Molecular detection of Rickettsia and Ehrlichia isolates inticks collected from domestic livestock of Torbat Heydariyeh-Iran-۲۰۲۰-۲۱

Background and Aim : Ticks belong to the spider class and Acarina subfamily and are mandatoryblood-sucking external parasites affecting birds, mammals, reptiles and amphibians and are aneconomic and health problem in tropical and subtropical regions of the world. Ticks are veryimportant vectors for the transmission of bacterial pathogens such as Rickettsiae spp. and Ehrlichiaspp. The study and diagnosis of these pathogens can play an important role in disease preventingand human health promotion. In this study, the molecular screening of Rickettsiae spp. andEhrlichia spp. from ticks in domestic livestock was investigated in Torbat Heydariyeh, Iran, ۲۰۲۱.Methods : ۲۰۰ isolated ticks were collected from domestic livestock in Torbat Heydariyeh during۲۰۲۰-۲۰۲۱, stored in ۷۰% ethanol, and transferred to the laboratory and stored at -۲۰. The genusand species of ticks were identified using a stereo-microscope according to morphologicalparameters. DNA was extracted and Rickettsiae spp. and Ehrlichia spp. were identified usingprimers aimed to ompA and ۱۶S rRNA by PCR technique.Results : The genus identification of ticks revealed high diversity, with ۲ genera and ۹ specieswere identified. Among these, the distribution of Rhipicephalus Sanguineus and Hyalommamarginatum was ۴۶% and ۱۷%, respectively. On the other hand, the prevalence of Rickettsiae spp.and Ehrlichia spp. in ۲۰۰ ticks were ۵۸ (۲۹%) and ۳۶ (۱۸%), respectively. Sequencing resultsshowed that the amplified ompA and ۱۶S rRNA genes belonged to R. aeschlimannii and Ehrlichiaspp, respectively. Both bacteria were isolated from Rhipicephalus Sanguineus.Conclusion : Since ticks play an important role in the transmission of pathogens, and also highprevalence of Rickettsiae spp. and Ehrlichia spp. was identified in the collected ticks, the attentionof health officials and the development of control programs seem necessary. Furthermore, it issuggested to expand the current study to recognition of the species and strain of the identifiedbacteria, as well as other tick-related pathogens in our region.

Keywords:

Ticks , Rickettsia , Ehrlichia