Class Trematoda Research Articles

CHARACTERIZATION OF INTESTINAL ENDOPARASITES FAUNA WITH ZOONOTIC POTENTIAL OF ROAD KILLED WILD MAMMALS IN NORTHERN PARANÁ

Roads and highways are of paramount importance for national trade and transportation. Linked to this, we observe various environmental impacts, including the invasion of wildlife habitat, the roadkill of wild animals, and consequent harm to the fauna in the vicinity of the highways. The aim of the study was to characterize the intestinal parasitic fauna of wild animals killed by roadkill in Northern Paraná. Wild animals killed by roadkill were collected in situ on the main highways in the northern region of Paraná and were sent to the State University of Londrina for autopsy and biological material collection. The parasitological fecal examinations performed included Willis, Faust, and Hoffmann methods. Our results revealed a large quantity of parasites, and even though the research was conducted with a small number of animals, the results may have broader implications. Many of the parasites found have zoonotic potential, such as parasites from the classes Trematoda and Cestoda, subclass Coccidia, family Trichostrongylidae, and genera Ancylostoma spp. and Capillaria spp. It can be concluded that the identification of the intestinal parasitic fauna of wild animals killed by roadkill is a valuable tool for investigating parasites with zoonotic potential. Further studies focusing on this characterization are necessary due to the increasing interaction between humans and wild animals. This is the first report of Octosporella-like oocysts in Nasua nasua in Brazil. Molecular studies are required for confirmation.

Nuclear ribosomal transcription units in Asian Paragonimus species (Paragonimidae: Platyhelminthes): genetic characteristics, polymorphism, and implications for intersuperfamilial phylogeny.

The entire transcribed sequences (from the 5' terminus of 18S to the 3' terminus of 28S rRNA genes) of the ribosomal transcription units (rTU*) of five Asian Paragonimus species were obtained and characterized. The rTU* length was 7661bp for P. heterotremus (LC strain, Vietnam), 7422bp for P. iloktsuenensis (Amami strain, Japan), 6932bp for P. skrjabini miyazakii (OkuST1 strain, Japan), 7422bp for P. ohirai (Kino strain, Japan), and three strains of P. westermani: 8616bp (Megha strain, India), 7292bp (Bogil strain, South Korea), and 7052bp (QT2 strain, Vietnam) without intergenic spacer region (IGS). All seven Asian Paragonimus strains' genetic characteristics were described, including the length of individual genes/regions, repeat polymorphism, base composition, and skewness. To investigate the superfamilial relationships in the Xiphidiata, with a focus on the Troglotrematoidea and its associated superfamilies, we used the PhyML software package to create three comprehensive maximum-likelihood phylogenies. The datasets used were 83 concatenated 28S + 18S, 83 single complete 18S, and 157 single, partial 28S rDNA sequences, respectively, from entire rTUs and/or accessible ribosomal sequences of the same species from the suborders Xiphidiata, Echinostomata, and Haplosplanchnata, with a Schistosoma sequence as an outgroup. Three phylogenetic trees revealed that Echinostomata and Haplosplanchnata are monophyletic, while Xiphidiata is polyphyletic and contains the monophyletic Troglotrematoidea. The concatenated 18S + 28S and single 18S phylogenies revealed well-bootstrap supported seven superfamilies (Troglotrematoidea, Haploporoidea, Gorgoderoidea, Brachycladioidea, Microphalloidea, Plagiorchioidea, and Opecoeloidea) that are monophyletic in the Xiphidiata. The Haploporoidea was a basal superfamily nested close to the Gorgoderoidea and Troglotrematoidea and was not supported as a distinct suborder Haploporata. Six of seven xiphidiatan superfamilies were monophyletic in the partial 28S phylogeny, with the exception of Opecoeloidea, which was separated into two different subclades: Opecoelidae and Stenakridae/Zdzitowieckitrematidae. The monophyletic Haploporoidea/Haploporata was separated from the Gorgoderoidea associates and placed in a marginal group in Xiphidiata. There were two notable clusters in the Paragonimidae: mixed-Paragonimus, which included a fairly compact group of P. heterotremus strains, and P. westermani/siamensis, which was divided into geographical/country strain groups. In conclusion, combined ribosomal rDNA sequences were more effective than single rDNA markers in resolving interfamilial and familial relationships. The ribosomal datasets presented here will be useful for taxonomic reassessment, as well as evolutionary and population genetics research in the Troglotrematoidea and other superfamilies in the Xiphidiata and the class Trematoda.

