Haemogregarines infecting reptiles in Egypt 1) Blood and merogenics stages of Haemogregarine sp. infecting the skink Scincus scincus in Egypt

Abstract

In the present study, 25 individual male and females of the skink Scincus scincus were collected and examined for the prevalence of haemogregaarine infection. Peripheral blood smears and thin blood films were prepared and microscopically examined. Eight animals were found to be infected with an infection rate reaching 32%. Parasitaemia was changed from low level to the highest one reaching 25-40%. Intracellular blood stages of different morphological and morphometric characteristics were only parasitize the blood erythrocytes. None of leucocytes were found to be infected. Infected blood cells were completely changed, hypertrophied; their nuclei were displaced and deformed. Single and double parasite individual were found to harbor the same cell. All parasites were enclosed in parasitophorous vacuoles. These vacuoles were sometimes clear, wide and easily observed. Some free extracellular blood stages were rarely observed. Different developmental stages of meronts were observed in liver parenchyma cells which considered as the main site of infection and extends to infect the spleen in heavily infected cases. Two types of meronts were clearly identified, the small form (micromeronts) with small number of nuclei that measured 16.0±0.5 × 10.5±0.7 μm and produce large merozoites (macromerozoites), the large form (macromeronts) with numerous nuclei that measured 25.4±0.6 × 17.8±0.6 μm and produce smaller and more numerous merozoites.