Intestinal Trematode Infections

Intestinal trematodes are among the most common types of parasitic worms. About 76 species belonging to 14 families have been recorded infecting humans. Infection commonly occurs when humans eat raw or undercooked foods that contain the infective metacercariae. These parasites are diverse in regard to their morphology, geographical distribution and life cycle, which make it difficult to study the parasitic diseases that they cause. Many of these intestinal trematodes have been considered as endemic parasites in the past. However, the geographical limits and the population at risk are currently expanding and changing in relation to factors such as growing international markets, improved tran…

Cestodiasis inusual en infante español

Extracellular vesicles from parasitic helminths contain specific excretory/secretory proteins and are internalized in intestinal host cells.

The study of host-parasite interactions has increased considerably in the last decades, with many studies focusing on the identification of parasite molecules (i.e. surface or excretory/secretory proteins (ESP)) as potential targets for new specific treatments and/or diagnostic tools. In parallel, in the last few years there have been significant advances in the field of extracellular vesicles research. Among these vesicles, exosomes of endocytic origin, with a characteristic size ranging from 30-100 nm, carry several atypical secreted proteins in different organisms, including parasitic protozoa. Here, we present experimental evidence for the existence of exosome-like vesicles in parasitic…

Immunology and pathology of echinostome infections in the definitive host.

This chapter examines the salient literature on the immunology and pathology of members of the family Echinostomatidae in their definitive hosts, with emphasis on experimental studies that may provide useful information on factors that determine resistance to the parasites. For this purpose, several topics such as manifestations and mechanisms of resistance to infection, experimental strategies, and antigenic characterization of echinostomes are covered. Moreover, other topics such as immunodiagnosis are also analyzed. The analysis is focused on members of the genus Echinostoma. Although some of the nomenclature for echinostome species is disputed, the names used are those currently accepte…

The influence of adult worm age and definitive host on the transmission of Echinostoma caproni: egg hatchability and miracidial infectivity.

AbstractWe analysed the influence of different ages of Echinostoma caproni adult worms reared in different definitive host-species on egg hatchability and miracidial infectivity. Eggs obtained from 2-, 4- and 6-week-old adult worms collected from rats, hamsters and mice, hatched miracidia that were used to infect laboratory-reared specimens of Biomphalaria glabrata. Highest egg hatchability was obtained with eggs derived from hamsters and mice. Egg hatchability did not seem to be affected by the age of E. caproni adult worms. Miracidial infectivity was not affected by the definitive host species. However, miracidial infectivity was affected by the age of adult worms when they developed in t…

Echinostoma caproni: Differential tegumental responses to growth in compatible and less compatible hosts

Abstract The topography of the tegument of Echinostoma caproni adults collected from high (mice) and low (rats) compatible hosts was compared by SEM. In the oral (OS) and the ventral sucker (VS) areas, a worm age–host species interaction was found with regard to the density of spines. There was a decrease in the density of spines in the adults collected from mice, whereas an increase occurred in the OS area in worms from rats over time. The tegumentary spines in adults from mice became larger and blunter. Some spines from the VS area in adults from mice at 4 wpi were multipointed. The spines of adults from rats were sharper, not covered by the tegument and no multipointed spines were observ…

Additional file 1 of Interleukin-25-mediated resistance against intestinal trematodes does not depend on the generation of Th2 responses

Additional file 1: Table S1. Applied Biosystems Inventoried assays used in the present work.

An experimental study of the reproductive success of Echinostoma friedi (Trematoda: Echinostomatidae) in the golden hamster

Viable eggs produced weekly per infective stage was used as a measure of the reproductive success of Echinostoma friedi during the first 12 weeks of infection in hamsters. The weekly reproductive success was not constant during the experiment in relation to the egg output and the proportion of viable eggs produced. The egg release started during week 2 post-inoculation, attaining a maximum during week 3. A decline in egg output was observed from week 9. Viable eggs were only produced from week 3 post-inoculation and a maximum was attained at week 4 of the experiment. A decline in egg viability was observed from week 9. Considering together the egg output and the egg viability, the maximum w…

Specific tyrosine phosphorylation in response to bile in Fasciola hepatica and Echinostoma friedi

Protein tyrosine phosphorylation (PY) is a well-known signalling mechanism which is also involved in host-parasite interactions. Despite its transcendence, PY has been poorly studied in parasitic helminths. The aim of this study is to examine the effect of bile salts on the PY pattern in parasitic trematodes. Two distinct adult models were analysed: Echinostoma friedi, of intestinal habitat, and Fasciola hepatica, naturally inhabitant of host biliary channels. Our results show that bile salts induce specific and distinct protein PY in both trematode species, indicating that this signalling process seems to be also involved in host-trematode relationships.

Definitive host influences the proteomic profile of excretory/secretory products of the trematode Echinostoma caproni

Background Echinostoma caproni is an intestinal trematode extensively used as experimental model for the study of factors that determine the course of intestinal helminth infections, since this markedly depends on the host species. Although the host-dependent mechanisms for either chronic establishment or early parasite rejection have been broadly studied, little is known regarding the parasite response against different host environments. Methods To identify host-dependent differentially expressed proteins, a comparative proteomic analysis of the excretory/secretory products released from E. caproni adults, isolated from hosts displaying different compatibility with this trematode, was per…

Additional file 1: of Prevalence of intestinal parasites, with emphasis on the molecular epidemiology of Giardia duodenalis and Blastocystis sp., in the Paranaguá Bay, Brazil: a community survey

Table S1. Oligonucleotides used for the molecular identification and/or characterisation of Giardia duodenalis and Blastocystis sp. in this study. (DOCX 17 kb)

Kinetics of antibodies and antigens in serum of mice experimentally infected with echinostoma caproni (trematoda: echinostomatidae)

The present study reports on the kinetics of antibodies and antigens in serum of mice experimentally infected with 75 metacercariae of Echinostoma caproni during the first 12 wk postinfection (wpi). Antibody titers in the serum of mice were determined by an indirect enzyme-linked immunosorbent assay (ELISA) using excretory/secretory (ES) antigens of E. caproni. The early detection of antibodies against ES antigens of E. caproni is feasible using indirect ELISA. Mice developed significant antibody responses at 2 wpi, and the values progressively increased until the end of the experiment. This may be related to the intestinal absorption of adult worm antigens that induces humoral responses. T…

Criteria for species determination in the 'revolutum' group of Echinostoma.

Survival and infectivity of Hypoderaeum conoideum and Euparyphium albuferensis cercariae under laboratory conditions.

