RESUMEN
Livestock and their ectoparasites are involved in the epidemiology of several zoonotic diseases. Studies regarding the molecular detection of infectious agents in ticks from Northwestern Algeria are scarce. Thus, the presence of spotted fever group Rickettsia spp., Anaplasmataceae microorganisms and Coxiella burnetii was investigated in ticks collected from ruminants in Sidi Bel Abbes and Saida provinces. Rickettsia aeschlimannii was detected in one Hyalomma excavatum pool and one H. marginatum pool. Moreover, 'Candidatus Rickettsia barbariae' was found in one H. excavatum and six Rhipicephalus bursa pools. Lastly, Coxiella burnetii was amplified in two H. excavatum and two R. bursa pools. No Anaplasmataceae bacterium was detected. This study demonstrates the presence of the tick-associated microorganism 'Candidatus R. barbariae' in the North of Africa, and corroborates the presence of the zoonotic pathogens R. aeschlimannii and C. burnetii in Algeria.