title: Ultrastructure characteristics of Besnoitia darlingitachyzoites Brumpt, 1913 (Protozoa: Sarcocystidae) of the Michigan strain MIBD1.
abstract: Tachyzoites of Besnoitia darlingi Brumpt, 1913 were redescribed based on new materials isolated from Virginia opossums (Didelphis virginiana, Kerr) from Michigan, U.S.A. Tachyzoites of the MIBD1 strain were propagated in bovine turbinate cell culture for more than two years. A comparison with previously described tachyzoites of the B. darlingi OP1 strain from Mississippi, USA revealed some morphological differences despite the remarkable genetic homogeneity between the two B. darlingi strains. MIBD1 tachyzoites were distinguished from OP1 tachyzoites by having more rhoptries, and fewer and haphazardly distributed micronemes at the conoidal end. This morphological heterogeneity between tachyzoites of the two strains suggests the role of geographical isolation in the Michigan strain. New morphological features of B. darlingi tachyzoites were described.
authors.affiliation: Division of Veterinary Medicine, The School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Leicestershire, LE12 5RD, United Kingdom.
authors.forename: Hny M
authors.initials: HM
authors.lastname: Elsheikha
authors.forename: Samar N
authors.initials: SN
authors.lastname: El-Beshbishi
authors.forename: Linda S
authors.initials: LS
authors.lastname: Mansfield
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D003048:Coccidiosis / Q000469:parasitology / Q000662:veterinary*; D008824:Michigan; D046529:Microscopy, Electron, Transmission; D009893:Opossums / Q000469:parasitology*; D021745:Sarcocystidae / Q000235:genetics / Q000648:ultrastructure*