Trematode Fasciola Hepatica Research Articles

Molecular characterization of Fasciola hepatica obtained from cattle and horse in Central Chile

Liver fluke infection, caused by the trematode Fasciola hepatica, is a parasitic zoonotic disease affecting various mammals, including humans, and has significant implications for public, animal, and ecosystem health. This study provides the first genetic characterization of F. hepatica in Chile, focusing on the complete mitochondrial gene cox1. Samples were collected from two different host species: cattle and horses. Our findings revealed that 70 % of detected haplotypes were found in either cattle or horses, which coincides with their geographical origin. Interestingly, the use of full-length sequences resulted in the identification of 80 % unique sequences, whereas this reduced to 45 % when analyzing the traditionally used short sequences. This underestimation of genetic diversity suggests that broader sequencing efforts might be essential for a more accurate understanding of F. hepatica genetic landscape. This research underscores the importance of understanding the genetic variability in parasites to improve strategies for disease control and treatment.

Endoparasites of Red Deer (Cervus elaphus L.) and Roe Deer (Capreolus capreolus L.) in Serbian Hunting Grounds.

In this study, parasitological examinations were conducted from 2019 to 2023. Fecal samples were collected from 289 wild ruminants (158 red deer and 131 roe deer) from hunting grounds in Vojvodina, which belong to the public company Vojvodinašume. Using qualitative and quantitative coprological diagnostic methods, the presence of protozoa (coccidia and Buxtonella sulcata), nematodes (gastrointestinal strongyles, Trichuris spp., Capillaria spp., Dictyocaulus spp., and Muellerius spp.), cestodes (Moniezia spp.), and trematodes (Fasciola hepatica, Fascioloides magna, Paramphistomum spp., and Dicrocoelium dendriticum) in the form of single and mixed infections were confirmed. Coproculture was used to identify the infective larvae of gastrointestinal strongyles. The total prevalence of endoparasitic infections in hunting ground 1 was 89.77% in red deer and 92.85% in roe deer, while in hunting ground 2, it was 72.97% in red deer and 85.96% in roe deer. Knowledge of the prevalence and assessment of the intensity of parasitic infections in wild ruminants is necessary for designing health protection programs in hunting grounds and planning control strategies, which are significant for this branch of hunting and public health.

Analysis of the causes of sheep endoparasites in farms of the Luga district of the Leningrad region

This article reflects current data on the assessment of the epizootic situation for the main endoparasitoses of small cattle in two peasant (farm) farms of the Luga district of the Leningrad region with similar animal conditions. The level of extensive invasion (EI) of sheep by pathogens of parasitic diseases was established, and the age and seasonal dynamics of the spread were studied. The level of infection of livestock with strongylates of the gastrointestinal tract with an EI of 87-97%, protostrongylidoses of the genus Mullerius (M. capillaris) with EI – 53%, tapeworms of the genus Moniezia (M. expansa) – 69%, trematodes Fasciola hepatica with EI – 24-28% and eimeria with EI – 96-98%. The analysis of the causes of diseases in the territories of the studied farms was carried out, and the main mechanisms of transmission of pathogens to susceptible animals were considered. A number of violations of the conditions of keeping small cattle in the conditions of the farms under study were identified: crowded livestock, untimely change of bedding and manure cleaning, keeping young animals together with adult animals, as well as violations of microclimate conditions (reduced air velocity and increased concentration of inert gases harmful to animals). In addition, an important factor in the spread of pathogens of invasive diseases among animals on the farms under study is the deworming of livestock without taking into account the characteristics of the life cycle of parasites and the timing of their preimaginal stages, as well as the duration of endogenous and exogenous stages of development of protozoa of the Eimeria genus.Thus, causal relationships in the occurrence and circulation of pathogens of invasive diseases of small cattle among livestock in the territory of the farms of the Luga district of the Leningrad region were studied and determined, taking into account the climatic and geographical features of the area and the seasons of the year

Gelʼmintologicheskie issledovaniia zubrov Belovezhskoi pushchi v kontse XIX – nachale XX v.

