Effectiveness of a cytolysin-enriched vaccine for protection of cattle against infectious bovine keratoconjunctivitis.
OBJECTIVE
To determine the immunogenicity of a Moraxella bovis cytolysin-enriched vaccine for prevention of infectious bovine keratoconjunctivitis (IBK).


METHODS
104 mixed-breed beef calves ranging between 4 and 8 months of age.


METHODS
Vaccines were prepared by the diafiltration of broth culture supernatant from hemolytic M bovis or sterile media. The diafiltered retentate was combined with Quil A adjuvant. Calves were randomly assigned to receive either the cytolysin vaccine (n = 35) or, as controls, adjuvant (35) or saline (0.9% NaCl) solution (34). Eyes of all calves were examined weekly for signs of IBK for 15 weeks. Calves that developed severe IBK were treated SC with florfenicol.


RESULTS
Cytolysin vaccine contained 4 proteins with molecular masses ranging between 65 and 90 kd. Cytolysin-vaccinated calves had fewer instances of IBK than control calves. The time of onset of corneal lesions in cytolysin-vaccinated calves that developed IBK was delayed, compared with that of calves in either control group. The cytolysin-Quil A vaccine contained endotoxin, but calves did not have clinical signs of illness after vaccination.


CONCLUSIONS
Calves that were vaccinated with a cytolysin-enriched vaccine had some resistance to IBK. Vaccines containing concentrated diafiltered M bovis cytolysin could protect beef calves against IBK.
George
Lisle W
LW
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Borrowman
Andrew J
AJ
Angelos
John A
JA
D000276:Adjuvants, Immunologic; D000818:Animals; D001426:Bacterial Proteins / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D007639:Keratoconjunctivitis, Infectious / Q000517:prevention & control*; D008562:Membrane Glycoproteins / Q000276:immunology*; D016955:Moraxella bovis / Q000276:immunology*; D045828:Moraxellaceae Infections / Q000517:prevention & control / Q000662:veterinary*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D062605:Quillaja Saponins; D012503:Saponins; D014462:Ultrafiltration
D000276:Adjuvants, Immunologic; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D062605:Quillaja Saponins; D012503:Saponins; D054353:Perforin; C046386:Quil A