Cocktail vaccine induces immunoprotection and modulates the fecal microbiota in dogs against Echinococcus granulosus infection.

Abstract

Cystic echinococcosis (CE) is a global zoonotic parasitic disease that represents a significant public health challenge. Although vaccination is considered an ideal strategy for controlling CE, no effective vaccines are currently available for dogs. Herein, bioinformatic approaches were employed to identify vaccine candidates. The selected proteins, including Echinococcus granulosus enolase (EgENO), severin (EgSev), cyclophilin (EgCyc), fatty acid-binding protein 1 (EgFABP1), calmodulin (EgCaM), and serine protease inhibitor 1 (EgSrp1), were expressed in Escherichia coli. These proteins were grouped into cocktail vaccines: rEgENO&rEgSev&rEgCyc and rEgFABP1&rEgCaM&rEgSrp1, and were combined with the Quil-A adjuvant to evaluate vaccine efficacy in beagles. After two subcutaneous immunizations, the rEgENO&rEgSev&rEgCyc and rEgFABP1&rEgCaM&rEgSrp1 vaccines reduced the parasite burden by 80.58% (p < 0.01) and 47.92% (p < 0.01), respectively. Additionally, Ligilactobacillus, Fusobacterium, and Streptococcus correlated significantly with immunoprotection. This study demonstrated bioinformatically screened antigens were effective vaccine candidates, and vaccine-microbiota interactions provided a potential strategy to improve vaccine efficacy.