The survival characteristics of the cercariae of Hypoderaeumconoideum and Euparyphiumalbuferensis (Trematoda: Echinostomatidae) at 20°C and 30°C are described, and the age dependency of their infectivity at 20°C is studied to determine their respective transmission efficiencies. Cercarial survival was found to be age-dependent and was higher at 20°C. For both cercariae, the maximum life-span was 26 h at 20°C and 16 h at 30°C, and their respective times to 50% mortality were similar at each temperature. Both cercariae seem to be well adapted to transmission in their natural habitat, though cercarial infectivity of H. conoideum was higher than that of E. albuferensis, this being correlated wi…

Molecular cloning and characterization ofEchinostoma caproniheat shock protein-70 and differential expression in the parasite derived from low- and high-compatible hosts

SUMMARYWe cloned and expressedEchinostoma caproniHSP70 inEscherichia coli. This molecule presents an open reading frame (ORF) of 655 amino acids, and a theoretical molecular weight of 71 kDa.E. caproniHSP70 protein showed a high homology to other helminth molecules, major differences being located in the C-terminal region of the molecule, with a hydrophobic portion. Studies of protein and messenger RNA (mRNA) expression revealed a distinct pattern, depending on the host (low- or high-compatible). Specific polyclonal antisera raised against the recombinant protein expressed inEscherichia colidemonstrated its selective presence in excretory/secretory products (ESP) of adult parasites obtained…

A QUANTITATIVE APPROACH TO THE EXPERIMENTAL TRANSMISSION SUCCESS OF ECHINOSTOMA FRIEDI (TREMATODA: ECHINOSTOMATIDAE) IN RATS

Using a range of parameters, the ability of rats (Rattus norvegicus) to successfully transmit Echinostoma friedi to the next host was examined under experimental conditions. The concept of Experimental Transmission Success (TM), defined as the number of hosts that become successfully infected after exposure to a number of infective stages produced by a previous host per unit of inoculation at which this latter host was exposed, was introduced. Using data for the egg output and miracidium hatching and infectivity, the TM permits us to estimate the ability of a particular defintive host species to successfully transmit a parasite species. This concept may be also useful to compare the transmi…

Strongyloidiasis with Emphasis on Human Infections and Its Different Clinical Forms

Strongyloidiasis (caused by Strongyloides stercoralis, and to a lesser extent by Strongyloides fuelleborni) is one of the most neglected tropical diseases with endemic areas and affecting more than 100 million people worldwide. Chronic infections in endemic areas can be maintained for decades through the autoinfective cycle with the L3 filariform larvae. In these endemic areas, misdiagnosis, inadequate treatment and the facilitation of the hyperinfection syndrome by immunosuppression are frequent and contribute to a high mortality rate. Despite the serious health impact of strongyloidiasis, it is a neglected disease and very little is known about this parasite and the disease when compared …

Echinostoma caproni: intestinal pathology in the golden hamster, a highly compatible host, and the Wistar rat, a less compatible host.

The histopathological changes induced by Echinostoma caproni (Trematoda: Echinostomatidae) in a high (golden hamster) and a low compatible host (rat) were compared at 15 and 30 days post-infection. Infection of rats was characterized by a progressive increase in erosion of villi and elevated numbers of goblet cells, which could be related to the early expulsion of the parasite in a host of low compatibility. In contrast to rats, the number of goblet cell in E. caproni-infected hamsters was low, but increased numbers of neutrophils and mesenteric inflammatory cells were observed. This indicated that local inflammatory responses in hamsters were greater than in rats. An immunohistochemical st…

Th2 and Th1 Responses: Clear and Hidden Sides of Immunity Against Intestinal Helminths.

Intestinal helminthiases affect millions of people worldwide, mainly in developing regions, where they cause a significant negative impact on human health and socioeconomic growth of affected populations. However, intestinal helminthiases are still among the most neglected tropical diseases. Protective immunity against intestinal helminths is associated with development of type 2 responses. Nevertheless, in some host–intestinal helminth combinations, local Th1 responses are initiated, inducing chronicity. The usage of helminth–mouse models is useful for elucidating the mechanisms behind the initiation of each type of response. Herein, the current knowledge on these topics is reviewed, payin…

Exploiting Helminth–Host Interactomes through Big Data

Helminths facilitate their parasitic existence through the production and secretion of different molecules, including proteins. Some helminth proteins can manipulate the host's immune system, a phenomenon that is now being exploited with a view to developing therapeutics for inflammatory diseases. In recent years, hundreds of helminth genomes have been sequenced, but as a community we are still taking baby steps when it comes to identifying proteins that govern host-helminth interactions. The information generated from genomic, immunomic, and proteomic studies, as well as from cutting-edge approaches such as proteogenomics, is leading to a substantial volume of big data that can be utilised…

Teniasis en una niña española

Sympatric and allopatric experimental infections of the planorbid snail Gyraulus chinensis with miracidia of Euparyphium albuferensis (Trematoda: Echinostomatidae).

AbstractAn experimental infection with echinostomatid miracidia in sympatric or ‘local’ vs. allopatric or ‘away’ snail combinations, as a model to examine parasite compatibility, was carried out. We employedEuparyphium albuferensismiracidia to infectGyraulus chinensissnails, from three different natural parks: Albufera (Valencia, Spain); the Ebro Delta (Tarragona, Spain) and Coto de Doñana (Huelva, Spain). Insignificant differences between the three snail strains were noted for the infection rate and the rhythm of daily cercarial production. However, a significantly higher total cercarial production per snail, patent period and life span were observed in local snails. The different infectio…

Additional file 1: of Definitive host influences the proteomic profile of excretory/secretory products of the trematode Echinostoma caproni

Detailed gel images of the differential spots identified by mass spectrometry and database search. Magnification of the 2D gel-areas corresponding to the 19 differentially expressed spots identified by mass spectrometry and database search. Detailed images for each of the 6 replicates analyzed (3 corresponding to the ESPs of E. caproni adults obtained from rats, and 3 from those isolated from mice) are shown. Spot numbers refer to gel image in Fig. 2. (PPTX 4834 kb)

Kinetics of echinostoma caproni (trematoda: echinostomatidae) antigens in feces and serum of experimentally infected hamsters and rats

This study reports on the kinetics of antibody production to Echinostoma caproni and the dynamics of antigens in feces and sera in 2 experimental hosts (hamsters and rats) that display different degrees of susceptibility with this echinostome. Echinostoma caproniproduced chronic infections in hamsters, whereas rats lost the infection at 49-56 days postinfection (DPI). Hamsters developed higher antibody responses than rats, probably in relation to different intestinal absorptions of worm antigens in each host species. The levels of coproantigens were indicative of the course of infection in each host. Positive coproantigen levels were detected at 1-2 DPI in both hosts, and the values remaine…

Additional file 2: of Definitive host influences the proteomic profile of excretory/secretory products of the trematode Echinostoma caproni

Details of the computational comparison of the excretory/secretory proteomes. Description of data: Quantitative and statistical details of the computational comparison of excretory/secretory proteomes of Echinostoma caproni adult worms isolated from mice and rats using Progenesis SameSpots software (version 4.5) (Nonlinear Dynamics Ltd.). Spot numbers refer to gel image in Fig. 2. (DOCX 13 kb)

Miracidial infectivity of Hypoderaeum conoideum (Trematoda: Echinostomatidae): differential susceptibility of two lymnaeid species.

