Augustin J.-C.,National Veterinary School of Alfort |
Bergis H.,Agence Francaise de Securite Sanitaire des Aliments AFSSA |
Midelet-Bourdin G.,Agence Francaise de Securite Sanitaire des Aliments AFSSA |
Cornu M.,Agence Francaise de Securite Sanitaire des Aliments AFSSA |
And 8 more authors.
Food Microbiology | Year: 2011
The assessment of the evolution of micro-organisms naturally contaminating food must take into account the variability of biological factors, food characteristics and storage conditions. A research project involving eight French laboratories was conducted to quantify the variability of growth parameters of Listeria monocytogenes obtained by challenge testing in five food products. The residual variability corresponded to a coefficient of variation (CV) of approximately 20% for the growth rate (μmax) and 130% for the parameter K = μmax × lag. The between-batch and between-manufacturer variability of μmax was very dependent on the food tested and mean CV of approximately 20 and 35% were observed for these two sources of variability, respectively. The initial physiological state variability led to a CV of 100% for the parameter K. It appeared that repeating a limited number of three challenge tests with three different batches (or manufacturers) and with different initial physiological states seems often necessary and adequate to accurately assess the variability of the behavior of L. monocytogenes in a specific food produced by a given manufacturer (or for a more general food designation). © 2010 Elsevier Ltd. Source
Coton E.,ADRIA NORMANDIE |
Desmonts M.-H.,AERIAL |
Leroy S.,French National Institute for Agricultural Research |
Coton M.,ADRIA NORMANDIE |
And 5 more authors.
International Journal of Food Microbiology | Year: 2010
In this study, the biodiversity of Coagulase-Negative Staphylococci (CNS) strains isolated in France from cheese related samples (227 isolates) and dry sausage related samples (204 isolates) was compared to the biodiversity of 297 clinical isolates. Species identification was performed using different molecular methods (specific PCR, "Staph array" hybridization and sodA gene sequencing). Infraspecific biodiversity of strains belonging to the main CNS species found in both food and clinical samples was then assessed by pulse-field gel electrophoresis (PFGE). For food-related samples, the main species encountered corresponded to Staphylococcus equorum (28.5%), S. xylosus (28.3%), S. saprophyticus (12.5%) and S. succinus (7.7%); while, for clinical isolates, the main species encountered corresponded to S. epidermidis (69.4%), S. capitis (9.8%), S. hominis (4.5%), S. warneri (4.5%) and S. haemolyticus (3.8%). The two main species common to both food and clinical samples corresponded to S. epidermidis and S. saprophyticus. Concerning infraspecific biodiversity, PFGE profiles of S. equorum, S. saprophyticus and S. epidermidis showed a large genomic biodiversity. Comparatively, S. xylosus exhibited a lower biodiversity. No correlation could be observed between PFGE patterns and either the geographical origin or the sample type. This study highlighted that no food strains had similar PFGE profiles to clinical ones and that the two main food-related species, S. equorum and S. xylosus, were not found in clinical samples. The identification of CNS species and the characterisation of the genetic diversity of the strains constitute a first step towards CNS safety assessment. © 2009 Elsevier B.V. All rights reserved. Source
Agency: Cordis | Branch: FP7 | Program: CSA | Phase: ICT-2011.3.2 | Award Amount: 1.13M | Year: 2011
The overall objective of FoodMicroSystems is to initiate the implementation of microsystems & smart miniaturised systems in the food sector by improving cooperation between suppliers and users of microsystems for food/beverage quality and safety. The project has five specific objectives:\n\n1.\tTo improve the coordination of national and EU programmes for the development of food applications\n2.\tTo facilitate cooperation of the value chain actors from research to industrialisation of smart systems in the food sector\n3.\tTo promote industrial take-up actions in the food sector\n4.\tTo develop roadmaps linking applications and technologies\n5.\tTo promote international cooperation\n\nThe project is structured into 5 main work- packages (WPs). WP1 (Current state of play) will identify partners for international cooperation as well as examples of existing MST applications in the food sector. WP2 (Research inventory) will provide an analysis of MST research programmes and activities in regards to food applications. WP3 (Food industry demands and constraints) will study the needs of the food industry, the economic and technical constraints, the perception of the consumers as well as the ethical and regulation context. WP4 (Roadmapping) will develop detailed research and application roadmaps for three food chains. WP5 (Communication and exploitation) aims at communicating the projects results through dissemination, presentations, information campaigns and training.\n\nThe consortium includes key research players in both the food and the microsystems sectors. FoodMicroSystems is an open project that will associate industry and other stakeholders in its activities.
