Molecular Detection of Tick-Borne Rickettsial Pathogens Associated with the Arabian Camel (Camelus dromedarius) in Riyadh and the Eastern Region, Saudi Arabia

Background In Saudi Arabia, records on molecular identification of tick-borne infections in camels are relatively scarce; few molecular epidemiological studies have been conducted. Objective This study aimed to find Anaplasma species and Piroplasma spp. in camels from Riyadh and the Eastern Region, Saudi Arabia. Animals A total of 1369 blood samples were collected from camels from Riyadh and the Eastern Region and analyzed for the DNA of Anaplasma and Piroplasma species by polymerase chain reaction (PCR). Results Piroplasma spp. infection was not observed in any of the blood samples. 616 camels (44.99%) were found to be positive for Anaplasma infection by PCR targeting the 16S rRNA and COX1 genes. Six Anaplasma sequences for the 16S rRNA gene (OK481101-OK481106) were deposited in GenBank and six for the COX1 gene (OK490994-OK490999). They showed 98.3% and 62.7% similarities with Anaplasma marginale (A. marginale) detected in Kenya and Brazil, respectively. Phylogenetic studies revealed that the 12 sequences reported in this study were closely related; they were found in the same cluster as A. marginale isolates previously recorded in South Africa, Brazil, USA, China, and Israel. Conclusion Finally, 12 Anaplasma sequences closely related to A. marginale were detected in camels in Riyadh and the Eastern Region, Saudi Arabia. Camels in these areas were confirmed to be free of Piroplasma.

Automated summary

This study identified Anaplasma species and Piroplasma spp. in camels from Riyadh and the Eastern Region, Saudi Arabia. The results showed that no Piroplasma spp. infection was observed, but 44.99% of the camels were positive for Anaplasma infection. Phylogenetic analysis revealed that the Anaplasma sequences closely related to A. marginale were detected in camels from these regions.