The Journal of Medical Microbiology, Vol 15, Issue 1 105-116, Copyright © 1982 by Society for General Microbiology
Virulence of Bordetella bronchiseptica from pigs with or without atrophic rhinitis
J. M. Rutter, L. M. Francis and B. F. Sansom
The virulence of 17 isolates of Bordetella bronchiseptica from 13 pig herds
was compared by intranasal infection of gnotobiotic piglets and LD50 tests
on mice. Of 59 piglets given 8.1-10-5 log 10 colony-forming units (cfu) of
isolates from two herds with atrophic rhinitis (AR isolates) or isolates
from six unaffected herds (non-AR isolates), 16 died of acute pneumonia;
the survivors developed non-progressive turbinate hypoplasia and chronic
pneumonia. Infection of 11 piglets with c. 3.0 log to cfu of three AR
isolates or three non-AR isolates caused turbinate hypoplasia, but only
slight pneumonia and no deaths. There were no significant differences
between the virulence of AR and non-AR isolates in piglets. In LD50 tests
in mice, there were no significant differences between the results from six
AR isolates and six non-AR isolates, or from toxin prepared from two AR
isolates and one non-AR isolates was fairly uniform, and that other factors
must be responsible for the occurrence of progressive lesions of atrophic
rhinitis in some but not all infected herds.
