Broiler gut health and C. jejuni infection: impacts of harvest management

生命结束概述可持续生产安全的鸡肉是国际上的优先事项，保护禽类福利是其中的关键组成部分。目前集约化的(肉鸡)生产可能会损害禽类的健康和福利以及食品安全，而且禽类福利差与弯曲杆菌公共卫生威胁之间存在很强的联系。弯曲杆菌是欧盟细菌性腹泻的最常见原因，尽管有数百万英镑的研究资金，但据估计，2013年英国受污染的鸡肉导致约700000例人类弯曲杆菌病病例，约10万人死亡。感染的特征是剧烈的腹痛和急性(有时是血性)腹泻，每年给英国造成的损失估计为10亿英镑。弯曲杆菌污染鸡肉的形式有两种。首先，屠体表面的污染会导致厨房的交叉污染。其次，肌肉和肝脏组织中的污染可能比目前认为的更重要，通过促进烹饪过程中细菌的生存而增加健康风险。在恶劣生产环境或暴露在压力下的鸡更容易受到弯曲杆菌的影响，在这些禽类中，细菌表现出更大的肠道外传播到可食用组织，可能是由于肠道环境受到干扰。因此，肉鸡福利的改善具有改善公共卫生的巨大潜力，但迫切需要关于应激影响的信息，以便提供有针对性的干预措施，以减少肉鸡中的弯曲杆菌。在任何生产流程中，肉鸡生活中的一个严重应激事件是当禽类被从农场移出屠宰时收获。我们将这一过程定义为：食物提取、捕获、运输和通过气体或电力击晕。尽管越来越多的证据表明，这些应激源可以增加弯曲杆菌的生长速度和肠道外传播，但关于它们的相对重要性或它们可能如何选择特定类型的弯曲杆菌的数据很少。通过使用大规模的行业相关实验条件、最先进的基因组学、分子微生物学和数学模型技术来研究收获过程，我们将确定收获对肉鸡肠道健康的影响。我们将结合一项研究，确定弯曲杆菌肠道外传播到可食用组织所涉及的细菌遗传决定因素。我们将量化每个收获阶段对禽类肠道细菌种群以及生理和免疫的相对影响，并研究这些因素在控制弯曲杆菌肠道外传播方面所起的作用。这项多学科的研究计划将加强对收获过程对鸟类肠道健康和弯曲杆菌的影响的了解。量化信息和模型将被用来就收获过程的要素向业界提供直接建议，这些要素为干预措施提供了最佳机会，以减轻鸡肉中弯曲菌污染的持续挑战。

Life-End summarySustainable production of safe chicken is an international priority and preserving bird welfare is a key component of this. Current intensive (broiler) production can compromise bird health and welfare and food safety and there are strong links between poor bird welfare and the Campylobacter public health threat. Campylobacter is the most common cause of bacterial diarrhoea in the EU and despite millions of pounds of research funding it is estimated that contaminated chicken caused ~700000 human campylobacteriosis cases in the UK in 2013 with around 100 deaths. Infection is characterised by severe abdominal pain and acute (sometimes bloody) diarrhoea and costs the UK an estimated £1 billion per year. Campylobacter contamination of chicken takes two forms. First, surface contamination of carcasses leads to cross-contamination in the kitchen. Second, and perhaps of greater importance than currently thought, contamination within muscle and liver tissues, increasing the health risk by facilitating bacterial survival during cooking.Chickens in poor production environments or exposed to stress are more susceptible to Campylobacter and in such birds the bacteria show greater extra-intestinal spread to edible tissues, possibly as a consequence of disturbance to the gut environment. Therefore, improvements in broiler welfare have great potential to improve public health but there is an urgent need for information on the effect of stress to inform targeted interventions to reduce Campylobacter in broiler chickens.One acutely stressful event in the life of broilers, in any production stream, is harvest when birds are removed from the farm for slaughter. We define the process as comprising: food withdrawal, catching, transport and stunning by either gas or electricity. Although there is a growing body of evidence that these stressors can increase Campylobacter growth rates as well as extra-intestinal spread, there is a paucity of data on their relative importance or how they may select for particular types of Campylobacter. By examining the harvest processes using large scale industry-relevant experimental conditions, state-of-the-art genomics, molecular microbiology and mathematical modelling techniques, we will determine the impact of harvest on gut health in broilers. We will combine this with a study to identify bacterial genetic determinants involved in extra-intestinal spread of Campylobacter to edible tissues. We will quantify the relative impact of each stage of harvest on the gut bacterial population and the physiology and immunity of the birds, and investigate the role these play in controlling extra-intestinal spread of Campylobacter. This multidisciplinary research programme will enhance understanding of the influence of the harvest process on bird gut health and Campylobacter. The quantitative information and modelling will be used to provide direct advice to industry about the elements of the harvest processes that provide the best opportunity for interventions that will mitigate the ongoing challenge of Campylobacter contamination in chicken meat.