Submitted to: Avian Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/20/2013
Publication Date: 10/25/2013
Citation: Lee, K.W., Lillehoj, H.S., Park, M.S., Jang, S., Ritter, D.G., Hong, Y.H., Jeong, W., Jeoung, H.Y., An, D.J., Lillehoj, E.P. 2013. Clostridium Perfringens a-Toxin and NetB Toxin Antibodies and their possible role in protection against Necrotic Enteritis and Gangrenous Dermatitis in broiler chickens. Avian Diseases. 56(1):230-3. Interpretive Summary: Two major infections caused by Clostridium bacteria in chickens and turkeys are necrotic enteritis (NE) and gangrenous dermatitis (GD), emerging infections associated with the use of antibiotics in the field. There are no effective vaccines against NE and GD. Ability to detect these infections using serum antibodies will facilitate early diagnosis and management of these infections. In this paper, ARS scientists developed an ELISA method to detect serum antibodies which are specific for two major toxins of Clostridium perfringens, alpha-toxin and Net-B toxins. Using this ELISA, serum antibody levels to C. perfringens a-toxin and NetB toxin were measured in commercial birds from field outbreaks of NE and GD. The results showed that the levels of antibodies against both toxins were significantly increased in healthy chickens compared with birds showing clinical signs of NE or GD. This finding demonstrates the usefulness of alpha-toxin- and NetB- specific antibody detection ELISA assay for early diagnosis of clostridium infections in commercial broiler chickens. This method described in this report may advance the development of an effective management strategy against NE and GD by the poultry industry.
Technical Abstract: Necrotic enteritis (NE) and gangrenous dermatitis (GD) are important infectious diseases of poultry. Although NE and GD share a common pathogen, Clostridium perfringens, they differ in other important aspects, such as clinical signs, pathologic symptoms, and age of onset. The primary virulence factors of C. perfringens are its four major toxins and the newly described NE B-like (NetB) toxin. While neutralizing antibodies against some C. perfringens toxins are associated with protection against infection in mammals, the serological responses of NE- and GD-afflicted birds to these toxins have not been evaluated. Therefore, we measured serum antibody levels to C. perfringens alpha-toxin and NetB toxin in commercial birds from field outbreaks of NE and GD using recombinant toxin-based enzyme-linked immunosorbent assay (ELISA). Initially, we used this ELISA system to detect antibody titers against C. perfringens alpha-toxin and NetB toxin which were increased in birds experimentally co-infected with E. maxima and C. perfringens compared with uninfected controls. Next, we applied this ELISA to field serum samples from flock-mated birds with or without clinical signs of NE or GD. The results showed that the levels of antibodies against both toxins were significantly higher in apparently healthy chickens compared with birds with clinical signs of NE or GD, suggesting that these anti-toxin antibodies may play a role in protection against NE and GD. Key words: Necrotic enteritis, gangrenous dermatitis, Clostridium perfringens, broiler chicken.