The helminthofauna of the European bison, the iconic species for nature protection in Europe, is the object of close attention for zoologists because of the threatening changes occurring in this fauna in recent decades. Nowadays, researchers are more or less familiar with the works conducted in the early 20ʰᵗ century, i. e. before the European bison went extinct in the wild (1919), and the specialists involved in the European bison restitution in the Białowieża Primeval Forest and other nature reserves have been also aware of these studies. In addition to the published works on the European bison parasites, however, there exists a wide range of archival documents relating to the helminthoses of the Białowieża bison, including reliable information about parasitic worms as an important cause of death in the European bison, in particular, the trematode Fasciola hepatica. Apart from the literature analysis, our research focuses on the archival documents relating to helminthological studies conducted between the 1880s, when the European bison mortality caused by fascioliasis was reliably documented in the Białowieża Forest for the first time, and the 1910s, when an attending veterinarian was hired by the Białowieża administration to hold a permanent position for the first time. The most significant event in the history of the studies of the European bison helminthofauna before 1919 was the expedition to the Białowieża Primeval Forest, led by professor Nikolay Kulagin (1906–1908). The expedition’s permanent members were the entomologist Alexander Mordvilko and the veterinarian Konrad Wróblewski. They amassed an impressive amount of material that formed the basis for two monographs about the Białowieża bison (1919 and 1927, respectively). This expedition established that the main cause of the bison’s high mortality were the external factors including helminthoses rather than the degeneration of the species caused by the “laws of nature” (as was assumed for most of the 19ʰᵗ century).

The Fasciola hepatica egg development and hatching test (EDHT) using commercial drugs: a simple protocol for tackling anthelminthic resistance and promoting cattle productivity.

Fasciolosis is an important zoonotic disease caused by the trematode Fasciola hepatica, and it causes great losses in bovine production. The anthelmintic resistance is a major problem in the control of fasciolosis. In this study, the F. hepatica egg development and hatching test (EDHT) was used for the evaluation of the ovicidal activity of commercial drugs, commonly used for treating infected cattle, which reflects F. hepatica anthelminthic resistance in infected bovines, according to recent literature. Bile samples from F. hepatica naturally parasitized cattle were obtained from slaughterhouses in the cities of Lages and Otacílio Costa, Santa Catarina State, Brazil. The bile was washed, the eggs were recovered, quantified, and distributed in universal collectors, with a minimum of 1,000 eggs per vial. Four commercial drugs were used in this study, containing albendazole sulfoxide (ABDZ), closantel (CSTL), nitroxynil (NTXL), and triclabendazole with fenbendazole (TBZF). The drugs were diluted according to the manufacturer instructions. All drugs, and the respective control, were tested in triplicates, with the quantity of recovered eggs determining the number of drugs to be tested. The vials were incubated for 28days at 27°C, and the eggs were classified according to their degree of development under a stereomicroscope. In total, 121 egg samples were analyzed. Two samples were identified as resistant to TBZF. Undetermined resistance/susceptibility has been found in two isolates treated with ABDZ, one treated with NTXL and six treated with TBZF. CSTL did not present ovicidal activity and cannot be used in EDHT. This is the first time that commercial drugs were used in F. hepatica EDHT.

REPORT OF HUMAN FASCIOLIASIS UNDER DIFFERENT CLIMATIC CONDITIONS IN BRAZIL

Introduction: Human fascioliasis is a plant-borne and water-borne infection caused by the trematodes Fasciola hepatica and Fasciola gigantica. It is one of the main neglected tropical diseases, and infections in humans occur via the ingestion of contaminated water and food. This study reviews all the recorded cases of human fascioliasis in Brazil under different climatic conditions in the national territory. Methodology:A survey of human fascioliasis cases in Brazil was carried out using the Google Scholar, Lilacs and PubMed databases. The climatic variables such as temperature, precipitation, moisture and altitude were obtained from the database of the Instituto Nacional de Meteorologia (INMET). Results: Between the years 1958 and 2022, sixty-six cases of human fascioliasis were recorded in places with temperature levels between 22 °C to 33 °C, humidity 78% to 86%, precipitation 90 mm to 167 mm, and at an altitude of 16 to 935 meters above sea level. Conclusion: The parasite’s ability to adapt to different climatic conditions is observed in Brazil and the number of cases of human fascioliasis in the national territory may be higher due to underreporting related to the difficulty in diagnosing the infection.

