Sarcocystis species lethal for domestic pigeons.

A large number of Sarcocystis spp. infect birds as intermediate hosts, but pigeons are rarely affected. We identified a novel Sarcocystis sp. that causes lethal neurologic disease in domestic pigeons in Germany. Experimental infections indicated transmission by northern goshawks, and sequence analyses indicated transnational distribution. Worldwide spread is possible.

Molecular biological comparison of different Besnoitia species and stages from different countries.

Besnoitia besnoiti tissue cysts from a recent outbreak in cattle in Germany were characterized with respect to their internal transcribed spacer regions 1, 2, and 18S rDNA gene sequences. These results were compared with own sequences of an Israelian isolate of B. besnoiti and of Besnoitia jellisoni cystozoites stored for years in liquid nitrogen. Furthermore, material was studied that was obtained from white mice (Balb/C) that had been successfully infected by intraperitoneal infection of fresh cystozoites from the German outbreak. All results were then compared and discussed with respect to databank sequences of other Besnoitia species. Comprehensive phylogenetic studies of B. besnoiti isolates from Germany revealed almost identical sequence alignments when compared to previously sequenced B. besnoiti isolates from Israel and Spain. More importantly, phylogenetic analysis revealed two distant clusters of Besnoitia species: the first one includes Besnoitia akodoni, Besnoitia darlingi, and Besnoitia oryctofelisi, while the second cluster includes B. besnoiti, Besnoitia bennetti, Besnoitia tarandi, and the Besnoitia species of rodents (B. jellisoni). The also B. jellisoni named species of the GenBank (AF 076860) must be another one, since our strain derives directly from Frenkel. These findings give strong hints that B. besnoiti has a cycle between rodents and a predator and that cattle and other are only accidental hosts.

Another African disease in Central Europa: Besnoitiosis of cattle. I. Light and electron microscopical study.

The paper reports the first detection of besnoitiosis of cattle in Germany. Just 2 years after the first appearance of the African Bluetongue disease (BTD) of cattle in Central Europe, another African agent of disease has arrived in Germany. While it was proven that the BTD virus was transmitted (after its first appearance) by endemic midges of the genus Culicoides (C. obsoletus, C. pulicaris), nothing is known, how the infectious stages of Besnoitia besnoiti-a member of the so-called cyst-forming coccidia-found their way to a herd in Southern Germany. The infected animals showed all characteristic clinical symptoms of besnoitiosis such as hyposclerodermia, hyperkeratosis, alopecia, and whitish tissue cysts in subcutaneous tissues as well as in the cornea. These cysts had diameters of up to 3 mm and consisted of a dense outer layer (=secondary cyst wall), which surrounded a host cell, that had been enormously enlarged by an inner parasitophorous vacuole containing thousands of 7-9 x 2 mum sized, banana-shaped cyst merozoites (=cystozoites, bradyzoites).Their fine structure was identical to that of published stages of B. besnoiti. During cyst development, the nucleus of the host cell had been hypertrophied and had apparently undergone several divisions, since many flattened, but very large nuclei were seen in light and electron microscopy. Thus, this study proves the arrival of another serious agent of disease of ruminants in Central Europe-a fact which is especially important, since in this species, there is neither information on the way of transmission from animal to animal nor exists concrete information on an efficacious therapy or on the modalities of its import into Germany.

[Dermacentor reticulatus (Fabricius, 1794)--distribution, biology and vector for Babesia canis in Germany]. / Dermacentor reticulatus (Fabricius, 1794)-- Verbreitung, Biologie und Vektor von Babesia canis in Deutschland.

This work deals with occurrence, distribution as well as biology and vectorial capacity of the ornate dog tick (Dermacentor (D.) reticulatus). Until 30 years ago this tick has only been described in a few natural foci in southern Germany. Its distribution has however expanded in the course of the last years. With the exception of northern Germany it is now covering large areas of Germany. This is particularly the case in the Upper Rhine Valley, Saarland and the Mark Brandenburg. However, it is endemic in many other areas of Germany as well. The transformation of agricultural land into fallow land, an increase in host reservoirs and climatic changes are discussed as main contributors to this change. Little is known about the role of this species as a vector for virus, rickettsia, bacteria and protozoa as well as its medical and veterinary importance. D. reticulatus is a vector for Babesia canis canis. It is reported here about a case of autochthonous babesiosis in a dog from Berlin/Brandenburg.

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

Mice infected with tachyzoites of Neospora caninum (syn.: Hammondia heydorni) must be pretreated with cortisone in order to show disease symptoms. This indicates the status of an opportunistic agent of disease. Toltrazuril was an effective curative agent.

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.

Rhesus monkey kidney cell cultures were used to propagate tachyzoites of the NC-1 strain of Neospora caninum (syn. Hammondia heydorni). The infected cell cultures were incubated for 4-12 h in media containing 0, 1, 10 or 100 microg/ml of either toltrazuril or ponazuril. The effects were studied by light and electron microscopy. Drug dosages of at least 30 microg/ml were needed to eliminate the parasites. Ponazuril was found (with respect to the reduction of the number of parasites) to be less effective at dosages of 30 microg/ml compared to toltrazuril. However, the damage to the tachyzoites being incubated in 30 microg toltrazuril or ponazuril seen by electron microscopy was so significant that it was surely lethal. The initial damage occurred within the apicoplast and the tubular mitochondrion in all cases,thus destroying two of the most important cell organelles.

Neospora caninum is an invalid species name: an evaluation of facts and statements.

An evaluation of both the formal requirements of the International Rules of Zoological Nomenclature and the scientific reasons for the description of new genera and species shows that the name Neospora caninum is a nomen nudum. The only characteristic criteria for discriminating between the previously described species Hammondia heydorni and the proposed new species N. caninum (i.e. the lack of a parasitophorous vacuole) has been shown to be wrong in many publications. Furthermore, absolutely no criteria were presented as to why a new genus (i.e. Neospora) should be established besides the already existing genera Hammondia, Toxoplasma and Isospora. In addition, recent transmission experiments show that an oocyst isolate (from the faeces of dogs) is morphologically indistinguishable from H. heydorni [synonymous with Isospora bigemina - small form, Isospora heydorni (Tadros and Laarman 1976) and H. heydorni (Tadros and Laarman 1976) Dubey 1977] and is almost identical with respect to molecular biological features with the NC-1 strain of N. caninum.

In contrast to dogs, red foxes (Vulpes vulpes) did not shed neospora caninum upon feeding of intermediate host tissues.

To clarify whether red foxes (Vulpes vulpes) can be final hosts of Neospora caninum, foxes and dogs were fed in parallel on tissues of a sheep and a goat experimentally infected with N. caninum. The faeces of at least two of five dogs contained N. caninum oocysts, as determined by bioassay. In the faeces of all six foxes fed in parallel, oocysts were detected that were larger in size (length 12.6 +/- 0.5 microm, width 11.8 +/- 0.4 microm) than the oocysts shed by the dogs. Ribosomal RNA sequences and the results of an immunoblot-based bioassay provided further evidence that these oocysts were different from N. caninum. A titration experiment performed to determine the sensitivity of a bioassay utilising gerbils showed that as few as five sporulated N. caninum oocysts could be detected by this test. This indicates that, in two feeding experiments, less than 3,700 and 200 sporulated N. caninum oocysts, respectively, could have been among the Hammondia sp.-like oocysts collected from fox faeces. These results suggest that the red fox is either an inappropriate final host for N. caninum or not at all a final host for this parasite.