A study was made of the infectivity of Hypoderaeum conoideum miracidia to a range of laboratory-reared specimens of freshwater snail species (Lymnaea peregra, L. corvus, Physella acuta, and Gyraulus chinensis) that coexist with the parasite in the same natural habitat. L. peregra and L. corvus were found to be equally susceptible to the parasite when specimens of each snail species were singly exposed to miracidia. However, when miracidia could choose either lymnaeid species, they showed a high degree of specificity toward L. peregra. The results obtained suggest that H. conoideum miracidia are capable of distinguishing among these lymnaeids in their orientation to the host. This indicates …

Differential alterations in the small intestine epithelial cell turnover during acute and chronic infection with Echinostoma caproni (Trematoda)

Background The intestinal epithelium plays a multifactorial role in mucosal defense. In this sense, augmented epithelial cell turnover appears as a potential effector mechanism for the rejection of intestinal-dwelling helminths. Methods A BrdU pulse-chase experiment was conducted to investigate the infection-induced alterations on epithelial cell kinetics in hosts of high (mouse) and low (rat) compatibility with the intestinal trematode Echinostoma caproni. Results High levels of crypt-cell proliferation and tissue hyperplasia were observed in the ileum of infected mice, coinciding with the establishment of chronic infections. In contrast, the cell migration rate was about two times higher …

Immunology and Pathology of Intestinal Trematodes in Their Definitive Hosts

This review examines the significant literature on the immunology and pathology of intestinal trematodes in their definitive hosts. We emphasize information on selected species in six families for which the literature on these topics is extensive. The families are Brachylaimidae, Diplostomidae, Echinostomatidae, Gymnophallidae, Heterophyidae, and Paramphistomidae. For most of these families, coverage is considered under the following headings: (i) background; (ii) pathology of the infection; (iii) immunology of the infection; (iv) immunodiagnosis; and (v) human infection. Some of these heading have been subdivided further, based on the literature available on a particular topic. Following t…

A case report of human gastrodiscoidiasis in Nepal.

Gastrodiscoidiasis is a snail-transmitted zoonotic infection caused by the digenean trematode Gastrodiscoides hominis, which is the only species in the genus Gastrodiscoides infecting humans. We report a case of human gastrodiscoidiasis in a 66 years-old Nepali man without history of travels outside of Nepal who was admitted in the hospital with pain in upper abdomen for 4 months with history of passage of black-tarry stools, anemia and eosinophilia. During upper endoscopy a living trematode worm was seen in the antrum of the stomach. After isolation, the worm was identified morphologically as Gastrodiscoides hominis. Stool analysis of the patient revealed eggs of this parasite. The cause o…

Echinostomes as experimental models for interactions between adult parasites and vertebrate hosts.

Echinostomes are intestinal trematodes that, for years, have served as experimental models in different areas of parasitology. However, the usefulness of these trematodes in experimental parasitology has been underappreciated. In this article, we examine the characteristics that make echinostomes useful models for analysis of the interactions between adult parasites and vertebrate hosts, particularly in relation to the host-related factors that determine the establishment of the parasites.

Hookworm-like eggs in children’s faecal samples from a rural area of Rwanda

Background: Hookworm eggs identification and quantification is usually carried out by Kato-Katz method. However various structures present in the smear may be confused with eggs of such parasites. Objective: To document the presence of structures in Kato-Katz slides that could initially be misinterpreted as hookworm eggs. Method: 497 faecal samples were analysed by Kato-Katz technique, diphasic concentration technique, agar-plate coprocultive and larvae obtained were analysed by PCR and characterized by sequencing. Result: Hookworm-like eggs were found in 159 (32%) of the samples by Kato Katz, finally identified as Caenorhabditis elegans by PCR technique. Conclusion: The diagnosis of human …

Identification of proteins in excretory/secretory extracts of Echinostoma friedi (Trematoda) from chronic and acute infections.

In the present study, we describe the investigation of Echinostoma friedi excretory/secretory products using a proteomic approach combined with the use of heterologous antibodies. We have identified 18 protein spots corresponding to ten proteins, including cytoskeletal proteins like actin, tropomyosin, and paramyosin; glycolytic enzymes like enolase, glyceraldehyde 3P dehydrogenase, and aldolase; detoxifying enzymes like GSTs; and stress proteins like heat shock protein (Hsp) 70. Among these proteins, both actin and, to a lesser extent, Hsp70, exhibited differential expression patterns between chronic and acute infections in the Echinostoma-rodent model, suggesting that these proteins may p…

An Autochthonous Human Case of Fasciolopsiasis in Nepal

Fasciolopsiasis is rarely known as the parasitic disease in Nepal. Herein, we report a case of fasciolopsiasis in a 22-year-old man who was admitted in the hospital with abdominal pain, distension and loss of appetite for a month. He had previously diagnosed with acute viral hepatitis but, his abdominal pain was not resolving despite improvement in his liver function and general condition. During endoscopy an adult digenean worm was seen in the first part of the duodenum. After isolation, the worm was identified morphologically as Fasciolopsis buski. Microscogic examination of the patient's stool revealed eggs with a morphology consistent with F. buski. Eggs were yellow-brown, ellipsoidal, …

Production and chronobiology of emergence of the cercariae of Euparyphium albuferensis (Trematoda: Echinostomatidae).

The production and the chronobiology of emergence of the cercariae of Euparyphium albuferensis from Gyraulus chinensis experimentally infected with a single miracidium were established during 28 consecutive days from the first day of cercarial shedding. Moreover, the effect of a sudden change in light-dark cycling was investigated. Although the daily cercarial shedding rates show great variability, a progressive increase in cercarial production was observed in the first weeks of the cercarial shedding periods, probably in relation to the demography of intramollusean larval stages. Under 12:12 light-dark cycling condition;, it, albuferensis cercariae emerged in the light, and the rhythm was …

Proteomic analysis of the pinworm Syphacia muris (Nematoda: Oxyuridae), a parasite of laboratory rats

Syphacia muris (Nematoda: Oxyuridae) is a ubiquitous nematode that commonly infects rats in the laboratory which can interfere in the development of biological assays. The somatic extract of S. muris adults collected from infected rats was investigated using a proteomic approach. A shot-gun liquid chromatography/tandem mass spectrometry procedure was used. We used the MASCOT search engine (Matrix-Science) and ProteinPilot software v2.0 (Applied Biosystems) for the database search. A total of 359 proteins were accurately identified from the worms. The largest protein families consisted of metabolic enzymes and those involved in the nucleic metabolism and cell cycle. Proteins of transmembrane…

Larval trematode infections in freshwater gastropods from the Albufera Natural Park in Spain

AbstractMalacological samplings were made from January 1994 to December 1996 in the Albufera Natural Park (Valencia, Spain) to trace the dynamics of molluscan populations and the prevalence and intensity of infection by larval trematodes. A total of 10,533 freshwater gastropods belonging to seven species (Lymnaea auricularia, L. truncatula, L. palustris, L. peregra, Bithynia tentaculata, Physa acuta and Gyraulus chinensis) was examined, and 110 (1.04%) were found to harbour some of the nine distinguishable types of cercariae, namely four echinostome cercariae (Hypoderaeum conoideum, Echinoparyphium recurvatum, Euparyphium albuferensis, and Echinostoma sp.), four furcocercous cercariae, and …

Soil-transmitted Helminth Infections in Schoolchildren of Laguna de Perlas (Nicaragua).