Fasciola hepatica juveniles interact with the host fibrinolytic system as a potential early-stage invasion mechanism.

The trematode Fasciola hepatica is the most widespread causative agent of fasciolosis, a parasitic disease that mainly affects humans and ruminants worldwide. During F. hepatica infection, newly excysted juveniles (FhNEJ) emerge in the duodenum of the mammalian host and migrate towards their definitive location, the intra-hepatic biliary ducts. Understanding how F. hepatica traverses the intestinal wall and migrates towards the liver is pivotal for the development of more successful strategies against fasciolosis. The central enzyme of the mammalian fibrinolytic system is plasmin, a serine protease whose functions are exploited by a number of parasite species owing to its broad spectrum of substrates, including components of tissue extracellular matrices. The aim of the present work is to understand whether FhNEJ co-opt the functions of their host fibrinolytic system as a mechanism to facilitate trans-intestinal migration. A tegument-enriched antigenic extract of FhNEJ (FhNEJ-Teg) was obtained in vitro, and its capability to bind the zymogen plasminogen (PLG) and enhance its conversion to the active protease, plasmin, were analyzed by a combination of enzyme-linked immunosorbent, chromogenic and immunofluorescence assays. Additionally, PLG-binding proteins in FhNEJ-Teg were identified by bidimensional electrophoresis coupled to mass spectrometry analysis, and the interactions were validated using FhNEJ recombinant proteins. Our results show that FhNEJ-Teg contains proteins that bind PLG and stimulate its activation to plasmin, which could facilitate the traversal of the intestinal wall by FhNEJ and contribute to the successful establishment of the parasite within its mammalian host. Altogether, our findings contribute to a better understanding of host-parasite relationships during early fasciolosis and may be exploited from a pharmacological and/or immunological perspective for the development of treatment and control strategies against this global disease.

Parasitological contamination of two water sources in Adamawa-North Senatorial zone, Adamawa State, Nigeria

This study examined the parasitological contamination of well and river water sources, which are among the significant sources of water in the Adamawa-North Senatorial Zone. Water samples were collected aseptically from upstream and downstream of 4 rivers and 32 hand-dug wells between June 2019 to April 2020. The samples were examined for parasitic contamination by sedimentation and staining methods. A total of 149 (58.2%) parasites belonging to six species were detected. Of these, 85(66.4%) and 64(50.0%) were from river and well sources respectively. The parasites detected includes a trematode (Fasciola hepatica), a protozoan (Giardia lamblia), and four nematodes (Strongyloides stercoralis, Ascaris lumbricoides, Trichuris trichiura, and Ancylostoma duodenale). Ascaris lumbricoides was the most abundant parasite detected with a prevalence of 21.9%, and the least was F. hepatica (3.1%). The overall prevalence was higher in rainy season 85(66.4%) than in dry season 64(50.0%) but with no statistical difference (P=0.335). River water had the highest number of parasites in both rainy 47(73.4%) and dry seasons 38(59.4%). Also, river water in both dry and rainy periods had the highest number of A. lumbricoides, A. duodenale, T. trichiura, and F. hepatica. The highest number of S. stercoralis was detected only in the dry season of river water. Well water harbored the highest number of G. lamblia in dry and rainy seasons. Furthermore, A. lumbricoides was also highest in well water during the dry period. Based on Local Government Area (LGA), Mubi-North LGA had the highest number of parasites, but with no statistical difference from those of the other 3 LGAs (P=0.312). As observed in this study, the high prevalence of contamination by parasitic organisms of public health importance is of alarming concern. This is because there is no provision of pipe-borne water in the study area, and the available major sources of water may not be suitable for domestic use due to their high parasitic content.

