Interaction between tapeworm infection and heavy metals accumulation in the host

Heavy metals in living organisms occur in trace amounts. While zinc is an essential element wich is indispensable for many physiological processes, cadmium in body acts as atissue toxin, that can cause oxidative stress and contribute to cancer development. Recent studies suggest that some species of tapeworms (Cestoda) and Acantocephala are able to absorb in their tissue higher quantity of heavy metals in comparsion with their hosts. Moreover it was observed that In connection with the increased accumulation of heavy metals in the tissue of tapeworm was decreased amounts of these metals in the organs of the host. The aim of this thesis was to investigate whether the rat tapevorm (Hymenolepis diminuta) causes a decrease in the concentration of Cd and Zn in the organs of rats. A total of 24 Wistar rats (Rattus norvegicus) were divided into 4 groups (n=6). Groups PT and 0P take increased doses of kadmium (3,0 mg/week) and zinc (235,7 mg/week) for six weeks. This increased intake was achieved by adding Arabidopis halleri to feed. After six weeks rats were killed and concentrations in their tissues (bone, muscle, testes, spleen, intestine, liver kidney) were analyzed. Subsequent statistical tests confirmed lower levels of Cd and Zn in some organs of rats infected with tapeworm compared to rats without infection. For example in kidney, liver ant intestine of infected rats was detected 2,9; 2,5 and 1,8 times lower concentrations of cadmium and zinc in comparsion with uninfected rats. Tapeworm absorbed 1695 time higher amount of kadmium compared to the host muscle. The zinc content was lower in all organs (except spleen and testes) of infected rats in comparsion to uninfected. In kidney, liver and intestine of infected rats was 1,2; 1,25 and 1,4 times lower average concentration of zinc in comparsion with uninfected rats. The tape worm absorb higher concentration of zinc compared to all organs of the host

Non-native Nematode Ashworthius sidemi Currently Dominates the Abomasal Parasite Community of Cervid Hosts in the Czech Republic

International audienceAshworthius sidemi is an abomasal nematode typical for Asiatic cervids such as sambar (Rusa unicolor) or sika deer (Cervus nippon). This non-native parasite was introduced into Europe via sika deer in the late 19th and early 20th centuries. The current dynamic spread of this parasite amongst autochthonous wild cervids occurs independently of human activities, and A. sidemi has a negative impact on the health of wild ruminants and may pose a threat to the conservation of endangered wild ungulates and to livestock. This invasive parasite has been previously detected in the Czech Republic, but more accurate information on A. sidemi is required. Only limited information is generally available on the factors influencing the spread of abomasal nematodes in wild ruminants, so more information is necessary for planning effective strategies of parasite control. We therefore conducted a survey on the abomasal nematodes in cervids in both game reserves and hunting grounds across the Czech Republic, taking into account the hosts (species, age, sex) and environmental factors (monthly average temperature). The abomasa of 104 animals belonging to five cervid species originating from various locations of the country were collected. Data on host (species, sex, and age group) and the monthly average temperature in the region were obtained for each animal. The parasitological analyses indicated that 92% of the abomasa were infected by nematodes. Ashworthius sidemi was the most prevalent (72%) and abundant (80% of the total recovered individuals) nematode species and was detected in all cervid species except white-tailed deer. The intensity of A. sidemi was highest in roe deer (Capreolus capreolus) and fallow deer (Dama dama), but A. sidemi abundance did not depend substantially on the host or environmental factors. In contrast, the abundance of nematodes from the subfamily Ostertagiinae was influenced by the host species and temperature. Parasitic load was significantly higher in roe deer and during the warmer periods of the survey. We also detected another non-native nematode species, Spiculopteragia houdemeri. The results of our study suggest that the non-native nematode A. sidemi is now widespread amongst cervid hosts in the Czech Republic, probably due to the high sensitivity of autochthonous cervids to A. sidemi infections as well as adaptation of this parasite to the current climatic conditions of this country

An alien parasite in a changing world – Ashworthius sidemi has lost its traditional seasonal dynamics