Soil-transmitted helminth (STH) prevalence, intensity, polyparasitism and co-infections in 425 children from 3 schools of Laguna de Perlas (Nicaragua) were investigated. Single stool samples were analysed by the formalin-ether method and the Kato-Katz. A total of 402 (94.6%) children were infected. Trichuris trichiura 308 (72.4%), Ascaris lumbricoides 115 (27.1%) and Hookworms 54 (12.7%) were the most prevalent STHs. Polyparasitism (322; 75.8%) with two species was most prevalent (109; 25.6%). T. trichiura with A. lumbricoides (19.3%) and T. trichiura with Hookworm (6.8%) were the most common combinations. Positive associations were observed between T. trichiura and A. lumbricoides and T. t…

Additional file 2: of Prevalence of intestinal parasites, with emphasis on the molecular epidemiology of Giardia duodenalis and Blastocystis sp., in the Paranaguá Bay, Brazil: a community survey

Table S2. The frequency of single and multiple infections by enteric protozoan and helminth parasites over the total individuals infected by at least one enteric pathogen (n = 353) in Paranaguá, Paraná, Brazil, 2015–2016. (DOCX 28 kb)

Echinostomes in the definitive host: a model for the study of host-parasite relationships.

Echinostomes are hermaphroditic digeneans that parasitize, as adults, numerous vertebrate hosts of all classes. In this chapter, the main features of the development of adult echinostome in the definitive host are analyzed in detail. The stage of the echinostome in the definitive host undergoes a number of features such as metacercarial excystment, establishment, habitat location, adult development, mate, and release of eggs. These features are documented with an emphasis in their potential use as experimental models. The analysis is focused on members of the genus Echinostoma, although members of other genera of the Echinostomatidae are mentioned when they are relevant to the discussion. A…

Development and pathology of echinostoma caproni in experimentally infected mice

In the present article, several parasitological features of mice, each experimentally infected with 75 metacercariae of Echinostoma caproni (Trematoda: Echinostomatidae), were studied during the first 12 wk postinfection. Moreover, the early pathological responses also were analyzed and compared with data previously published on other host species of E. caproni to gain further insight into the factors determining worm rejection or establishment of chronic infections. The results obtained show that the pattern of E. caproni infection in mice is consistent with a highly compatible host–parasite system. This combination is characterized by a high worm establishment, high egg output, and long s…

Echinostoma caproni (Trematoda): differential in vivo cytokine responses in high and low compatible hosts.

In order to investigate the factors determining the expulsion of intestinal trematodes, we have analyzed the in vivo cytokine responses at several levels and the local responses against Echinostoma caproni (Trematoda) in two host species displaying different compatibility with the parasite. The response of the high compatible host (mice) is characterized by a mixed Th1/Th2 phenotype in the spleen, Peyer's patches and mesenteric lymph nodes. At the intestine, a marked Th1 response with a marked increase of IFN-γ together with elevated number of mucosal neutrophils and expression of induced nitric oxide synthase were observed. The responses in the host of low compatibility (rats) with the par…

Enteroparasites in Preschool Children on the Pacific Region of Nicaragua

The aim of this study was to determine for the first time the prevalence of enteroparasites in preschool children originating from the seven departments of the Pacific region in Nicaragua. One stool sample of each of 1,217 children, from 6 months to 5 years of age, was collected and personal data were recorded on delivery of the container. Samples fixed in 10% formalin were processed by a formol-acetate concentration and a modified Ziehl–Neelsen technique. The overall prevalence of enteroparasite infections was 68.2% with a total of at least 20 species. Blastocystis hominis (45.5%), Giardia intestinalis (31.7%), Trichuris trichiura (8.2%), and Ascaris lumbricoides (5.2%) were the most preva…

Diagnosis of Human Trematode Infections

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver, and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international t…

The transcriptome of Echinostoma caproni adults: further characterization of the secretome and identification of new potential drug targets.

Abstract Echinostomes are cosmopolitan parasites that infect a large number of different warm-blooded hosts, both in nature and in the laboratory. They also constitute an important group of food-borne trematodes of public health importance mainly in Southeast Asia and the Far East. In addition, echinostomes are an ideal model to study several aspects of intestinal helminth biology, since they present a number of advantages. For example, echinostomes are large worms whose life cycle is relatively easy to maintain in the laboratory. Recently, several studies documented their great value in the study of intestinal helminth–vertebrate host relationship. Detailed knowledge of their genome, trans…

New Insights into the Treatment of Foodborne Trematode Infections

Immunological Characterization of Somatic and Excretory–Secretory Antigens of Echinostoma caproni (Trematoda: Echinostomatidae) in Experimentally Infected Rats

The antigenic properties of somatic (SoP) and excretory-secretory products (ESP) of Echinostoma caproni were studied in experimentally infected rats. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis demonstrated a total of 15 and 9 major polypeptides, in the molecular weight range 10-165 kDa, in SoP and ESP products, respectively. Further analysis revealed some common as well as several unique polypeptides for each type of extract. A total of 2 polypeptides, weighing 58 and 115 kDa, were found in both types of antigen. Indirect enzyme-linked immunosorbent assay analysis using both types of antigens showed that rats developed a weak and slow response in infections with E. caproni. …

Analysis of the tegument of Zygocotyle lunata (Trematoda: Paramphistomidae) adults by scanning electron microscopy.