On the fauna of parasites of the gastrointestinal tract of small ruminants in the mountainous zone of Armenia

The aim of the research is to study the parasitic invasion of small ruminants in the mountainous zone of Armenia during summer and autumn, in this case to determine the invasiveness of parasites of the digestive tract of sheep.The material was feces collected from sheep on pastures in the coastal zone of the Getik River during 2022. The work was carried out at the Scientific Centre of Zoology and Hydroecology, National Academy of Sciences, Republic of Armenia. The material researched also included mollusks and oribatid mites – intermediate hosts of biohelminths.As a result of the study of parasitic invasion of small ruminants in the mountain zone of Armenia, the taxonomic composition of parasites was determined. Helminths found in sheep belong to the classes Trematoda, Nematoda, and Cestoda, protozoa – to the class Protozoa.In the autumn season, representatives of seven genera of parasites of the gastrointestinal tract were found – Moniezia, Dicrocoelium, Fasciola, Nematodirus, Strongylus, Trichuris, Eimeria, while in the summer season, only representatives of five genera were found – Moniezia, Dicrocoelium, Nematodirus, Strongylus, Eimeria.As a result of these studies, it can be concluded that natural and climatic factors of the environment have a significant impact on the structure of the helminth complex of sheep in the mountain region of Armenia.All parasites found can have a detrimental effect on the sheep's body. However, the severity of the invasion in the samples taken is not at the level that could lead to serious diseases in sheep. This suggests that the treatment methods used on farms are at a fairly high level.

Ecological-Faunistic Analysis of Helminthes of Waterbirds of the Aidar-Arnasay System of Lakes in Uzbekistan

For the first time, the faunal complexes of helminths of waterbirds in the Aidar-Arnasay system of lakes in Uzbekistan were studied. The material for this work was collections of parasitic worms of waterbirds obtained during the hunting seasons of 2020-2023. Using parasitological dissection, 326 bird individuals belonging to 31 species and 6 orders (Grebes, Copepods, Flamingiformes, Anseriformes, Craniformes and Charadariformes) were studied. The features of the distribution and ecology of helminths of the studied groups of birds are considered. In total, 79 species of parasites have been registered in the Aidar-Arnasay lake system. Of these, 29 species belong to the class Cestoda, the class Trematoda is represented by 27 species, the class Acanthocephala – by 3 species and the class Nematoda – by 20 species, which are indicated for the study area for the first time. Original data on the structure of the helminth fauna of 6 orders of waterfowl and wading birds are presented. Various routes of transmission of helminths to their hosts, birds, and methods of circulation of the invasion have been elucidated. The life cycles of most species of helminths noted by us involve intermediate (first and second) and reservoir hosts - invertebrate and vertebrate animals. The dietary choices of individual waterbird orders play a significant role in determining the types of parasitic worms that infect them, and are the primary factor in shaping their overall worm population. These processes undeniably take place within a specific timeframe and location, closely regulated by environmental factors.

TheSystematics of the Trematoda.

