A molecular survey was undertaken to determine the presence of protozoal and bacterial organisms in 120 ticks and 87 blood samples collected from mammals in northeastern Algeria. Eight tick species were morphologically identified including 70 Rhipicephalus (Boophilus) annulatus,23 Rhipicephalus bursa, five Rhipicephalus sanguineus sensu lato, 11 Hyalomma impeltatum, five Hyalomma scupense, two Hyalommma marginatum, one Hyalomma anatolicum and three Ixodes ricinus. Quantitative PCR screening of the ticks showed that Theileria annulata, "Candidatus Ehrlichia urmitei", Theileria buffeli and Anaplasma platys were detected in Rh. annulatus. Rickettsia massiliae and Anaplasma ovis were detected in Rh. sanguineus s.l. and Rh. bursa. Rickettsia aeschlimannii was detected in Hy. marginatum, Hy. scupense and Hy. impeltatum. Finally, "Candidatus Rickettsia barbariae" was detected in Rh. bursa. In the screening blood samples, Theileria equi, T.annulata, T. buffeli, Babesia bovis, Anaplasma marginale, A. ovis and Borrelia spp. were detected in cattle. Theileria ovis, T. annulata, and A. ovis were detected in sheep. In addition, A. ovis and T. equi were detected in goats and equidea respectively. In this study, T. equi and "Candidatus Rickettsia barbariae" were identified for the first time in Algeria as well as potential new species of Ehrlichia and Anaplasma. Although molecular detection does not indicate vector/reservoir competence when investigating ticks removed from animals, this study expands the knowledge of the microorganisms detected in ticks in northeast of Algeria.

An analysis was conducted on the arthropod fauna collected from stork, swallow, and pigeon nests during summer 2018 in three regions of north-eastern Algeria (Guelma, El-Tarf, and Annaba). A total of 40 nests was examined, of which 58% were infested with arthropods. Arthropods were less abundant and species rich in swallow nests than in pigeon or stork nests, where a greater dominance of mesostigmatic mites (78.71% and 72.41%, respectively) was found. Dermanyssus gallinae was the most abundant (33.05%) and most frequent (73.33%) mesostigmatic mite in pigeon nests, while uropodina mites were dominant (41.37%) in white stork nests with a frequency of 76.92% of the nests analysed. In swallow nests, the following arthropods were found: Psocodea, Hemiptera, Hymenoptera and Coleoptera belonging to the class Insecta and Isopoda belonging to the class Malacostraca. This is the first comparative survey of arthropods occupying the nests of these bird species in northern Algeria. It is anticipated that these data, that highlight the richness of the arthropod fauna in the nests of these bird species, will motivate further research aimed at characterising the arthropod community in different bird nests and determining the nature of the relationships between them.