Salmonella is an important zoonotic pathogen and is one of the main causes of foodborne outbreaks and infections in the European Union. Pigs are a significant reservoir and are frequently subclinical carriers of this organism. Salmonella can be shed in the faeces allowing infection to spread to other pigs, the environment, transport vehicles, lairages and other areas. Inadvertent spillage of gut contents during the slaughter process also leads to contamination. A pig Salmonella control programme has operated in Ireland since 2002 but many local surveys and an EUMS baseline survey in 2008 continued to indicate high levels of the organism in the pig sector. The objectives of this study were to generate updated information on the prevalence of Salmonella spp, in slaughter pigs and carcasses in Irish abattoirs. Five pigs from each of 164 herds were randomly sampled over a 14-week period during 2016. One sample from each of the five pigs of; caecal content, ileo-caecal lymph nodes and carcass swabs (pre-chill) were collected. The five caeca and lymph node samples from each herd were processed as one pool of caecal samples and one pool of lymph node samples, respectively, while the five carcass swabs were tested as individual samples. All isolates were characterised by serotyping and antimicrobial susceptibility. In total, 235 Salmonella spp. were isolated from 820 individual carcass swabs, 164 pooled lymph nodes and 164 caecal contents. Salmonella spp. were isolated from 54.3% of the caecal contents and from 31.7% of the ileo-caecal lymph node sample pools. A total of 11.5% of carcass-swab samples yielded Salmonella spp. S. Typhimurium 4,[5],12:i:1,2 or its monophasic variant 4,[5],12:i:-: predominated among isolates from all positive samples; accounting for 73% of lymph nodes, 68% of caecal contents and 56% of carcass swab isolates. S. London and S. Derby were the next most common isolated serotypes. These results confirm continuing high levels of Salmonella in fattening pigs in Ireland although reductions in carcass contamination compared to previous surveys were noted. A high prevalence of Salmonella in lymph nodes suggests that it remains a significant problem pre slaughter and a challenge to abattoirs in adhering to process hygiene requirements. The high prevalence of monophasic S. Typhimurim 4,[5],12:i:-: is of serious concern. Therefore, it is important to identify contributing factors in the dissemination of this pathogen in the pork industry in order to minimise the risk of human salmonellosis cases.

中文翻译：

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沙门氏菌的流行率。爱尔兰屠宰场的屠宰猪和屠体及其抗菌素耐药性

沙门氏菌是一种重要的人畜共患病病原体，是欧盟食源性疾病暴发和感染的主要原因之一。猪是一个重要的宿主，并且经常是这种生物的亚临床携带者。沙门氏菌可以在粪便中排出，使感染传播到其他猪、环境、运输车辆、畜栏和其他区域。屠宰过程中肠道内容物的意外溢出也会导致污染。自 2002 年以来，爱尔兰开始实施猪沙门氏菌控制计划，但许多地方调查和 2008 年的 EUMS 基线调查继续表明养猪部门的微生物水平很高。本研究的目的是生成有关爱尔兰屠宰场屠宰猪和屠体中沙门氏菌流行率的最新信息。在 2016 年的 14 周期间内，从 164 个猪群中的每一个猪群中随机抽取了 5 头猪样本。收集盲肠内容物、回盲肠淋巴结和胴体拭子（预冷）。每个畜群的五个盲肠和淋巴结样本分别作为一个盲肠样本池和一个淋巴结样本池进行处理，而五个胴体拭子作为单个样本进行测试。所有分离株的特征在于血清分型和抗菌药物敏感性。总共有 235 种沙门氏菌。从 820 个单独的胴体拭子、164 个汇集淋巴结和 164 个盲肠内容物中分离出。沙门氏菌属 从 54.3% 的盲肠内容物和 31.7% 的回盲盲肠淋巴结样本池中分离出。总共 11.5% 的尸体拭子样本产生了沙门氏菌。鼠伤寒沙门氏菌 4,[5],12:i:1, 2或其单相变体4，[5]，12：i：-：在所有阳性样本的分离物中占主导地位；占淋巴结的 73%，盲肠内容物的 68%，胴体拭子分离株的 56%。S. London 和 S. Derby 是下一个最常见的分离血清型。这些结果证实了爱尔兰育肥猪中沙门氏菌的持续高水平，尽管与之前的调查相比，胴体污染有所减少。淋巴结中沙门氏菌的高流行表明它仍然是屠宰前的一个重大问题，也是屠宰场在遵守工艺卫生要求方面的挑战。单相鼠伤寒沙门氏菌 4,[5],12:i:-: 的高流行率令人严重关切。所以，