title: Sequence analysis of the msp4 gene of Anaplasma phagocytophilum strains.
abstract: The causative agent of human granulocytic ehrlichiosis was recently reclassified as Anaplasma phagocytophilum, unifying previously described bacteria that cause disease in humans, horses, dogs, and ruminants. For the characterization of genetic heterogeneity in this species, the homologue of Anaplasma marginale major surface protein 4 gene (msp4) was identified, and the coding region was PCR amplified and sequenced from a variety of sources, including 50 samples from the United States, Germany, Poland, Norway, Italy, and Switzerland and 4 samples of A. phagocytophilum-like organisms obtained from white-tailed deer in the United States. Sequence variation between strains of A. phagocytophilum (90 to 100% identity at the nucleotide level and 92 to 100% similarity at the protein level) was higher than in A. marginale. Phylogenetic analyses of msp4 sequences did not provide phylogeographic information but did differentiate strains of A. phagocytophilum obtained from ruminants from those obtained from humans, dogs, and horses. The sequence analysis of the recently discovered A. phagocytophilum msp2 gene corroborated these results. The results reported here suggest that although A. phagocytophilum-like organisms from white-tailed deer may be closely related to A. phagocytophilum, they could be more diverse. These results suggest that A. phagocytophilum strains from ruminants could share some common characteristics, including reservoirs and pathogenicity, which may be different from strains that infect humans.
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078, USA. jose_delafuente@yahoo.com
authors.forename: José
authors.initials: J
authors.lastname: de la Fuente
authors.forename: Robert F
authors.initials: RF
authors.lastname: Massung
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Wong
authors.forename: Frederick K
authors.initials: FK
authors.lastname: Chu
authors.forename: Hans
authors.initials: H
authors.lastname: Lutz
authors.forename: Marina
authors.initials: M
authors.lastname: Meli
authors.forename: Friederike D
authors.initials: FD
authors.lastname: von Loewenich
authors.forename: Anna
authors.initials: A
authors.lastname: Grzeszczuk
authors.forename: Alessandra
authors.initials: A
authors.lastname: Torina
authors.forename: Santo
authors.initials: S
authors.lastname: Caracappa
authors.forename: Atilio J
authors.initials: AJ
authors.lastname: Mangold
authors.forename: Victoria
authors.initials: V
authors.lastname: Naranjo
authors.forename: Snorre
authors.initials: S
authors.lastname: Stuen
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Kocan
mesh_terms: D000595:Amino Acid Sequence; D041081:Anaplasma phagocytophilum / Q000145:classification* / Q000235:genetics*; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D005798:Genes, Bacterial; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; C085498:Msp4 protein, Anaplasma marginale