Paramphistomiasis is a parasitic disease caused by various species of the Paramphistomidae. These species mainly affect domestic and wild ruminants; the economic impact of these diseases is often underestimated. Traditionally, the identification of paramphistomes has been difficult and has been based on morphological aspects such as the body shape, the position of the esophagus and cecae, or the tegumental papillae. Despite the many investigations regarding the tegumental papillae for other paramphistomes, very few efforts have been made using Zygocotyle lunata, partly because many authors differ with respect to the importance of papillae in the classification of paramphistomids. Herein, we…

Proteomics of foodborne trematodes

Abstract Food-borne trematodiases are among the most neglected tropical diseases, not only in terms of research funding, but also in the public media. The Trematoda class contains several species identified as the causal agents of these diseases whose biological cycle, geographical distribution and epidemiology have been well characterised. The diagnosis of these diseases is based on parasitological techniques and only a limited number of drugs are currently available for treatments, most of which are unspecific. Therefore, in-depth studies to identify new and specific targets for both effective diagnosis and treatments are urgently needed. Currently, little molecular information is availab…

History of echinostomes (Trematoda)

AbstractEchinostomatidae (Trematoda) is the largest family within the class Trematoda. Members of this family have been studied for many years in relation to their utility as basic research models in biodiversity and systematics and also as experimental models in parasitology since they offer many advantages. Echinostomes have contributed significantly to numerous developments in many areas studied by parasitologists and experimental biologists. In this review, we examine the history of the echinostomebased studies from the beginnings to the present. For this purpose, we have divided the history of echinostomes into four periods (i.e. 18th and 19th centuries, first half of the 20th century,…

Interleukin-25-mediated resistance against intestinal trematodes does not depend on the generation of Th2 responses

AbstractInterleukin-25 (IL-25) is recognized as the most relevant initiator of protective Th2 responses in intestinal helminth infections. It is well known that IL-25 induces resistance against several species of intestinal helminths, including the trematode Echinostoma caproni. E. caproni has been extensively used as an experimental model to study the factors determining the resistance to intestinal infections. Herein, we assessed the role of IL-25 in the generation of resistance in mice to E. caproni infections. ICR mice are permissive hosts for E. caproni in which chronic infections are developed in relation to the lack of IL-25 production in response to primary infection and the consequ…

Additional file 4: of Definitive host influences the proteomic profile of excretory/secretory products of the trematode Echinostoma caproni

Biological process-based classification of proteins overexpressed in mice. Significantly overexpressed proteins in the excretory/secretory products of Echinostoma caproni adults obtained from mice, classified according to their Gene Ontology (GO)-predicted biological process. Pie chart represents the number of proteins assigned to each GO category (biological process, level 4). Proteins included in each category are listed below the graph. (PPTX 118 kb)

Echinostoma caproni: kinetics of IgM, IgA and IgG subclasses in the serum and intestine of experimentally infected rats and mice.

The kinetics of specific immunoglobulin M, A and IgG subclasses against Echinostoma caproni (Trematoda: Echinostomatidae) were analyzed in serum and intestinal fluid of two host species (Wistar rats and ICR mice) in which the course of the infection markedly differs. In rats, the worms were rapidly expelled, whereas E. caproni evokes in mice long-lasting infection. The pattern of antibody responses in both serum and intestinal samples was different in each host species. Serum responses in mice were characterized by significant increases of IgM, IgA, total IgG, IgG1 and IgG3, but not IgG2a. In contrast, serum responses in rats showed elevated levels of IgM, probably in relation to thymus-ind…

Euparyphium albuferensis and Echinostoma friedi (Trematoda: Echinostomatidae): Experimental cercarial transmission success in sympatric snail communities

Euparyphium albuferensis and Echinostoma friedi cercarial infectivity to four species of sympatric snails was exam- ined under single- or multiple-choice laboratory conditions to show the level of parasite-snail host compatibility. Radix peregra, Lymnaea fuscus, Physella acuta and Gyraulus chinensis act as second intermediate hosts of both parasite species although differ- ent cercarial transmission success (CTS) was observed. In single-host experiments, R. peregra and P. acuta showed a high de- gree of compatibility with E. albuferensis, while only P. acuta in the case of E. friedi. In two-choice snail communities, a snail with high CTS increased the values of another with low compatibilit…

Intestinal symptoms and Blastocystis load in schoolchildren of Paranaguá Bay, Paraná, Brazil

ABSTRACT The symptomatology of Blastocystis cannot be attributed to any particular subtype, although can be related to a high Blastocystis infection load. One stool sample from each of 217 schoolchildren of Vale de Sol Paranaguá Bay (Paraná, Brazil) was collected. Three milliliters of each fixed stool sample were processed applying the formalin-ether concentration technique. After obtaining the overall prevalence of intestinal parasites, quantification was carried out in Blastocystis positive samples. A total of 75/217 (34.6%) children suffered from intestinal symptoms (abdominal pain and/or persistent diarrhea), of whom 41.3% (31/75) presented moderate/heavy Blastocystis load with a statis…

Resistance against Echinostoma caproni (Trematoda) secondary infections in mice is not dependent on the ileal protein production

Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode, which has been widely employed to investigate the factors determining the rejection of intestinal helminths. Protein production patterns of intestinal epithelial cells are related to the infection-induced changes that determine the course of E. caproni infections. Herein, we compare the protein production profiles in the ileum of four experimental groups of mice: control; infected; dewormed and reinfected. Worm burdens were significantly lower in secondary infections, confirming the generation of partial resistance to homologous secondary infections in mice. However, quantitative comparison by 2D-DIGE showed that …

The transcriptome analysis of Strongyloides stercoralis L3i larvae reveals targets for intervention in a neglected disease.

Background: Strongyloidiasis is one of the most neglected diseases distributed worldwide with endemic areas in developed countries, where chronic infections are life threatening. Despite its impact, very little is known about the molecular biology of the parasite involved and its interplay with its hosts. Next generation sequencing technologies now provide unique opportunities to rapidly address these questions. Principal Findings: Here we present the first transcriptome of the third larval stage of S. stercoralis using 454 sequencing coupled with semi-automated bioinformatic analyses. 253,266 raw sequence reads were assembled into 11,250 contiguous sequences, most of which were novel. 8037…

Redescription ofPhysaloptera brevivaginata Seurat, 1917 (Nematoda: Physalopteridae) from the batMyotis blythii (Tomes) (Chiroptera: Vespertilionidae) in Spain

Physaloptera brevivaginata Seurat, 1917 (Nematoda: Physalopteridae) is redescribed. Seurat's (1917) original description of this species was based on a single immature female. Detailed morphological study of several males, mature and, above all, immature females from the stomach of the lesser mouse-eared batMyotis blythii (Tomes) (Chiroptera: Vespertilionidae) in Spain, has elucidated many new morphological characters. This physalopterid species is distinguished from other closely-related species by the lengths of the body and spicules, the equatorial position of the vulva, the morphology of the female reproductive system and by a small conical process on the tail of mature females.M. blyth…

Echinostoma caproni: identification of enolase in excretory/secretory products, molecular cloning, and functional expression.

In order to investigate molecules that could be involved in host-trematode relationships, we have analysed the excretory/secretory products (ESP) of Echinostoma caproni following a proteomic approach. Actin, Gluthathione S-transferase (GST) and enolase have been identified in the ESP. Enolase, observed to be one of the most abundant proteins, was further characterized. The molecular cloning and in vitro expression in Escherichia coli of E. caproni enolase allowed us to determine that the protein contains 431 amino acids and a theoretical MW of 46272 Da. E. caproni enolase shows high homology to other trematode enolases. The recombinant protein binds specifically to human plasminogen in vitr…

Th17 responses in Echinostoma caproni infections in hosts of high and low compatibility.

