Molecular Diagnosis of Rickettsiae Infecting Camels and Ixodid Ticks in Egypt

Abstract

Rickettsioses including their pathogens, vectors, and hosts have an epidemiological importance and zoonotic importance. The objective of the present article was to define the prevalence and genotypic properties of Rickettsia in camels and their ticks in Egypt. Sixty one blood samples and 99 adult ticks were taken from camel hosts from Cairo, Giza and Sinai, during a period extending from 2013 to 2014. Based on the morphological identification of both male and female tick specimens, 91.9 % of the collected ticks were Hyalomma dromedarii. The prevalence of Rickettsia in camels using Gimenez staining technique and PCR was 0 and 41 %, respectively. The rickettsiae infection in ticks recorded 10.1 and 1.01 %, by Gimenez stain and PCR, respectively. Further, the phylogenetic analysis was conducted based on the sequences of OmpA and gltAgenes and three intergenic spacers (mppA, dksA and rpmE) of Rickettsia species. The phylogenetic analyses revealed a novel strain of Rickettsia africae in Hyalomma marginatum that was collected from camel in Sinai province. In addition, the phylogenetic analysis based on Clustal omega suggested that Rickettsia sequences which detected in camels were R. africae. Moreover, the highest Rickettsial infection rate was recorded in age groups of 17 to 19 years (80.0 %), Abady camel breeds (56.8 %) and ticks-infested camels (42.8 %). Concerning hematological changes, macrocytic anemia and leucopenia were recorded in camels with rickettsioses. The molecular characterization of Rickettsia detected in camels and their tick vectors will help in a better understanding of the epidemiological approach of rickettsioses in Egypt.

Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels ( Camelus dromedarius ) and their infesting ticks from Tunisia

“…was identified in both H. dromedarii (8%) and H. impeltatum (10.4%) ticks that are considered as the main tick species present in camel herds in Tunisia (Gharbi et al, ). This confirmed previous findings indicating that ticks showed the highest rickettsial infection rates compared with camels, particularly H. dromedarii from Tunisia (50%) (Demoncheaux et al, ), Palestine (5%–11%) (Ereqat et al, ; Kleinerman et al, ), Egypt (42%) (Abdullah et al, ) and Algeria (8.5%) (Djerbouh et al, ). In this study, tick infestation was considered as a significant risk factor in camel rickettsiosis (6.5%; 95% CI: 0.01–0.112; p = .001).…”

“…Regarding camels, this prevalence is similar to that recorded in Palestine (2%) (Kleinerman et al, ). Contrariwise, this result is significantly lower than those reported earlier in Nigeria (18.8%) (Kamani et al, ) and in Egypt (41%) (Abdullah et al, ).…”

“…Camelids seem to be potential hosts of rickettsial species, particularly in African and Asian arid regions. Molecular prevalence in camels was estimated at 41% in Egypt (Abdullah et al, ) and 18.8% in Nigeria (Kamani, Baneth, Apanaskevich, Mumcuoglu, & Harrus, ). Rickettsia aeschlimannii was identified in camels from Palestine (2%) (Kleinerman, Baneth, Mumcuoglu, Straten, & v., Berlin, D., Apanaskevich, D. A., Abdeen, Z., Nasereddin, A.…”

“…Ticks of Hyalomma genus were considered as potential vectors of Rickettsia spp., especially H. dromedarii (Abdullah et al, ; Al‐Deeb, Bin Muzaffar, Abu‐Zeid, Rizk Enan, & Shahid, ), H. impeltatum , H. excavatum (Ereqat et al, ; Kleinerman et al, ), as well as H. impressum, and H. marginatum rufipes (Djerbouh et al, ).…”

Preliminary Detection of Rickettsiae Using PCR Targeting OmpA Gene Among Dogs and Horses in Cairo, Egypt

“…In Egypt, a few studies were conducted on the diagnoses of Spotted Fever Group rickettsiae (SFG) in ixodid ticks. Two SFG species, Rickettsia africae and Rickettsia aeschlimanni were recorded in Hyalomma spp collected from camels, and R. africae was only detected in the camel host [18][19][20]. Knowledge about rickettsiae in dogs and horses are still lack.…”