CPB2 and intestinal disorder: Pathologically, both CPB1 and CPB2 are thought to be important virulent factors of the necrotic enteritis in humans and animals, particularly in piglets [4, 7, 8], and a presence of cpb2-positive C.  perfringens strains in the intestine has been associated with intestinal diseases in humans [9], ruminants [10], horses [7], and piglets [11, 12].