Vaccination with combined vaccines for eimeria maxima EF-1a and multi-component antigens from clostridium perfringens conferred effective protection against necrotic enteritis challenge in chickens

Authors: QINGZHENG, ZHANG - Nanjing Agricultural University; YUE, YUAN - (NCE, CECR)networks Of Centres Of Exellence Of Canada, Centres Of Excellence For Commercilization A; XIANGLIN, PU - Nanjing Agricultural University; LIXIN, XU - Nanjing Agricultural University; XIAOKAI, SONG - Nanjing Agricultural University; RUOFENG, YAN - Nanjing Agricultural University; XIANGRUI, LI - Nanjing Agricultural University; Li, Charles; MINGMIN, LU - Nanjing Agricultural University

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2024
Publication Date: 12/17/2024
Citation: Qingzheng, Z., Yue, Y., Xianglin, P., Lixin, X., Xiaokai, S., Ruofeng, Y., Xiangrui, L., Li, C.Z., Mingmin, L. 2024. Vaccination with combined vaccines for eimeria maxima EF-1a and multi-component antigens from clostridium perfringens conferred effective protection against necrotic enteritis challenge in chickens. Poultry Science. 104(2). Article e1043687. https://doi.org/10.1016/j.psj.2024.104687.
DOI: https://doi.org/10.1016/j.psj.2024.104687

Interpretive Summary: Necrotic enteritis (NE) is a serious condition caused by a harmful bacterium called Clostridium perfringens that mainly affects the small intestine of broiler chickens. This disease leads to about $6 billion in losses each year in the poultry industry. With stricter rules on using antibiotics in animal feed, finding alternative ways to prevent NE has become crucial. Developing effective vaccines is now a top priority for broiler chickens. One factor that makes NE worse is coccidiosis, an infection caused by parasite Eimeria species. This suggests that controlling coccidiosis could help reduce NE outbreaks. Our research focused on testing the effectiveness of vaccines made from a combination of 1 E. maxima protein and 5 specific proteins from C. perfringens. We created these protein and DNA vaccines, and studied their ability to protect chickens by measuring weight gain, disease severity, survival rates, and antibody levels. In this study, young broiler chicks received two vaccinations with these DNA or proteins, followed by the challenge with both related parasites and bacteria. The chickens vaccinated with 5 pooled antigens from bacteria or combination antigens from both parasites (1) and bacteria (5) showed much higher levels of antibodies compared to the unvaccinated ones. After being exposed to both related parasites and bacteria, the vaccinated group gained more weight, had no deaths, and showed the least amount of disease damage. Overall, the findings suggest that using combined vaccines targeting both C. perfringens and E. maxima could be a promising strategy to improve protection against NE in chickens, therefore enhancing the poultry health, welfare, and production performance.

Technical Abstract: Necrotic enteritis (NE) is a serious condition caused by a harmful bacterium called Clostridium perfringens that mainly affects the small intestine of broiler chickens. This disease leads to about $6 billion in losses each year in the poultry industry. With stricter rules on using antibiotics in animal feed, finding alternative ways to prevent and treat NE has become crucial. Developing effective vaccines is now a top priority for broiler chickens.One factor that makes NE worse is coccidiosis, an infection caused by Eimeria species. This suggests that controlling coccidiosis could help reduce NE outbreaks. Our research focused on testing the effectiveness of vaccines made from a combination of E. maxima proteins and specific proteins from C. perfringens. We created these vaccines and studied their ability to protect chickens by measuring weight gain, disease severity, survival rates, and antibody levels.Young broiler chicks received two vaccinations with these proteins on Days 7 and 17. The vaccinated chickens showed much higher levels of antibodies compared to the unvaccinated ones. After being exposed to both E. maxima and C. perfringens, the vaccinated group gained more weight, had no deaths, and showed the least amount of disease damage.Overall, our findings suggest that using combined vaccines targeting both C. perfringens and E. maxima could be a promising strategy to improve protection against NE in chickens.