Applied parasitology最新文献

The aim of the study was to investigate the induction of autoantibodies in rabbits after the inoculation with Trypanosoma equiperdum. Eight female rabbits were inoculated s.c. with 5 x 10(6) parasites of Trypanosoma equiperdum. Four of these animals were treated with Diminazen (Berenil) at a dosage of 28 mg per rabbit by intramuscular injection 35 days p. i. Two additional non-infected rabbits served as negative controls. 9 days p.i. all infected animals possessed serum antibodies against Typanosoma equiperdum. Titers peaked to 1:2048, measured between 14 and 30 days p.i. and were persistent until the end of examinations. In parallel, there was an increase of anti-dsDNA and anti-collagen autoantibodies, but not of autoantibodies against recombinant U1RNP and La antigens. In comparison to patients with systemic lupus erythematosus, the anti-DNA binding of rabbit's sera was reduced more strongly in presence of increasing salt concentrations. In addition, the sera of inoculated rabbits recognized several unknown bands of a cell extract in immunoblotting. The parallel increase of antibodies against Trypanosoma, control foreign antigens, DNA and collagen suggests a polyclonal stimulation of the immune system. It was concluded that this rabbit model seems to be sufficient to investigate the mechanisms which are able to induce autoimmune phenomena.

A mating was made between two populations of Eimeria tenella possessing the complementary traits of normal development (virulence) + resistance to the anticoccidial drug arprinocid or precocious development (attenuation) + drug-sensitivity. A small number of "recombinant" oocysts was recovered. The inheritance of markers from both parents into 22 cloned lines derived from the recombinant oocysts was confirmed by analyses of restriction fragment length polymorphisms of four repetitive DNA sequences.

A rhoptry-specific monoclonal antibody (mab) A4C6 was obtained by fusion of X63-Ag 8.653 plasmacytoma cells with splenocytes of BALB/c mice. Mab A4C6 reacted with three protein bands at about 94, 66 and 45 kDa under non-reducing conditions. Gel electrophoresis under reducing conditions separated these protein complexes into several protein fragments ranging between 20 and 200 kDa. Antigens recognised by mab A4C6 were concentrated in the rhoptry sacs located in the apical region of sporozoites as shown by immunoelectron microscopy. During parasite-host cell interaction and development in PCKC culture, mab A4C6 located rhoptry antigens in the parasitophorous vacuole space between intracellular sporozoites and the vacuole membrane.

Epidemiological investigations were carried out in a focus of opisthorchiidosis in Brandenburg state of Germany. 9 out of 23 cats harboured adult flukes in their livers. Beside Opisthorchis felineus, Metorchis bilis was found in 4 cats. Muscle samples of 227 cyprinid fish belonging to 6 species (Rutilus rutilus, Scardinius erythrophthalmus, Alburnus alburnus, Abramis brama, A. ballerus, Blicca bjoerkna) were examined for trematode metacercariae. 12 different types of cysts were found. O. felineus was present in all fish species. R. rutilus and A. alburnus showed a prevalence of Opisthorchis of more than 70%. Two out of 166 Bithynia leachi were positive for trematode developmental stages. Due to their young age the rediae could not be specified.

In view of the considerable public health significance of Echinococcus multilocularis, the causative agent of the highly lethal human alveolar echinococcosis, there is an urgent need for reliable and simple techniques for the diagnosis of the infection in populations of final hosts (foxes, dogs, cats) and also in individual dogs and cats. The standard technique presently used is parsitological examination of the small intestine at necropsy. This reliable technique requires high expenditure and special safety precautions. An alternative approach is coproantigen detection. Recently, in our laboratory an ELISA was evaluated using rabbit and chicken polyclonal antibodies against E. multilocularis antigens (affinity purified coproantigens and somatic adult worm antigens). The specificity of this test (evaluated in 20 foxes and 661 dogs with helmintic infections other than E. multilocularis) was very high (95%-99.5%). Average sensitivity in 35 foxes infected with E. multilocularis was 80%, but reached 93% in foxes with individual worm burdens over 55. A Polymerase Chain Reaction (PCR) was used for detecting DNA of E. multilocular is in faecal samples of foxes after the parasite eggs had been isolated by a sieving procedure. In a total of 55 foxes specificity was 100% and sensitivity 94%. For field application the coproantigen ELISA has the potential of replacing parasite detection at necropsy, and PCR is a valuable method for confirmation of positive coproantigen results and for diagnosis in individual animals. Detection of circulating anti-Em2 antibodies by ELISA may be useful for primary screening of fox populations but antibody prevalence rates do not correlate with prevalence rates of the intestinal infection with E. multilocularis.