A non-native nematode Ashworthius sidemi has emerged in captive fallow deer in Central and Eastern Europe over the last decade. Although this parasite has been spreading in the wild outside it’s native distributional range and colonising local European host species since the middle of the last century, limited information has been published on the seasonality of A. sidemi and its susceptibility to anthelmintics. To address this knowledge gap, we conducted a study to investigate seasonal dynamics of the non-native parasite in the current Central European climate conditions. We collected freshly voided faecal pellets at four-week intervals from February 2018 to February 2020 at a fallow deer reserve with a known history of A. sidemi presence. The faecal pellets obtained were pooled after each site visit (n = 25) and coprocultured to obtain the third stage larvae of trichostrongylid nematodes at monthly intervals. Total genomic DNA was extracted from the recovered larvae. Using real-time multiplex PCR, A. sidemi DNA was detected in 17 out of 25 larval samples (68% prevalence). During the monitoring period, the annual administration of ivermectin based premix (Cermix) took place in January 2018, 2019, and 2020, and additionally a mixture of rafoxanide and mebendazole (Rafendazol) was administered once in spring 2019. The probability of parasite presence was significantly influenced by the time since the drug administration (p = 0.048) and the mean temperature at the location (p = 0.013). Larval samples negative for A. sidemi were always identified shortly after the drug administration. However, rapid pasture contamination by the parasite eggs from two to three months after Cermix administration and within one month after Rafendazol administration suggest only a short-lived efficacy of both administered drugs. The abundance of A. sidemi DNA was positively affected by mean temperature (p = 0.044) and remained relatively stable throughout the monitoring period, with the highest peak in August 2018 and 2019. Pasture contamination with A. sidemi eggs occurred almost all year round, with the exception of the beginning of 2018, 2019, and 2020. These findings indicate adaptation of a non-native parasite to the current climatic conditions of the Czech Republic resulted in negligible seasonal patterns of parasite egg shedding

A revision of the trichostrongylid nematode Cooperia Ransom, 1907, from deer game: recent integrative research confirms the existence of the ancient host-specific species Cooperia ventricosa (Rudolphi, 1809)

The trichostrongylid roundworms of the genus Cooperia, which are important in veterinary medicine, currently comprise 19 valid species that parasitize the small intestine of both free-living and domestic ruminants. Only four Cooperia spp. have been reported in Europe, namely C. oncophora, C. punctata, C. curticei and C. pectinata. In 2018–2022, 25 red deer (Cervus elaphus) and 30 sika deer (Cervus nippon) of both sexes and various ages from several remote locations in the Czech Republic were parasitologically examined. Intestinal nematodes of the genus Cooperia were found only in two northern regions. Using the globally recognized key book on trichostrongylid nematodes, they were preliminarily identified as C. pectinata. However, a molecular analysis of cox2 and ITS rDNA gene sequences revealed that Cooperia sp. parasitizing Czech deer is a separate taxon that is more closely related to C. oncophora than to C. pectinata. A subsequent morphological analysis and literature survey confirmed the independence of deer Cooperia sp., which is similar but not identical to bovid C. pectinata. Previous long-term correct identifications of bovid C. pectinata and misidentifications of deer Cooperia species were caused by a fundamental error in the key book mentioned above. Interestingly, the ancient trichostrongylid nematode Strongylus ventricosus from the type host red deer (Cervus elaphus) shot near Greifswald (Germany) was described by Rudolphi in 1809. Rudolphi's type material (one male and four females) was deposited in the Museum für Naturkunde (Berlin). Later, the ancient species S. ventricosus was taken as a synonym for various Cooperia spp. Our current re-examination of the type male indicated that there is a relatively good agreement with our new material from Czech deer regarding the most important characteristics of S. ventricosus (i.e., the shape and size of the male spicules); however, Rudolphi's type material is in rather poor condition. The suggested resurrection of the deer Cooperia sp. in this study as Cooperia ventricosa (Rudolphi, 1809) requires verification by collecting and analyzing new nematode material from the type locality near Greifswald