Ultrastructure ofSarcocystis bertramisarcocysts from a naturally infected donkey (Equus asinus) from Egypt

Abstract

SummaryThere is considerable confusion concerning Sarcocystis species in equids. Little is known of Sarcocystis infections in donkeys (Equus asinus). Here we describe the structure of Sarcocystis bertrami from the donkey by light and transmission electron microscopy (LM, TEM). Nineteen sarcocysts from the tongue of a donkey from Egypt were studied both by LM and TEM. By LM, all sarcocysts had variably shaped and sized projections on the cyst walls, giving it a thin walled to thick walled appearance, depending on individual cyst and plane of section. By TEM, sarcocysts walls had villar protrusions (vp) of type 11. The sarcocyst wall had conical to slender vp, up to 6 μm long and 1μm wide; the vp were folded over the cyst wall. The total thickness of the sarcocyst wall with ground substance layer (gs) was 1-3 μm. The vp had microtubules that originated deeper in the gs and continued up to the tip. The apical part of the vp had electron dense granules. The microtubules (mt) were configured into three types: a tuft of electron dense mt extending the entire length of the vp with a tuft of medium electron dense mt appearing in parallel, and fine mt present only in the villar tips. The gs was mainly smooth with few indistinct granules. The gs was mainly smooth with few indistinct granules. All sarcocysts were mature and contained metrocytes and bradyzoites. Bradyzoites were approximately 11-15 x 2-3 μm in size with typical organelles.

Morphological and molecular characteristics of Sarcocystis sp. in donkeys from China

“…is a common parasitic protozoan with a worldwide distribution found in a variety of mammals and birds, especially in domesticated food animals. Sarcocysts have been diagnosed in donkeys from the former USSR (Gadaev 1978), Austria (Hinaidy and Loupal 1982), Germany (Matuschka 1983), Morocco (Kirmse 1986), Egypt (Hilali and Nasser 1987;Dubey et al 2016), China (Hu et al 2001), and Italy (Passantino et al 2019). In the present study, the prevalence of sarcocysts in the investigated Chinese donkeys was 37.5% (12/32), and it has been reported to be higher than 22.0% (9/41) in Moroccan donkeys (Kirmse 1986) and 28.6% (40/140) in Italian donkeys (Passantino et al 2019), but lower than 40% (8/20) in the former USSR (Gadaev 1978), 90.0% (18/20) in Egyptian donkeys (Hilali and Nasser 1987) and 92.3% (24/26) in Chinese donkeys surveyed by our group 20 years ago (Hu et al 2001).…”

“…Currently, PCR assays and sequencing procedures are considered much more practical, accurate, and reliable for the delineation and identi cation of Sarcocystis species than traditional methods based on morphological characteristics (Gjerde 2013). Therefore, a critical comparison of the molecular characteristics of Sarcocystis species in donkeys and horses should be performed to help reach a nal conclusion (Dubey et al 2016).…”

“…Subsequently, on the basis of crossinfection between horses and donkeys and the morphological similarity of the sarcocysts found in the two hosts, S. asinus was questioned, and the species of Sarcocystis infecting the two hosts came to be regarded as the same species (Levine and Tadros 1980;Odening et al 1995;Odening 1998). Thus, the name S. bertrami is currently used for the sarcocysts diagnosed in the muscles of donkeys by most authors (Dubey et al 2016;Passantino et al 2019).…”

Brazilian Horses from Bahia State Are Highly Infected with Sarcocystis bertrami

“…Species names of Sarcocystis spp. found in meat from equids have been debated in several studies [ 15 , 16 , 17 , 18 , 19 ]. Sarcocystis bertrami and Sarcocystis fayeri have been described in muscle tissues from donkeys, mules and horses [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ].…”