The platyhelminth class Trematoda comprises two subclasses with largely disparate species diversity, with the small Aspidogastrea with c.80 species and the speciose Digenea with c.18,000 species, which has attracted much effort towards our understanding of evolutionary relationships among suprageneric taxa. This chapter focuses on insights into the classification of the Digenea, that have become apparent from our advanced understanding of both morphological and molecular data. The field of molecular systematics of the Digenea has experienced significant advances over the past 15years. Phylogenetic analyses of sequence data predominantly from the 18S and 28S rRNA genes have incorporated a considerable diversity of taxa, thus increasing the accuracy of phylogenetic inferences at higher taxonomic levels. As a result, the status of long-standing supraspecific taxa has been revised, new higher-level taxa have been defined, and inferences made in association with morphological and life-cycle evidence. A substantial effort has been made towards a classification reflecting a natural system of the Digenea by considering morphological evidence in conjunction with phylogenies inferred from molecular data; this has resulted in considerable congruence. However, limited taxon sampling in the phylogeny of the Digenea still remains relevant, especially in relation to some higher-level taxa, and an outline of these omissions is presented. A framework that has led to robust estimates of phylogeny is outlined, and the application of advanced morphological and molecular approaches in digenean taxonomy and systematics is illustrated using the most comprehensively studied digenean superfamilies.

HELMINTH OF COMMON SNAKE (NATRIX NATRIX L.) OF MORDOVIA

In 2008 it is investigated helminthofauna of the grasssnakeNatrix natrix L. in territory of the Republic of Mordovia (Russia). 15 species of parasitic worms (from which 11 species concern to class Trematoda and 4 - to classNematoda)aremarkedatareptile.From adult stages the greatest extensiveness of an invasion Macrodera longicollis, Astiotrema monticelli, Leptophallus nigrovenosus, Telorchis assula (Trematoda) and Rhabdias fuscovenosus (Nematoda) differed

Biodiversity of helminths in Karakul sheep in the Khorezm Oasis of Uzbekistan

The purpose of the research is to study the helminth fauna and the structure of helminthocenoses of Karakul sheep in the Khorezm Oasis of Uzbekistan.Materials and methods. The material for this study was helminths collected by conventional methods from Karakul sheep from farms of different types in the Khorezm Region. A total of 13 sheep were studied. To identify the dominant helminth infections in sheep, 110 sets of individual organs were examined by the method of partial helminthological dissections. Helminths were collected in slaughterhouses of the Bagat, Kushkupyr, Urgench, Yangiaryk and Shavat Districts of the Khorezm Region. Additionally, the helminths collected from sheep in the Khorezm Region for 2015–2021 were used.Results and discussion. We found that the helminth fauna of Karakul sheep from the Khorezm Oasis was represented by 22 species of the classes Cestoda, Trematoda and Nematoda. Cestodes were represented by 6 species, trematodes by 3 species, and nematodes by 13 species. The faunistic composition of helminths in studied animals was noticeably depleted as compared to other Uzbekistan regions due to natural and ecological conditions of the Khorezm Oasis. The total helminth infection rate in sheep was 100%. The intensity of infection varied depending on the season of the year and the age of sheep and ranged from tens to several thousand specimens. Almost all organs and systems of the animals were found to be ecological niches of the above helminths. Most of helminth species were common to both domesticated and wild ungulates.

Ecological and faunal characteristics of helminths of wetland birds in North-Western Uzbekistan

