Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.
Institute of Food Safety and Food Hygiene, Freie Universität Berlin, Berlin, Germany.
BMC Microbiol. 2023 Aug 5;23(1):209. doi: 10.1186/s12866-023-02963-1.
Effective strategies are urgently needed to control Campylobacteriosis, one of the most important foodborne gastrointestinal diseases worldwide. Administering bacteriophages (phages) is under evaluation as a possible intervention strategy in primary poultry production to reduce the public health risk of human infection. A major challenge is the translation of results from small-scale animal studies to large broiler flocks. In this study, the in vitro lytic activity of 18 Campylobacter-specific group II phages and 19 group III phages were examined singly, and in different combinations from the same group and from both groups using a planktonic killing assay. Based on these results, a combination of phage NCTC 12,673 (group III) and vB_CcM-LmqsCPL1/1 (group II) was selected for in vivo application in a seeder bird model to study its effectiveness under conditions as close as possible to field conditions. One hundred eighty Ross 308 broiler chickens were divided into a control and a treatment group. Ten days post hatch, seeder birds were orally inoculated with the C. jejuni target strain. Phages were administered via drinking water at a total concentration of 10 PFU/mL four, three, and two days before necropsy.
Combining group II and group III phages resulted in significantly higher in vitro growth inhibition against the C. jejuni target strain BfR-CA-14,430 than single application or combinations of phages from the same group. The results of the animal trial showed that the application of the two phages significantly reduced Campylobacter counts in cloacal swabs. At necropsy, Campylobacter counts in colonic content of the treatment group were significantly reduced by 2 log units compared to the control group.
We demonstrated that combining phages of groups II and III results in significantly increased lytic activities. The in vitro results were successfully translated into practical application in a study design close to field conditions, providing new data to apply phages in conventional broiler flocks in the future. Phage application reduced the fecal Campylobacter excretion and Campylobacter concentrations in the colon of broilers.
有效策略迫切需要控制弯曲菌病，这是世界上最重要的食源性胃肠道疾病之一。在初级家禽生产中，施用噬菌体（噬菌体）作为一种可能的干预策略正在评估中，以降低人类感染的公共健康风险。一个主要的挑战是将小规模动物研究的结果转化为大型肉鸡群。在这项研究中，单独检查了 18 种禽源特异性 II 组噬菌体和 19 种 III 组噬菌体的体外裂解活性，以及来自同一组和两组的不同组合的体外裂解活性，使用浮游生物杀伤测定法。基于这些结果，选择噬菌体 NCTC 12,673（III 组）和 vB_CcM-LmqsCPL1/1（II 组）的组合用于在种禽模型中进行体内应用，以在尽可能接近田间条件的条件下研究其有效性。180 只罗斯 308 肉鸡被分为对照组和治疗组。孵化后 10 天，种禽经口接种鸡空肠弯曲菌目标株。噬菌体通过饮水以 10 PFU/mL 的总浓度给药，在剖检前四天、三天和两天给药。
与单独应用或同一组噬菌体组合相比，组合 II 和 III 噬菌体的组合导致对鸡空肠弯曲菌目标株 BfR-CA-14,430 的体外生长抑制显著增加。动物试验结果表明，两种噬菌体的应用显著降低了直肠拭子中的弯曲菌计数。在剖检时，与对照组相比，治疗组结肠内容物中的弯曲菌计数降低了 2 个对数单位。
我们证明了组合 II 和 III 组的噬菌体可显著提高裂解活性。体外结果成功转化为接近田间条件的研究设计中的实际应用，为未来在常规肉鸡群中应用噬菌体提供了新的数据。噬菌体的应用减少了肉鸡粪便中的弯曲菌排泄和结肠中的弯曲菌浓度。
