Variable protection against experimental broiler necrotic enteritis after immunization with the C-terminal fragment of Clostridium perfringens alpha-toxin and a non-toxic NetB variant

Necrotic enteritis toxin B (NetB) is a pore-forming toxin produced by Clostridium perfringens and has been shown to play a key role in avian necrotic enteritis, a disease causing significant costs to the poultry production industry worldwide. The aim of this work was to determine whether immunization with a non-toxic variant of NetB (NetB W262A) and the C-terminal fragment of C. perfringens alpha-toxin (CPA(247–370)) would provide protection against experimental necrotic enteritis. Immunized birds with either antigen or a combination of antigens developed serum antibody levels against NetB and CPA. When CPA(247–370) and NetB W262A were used in combination as immunogens, an increased protection was observed after oral challenge by individual dosing, but not after in-feed-challenge.