Prevalence of Eimeria Species in Camels (Camelus dromedarius) from Egypt and Variability in Structure of Eimeria cameli Oocysts

Abstract

Coccidiosis is a common disease of camels, and camels are important for the economy of Asia and the Arabian Peninsula. Little is known regarding the prevalence of coccidian parasites in camels in Egypt. Fecal samples collected from the rectums of 200 camels at the Cairo slaughterhouse were processed using the sucrose flotation technique. Eimeria species oocysts were found in 38%. Three Eimeria species were identified: Eimeria cameli-like in 31%, Eimeria rajasthani in 18%, and Eimeria dromedarii in 14%. The morphology of E. rajasthani and E. dromedarii oocysts was identical to that in literature. However, there was great variability in size and structure among E. cameli oocysts; oocysts were 70-100 μm long and truncate to ovoid. Four morphotypes (types 1 to 4) were recognized. Types 1 and 2 oocysts had similar truncate ovoid shape and were dark brown, but their shape indices were different. Both types could be easily distinguished from type 3 (elongate ovoid and light brown). All oocysts were enclosed in a transparent outer covering (capsule), although this capsule was barely seen in types 3 and 4. An extension from the capsule situated in front of the micropyle, referred to as polar cap-like structure (PCL), was characteristic for types 1 and 2. The PCL of type 1 resembled the crown, while in type 2 it looked like a small thickening with a smooth top. The PCL was absent in types 3 and 4 oocysts. The latter was found only in a single oocyst. Experimental infections with E. cameli oocysts and molecular studies are needed to determine whether the monotypes described here are different species or strain variations or both.

Keywords: Egypt; Morphology; Prevalence.