Anaplasma, Ehrlichia, and "Candidatus Neoehrlichia" bacteria: pathogenicity, biodiversity, and molecular genetic characteristics, a review.

The family Anaplasmataceae includes gram-negative obligate intracellular alphaproteobacteria, which amplify within membrane-bound vacuoles. The genera Anaplasma and Ehrlichia as well as the recently specified cluster "Candidatus Neoehrlichia" comprise all bacteria of the family that are transmitted by ixodid ticks to mammalian hosts and cause infections in humans and numerous domestic and wild animal species. Totally, six Anaplasma, five Ehrlichia, and two "Candidatus Neoehrlichia" species as well as a variety of Ehrlichia bacteria with undefined taxonomic position belong to tick-borne bacteria. This review briefs the ecology, pathogenic properties, and molecular genetic diversity of Anaplasmataceae validated species, "Candidatus" species, and undefined novel Ehrlichia genetic variants.