Coton M.,ADRIA NORMANDIE |
Delbes-Paus C.,French National Institute for Agricultural Research |
Irlinger F.,French National Institute for Agricultural Research |
Desmasures N.,University of Caen Lower Normandy |
And 4 more authors.
Food Microbiology | Year: 2012
The goal of this study was to identify at the species level a large collection of Gram-negative dairy bacteria isolated from milks or semi-hard and soft, smear-ripened cheeses (cheese core or surface samples) from different regions of France. The isolates were then assessed for two risk factors, antibiotic resistance and volatile and non-volatile biogenic amine production in vitro. In total, 173 Gram-negative isolates were identified by rrs and/or rpoB gene sequencing. A large biodiversity was observed with nearly half of all Gram-negative isolates belonging to the Enterobacteriaceae family. Overall, 26 different genera represented by 68 species including potential new species were identified among the studied Gram-negative isolates for both surface and milk or cheese core samples. The most frequently isolated genera corresponded to Pseudomonas, Proteus, Psychrobacter, Halomonas and Serratia and represented almost 54% of the dairy collection. After Pseudomonas, Chryseobacterium, Enterobacter and Stenotrophomonas were the most frequently isolated genera found in cheese core and milk samples while Proteus, Psychrobacter, Halomonas and Serratia were the most frequently isolated genera among surface samples. Antibiotic resistance profiles indicated that resistances to the aminosid, imipemen and quinolon were relatively low while more than half of all tested isolates were resistant to antibiotics belonging to the monobactam, cephem, fosfomycin, colistin, phenicol, sulfamid and some from the penam families. Thirty-six% of isolates were negative for in vitro biogenic amine production. Among biogenic amine-producers, cadaverine was the most frequently produced followed by isoamylamine, histamine and putrescine. Only low levels (<75 mg/l) of tyramine were detected in vitro. © 2011 Elsevier Ltd. Source
Wilson A.E.,University of Strasbourg |
Bergaentzle M.,University of Strasbourg |
Bindler F.,University of Strasbourg |
Marchioni E.,University of Strasbourg |
And 2 more authors.
Food Control | Year: 2013
The antimicrobial activities of ten isothiocyanates (ITCs), namely sulforaphane, iberin, allyl-, benzyl-, methyl-, phenyl-, phenylethyl-, propyl-, 3-methylthiophenyl-, and 3-methylthiopropyl-ITC, were tested against a range of pathogenic and food spoilage bacteria. The activities of six ITCs were investigated for the first time. The growth of the bacteria was monitored by turbidimetry in a culture broth with increasing concentrations of ITCs. An antimicrobial efficacy index (I AE) was calculated based on the observed growth delay, reduction in maximum growth rate and reduction in population size. ITCs inhibited pathogenic and food spoilage bacteria including species from Bacillus, Escherichia, Klebsiella, Listeria, Salmonella, Serratia and Staphylococcus. Gram-negative bacteria were overall more sensitive to ITCs than their Gram-positive counterparts: the three most sensitive species with five ITCs, and two out of three most sensitive species with the other ITCs. Yet, the species of a bacterium seemed to play a more important role, since considerable variations in sensitivity were observed between species even within the same Gram type. All ITCs investigated displayed antimicrobial activity, but with levels that depended on the target bacteria and the molecule considered. The highest I AE values were obtained with Benzyl-ITC, followed by phenylethyl-ITC, but this was not necessarily the case with all aromatic ITCs. An aliphatic compound, 3-methylthiopropyl-ITC, was much more active than phenyl-ITC and 3-methylthiophenyl-ITC. Within a structural group, the activity of ITCs varied dramatically, and structural features, like the presence of a sulfinyl group, the molecule size, and the length of the hydrocarbon chain, seem to be of importance. © 2012 Elsevier Ltd. Source