Journal of Integrative Agriculture ›› 2018, Vol. 17 ›› Issue (01): 197-209.DOI: 10.1016/S2095-3119(17)61696-4

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  • 收稿日期:2017-04-18 出版日期:2018-01-20 发布日期:2018-01-04

Construction of Salmonella Pullorum ghost by co-expression of lysis gene E and the antimicrobial peptide SMAP29 and evaluation of its immune efficacy in specific-pathogen-free chicks

TIAN Qiu-feng1, 2*, ZHOU Wei1, 2*, SI Wei1, YI Fei1, 2, HUA Xin1, YUE Min3, CHEN Li-ping1, LIU Si-guo1, YU Shen-ye1   

  1. 1 Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, P.R.China
    2 Heilongjiang Bayi Agricultural University, Daqing 163319, P.R.China
    3 College of Animal Sciences, Zhejiang University, Hangzhou 310058, P.R.China
  • Received:2017-04-18 Online:2018-01-20 Published:2018-01-04
  • Contact: Correspondence YU Shen-ye, Tel: +86-451-51051733, Fax: +86-451-82733132, E-mail: yushenye@caas.cn; LIU Si-guo, Tel: +86-451-51051737, Fax: +86-451-82733132, E-mail: siguo_liu@hvri.ac.cn
  • About author:TIAN Qiu-feng, E-mail: 316308930@qq.com
  • Supported by:

    This work was supported by grants from the National Key Research and Development Program of China (2016YFD0501608), the National Natural Science Foundation of China (31470893), the Special Fund for Agro-scientific Research in the Public Interest, China (201403054) and the National High Technology Research and Development Program of China (2011AA10A210).

Abstract: In this study, a safety enhanced Salmonella Pullorum (S. Pullorum) ghost was constructed using an antimicrobial peptide gene, and evaluated for its potential as a Pullorum disease (PD) vaccine candidate.  The antimicrobial peptide SMAP29 was co-expressed with lysis gene E to generate S. Pullorum ghosts.  No viable bacteria were detectable either in the fermentation culture after induction of gene E- and SMAP29-mediated lysis for 24 h or in the lyophilized ghost products.  Specific-pathogen-free (SPF) chicks were intraperitoneally immunized with ghosts at day 7 of age and no mortality, clinical symptoms or signs of PD such as anorexia, depression and diarrhea were observed.  On challenge with a virulent S. Pullorum strain at 4 wk post-immunization, a comparatively higher level of protection was observed in the S. Pullorum ghost immunized chickens with a minimum of pathological lesions and bacterial loads compared to the birds in inactivated vaccine groups.  In addition, immunization with the S. Pullorum ghosts induced a potent systemic IgG response and was associated with significantly increased levels of cytokine IFN-γ and IL-4 and relative percentages of CD4+ and CD8+ T lymphocytes.  Our results indicate that SMAP29 can be employed as a new secondary lethal protein to enhance the safety of bacterial ghosts, and to prepare a non-living bacterial vaccine candidate that can prevent PD in chickens.

Key words: Salmonella Pullorum ,  bacterial ghost ,  antimicrobial peptide ,  immune response ,  immune protection