Observations on the histomorphology of sarcosporidian cysts of some East African game animals (Artiodactyla)

Sarcocystis cafferi n. sp. (Protozoa: Apicomplexa) from the African buffalo (Syncerus caffer)

Sarcocystis infections have been reported from the African buffalo ( Syncerus caffer ), but the species have not been named. Here we propose a new name Sarcocystis cafferi from the African buffalo. Histological examination of heart (92), skeletal muscle (36), and tongue (2) sections from 94 buffalos from the Greater Kruger National Park, South Africa, and a review of the literature revealed only 1 species of Sarcocystis in the African buffalo. Macrocysts were up to 12 mm long and 6 mm wide and were located in the neck muscles and overlying connective tissue. They were pale yellow; shaped like a lychee fruit stone or cashew nut; turgid or flaccid and oval to round (not fusiform). By light microscopy (LM) the sarcocyst wall was relatively thin. By scanning electron microscopy (SEM), the sarcocyst wall had a mesh-like structure with irregularly shaped villar protrusions (vp) that were of different sizes and folded over the sarcocyst wall. The entire surfaces of vp were covered with papillomatous structures. By transmission electron microscopy (TEM), the sarcocyst wall was up to 3.6 μm thick and had highly branched villar protrusions that were up to 3 μm long. The villar projections contained filamentous tubular structures, most of which were parallel to the long axis of the projections, but some tubules criss-crossed, especially at the base. Granules were absent from these tubules. Longitudinally cut bradyzoites were 12.1 × 2.7 μm in size, had a long convoluted mitochondrion, and only 2 rhoptries. Phylogenetic analysis of 18S rRNA and cytochrome C oxidase subunit 1 (cox1) gene sequences indicated that this Sarcocystis species is very closely related to, but distinct from, Sarcocystis fusiformis and Sarcocystis hirsuta. Thus, morphological findings by LM, SEM, and TEM together with molecular phylogenetic data (from 18S rRNA and cox1) confirm that the Sarcocystis species in the African buffalo is distinct from S. fusiformis and has therefore been named Sarcocystis cafferi.

Sarcocystis dubeyella n. sp. and Sarcocystis phacochoeri n. sp. (Protozoa: Sarcocystidae) from the warthog (Phacochoerus aethiopicus) in South Africa

Sarcocystis dubeyella n. sp. and S. phacochoeri n. sp. from muscle fibers of the skeletal musculature of two warthogs in South Africa are described by light and and electron microscopy. Sarcocystis dubeyella sarcocysts are macroscopic (up to 12 mm long and 1 mm wide), with a parasite-induced encapsulation of the host muscle fiber in which the plasma membrane of the latter remained unaltered. The sarcocyst wall is characterized by evenly arranged, irregularly semicircular or rectangular villar protrusions (5.0 x 2.8-11.0 microns) with indented margins and no specific content. Sarcocystis phacochoeri formed filiform microcysts (up to 4 mm long and 0.13 mm wide). Its cyst wall is provided with tightly packed, molarlike villar protrusions (1.6-3.3 x 1.7-3.3 microns), with smooth margins, hollow on one side, and with longitudinal condensations of the fine granular matrix at various locations in the interior.

Ultrastructure of Sarcocystis sp. from the muscle of a white-tailed deer (Odocoileus virginianus)

Sarcocystis sp. from the muscle of naturally infected white-tailed deer (Odocoileus virginianus) was examined by transmission electron microscopy. The primary cyst wall forms regularly spaced protrusions filled with electron-lucent ground substance; no fibrils are present in the protrusions. The cysts are divided by septa into compartments containing typical coccidian metrocytes and merozoites. Taxonomy of the protozoon from the white-tailed deer-dog is discussed.