Ml. Cross et al., Systemic but not intra-intestinal vaccination with BCG reduces the severity of tuberculosis infection in ferrets (Mustela furo), INT J TUBE, 4(5), 2000, pp. 473-480
Citations number
25
Categorie Soggetti
Cardiovascular & Respiratory Systems
Journal title
INTERNATIONAL JOURNAL OF TUBERCULOSIS AND LUNG DISEASE
SETTING: Ferrets are important wildlife vectors of bovine tuberculosis (Myc
obacterium bovis) in New Zealand. By reducing the severity and/or incidence
of tuberculosis (TB) in wild ferret populations, vaccination may limit dis
ease transmission to livestock.
OBJECTIVE: To investigate whether vaccination of ferrets with attenuated M.
bovis BCG via systemic or intraintestinal routes can reduce the severity o
f TB resulting from oral M. bovis challenge.
DESIGN: Groups of captive ferrets were vaccinated with live BCG via sub-cut
aneous injection or intra-duodenal inoculation, twice, 4 weeks apart. Vacci
nated and non-vaccinated (control) ferrets were subsequently challenged ora
lly with virulent M. bovis to simulate the natural route of infection. Peri
pheral blood lymphocyte reactivity was longitudinally monitored, and the ou
tcome of challenge was determined 20 weeks later by autopsy, histology and
bacteriological culture.
RESULT: Both vaccination routes induced tuberculin-specific lymphocyte reac
tivity; however, only the subcutaneous route was effective in reducing dise
ase. Subcutaneous vaccinated ferrets had a lower severity of infection than
non-vaccinated control animals, as indicated by significant reductions in
viable bacterial burdens and prevention of gross lesions in mesenteric lymp
h nodes (the primary site of infection), and a lower incidence of bacterial
translocation to thoracic lymph nodes. However, sub-cutaneous vaccination
did not reduce the incidence of mesenteric lymph node infection.
CONCLUSIONS: Systemic vaccination with BCG can reduce the severity of TB re
sulting from oral challenge with virulent M. bovis; however, delivery of vi
able BCG to the upper intestinal tract may not protect ferrets against TB.