Relapsed cholangitis revealing hepatic distomatosis in western Algeria apropos of a case

Fascioliasis is a worldwide but unevenly distributed zoonosis caused by the trematode Fasciola hepatica that infects domesticated herbivores. Fascioliasis also occurs accidentally in humans through ingestion of freshwater or aquatic plants laden with metacercariae. Human infections are common in developing countries and not uncommon in Europe, and rare in Algeria. The clinical evolution has been classically described in two phases: an acute phase of hepatic parenchymal invasion of an immature worm larva (parenchymal phase) and a stationary phase after stay in the bile duct and egg production (ductal phase). We report a case of a 50-year-old man from Tlemcen, western Algeria, with cholangitis (liver disorder, abdominal pain and jaundice). The diagnosis was confirmed by serology. The serological examination (Western Blot) was positive and the results of magnetic resonance imaging were compatible with fascioliasis.

Identification and Molecular Characterization of Trematode and Nematode in Fleas Infesting Small Ruminants in Egypt

The present study aimed to determine the prevalence and distribution of flea-infested ruminants in Egypt's Northern West Coast (NWC) and South Sinai Governorate (SSG), besides the molecular characterization and genotypes of Nematode and Trematode in the identified flea species. In total, 765 animals of both sexes and ages (471 from NWC and 294 from SSG) were examined for flea infestation, including 460 sheep and 305 goats. Microscopically, flea species were identified; while nematodes and trematodes were identified using sequence analysis of purified PCR fragments of the small subunits 18S of nuclear ribosomal DNA (18S rDNA) and the internal transcribed spacer region of the ribosomal RNA (ITS2) gene primers. The results revealed that the cat flea, Ctenocephalides felis, and the dog flea, Ctenocephalides canis, were widely distributed in sheep and goat flocks throughout the corresponding areas. While age, sex, and host had no significant differences (P > 0.5), the location, flea species, and season of flea collection all had an impact on the predominance of the two flea species. Additionally, there were significant differences between C. felis and C. canis infestations in the two areas, and only among the sexes of both flea species in the NWC. Molecular data confirmed one trematode (Fasciola hepatica) in both C. felis and C. canis, whereas two nematode species were identified: Haemonchus contortus only in sheep in both areas and Trichostrongylus colubriformis only in C. canis infesting goats in SSG. Sequenced isolates were assigned in the GenBank database under accession numbers ON123999, ON123994, ON123995, and ON123993 (F. hepatica), ON113484, ON113485, and ON113486 (H. contortus), and ON113498 (T. colubriformis). We conclude that the presence of those pathogens in fleas in the two areas required special attention to periodic flea control programmes and anthelmintic treatments, as well as further evaluation of the epidemiology and role of fleas.

Proteomics coupled with in vitro model to study the early crosstalk occurring between newly excysted juveniles of Fasciola hepatica and host intestinal cells.

Fasciolosis caused by the trematode Fasciola hepatica is a zoonotic neglected disease affecting animals and humans worldwide. Infection occurs upon ingestion of aquatic plants or water contaminated with metacercariae. These release the newly excysted juveniles (FhNEJ) in the host duodenum, where they establish contact with the epithelium and cross the intestinal barrier to reach the peritoneum within 2–3 h after infection. Juveniles crawl up the peritoneum towards the liver, and migrate through the hepatic tissue before reaching their definitive location inside the major biliary ducts, where they mature into adult worms. Fasciolosis is treated with triclabendazole, although resistant isolates of the parasite are increasingly being reported. This, together with the limited efficacy of the assayed vaccines against this infection, poses fasciolosis as a veterinary and human health problem of growing concern. In this context, the study of early host-parasite interactions is of paramount importance for the definition of new targets for the treatment and prevention of fasciolosis. Here, we develop a new in vitro model that replicates the first interaction between FhNEJ and mouse primary small intestinal epithelial cells (MPSIEC). FhNEJ and MPSIEC were co-incubated for 3 h and protein extracts (tegument and soma of FhNEJ and membrane and cytosol of MPSIEC) were subjected to quantitative SWATH-MS proteomics and compared to respective controls (MPSIEC and FhNEJ left alone for 3h in culture medium) to evaluate protein expression changes in both the parasite and the host. Results show that the interaction between FhNEJ and MPSIEC triggers a rapid protein expression change of FhNEJ in response to the host epithelial barrier, including cathepsins L3 and L4 and several immunoregulatory proteins. Regarding MPSIEC, stimulation with FhNEJ results in alterations in the protein profile related to immunomodulation and cell-cell interactions, together with a drastic reduction in the expression of proteins linked with ribosome function. The molecules identified in this model of early host-parasite interactions could help define new tools against fasciolosis.

