Fine-Structure of Haemobartonella canis (Rickettsiales: Bartonellacea) and Its Relation to the Host Erythrocyte

Abstract

Haemo-bartonella canis is a simple organism that adheres to, but does not penetrate, the plasmalemma of the canine erythrocyte. Individual organisms appear either as coccoids, rings, or rods. These aggregate most commonly into chains, less commonly into small planar groups. Single organisms dimple the surface of the host erythrocyte while aggregates produce grooves or deep infoldings in it. Each organism is bounded by a single membrane that encloses a dense matrix of macro -molecular aggregates. Granular aggregates ranging between 100 and 200 A in size, possibly linking into chains, make up the majority of the matrix.