Rickettsia diseases are caused by small intracellular Gram-negative rod-shaped bacteria that are members of the
order Rickettsiales and family Rickettsiaceae in the Proteobacteria [alpha]-subdivision (RAOULT & ROUX, 1997; DUMLER et al., 2001).
Reorganization of genera in the families Rickettsiaceae and Anaplasmataceae in the
order Rickettsiales: unification of some species of Ehrlichia with Anaplasma, Cowdria with Ehrlichia and Ehrlichia with Neorickettsia, descriptions of six new species combinations and designation of Ehrlichia equi and 'HGE agent' as subjective synonyms of Ehrlichiaphagocytophila.
These three pathogen species belong to Anaplasmataceae family and
order Rickettsiales. They have a 97% similarity in their 16S rRNA sequence and they also share similar immunogenic epitopes [8-13].
marginale), of
order Rickettsiales, family anaplasmataceae.
Recent taxonomic changes have reclassified the families Rickettsiaceae and Anaplasmataceae in the
order Rickettsiales with the unification of some species of Ehrlichia under the unique species Anaplasma phagocytophilum [2].
phagocytophilum of the
order Rickettsiales is a Gram-negative bacterium that invades neutrophils [1,2].
Bovine anaplasmosis (BA) is caused by obligate intraerythrocytic rickettsia of the
order Rickettsiales, family Anaplasmataceae, genus Anaplasma (Dumler et al, 2001) characterized by fever, weight loss, decreased milk production, pale mucous membranes, severe anaemia, jaundice, brownish urine, hyper-excitability abortion and mortality without hemoglobinemia and hemoglobinuria during acute phase of the infection (Richey and Palmer, 1990).
The genus Rickettsia includes bacteria of the
order rickettsiales in the alpha subdivision of the class Proteobacteria.
Anaplasmosis is a disease of cattle and other ungulates caused by Anaplasma marginale, an ehrlichial member of the
Order Rickettsiales [5].
Canine ehrlichiosis is a tick borne disease caused by Ehrlichia canis, an obligate intracellular rickettsia of genera Ehrlichia, family Anaplasmatacea and
order Rickettsiales (Price and Sayer, 1983).
