Listeria monocytogenes contamination in French breeding and fattening turkey flocks.

This study aimed to collect data and create a database related to Listeria monocytogenes contamination in breeding and fattening turkey flocks. Seventy-five breeding turkey flocks and 86 fattening turkey flocks were sampled. Three hundred seventy-five and 428 samples were analyzed in breeding and fattening turkey flocks, respectively. L. monocytogenes was detected in 9 of 75 breeding flocks, leading to an estimated prevalence of 12% (95% confidence interval, 4.6-19.4). In fattening turkeys, the prevalence of L. monocytogenes-positive flocks was 9.3% (95% confidence interval, 3.1-15.5). The serotyping of L. monocytogenes strains highlighted the dominance of serovar 1/2a in breeding as well as in fattening turkeys. The relationship between rearing practices and L. monocytogenes status in turkey flocks was studied by using multiple correspondence analyses and then a hierarchical classification. Results were separated into two classes and revealed profiles that were associated with the presence or the absence of L. monocytogenes. This study highlighted the need to implement strict sanitary measures to reduce the risk of L. monocytogenes contamination in turkey production.

Campylobacter contamination of broiler caeca and carcasses at the slaughterhouse and correlation with Salmonella contamination.

In order to estimate the prevalence of Campylobacter spp. and Salmonella spp. on broiler chicken carcasses and the prevalence of Campylobacter spp. in caeca, 58 French slaughterhouses were investigated in 2008. Enumeration of Campylobacter spp. was also performed in order to study the relation between caeca and carcass contamination. A pool of 10 caeca and one carcass were collected from 425 different batches over a 12-month period in 2008. Salmonella was isolated on 32 carcasses leading to a prevalence of 7.5% ([5.0-10.0](95%CI)). The prevalence of Campylobacter was 77.2% ([73.2-81.2](95%CI)) in caeca and 87.5% ([84.4-90.7](95%CI)) on carcasses. No significant correlation was found between Campylobacter and Salmonella. Positive values of Campylobacter were normally distributed and the average level was 8.05 log(10) cfu/g ([7.94-8.16](95%CI)) in caeca and 2.39 cfu/g ([2.30-2.48](95%CI)) on carcasses. A positive correlation (r = 0.59) was found between the mean of Campylobacter in caeca and on carcasses (p < 0.001). Thus, carcasses from batches with Campylobacter-positive caeca had significantly (p < 0.001) higher numbers of Campylobacter per gram than batches with negative caeca. These results show that Campylobacter can be present in both matrices and reduction in caeca could be a possible way to reduce the amount of bacteria on carcasses. Of the 2504 identifications performed, 3 species of Campylobacter (Campylobacter jejuni, Campylobacter coli and Campylobacter lari) were identified. The main species recovered were C. jejuni and C. coli, which were isolated in 55.3% and 44.5% of positive samples, respectively. These two species were equally represented in caeca but C. jejuni was the most frequently isolated on carcasses with 57.1% and 42.5% of positive carcasses for C. jejuni and C. coli, respectively. This study underlines that target a reduction of Campylobacter on final products requires a decrease of contamination in caeca.

Risk factors for Listeria monocytogenes contamination in French laying hens and broiler flocks.

The objective of this study was to identify potential risk factors for Listeria monocytogenes contamination in French poultry production. Eighty-four flocks of layer hens kept in cages and 142 broiler flocks were included in this study. For each production type, a questionnaire was submitted to farmers and fecal samples were taken to assess the L. monocytogenes status of the flocks during a single visit to the farm. Two logistic regression models (specific to each production) were used to assess the association between management practices and the risk of L. monocytogenes contamination of the flock. The prevalence of L. monocytogenes-positive flocks was 30.9% (95% CI: 21.0; 40.9) and 31.7% (95% CI: 24.0; 39.4) for cage-layers and broiler flocks, respectively. For layer flocks, the risk of L. monocytogenes contamination was increased when pets were present on the production site. When droppings were evacuated by conveyor belt with deep pit storage, the risk of L. monocytogenes contamination decreased significantly. Feed meal was found to be associated with a higher risk of L. monocytogenes contamination than feed crumb. For broiler flocks, the risk of L. monocytogenes contamination was increased when farmers did not respect the principle of two areas (clean and dirty) at the poultry house entrance. A first disinfection by thermal fogging and the absence of pest control of the poultry house before the arrival of the next flock was found to increase the risk of contamination. When litter was not protected during storage and when farm staff also took care of other broiler chicken houses, the risk of L. monocytogenes contamination increased significantly. In the case of the watering system, nipples with cups were found to decrease the risk of contamination.

