Antigenic diversity of granulocytic Ehrlichia isolates from humans in Wisconsin and New York and a horse in California.
The agent of human granulocytic ehrlichiosis (HGE), Ehrlichia phagocytophila, and Ehrlichia equi are very similar. HGE is of variable severity. Genetic and antigenic differences among 3 human isolates (Webster, Spooner, and NY-8) and 1 horse isolate (MRK) were evaluated. The 16S rRNA gene sequences were identical in all human isolates. By use of 5 homologous antisera from these 3 humans and 1 horse and an additional 5 antisera in heterologous reactions, the immunodominant antigens of each isolate were noted to differ in molecular size: 43 kDa in the Webster (Wisconsin) isolate, 46 kDa in the Spooner (Wisconsin) isolate, 42 and 45 kDa in the NY-8 (New York State) isolate, and a 42 kDa doublet in the E. equi MRK isolate from California. Two sera from a Wisconsin patient reacted weakly or not at all with the NY-8 isolate. Antigenic structural diversity exists among otherwise indistinguishable granulocytic ehrlichial isolates.
Asanovich
K M
KM
Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA.
Bakken
J S
JS
Madigan
J E
JE
Aguero-Rosenfeld
M
M
Wormser
G P
GP
Dumler
J S
JS
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D000942:Antigens, Bacterial / Q000032:analysis*; D003429:Cross Reactions / Q000276:immunology; D004269:DNA, Bacterial / Q000032:analysis; D004536:Ehrlichia / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D016873:Ehrlichiosis / Q000097:blood / Q000235:genetics* / Q000276:immunology*; D006736:Horses; D006801:Humans; D015151:Immunoblotting; D016056:Immunodominant Epitopes / Q000032:analysis; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D004269:DNA, Bacterial; D016056:Immunodominant Epitopes; D012336:RNA, Ribosomal, 16S