Transmission and passage in horses of the agent of human granulocytic ehrlichiosis.
The human granulocytotropic ehrlichia and Ehrlichia equi produce similar diseases in their respective host species (humans, horses). Currently, the phylogenetic and biologic relationships of these 2 uncultured pathogens remain unclear. Previous studies have revealed nucleotide sequence similarity approaching identity at the level of the 16S ribosomal RNA gene. To investigate the biologic similarities of these 2 ehrlichiae, the susceptibility of horses to the human agent was tested by intravenous inoculation of infected human blood. The results demonstrate that the human granulocytotropic ehrlichia produces a disease in the horse indistinguishable from that caused by E. equi, providing biologic evidence that these 2 organisms are highly related and potentially conspecific. It is possible that cases of human illness now attributed to human granulocytotropic ehrlichia may in fact be caused by 1 or more strains of an ehrlichia known chiefly as an equine pathogen.
Madigan
J E
JE
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616-8737, USA.
Richter
P J
PJ
Kimsey
R B
RB
Barlough
J E
JE
Bakken
J S
JS
Dumler
J S
JS
D000368:Aged; D000818:Animals; D001483:Base Sequence; D001772:Blood Cell Count; D004275:DNA, Ribosomal / Q000235:genetics; D004536:Ehrlichia / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D016873:Ehrlichiosis / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D005260:Female; D005334:Fever; D006098:Granulocytes / Q000382:microbiology* / Q000473:pathology; D006734:Horse Diseases / Q000382:microbiology*; D006736:Horses; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000382:microbiology / Q000473:pathology; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S