Unité Hygiène et Qualité des Produits Avicoles et Porcins, Laboratoire d'Etude de Recherche Avicole et Porcine, AFSSA site de Ploufragan, BP 53, 22440 Ploufragan, France.
J Food Prot. 2009 Oct;72(10):2071-7. doi: 10.4315/0362-028x-72.10.2071.
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.
本研究与欧盟进行的沙门氏菌在蛋鸡群中流行率基线研究同时进行。其旨在评估沙门氏菌阳性农场中鸡蛋壳的污染情况，对沙门氏菌菌株的遗传模式进行特征描述，并确定与鸡蛋壳污染沙门氏菌相关的因素。为此，从 28 个阳性鸡群中总共采集了 4200 个鸡蛋，并根据国际标准化组织方法 6579 草案附件 D 进行分析。沙门氏菌菌株的分子特征通过 XbaI 和 BlnI 两种限制酶的脉冲场凝胶电泳方法获得。使用多元对应分析研究了沙门氏菌在鸡蛋壳上的存在与饲养实践之间的关系。结果表明，39.3%的阳性鸡群至少有一个鸡蛋壳呈阳性，共有 1.05%的鸡蛋壳检测出沙门氏菌阳性。我们在同一鸡群的农场样本和鸡蛋壳样本中检测到了相同的血清型，在 11 个鸡群中有 7 个鸡群的分离株具有相同的遗传模式。沙门氏菌阳性的鸡群（i）位于送货车经过鸡舍空气入口附近的地方，（ii）具有较高的存栏量（>30000 只蛋鸡），（iii）来自农场环境的阳性样本超过 5 个，以及产蛋率最高超过 96%的鸡群和从事其他动物生产的农民的鸡群。本研究提供了有价值的信息，可用于风险管理和风险评估研究。
