Dr. Murai Éva szerk.: Parasitologia Hungarica 16. (Budapest, 1983)

Mod. 2 7 00 cryomicrotome, stained with hemalaun-eosin and examined with a ZEISS photomicroscope II at a magnification of 1:150. Samples found to be positive for Sarcocystis were washed in cacodylate buffer, pH 7.4, postfixed in 1% OSO4 for 2h, dehydrated in ethanol, then double stained with 1% uranyl in 7 0% ethanol. After final dehydration in ethanol, the material was embedded in Araldit. Ultrathin sections were cut on a REICHERT Ultracut ultramicrotome and examined with a ZEISS EM 9S2 electron microscope. RESULTS During our study 29 female and 21 male red deer were examined for Sarcocystis infection in the regions of Borsod, Pest, Somogy and Zala. Fifteen of 50 animals were found to be infected with Sarcocystis. Only heart muscle samples were Sarcocystis positive; no sample of esophagus muscle was infected. In older animals (3-10 years) the infection rate was 38.7% (Table 1). The infection density of the tissue was low. On histological sections of 0.5-1 cm^ on more then 1-2 cysts could be detected. The cysts measured 44-100 ^um in diameter and 130-420 jam in length. Table 1 Age in years • 1-3 3-10 Animals examined 5 14 31 Animals infected 0 3 (21. 3%) 12 (38. 7%) Legends All electron micrographs represent sections through cysts of Sarcocystis sp. from the heart muscle of Cervus elaphus. Fig. 1 Section through the marginal part of a cyst showing the cyst wall (CW) adjacent to the sarcoplasm (SP) and mitochondria (MIH) of the host cell. Note the merozoites (ME) or cystozoites with prominent micronemes (MN), rhoptries (RH) and conoid (C). Two accumulations of deteriorating material (DM) are present inside the cyst (x 5 800). Fig. 2 Higher magnification of the cyst wall with band-like protrusions (PR) formed by the primary cyst wall, with granular cyst ground substance (GS) underneath. Note the host cell mitochondrion (MIH) bordering the cyst-wall protrusion (x 30 100). Fig. 3 Longitudinal section through a merozoite with conoid (C) micronemes (MN) rhoptries (RH) in the anterior part and a nucleus (N) in the posterior part of the cell. The merozoite is limited by a three membranous pellicle (PE) (x 11 500). Fig. 4 Section through a metrocyte with vacuolated cytoplasm (V) containing a nucleus (N) and mitochondrion (MI). The metrocyte is located immediately underneath the cyst wall (CW) (x 12 000). Abbreviations C CW DM GS ME MI MIH Conoid Cyst wall Deteriorating material Ground substance Merozoite Mitochondrion Host-cell mitochondrion MN Micronemes N Nucleus PE Pellicle PR Protrusions RH Rhoptries SP Sarcoplasm V Vesicle