Fasciola hepatica Fatty Acid Binding Protein 1 Modulates T cell Polarization by Promoting Dendritic Cell Thrombospondin-1 Secretion Without Affecting Metabolic Homeostasis in Obese Mice.

BackgroundThe parasitic trematode Fasciola hepatica evades host immune defenses through secretion of various immunomodulatory molecules. Fatty Acid Binding Proteins (fhFABPs) are among the main excreted/secreted proteins and have been shown to display anti-inflammatory properties. However, little is currently known regarding their impact on dendritic cells (DCs) and their subsequent capacity to prime specific CD4+ T cell subsets.Methodology/Principal FindingsThe immunomodulatory effects of both native F. hepatica extracts and recombinant fhFABPs were assessed on monocyte-derived human DCs (moDCs) and the underlying mechanism was next investigated using various approaches, including DC-allogenic T cell co-culture and DC phenotyping through transcriptomic, proteomic and FACS analyses. We mainly showed that fhFABP1 induced a tolerogenic-like phenotype in LPS-stimulated moDCs characterized by a dose-dependent increase in the cell-surface tolerogenic marker CD103 and IL-10 secretion, while DC co-stimulatory markers were not affected. A significant decrease in secretion of the pro-inflammatory cytokines IL-12p70 and IL-6 was also observed. In addition, these effects were associated with an increase in both Th2-on-Th1 ratio and IL-10 secretion by CD4+ T cells following DC-T cell co-culture. RNA sequencing and targeted proteomic analyses identified thrombospondin-1 (TSP-1) as a non-canonical factor highly expressed and secreted by fhFABP1-primed moDCs. The effect of fhFABP1 on T cell skewing was abolished when using a TSP-1 blocking antibody during DC-T cell co-culture. Immunomodulation by helminth molecules has been linked to improved metabolic homeostasis during obesity. Although fhFABP1 injection in high-fat diet-fed obese mice induced a potent Th2 immune response in adipose tissue, it did not improved insulin sensitivity or glucose homeostasis.Conclusions/SignificanceWe show that fhFABP1 modulates T cell polarization, notably by promoting DC TSP-1 secretion in vitro, without affecting metabolic homeostasis in a mouse model of type 2 diabetes.

Ecological and parasitological characteristics of the “Fasciola hepatica L.–Lymnaea (Galba) subangulata” system