In order to investigate the factors determining the expulsion of intestinal helminths, we have analyzed the in vivo expression of IL-17, TGF-β and IL-23 in several tissues of two host species displaying different compatibility with Echinostoma caproni (Trematoda). We did not observe upregulation of these cytokines in any of the tissues of the high compatible host (mice). In contrast, the responses in the host of low compatibility (rats) with the parasite were markedly different. Significant increases in the expression of IL-17 and TGF-β were observed in the Peyer's patches and the intestine from the 2 to 8 weeks post-infection. The expression of IL-23 was upregulated from 2 to 4 weeks post-…

Protective immunity against Echinostoma caproni in rats is induced by Syphacia muris infection.

Syphacia muris (Nematoda: Oxyuridae) is a ubiquitous nematode that commonly infects rats in the laboratory and can interfere with the development of unrelated biological assays. In this context, we analysed the effect of a patent S. muris infection in Wistar rats on a superimposed infection with the intestinal trematode, Echinostoma caproni (Trematoda: Echinostomatidae). The results indicate that in the rats, infection with S. muris induces an immunity against a subsequent infection with E. caproni, although each parasite occupies different niches in the host. Echinostoma caproni worm recovery was significantly decreased in the rats primarily infected with S. muris and, at 3 and 4 weeks pos…

Interactions related to non-host snails in the host-finding process of Euparyphium albuferensis and Echinostoma friedi (Trematoda: Echinostomatidae) miracidia.

In order to determine whether the miracidia of Euparyphium albuferensis and Echinostoma friedi are sensitive to their host snail (HS) and capable of discriminating between HS and non-host snails (NHS), or whether these NHS can interfere and thus reduce the infection rates (decoy effect), a total of three experiments were conducted with HS, NHS and snail-conditioned water (SCW). Gyraulus chinensis is the HS for E. albuferensis miracidia, while Physa acuta, Radix peregra and Lymnaea fuscus are considered NHS. For E. friedi miracidia R. peregra, G. chinensis and L. fuscus are the HS, while P. acuta is the NHS. The NHS R. peregra produces the greatest decoy effect on Euparyphium albuferensis mi…

Biomphalaria Snails and Larval Trematodes

Biomphalaria snails and larval trematodes , Biomphalaria snails and larval trematodes , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

Screening trematodes for novel intervention targets: a proteomic and immunological comparison of Schistosoma haematobium, Schistosoma bovis and Echinostoma caproni

SUMMARYWith the current paucity of vaccine targets for parasitic diseases, particularly those in childhood, the aim of this study was to compare protein expression and immune cross-reactivity between the trematodes Schistosoma haematobium, S. bovis and Echinostoma caproni in the hope of identifying novel intervention targets. Native adult parasite proteins were separated by 2-dimensional gel electrophoresis and identified through electrospray ionisation tandem mass spectrometry to produce a reference gel. Proteins from differential gel electrophoresis analyses of the three parasite proteomes were compared and screened against sera from hamsters infected with S. haematobium and E. caproni fo…

The effect of glycosylation of antigens on the antibody responses against Echinostoma caproni (Trematoda: Echinostomatidae).

SUMMARYIn the present study, we analyse the effect of glycosylation inEchinostoma caproni(Trematoda: Echinostomatidae) antigens in antibody responses against the parasite in experimentally infected mice. It has been previously demonstrated that the mouse is a host of high compatibility withE. caproniand develops elevated responses of IgG, IgG1, IgG3 and IgM as a consequence of the infection, though the role of glycans in these responses remains unknown. To this purpose, the responses generated in mice against non-treated excretory/secretory antigens ofE. caproniwere compared with those observed after N-deglycosylation, O-deglycosylation and double deglycosylation of the antigens by indirect…

Zygocotyle lunata: Proteomic analysis of the adult stage

The somatic extract of Zygocotyle lunata (Trematoda: Paramphistomidae) adults collected from experimentally infected mice was investigated using a proteomic approach to separate and identify tryptic peptides from the somatic extract of Z. lunata adult worms. A shot-gun liquid chromatography/tandem mass spectrometry procedure was used. We used the MASCOT search engine (Matrix-Science) and ProteinPilot software v2.0 (Applied Biosystems) for the database search. A total of 36 proteins were accurately identified from the worms. The largest protein family consisted of metabolic enzymes. Structural, motor and receptor binding proteins and proteins related to oxygen transport were identified in th…

Proteomic analysis of Strongyloides stercoralis L3 larvae

SUMMARYStrongyloidiasis can be perpetuated by autoinfection with the filariform larvae L3, causing asymptomatic chronic infections and creating a population of carriers, affecting not only developing countries. So far, very little is known about the proteins that interact with the human host, and few proteins from the infective Strongyloides stercoralis L3 have been characterized. Here, we report results obtained from a proteomic analysis of the proteins from S. stercoralis L3 larvae obtained from patients. Since the genome of S. stercoralis is not yet available, we used proteomic analysis to identify 26 different proteins, 13 of them released by short digestion with trypsin, which could re…

Effects of Nonschistosome Larval Trematodes on Biomphalaria Snails

This chapter examines the most salient literature on the development of nonschistosome larval digeneans in Biomphalaria spp. (members of the ­superfamilies Clinostomoidea, Diplostomoidea, Echinostomatoidea, Paramphistomoidea, and Pronocephaloidea). For this purpose, the general biology of the nonschistosome trematode species that use Biomphalaria spp. as ­intermediate hosts are ­analyzed. Thereafter, the main features of these parasitic infections are studied with ­particular emphasis on topics such as the effect of the infections on the snail, the antagonism and/or competition between different digenean species in the snail, the ­immunology of the infection, and the genomic and proteomic a…

Leucine aminopeptidase is an immunodominant antigen of Fasciola hepatica excretory and secretory products in human infections.

ABSTRACT The liver fluke Fasciola hepatica parasitizes humans and ruminant livestock worldwide, and it is now being considered a reemerging zoonotic disease, especially in areas in which it is endemic, such as South America. This study investigates the immune response to excretory and secretory products produced by F. hepatica in a group of patients from the Peruvian Altiplano, where the disease is highly endemic. Using a proteomic approach and immunoblotting techniques, we have identified the enzymes leucine aminopeptidase (LAP) and phosphoenolpyruvate carboxykinase as immunodominant antigens recognized by sera from fasciolosis patients. An indirect enzyme-linked immunosorbent assay using …

Chapter 3 Recent Advances in the Biology of Echinostomes

This chapter examines the significant literature on the biology of echinostomes. The members of the family Echinostomatidae are medically and veterinary-important parasitic flatworms that invade humans, domestic animals and wildlife and also parasitize in their larval stages numerous invertebrate and cold-blooded vertebrate hosts. All echinostomes possess a complicated lifecycle expressed by: (i) alternation of seven generations known as the adult, egg, miracidium, sporocyst, redia, cercaria and metacercaria, and (ii) inclusion of three host categories known as the definitive host and first and second intermediate hosts. Moreover, echinostomes have served as experimental models in parasitol…

Echinostoma caproni (Trematoda): differential in vivo mucin expression and glycosylation in high- and low-compatible hosts.

