title: Sarcocystis rommeli, n. sp. (Apicomplexa: Sarcocystidae) from Cattle (Bos taurus) and its Differentiation from Sarcocystis hominis.
abstract: Cattle (Bos taurus) are intermediate hosts for three named species of Sarcocystis, S. cruzi, S. hirsuta, and S. hominis. Recently, a fourth species was identified and named S. sinensis. However, S. sinensis originally named a species of Sarcocystis in water buffalo (Bubalus bubalis) in China. Based on unverifiable evidence, it was suggested that the same parasite infects cattle. In addition, S. sinensis was recently declared as nomen nudum because its naming violated the rules of International Code of Zoological Nomenclature. Thus, the fourth species using cattle as an intermediate host does not have a valid name. Here, we propose a new name, Sarcocystis rommeli for the S. sinensis-like parasite from cattle in Argentina, and differentiate it ultrastructurally from S. hominis sarcocysts from experimentally infected cattle. Sarcocystis rommeli sarcocysts were microscopic with a 5-μm-thick wall with slender villar protrusions (Vp); the Vp were up to 5 μm long, up to 0.5 μm wide, and of uneven thickness, often bent at an angle. The ground substance layer (Gs) was up to 0.8 μm thick and smooth. Vesicular structures were seen at the base of the Vp. The bradyzoites were 10-12 μm long. Sarcocystis hominis sarcocysts had Vp that were often upright, up to 7.5 μm long, and up to 1.8 μm wide; the Gs was up to 2 μm thick and without vesicles. Its sarcocyst wall was up to 5.6 μm thick, the vp were bent at an angle, up to 5.8 μm long, the Gs was up to 2 μm thick, but without vesicles seen in S. rommeli. Beef containing sarcocysts of S. rommeli was not orally infectious for two human volunteers and a red fox (Vulpes vulpes). The Sarcocystis described here is molecularly different from S. cruzi, S. hirsuta, and S. hominis based on 18S rRNA and cox1 gene sequences.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, Maryland, 20705-2350, USA.
authors.forename: Jitender P
authors.initials: JP
authors.lastname: Dubey
authors.affiliation: Laboratorio de Inmunoparasitología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118, 1900, La Plata, Argentina.|Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina.
authors.forename: Gastón
authors.initials: G
authors.lastname: Moré
authors.affiliation: Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
authors.forename: Erna
authors.initials: E
authors.lastname: van Wilpe
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, Maryland, 20705-2350, USA.
authors.forename: Rafael
authors.initials: R
authors.lastname: Calero-Bernal
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, Maryland, 20705-2350, USA.
authors.forename: Shiv K
authors.initials: SK
authors.lastname: Verma
authors.affiliation: Institut für Epidemiologie, Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald-Insel Riems, Germany.
authors.forename: Gereon
authors.initials: G
authors.lastname: Schares
mesh_terms: D000818:Animals; D001118:Argentina / Q000453:epidemiology; D002020:Buffaloes / Q000469:parasitology; D002417:Cattle; D002681:China / Q000453:epidemiology; D005589:Foxes / Q000469:parasitology; D006801:Humans; D046529:Microscopy, Electron, Transmission; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D000069466:Red Meat / Q000469:parasitology; D012522:Sarcocystis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure; D012523:Sarcocystosis / Q000469:parasitology; D009626:Terminology as Topic
chemical_list: D012337:RNA, Ribosomal, 18S
keywords: Definitive host; Intermediate host; Molecular; Ultrastructure