Molecular Detection of Spotted Fever Group Rickettsiae Associated with Ixodid Ticks in Egypt Sobhy Abdel-Shafy, 1 Nesreen A.T. Allam, 1 Oleg Mediannikov, 2 Philippe Parola, 2 and Didier Raoult 2 Abstract 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 com- paring 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 neces- sitate 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. Key Words: gltA—Intergenic spacers—Ixodid ticks—rOmpA—rOmpB—Phylogenetic analysis—Rickettsia—sca4 (gene D). Introduction I n Egypt, the genera Hyalomma, Boophilus, and Rhipi- cephalus comprise the most important ixodid ticks in- festing animals, specifically Hyalomma anatolicum excavatum, H. dromedarii, H. impeltatum, H. marginatum marginatum, Boo- philus annulatus, and Rhipicephalus sanguineus (Abdel-Shafy 1996,2000). The cattle tick, B. annulatus, is considered to be the most important economic pest infesting cows. H. anatolicum excavatum is a parasite of monogastric species (donkeys, horses, dogs, swine, and humans), as well as of large and small ruminants (cattle, camels, sheep, and goats). H. mar- ginatum marginatum is a parasite of domestic animals only. Although H. dromedarii prefers camels, it also infests cattle, sheep, goats, and horses. In addition, H. impeltatum is usually found on all large domestic animals, especially camels and cows (Hoogstraal 1956; Hoogstraal and Kaiser 1958; El- Kammah et al. 2001; Estrada-Pena et al. 2004). The genus Rickettsia contains 25 officially-validated spe- cies and several as yet uncharacterized strains, 16 of which are recognized human pathogens, and another 2 are sus- pected to cause rickettsioses (Fourneir and Raoult 2009; Weinert et al. 2009). Worldwide, these zoonoses exhibit characteristic clinical features, including fever, headache, and occasional eschar formation at the site of the tick bite (Parola and Raoult 2001; Parola et al. 2005). Despite common ecological features and few phenotypic criteria, the classifi- cation and identification of Rickettsia have been based on 1 Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Center, Dokki, Giza, Egypt. 2 Unite ´ des Rickettsies, Faculte ´ de Me ´decine, Universite ´ de la Me ´diterrane ´e, Marseille, France. VECTOR-BORNE AND ZOONOTIC DISEASES Volume 12, Number 5, 2012 ª Mary Ann Liebert, Inc. DOI: 10.1089/vbz.2010.0241 346