Background. Fasciolosis is one of the most common zoonoses in the world, caused by the trematode Fasciola hepatica L. This helminthiasis leads to significant economic damage in animal husbandry and can pose a direct threat to human health. Today, in the context of climate change, detailed knowledge of the biological characte­ristics of the trematode F. hepatica circulation will make it possible to predict outbreaks of fasciolosis on farms in detail and plan effective measures to combat this dangerous disease. The purpose of this work is to clarify some aspects of F. hepatica biology within Berdychiv district belonging to the forest-steppe zone of Zhytomyr region. Material and Methods. The work was carried out during 2020–2021. Collections of mollusks from water bodieson the territory of Berdichevsky district of Zhytomyr region served as the material for the research. Their identification was carried out by conchological features. Conventional methods were used for the parasitological study of mollusks. In total, more than 2000 mollusks Lymnaea (Galba) spp. were examined. Sampling of water and mollusks was carried out from four pasture reservoirs. Results. The main intermediate host of F. hepatica is the mollusk L. (G.) subangulata in the territory of Berdychiv region; L. (G.) truncatulaplays a secondary role in the distribution of this trematode. It was noted that the carriers of F. hepatica partenites are mainly mollusks with a shell height of 4.0 to 8.2 mm. New data on the dynamics of infection of L. (G.) subangulata with the trematode F. hepatica was obtained. The dynamics of infestation of these mollusks with F. hepatica cercariae shows a stable uniform character in the form of a two-peak curve, with peaks in May (2.51 ± 0.88 %) and August (9.19 ± 1.78 %). The overall prevalence of L. (G.) subangulata invasion by fasciola cercariae in the studied water bodies in 2020 was significantly lower than in 2021. Conclusions. In modern climatic conditions, in the territory of the region, permanent water bodies have become fasciolosis foci and common places for the settlement of L. (G.) subangulata, infected with F. hepatica cercariae. The most favorable environmental conditions for fasciola and its intermediate hosts develop in spring; accordingly; for the definitive hosts, this period is quite dangerous in terms of infection of animals.

A machine learning approach for modelling the occurrence of Galba truncatula as the major intermediate host for Fasciola hepatica in Switzerland

Fasciolosis caused by the trematode Fasciola hepatica is an important parasitosis in both livestock and humans across the globe. Chronic infections in cattle are associated with considerable economic losses. As a prerequisite for an effective control and prevention of fasciolosis in cattle fine-scale predictive models on farm-level are needed. Since disease transmission will only occur where the mollusc intermediate host is present, the objective of our research was to develop a regression model that allows to predict the local presence or absence of Galba truncatula as principal intermediate host for Fasciola hepatica in Switzerland. By implementing generalized linear mixed models (GLMMs) a total amount of 70 variables were analysed for their potential influence on the likelihood πi of finding Galba truncatula at a certain site. Important site-specific features could be considered by selecting suitable modelling procedures. The statistical software R was used to conduct regression analysis, performing the grplasso and the glmmLasso method. The selection of parameters was based on 10-fold cross validation and the Bayesian Information Criterion (BIC). This yielded a total number of 19 potential predictor variables for the grplasso and 13 variables for the glmmLasso model, which also included random effects. Nine variables appeared to be relevant predictors for the occurrence of Galba truncatula in both models. These included reed/humid area, spring water, water bodies within a 100 m radius, and trees/bushes as powerful positive predictors. High soil depth, temperatures frequently exceeding 30 °C in the year preceding the search for snails and temperatures below 0 °C especially in the second year before were identified to exert an adverse effect on the occurrence of Galba truncatula. Temperatures measured near ground level proved to be more powerful predictors than macroclimatic parameters. Precipitation values seemed to be of minor impact in the given setting. Both regression models may be convenient for a fine-scale prediction of the occurrence of Galba truncatula, and thus provide useful approaches for the development of future spatial transmission models, mapping the risk of fasciolosis in Switzerland on farm-level.

Fascioliasis prevalence in livestock from abattoirs in southern Chile

Fascioliasis is a widely distributed parasitic zoonosis caused by the trematode Fasciola hepatica that affects livestock production and generates high economic losses. In Chilean authorised abattoirs, the infected livestock livers are condemned during the veterinary inspection. This study aims to evaluate the prevalence of fascioliasis in Chile from 2014 to 2016 and also monthly from 2002 to 2015 in livestock (cattle, pig, sheep, horse and goat) slaughtered in abattoirs of La Araucanía region, southern Chile. To do this, the available records on abattoirs provided by the sanitary authority were analysed. A descriptive statistics and trend analysis of the data by jointpoint regression was carried out. The Biobío and La Araucanía regions registered the highest levels of parasitosis in the country recording levels of 59.18 and 44.74%, respectively, and presented 50.03% of the liver condemnation rate in cattle. During the study period, a total of 2,239,164 animals were slaughtered and 40.59% infected livers with F. hepatica were condemned in the 9 existing abattoirs of La Araucanía region. The abattoirs located in the cities of Temuco (51.43%) and Angol (65.09%) recorded the highest percentages of fascioliasis. The cattle species recorded the highest number of slaughtered animals and liver condemnation (54.52%). The presence of the parasite was recorded annually and monthly and it was possible to observe a slight increase in fascioliasis over the years. This study provides updated information on the fascioliasis prevalence in the country and the dynamics of condemnation in endemic areas such as La Araucanía region, which could contribute to the control and prevention of this zoonosis.

