Keila Acevedo-Villanueva, Gabriel Akerele, Walid Al-Hakeem, Daniel Adams, Renukaradhy Gourapura, Ramesh Selvaraj
There is a critical need for an oral-killed vaccine for broilers. Chitosan nanoparticle (CNP) vaccines can be used to deliver antigens orally. We investigated the efficacy of a killed CNP vaccine on broilers. CNP vaccine was synthesized using enterica serovar Enteritidis (. Enteritidis) outer membrane and flagella proteins. CNP was stable at acidic conditions by releasing 14% of proteins at pH 5.5. At 17 h post-incubation, the cumulative protein release for CNP was 75% at pH 7.4. Two hundred microliters of PBS with chicken red blood cells incubated with 20 μg/ml CNP released 0% hemoglobin. Three hundred chicks were allocated into 1) Control, 2) Challenge, 3) Vaccine + Challenge. At d1 of age, chicks were spray-vaccinated with PBS or 40 mg CNP. At d7 of age, chicks were orally-vaccinated with PBS or 20 μg CNP/bird. At d14 of age, birds were orally-challenged with PBS or 1 × 10 CFU/bird of . Enteritidis. The CNP-vaccinated birds had higher antigen-specific IgY/IgA and lymphocyte-proliferation against flagellin ( < 0.05). At 14 days post-infection, CNP-vaccinated birds reversed the loss in gut permeability by 13% ( < 0.05). At 21 days post-infection, the CNP-vaccinated birds decreased . Enteritidis in the ceca and spleen by 2 Log CFU/g, and in the small intestine by 0.6 Log CFU/g ( < 0.05). We conclude that the CNP vaccine is a viable alternative to conventional poultry vaccines.
