Efficacy of vaccination for Mycobacterium avium with whole cell and subunit vaccines in experimentally infected swine.
Mycobacterium avium infections are a common problem in large swine producing states and cause substantial financial losses at slaughter inspection due to carcass condemnation. Once the infection is established in a swine herd it is difficult to effectively prevent or eliminate the disease. Previous mouse studies in our laboratory suggested that Macrophage Inhibitory Factor-A3 (MIF-A3) is a virulence factor of M. avium and potential antigen for vaccine development. In this study we evaluated the efficacy of a killed 'whole cell' M. avium serovar 2 bacterin and conjugated MIF-A3 subunit vaccine in preventing infection and disease in swine challenged with virulent M. avium serovar 2. Gross and microscopic pathology, acid-fast staining, culture and polymerase chain reaction (PCR) for the M. avium specific insertion sequence IS902 were utilized in evaluation. Results indicated that neither vaccine prevented infection in challenged animals; however, a 47% reduction in severity of disease was found in swine vaccinated with the 'whole cell' M. avium serovar 2 bacterin. Reduction in severity of disease was not detected in animals vaccinated with the subunit MIF-A3 vaccine.
Hines
M E
ME
Veterinary Diagnostic and Investigational Laboratory, College of Veterinary Medicine, University of Georgia, Tifton 31793, USA. mhines@tifton.cpes.peachnet.edu
Frazier
K S
KS
Baldwin
C A
CA
Cole
J R
JR
Sangster
L T
LT
D000818:Animals; D001500:BCG Vaccine; D001428:Bacterial Vaccines / Q000009:adverse effects; D017931:DNA Primers; D006099:Granuloma / Q000209:etiology / Q000473:pathology / Q000662:veterinary; D008263:Macrophage Migration-Inhibitory Factors / Q000276:immunology; D051379:Mice; D009162:Mycobacterium avium / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity; D016133:Polymerase Chain Reaction; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000517:prevention & control; D014376:Tuberculosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*
D001500:BCG Vaccine; D001428:Bacterial Vaccines; D017931:DNA Primers; D008263:Macrophage Migration-Inhibitory Factors