Li Qiuchun, Zhu Yue, Yin Kequan, Xu Lijuan, Yin Chao, Li Yang, Ren Jingwei, Yuan Yu, Jiao Xinan
Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, China.
Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China.
BMC Vet Res. 2019 Jan 3;15(1):3. doi: 10.1186/s12917-018-1753-0.
Salmonella enterica serovar Pullorum is a host-restricted serotype causing infection in poultry. The pathogen can not only cause acute infection in young chicks with high mortality and morbidity, but also persist in adult chickens without evident clinical symptoms and lead to vertical transmission. To eradicate S. Pullorum in poultry farms, it is necessary to establish an efficient method to monitor the prevalence of the pathogen in adult chickens. The protein IpaJ is a specific immunogen in S. Pullorum and is not detected in closely related serotypes, such as S. Gallinarum and S. Enteritidis.
In the present study, IpaJ was expressed as a recombinant fusion protein MBP-IpaJ in E. coli. The purified MBP-IpaJ was used as a coating antigen to develop an indirect ELISA assay, which was applied to the detection of S. Pullorum infection in chickens. The indirect ELISA assay demonstrated that antibodies produced against IpaJ were detectable in antisera of chickens infected with S. Pullorum in the second week, stably increased until the tenth week, and persisted at a high level in the following two weeks. Furthermore, the ELISA method detected four positive samples out of 200 clinical antiserum samples collected from a poultry farm, and the positive samples were confirmed to be reacted with S. Pullorum using the standard plate agglutination test.
The established indirect ELISA using the IpaJ protein is a novel method for specific detection of S. Pullorum infection, and contribute to eradication of pullorum disease in the poultry industry.
鸡白痢沙门氏菌是一种宿主特异性血清型，可在家禽中引起感染。该病原体不仅能在幼雏中引起急性感染，导致高死亡率和高发病率，还能在成年鸡中持续存在而无明显临床症状，并导致垂直传播。为了在家禽养殖场根除鸡白痢沙门氏菌，有必要建立一种有效的方法来监测成年鸡中该病原体的流行情况。蛋白IpaJ是鸡白痢沙门氏菌中的一种特异性免疫原，在密切相关的血清型如鸡伤寒沙门氏菌和肠炎沙门氏菌中未检测到。
在本研究中，IpaJ在大肠杆菌中表达为重组融合蛋白MBP-IpaJ。纯化的MBP-IpaJ用作包被抗原来开发间接ELISA检测方法，用于检测鸡的鸡白痢沙门氏菌感染。间接ELISA检测表明，在感染鸡白痢沙门氏菌的鸡血清中，针对IpaJ产生的抗体在第二周可检测到，直至第十周稳定增加，并在接下来的两周内维持在高水平。此外，ELISA方法在从一个家禽养殖场收集的200份临床血清样本中检测到4份阳性样本，使用标准平板凝集试验确认这些阳性样本与鸡白痢沙门氏菌发生反应。
所建立的使用IpaJ蛋白的间接ELISA是一种特异性检测鸡白痢沙门氏菌感染的新方法，有助于在家禽业中根除鸡白痢病。