The genetic diversity among Sarcocystis gigantea isolates derived from individual cysts within a given infected animal at two abattoirs in Australia and one abattoir in Germany was studied using Restriction Fragment Length Polymorphism (RFLP) analysis of the intergenic transcribed spacer region 1 (ITS 1) of the ribosomal RNA gene operon. S. gigantea isolates were obtained from infected sheep from Blayney (New South Wales), Katanning (Western Australia), and Detmold (North-Rhine Westfalia, Germany) in order to assess the level of diversity among isolates from different geographic locations. Polymerase chain reaction amplification and RFLP analysis of the ITSI region with the restriction enzymes HaeIII, NlaIII, and Sau3AI found no genetic variation among the isolates within one animal or among animals in the same or different locations. To our knowledge, such a field study has not yet been performed on a species in the genus Sarcocystis.

Quantitative faecal and post-mortem examinations of 16 ponies, 1 to 2 1/2 years of age, originating from 3 farms in northern Germany were performed in February 1995 to determine the prevalence and intensity of gastrointestinal parasites in these animals. A total of 33 species of metazoan parasites was recovered: three tapeworm species (Anoplocephala perfoliata, A. magna, Paranoplocephala mamillana), Strongylus vulgaris, S. edentatus, small strongyles (including four Triodontophorus spp., Craterostomum acuticaudatum and 19 cyathostome species), Oxyuris equi, Parascaris equorum, Habronema majus and Gasterophilus intestinalis larvae. Triodontophorus minor and Cylicocyclus triramosus were reported for the first time in Germany.

In vitro incubation of Haemonchus contortus (RUD., 1803) and Trichuris globulosa (v. LINSTOW, 1901) were proformed for 10-12 h in Tyrode's solution and 10 and 50 micrograms/ml concentrations each of albendazole (ABZ), fenbendazole (FBZ), thiophenate (TP), dl-tetramisole and oxyclozanide (TO), dl-tetramisole HCI (TMS) and levamisole HCI (LMS) to study morphological and histochemical alterations. The major structural changes observed after treatment with all the drugs were vacuolation in the intestine of H. contortus except with TP treatment and disruption of the epithelium in T. globulosa except with TMS treatment. The other major alteration in T. globulosa was the loss of muscle striations after TP, TO, TMS and LMS treatments. All the six anthelmintics reduced the quantity of neutral mucopolysaccharides in the intestine of H. contortus and T. globulosa except with TMS and LMS treatments in the latter. Acidic mucopolysaccharides detected in the microvilli of the intestine of H. contortus were lost after TO and ABZ treatments. The loss of lipids from the intestine was evident after TO, ABZ, FBZ and TP treatments in H. contortus and by all the drugs in T. globulosa. LMS treatment caused accumulation of very large lipid droplets in the intestine of H. contortus.

Groups of four deer each were experimentally infected with larvae of Dictyocaulus (D.) eckerti (from fallow deer) or D. viviparus (from cattle) or D. filaria (from sheep), groups of four cattle each with D. viviparus or D. eckerti and groups of 4 lambs each with D. filaria or D. eckerti. The animals were daily examined coprologically following the 16th day post infectionem. The animals were slaughtered at different times and the lungs were dissected. With the exception of the infection of the sheep with D. eckerti from fallow deer, the mutual infections of the different hosts with the lungworm species became patent. Lungworms could be isolated. Fallow deer proved to be more susceptible to an infection with D. viviparus than cattle to an infection with D. eckerti. The large lungworms which naturally infest fallow deer and cattle, D. eckerti and D. viviparus respectively, can be distinguished according to the morphology of their mouth capsules, especially in the structure of the buccal ring. These features were also present after infection of the heterologous hosts.