INVESTIGADORES
ESTEIN Silvia Marcela
congresos y reuniones científicas
Título:
Experimental infection of Brucella canis in mice
Autor/es:
CLAUSSE M.; ESTEIN S.M.
Lugar:
Buenos Aires
Reunión:
Conferencia; Brucellosis 2011. International Research Conference.; 2011
Institución organizadora:
AAM
Resumen:
Experimental
infection of Brucella canis in mice
M. Clausse1,2, S.M. Estein1,3
1Laboratorio de Inmunología,
Depto de Sanidad Animal y Medicina Preventiva, Facultad de Ciencias
Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires,
Tandil, Argentina. 2ANPCyT. 3CONICET.
mclausse@vet.unicen.edu.ar.
Canine brucellosis is a reproductive infectious
disease which constitutes a serious problem not only in kennels but also in various canine populations worldwide [1]. B.
canis can also be eventually transmitted to humans. The use of a vaccine
may be the most convenient and efficacious method for the control of this
disease. Part of the limitation in testing a vaccine is the lack of a suitable
laboratory animal permissive to the infection by B. canis. Studies on
infection, transmission and pathogenia of this bacterium have been carried out
in dogs but information about vaccines is scarce. The mouse model has been
developed for determining the efficacy of vaccines against B. ovis and
smooth brucellae. The aim of this study was to evaluate mouse model for B.
canis infection with different I) doses, II) routes and III) times of sacrifice. Female 5-6 weeks old BALB/c mice were challenged
with virulent B. canis RM6/66. This strain was grown for 24 h on
Brucella agar (BA) slants. Bacteria was harvested in sterile saline,
photometrically adjusted to the desired concentration and inoculated into mice.
The exact dose expressed as colony forming unit (c.f.u) was retrospectively
determined by dilution and spreading on plates of BA. After slaughter, spleens
were aseptically removed, homogenized, serially diluted, and plated. Colonies
were counted after incubation at 37°C
for 72 h and the results were represented as the mean log c.f.u. ± standard
deviation (SD) per group. Mice were randomly
distributed in different groups and were inoculated using following
protocols: I) intraperitoneal (i.p.) inoculation with
tenfold dilution starting at 7x102 up to 7x107c.f.u.,
respectively and slaughter 30 days after
challenge, II) intravenous (i.v.) or i.p. routes with 2.6x105,
2.6x106, or 2.6x107 c.f.u. and kill 30 days after inoculation and III) i.p. inoculation
with 1.2x106 or 1.2x107c.f.u.
and sacrifice at 7, 14, 21 and 30 days post-inoculation. The results showed
that bacterial burden per spleen increased significantly when increasing the
dose up to 7x105. After this dose, counts reached a plateau phase.
No colonies were isolated when the minimum dose (7x102) was
inoculated. Spleen infection of mice inoculated i.v. or i.p. did not show
statistical differences for the doses used. Most mice would reach splenic
infection after 2 weeks and the bacterial counts were maintained at least up to
day 30. Our results are consistent with the kinetics of other Brucella strains
infection in mice [2,3]. Mouse is a promising model to evaluate vaccines
against B. canis. [ 1 ] Wanke M.M.
2004. Reproduction Science [ 2 ] Jiménez de Bagüés M.P. et al. 1993. Vaccine [ 3 ] Bosseray N. et al. 1982. Ann. Rech. Vet.