Four Tick-Borne Microorganisms and Their Prevalence in Hyalomma Ticks Collected from Livestock in United Arab Emirates

Abstract

Ticks and associated tick-borne diseases in livestock remain a major threat to the health of animals and people worldwide. However, in the United Arab Emirates (UAE), very few studies have been conducted on tick-borne microorganisms thus far. The purpose of this cross-sectional DNA-based study was to assess the presence and prevalence of tick-borne Francisella sp., Rickettsia sp., and piroplasmids in ticks infesting livestock, and to estimate their infection rates. A total of 562 tick samples were collected from camels, cows, sheep, and goats in the Emirates of Abu Dhabi, Dubai, and Sharjah from 24 locations. DNA was extracted from ticks and PCR was conducted. We found that Hyalomma dromedarii ticks collected from camels had Francisella sp. (5.81%) and SFG Rickettsia (1.36%), which was 99% similar to Candidatus Rickettsia andeanae and uncultured Rickettsia sp. In addition, Hyalomma anatolicum ticks collected from cows were found to be positive for Theileria annulata (4.55%), whereas H. anatolicum collected from goats were positive for Theileria ovis (10%). The widespread abundance of Francisella of unknown pathogenicity and the presence of Rickettsia are a matter of concern. The discovery of T. ovis from relatively few samples from goats indicates the overall need for more surveillance. Increasing sampling efforts over a wider geographical range within the UAE could reveal the true extent of tick-borne diseases in livestock. Moreover, achieving successful tick-borne disease control requires more research and targeted studies evaluating the pathogenicity and infection rates of many microbial species.

Prevalence, Distribution, and Molecular Record of Four Hard Ticks from Livestock in the United Arab Emirates

“…This tick is the competent vector of CCHF [49] and poses a serious threat to livestock, as well as humans, who may be exposed to tick bites in the livestock industry. In the UAE, this species was found to be a carrier of CCHF [7], T. annulata and Theileria ovis [50].…”

The Symbiotic Continuum Within Ticks: Opportunities for Disease Control

“…FLEs are assumed to be non-pathogenic to humans, though they may cause limited pathogenicity in small animals ( Keim et al, 2007 ) and are found in human-biting ticks, including those belonging to the genera Dermacentor , Amblyomma , Ixodes , and Hyalomma ( Scoles, 2004 ; Machado-Ferreira et al, 2009 ; Ivanov et al, 2011 ; de Carvalho et al, 2016 ; Azagi et al, 2017 ). Presence of the genus Francisella has been reported in the camel tick, Hyalomma dromedarii , through 16s rRNA sequencing, with high relative abundance (99%) ( Perveen et al, 2020b ) and subsequent PCR confirming close relation to FLE ( Perveen et al, 2021a ). In the same geographic area, H. dromedarii ticks were reported throughout the year with high prevalence (94%) ( Perveen et al, 2020a ).…”

“…As a taxonomic group, ticks are well-adapted to a wide range of climatic conditions, thriving in tropical, temperate and even subarctic habitats ( Anderson and Magnarelli, 2008 ). Ticks (Acari: Ixodida) are divided into three families: Ixodidae, Argasidae, and Nuttalliellidea ( Anderson and Magnarelli, 2008 ; Perveen, 2021 ), and almost 28 tick species have been reported to transmit pathogens to humans ( Anderson and Magnarelli, 2008 ). The prevalence of many tick-borne pathogens, such as Babesia , Theileria , and Borrelia has increased in recent years due to climate change and other anthropogenic factors such as land use change, deforestation, urbanization, global travel, and trade ( Rochlin and Toledo, 2020 ).…”

Microbial composition in Hyalomma anatolicum collected from livestock in the United Arab Emirates using next-generation sequencing

“…Hyalomma anatolicum , a widely distributed tick species that occurs worldwide, is the main vector of piroplasmids, including Theileria annulata , T. lestoquardi , T. equi and Babesia caballi , as well as Crimean-Congo hemorrhagic fever virus [ 4 ]. In a recent study, H. anatolicum in the United Arab Emirates (UAE) was found to be infected with T. annulata and Theileria ovis [ 5 ].…”

“…Numerous studies have been carried out on the microbiome of ticks infesting livestock [ 6 , 18 , 19 ]. In the UAE, ticks are a continuous problem in livestock [ 5 ], particularly in camels. In a study conducted in 2019–2020, the camel tick, Hyalomma dromedarii , was found on camels throughout the year [ 20 ].…”