Coccidiosis in chickens is one of the major problems of poultry industry that is caused by protozoan parasites of genus Eimeria. Cecal contents and cecal mucosal scraping samples were collected from naturally infected native broiler chicken flock aging 25 days. The post mortem examination showed hemorrhagic mucosa with bloody caecal core in two caeca.
Eimeria oocysts were isolated by single oocyst technique. The obtained sporulated oocysts were identified according to morphological features, and the calculated average oocyst shape index of randomly 50 oocysts (1.22 μm), average length (25.2 μm) with SD (±2.24 μm), and average width (20.6 μm) with SD (±1.6μm) as E. tenella. Species-specific polymerase chain reaction (PCR) test targeting the internal transcribed spacer-1 (ITS-1) sequences of the genomic rDNA using primer pairs (E. tenella ET, E. maxima Ema and Emu and E. nexatrix EN) was performed for isolated Eimeria species. The results of species-specific PCR assays confirmed the presence of E. tenella as it has the characteristic in all of the tested samples bp
of 278 but there wasn't band with other previous mentioned primer pairs. Histopathological evidence showed leakage of blood, oedema and necrosis of caecal mucosa.Eimeria tenella developmental stages in caecum were alsodetected histopathologically.