Immunization with pooled antigens for Clostridium perfringens conferred partial protection against experimental necrotic enteritis in broiler chickens

Authors: YUAN, BAOHONG - US Department Of Agriculture (USDA); SUN, ZHIFENG - US Department Of Agriculture (USDA); LU, MINGMIN - US Department Of Agriculture (USDA); Lillehoj, Hyun; LEE, YOUNGSUB - US Department Of Agriculture (USDA); LIU, LIHENG - US Department Of Agriculture (USDA); Yan, Xianghe; Li, Charles

Submitted to: Vaccines
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2022
Publication Date: 6/20/2022
Citation: Yuan, B., Sun, Z., Lu, M., Lillehoj, H.S., Lee, Y., Liu, L., Yan, X., Li, C.Z. 2022. Immunization with pooled antigens for Clostridium perfringens conferred partial protection against experimental necrotic enteritis in broiler chickens. Vaccines. 10(6):979. https://doi.org/10.3390/vaccines10060979.
DOI: https://doi.org/10.3390/vaccines10060979

Interpretive Summary: Necrotic enteritis (NE) is an economically important infectious disease caused by pathogenic Clostridium perfringens bacteria, accounting for $6 billion loss in the poultry industry worldwide. The rise of NE has been associated with the reduction or complete withdrawal of antibiotic growth promoters from animal feed during recent years. Therefore, the development of effective vaccines specific to NE is a priority for the poultry industry. By far, no effective NE vaccines are commercially available for broiler chickens. This study aimed to identify the potential of C. perfringens proteins as vaccine targets. Three different proteins were made that targeted major functions of the bacteria involved in its adhesion, localization and proliferation. The effectiveness was evaluated with a potent necrotic enteritis model. The vaccine treatments consisted of three individual protein groups and a pooled group with mixture of all three proteins. Control groups consisted of uninfected birds, sham-injected birds, and infected birds with no other vaccine but adjuvant alone. Young chicks were immunized twice subcutaneously with the constructed proteins. Following the infection challenge, the pooled protein group demonstrated no mortality, lower lesion scores and high antibody responses to key proteins. The results indicate that the immunization with multicomponent proteins may confer partial protection against virulent challenge in broiler chickens.

Technical Abstract: Necrotic enteritis (NE) is an economically important and multifactorial enteric infectious disease etiologically caused by pathogenic Clostridium perfringens infection, accounting for $6 billion loss in the global poultry industry. The increasing incidence of NE has been associated with the reduction or complete withdrawal of antibiotic growth promoters from animal feed during recent years. Therefore, the development of effective vaccines specific to NE assumes a priority for the poultry industry. By far, no effective vaccines are commercially available in broiler chickens. This study aimed to identify the potential C. perfringens proteins as vaccine targets for NE. Three recombinant C. perfringens proteins targeting five antigens were prepared: one chimeric protein consisting of two major virulence-related toxoids (alpha-toxin and NetB), and another chimeric protein consisting of two enzymes of Fructose-1,6-bisphosphate aldolase (FBA) and a Zinc metalloprotease (Zm), and one pilus subunit (Collagen adhesion protein (Cna)). Their protection efficacies were evaluated with a potent model of Eimeria maxima/C. perfringens challenge using a netB+tpeL+ C. perfringens strain. Young chicks were immunized twice subcutaneously with adjuvanted C. perfringens proteins on Days 4 and 15. Prior to the challenge, the chickens immunized with Cna, FBA and Zm antigens had much higher serum antibody titers. Following the challenge, the pooled antigens-immunized group demonstrated no mortality and least lesion scores against virulent challenge. The results indicate that the immunization with multicomponent antigens, including C. perfringens housekeeping protein Cna, may confer partial protection.