Enhanced mucus production and release appears to be a common mechanism for the clearance of intestinal helminths, and this expulsion is normally mediated by Th2-type immune responses. To investigate the factors determining the expulsion of intestinal helminths, we have analysed in vivo expression of mucin genes at the site of infection in two host species displaying different compatibility with Echinostoma caproni (Trematoda). Surprisingly, a general down-regulation on mucin mRNA expression was detected in low-compatible hosts (rats) coinciding with the development of Th2/Th17 responses and the early rejection of the worms from the intestinal lumen. This suggests the existence of a mechanis…

Altered Protein Expression in the Ileum of Mice Associated with the Development of Chronic Infections with Echinostoma caproni (Trematoda)

Background Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been extensively used as experimental model to investigate the factors determining the expulsion of intestinal helminths or, in contrast, the development of chronic infections. Herein, we analyze the changes in protein expression induced by E. caproni infection in ICR mice, a host of high compatibility in which the parasites develop chronic infections. Methodology/Principal Findings To determine the changes in protein expression, a two-dimensional DIGE approach using protein extracts from the intestine of naïve and infected mice was employed; and spots showing significant differential expression…

Echinostoma friedi: the effect of age of adult worms on the infectivity of miracidia.

AbstractThe effect of ageing of adults ofEchinostoma friedi(Trematoda: Echinostomatidae) on the infectivity of miracidia yielded was analysed. Miracidia were obtained after hatching of eggs obtained from adult worms ofE. friedicollected weekly during the course of experimental infections in golden hamsters. Miracidial infectivity, measured in terms of percentage of infection inLymnaea peregra, was significantly influenced by the age of the adult worms from which the miracidia were derived. Infective miracidia only were obtained from adult worms in the age range from 4 to 9 weeks post-infection. Infectivity was maximal in those miracidia derived from adults collected 8 and 9 weeks post-infec…

Additional file 5: of Definitive host influences the proteomic profile of excretory/secretory products of the trematode Echinostoma caproni

Molecular function-based classification of proteins overexpressed in mice. Significantly overexpressed proteins in the excretory/secretory products of Echinostoma caproni adults obtained from mice, classified according to their Gene Ontology (GO)-predicted molecular function. Pie chart represents the number of proteins assigned to each GO category (molecular function, level 3). Proteins included in each category are listed below the graph. (PPTX 77 kb)

Classic Models for New Perspectives: Delving into Helminth–Microbiota–Immune System Interactions

Whilst a wealth of data indicate that infections by gastrointestinal helminths are accompanied by significant alterations in the composition of the vertebrate gut flora, little is known of the immune-molecular mechanisms that regulate host-parasite-microbiota interactions. 'Traditional' experimental models of gastrointestinal helminthiases, in which the role(s) of each of the components of this triad can be tested, provide an opportunity to advance research in this area. In this article, we propose the Echinostoma caproni-mouse system as a potentially useful tool for studies of the role of the host gut microbiota in preventing pathology and inducing parasite clearance via interleukin (IL)-2…

Identification of enolase as a plasminogen-binding protein in excretory-secretory products ofFasciola hepatica

AbstractWe have followed a combined proteomic approach to identify proteins of Fasciola hepatica that could be involved in host–parasite interactions. Using two-dimensional gel electrophoresis, far Western immunoblot and mass spectrometry analyses, we have identified the enolase enzyme, present in the excretory/secretory materials of F. hepatica, as a human plasminogen-binding protein. This enzyme has an apparent molecular weight of 47 kDa with pI ranging from 6.2 to 7.2. These results suggest that enolase could act as a plasminogen receptor.

Partial resistance to homologous challenge infections of the digenean Echinostoma caproni in ICR mice

AbstractIn the present paper, we analyse the effect of a primary infection of ICR mice with Echinostoma caproni (Trematoda: Echinostomatidae) on the generation of resistance against homologous challenge infections. In ICR mice, E. caproni induces chronic infections concomitantly with strong responses characterized by the development of T-helper 1 (Th1)-type local immune responses with elevated levels of local interferon-gamma (IFN-γ) and inflammatory and antibody responses. Here, the effect of the response generated against a primary infection with E. caproni in the generation of resistance against subsequent homologous infections was analysed. For this purpose, ICR mice were challenged wit…

Additional file 3: of Definitive host influences the proteomic profile of excretory/secretory products of the trematode Echinostoma caproni

Identification details of differentially expressed proteins. Description of data: Details of the identification of differentially expressed proteins using X!Tandem and MS-GF+ search engines on the Echinostoma caproni genome and transcriptome databases and BLASTp analysis against NCBInr protein database. Spot numbers refer to gel image in Fig. 2. (DOCX 19 kb)

The life cycle and transmission dynamics of the larval stages ofHypoderaeum conoideum

AbstractThe morphology of the different larval stages and life cycle ofHypoderaeum conoideum(Trematoda: Echinostomatidae) are described. The freshwater snail speciesLymnaea peregra(Gastropoda: Lymnaeidae) serves as the natural first intermediate host and this andL. corvusserve as experimental first intermediate hosts. These and other freshwater snails, such asPhysella acutaandGyraulus chinensis, in turn serve as second intermediate hosts. Adult worms were obtained from chicks and ducks, but not from rats, mice and golden hamsters. The morphology of the larval stages is compared with previous work onH. conoideum. Several aspects of the biology of the life history stages are described with em…

Reduced prevalence of soil-transmitted helminths and high frequency of protozoan infections in the surrounding urban area of Curitiba, Paraná, Brazil

Human populations living in the surrounding urban areas of large Brazilian cities have increased vulnerability to intestinal parasites. However, the epidemiological scenario of soil-transmitted helminths (STH) in Curitiba, Paraná's main city, remains largely unknown. To bridge this gap of knowledge, this study aims to determine the prevalence of intestinal parasites and to investigate potential transmission pathways of the most prevalent species detected. We conducted a cross-sectional epidemiological study between July and September 2014 among schoolchildren in urban and peri-urban (deprived) areas of the municipality of Campo do Tenente, Curitiba. A total of 549 stool samples were used fo…

Identification of antigenic proteins from Echinostoma caproni (Trematoda) recognized by mouse immunoglobulins M, A and G using an immunoproteomic approach.

