Poster. From 13.5 kg live weight, 36 female pigs (LWxLD x LWxPiétrain) were assigned to control diets or to experimental diets containing cadmium‐contaminated wheat and sunflower meal without phytase (PHOS), or with 1000 FTU/kg phytase (PHYT), or with 1000/kg FTU phytase, 1000 then 700 mg/kg vitamin C and low copper content (44 then 17 mg/kg) (CuVitC). Experimental diets had Cd concentrations ranging from 0.54 to 0.72 mg/kg and were given ad libitum for the phase 2 period (27 days of exposure) or the phase 2 and growing periods (69 days) before returning to the control diets, or for the whole fattening period (132 days). All pigs were slaughtered on the same day at an average body weight of 113.1 kg. Cadmium content in the kidney was significantly increased by the contaminated diets (P < 0.001) and by the duration of exposure (P < 0.001). However, a significant variability was found as the kidney cadmium levels varied on average by a factor of two between individuals given the same treatment. Kidney cadmium concentration was slightly but not significantly lower in PHOS pigs than in PHYT pigs (P = 0.14). Pigs fed the CuVitC diets had lower cadmium level in kidney in comparison to the pigs fed the PHYT diets after 69 days (P < 0.05) or 132 days of exposure (P < 0.05). Management of calcium, phosphorus and phytase levels, reduction in copper content and supplementation with vitamin C could limit cadmium accumulation in the kidneys of exposed pigs.

According to EU regulations, slanghterhouses and cutting plants "must have facilities for disinfecting tools with hot water supplied at not less than 82°C, or an alternative system having an equivalent effect" . The aim of the present study was to identify and assess the effectiveness of alternative systems in controlled and field conditions. Several combinations of time and temperature (from 60 to 75°C and 10 to 60 s), and system s (immersion and sprayed water), were assessed on knives contaminated by bovine and porcine faeces and meat. The mean log reductions achieved in standardised conditions with naturally enriched faeces (Enterobacteriaceae) and meat (Aerobic colony count) were calculated for the alternative systems. The results for immersion at 75°C/15 s and 70°C/30s, or water spraying at 75°C/ 10s, 70°C/20 s, and 65°C/60s, were not statistically different from the reductions (3,3 to 4,3 log) obtained for the reference method of 82°C with a fixed exposure lime of l0s, and should be thus considered as relevant alternative methods.

Hepatitis E virus (HEV) infection of zoonotic origin is an emerging concern in industrialized countries. In the past few years, several cases of zoonotic hepatitis E have been identified and the consumption of food products derived from pork liver have been associated with clusters of human cases. More specifically, raw or undercooked pork products have been incriminated. Few data on the effect of heating on HEV inactivation in food products are available. In the present study, the various times and temperatures that are used during industrial processing of pork products were applied to experimentally contaminated food preparations.
After treatment, the presence of residual infectious virus particles was investigated using real-time reverse transcription- PCR and an in vivo experimental model in pigs. Results show that heating the food to an internal temperature of 71°C for 20 min is necessary to completely inactivate HEV. These results are very important for determining processing methods to ensure food safety in regard to food-borne hepatitis E.

Kidney and liver are the critical animal organs affected by dietary exposure to Cadmium (Cd). A total of 36 female pigs (LWxLD x LWxPietrain) were used to evaluate tissue accumulation following low dietary contamination during the weaning and growing period or the whole fattening period. After weaning, pigs were blocked (mean initial weight 9.2 kg) and housed in plastic and stainless steel pens until slaughtering. Following a standard phase 1 diet, three groups (n=12) received ad libitum : (1) non contamined phase 2, growing and finishing diets (control) ; (2) contamined feeds for phase 2 and growing periods before being returned to control finishing diets (control), (2) contamined feed for phase 2 and growing periods before being returned to control finishing feed ; (3) contaminated diets for all periods. In groups 2 and 3, Cd was added as Cd (NO3)2 or by introducing contamined wheat and sunflower meal in feed (final dietary concentrations 0.30 to 0.54 µg cd/kg). The average total Cd intakes of groups 1, 2 and 3 were 14 ± 7, 58 ± 12 and 102 ± 26 µg per pig respectively. Cd levels were significantly higher in liver and kidney of exposed pigs. Cd concentrations of groups 1,2 and 3 were 66 ± 47 245 ± 56, 359 ± 70 µg per kg in liver and 182 ± 86, 896 ± 375 and 1,119 ± 376 µg/kg in kidney, respectively. For all muscle samples, concentrations were below the detection limits (1 to 5 µg/kg) liver and relationships are compared with equations from literature.

