Electron microscopic study of in vitro cultures of Hammondia heydorni (Berlin 1996) tachyzoites after passages through dogs, mice, rats, guinea pigs and jirds

Abstract

This study describes the fine structure and reproduction of tachyzoites of Hammondia heydorni (isolate Berlin 1996) after in vitro cultivation of stages isolated from serial passages between dogs and various intermediate hosts such as mice, rats, guinea pigs, jirds, knock-out mice, goats and sheep. The tachyzoites are identical with respect to their ultrastructural features to the corresponding stages of the NC-1-strain of Neospora caninum. This fact conforms with other already published data and underlines our opinion that the recently redescribed N. caninum Dubey et al. 2002 is a synonym of the previously described H. heydorni (Tadros and Laarman 1976) Dubey 1977.

Effects of toltrazuril and ponazuril on the fine structure and multiplication of tachyzoites of the NC-1 strain of Neospora caninum (a synonym of Hammondia heydorni) in cell cultures

“…Neospora caninum is an apicomplexan parasite that is identical with specimens described previously as Hammondia heydorni (Heydorn 1973;Dubey 1977;Schares et al 2001aSchares et al , 2001bMu¨ller et al 2001;Heydorn and Mehlhorn 2002;Mehlhorn and Heydorn 2003). This species is suspected to be involved in abortion and severe neuromuscular disease in fetuses of cattle and dogs.…”

“…The cells were embedded in Araldite (Serva, Heidelberg). Selected areas of the cell cultures were sectioned with a Reichert Ultracut microtome, placed on copper grids and stained with uranyl acetate and lead citrate for transmission electron microscopy as described elsewhere (Mehlhorn and Heydorn 2003).…”

Effects of toltrazuril and ponazuril on Hammondia heydorni (syn. Neospora caninum ) infections in mice

“…Neospora caninum is an apicomplexan parasite that is identical to Hammondia heydorni ( Schares et al 2001a( Schares et al , 2001bHeydorn and Mehlhorn 2002;Mehlhorn and Heydorn 2003). This parasite has often been found in cases of abortion and severe neuromuscular disease in fetal cattle and dogs.…”