrients, while taking into account background intakes. An optimum consumption level was calculated for adults that minimises inorganic arsenic exposure and increases vitamin D intake in the general population. This consumption level guarantees that the consumer reaches the recommended intake for n-3 LC-PUFA, Se and I, while remaining below the tolerable upper intakes for methylmercury, Cd, dioxins, polychlorobiphenyls, Zn, Ca and Cu. This consumption level, which is approximately 200 g/week of certain fatty fish species and approximately 50 g/week of lean fish, molluscs and crustaceans, has to be considered in order to determine food consumption recommendations in a public health perspective. © 2011 The Authors.
Cliquet F.,French Agency for Food |
Picard-Meyer E.,French Agency for Food |
Robardet E.,French Agency for Food
Expert Review of Anti-Infective Therapy | Year: 2014
Rabies remains a serious endemic disease in animal populations in many European countries. Oral vaccination by use of rabies vaccine baits has proved to be durably efficient for controlling and eliminating terrestrial rabies. However, the recurrence of rabies in some countries highlights the fragility of rabies-free country status and the need for continuous surveillance. In Eastern and Southern countries, the rabies control programmes for foxes should be accompanied by stray dog management measures in view of the high populations of strays in certain areas. Alerts of rabies in pets imported from enzootic countries are regularly reported in Europe, threatening the rabies-free status of terrestrial animals. New variants of rabies virus have been recently discovered in autochthonous bats, implying research studies to assess the efficacy of the current vaccines against those strains and the possible crossing of the species barrier in terrestrial mammals. The incidence of the disease in humans is very low, with cases contracted in Europe or in enzootic countries. Sustainable strategies of vaccination programmes in animals and improvement of public awareness, particularly for travelers, regarding rabies risks and legislation for pet movements would render accessible the elimination of rabies in Europe. © Informa UK, Ltd.
Pavio N.,French Agency for Food |
Merbah T.,French Agency for Food |
Thebault A.,French Agency for Food
Emerging Infectious Diseases | Year: 2014
Food products containing raw pork liver are suspected to be vehicles for transmission of hepatitis E virus. Four categories of food products, comprising 394 samples, were analyzed to determine hepatitis E virus prevalence. Virus was detected in 3%–30% of the different categories. Phylogenetic analysis showed high identity with human and swine sequences. © 2014, Centers for Disease Control and Prevention (CDC). All Right Resrved.
Hurtaud-Pessel D.,French Agency for Food |
Couedor P.,French Agency for Food |
Verdon E.,French Agency for Food
Journal of Chromatography A | Year: 2011
A method is described for the identification and the quantitative determination of the triphenylmethane dyes, malachite green (MG), crystal violet (CV), brilliant green (BG) and leuco malachite green (LMG) and leuco crystal violet (LCV). The analytes were isolated from the matrix by liquid-liquid extraction with acetonitrile. Determination was performed using LC-MS/MS with positive electrospray ionisation. 4 different deuterated internal standards were introduced to improve the quantitative performance of the method. The method has been validated in line with the EU criteria of Commission Decision 2002/657/EC in accordance with the minimum required performance limit (MRPL) set at 2μgkg-1 for the sum of MG and LMG. For all the monitored compounds, accuracy, intra-day and inter-day precision were determined at each level of fortification (0.5, 0.75, 1.0 and 2.0μgkg-1). Decision limits CCα and detection capabilities CCβ were calculated according to the standard ISO 11843-2. A study on the applicability of the method was conducted on various aquacultured species with the aim to assess the matrix effects. The presence of residues of leuco brilliant green in fish has also been confirmed from experimental study performed on trout treated with brilliant green, using LTQ-Orbitrap mass spectrometer. © 2011 Elsevier B.V.
Lombard B.,French Agency for Food
Accreditation and Quality Assurance | Year: 2012
The contribution of reference laboratories in the European Union and of European/international standardization to the reliability of food microbiology measurement results is discussed. A set of European Union reference laboratories has been established. Each of them coordinates a network of national reference laboratories which, in turn, coordinate networks of laboratories in charge of official testing and sometimes own checks in each European Union country. Their contribution to the reliability of food microbiology measurement results is illustrated by three food safety cases: Listeria monocytogenes, coagulase positive staphylococci and milk/milk products. The contribution of European/international standardization focuses on two topics: method validation and measurement uncertainty. The standards covering these topics-EN ISO 16140 and ISO/TS 19036-are briefly discussed, and an update given on their ongoing revision. © 2012 Springer-Verlag.
Cliquet F.,French Agency for Food
PLoS neglected tropical diseases | Year: 2012
The compulsory vaccination of pets, the recommended vaccination of farm animals in grazing areas and the extermination of stray animals did not succeed in eliminating rabies in Estonia because the virus was maintained in two main wildlife reservoirs, foxes and raccoon dogs. These two species became a priority target therefore in order to control rabies. Supported by the European Community, successive oral vaccination (OV) campaigns were conducted twice a year using Rabigen® SAG2 baits, beginning in autumn 2005 in North Estonia. They were then extended to the whole territory from spring 2006. Following the vaccination campaigns, the incidence of rabies cases dramatically decreased, with 266 cases in 2005, 114 in 2006, four in 2007 and three in 2008. Since March 2008, no rabies cases have been detected in Estonia other than three cases reported in summer 2009 and one case in January 2011, all in areas close to the South-Eastern border with Russia. The bait uptake was satisfactory, with tetracycline positivity rates ranging from 85% to 93% in foxes and from 82% to 88% in raccoon dogs. Immunisation rates evaluated by ELISA ranged from 34% to 55% in foxes and from 38% to 55% in raccoon dogs. The rabies situation in Estonia was compared to that of the other two Baltic States, Latvia and Lithuania. Despite regular OV campaigns conducted throughout their territory since 2006, and an improvement in the epidemiological situation, rabies has still not been eradicated in these countries. An analysis of the number of baits distributed and the funding allocated by the European Commission showed that the strategy for rabies control is more cost-effective in Estonia than in Latvia and Lithuania.