The article studies some faunistic features of helminths of wetland birds in the ecological crisis zone in North-Western Uzbekistan. Parasites of wetland birds collected in the basin of the lower reaches of the Amu Darya during the hunting seasons of 2018–2022 were used as material for this work. 500 individuals of birds representing 39 species from 24 genera, 13 families and 9 orders were examined using the parasitological dissection method. The article discusses the distribution and ecology of the helminths in the studied groups of birds. A total of 112 helminth species were identified in the region – 28 species belong to the class Cestoda, the class Trematoda is represented by 57 species, Nematoda – 23 and Acanthocephala – 4 species. 92 species of heminths were identified in the study area for the first time. The work provides original data on the structure of the helminth fauna from 9 orders of wetland birds. Various paths of helminth transmission in the circulation of infection were specified. The researchers identified four ways parasites use to enter their definitive host: helminths penetrate the host’s body when the latter eats other organisms, intermediate or reservoir hosts of helminths, which are part of the definitive’s host’s diet; helminths enter the host as mechanical impurity to food or water; they make active efforts to penetrate their host; helminths are transmitted by the intermediate host when the latter forages on the definitive host. Most of intermediate hosts for representatives of the class Cestoda were crustaceans – inhabitants of different types of water bodies; Oligochaeta are also included here as second or reservoir hosts. The development of trematodes occurs with the participation of aquatic molluscs acting as the first intermediate host. Various species of insects, fish, amphibians, reptiles and small mammals were identified as the second hosts. Nematoda use a wider range of intermediate hosts (Oligochaeta, crustaceans, insects – aquatic and terrestrial). Fish and amphibians were registered as the second and reservoir hosts of nematodes. The food chains of individual orders of wetland birds largely determine the composition of helminths parasitising them and are the main factor in the formation of their helminth fauna. These processes undoubtedly occur in time and space under the strict control of environmental factors.

A Survey of Helminths of Dogs in Rural and Urban Areas of Uzbekistan and the Zoonotic Risk to Human Population.

Dogs are very popular pets that can be infected with a wide diversity of endo- and ectoparasites, some of which have zoonotic potential. The aim of the present study was to determine the diversity and prevalence of helminths in rural and urban dogs in Tashkent, Samarkand and Karakalpakstan regions of Uzbekistan. A total of 399 dogs from rural and urban areas were examined by necropsy between November 2016 and March 2022. All helminth species were morphologically identified. A total of 31 species belonging to the classes Trematoda (3), Cestoda (9), Nematoda (18) and Acanthocephala (1) were identified in 378 dogs (94.7%). Twenty-one species are indicated for the helminth fauna of urban dogs and 31 species for rural dog populations. From the 31 species of helminths identified 18 species are zoonotic and four of them (Echinicoccus granulosus, Dipylidium cani-num, Toxocara canis, Dirofilaria repens) have a significant epidemiological importance. The study showed that the prevalence and diversity of helminths in dogs in rural areas of Uzbekistan is higher than in urban dogs.

Gastrointestinal Helminths of the Mediterranean house Gecko: Hemidactylus turcicus (Linnaeus, 1758) in Tocra city, northeast Libya

A total of one hundred and two of H. turcicus (Forty-two male, and sixty female) were collected from three locations in Tocra city, during the period from March to September 2019. Fifty-eight (56.9%) of collected and sacrificed lizards were found infected with at least one species of helminths. Four parasitic species were detected in the gastrointestinal of these geckos, three species belong to phylum Nematoda and one species belong to phylum platyhelminth, class Trematoda. These species are Phragodon mamillatus, Paraphragodon spp., Oxyroid spp., and undefined species of trematode. Most of the infected lizards (93%) showed a single infection and only four individuals have mixed parasites. The result showed no significant difference in the prevalence of the parasites between male and female lizards (P-value = 0.962). Positive correlations were found between Snout-Vent Length (SVL), body weight, and the presence of parasites. There was no significant correlation between, body weight, SVL, and intensity of parasites

Identification of new polymorphic positions in rDNA sequences of the "intermediate" Fasciola forms.

