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. 1998 Dec 1;39(4):491–497. doi: 10.1186/BF03547775

Experimental Infection of Lambs with an Equine Granulocytic Ehrlichia Species Resembling the Agent that Causes Human Granulocytic Ehrlichiosis (HGE)

S Stuen 110,✉, K Artursson 210, E Olsson Engvall 210
PMCID: PMC8050659  PMID: 9926463

Abstract

Five lambs were inoculated with a granulocytic Ehrlichia species originally isolated from a Swedish horse with granulocytic ehrlichiosis (EGE). The 16S rRNA gene sequence of the Swedish Ehrlichia sp. causing EGE was identical to the sequence of the agent causing human granulocytic ehrlichiosis (HGE). After the inoculation, infected neutrophils and a low serologic response were seen in all lambs, but no clinical symptoms were observed. In one lamb 17% of the neutrophils were infected without a corresponding fever. Six weeks later the lambs were inoculated with an ovine isolate of E. phagocytophila. After challenge with E. phagocytophila the lambs reacted with fever and infected granulocytes. The results presented herein show that the equine Ehrlichia isolate was infective for lambs but generated weak immune response and no distinctive protection from subsequent challenge with E. phagocytophila.

Keywords: E. phagocytophila, antibodies, immunity

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Acknowledgement

The authors want to thank Ulla-Britt Wikstrøm for excellent technical assistance.

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