title: Immunization of broiler chickens against Clostridium perfringens-induced necrotic enteritis.
abstract: Necrotic enteritis (NE) in broiler chickens is caused by Clostridium perfringens. Currently, no vaccine against NE is available and immunity to NE is not well characterized. Our previous studies showed that immunity to NE followed oral infection by virulent rather than avirulent C. perfringens strains and identified immunogenic secreted proteins apparently uniquely produced by virulent C. perfringens isolates. These proteins were alpha-toxin, glyceraldehyde-3-phosphate dehydrogenase, pyruvate:ferredoxin oxidoreductase (PFOR), fructose 1,6-biphosphate aldolase, and a hypothetical protein (HP). The current study investigated the role of each of these proteins in conferring protection to broiler chickens against oral infection challenges of different severities with virulent C. perfringens. The genes encoding these proteins were cloned and purified as histidine-tagged recombinant proteins from Escherichia coli and were used to immunize broiler chickens intramuscularly. Serum and intestinal antibody responses were assessed by enzyme-linked immunosorbent assay. All proteins significantly protected broiler chickens against a relatively mild challenge. In addition, immunization with alpha-toxin, HP, and PFOR also offered significant protection against a more severe challenge. When the birds were primed with alpha-toxoid and boosted with active toxin, birds immunized with alpha-toxin were provided with the greatest protection against a severe challenge. The serum and intestinal washings from protected birds had high antigen-specific antibody titers. Thus, we conclude that there are certain secreted proteins, in addition to alpha-toxin, that are involved in immunity to NE in broiler chickens.
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors.forename: R R
authors.initials: RR
authors.lastname: Kulkarni
authors.forename: V R
authors.initials: VR
authors.lastname: Parreira
authors.forename: S
authors.initials: S
authors.lastname: Sharif
authors.forename: J F
authors.initials: JF
authors.lastname: Prescott
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002135:Calcium-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D002645:Chickens / Q000276:immunology*; D003001:Cloning, Molecular; D003015:Clostridium Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D003016:Clostridium perfringens / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D004751:Enteritis / Q000276:immunology / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*; D005634:Fructose-Bisphosphate Aldolase / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D007421:Intestine, Small / Q000276:immunology; D008297:Male; D009336:Necrosis; D011201:Poultry Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D050743:Pyruvate Synthase / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D010738:Type C Phospholipases / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D002135:Calcium-Binding Proteins; D011994:Recombinant Proteins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D050743:Pyruvate Synthase; D010738:Type C Phospholipases; C040649:alpha toxin, Clostridium perfringens; D005634:Fructose-Bisphosphate Aldolase