title: Efficacy of recombinant sialoglycoprotease in protection of cattle against pneumonic challenge with Mannheimia (Pasteurella) haemolytica A1.
abstract: Secreted recombinant sialoglycoprotease fusion protein (Gcp-F) of Mannheimia (Pasteurella) haemolytica A1 was examined for its ability to protect cattle from experimental challenge with M. haemolytica A1. Five M. haemolytica vaccines were compared including Gcp-F, logarithmic phase culture supernate (Presponse) and Presponse enriched with Gcp-F, recombinant leukotoxin (rLkt) or both. All calves receiving Gcp-F had significant serum antibody responses to this antigen, measured by ELISA, prior to challenge. Those vaccinated with Gcp-F alone had significantly lower percent pneumonic tissue than unvaccinated controls and a trend (P=0.085, one-tailed test) to lower clinical scores. Calves receiving Presponse with Gcp-F and rLkt had lower percent pneumonic tissue than those receiving Presponse alone, and calves receiving Presponse enriched with Gcp-F and/or rLkt had lower mean clinical scores, but the differences were not significant. This trial demonstrates the protective capacity of sialoglycoprotease. While, remarkably, recombinant Gcp-F provided some protection alone the results support its practical potential as a component of a multiple antigen vaccine.
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, Ont., Canada N1G 2W1. pshewen@uoguleph.ca
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Shewen
authors.forename: Chiang W
authors.initials: CW
authors.lastname: Lee
authors.forename: Ann
authors.initials: A
authors.lastname: Perets
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Hodgins
authors.forename: Katherine
authors.initials: K
authors.lastname: Baldwin
authors.forename: Reggie Y C
authors.initials: RY
authors.lastname: Lo
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001428:Bacterial Vaccines / Q000138:chemical synthesis / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D016978:Mannheimia haemolytica / Q000201:enzymology / Q000276:immunology* / Q000472:pathogenicity; D008666:Metalloendopeptidases / Q000276:immunology*; D010326:Pasteurella Infections / Q000276:immunology / Q000662:veterinary*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic; D008666:Metalloendopeptidases; C070738:O-sialoglycoprotein endopeptidase