Poster. A retrospective study was made to assess the risk of listeriosis following a contamination by Listeria monocytogenes of cheeses made from goat raw milk reported by the Belgian Federal Agency for the Safety of the Food Chain in 2005. On basis of the collected data, a quantitative risk assessment model was developed covering the production chain from the milking of goats until the consumed products

Poster.

The objective of this study is to evaluate the possibility of a 4 day shelf-life extension for pork meat, stored at refrigeration temperatures, when stored under modified atmosphere packaging (MAP). Three batches of fresh pork meat packed under air or MAP (70% O2 – 30% C02) were studied. The evolutions of the pH, the water activity and the gas composition of the batches during storage were monitored and the evolutions of the spoilage microflora (lactic acid bacteria, enterobacteriacae and Pseudomonas) were also evaluated. The collected data were fitted using predictive microbiology models to estimate the growth parameters of the spoilage microflora using the software Sym’Previus (http://www.symprevius.net). Simulations were then performed to evaluate the evolution of Pseudomonas in pork meat stored under the two packaging atmospheres for several realistic time temperature scenarios, reflecting poor storage profiles with temperature abuses. At the end of all the evaluated storage scenarios, microbial concentrations obtained under MAP packaging (shelf life of 11 days) were systematically lower than those obtained under air (shelf life of 7 days) and reflected satisfactory microbiological quality according to the thresholds recommended in the GHP thus proving that a 4 days extend in fresh pork meat shelf life was possible when packed under the studied modified atmosphere (70% O2 and 30% CO2).

This running review reports statistics on human cases of zoonotic disease, on the rates of infectious agents isolated from different foodstuffs unconnected with human cases, and on foodborne disease outbreaks. Salmonella enteritidis is the major serotype, and eggs and egg products still top the list in terms of cause of zoonotic diseases in humans. Food safety and hygiene control programmes deployed across the poultry industry are now paying off, leading to a drop in total human cases recorded.
Consequently, the new trend is towards an increase in the relative proportion of cases caused by Salmonella typhimurium and by meat-including pork.

Pig is considered to be the main animal reservoir of human pathogenic Yersinia enterocolitica strains.
The bacterium can be isolated from its tongue, tonsils, but can also be found in feces and on carcasses.
In France, while the main pathogenic biotypes are known for humans (4/O:3, 2/O:9 and 3/O:5,27), few prevalence data are available in the pork chain production and mainly focus on tonsils contamination.
The aim of this study was to obtain prevalence data for Y. enterocolitica on tonsils, feces and carcasses. In 2009, a prevalence study was initiated in one slaughterhouse located in Brittany (France).
Tonsils, feces and carcasses contamination of 279 pigs were followed-up during an 18 months period ranging from June 2009 to December 2010. Three sampling campaigns were lead. Hundred twenty one tonsils and 120 feces (121 randomly selected pigs) were analyzed during the first campaign (June-July 2009). Hundred fourteen feces, tonsils and carcasses (23 batches of 5 pigs) were analyzed during the 2nd campaign (October 2009-March 2010) and 44 feces, tonsils and carcasses (9 batches of 5 pigs) for the last campaign (November-December 2010).
Results showed a high variability in the pig Yersinia enterocolitica contamination (either positive tonsils or feces): 0%, 12.3% [7.5 to 19.61%] and 13.6% [6.5 to 26.8%] in campaigns 1, 2 and 3 respectively, confirming the reported seasonality of the carriage of Y. enterocolitica by pigs. The inter batches prevalence was of 34.8% [18.8 to 55.3%] in campaign 2 and of 55.5% [26.2 to 81.3%] in campaign 3.
On the 20 positive pigs found, 8 (40%) and 15 (75%) were respectively positive only on tonsils or feces, and 3 pigs only (15%) were positive both in tonsils and feces. Despite this unexpected high detection rate on feces, no carcass was found to be positive for Y.enterocolitica (swabbing of 500 cm²; campaigns 2 and 3). In this study, 82%, 7% and 11% of isolated strains belonged to biotypes 4/O:3,2/O:9 or 3/O:5,27 and 1A respectively.
In conclusion, with 12.6% [8.3 to 18.7%] of positive pigs in the cold period and 89% of pathogenic strains, this study confirms the importance of Y. enterocolitica hazard and its seasonality. At slaughter level, classical tonsils detection of Y. enterocolitica should be completed by feces and carcass sampling due to potential cross-contamination.

