Adhesion of type A Pasteurella mulocida to rabbit pharyngeal cells and its possible role in rabbit respiratory tract infections.
ABSTRACT
Pasteurella multocida serotype A was found
in association with the mucosal epithelium of the nasopharynges of
rabbits with
respiratory tract infections. The bacteria
specifically attached to squamous epithelial cells of the pharyngeal
mucosa both
in vivo and in vitro and to some tissue culture
cell lines such as HeLa. All strains with serotype A capsules were
adhesive.
With the exception of one serotype D strain,
strains with capsular serotypes B, D, and E were at least 10-fold less
adhesive.
Bacterial adhesiveness was much reduced after
pronase digestion, heat treatment, and homogenization, but removal of
the hyaluronic
acid capsule increased adhesion. Electron
microscopy revealed that fimbriae were produced by an adhesive
pasteurella strain,
but not by two nonadherent strains. The attachment
of the former strain to pharyngeal and HeLa cells was inhibited by
N-acetyl-D-glucosamine.
Together, these findings suggest that this amino
sugar may be a component of the receptor on both animal cell surfaces
and
that the fimbriae may be the adhesions. It is
proposed that bacterial attachment has a role in colonization and
infection
of rabbit upper respiratory mucosae.
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