畜牧兽医学报 ›› 2018, Vol. 49 ›› Issue (4): 786-793.doi: 10.11843/j.issn.0366-6964.2018.04.016

• 预防兽医 • 上一篇    下一篇

胞内劳森菌LsaA蛋白的原核表达及间接ELISA抗体检测方法的建立

吴艳阳, 杨东东, 高冬生, 李永涛, 常洪涛, 王川庆, 赵军*   

  1. 河南农业大学牧医工程学院, 郑州 450002
  • 收稿日期:2017-07-10 出版日期:2018-04-23 发布日期:2018-04-19
  • 通讯作者: 赵军,E-mail:zhaoj@henau.edu.cn
  • 作者简介:吴艳阳(1993-),女,河南新乡人,硕士生,主要从事动物疫病监测与防控研究,E-mail:357671806@qq.com。
  • 基金资助:

    国家重点研发计划(2016YFD0501102;2016YFD0500802);河南省高校科技创新团队支持计划(14IRTSTHN015)

Prokaryotic Expression of LsaA Protein of Lawsonia Intracellularis and Development of a LsaA-based Indirect ELISA for Antibody Detection

WU Yan-yang, YANG Dong-dong, GAO Dong-sheng, LI Yong-tao, CHANG Hong-tao, WANG Chuan-qing, ZHAO Jun*   

  1. College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, China
  • Received:2017-07-10 Online:2018-04-23 Published:2018-04-19

摘要:

为建立胞内劳森菌特异性抗体检测方法,将密码子优化合成的胞内劳森菌表面蛋白LsaA的编码基因克隆于pET32a(+)载体,在大肠杆菌BL21(DE3)中诱导表达。用纯化的重组LsaA蛋白作为包被抗原,通过一系列条件优化,建立了检测胞内劳森菌抗体的间接ELISA方法。结果显示:该方法可以特异地检测抗胞内劳森菌抗体,与大肠杆菌、猪霍乱沙门菌、猪流行性腹泻病毒和猪传染性胃肠炎病毒等常见猪腹泻病原的抗血清均无交叉反应。来自PCR检测粪便呈胞内劳森菌阳性猪的血清,用所建立ELISA检测均为胞内劳森菌抗体阳性。该方法具有较好的敏感性和重复性,阳性血清经过1∶800稀释检测结果仍为阳性,批内和批间重复试验的变异系数分别为0.352%~2.752%和0.877%~3.000%。应用建立的ELISA方法对河南省部分地区猪场胞内劳森菌的感染情况进行了血清流行病学调查,结果显示被检地区猪场均存在不同程度的胞内劳森菌抗体阳性,阳性率在13.3%~57.1%,平均阳性率为30.6%。结果表明,本研究所建立的ELISA方法可以用于胞内劳森菌抗体的检测,为胞内劳森菌感染的监测和流行病学调查提供了方法。

关键词: 猪增生性肠炎, 胞内劳森菌, LsaA蛋白, 间接ELISA

Abstract:

In order to establish a method for detecting specific antibody against Lawsonia intracellularis, the codon-optimized LsaA gene encoding surface protein LsaA of L. intracellularis was cloned into pET32a (+) vector, and the expression of LsaA protein was induced in E. coli host BL21 (DE3). After optimization of a series of conditions, an indirect ELISA for detecting antibodies against L. intracellularis was established by using purified LsaA protein as coating antigen. The results showed that the anti- L. intracellularis antibodies were detected specifically by the established ELISA, and there were no cross-reactions with the antibodies against common diarrhea-causing pathogens such as E. coli, Salmonella choleraesuis, porcine epidemic diarrhea virus and transmissible gastroenteritis virus. Serum samples from fecal L. intracellularis-positive pigs which were identified by PCR, were also positive for anti- L. intracellularis antibodies detected by the established ELISA. The ELISA has good sensitivity and repeatability. Anti- L. intracellularis positive serum with 1:800 dilution was still ELISA positive. The intra-and inter-assay coefficient of variation was 0.352%-2.752% and 0.877%-3.000%, respectively. Seroepidemiological prevalence of L. intracellularis infection in partial pig farms in Henan province was investigated by using the established ELISA. The results indicated that all the tested pig farms were anti- L. intracellularis antibody positive with positive rate of 13.3% to 57.1%, with average positive rate of 30.6%. The results showed that the established ELISA in this study can be used for the detection of antibodies against L. intracellularis, and provides a method for the monitoring and epidemiological investigation of L. intracellularis.

Key words: porcine proliferative enteritis, Lawsonia intracellularis, LsaA protein, indirect ELISA

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