A stochastic modelling approach was developed to describe the distribution of Listeria monocytogenes contamination in foods throughout their shelf life. This model was designed to include the main sources of variability leading to a scattering of natural contaminations observed in food portions: the variability of the initial contamination, the variability of the biological parameters such as cardinal values and growth parameters, the variability of individual cell behaviours, the variability of pH and water activity of food as well as portion size, and the variability of storage temperatures. Simulated distributions of contamination were compared to observed distributions obtained on 5 day and 11 day-old cheese curd surfaces artificially contaminated with between 10 and 80 stressed cells and stored at 14 °C, to a distribution observed in cold smoked salmon artificially contaminated with approximately 13 stressed cells and stored at 8 °C, and to contaminations observed in naturally contaminated batches of smoked salmon processed by 10 manufacturers and stored for 10 days a 4 °C and then for 20 days at 8 °C. The variability of simulated contaminations was close to that observed for artificially and naturally contaminated foods leading to simulated statistical distributions properly describing the observed distributions. This model seems relevant to take into consideration the natural variability of processes governing the microbial behaviour in foods and is an effective approach to assess, for instance, the probability to exceed a critical threshold during the storage of foods like the limit of 100 CFU/g in the case of L. monocytogenes.

To assess the impact of the manufacturing process on the fate of Listeria monocytogenes, we built a generic probabilistic model intended to simulate the successive steps in the process. Contamination evolution was modeled in the appropriate units (breasts, dice, and then packaging units through the successive steps in the process). To calibrate the model, parameter values were estimated from industrial data, from the literature, and based on expert opinion. By means of simulations, the model was explored using a baseline calibration and alternative scenarios, in order to assess the impact of changes in the process and of accidental events. The results are reported as contamination distributions and as the probability that the product will be acceptable with regards to the European regulatory safety criterion. Our results are consistent with data provided by industrial partners and highlight that tumbling is a key step for the distribution of the contamination at the end of the process. Process chain models could provide an important added value for risk assessment models that basically consider only the outputs of the process in their risk mitigation strategies. Moreover, a model calibrated to correspond to a specific plant could be used to optimize surveillance.

The aim of the present abstract is to present a French network dedicated to the improvement of scientific knowledge about the use of protective cultures for food preservation.

Poster. IFIP, the French Pork Institute, has since 2006 been developing a database of epidemiological information, serotyping data and PFGE profiles of 550 representative Salmonella strains specifically isolated from the pig and pork industry. This database aims to establish how Salmonella strains circulate from pig farming to finished products in order to better control the hazard, and to develop a monitoring tool for the pork sector.
Moreover, since 1997, through the “Salmonella network”, AFSSA-LERQAP has been developing a national database for strains isolated from the entire agro-food chain. This database includes the most frequently detected Salmonella serotypes and contains 3500 PFGE profiles of strains isolated from food, animals and the environment. This database is regularly consulted by public health and food authorities during investigations and outbreaks. In order to improve the national surveillance of Salmonella in pig production, both institutes, IFIP and AFSSA-LERQAP, plan to share their PFGE databases. This may allow the identification of common clusters and improve the ability to react in case of outbreaks. In the present work, we report on trends in serovar and intra-serovar diversity of 550 Salmonella strains constituting the current pig and pork sector database, and make a preliminary comparison of 216 Salmonella strains from this database with the AFSSA-LERQAP database.

