Sarcocystis cymruensis: discovery in Western Hemisphere in the Brown rat (Rattus norvegicus) from Grenada, West Indies: redescription, molecular characterization, and transmission to IFN-γ gene knockout mice via sporocysts from experimentally infected domestic cat (Felis catus)
Rodents are intermediate hosts for many species of Sarcocystis. Little is known of Sarcocystis cymruensis that uses the Brown rat (Rattus norvegicus) as intermediate hosts and the domestic cat (Felis catus) as experimental definitive host. Here, we identified and described Sarcocystis cymruensis in naturally infected R. norvegicus from Grenada, West Indies. Rats (n = 167) were trapped in various locations in two parishes (St. George and St. David). Microscopic, thin (< 1 μm) walled, slender sarcocysts were found in 11 of 156 (7.0%) rats skeletal muscles by squash examination. A laboratory-raised cat fed naturally infected rat tissues excreted sporocysts that were infectious for interferon gamma gene knockout (KO) mice, but not to Swiss Webster outbred albino mice. All inoculated mice remained asymptomatic, and microscopic S. cymruensis-like sarcocysts were found in the muscles of KO mice euthanized on day 70, 116, and 189 post inoculation (p.i.). Sarcocysts from infected KO mice were infective for cats at day 116 but not at 70 days p.i. By transmission electron microscopy, the sarcocyst wall was “type 1a.” Detailed morphological description of the cyst wall, metrocytes, and bradyzoites is given for the first time. Additionally, molecular data on S. cymruensis are presented also for the first time. Molecular characterization of sarcocysts 18S rDNA and 28S rDNA, ITS-1, and cox1 loci showed the highest similarity with S. rodentifelis and S. muris. In conclusion, the present study described the natural infection of S. cymruensis in Brown rat for the first time in a Caribbean country and provided its molecular characteristics.
KeywordsSarcocystis cymruensis Rattus norvegicus Grenada Ultrastructure Phylogeny
This research was supported in part by an appointment to the Agricultural Research Service (ARS) Research Participation Program administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664.
Compliance with ethical standards
All opinions expressed in this paper are the author’s and do not necessarily reflect the policies and views of USDA, ARS, DOE, or ORAU/ORISE.
- Al-Kappany YM, Abu-Elwafa SA, Hilali M, Rosenthal BM, Dunams DB, Dubey JP (2013) Experimental transmission of Sarcocystis muris (Apicomplexa: Sarcocystidae) sporocysts from a naturally infected cat (Felis catus) to immunocompetent and immunocompromised mice. J Parasitol 99(6):997–1001. https://doi.org/10.1645/13-274.1 CrossRefPubMedGoogle Scholar
- Dubey JP (2010) Toxoplasmosis of animals and humans, 2nd edn. CRC Press, Boca Raton, Florida, pp 1–313Google Scholar
- Dubey JP, Calero-Bernal R, Rosenthal BM, Speer CA, Fayer R (2016) Sarcocystosis of animals and humans, 2nd edn. CRC Press, Boca Raton, Florida, pp 1–481Google Scholar
- Grikieniené J, Arnastauskiené T, Kutkiené L (1993) On some disregarded ways of sarcosporidians circulation and remarks about systematics of the genus Sarcocystis Lankester, 1882 with the description of the new species from rodents. Ekologija 1:16–24 (In Russian)Google Scholar
- Hu JJ, Liao JY, Meng Y, Guo YM, Chen XW, Zuo YX (2011) Identification of Sarcocystis cymruensis in wild Rattus flavipectus and Rattus norvegicus from People’s Republic of China and its transmission to rats and cats. J Parasitol 97(3):421–424. https://doi.org/10.1645/GE-2633.1 CrossRefPubMedGoogle Scholar
- Ruiz A, Frenkel JK (1976) Recognition of cyclic transmission of Sarcocystis muris by cats. J Infect Dis 133:409–418Google Scholar
- Trupkiewicz JG, Calero-Bernal R, Verma SK, Mowery J, Davison S, Habecker P, Georoff TA, Ialeggio DM, Dubey JP (2016) Acute, fatal Sarcocystis calchasi-associated hepatitis in Roller pigeons (Columbia livia f. dom.) at Philadelphia Zoo. Vet Parasitol 216:52–58. https://doi.org/10.1016/j.vetpar.2015.11.008 CrossRefPubMedGoogle Scholar
- Verma SK, Lindsay DS, Rosenthal BM, Dubey JP (2016) Ancient, globally distributed lineage of Sarcocystis from sporocysts of the eastern rat snake (Pantherophis alleghaniensis) and its relation to neurological sequalae in intermediate hosts. Parasitol Res 115(7):2697–2704. https://doi.org/10.1007/s00436-016-5086-2 CrossRefPubMedGoogle Scholar
- Verma SK, Lindsay DS, Mowery JD, Rosenthal BM, Dubey JP (2017b) Sarcocystis pantherophisi n. sp., from eastern rat snakes (Pantherophis alleghaniensis) as definitive hosts and interferon gamma gene knockout mice as experimental intermediate hosts. J Parasitol 103(5):547–554. https://doi.org/10.1645/17-2 CrossRefPubMedGoogle Scholar
- Verma SK, Von Dohlen AR, Mowery JD, Scott D, Rosenthal BM, Dubey JP, Lindsay DS (2017c) Sarcocystis jamaicensis, n. sp. from red-tailed hawks (Buteo jamaicensis) definitive host and IFN-γ gene knockout mice as experimental intermediate host. J Parasitol 103(5):555–564. https://doi.org/10.1645/17-10 CrossRefPubMedGoogle Scholar