GENUS SARCOCYSTSIS

GENUS SARCOCYSTSIS

<p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><b>INTRODUCTION AND IMPORTANCE:</b></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> All </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>Sarcocystis</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> species have a obligatory heteroxenous life cycle. Cats are important as definitive hosts for at least 11 named species (Table 5) and are the intermediate host for one species. </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>Sarcocystis</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> (</span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>Sarco</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> = muscle, </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>cystis</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> = cyst) was first observed in 1843 by F. Miescher in a house mouse (Dubey BOOK). The muscles of the mouse contained "milky white threads" which came to be known as Miescher's tubules. Latter a species was found in the pig and named </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>Synchytrium</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>miescherianum</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> by Kühn in 1865 and changed to </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>Sarcocystis</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>miescheriana</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> by Labbé in 1899. Therefore the correct type species is </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>Sarcocystis</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>miescheriana</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> (Kühn, 1865) Labbé 1899. It was not until the early 1970's that the two-host life cycle was described (Fayer, 1972; Rommel and Heydorn, 1972; Rommel et al., 1972).</span></span></span></p> &nbsp; <div align="RIGHT"> <table border="1" width="712" cellspacing="2" cellpadding="3"><colgroup> <col width="229" /> <col width="463" /> </colgroup> <tbody> <tr> <td colspan="2" valign="TOP" width="701" height="20"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><b>Table 5. Names and intermediate hosts of </b></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i><b>Sarcocystsis</b></i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><b> species transmitted by cats.</b></span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="CENTER"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><b>Species of </b></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i><b>Sarcocystis</b></i></span></span></p> </td> <td width="463"> <p align="CENTER"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i><b>Intermediate host</b></i></span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>cuniculi</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">European rabbit (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Oryctolagus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>cuniculus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>cymruensis</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Norway rat (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Rattus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>norvegicus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>fusiformis</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Water buffalo (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Bubalus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>bubalis</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>gigantea </i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">(syn. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>ovifelis</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Sheep (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Ovis</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>aries</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>hirsuta </i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">(syn. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>bovifelis</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Cow (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Bos</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>taurus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>leporum</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Cottontail rabbit (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Sylvilagus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>floridanus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">, </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Sylvilagus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>nuttalli</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">, </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Sylvilagus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>pallistris</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>medusiformis</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Sheep (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Ovis</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>aries</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>moulei</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"> (syn. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>caprifelis</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Goat (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Capra</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>hircus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>muris</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">House mouse (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Mus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>musculus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="22"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>odoi</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">White-tailed deer (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Odocoileus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>virginianus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> <tr valign="TOP"> <td width="229" height="21"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>S</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">. </span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>porcifelis</i></span></span></p> </td> <td width="463"> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">Pig (</span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>Sus</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><i>scrofa</i></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;">)</span></span></p> </td> </tr> </tbody> </table> </div> &nbsp; &nbsp; <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i><b>SARCOCYSTIS</b></i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><b> SPECIES LIFE CYCLE: </b></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;">The </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>Sarcocystis</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> life cycle is obligatorily a two-host cycle. The intermediate hosts becomes infected by ingestion of sporocysts from the environment. The sporozoites excyst from the sporocysts in the intestinal tract. The sporozoites leave the intestinal tract and undergo first-generation merogony in endothelial cells of arteries usually in mesenteric lymph nodes (Dubey et al., 1989). A second generation of merogony occurs in capillaries or small arteries in many tissues throughout the body. The meronts are usually most numerous in glomeruli of the kidneys. The merozoites from the last generation are released in to the circulation and can occasionally be found intracellularly in unidentified mononuclear cells (Dubey et al., BooK). Limited multiplication may occur at this stage of infection. Eventually these merozoites will penetrate cells and develop into the sarcocyst stage that contains bradyzoites. The first- and second-generation meronts develop directly in the host cell cytoplasm, whereas the bradyzoites develop within a parasitophorous vacuole.</span></span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> The developing sarcocyst contains a stage called a metrocyte that divides by endodyogeny to produce the bradyzoites. A mature sarcocyst can contain thousands of bradyzoites and be grossly visible. The presence of grossly visible sarcocysts of </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>S</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;">. </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>gigantea</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> in sheep and </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>S</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;">. </span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"><i>hirsuta</i></span></span></span><span style="color: #000000;"><span style="font-family: 'Times New Roman', serif;"><span style="font-size: medium;"> in cattle is a cause for condemnation of the carcass (Dubey, Leek, Fayer, 1986; Dubey et al., 1990). </span></span></span></p>