The European Commission has asked the European Food Safety Authority (EFSA) to produce a Quantitative Microbial Risk Assessment (QMRA) on Salmonella in porkers and breeding stock throughout the pig meat food chain, from farm to fork. The EFSA recently published this scientific advisory assessing the public health risks tied to Salmonella in pork meat and the impact of potential control measures. This document looks set to guide European Union policy in finalizing EU-wide regulations governing Salmonella control in the pork industry. Here, we keynote the main conclusions of this report, employing the same format used, i.e. answers to the questions raised by the EFSA. An estimated 10% to 20% of human Salmonella infections across the EU may be attributable to the pig reservoir as a whole, and an 80% to 90% reduction in lymph node prevalence should result in a comparable reduction in the number of human cases attributable to pig meat products. The main control measures proposed are: reduction of Salmonella prevalence in breeder pigs; control of Salmonella contamination in food; control of on-farm environmental contamination by stepping up biosecurity programmes. Furthermore, the carcass decontamination process currently used in slaughterhouses in certain EU countries is one of the prevention measures cited as a plus.

Processed meat intake is associated with colorectal cancer risk, but no experimental study supports the epidemiologic evidence. To study the effect of meat processing on carcinogenesis promotion, we first did a 14-day study with 16 models of cured meat. Studied factors, in a 2 × 2 × 2 × 2 design, were muscle color (a proxy for heme level), processing temperature, added nitrite, and packaging. Fischer 344 rats were fed these 16 diets, and we evaluated fecal and urinary fat oxidation and cytotoxicity, three biomarkers of heme-induced carcinogenesis promotion. A principal component analysis allowed for selection of four cured meats for inclusion into a promotion study. These selected diets were given for 100 days to rats pretreated with 1,2-dimethylhydrazine. Colons were scored for preneoplastic lesions: aberrant crypt foci (ACF) and mucin-depleted foci (MDF). Cured meat diets significantly increased the number of ACF/colon compared with a no-meat control diet (P = 0.002). Only the cooked nitrite-treated and oxidized high-heme meat significantly increased the fecal level of apparent total N-nitroso compounds (ATNC) and the number of MDF per colon compared with the no-meat control diet (P < 0.05). This nitrite-treated and oxidized cured meat specifically increased the MDF number compared with similar nonnitrite-treated meat (P = 0.03) and with similar nonoxidized meat (P = 0.004). Thus, a model cured meat, similar to ham stored aerobically, increased the number of preneoplastic lesions, which suggests colon carcinogenesis promotion. Nitrite treatment and oxidation increased this promoting effect, which was linked with increased fecal ATNC level. This study could lead to process modifications to make nonpromoting processed meat.

This paper keynotes the European Community zoonoses and zoonotic infectious agents report, giving special emphasis to the salmonella infections section.
Although Salmonella Enteritidis and eggs and egg products still top the list in terms of cause of zoonosis cases in humans, they are on the decline. The result is that alongside a net decrease in the total number of human cases recorded, there is an increase in the relative share of cases caused by S. typhimurium and by meat products, including pork.

Poster.

This study proposes a novel approach to assessing the impact of packaging on the microbiological spoilage of pork ribs in industrial consumer sales units.
The comparison and monitoring of two packaging modes (film and controlled atmosphere) allowed the behaviour of spoilage flora to be characterised and the results to be extrapolated, using the Sym’Previus software, to thermal scenarios other than that tested experimentally.

