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

Autor: Hua Xin, Liu Si-guo, Zhou Wei, Si Wei, Chen Li-ping, Yue Min, Tian Qiu-feng, Yi Fei, YU Shen-ye
Rok vydání: 2018
Předmět:
Zdroj: Journal of Integrative Agriculture, Vol 17, Iss 1, Pp 197-209 (2018)
ISSN: 2095-3119
DOI: 10.1016/s2095-3119(17)61696-4
Popis: 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.
Databáze: OpenAIRE
Externí odkaz: