Incidence, pathogenesis and control measures of Enterococcus infections in chicken embryos and neonatal broiler chickens

卵黄囊感染已成为加拿大肉鸡业的头号疾病问题。过去两年，萨斯喀彻温省的家禽孵化场出现了由肠球菌引起的卵黄囊感染，因此，雏鸡质量和肉鸡生产性能显著下降。导致肉鸡新生细菌感染的病原体来自孵化场，这导致了非常高的第一周死亡率、慢性感染、在肉鸡生长发育期增加了扑杀和在加工过程中增加了谴责。此外，肠球菌的确切传播方式、输入口岸和毒力机制尚不清楚。由于这些原因，最大限度地减少孵化传播的感染和提高肉鸡群的生产性能是至关重要的。因此，适当的流行病学监测对疾病调查是必要的，并对预防和控制措施具有重要意义。本研究旨在探讨鸡胚和雏鸡肠球菌感染发病率升高的原因，并研究含CpG基序的寡脱氧核苷酸(CpG-ODN)对肠球菌感染的免疫保护作用。我们建议通过体内途径使用CpG-ODN来控制肉鸡养殖业中肠球菌感染的出现。

Yolk sac infections have become the number one disease problem in the broiler chicken industry in Canada. The emergence of yolk sac infections due to Enterococcus species has increased over the last two years at poultry hatcheries in Saskatchewan and as a result, chick quality and broiler performance have decreased significantly. Pathogens responsible for neonatal bacterial infections of broiler chickens originate from the hatchery and this leads to a very high first week mortality, chronic infections, increased culling during grow-out period of broilers and increased condemnations at processing. Moreover, the exact mode of transmission, port of entry, and virulence mechanisms of Enterococcus is unknown. Because of these reasons, it is essential to minimize hatchery-borne infections and increase the performance of broiler flocks. Therefore, appropriate epidemiological surveillance is a necessity for disease investigation, and has implications for preventive and control measures. The objective of this study is to identify the causes associated with increased incidence of Enterococcal infections in chicken embryos and neonatal chickens and to study the immunoprotective effects of oligodeoxynucleotides containing CpG motifs (CpG-ODN) against Enterococcal infections. We are proposing to use CpG-ODN by the in ovo route to control the emergence of Enterococcal infections in the broiler chicken industry.