title: Cattle Immunized with a Recombinant Subunit Vaccine Formulation Exhibits a Trend towards Protection against Histophilus somni Bacterial Challenge.
abstract: Histophilosis, a mucosal and septicemic infection of cattle is caused by the Gram negative pathogen Histophilus somni (H. somni). As existing vaccines against H. somni infection have shown to be of limited efficacy, we used a reverse vaccinology approach to identify new vaccine candidates. Three groups (B, C, D) of cattle were immunized with subunit vaccines and a control group (group A) was vaccinated with adjuvant alone. All four groups were challenged with H. somni. The results demonstrate that there was no significant difference in clinical signs, joint lesions, weight change or rectal temperature between any of the vaccinated groups (B,C,D) vs the control group A. However, the trend to protection was greatest for group C vaccinates. The group C vaccine was a pool of six recombinant proteins. Serum antibody responses determined using ELISA showed significantly higher titers for group C, with P values ranging from < 0.0148 to < 0.0002, than group A. Even though serum antibody titers in group B (5 out of 6 antigens) and group D were significantly higher compared to group A, they exerted less of a trend towards protection. In conclusion, the vaccine used in group C exhibits a trend towards protective immunity in cattle and would be a good candidate for further analysis to determine which proteins were responsible for the trend towards protection.
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Claudia Avis
authors: CA
authors: Madampage
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Don
authors: D
authors: Wilson
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Hugh
authors: H
authors: Townsend
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Gordon
authors: G
authors: Crockford
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Neil
authors: N
authors: Rawlyk
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Donna
authors: D
authors: Dent
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Brock
authors: B
authors: Evans
authors: Alberta Beef Health Solutions Inc, Box 307, Picture Butte, Alberta, T0K 1V0, Canada.
authors: Joyce
authors: J
authors: Van Donkersgoed
authors: Veterinary Agri-Health Services, 201-151 East Lake Blvd, Airdrie, Alberta, T4A 2G1, Canada.
authors: Craig
authors: C
authors: Dorin
authors: Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: Andrew
authors: A
authors: Potter
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001428:Bacterial Vaccines / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D004269:DNA, Bacterial / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D016680:Genome, Bacterial; D006192:Haemophilus Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D044138:Haemophilus somnus / Q000276:immunology* / Q000302:isolation & purification; D007114:Immunization; D011994:Recombinant Proteins / Q000276:immunology; D014611:Vaccination; D022223:Vaccines, Subunit / Q000276:immunology*; D014774:Virulence
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D022223:Vaccines, Subunit