Epidemiological study on factors influencing the occurrence of helminth eggs in horses in Germany based on sent-in diagnostic samples

Gastrointestinal nematodes are ubiquitous parasites of grazing equines with Parascaris spp., and strongyles being the most relevant ones regarding the prevalence and potential disease severity. Despite their importance, epidemiological data regarding the presence and egg-shedding intensities of these parasites are scarce. Data from 1067 horse samples collected on German horse farms initially to compare diagnostic methods were used for epidemiological analyses. Due to its higher sensitivity, presence/absence data were based on a combined sedimentation/flotation technique while faecal egg counts were based on Mini-FLOTAC. For strongyles, 46.5% of the samples were positive and the median egg-shedding intensity was 40 (range 5–2590). In multivariate analyses, prevalence and egg-shedding intensity were significantly influenced by season, age group and sample type. The drug used for the last treatment and the number of foals on the yard only affected prevalence while the number of horses on the yard and sex were only significant for egg-shedding intensity. For Parascaris spp., a prevalence of 4.6% and a median egg-shedding intensity of 0 (range 5–905) were observed. In multivariate analyses, the age group, the time since the last anthelmintic treatment, presence and number of foals had significant effects on ascarid prevalence whereas egg-shedding intensity was significantly influenced by age group and season only. Parascaris occurred only on yards with foals, but with an increasing number of foals, Parascaris egg-shedding intensity decreased. Prevalence and egg-shedding intensity were influenced by different but partially overlapping variables for Parascaris and strongyles

In memoriam: Theodor Hiepe (1929–2022)—great German scholar of parasitology

Theodor Hiepe (1929-2022) was an outstanding researcher, a world-renowned scientist, a dedicated teacher and a great mentor. During his scientific career, which spanned over 60 years, he made major contributions to many different fields of parasitology. With the passing of Dr. h.c. mult. Theodor Hiepe in September 2022 the scientific community suffered a great loss

In memoriam: Theodor Hiepe (1929–2022)—great German scholar of parasitology

Theodor Hiepe (1929-2022) was an outstanding researcher, a world-renowned scientist, a dedicated teacher and a great mentor. During his scientific career, which spanned over 60 years, he made major contributions to many different fields of parasitology. With the passing of Dr. h.c. mult. Theodor Hiepe in September 2022 the scientific community suffered a great loss.Peer Reviewe

In silico analysis of the cyclophilin repertoire of apicomplexan parasites

<p>Abstract</p> <p>Background</p> <p>Cyclophilins (Cyps) are peptidyl <it>cis/trans </it>isomerases implicated in diverse processes such as protein folding, signal transduction, and RNA processing. They are also candidate drug targets, in particular for the immunosuppressant cyclosporine A. In addition, cyclosporine is known to exhibit anti-parasitic effects on a wide range of organisms including several apicomplexa. In order to obtain new non-immunosuppressive drugs targeting apicomplexan cyclophilins, a profound knowledge of the cyclophilin repertoire of this phylum would be necessary.</p> <p>Results</p> <p>BLAST and maximum likelihood analyses identified 16 different cyclophilin subfamilies within the genomes of <it>Cryptosporidium hominis</it>, <it>Toxoplasma gondii</it>, <it>Plasmodium falciparum</it>, <it>Theileria annulata</it>, <it>Theileria parva</it>, and <it>Babesia bovis</it>. In addition to good statistical support from the phylogenetic analysis, these subfamilies are also confirmed by comparison of cyclophilin domain architecture. Within an individual genome, the number of different Cyp genes that could be deduced varies between 7–9 for Cryptosporidia and 14 for <it>T. gondii</it>. Many of the putative apicomplexan cyclophilins are predicted to be nuclear proteins, most of them presumably involved in RNA processing.</p> <p>Conclusion</p> <p>The genomes of apicomplexa harbor a cyclophilin repertoire that is at least as complex as that of most fungi. The identification of Cyp subfamilies that are specific for lower eukaryotes, apicomplexa, or even the genus Plasmodium is of particular interest since these subfamilies are not present in host cells and might therefore represent attractive drug targets.</p

Immunization Trials with Recombinant Major Sperm Protein of the Bovine Lungworm Dictyocaulus viviparus

The lungworm Dictyocaulus viviparus is one of the most economically important bovine parasites in temperate climate regions. Following infection, D. viviparus induces a temporary protective immunity, and a vaccine based on attenuated, infective larvae is commercially available. However, due to several disadvantages of the live vaccine, the development of a recombinant subunit vaccine is highly desirable. Therefore, the major sperm protein (MSP), which is essential for the parasite’s reproduction, was tested as a recombinantly Escherichia coli-expressed glutathione-S-transferase (GST)-fused vaccine antigen in immunization trials with two different adjuvants, Quil A and Al(OH)3. Calves (N = 4 per group) were immunized on study day (SD) 0, 21 and 42 and given a challenge infection on SD 63–65. The two control groups received only the respective adjuvant. Based on geometric means (GM), a 53.64% reduction in larvae per female worm was observed in the rMSP Quil A group vs. its control group (arithmetic means (AM): 54.43%), but this difference was not statistically significant. In the rMSP Al(OH)3 group, the mean number of larvae per female worm was even higher than in the respective control group (GM: 9.24%, AM: 14.14%). Furthermore, male and female worm burdens and the absolute number of larvae did not differ significantly, while the Al(OH)3 control group harbored significantly longer worms than the vaccinated group. Vaccinated animals showed a rise in rMSP-specific antibodies, particularly IgG and its subclass IgG1, and the native protein was detected by immunoblots. Although rMSP alone did not lead to significantly reduced worm fecundity, it might still prove useful as part of a multi-component vaccine