Prevalence of and risk factors for Campylobacter spp. contamination of broiler chicken carcasses at the slaughterhouse.

A study was conducted in 2008 to estimate the prevalence and identify the risk factors for Campylobacter spp. contamination of broiler carcasses during the slaughtering process. A pool of 10 caeca and one carcass were collected from 425 batches of broiler chickens slaughtered in 58 French slaughterhouses over a 12-month period. Potential risk factors were identified according to the Campylobacter contamination status of carcasses and processing variables identified from questionnaires. The statistical analysis took into account confounding factors that have already been associated with the presence of Campylobacter on carcasses such as the slaughter age of the chicken or seasonal variations. Campylobacter spp. were isolated from 77.2% of caeca (95% CI 73.2 to 81.2) and from 87.5% of carcasses (95% CI 84.4 to 90.7). A multiple logistic regression showed 4 parameters as significant risk factors (p < 0.05) for contamination: (I) batches were not the first to be slaughtered in the logistic schedule (OR = 3.5), (II) temperature in the evisceration room was higher than 15 °C (OR = 3.1), (III) dirty marks on carcasses after evisceration were visible (OR = 2.6) and (IV) previous thinning of the flocks, from which slaughtered batches came, had occurred at the farm (OR = 3.3). This last result highlighted the need for sanitary precautions to be taken when catching birds for transport. At the slaughterhouse, evisceration seemed to be the operation contributing most to the spread of contamination. Effective risk management solutions could include the systematic external rinsing of carcasses after evisceration and the implementation of slaughtering schedules according to the Campylobacter contamination status of flocks.

Prevalence and risk factors for Salmonella enterica subsp. enterica contamination in French breeding and fattening turkey flocks at the end of the rearing period.

An epidemiological study was conducted to estimate the prevalence of Salmonella spp. contamination in French commercial breeding and fattening turkey flocks at the end of the rearing period, as part of a European Union-wide baseline study. Two hundred and five breeding turkey flocks and three hundred and two fattening turkey flocks were included in the study, between October 2006 and September 2007. The Salmonella status of flocks was assessed by collecting five environmental faeces samples, analysed by classical bacteriological method. The prevalence of Salmonella positive flocks was 1.5% for breeding turkeys and 15.6% (95% CI: 11.5; 19.7) for fattening turkeys. Information on potential risk factors of the turkey flock being Salmonella positive was collected by questionnaire at the same time as sample collection. The association between management practices, general hygiene and Salmonella status in French turkey flocks was assessed by logistic regression. The risk of Salmonella contamination in fattening turkey flocks was decreased when floors were disinfected during decontamination procedures, when Salmonella detection was carried out during rearing and when there was a metering pump in the house. However in this study, the risk was increased when the farmer used a footbath at the turkey house entrance. Risk factors for Salmonella in breeding turkey flocks could not be subjected to formal statistical analysis since only three flocks were contaminated.

Isolation of Salmonella enterica in laying-hen flocks and assessment of eggshell contamination in France.

The present investigation was conducted in conjunction with the European Union baseline study for the estimation of Salmonella prevalence in laying-hen flocks. It aimed at evaluating eggshell contamination in farms positive for Salmonella, characterizing the genetic patterns of Salmonella strains and identifying the factors associated with Salmonella contamination of eggshells. For this purpose, a total of 4,200 eggs were collected from 28 positive flocks and analyzed according to draft Annex D of International Organization for Standardization Method 6579. Molecular characterization of the Salmonella strains was obtained by the pulsed-field gel electrophoresis method with two restriction enzymes, XbaI and BlnI. The relationship between the presence of Salmonella on eggshells and rearing practices was studied by using multiple correspondence analysis. Results showed that 39.3% of the positive flocks had at least one positive eggshell, with a total of 1.05% of eggshells testing positive for Salmonella. We detected the same serovars on samples taken from the farm and from eggshells within a given flock, with isolates sharing the same genetic pattern in 7 of 11 flocks. Eggshells tested positive for Salmonella in flocks (i) located where delivery trucks pass near air entrances of the poultry house, (ii) with high holding capacity (>30,000 laying hens), and (iii) with more than five positive samples coming from the farm environment, as well as in cases of flocks with a maximum egg-laying rate of >96% and in cases where farmers worked in other animal production. This study provided valuable information that could be used for risk management and risk assessment studies.