Salmonella chitosan nanoparticle vaccine administration is protective against Salmonella enteritidis in broiler birds

Authors: ACEVEDO-VILLANUEVA, KEILA - University Of Georgia; Shanmugasundaram, Revathi; RNU, SANKAR - The Ohio State University; GOURAPURA, RENUKARADHIYA - The Ohio State University; AKERELE, GABRIEL - University Of Georgia; SELVARAJ, RAMESH - University Of Georgia

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2021
Publication Date: 11/16/2021
Citation: Acevedo-Villanueva, K., Shanmugasundaram, R., Rnu, S., Gourapura, R., Akerele, G., Selvaraj, R. 2021. Salmonella chitosan nanoparticle vaccine administration is protective against Salmonella enteritidis in broiler birds. PLoS ONE. 16(11):e0259334.. https://doi.org/10.1371/journal.pone.0259334.
DOI: https://doi.org/10.1371/journal.pone.0259334

Interpretive Summary: Salmonella poultry vaccines have a withdrawal period of twenty-one days before slaughter. Live vaccines require two doses, three to four weeks apart, whereas inactivated vaccines can be administered simultaneously or after live vaccines. Administrating a live vaccine followed by a killed vaccine booster can eliminate the time restrictions of live vaccine boosters and allow producers to comply with the withdrawal period. Our study aimed to evaluate the efficacy of administrating a live Salmonella vaccine followed by a killed Salmonella chitosan nanoparticle (CNP) booster vaccine on the cellular and humoral immunity of broilers. This study demonstrated that the CNP vaccination and CNP booster vaccination can 1) induce an antigen-specific immune response against Salmonella Enteritidis (S. Enteritidis), 2) can activate the intestinal mucosal immune system, 3) can decrease the S. Enteritidis loads in ceca, and 4) does not have any adverse effects on the bird’s immune status or production performance parameters. We conclude that the CNP vaccine can be administered either as a first dose or as a booster vaccination, making it an alternative vaccine candidate against Salmonella in poultry.

Technical Abstract: We evaluated the efficacy of administrating a live Salmonella vaccine followed by a killed Salmonella chitosan nanoparticle (CNP) vaccine booster on the cellular and humoral immunity of broilers. The live Salmonella vaccine used was Poulvac®ST. The CNP vaccine was synthesized with Salmonella Enteritidis (SE) outer-membrane-proteins (OMPs) and flagellin proteins. At d1-of-age, one-hundred-sixty-eight chicks were allocated into treatments: 1) No vaccine, 2) Live vaccine, 3) CNP vaccine, 4) Live+CNP vaccine. At d1, birds were orally vaccinated with PBS, Poulvac®ST, or CNP. At d7, birds were orally vaccinated with PBS or CNP. At d14, birds were orally challenged with 1×109 CFU/bird SE. There were no significant differences in BWG or FCR. The CNP and Live+CNP-vaccinated birds had significantly higher OMPs-specific mucosal IgA production and lymphocyte proliferation response. At d28, CNP and Live+CNP-vaccinated birds had 0.9 Log10 CFU/g and 1 Log10 CFU/g decreased SE cecal loads (P<0.05), respectively, compared to control. The vaccine under study does not have any adverse effects on the bird’s BWG and FCR or the IL-1ß, IL-10, IFN-', or iNOS mRNA expression levels. We concluded that the CNP vaccine, either as a first dose or as a booster vaccination, is an alternative vaccine candidate against Salmonella in poultry.