Targeted Selective Treatment (TST) bei Rindern zur Reduzierung der Resistenzbildung bei Endoparasiten

Infektionen mit Endorparasiten, insbesondere mit Magen-Darm-Strogyliden (MDS), sind oft ein limitierender Faktor in der Entwicklung und Produktivität von erststömmrigen Rindern. Diese Infektionen haben somit große wirtschaftliche Bedeutung. Die bisher weitverbreitet durchgeführte strategische Entwurmung (planmäßiger Einsatz von Medikamenten) ganzer Herden sollte aus verschiedenen Gründen angepasst werden

Untersuchung zum Vorkommen von Anthelminthikaresistenzen in norddeutschen Rinderbeständen

Anthelmintic resistance has become a serious problem worldwide especially for small ruminants but it is also rising for cattle. The sustainability to maintain the efficacy of anthelmintics is an important objective. Furthermore, reduction of anthelmintic use is desired to assure safe and high quality food. Therefore targeted selective treatment (TST) systems should be developed. Through TST the use of anthelmintics can be reduced and selection pressure on sensible endoparasite isolates decreases. The current project aims at 1st the investigation of the current efficacy of macrocyclic lac-tone anthelmintics in first season grazing cattle in Northern Germany and 2nd to com-paratively investigate different approaches to TST such as body weight, body condition-ing scores (BCS) and egg output (EPG)

Chronic Wasting Due to Liver and Rumen Flukes in Sheep

Grazing sheep and goats are constantly exposed to helminth infections in many parts of the world, including several trematode species that causes a range of clinical diseases. The clinical picture of flukes is dependent upon the organs in which they develop and the tissues they damage within the respective organs. Accordingly, infections with the common liver fluke Fasciola hepatica, which, as juvenile worm migrates through the liver parenchyma for several weeks, may be associated with hepatic disorders such as impairment of carbohydrate, protein and fat metabolism, followed by chronic wasting. In contrast, the lancet fluke Dicrocoelium dendriticum, which does not exhibit tissue migration and thus does not lead to major tissue damage and bleeding, also does not lead to significant clinical symptoms. Rumen flukes such as Cotylophoron daubneyi cause catarrhal inflammation during their migration through the intestinal and abomasal epithelium during its juvenile stages. Depending on the infection intensity this may result in a range of clinical symptoms including diarrhoea, inappetence or emaciation. In this review, we aim to provide an update on the current knowledge on flukes particularly concerning the clinical relevance of the most important fluke species in sheep

The in vitro assay profile of macrocyclic lactone resistance in three species of sheep trichostrongyloids

Anthelmintic resistance has emerged as an important problem in animal industries. Understanding resistance mechanisms, especially against macrocyclic lactones (MLs), is the first step in developing better diagnostic tools. Effects of several MLs including ivermectins and milbemycins were tested using two well established in vitro assays: the larval development assay (LDA) and the larval migration inhibition assay (LMIA). These were performed on free-living stages of susceptible and ML-resistant isolates of three trichostrongyloid nematode species of sheep. In general, dose response curves shifted to the right in the resistant isolates. Data showed that resistance was present to ivermectin and its two components suggesting that both components contribute to action and resistance. There were no consistent patterns of potency and resistance of the tested substances for the different isolates in the LDA except that moxidectin (MOX) tended to have lower resistance ratios than ivermectin (IVM). MOX was the most potent inhibitor in the LMIA in susceptible Haemonchus contortus while being less potent in Trichostrongylus colubriformis and particularly in Ostertagia circumcincta. MOX showed high resistance ratios in the LMIA in all three species. Based on these results, resistance to MOX has unique characteristics and the LMIA may perform better in detecting resistance to MOX in these parasite species

Entwicklung eines Serum- und Milch-ELISAs zum Nachweis der Infektion mit Magen-Darm-Strongyliden bei Ziegen

Grazing goats are naturally infected with gastrointestinal nematodes which are an important cause of diseases and economic losses. Targeted selective treatment (TST) is a possibility to avoid spreading of anthelmintic resistances and to reduce the use of anthelmintics. The aim of this study is the development of an goat-milk ELISA for the detection of infection with T. circumcincta in order to provide a monitoring tool for herd infection levels. Therefore a group of kids were artificially infected, blood and faecal samples were taken over a period of 10 weeks. Additional a herd of milk goats,kept on pasture at the experimental farm were used to obtain milk, blood and faecal samples regularly