Molecular Investigation on Tick-Borne Hemoparasites and Coxiella burnetii in Dromedary Camels (Camelusdromedarius) in Al Dhafra Region of Abu Dhabi, UAE

Abstract

Camels represent an important resource for inhabitants of the most arid regions of the world and their survival is mainly related to environment conditions including the risk of parasitic diseases, which may represent a significant cause of losses in livestock production of these areas. Camels may be parasitized by several hematophagous arthropods, which can be vectors of several diseases including zoonosis. This study aimed to investigate in dromedary camels and their ticks the importance of tick-borne hemoparasites that might be responsible for a recent and obscure morbidity of camels in Al Dhafra region of Abu Dhabi, UAE. Blood samples and ticks from 93 naturally infected camels belonging to 36 herds, affected by variable acute clinical syndromes lasting from 3 to 5 days, were analyzed through molecular techniques for specific DNA presence of different blood pathogens: Anaplasmamarginale/Anaplasmaovis, Anaplasma phagocytophilum, Coxiella burnetii,Babesia spp., and Theileria spp. DNA. All the 72 ticks collected belonged to the Hyalomma dromedarii species and were negative for blood pathogens. n = 15 camels (16.1%) were found positive to the following tick-borne hemoparasites: A. phagocytophilum 11 (11.8%), Coxiella burnetii 3 (3.2%), and Babesia/Theileria spp. 2 (2.1%). One singular camel showed coinfection of C. burnetii and A. phagocytophiulm. Genetic profile of C. burnetii showed a high phylogenetic relatedness to European, Asian and African C. burnetii strains. This is the first laboratory investigation on tick-borne pathogens in camels in UAE, and the first report of A. phagocytophilum and C. burnetii. Moreover, since the detected pathogens are recognized pathogens for humans, this study highlights the zoonotic risk for humans working in camel husbandry.

Tissue-specific localization of tick-borne pathogens in ticks collected from camels in Kenya: insights into vector competence

“…(i.e., A. marginale, A. platys , and A. ovis ) were detected in apparently healthy camels. Anaplasma spp., including A. phagocytophilum , have previously been detected in camels from Saudi Arabi ( Alanazi et al., 2020 ), Algeria ( Bessas et al., 2022 ), and the United Arab Emirates ( El Tigani-Asil et al., 2021 ). Further, in Ben Said et al.…”

Molecular Detection of Candidatus Anaplasma camelii in Naturally Infected Dromedary Camels (Camelus dromedarius) in Abu Dhabi Emirate, United Arab Emirates, 2019–2023

“…The level of infection of Anaplasmataceae varies between different studies conducted in different regions. In the UAE, Anaplasma phagocytophilum was molecularly identified in samples collected from camels showing acute clinical signs ranging from anemia, weakness, fever, anorexia, lymph node hyperplasia with perilymphatic tissue, generalized ventral edema, and recumbency to death [ 16 ]. Other researchers in the Taif and Unizah regions of Saudi Arabia recorded more than 30% of Anaplasmataceae infections in camels [ 21 ].…”

“…Anaplasmosis adversely affects livestock health and performance, causing an average cost of USD 793 per head of cattle, 54% of which can be attributed to death, followed by 15% attributable to disease treatment, 14% to weight loss, 8% to chronic disease, and 9% to abortion. So far, five species of Anaplasma have been detected in dromedary camels including A. phagocytophilum [ 15 , 16 ], A. platys [ 17 , 18 ], A. ovis [ 19 ], A. marginale [ 19 , 20 ], and Candidatus A. camelii (genetically close to A. platys ), recently detected in dromedary camels in Saudi Arabia [ 21 , 22 ], Iran [ 23 ], Morocco [ 14 ], and Kenya [ 24 , 25 ]. However, their veterinary and economic importance in camel is still not well clarified, and more applied research is needed, especially in the fields of pathogenicity and pathogenesis, to uncover the clinical role of such parasites in camel health and production.…”

Recent Advances on the Innate Immune Response to Coxiella burnetii

“…These models have been essential to comprehend C. burnetii intracellular replication and the host cell response to the infection ( Voth and Heinzen, 2007 ; van Schaik et al., 2013 ). Other animal species (e.g., dogs, lions, and camels; Torina et al., 2007 ; Hornok et al., 2013 ; El Tigani-Asil et al., 2021 ) are susceptible to C. burnetii but have not been used as experimental models. Coxiella- related tick endosymbionts have also been identified as microbiota component of some tick species ( Díaz-Sánchez et al., 2019 ).…”