Molecular detection of Rickettsia species in ticks collected from cattle, with a note on the first molecular report of Rickettsia conorii subsp. israelensis in Türkiye

Erol U., Şahin Ö. F., Kalın R., Urhan O. F., Şakar H. F., Altay K.

COMPARATIVE IMMUNOLOGY, MICROBIOLOGY AND INFECTIOUS DISEASES, sa.129, ss.1-10, 2026 (SCI-Expanded, Scopus)

Özet

Türkiye is a country where several vector species can survive due to its diverse climate and geographical features. To date, several vector-borne pathogens that threaten human and animal health, including Rickettsia spp., have been detected in various hosts throughout the country. The aim of this study was to investigate the presence and prevalence of Rickettsia species in cattle and in ticks collected from cattle using molecular methods and to perform phylogenetic analyses of positive samples. For this purpose, blood and tick samples were collected from 433 cattle from different regions of Türkiye and researched for Rickettsia. The PCR results revealed no pathogen DNA in the cattle blood samples. Seven tick species, Hyalomma marginatum, Hyalomma anatolicum excavatum, Rhipicephalus bursa, Rhipicephalus annulatus, Rhipicephalus turanicus, Ixodes ricinus, and Dermacentor marginatus, were identified in this study. A total of 64 tick pools were prepared from these ticks, and Rickettsia DNA was detected in 43.75% (28/64) of the pools. DNA sequence analyses of the ompA, ompB, and gltA gene regions were performed to identify the Rickettsia species detected in PCR-positive samples and to determine their phylogenetic features. Five Rickettsia species were identified: Rickettsia aeschlimannii (n = 16), Candidatus Rickettsia barbariae (n = 7), Rickettsia sibirica subsp. mongolitimonae (n = 2), Rickettsia conorii subsp. israelensis (n = 2), and Rickettsia slovaca (n = 1) The consensus sequences obtained for each gene region were deposited in GenBank, and accession numbers were assigned. In addition, this study represents the first molecular detection of Rickettsia conorii subsp. israelensis in Türkiye. The findings indicate that Rickettsia species are widely distributed in ticks collected from cattle in Türkiye. Considering that the identified species pose a potential threat to both human and animal health, physicians and veterinarians in the study area should remain vigilant and implement appropriate surveillance and control programs.