Study of triclabendazole effects on Fasciola hepatica’s life-supporting organs, spines and suckers responsible for stable position of the parasite in the host

The purpose of the research is to study triclabendazole effects on the Fasciola’s life-supporting organs, spines and suckers which are responsible for stable position of the parasite in the host.Materials and methods. The study material was trematodes Fasciola hepatica (Linneus 1758, family Fasciolidae Railliet 1895), which were collected after the action of triclabendazole (fasinex) (chemically 5-chloro-6-(2,3-dichlorophenoxy)-2-methylthiobenzimidazole)on the 7th day after the drug administered at a single dose of 10 mg/kg for the Active Substance in the treatment of ovine fasciolosis. F. hepatica from untreated animals served as control. Mature F. hepatica collected after treatment with triclabendazole, and marita from the control groups were dehydrated in ascending alcohol series for 1–2 days after fixation; then passed through a mixture of chloroform and absolute alcohol (in a ratio of 1:1), and through pure chloroform in two portions for 10–15 minutes. The material was then soaked in a mushy mixture of chloroform and paraffin in a thermostat at 37 °C for 12–18 hours, and in paraffin in a thermostat at 56 °C for 30–45 minutes; and then embedded in paraffin with added wax. The resulting paraffin blocks were broken down into serial sections of 5–7 μm thick, then stained and examined under a light microscope.Results and discussion. Pathomicromorphological analysis of F. hepatica’s spines and suckers, organs that come into adhesive contact with the host organism revealed destructive changes in them after the action of triclabendazole. After the action of triclabendazole on fascioles, the spines look enlarged and swollen, and have a more rounded shape and some changes in color, absorbing eosin in greater concentration. The muscle fibers of the fascioles’ oral and abdominal suckers also look swollen after the action of triclabendazole. Although the musculature of the F. hepatica’s pharynx retained its structure, it has changes. It thickened sharply, which is clearly visible on the transverse and longitudinal sections of the helminths; neurosecretory cells are destroyed, and voids are observed in their place.

Recognition Pattern of the Fasciola hepatica Excretome/Secretome during the Course of an Experimental Infection in Sheep by 2D Immunoproteomics.

Excretory/secretory products released by helminth parasites have been widely studied for their diagnostic utility, immunomodulatory properties, as well as for their use as vaccines. Due to their location at the host/parasite interface, the characterization of parasite secretions is important to unravel the molecular interactions governing the relationships between helminth parasites and their hosts. In this study, the excretory/secretory products from adult worms of the trematode Fasciola hepatica (FhES) were employed in a combination of two-dimensional electrophoresis, immunoblot and mass spectrometry, to analyze the immune response elicited in sheep during the course of an experimental infection. Ten different immunogenic proteins from FhES recognized by serum samples from infected sheep at 4, 8, and/or 12 weeks post-infection were identified. Among these, different isoforms of cathepsin L and B, peroxiredoxin, calmodulin, or glutathione S-transferase were recognized from the beginning to the end of the experimental infection, suggesting their potential role as immunomodulatory antigens. Furthermore, four FhES proteins (C2H2-type domain-containing protein, ferritin, superoxide dismutase, and globin-3) were identified for the first time as non-immunogenic proteins. These results may help to further understand host/parasite relationships in fasciolosis, and to identify potential diagnostic molecules and drug target candidates of F. hepatica.

