Tick-borne diseases comprise a complex epidemiological and ecological network that connects the vectors, pathogens, and a group of host species. The aim of this study was to identify bacteria from the genus Rickettsia associated with ixodid ticks infesting camels and cows in Egypt. Ticks were collected from 6 different localities: Qina, Giza, Qalet El Nakhl, New Valley, El Arish, and Minufia, from July to October 2008. Species were identified using PCR, followed by sequencing. The gltA and rOmpA genes were used for the initial detection of Rickettsia spp. Further characterization of positive samples utilized primers targeting rOmpB, sca4, and intergenic spacers (mppA-purC, dksA-xerC, and rpmE-tRNA(fMet)). Cows were infested with Hyalomma anatolicum excavatum and Boophilus annulatus. Camels were infested with Hyalomma dromedarii, H. impeltatum, and H. marginatum marginatum. Approximately 57.1% of H. dromedarii ticks collected from Qalet El Nakhl were infected with Rickettsia africae, exhibiting 99.1-100% identity to reference strains. Within H. impeltatum, 26.7% and 73.3% of ticks from El Arish were infected with R. africae and R. aeschlimannii, with 98.3-100% and 97.9-100% identity, respectively. Furthermore, 33.3% of H. marginatum marginatum ticks in Qalet El Nakhl were infected with the same two species as H. impeltatum, demonstrating 99.1-100% and 99.3-100% identity, respectively. By comparing percent identities and phylogenetic relationships, R. africae is identified for the first time in Egypt, in addition to R. aeschlimannii, which exhibits 100% identity with the Stavropol strain in GenBank. In conclusion, the obtained data underscore the medical and veterinary importance of tick-borne rickettsioses, which necessitate further investigation by authorities in Egypt. Moreover, additional characterization of these rickettsial isolates should be performed to designate their strains, using a polyphasic strategy combining genotypic and phenotypic tests, to facilitate their deposition in the rickettsial collection of the WHO and/or ATCC.

Aim:Rickettsioses have an epidemiological importance that includes pathogens, vectors, and hosts. The dog tick Rhipicephalus sanguineus and the camel tick Hyalomma dromedarii play important roles as vectors and reservoirs of Rickettsiae. The aim of this study was to determine the prevalence of Rickettsiae in ixodid ticks species infesting dogs and camels in Egypt, in addition to, the morphological and molecular identification of R. sanguineus and H. dromedarii.Materials and Methods:A total of 601 and 104 of ticks’ specimens were collected from dogs and camels, respectively, in Cairo, Giza and Sinai provinces. Hemolymph staining technique and OmpA and gltA genes amplification were performed to estimate the prevalence rate of Rickettsiae in ticks. For morphological identification of tick species, light microscope (LM) and scanning electron microscope (SEM) were used. In addition to the phylogenetic analyses of 18S rDNA, Second internal transcript spacer, 12S rDNA, cytochrome c oxidase subunit-1, and 16S rDNA were performed for molecular identification of two tick species.Results:The prevalence rate of Rickettsiae in ticks was 11.6% using hemolymph staining technique and 6.17% by OmpA and gltA genes amplification. Morphological identification revealed that 100% of dogs were infested by R. sanguineus while 91.9% of camels had been infested by H. dromedarii. The phylogenetic analyses of five DNA markers confirmed morphological identification by LM and SEM. The two tick species sequences analyses proved 96-100% sequences identities when compared with the reference data in Genbank records.Conclusion:The present studies confirm the suitability of mitochondrial DNA markers for reliable identification of ticks at both intra- and inter-species level over the nuclear ones. In addition to, the detection of Rickettsiae in both ticks’ species and establishment of the phylogenetic status of R. sanguineus and H. dromedarii would be useful in understanding the epidemiology of ticks and tick borne rickettsioses in Egypt.

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.

The genus Hyalomma comprises the most ixodid tick species that parasitize camels in Egypt. Although the immature stages of tick species play an important role in distribution of ticks and tick-borne diseases, the identification depends mainly on the adult stage. Therefore, this study tries to identify the specific characteristics of both nymph and larva of Hyalomma rufipes Koch, 1844 using scanning electron microscopy and morphometric analysis in order to differentiate them easily from those of other Hyalomma spp. described before in Egypt. Results showed that the nymph and larva of H. rufipes can be easily identified from those of H. excavatum Koch, 1844, H. dromedarii Koch, 1844 and H. impressum Koch, 1844 but they are strongly close to H. marginatum Koch, 1844. The nymph of H. rufipes can be distinguished from H. marginatum by the number and distribution of dorsal and ventral idiosomal setae and the distribution of sternal setae. All morphological characteristics of H. rufipes larva resemble those of H. marginatum larva. The measurements of nymph and larva structures of H. rufipes are significantly lower than those of H. marginatum.

Five bacterial strains were isolated from the hemocoel of the greater wax moth larvae (Galleria mellonella) infected with the entomopathogenic nematodes: Heterorhabditis bacteriophora HP88, Heterorhabditis indicus RM1 and Heterorhabditis sp (S1), Steinernema abbasi and Steinernema sp. (S II). Strains were identified as Photorhabdus luminescens HRM1, P. luminescens HS1, P. luminescens HP88, Xenorhabdus indica and X. nematophila ATTC19061 using 16S rDNA sequence analysis. To reveal the genetic diversity among these strains, three molecular markers (RAPD, ISSR and SRAP) were employed. RAPD analysis showed 73.8 and 54.5 polymorphism percentages for the Photorhabdus and Xenorhabdus strains, respectively. ISSR analysis resulted in 70.1 and 75.2 polymorphism percentages among the Photorhabdus and Xenorhabdus strains, respectively. The SRAP analysis indicated that 75.6 and 61.2% genetic polymorphism was detected among Photorhabdus and Xenorhabdus strains, respectively. The cluster analysis grouped the three Photorhabdus strains together in one cluster and the two Xenorhabdus strains together in another cluster indicating the phylogenetic relationships among them. The genotype-specific markers detected from the three molecular markers (RAPD, ISSR and SRAP) were sufficient to distinguish between the different bacterial strains tested and can be used in the future IBM program that could be built on the use of these strains.