Cultivation of Ehrlichia canis in a continuous BALB/C mouse macrophage cell culture line

This report describes the successful adaptation of the Israeli isolate of Ehrlichia canis on a continuous mouse macrophage cell line (J774.A1). Successful infection of the J774.A1 cells was first judged by the direct immunofluorescence antibody test using an anti-E. canis-IgG:FITC conjugate. A particular property of infected J774.A1 cells was the ability to reestablish after harvesting of the monolayer by scaping. Infected cells were used as antigen for immunofluorescence antibody tests (IFA), and the results compared well with those of DH82 cells. It was concluded that the J774.A1 continuous cell line could serve as an alternate propagation cell line for E. canis organisms.