Morphological and molecular characterization of ixodid tick vectors in Algeria, North Africa

Ticks are hematophagous ectoparasites of veterinary and medical importance, serving as vectors for a wide array of pathogens that affect livestock, wildlife, and humans. Given their role in pathogen dissemination, this study aimed to provide an updated molecular characterization and phylogenetic analysis of hard tick species in Algeria using two mitochondrial markers: Cytochrome c oxidase subunit 1 (Cox1) and the 12S rRNA gene. We analyzed fourteen tick species from the archival collection of the Pasteur Institute of Algeria, originally collected from various provinces across the country. These included Dermacentor marginatus, Haemaphysalis punctata, Hyalomma aegyptium, H. dromedarii, H. excavatum, H. impeltatum, H. lusitanicum, H. marginatum, Ixodes inopinatus, I. ricinus, I. ventalloi, Rhipicephalus (Boophilus) annulatus, Rh. bursa, and Rh. sanguineus. Sequence data were compared to existing GenBank records. Phylogenetic and phylogeographic analyses revealed the sympatric distribution of I. inopinatus and I. ricinus, as well as the first report of I. ventalloi in rabbits from Northern Algeria. Moreover, several unique Algerian haplotypes were identified for both markers, particularly in D. marginatus, H. punctata, H. aegyptium, H. excavatum, H. impeltatum, H. marginatum, I. inopinatus, I. ricinus, I. ventalloi, Rh. annulatus, Rh. bursa, and Rh. sanguineus. PCR-based pathogen screening detected Coxiella burnetii and Rickettsia africae in H. dromedarii, C. burnetii and R. aeschlimannii in H. impeltatum, and Rickettsia spp. in I. ricinus. These findings underscore the importance of ongoing surveillance to more accurately delineate tick species distributions and their vectorial roles in Algeria.