Morphology and staining characteristics of Ehrlichia bovis.

Morphology and staining characteristics of Ehrlichia bovis were observed after staining with Romanowsky and Gimenez stains and fluorochroming with acridine orange. Ehrlichia bovis could be identified as elementary bodies, initial bodies and morulae in the host cell cytoplasm. The inclusions were solid and compact and resembled more closely those of E. canis (canine monocytic ehrlichia) than E. phagocytophilia or E. ondiri (bovine granulocytic ehrlichiae). The organisms usually took acidophilic shades with Romanowsky stains. Apart from morulae, the other forms sometimes resembled azurophil granules. While Gimenez staining and fluorochroming by Anderson and Greiff technique gave poor results, the organism stained well on fluorochroming with Lauer's technique.