[Molecular tools in the epidemiology of tick-borne bacterial diseases].

Molecular tools have been used to detect rickettsiae in ticks. In Ixodes ricinus ticks collected in France, we detected for the first time there an emerging pathogen, Rickettsia helvetica, and an Ehrlichia sp, closely related to the agent of human granulocytic ehrlichiosis. In Guadeloupe (French West Indies), we described the occurrence of African tick-bite fever due to Rickettsia africae, which had been previously reported in sub-Saharan Africa only. In Africa, we completed our knowledge about the distribution of R. africae (Mali, Niger, Sudan, Burundi), and detected for the first time Rickettsia mongolotimonae, an emerging pathogen. Anaplasma marginale the agent of bovine anaplasmosis was detected in Mali. Rickettsiae of unknown pathogenicity were detected in Mali and Niger.