Direct evaluation of growth of artificially inoculated bacterial pathogens in foods using challenge-tests is an interesting tool for the management of food safety.
However, an issue is their an issue is their ability to describe the growth of a foodborne pathogen in conditions as similar as possible to a naturally contamined and routinely produced food.
In this collaborative research, the objective was to quantify the impact of several factors linked to the type of foodstuff, to biological parameters and to experimental conditions as well as to the laboratory performing the test.

To assess the impact of the manufacturing process on the fate of Listeria monocytogenes, we built a generic probabilistic model intended to simulate the successive steps in the process. Contamination evolution was modeled in the appropriate units (breasts, dice, and then packaging units through the successive steps in the process). To calibrate the model, parameter values were estimated from industrial data, from the literature, and based on expert opinion. By means of simulations, the model was explored using a baseline calibration and alternative scenarios, in order to assess the impact of changes in the process and of accidental events. The results are reported as contamination distributions and as the probability that the product will be acceptable with regards to the European regulatory safety criterion. Our results are consistent with data provided by industrial partners and highlight that tumbling is a key step for the distribution of the contamination at the end of the process. Process chain models could provide an important added value for risk assessment models that basically consider only the outputs of the process in their risk mitigation strategies. Moreover, a model calibrated to correspond to a specific plant could be used to optimize surveillance.

The aim of the study was to compare the efficiency of destructive (excision) and non-destructive (swabbing and sponging) sampling methods to enumerate aerobic mesophilic microorganisms, Enterobacteriaceae and to detect Salmonella on the surface of pork carcasses.
In three slaughterhouses, a total of 720 half-carcasses were sampled before and after chilling. On each half-carcass, four sites were sampled by both destructive and non-destructive techniques, for a respective total surface of 25 and 400 cm2.
The dispersion of lognormal distributions describing aerobic colony and Enterobacteriaceae counts were not significantly affected by the type of sampling method or by chilling. On the contrary, the mean of bacterial counts was significantly affected by the sampling technique with a better recovery for the destructive method, showing contaminations approximately 1-2 log cfu/cm2 higher than those obtained with the non-destructive techniques. The same influence was also observed for the detection of Salmonella with concentrations decreased by 0.9 and 1.2 log MPN/cm2 by sponging and swabbing compared to excision.
A significant impact of chilling was observed in two slaughterhouses with bacterial contaminations approximately 1 log cfu/cm2 lower after chilling, but not for the detection of Salmonella. For the nondestructive techniques, the efficiency of sponging to recover microorganisms was higher than swabbing.
Complementary tests performed on 120 refrigerated pork meat cuts, with 2 different types of swabs and sponges, confirmed the better recovery with excision followed by sponging and then swabbing (respectively -0.3 and -0.6 log cfu/cm2). The recovery differences between the 2 types of swab and sponges tested were about 0.1 log cfu/cm2. No impact of the surface sampled by excision of 5, 25 and 100 cm2 was observed a complementary study for aerobic mesophilic microorganisms, Enterobacteriaceae, but a negative effect of increasing surface was observed for the detection of Salmonella.
These results reinforce the significance of the sampling technique and stage when monitoring process hygiene criteria.

The current models developed in predictive microbiology to describe interactions between microflora in foods are reviewed, with a special focus on the Jameson-effect and Lotka- Volterra approaches. One case-study is further explored: modelling the sparse growth of Listeria monocytogenes in diced bacon along the shelf-life.

The assessment of the evolution of microorganisms 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 foods. The residual variability corresponded to a coefficient of variation (CV) of approximately 20% for the growth rate (μmax) and 120% for the parameter K (=μmax.lag time).
The between batches and between manufacturers variability was very dependent on the food tested and the CV of μmax ranged from 0 to 80%. The initial physiological state variability led to a CV of 110% for the factor K. It appeared that repeating a limited number of challenge tests in different batches/manufacturers for different initial physiological states is often sufficient to assess the variability of the behavior of L. monocytogenes in a given food.