Objectives

Different species of Ehrlichia (E. canis, E. ewingii, E. chaffeensis, E. platys and E. phagocytophila; the last two being recently renames as Anaplasma species) can infect dogs with variable pathogenicity. Furthermore mixed infections can occur and new methods presented in this paper helped to discriminate these canine pathogens.

Materials & Methods

DNA was extracted from EDTA-blood samples with a phenol-chloroform method. Three PCR sets were performed to specifically identify either E. canis (542bp), A. platys (556bp) or A. phagocytophila (621bp) all fragments situated on the 16S rRNA gene. A second experiment, a macro-array-based method was performed with species-specific probes for E. canis, E. chaffeensis and A. platys.

Results

One investigated kennel in Teramo (Italy) showed a canine infection rate of 23% for A. platys and no other pathogen was detected, the pathogen presence was confirmed by PCR, RLB and DNA sequencing. Another kennel showed an infection rate of 22% for A. phagocytophila while no other infection was observed.

Conclusion

The above molecular methods allowed to specifically discriminate canine Ehrlichia and Anaplasma species, which are difficult to separate with conventional methods. Such molecular methods will better help understanding the epidemiology of such pathogens and to prepare the most adapted treatment methods.