FORMATION OF BIODIVERSITY OF THE FAUNA OF ECTO- AND ENDOPARASITES ON THE ARARAT PLAIN OF ARMENIA

Our studies were aimed at analyzing biodiversity of ecto- and endoparasites of sheep, cattle, rabbits, domestic birds and dogs in the lowland zone of the Republic, with semidesert climate and height of 850 m above the sea level. This is one of the warm regions of the Republic. The studies performed have established moderate and high degree of animal infection with parasites. We identified 33 parasite species, mostly helminths (15 species), including 10 species of nematodes (Trichocephalus ovis, Nematodirus spathiger, Haemonchus contortus, Chabertia ovina, Dictyocaulus filaria, Muellerius capillaris, Protostrongylus spp., Passalurus ambiqus, Ascaridia galli, Heterakis gallinarum), 4 species of trematodes (Fasciola hepatica, F. gigantica, Dicrocoelium dendriticum, Paramphistomum cervi), 1 species of cestodes (Moniezia expansa), 9 protozoan species (Piroplasma bigeminum, Babesia ovis, Eimeria perforans, E. magna, E. irresidua, E. tenella, E. acervulina), 7 species of ticks, 1 species of insects, and 1 species of leishmaniasis vector, the mosquitos from the genus Phlebotomus. We registered 5 species of freshwater molluscs (Lymnaea auricularia, L. stagnalis, L. ovata, L. truncatula, Planorbis planorbis), and 2 species of terrestrial molluscs (Helicella derbentina, Napaeopsis hohenackeri).

Diagnosis and Risk Factors of Bovine and Human Fascioliasis in Cattle Farms from a Venezuelan Andean Rural Area.

Fascioliasis is caused in Venezuela by the trematode Fasciola hepatica, affecting herbivorous and human. The Venezuelan Andean region is endemic for bovine fascioliasis and its presence in humans is not known. The objective of this work was to detected positive cases of bovine and human fascioliasis by coprological and immunological techniques and determine the possible risk factors, in eight cattle farms of a Venezuelan Andean rural area. We studied 143 samples of feces and sera of bovines, and 34 samples of feces and sera of humans. Feces were examined by several coprologic techniques, while sera were evaluated by ELISA using two antigens: crude extract (CE) and surface proteins (SP) of F. hepatica, which were previously standardized and validated. The frequency of fascioliasis in bovines was 21% by coprology, and 49.7% by SP-ELISA. The human detection was 0% by coprology, and 29.4% by SP-ELISA. There were statistical significative differences between cattle farms, regarding to the positive results by coprology and by SP-ELISA. About the possible risk factors, statistical association was found only with the presence of snails near or in the farms and consumption of non-channeled water (river, ditch or spring), both for cattle and for humans. The results showed that the studied area is endemic for bovine fascioliasis, the human has been in contact with F. hepatica and there are risk factors for the transmission of the parasite in the studied farms.

Serine proteases activity in miracidia of Fasciola hepatica and effects of chemical and herbal inhibitors.

Fasciolosis is a zoonotic parasitic disease caused by the trematode Fasciola hepatica. The proteases are essential for the survival of parasites. The present study was aimed to determine serine proteases activities in miracidia of F. hepatica and evaluate the effects of pH and different inhibitors on the serine proteases activities. Adult F. hepatica helminths were removed from naturally infected livers of the slaughtered cattle and crushed. The eggs were incubated at 28.00 ˚C for 16 days. The released miracidia were homogenized and total proteolytic activity of the extract of miracidia at different pH values were evaluated. Serine proteases activities were determined using specific substrates. The inhibitory effects of chemical and herbal inhibitors on the enzymes were also assessed. The extract of miracidia hydrolyzed azocasein with optimum activity at pH 8.00. The optimum pH effect on serine proteases activities was found at alkaline pH. Phenylmethylsulfonyl fluoride and Bowman-Birk inhibitors inhibited and decreased the proteases activities in the miracidia extract. It was concluded that there were proteases activities in miracidia of F. hepatica which were inhibited by chemical and herbal inhibitors.