Fascioliasis is a foodborne zoonotic disease generally caused by the parasitic flukes Fasciola gigantica and Fasciola hepatica in class Trematoda. An "intermediate" Fasciola forms between F. gigantica and F. hepatica has been shown to exist. However, the relationships among F. gigantica, F. hepatica, and "intermediate" Fasciola forms remain unclear. In this study, we found five new polymorphic positions in 18S and 28S rDNAs sequences of "intermediate" Fasciola forms. According to the high-throughput sequencing results, all known 16 polymorphic positions of "intermediate" Fasciola forms show a clear and consistent tendency for F. gigantica or F. hepatica, and the percentages of the most frequently occurring bases were different in specimens. In the three ITS sequence fragments, hybrid-type base combinations of the polymorphic positions were detected, and the percentages of the most frequent base combinations were different in specimens too. In addition, interestingly, the newly detected ITS-802 position was not a traditional polymorphic position in "intermediate" Fasciola forms, and the bases in ITS-802 position are not same as the allele bases of F. gigantica or F. hepatica. Our results will be helpful to investigations into the molecular taxonomy, population genetics, and ecology of F. gigantica, F. hepatica, and "intermediate" Fasciola forms.

Structural Organization of Vitelline Cells of Trematode with Undifferentiated Body of Azygia Lucii (Muller, 1776)

It is known that the class Trematoda includes exclusively parasitic forms of flatworms. In this regard, they have formed a variety of morphological and functional adaptations to a parasitic lifestyle. One of them is the colossal fecundity, which provides the possibility of rapid and wide settlement and detection of hosts. Therefore, the study of the sexual reproduction of helminths is the central problem of parasitology. The study of the functional morphology of the reproductive system of trematodes in general and its parts, is of particular interest in solving such an important problem in theoretical and practical terms as the directed regulation of the fecundity of end parasites. The present article provides information on the functional morphology of the vitelline cells of the Azygia lucii trematode, describing in detail the micromorphology and ultrastructure of the vitelline cells and the development stages of vitelline cells in the course of vitellogenesis. As a result, the knowledge gained on the peculiarities of the structure and maturation of Azygia lucii vitelline s will significantly supplement the knowledge about the peculiarities of the structure of the female reproductive system of Strigeidae trematodes and the fecundity of end parasites.

Структурно-видовая и возрастная оценка гельминтов класса Trematoda Rudolphi, 1808 у овец карачаевской грубошерстной породы в регионе Центрального Кавказа

The species composition of helminths of the class Trematoda Rudolphi, 1808 was studied in sheep of the Karachay rough-haired breed in Kabardino-Balkaria, which is represented by 7 types of helminths: Fasciola hepatica, Dicrocoelium lanceatum, Paramphistomum cervi, P. ichikawai, Liorchis scotiae, Calicophorum calicophorum, Eurytrema pancreaticum. These species met with an extensive invasion, respectively 16,67 %, 40,00 %, 20,00 %, 16,67 %, 13,33 %, 20,00 % and 6.67 % and the intensity of the invasion from 8 to 312 copies / head.

Effects of Parasitism on the Production and Productivity of caged Oreochromis niloticus in Winam Gulf of L. Victoria

The general objective of this study was to assess the effects of parasitism on the production and productivity of caged Oreochromis niloticus in Winam Gulf of L. Victoria. With the need to increase food production through fish products amid overfishing and pollution stress in the lake, cage farming is seen to have the potential to bridge the fish supply and demand gap continues to widen. Cage culture is a new technology in the offing that needs to be explored to justify its potential. Fish parasites are always a threat in an enclosed culture system and because of this, it is necessary to assess their effects on fish condition factors before recommendation. It is because of this reason that a total of 480 caged Oreochromis niloticus were purchased and examined for parasites using the recommended procedures for parasitological analysis. The class Trematoda which included seven taxa were found to be the most common and prevalent parasites in cages of the Winam Gulf. This was attributed to the presence of piscivorous birds which are definitive hosts seen more often around the culture systems and also overstocking observed and reported during the study period which increases the spread and transmission of parasites from one fish to another. Despite the prevalence, infestation did not affect the fish condition factor in all the study areas as the majority of infected fish recorded between good and excellent body condition factors. This was due to low mean intensities recorded and a shorter period of exposure to parasitic infestation as most farmers were barely 3 years into the system. In conclusion, for the government to explore the blue economy and achieve the Vision 2030 and SDGs on food security and poverty reduction by 2030, efforts to promote commercial cage culture enterprises in the Winam Gulf must be bolstered, provided that cages are located in deep waters with low concentrations in specific areas and low stocking densities to avoid compromising the environment.