Antigenic proteins of Echinostoma caproni (Trematoda) against mouse IgM, IgA, IgG, IgG1 and IgG2a were investigated by immunoproteomics. Excretory/secretory products (ESP) of E. caproni separated by two-dimensional (2D) gel electrophoresis were transferred to nitrocellulose membranes and probed with the different mouse immunoglobulin classes. A total of four proteins (enolase, 70 kDa heat-shock protein (HSP-70), actin and aldolase) were accurately identified. Enolase was recognized in eight different spots of which seven of them were detected in the expected molecular weight and were recognized by IgA, IgG or IgG and IgG1. Another spot identified as enolase at 72 kDa was only recognized by …

Differential expression and glycosylation of proteins in the rat ileal epithelium in response to Echinostoma caproni infection.

Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been used as experimental model to investigate the factors determining the expulsion of intestinal helminths. We analyze the changes in the protein expression and glycosylation induced by E. caproni in Wistar rat, a host of low compatibility in which the parasites are rapidly rejected. To determine the changes in protein expression, two-dimensional difference gel electrophoresis was employed using protein extracts from the intestine of naïve and infected rats. The patterns of glycosylation were analyzed by lectin blotting. Those spots showing differential expression or glycosylation were analyzed by mass s…

Prevalence of intestinal parasites, with emphasis on the molecular epidemiology of Giardia duodenalis and Blastocystis sp., in the Paranaguá Bay, Brazil: a community survey

BACKGROUND: Intestinal protozoan parasites are major contributors to the global burden of gastrointestinal disease causing significant socioeconomic consequences. Children living in resource-poor settings with restricted access to water and sanitary services are particularly at risk of these infections. METHODS: A prospective, community-based, cross-sectional survey was conducted in Paraná (southern Brazil) between May 2015 and May 2016. A total of 766 stool samples were individually collected from volunteers (male/female ratio: 0.99; age range: 0-76 years) and used for investigating the presence of intestinal helminth and protozoan species by routine microscopic procedures including the Ka…

Antibody trapping: A novel mechanism of parasite immune evasion by the trematode Echinostoma caproni

Background Helminth infections are among the most prevalent neglected tropical diseases, causing an enormous impact in global health and the socioeconomic growth of developing countries. In this context, the study of helminth biology, with emphasis on host-parasite interactions, appears as a promising approach for developing new tools to prevent and control these infections. Methods/Principal findings The role that antibody responses have on helminth infections is still not well understood. To go in depth into this issue, work on the intestinal helminth Echinostoma caproni (Trematoda: Echinostomatidae) has been undertaken. Adult parasites were recovered from infected mice and cultured in vi…

Development of an antibody-based capture enzyme-linked immunosorbent assay for detecting echinostoma caproni (trematoda) in experimentally infected rats: kinetics of coproantigen excretion

The present study reports on the development of a coproantigen capture enzyme-linked immunosorbent assay (ELISA) for detecting Echinostoma caproni in experimentally infected rats. The capture ELISA was based on polyclonal rabbit antibodies that recognize excretory–secretory (ES) antigens. The detection limit of pure ES was 3 ng/ml in sample buffer and 60 ng/ml in fecal samples. The test was evaluated using a follow-up of 10 rats experimentally infected with 100 metacercariae of E. caproni, and the results were compared with those of other diagnostic methods such as parasitological examination and antibody titers determined by indirect ELISA. Coproantigens were detected in all the infected r…

Subcutaneous injection of exosomes reduces symptom severity and mortality induced by Echinostoma caproni infection in BALB/c mice.

Recent studies have shown the importance of exosomes in the host-parasite relationship. These vesicles are an important part of the excretory/secretory pathway for proteins with the potential to alter immune responses. Therefore, in the present study, we examined the immunomodulatory role of exosomes in BALB/c mice using Echinostoma caproni as an experimental model of intestinal helminth infection. For this purpose, BALB/c mice were injected twice s.c. with purified exosomes of E. caproni, followed by experimental infection. We report a delay in the development of the parasite in mice immunised with exosomes, a concomitant reduced symptom severity and increased survival upon infection. Immu…

Interleukin-25 Induces Resistance Against Intestinal Trematodes

AbstractEchinostoma caproni is an intestinal trematode that has been extensively used as an experimental model to investigate the factors determining the resistance to intestinal helminths or the development of chronic infections. ICR mice are permissive hosts for E. caproni in which chronic infections are developed, concomitantly with local Th1 responses, elevated levels of local IFN-γ, inflammation and antibody responses. However, mice develop partial resistance to homologous challenge infections after cure of a primary infection, which converts this subject into an adequate model for the study of the mechanisms generating resistance against intestinal helminths. The purpose of the presen…

Additional file 5 of Interleukin-25-mediated resistance against intestinal trematodes does not depend on the generation of Th2 responses

Additional file 5: Fig. S4. Treatment of IL-25-treated-mice with mα-IL-4Rα or rIL-13Rα2 reduces STAT6 activation. Indirect immunofluorescence with anti-STAT6 (red) and anti-STAT6P (red) on intestinal tissue of IL-25-treated-mice that were also treated with mα-IL-4Rα or rIL-13Rα2 at 2 weeks post-primary infection. Scale bar: 30 μm.

Additional file 4 of Interleukin-25-mediated resistance against intestinal trematodes does not depend on the generation of Th2 responses

Additional file 4: Fig. S3. Secondary E. caproni infection induces expansion of tuft cells and GATA3 + cells. (A) Schematic representation of the experimental protocol; (B) Counts of tuft cell populations and (C) GATA3 + cells 2 weeks after primary infection (2 wppi), 2 weeks after treatment with pzq (2 wppt) and 2 weeks after secondary infection with E. caproni (2 wpsi). Vertical bars represent the standard deviation. a: significant differences with respect to naïve mice controls; b: significant differences between groups (p

Additional file 2 of Interleukin-25-mediated resistance against intestinal trematodes does not depend on the generation of Th2 responses

Additional file 2: Fig. S1. Treatment of mice with rIL-4 or rIL-13 induces a Th2 response and RELM-β overexpression in response to primary Echinostoma caproni and infection but not resistance to infection. (A) expression of cytokine mRNA in the intestinal tissue of rIL-4-treated or rIL-13-treated mice at 2 weeks post-primary infection with E. caproni; (B) expression of RELM-β mRNA in the intestinal tissue (F) of naïve mice, non-infected rIL-4- or rIL-13-treated mice and infected rIL-4- or rIL-13-treated mice at 2 weeks post-primary infection. The relative quantities (RQ) of cytokine genes are shown after normalization with β-actin and standardization of the relative amount against day 0 sam…

Additional file 3 of Interleukin-25-mediated resistance against intestinal trematodes does not depend on the generation of Th2 responses

Additional file 3: Fig. S2. Immunohistochemical images showing changes in tuft cell populations (A) and GATA3+ cells (B) 2 weeks after primary infection (2 wppi), 2 weeks after treatment with praziquantel (2 wppt) and 2 weeks after secondary infection with E. caproni (2 wpsi). Scale bar: 10 μm.