RESUMEN
A single morphologic type of Sarcocystis cysts found in two out of 43 examined common coots, Fulica atra, is considered to represent a new species for which the name Sarcocystis atraii n. sp. is proposed and its description is provided. Coots were hunted from the vicinity of Brolos Lake located at KafrElsheikh province, Egypt. The structural morphology of the revealed sarcocysts was described using light and transmission electron microscopy. Sarcocysts were found in the leg and thigh muscles. The cysts were microscopic and measured 165-850 µm in length × 50-85 µm in width. Histologically; the sarcocyst wall was wavy and had minute undulations. Ultrastructurally, it measured 1-3 µm in thickness and possessed many mushroom-like villar protrusions sometimes originating from other mushroom-like villar protrusions that measured approximately 0.5-2 µm in length and up to 2 µm in width, with the presence of electron dense ground substance of 300 nm to 1 µm thick. The bradyzoites were elongated, banana-shaped and measured 7.5-14 × 1.5-2.5 µm, with centrally or terminally located nuclei. The ultrastructural features of the cyst wall belonged to type 24. On the basis of sequencing and phylogenic analyses for 18S rRNA , 28S rRNA genes and ITS-1 region; S. atraii n. sp. is considered a genetically distinct species, being most closely related to avian Sarcocystis spp. whose definitive hosts are predatory mammals.
Asunto(s)
Aves/parasitología , Sarcocystis/clasificación , Sarcocystis/aislamiento & purificación , Sarcocistosis/veterinaria , Animales , Análisis por Conglomerados , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Egipto , Histocitoquímica , Microscopía , Datos de Secuencia Molecular , Músculos/parasitología , Filogenia , ARN Ribosómico 18S/genética , ARN Ribosómico 28S/genética , Sarcocystis/citología , Sarcocystis/genética , Sarcocistosis/parasitología , Análisis de Secuencia de ADNRESUMEN
Sarcocystis species are among the most common and widespread protozoan parasites of mammals and birds. The current study provides the first record of infection with Sarcocystis species in the common moorhens from Brolos Lake, KafrElsheikh province, Egypt. Morphology of the parasite cysts was described using light and transmission electron microscopy. Out of 25 examined birds, sarcocysts were found in neck, thigh, and legs muscles of two birds. The cysts were microscopic and measured 150-650 µm in length×45-185 µm in width. Histologically, the sarcocyst wall appeared striated and characterized by the presence of radial spines. Ultrastructurally, it measured 2-4.5 µm in thickness and had irregularly shaped crowded finger-like villar protrusions that measured 1.5-4 µm in length and up to 0.4-2 µm in width with the presence of dense electron ground substance of 200-750 nm thick. Several septa derived from the ground substance were present and divided the cyst into compartments containing both bradyzoites and metrocytes. The bradyzoites were banana-shaped and measured 6-12 × 1-2 µm with centrally or posteriorly located nuclei. The ultrastructural features of the cyst wall belonged to type 10 cyst wall according the classification of Dubey et al. (1989) and Dubey and Odening (2001).