Simultaneous genotyping of snails and infecting trematode parasites using high-throughput amplicon sequencing.

Several methodological issues currently hamper the study of entire trematode communities within populations of their intermediate snail hosts. Here we develop a new workflow using high-throughput amplicon sequencing to simultaneously genotype snail hosts and their infecting trematode parasites. We designed primers to amplify four snail and five trematode markers in a single multiplex PCR. While also applicable to other genera, we focused on medically and economically important snail genera within the superorder Hygrophila and targeted a broad taxonomic range of parasites within the class Trematoda. We tested the workflow using 417 Biomphalaria glabrata specimens experimentally infected with Schistosoma rodhaini, two strains of Schistosoma mansoni and combinations thereof. We evaluated the reliability of infection diagnostics, the robustness of the workflow, its specificity related to host and parasite identification, and the sensitivity to detect co-infections, immature infections and changes of parasite biomass during the infection process. Finally, we investigated its applicability in wild-caught snails of other genera naturally infected with a diverse range of trematodes. After stringent quality control the workflow allows the identification of snails to species level, and of trematodes to taxonomic levels ranging from family to strain. It is sensitive to detect immature infections and changes in parasite biomass described in previous experimental studies. Co-infections were successfully identified, opening the possibility to examine parasite-parasite interactions such as interspecific competition. Together, these results demonstrate that our workflow provides a powerful tool to analyse the processes shaping trematode communities within natural snail populations.

Identification and evolution of nuclear receptors in Platyhelminths.

Since the first complete set of Platyhelminth nuclear receptors (NRs) from Schistosoma mansoni were identified a decade ago, more flatworm genome data is available to identify their NR complement and to analyze the evolutionary relationship of Platyhelminth NRs. NRs are important transcriptional modulators that regulate development, differentiation and reproduction of animals. In this study, NRs are identified in genome databases of thirty-three species including in all Platyhelminth classes (Rhabditophora, Monogenea, Cestoda and Trematoda). Phylogenetic analysis shows that NRs in Platyhelminths follow two different evolutionary lineages: 1) NRs in a free-living freshwater flatworm (Schmidtea mediterranea) and all parasitic flatworms share the same evolutionary lineage with extensive gene loss. 2) NRs in a free-living intertidal zone flatworm (Macrostomum lignano) follow a different evolutionary lineage with a feature of multiple gene duplication and gene divergence. The DNA binding domain (DBD) is the most conserved region in NRs which contains two C4-type zinc finger motifs. A novel zinc finger motif is identified in parasitic flatworm NRs: the second zinc finger of parasitic Platyhelminth HR96b possesses a CHC2 motif which is not found in NRs of all other animals studied to date. In this study, novel NRs (members of NR subfamily 3 and 6) are identified in flatworms, this result demonstrates that members of all six classical NR subfamilies are present in the Platyhelminth phylum. NR gene duplication, loss and divergence in Platyhelminths are analyzed along with the evolutionary relationship of Platyhelminth NRs.

A systematic review of flukes (Trematoda) of domestic goose (Anser anser dom.)

