In vitro Culture of a Novel Genotype of E hrlichia sp. from B razil

Summary Ehrlichiae are obligate intracytoplasmic Gram‐negative, tick‐borne bacteria belonging to the Anaplasmataceae family. Ehrlichioses are considered emerging diseases in both humans and animals. Several members of the genus E hrlichia have been isolated and propagated in vitro . This study describes the continuous propagation of a B razilian E hrlichia sp. isolate in IDE8 tick cells, canine DH 82 cells and bovine aorta cells. Initially, the organisms were isolated from the haemolymph of a R hipicephalus ( B oophilus ) microplus tick into IDE 8 cells. Infected IDE 8 cells were brought from B razil to G ermany, where the organisms were continuously propagated in IDE 8, DH 82 and bovine aorta cells. Bovine aorta cells were infected and propagated for 3 months, corresponding to six subcultures, whereas the other two infected cell lines were kept for more than 1 year. During the cultivation period, 36 and 14 subcultures were carried out in IDE 8 and DH 82 cell cultures, respectively. Reinfection of IDE 8 cells with organisms grown in DH 82 cells was achieved. Sequence analysis made with a fragment of the 16S rRNA gene showed that this E hrlicha sp. is closely related to E hrlichia canis . However, the maximum likelihood phylogenetic tree shows that it falls in a separate phylogenetic clade from E . canis .