ARS | Publication request: Identification and cloning of two immunogenic C. perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO) of Clostridium perfringens

Submitted to: Research in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 10, 2012
Publication Date: June 12, 2012
Citation: Lee, K., Lillehoj, H.S., Jang, S.I., Bosch, M., Bautista, D., Bosch, M.P., Pope, C.R., Ritter, D.G., Lillehoj, E., Neumann, A., Saragusa, G. 2011. Identification and cloning of two immunogenic C. perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO) of Clostridium perfringens. Research in Veterinary Science. 91(3):e80-6. DOI: 10.1016/j.rvsc.2011.01.017.

Interpretive Summary: In the United States, clostridium-related diseases such as gangrenous dermatitis (GD) and necrotic enteritis (NE) are ranked as the most important enteric and skin-associated diseases in chicken and turkey. However, there is very little information on how host immune system respond to these pathogens. Because of these pathogens secrete toxins which cause virulence, it is important to identify immunogenic toxins which can be used in the development of recombinant vaccines. In this study, ARS scientists in collaboration with scientists at the National Veterinary Research and Quarantine Service of South Korea identified two Clostridium antigens using chicken serum from field infection. The two genes which encodes two immunogenic proteins of Clostridium perfringens were expressed, recombinant proteins were used to detect antibodies in sera from birds with clinical signs of necrotic enteritis. The results showed thatthese four CPproteins are immunogenic and are recognized by immune serum from CP-infected, but not in normal chickens. The two immunogenic Clostridium perfringens (CP) proteins, elongation factor Tu [EF-Tu] and pyruvate:ferredoxin oxidoreductase [PFO] will be important diagnostic antigens for field veterinarians and will be used as potential vaccines against necrotic enteritis.

Technical Abstract: Clostridium related poultry diseases such as necrotic enteritis (NE) and gangrenous dermatitis (GD) cause substantial economic losses on a global scale. Two antigenic C. perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO), were identified by reaction with immune sera from commercial meat-type chickens with clinical outbreak of Clostridium infections. In addition to the genes encoding EF-Tu and PFO, C. perfringens alpha-toxin and necrotic enteritis B-like (NetB) toxin were also expressed in Escherichia coli and their corresponding recombinant proteins were purified. Using the four recombinant proteins as target antigens in ELISA immunoassays, high serum antibody titers were observed not only in chickens with clinical signs of Clostridium infections, but also in apparently healthy animals from the same disease-endemic farm. By contrast, no antibodies against any of the proteins were present in the serum of a specific pathogen-free bird. In Elisa using recombinant proteins of C. perfringens, the levels of anti-bacterial protein antibodies were also higher in chickens which were experimentally induced to show NE clinical signs after co-infection with C. perfringens and Eimeria maxima compared with uninfected controls. These results show that two antigenic C. perfringens proteins, EF-Tu and PFO can be useful detection antigens for C. perfringens-afflicted infections in commercial poultry.