Trematodes are one of the most numerous and widespread groups of parasitic invertebrates among helminths, characterized by a complex life cycle. As the final host, digenetic flukes parasitize vertebrates, including domestic waterfowl. Infection of hosts with parasitic digenetic worms causes huge economic damage to poultry. But trematode fauna of domestic geese are presented mainly only for individual regions. Despite the fact that there is already a systematic review of tapeworms and acanthocephala of domestic birds – geese and ducks, there are, unfortunately, no review articles on the taxonomy of digenetic flukes for geese (Anser anser dom.). Taking into account the relevance of the topic, based on our own and extensive literature data, we set the task to determine the general species composition of digenetic flukes (Trematoda), parasitizing in domestic geese which have been recorded in the world until 2020. Each Trematoda species is provided with the following data: scientific name, authority and year, first, second intermediate, auxiliary and final hosts, site in the host body, collecting localities and geographic distribution, and literature sources. Currently it is established that there are 149 species of helminths parasitising domestic geese. The taxonomic composition of the class Trematoda registered in domestic geese consists of 2 classes, 14 families, 30 genera and 65 species. Of all the species of trematodes parasitizing in domestic geese, 44 species have been recorded in Europe, 26 species in Asia, 6 species in North America, 1 species in South America, 1 species in Africa and 2 species in Oceania. Three species are registered in domestic geese (Echinoparyphium recurvatum, Echinostoma revolutum, Prosthogonimus ovatus) are cosmopolitan parasites. The biggest species diversity is characterized by the families Echinostomatidae (17 species) and Notocotylidae (12 species). There are 11 species of digenetic flukes recorded in domestic geese Cyclocoelum mutabile, Echinostoma grande, E. paraulum, E. revolutum, E. robustum, Hypoderaeum conoideum, Paryphostomum novum, P. pentalobum, Catatropis verrucosa, Notocotylus attenuatus, N. parviovatus) on the territory of Azerbaijan. Four of them (Echinostoma revolutum, Hypoderaeum conoideum, Paryphostomum novum, Notocotylus attenuatus) were also noted in the course of our helminthological studies. The trematode Cyclocoelum mutabile was recorded in domestic ducks only in Azerbaijan. Most species of trematodes were found in the north-eastern part (total 9 species) and southern part (total 5 species) of Azerbaijan. This is due to the widespread distribution of molluscs – intermediate hosts of digenetic flukes, in these regions. Eighteen species of digenetic flukes parasitize both birds and mammals (Rodentia, Carnivora, Lagomorpha, Artiodactyla). And eleven species of trematodes are of medical importance, registered in humans.

Helminthofauna of mouse rodents and helminthe parasitism Hymenolepis horrida, Linstow, 1901

In forest and forest-steppe biocenoses, mouse-like rodents are one of the leading groups in terms of number and species diversity. Performing the functions of consults of the first and second orders in the food chain, rodents play a role in the circulation of helminths as intermediate and main hosts, besides, with their participation, especially dangerous natural focal invasions are maintained. In modern practice, the existing focal infestations also actively circulate in natural biocenoses, and the vast territory of Yakutia is no exception. Permafrost and a particularly low temperature regime in the region could contribute to the death of the invasion, but many types of helminths, their eggs and larvae maintain their active state in the harsh climatic conditions of Yakutia, sometimes have a pronounced tendency to spread and form extensive natural foci. Of particular interest is the study of the helminthofauna of mouse-like rodents characteristic of this region. The material for this article was the study of the helminth fauna. As a result of the study of complex parasitological fees for 2018-2021. on the territory of the Central Part of the Republic of Sakha (Yakutia), 1,373 individuals belonging to nine species of mouse-like rodents were studied. The authors processed and analyzed the original materials and the data obtained show that the 30 helminth species found belong to 5 genera and to four classes Trematoda Rudolphi, 1808, Cestoda Rudolphi, 1900, Nematoda Rudolphi, 1808 and Archiacanthocephala, Meyer, 1931.

