On a Haemogregarine sp. [protozoa, apicomplexa, adeleina] naturally infecting the viper Bitis arientans in Saudi Arabia with reference to the host-parasite relationship

The study described the developmental stages of a haemogregarine species in the blood and tissues of the viper Bitis arientans. Two out of 9 [22.2%] snakes from the south western region of Saudi Arabia, and recorded for the first time in such locality. The erythrocytic parasites were differentiated into three forms: the youngest form [trophozoite] measuring 7.34 +/- 0.16 x 3.38 +/- 0.07 micro m; the intermediate form [developing gametocyte] measuring 13.36 +/- 0.20 x 5.11 +/- 0.11 micro m and the largest form [mature gametocyte] measuring 18.69 +/- 0.32 x 4.32 +/- 0.16 micro m. None of the leucocytes seemed to be parasitized. Also, two types of meronts were detected in lung endothelial cells of infected vipers. Small meronts [micromeronts] measured 21.86 +/- 0.28 x 16.13 +/- 0.25 micro m and yielded about 12 merozoites. The large meronts [macromeronts] measured 38.09 +/- 0.33 x 21.52 +/- 0.32 micro m and yielded 28-42 merozoites. Random distribution of nuclei was observed in early meronts of both sizes, meanwhile peripheral arrangement of nuclei characterizing the subsequent developing events of meronts [ectomerogony]. Histopatho-logical studies showed that the infected erythrocytes were hypertrophied, mechanically stretched and their cytoplasm was faintly stained due to dehaemoglobinization. The host cell nucleus was elongated and laterally displaced. Trabeculae of the infected lung exhibited marked thickening and alveoli were collapsed in various degrees. Haemorrhagic foci and spongy structures were detected in some infected lung tissues. Formation of fibrous tissues around the meronts was seen in some foci

Pathological and ultrastructural studies on Anisakis simplex rudolphi-1809 infecting Carangoides Bajad with special reference to intestinal maturation in puppies

Thirty five [70%] of 51 Carangoides bajad were naturally infected with Anisakis simplex during the period from September 2007 to January 2008. The fish were collected from eastern south coast of the Red Sea at Hurgada. The morphological and ultrastructures of Anisakis larvae and adults, and the induced lesions in the fish [intermediate host], five puppies [final host] were orally given infected fish. The body of the larvae is gradually tapering towards the anterior part. It is covered by striated ornamentation longitudinally and horizontally, except the anterior region which is smooth. The morphological and ultrastrutural examinations of the anterior body end of larvae showed a prominent boring tooth, 3 pairs of lips inconspicuous and an excretory ventral pore between the rudimentary subventral lips. The anal end showed a distinct mucron and a slit-shaped anus. The pathological studies revealed encapsulated larvae with concentrical fibrous connective tissue infiltrated, with macrophages and lymphocytes on the surface of liver, spleen and peritoneum of the infected fish. The macrophages aggregated together to form the denser part of the capsule, and invaded the adjacent parenchymal tissue. The hepatocytes, under the affected capsule were necrotic and invaded by melanomacrophages