EHRLICHIA-LIKE 16S RDNA SEQUENCE FROM WILD WHITE-TAILED DEER (ODOCOILEUS-VIRGINIANUS)

The reservoir hosts of Ehrlichia chaffeensis, etiologic agent of human ehrlichiosis are unknown. Initially, white-tailed deer (WTD) were ser ologically implicated as possible reservoirs of E. chaffeensis. Subseq uent studies showed that WTD were susceptible to infection with E. cha ffeensis and that deer-to-deer transmission by a tick vector, Amblyomm a americanum, is possible under experimental conditions. To determine if wild WTD were infected with E. chaffeensis, whole blood was collect ed from 10 deer from Oklahoma and Georgia. All 10 deer had antibodies reactive to E. chaffeensis. Whereas E. chaffeensis was not isolated, r estriction enzyme mapping and sequencing of the 16S rDNA gene revealed that a unique Ehrlichia-like agent was present. All 10 deer appeared to be infected with the same agent. We suspect that A. americanum is t he vector of this new agent based upon the previously published tempor al association between the appearance of E. chaffeensis seropositive W TD and A. americanum. However, the taxonomic and antigenic relationshi ps, geographic distribution, epidemiology, and zoonotic potential of t his agent are yet to be determined.