Zoonotic Endoparasites in Dogs from the Bosnian-Podrinje Canton, Bosnia and Herzegovina

Abstract More than 30 dog parasite species have been identified in Bosnia and Herzegovina so far, and half of these are zoonotic. The aim of the study was to investigate the occurrence of parasitic infections in dogs from Bosnian-podrinje canton with a focus on zoonotic parasites. The study included 212 dogs (107 owned and 105 stray). One or more of the twenty parasite species were found in 82.55% of tested samples. Dicrocoelium dendriticum (Class Trematoda) was found in 0.94% of dogs. Dipylidium caninum and Mesocestoides lineatus (Class Cestoda) were found in 7.55% and 0.94% of dogs, respectively. Taenia spp. and Echinococcus spp. (Family Taeniidae) were found in 0.47% and 0.94% of samples, respectively. In the family of Nematoda, the following parasite species were identified with corresponding percent among tested dogs: Toxocara canis (25.94%), Toxascaris leonine (8.96%), Strongyloides stercoralis (0.47%), Ancylostoma caninum (3.77%), Uncinaria stenocephala (52.36%), Trichuris vulpis (22.17%), Eucoleus aerophilus (1.42%), Dirofilaria immitis (1.89%) and Dirofilaria repens (1.42%). In the kingdom of Protozoa, the following parasite species were identified with corresponding percent among tested dogs: Cystoisospora canis (8.49%), C. ohioensis (2.36%), Cryptosporidium spp. (4.72%), Sarcocystis spp. (0.47%), Babesia spp. (5.19%), and Giardia duodenalis (15.57%). Leishmania infantum was not identified in tested samples. The results showed a high level of parasitic infestation in the dog population in the Bosnian-Podrinje canton, with a high occurrence of zoonotic parasites. Significant differences were found between owned and stray dogs for all classes of detected parasites with exception of the class Trematoda, disregarding specific parasite species.

Immunopathological Response, Histological Changes, Parasitic Burden, and Egg Output in Sheep Naturally Infected by Dicrocoelium dendriticum.

Simple SummaryDicrocoelium dendriticum, commonly known as the lancet liver fluke, is a liver parasite that affects ruminants and occasionally other species, including humans. The aim of this study was to investigate the histological modification and the phenotype of inflammatory cells in the livers of sheep naturally infected with D.dendriticum and the correlation of these variables with the parasitic burden, egg output, and gross appearance of the liver. We studied twenty-four sheep selected on the basis of positive D. dendriticum fecal egg counts. Gross and histological modifications of the liver and the number of adult D. dendriticum worms were examined. Macroscopically, the livers were swollen with thickened bile ducts, cholangitis, and fibrosis. Histologically, we observed leucocyte infiltration, bile duct hyperplasia, and fibrosis. Lesions were present in different degrees of severity and were scored. A significant positive association was observed between the number of adult worms recovered from the liver, egg per gram, macroscopic lesions, fibrosis, and bile duct hyperplasia. A significant negative association was observed among these variables and the degree of leukocyte infiltration. The immunohistochemical examination showed a CD3+ predominant cell population in all assessed animals. These findings allow us to better understand the complex mechanism of the host–parasite interaction, in relation to the egg output and parasitic burden in dicrocoeliosis.The aim of this study was to investigate the correlation between infection by Dicrocoelium dendriticum (class Trematoda) and the animal host response in terms of macroscopic lesions, the immunopathological response, and histological changes in the livers of naturally infected sheep. Twenty-four sheep were selected on the basis of positive D. dendriticum fecal egg counts (FECs). Gross and histological injuries were scored. A positive significant association was observed between the number of adult worms recovered from the liver, FEC, macroscopic lesions, fibrosis, and bile duct hyperplasia. A significant negative association was observed among these variables and the degree of leukocyte infiltration. In addition, immunophenotyping of the inflammatory cells was carried out using primary antibodies against T cell epitopes (CD3+, CD4+, and CD8+), B cell epitopes (CD79α), and the ionized calcium-binding adapter molecule 1 (IBA-1) antigen. Independently of the severity of the D. dendriticum infection, the predominant cell population was CD3-positive and associated with lesser numbers of CD79α- and Iba-I-positive cells. An increase in Iba-1-positive cells was observed in the livers of animals with a high worm burden. Our results provide a reference basis to better understand the local immune response in sheep naturally infected by D. dendriticum in relation to the FEC and parasitic burden.